Caenorhabditis elegans and Drosophila, we performed evolutionary bioinformatics analysis of the mammalian growth cone phosphorylation sites. Although these sites were generally conserved within vertebrates, they were not necessarily conserved in these invertebrate model organisms. In particular, high-frequency phosphorylation sites (> 20 times) were less conserved than low-frequency sites. Taken together, the mammalian growth cones contain a large number of vertebrate-specific phosphorylation sites and stronger dependence upon MAPK/JNK than C. elegans or Drosophila. We conclude that axon growth/regeneration likely involves many vertebrate-specific phosphorylation sites.The growth cone is essential for nerve growth and axon regeneration, which directly form and rearrange the neural network. Recently, to clarify the molecular signaling pathways in the growth cone that utilize protein phosphorylation, we performed a phosphoproteomics study of mammalian growth cone membranes derived from the developing rodent brain and identified > 30,000 phosphopeptides from ~ 1200 proteins. We found that the phosphorylation sites were highly proline directed and primarily mitogen-activated protein kinase (MAPK) dependent, due to particular activation of c-jun N-terminal protein kinase (JNK), a member of the MAPK family. Because the MAPK/JNK pathway is also involved in axon regeneration of invertebrate model organisms such The online version of this article (10.1186/s13041-019-0476-x) contains supplementary material, which is available to authorized users. The growth cone, a highly motile structure at the tip of extending axons in developing or regenerating neurons , is crucTo further investigate molecular signaling in growth cones, we focused on protein phosphorylation, the most important regulatory mechanism in many cellular processes . PhosphoCaenorhabditis elegans [The MAPK family includes extracellular signal–regulated kinase, p38, and JNK, among which JNK appeared to be the most likely kinase candidate for mammalian GCM phosphorylation. First, several recent reports showed that JNK is involved in multiple steps of mammalian brain development –11. Seco elegans . TogetheC. elegans and Drosophila, using comparative genomics data in “Ensembl” [Thus, to understand and characterize MAPK signaling in the GCM, we used bioinformatics to examine whether the phosphorylation sites of the mammalian GCM proteins that were identified using phosphoproteomics were conserved within a wide range of animals. If so, the signaling pathways involving those phosphosites were expected to be widely conserved from mammals to nematodes or insects. We first made an evolutionary comparison between vertebrates and invertebrates such as Ensembl” . SurprisEnsembl” , a kinasC. elegans axon regeneration [C. elegans, although JNK is activated in neurons of both organisms. We conclude that the molecular signaling in mammalian growth cones for axon growth/regeneration may more frequently use evolutionarily newer phosphoproteins or phosphorylated sites that depend on MAPK/JNK, in addition to older ones that are also present in invertebrate phosphoproteins. These newly identified phosphorylated sites may have allowed more sophisticated signaling pathways that are more suitable for neural network formation in vertebrate brain, where the neuronal number is much larger than in invertebrates.In the case of downstream genes of DLK-JNK signaling in neration , few P-dneration , suggestAdditional file 1:Figure S1. Alignment of the P-directed GCM phosphoproteins emerging from the invertebrates. (PDF 9916 kb)Additional file 2:Methods and the legend to Figure S1. (DOCX 16 kb)


AbstractThis dataset contains information on the presence and distribution of sea turtles in Togo. Observations were carried out through a network of ten ecoguards , facilitated by five fishermen, and coordinated by a field technician, all under the supervision of a scientific coordinator. Data on the occurrence or direct observation of sea turtles on the Togolese coast from September 2012 to August 2013 is presented based on 740 occurrences. Sea turtles emerged approximately 130 million years ago and are the only marine forms of the reptilian class . They arCheloniamydas ), Olive ridley ), Loggerhead turtle ), Hawksbill turtle ), and Leatherback turtle ). According to the above-mentioned works, feeding, and reproduction are the main reasons explaining the presence of these species on the Togolese coast.As sea turtles migrate over thousands of kilometres, and the fact that they take tens of years to reach maturity, sea turtles serve as health indicators of coastal and marine environments, both locally and globally . In WestESMP), linking to the container terminal construction at the Lome Autonomous Port , a follow-up program for marine turtles was developed between September 2012 and August 2013, to determine the dynamics of their attendance on the Togolese coast. For this purpose, a monitoring protocol has been developed to collect data on the presence of marine turtles at the construction site of the terminal and its area of influence. The objective of this monitoring program was to verify the assumptions made in the ESIA report, which asserts the presence of marine turtles in the project construction zone, and to propose measures to reduce risks of disturbance and accidents of these animals caused by the construction works. The data collected also made possible to analyse the ecological parameters connected to the use of Togolese beaches by marine turtle species. In the following paragraphs, we present the data collection method used in this monitoring program.As part of the implementation of the Environmental and Social Management Plan . This company, established in Togo, carried out a project including the design, financing, construction, management, and operation of a private containers terminal at the port of Lomé. In compliance with the setting of the framework environmental law in Togo, an Environmental and Social Impact Assessment (ESIA) with an Environmental and Social Management Plan (ESMP) was carried out before the implementation of the project. Recommendations of this study required a sea turtle monitoring program entrusted to the NGO named AGBO-ZEGUE. Indeed, this NGO is specialized in monitoring populations of endangered marine and coastal species in Togo and West Africa.This marine turtle monitoring program was funded by the Thus, to carry out this monitoring of marine turtles along the Togolese coast, AGBO-ZEGUE has initiated and installed a network of ecoguards whose mission was to collect data on sea turtle attendance and egg-laying.As part of this monitoring program, five observation sites have been defined to cover the Togolese littoral zone where the construction work of the container terminal is likely to impact, in particular on the access of sea turtles to the coast to lay eggs Figure . The desSite 1: Length = 6 km; Going from the Ghana-Togo border to the Rond-Point of “Hotel de la Paix”. This site presents a sandstone favourable to the nesting of marine turtles. The site is under heavy light disturbance: the lights emitted at night by ships added to the lights of streetlights and buildings can influence the behaviour of egg-laying females.LCT container terminal and is one of the most affected areas by the port activities. The monitoring program took into account this site in order to evaluate the impact of construction activities on its attendance by sea turtles.Site 2: Length = 5.5 km. It extends from “Hotel de la Paix” to the main pier of the autonomous port of Lome. It corresponds to the construction site of the LCT. It is the longest site of the monitoring program. It is characterized by a beach-rock bench visible at low tide. This natural building is sometimes a serious handicap for female sea turtles coming to lay at low tide.Site 3: Length 10 km, from Gbetsogbe village to Kpogan. Like site 2, site 3 is also part of the zone of influence of the construction of LCT as the site 3. It has the distinction of having a dark beach back at night and therefore conducive to nesting behaviour of sea turtles. The beach-rock bench is present but of low amplitude. This supralittoral consists of sand grain favourable to the incubation of sea turtle eggs. This site is the second most frequented by marine turtles in Togo ) ) )  Figure , and 19 ) Figure . Figure Lepidochelysolivacea   Figure : Olive rCheloniamydas   Figure : Green tDermochelyscoriacea   Figure : LeatherGeneral spatial coverage: This monitoring program was carried out all over the Togolese coast. This coast stretches from Kodjoviakopé, the last Togo district before Togo-Ghana border to Aného, a city in Togo which borders Benin (Togo-Benin border). For the study, this area was subdivided into five sites.Coordinates: The study area is located between 6°6'32.4"N and 6°17'31.2"N Latitude; and 1°8'13.2"E and 1°49'1.2"E Longitude (DMS).Temporal coverage: The monitoring program was implemented from September 2012 to August 2013. During this period, the local guides do the patrols every day from 04:00 to 06:00 am.Study extent descriptionMonitoring was carried out by a network of ten ecoguards and five facilitator fishers. All activities of ecoguards and facilitators are coordinated by a technical facilitator coming from the NGO. The latter retrieves weekly all data recorded by ecoguards and strips them. In addition to this coordination, he participates in night patrols, in the surveillance of fishermen’s camps during the day and, when necessary, participates in the facilitation of the release of captured sea turtles. Data collected are then transmitted to the NGO scientific coordinator who analyses the data recorded and outputs summary results every semester.Sampling descriptionThe method of data collection is based on regular monitoring of nesting beaches and the different camps of fishermen. Surveillance is organized day and night. For security reasons, patrols at night were organized in the early morning between 04:00 and 06:00 am. Visits were carried out every day from September 2012 to August 2013. During the day, fishing camps are monitored between 10:00 am and 4:00 pm in order to recover and release the animals captured alive by these fishermen. This work is carried out according to the characteristics of the sites in particular the parameters related to the safety of the places and the work period of the coastal fishermen. The average observation effort per ecogard and per site varies between 60 and 90 hours per month. Two ecoguards positioned per site are chosen from the villages located at the ends of their site, and specifically educated for this study patrolled the sections on a daily basis collecting data. During patrols, ecoguards per site meet every day at a point on their site. This technique allows to cover all the highlights of their site. Thus, all information is collected systematically. Each turtle was identified to species and sex, and its carapace was measured with a tape following the technique by Object name: Darwin Core Archive BID-AF2015-0004-NAC Monitoring data of marine turtles on the Togolese coast over 2012–2013 years.Character encoding: UTF-8Format name: Darwin Core Archive formatFormat version: 1.0http://ipt-togo.gbif.fr/resource?r=marine_turtlesDistribution Publication date of data: 2018-04-17Language: EnglishLicences of use: Creative Commons Attribution (CC-BY) 4.0 LicenseMetadata language: EnglishDate of metadata creation: 2018-04-17Hierarchy level: Dataset


Phellinus linteus (PL) has been used as a traditional herbal medicine owing to its immune regulatory activity. Previous studies reported that PL grown on germinated brown rice (PBR) exerted immunomodulatory, anticancer, and anti-inflammatory activities. However, role of PBR on type I hypersensitive reactions has not been studied yet. We found that PBR contained more polyphenolic compounds than PL extract. Among fractions, PBR butanol fraction (PBR-BuOH) significantly contained the most amounts of total polyphenolic contents compared with all extracts or fractions. In this study, anti-allergic activity of PBR-BuOH was examined using in vitro and in vivo models of immunoglobulin E/antigen- (IgE/Ag-) stimulated allergy. The inhibitory activity of degranulation was higher in PBR-BuOH (IC50 41.31 ± 0.14 μg/mL) than in PL-BuOH (IC50 108.07 ± 8.98 μg/mL). We observed that PBR-BuOH suppressed calcium influx and the level of TNF-α and IL-4 mRNA expression in a dose-dependent manner. The phosphorylation of Fyn, Gab2, PI3K, Syk, and IκB protein is reduced by PBR-BuOH. Oral administration of PBR-BuOH inhibited allergic reactions including the extravasation of Evans blue dye, ear swelling, and infiltration of immune cells in mice with passive cutaneous anaphylaxis (PCA). These findings suggest that PBR-BuOH might be used as a functional food, a health supplement, or a drug for preventing type I hypersensitive allergic disease. The εRI) –11. The εRI) , corticoεRI) , aspirinεRI) , progestεRI) , and antεRI) . CurrentεRI) . Many reεRI) .Phellinus linteus (PL) has been traditionally used as a natural medicine in Asian countries for immune regulatory activities [Phellinus linteus grown on germinated brown rice (PBR), which is inoculated and cultured the mycelium of PL on germinated brown rice, that is, different from regular PL. In the previous studies, PBR exhibited physiological functions such as anti-inflammatory [εRI-mediated allergic responses. In addition, previously they reported that ergosterol peroxide and atractylenolide III were found in PBR but not in wild PL [β-glucan and γ-aminobutyric acid in PBR was higher than that in regular PL and brown rice [β-glucan and γ-aminobutyric acid inhibited the allergic activity in both IgE-mediated mast cells and type I hypersensitivity animal models [tivities –22. Wildtivities . In thisammatory , 25, antammatory , 27, andammatory . Unlike ammatory . The red wild PL , 30. Theown rice . Ergosteown rice , anti-inown rice , and antown rice . β-glucal models –37. HoweMycelia of PL (voucher number Kucari 0904) produced by solid-state culture and PBR (voucher number Kucari 0905) were kindly provided by the Cell Activation Research Institute  and deposited in the Herbarium at the College of Bioscience and Biotechnology, Konkuk University (Seoul) , 26. EacμL of each extract and fractions of PBR or PL (50 mg/mL) and gallic acid (0–500 μg/mL) was incubated with 20 μL of Folin–Ciocalteu reagent for 5 min. Then, 120 μL of 7% sodium carbonate (Na2CO3) was added and incubated at room temperature (RT) for 30 min. Absorbance was measured at 720 nm using a UV-Visible spectrophotometer . TPC was expressed as mg of gallic acid equivalents (GAEs)/g of dry mass.TPC in each extract was determined using a modified Folin–Ciocalteu method . In each2 [RBL-2H3 cells  were obtained from the American Type Culture Collection (ATCC) Biological Resource Center . Cells were cultured in minimum essential medium  supplemented with 15% fetal bovine serum  and 100 U/mL penicillin-streptomycin (Gibco) and were grown in a 75T cell culture flask at 37°C under humidified air containing 5% CO5 cells/well) were sensitized with 200 ng/mL of dinitrophenyl- (DNP-) specific IgE  overnight. After washing with PIPES buffer , cells were treated with PBR fractions (25 and 50 μg/mL) or PP2 , an Src tyrosine kinase inhibitor [μL of 1 mM p-nitrophenyl-acetyl-β-D-glucosaminide  in 0.1 M citrate buffer  and incubated at 37°C for 2 h. Then, 200 μL of 0.1 M Na2CO3/NaHCO3 solution (pH 10.0) was added to stop the reaction. Degranulation was calculated with the measurement of the released β-hexosaminidase as previously described [RBL-2H3 cells  were sensitized with 200 ng/mL of DNP-specific IgE overnight and then pretreated with PBR-BuOH (25 and 50 μg/mL) for 30 min. RBL-2H3 cells were incubated with 50 μL of Fluo-4 solution  for 30 min at 37°C and then stimulated with 200 ng/mL DNP-BSA (Ag). Images were taken every 5 min on a fluorescent microscope  using filter . Then, the fluorescence intensity was quantitated by Image J software.Intracellular calcium levels were measured as previously described , 40, 41.4 cells/well) were incubated with PBR fractions or PL fraction (25 and 50 μg/mL) at 37°C for 24 h, and then 10 μL of CCK-8 solution was added and incubated at 37°C for 2 h. The absorbance was measured with a microplate reader at 450 nm .Cell viability was determined using the Cell Counting Kit-8 (CCK-8)  as described previously , 40. RBLα was done as follows: initial denaturation at 94°C for 2 min, followed by 30 cycles of denaturation at 94°C for 20 s, annealing at 62.2°C for 10 s, and extension at 72°C for 45 s, with a final extension at 72°C for 5 min. PCR program for IL-4 was done as follows: initial denaturation at 94°C for 2 min, followed by 30 cycles of denaturation at 94°C for 20 s, annealing at 56°C for 10 s, and extension at 72°C for 25 s, with a final extension at 72°C for 5 min. PCR program for GAPDH was done as follows: initial denaturation at 94°C for 2 min, followed by 30 cycles of denaturation at 94°C for 20 s, annealing at 62°C for 10 s, and extension at 72°C for 25 s, with a final extension at 72°C for 5 min [ε receptor was performed as follows: initial denaturation at 95°C for 15 min, followed by 35 cycles of denaturation at 94°C for 30 s, annealing at 49°C for 90 s (for FcεRI α-subunit) or annealing at 51.9°C for 90 s (for FcεRI β-subunit), and extension at 72°C for 90 s, with a final extension step at 72°C for 5 min. PCR program for IFN-γ was done as follows: initial denaturation at 94°C for 2 min, followed by 30 cycles of denaturation at 94°C for 20 s, annealing at 57.3°C for 10 s, and extension at 72°C for 25 s, with a final extension at 72°C for 5 min. The following primers were used: TNF-α forward 5′-CAC CAC GCT CTT CTG TCT ACT GAA C-3′; TNF-α reverse 5′-CCG GAC TCC GTG ATG TCT AAG TAC T-3′; IL-4 forward 5′-ACC TTG CTG TCA CCC TGT TC-3′; IL-4 reverse 5′-TTG TGA GCG TGG ACT CAT TC-3′; FcεRI α-subunit forward 5′-AAT GGA TCC ACA ATG ATA GC- 3′; FcεRI α-subunit reverse 5′-AAT GAT GGG AAA ATG AGT TG-3′; FcεRI β-subunit forward 5′- GCA AAA GCT CTA CCA GAG AA-3′; FcεRI β-subunit reverse 5′-CTA CGC TCA AAT TCT TGT CC-3′; IFN-γ forward 5′-CA CAC TGC ATC TTG GCT TTG-3′; IFN-γ reverse 5′-TC CAC ATC TAT GCC ACT TGA G-3′; GAPDH forward 5′-CTT CAC CAC CAT GGA GAA GGC TG-3′; GAPDH reverse 5′-GAC CAC AGT CCA TGC CAT CAC TG-3′ . The PCR product was separated by electrophoresis in 1.5% agarose gels. The bands were analyzed by RT-PCR using LI-COR Odyssey .Reverse transcription PCR was performed as described previously , 40. Totor 5 min . PCR pro6 cells/well) were lysed in RIPA cell lysis buffer, according to the manufacturer's protocol . The protein concentrations were determined using a BCA Protein Assay kit . Equal amounts of proteins were loaded into each well and electrophoretically separated by 7–10% SDS-PAGE. The separated proteins were transferred to nitrocellulose membranes and blocked in 5% nonfat milk. Samples were probed with the following primary antibodies: phosphorylated Fyn , phosphorylated-the adaptor growth-factor-receptor-bound protein 2 (GRB2)-associated binding protein 2 , Gab2 , phosphorylated-phosphoinositide 3-kinase , phosphorylated-Syk , Syk , phosphorylated-IκBα , NFκB , phosphorylated-ERK1/2 , ERK1/2 , and β-actin . The membranes were washed in TBST  buffer  and were incubated with horseradish peroxidase-labeled secondary antibody . The bands were visualized and analyzed using LI-COR Odyssey .Protein analysis was performed as described previously , 31, 40.Six-week-old female BALB/c mice, which are housed in under specific pathogen free conditions, were obtained from Orient Bio . They were maintained in cages at 22 ± 2°C and humidity 55 ± 5% and were exposed to 12 h light/12 h darkness cycles each day. Animals were randomly divided into four groups of six mice and were acclimated to laboratory conditions for 5–7 days. They were fed with standard diet and allowed free access to drinking water. All animal experiments were approved by the Institutional Animal Care and Use Committee (IACUC) at Gachon University  (GIACUC-R2017014).μg/mL) was injected into the ear of the mice. After 24 h, mice were intravenously injected with 1 mg/mL DNP-BSA (Ag) containing 1% Evans blue dye. To measure the activity of PBR-BuOH (25 mg/kg) or cetirizine , mice were orally administered the abovementioned dosages 1 h before DNP-BSA administration. The dye was extracted from each excised ear tissue with 700 μL formamide at 63°C overnight as previously described [DNP-specific IgE 1  μg/mL waescribed . The absEar samples were fixed using 10% formalin and were embedded in paraffin as previously described . Paraffit-test and one-way ANOVA followed by Dunnett's t-test or Duncan's t-test (p < 0.05). The experimental data were analyzed using the Statistical Package for the Social Sciences-12 .Results are presented as means ± standard deviation (SD). Statistical differences between the control and the treatment groups were determined by Student's ###p < 0.001) was significantly higher than that in PL  was highest among total water extract, hexane, or ethyl acetate fractions /g of dry mass, ractions . These dβ-hexosaminidase release (an index of degranulation) in IgE/Ag-stimulated RBL-2H3 cells. As shown in β-hexosaminidase release in the PBR-BuOH-treated group was inhibited at a concentration of 41.31 ± 0.14 μg/mL . IC50 values suggested that PBR-BuOH suppressed degranulation most efficiently compared to other PBR fractions. In addition, IC50 values of PBR-BuOH treatment (41.31 ± 0.14 μg/mL) are lower than those of PL-BuOH treatment (108.07 ± 8.98 μg/mL). Thus, our data showed that PBR-BuOH significantly inhibited degranulation in IgE/Ag-stimulated RBL-2H3 cells , we evaluated whether they could inhibit H3 cells  and had s  significantly suppressed the level of IgE/Ag-induced TNF-α and IL-4 mRNA expression in a dose-dependent manner  significantly suppressed the level of IgE/Ag-induced FcεRI α-subunit and FcεRI β-subunit mRNA expression in a dose-dependent manner  and downstream molecules  are involved in FcεRI signaling pathways and NF-κB signaling pathway. First, to elucidate the mechanism of its action, we investigated whether PBR-BuOH inhibited phosphorylation of Fyn, Gab2, and PI3K. PBR-BuOH decreased the expression of phosphorylated Fyn, Gab2, and PI3K in a dose-dependent manner compared with the IgE/Ag-stimulated control , DNP-BSA (Ag) containing 1% Evans blue dye was injected through the tail vein . PBR-BuOp < 0.001) or CZ , compared with that in the IgE/Ag-stimulated control group (42.4 ± 14.9)  or CZ (20 mg/kg/day)-treated mice was decreased, compared with that in the mice with IgE/Ag-mediated PCA . The num ± 14.9) . These rPhellinus linteus grown on germinated brown rice (PBR) alleviated IgE/Ag-stimulated hypersensitivity by suppressing FcεRI-mediated pathway along with improvements in antiallergic activity. Recently, several studies reported that PBR showed enhanced biological activities, including immune regulation [α and IL-4) exerted by IgE-mediated allergy-induced basophils [In the present study, we demonstrated that gulation , anti-ingulation , 25, antgulation , 27, andgulation . The levgulation . It is rgulation  and atragulation . Other ggulation , 25. In asophils –48. In tεRI, and IgE/antigen (Ag)-complex [β-hexosaminidase [β-hexosaminidase is one of the lysosomal enzymes, which may be fused with secretory lysosome and endosome in RBL-2H3 cells [β-hexosaminidase in IgE/Ag-stimulated RBL-2H3 cells  and chemokines  are secreted by IgE/Ag-stimulated basophils and mast cells within a few hours [α and IL-4 can be used as fascinating therapeutic target molecules for IgE-mediated allergic responses [α is found in secretory granules and induces endothelial activation, adhesion molecule expression, and inflammatory cell recruitment [α [α and IL-4. We found that PBR-BuOH significantly reduced TNF-α and IL-4 mRNA expression  and the signaling portion (β- and γ-subunits). Some asthmatic patients have more FcεRI-expressed immune cells, compared with non-asthmatic control patients [εRI-expressed immune cells can rapidly respond to small amounts of IgE/antigen (Ag) complex and lead to the allergic reaction by releasing cytokines, chemokines, and other mediators, leading to activation of recruited other immune cells [εRI α-subunit-deficient mice do not induce degranulation because IgE cannot bind to the cell membrane receptor of basophils and mast cells [εRI α-subunit activates the antigen-binding site of IgE molecule, induction of FcεRI α-subunit increases IgE-mediated allergy [εRI α-subunit mRNA in IgE/antigen-stimulated RBL-2H3 cells  the translocation of granules to cell membrane  and (2) εRI , 76–79. εRI , 78, 80.H3 cells  and signH3 cells . Our obstivation , 74, 75.tivation , 41. We reaction –83. Sometivation . As showH3 cells . These din vitro results. In addition, Hong et al. conducted a clinical trial in which PBR powder was orally administered for 12 weeks to an atopic dermatitis patient at an average age of 7.3 years [PCA is a representative local type I allergy that is induced in mice by injecting IgE into the ears and intravenously injecting antigen into the tails , 85, 86..3 years . The sym.3 years .α and IL-4 mRNA expression. PBR inhibited the phosphorylation of Fyn, Gab2, and PI3K in FcεRI-mediated signaling pathway and calcium mobilization. In addition, PBR-BuOH suppressed IgE-mediated type I hypersensitivity in the PCA murine model. Our findings suggest that PBR could be developed as functional food, health supplement, and drug for treating or preventing type I allergic diseases.Our study demonstrated that PBR-BuOH has more potent antiallergy activity than PL-BuOH in IgE/Ag-mediated allergic response through suppressing degranulation and decreasing the level of TNF-


Percutaneous transfacet screw fixation (pTSF) is a minimally invasive posterior fixation technique supplementing oblique lateral interbody fusion (OLIF) for lumbar spinal disorders. Accurate screw insertion is difficult to achieve and technically demanding under 2‐D fluoroscopy. Recently developed robot‐assisted spinal surgery demonstrated a high level of accuracy of pedicle screw insertion and a low complication rate. No published study has reported this combination technique. The aim of our study was to evaluate the accuracy and safety properties of the combination of both minimally invasive techniques: robot‐assisted pTSF supplementing the OLIF procedure.This was an experimental and prospective study. Selected consecutive patients with lumbar degenerative disorders received robot‐assisted pTSF supplementing the OLIF procedure using the TianJi Robot system operated by one senior surgeon from March to October 2018. The accuracy of screw insertion and perioperative screw‐related complications were evaluated. Assessment of the accuracy of screw insertion included intraoperative robotic guidance accuracy and incidence of screw encroachments. Intraoperative robotic guidance accuracy referred to translational and angular deviations of screws, which were assessed by comparing the planned and actual screw trajectories guided by the robot on reconstructed images using TianJi Robot Planning Software. Screw encroachments were evaluated on postoperative CT images and classified by a grading system . Screw‐related complications including intraoperative pin skidding, screw malposition and adjustment, together with postoperative neurological symptoms that correlated with screw malposition were recorded.4–5 level and three segments at L3–4 level. Two patients had both L4–5 and L3–4 level fixation. The average surgical time was 3.3 h . The mean blood loss was 90 mL . Intraoperative guidance accuracy showed 1.09 ± 0.17 mm (ranging from 0.75 to 1.22 mm) translational deviation and 2.17° ± 0.39° (ranging from 1.47° to 2.54°) angular deviation. The gradings of screw encroachment were: 17 screws (71%) with Grade A, 6 screws (25%) with Grade B, and 1 screw (4%) with Grade C. Only one pin skidding occurred intraoperatively and revised subsequently. No postoperative neurological complications were found.Ten patients, with an average age of 60.2 years, were selected and recruited in this study. All cases were degenerative lumbar spinal disorders, out of which there were 6 cases of Meyerding Grade I degenerative spondylolisthesis. Twenty‐four transfacet screws were inserted by robotic assistance. Instrumented levels included nine segments at LOur preliminary study of robot‐assisted pTSF supplementing the OLIF procedure showed a high level of accuracy for screw insertion and this minimally invasive combination technique was found to be a feasible and safe procedure. Oblique lateral interbody fusion (OLIF) is a recently developed minimally invasive surgical technique for degenerative lumbar disorders. It offers several advantages, including less bleedingThe conventional pTSF were performed under 2‐D fluoroscopyBecause precise pTSF insertion technique is demanded and the robot‐assisted surgery could provide a high level of accuracy, pTSF could be accurately performed with the assistance of robot. Theoretically, the combination of OLIF and robot‐assisted pTSF could be safely and accurately performed as a minimally invasive procedure. To our knowledge, however, robot‐assisted pTSF has not been described in the literature. We attempted to assess the safety and accuracy of this technique in a prospective and experimental study in Beijing Jishuitan Hospital. Several orthopaedic robots have been reported to be applicable for spinal procedures, including TianJi Robot, SpineAssist, Renaissance, and Mazor. SpineAssist and Renaissance, the early products of orthopaedic robots, are “bone‐mounted” machines that need temporary fixation onto the spine of interest, and synchronization of a preoperative CT scan and intraoperative fluoroscopy which is often time‐consuming is used for image registration. The TianJi Robot is an orthopaedic surgical robot developed in China with completely independent intellectual property with multiple surgical indications and wide applications for the whole spineThe aim of our preliminary study was to evaluate the safety and accuracy of robot‐assisted pTSF combined with the OLIF procedure. Both the OLIF technique and pTSF are muscle‐sparing procedures involving tiny surgical incisions. If the robot‐assisted surgery could permit a safe procedure, as a minimally invasive method, the combination method could decrease the surgical trauma to patients, with less blood loss and approach‐related musculature disruption. Therefore, it could allow for faster recovery and better patient‐reported quality of life. Compared with conventional pedicle screw fixation, pTSF only needs two cannulated screws for each segment, which are much less expensive than pedicle screws and would mean less cost for patients and society. Radiation exposure is an issue of concern during orthopaedic surgery. Conventional screw insertion is usually performed under fluoroscopy and there is a constant need for images during surgery. Robot‐assisted surgery allows for perioperative planning and single imaging may decrease the amount of radiation exposure for both patients and surgeonsSelected consecutive patients were prospectively studied from March 2018 to October 2018 in Beijing Jishuitan Hospital. Patients with degenerative lumbar spine disorders, suffering from incapacitating back or radiating pain which could not be relieved by conservative treatment for more than 3 months, were included in this study. The exclusional criteria were Meyerding II degenerative spondylolisthesis or above, lumbar instability caused by neoplasm, infection or trauma, severe facet joint arthropathy, multi‐level lumbar spinal fusion, and spondylotic spondylolisthesis. Patients with neurological symptoms that could not be partially relieved by resting on a bed were also excluded. Informed consent was obtained preoperatively for the selected patients. These surgeries were performed by a senior spine surgeon  who had the experience of more than 50 robot‐assisted spinal surgeries.The TianJi Robot  is not a “bone‐mounted” robot but an image‐navigated robotic positioning platform, which comprises a robotic arm system, an optical tracking system, and a robotic workstation (including the monitor screen). During the procedure, images obtained intraoperatively by C‐arm are transferred into the robotic workstation and 3‐D images are created. Surgeons’ planning of the screw trajectories is performed on the robotic workstation. Afterwards, the robotic arm with a guidance cannula on its end automatically moves to the surgical field and guides the pin insertion within the cannula of variable inner diameter. A fluoroscopic re‐scan by C‐arm is performed and followed by cannulated or conventional screw placements if the optimal pin trajectories are confirmed Fig. .The patient was placed at a right decubitus position on a radiolucent table. Oblique skin incision was marked within the range of 4 to 10 cm anterior to the disc or vertebral body of interest under fluoroscopic guidance. After prepping and draping, the skin and superficial layer were incised, followed by blunt dissection of abdominal muscle. The interval between the psoas major and the aorta was bluntly dissected using fingers. Afterwards, the cannulated corridor was established at the level of intervertebral space. The intervertebral disc was removed and both endplates were prepared for cage insertion. Subsequently, the cage  of appropriate size containing allograft was inserted and the optimal position was confirmed by fluoroscopy.The patient was positioned in a prone position after completing the OLIF procedure. The surgical field was prepped and draped. A 2‐cm small midline incision was utilized for anchoring a patient tracker onto the spinous process. The patient tracker was necessary for navigational purposes. An alternative method for patient tracker fixation is sticking the tracker onto the skin surface using several sterile drapes. Fluoroscopic images were obtained by C‐arm  and transferred to the robotic workstation. 3‐D reconstructed images were generated and displayed on the monitor screen.The senior surgeon planned the optimal trajectory of transfacet screws on the workstation Fig. . The entAfter finishing the planning of transfacet screws, the robotic arm was instructed to move to the surgical field. The guiding cannula was placed onto the robotic arm and approached the skin closely. The accuracy of guidance was shown on the monitor screen. Once the accuracy of guidance was less than 0.5 mm and became steady, the robot was ready to guide the pin insertion. A tiny incision was made. The guiding pin held by a drilling bit was placed along the guiding cannula at the end of the robotic arm. The pin was advanced until the bony surface was touched. The guiding pin was gently drilled to optimal depth usually 30 mm). See Fig. 0 mm. SeeA fluoroscopic re‐scan by C‐arm was performed and the position of guiding pins was evaluated. If there is any deviation of the guiding pin, the trajectory should be revised. If the optimal position of the guiding pin was confirmed, the pilot hole was tapped, followed by insertion of cannulated Herbert screws . Afterwards, the positions of transfacet screws were evaluated and confirmed under fluoroscopy. See Fig. The accuracy of screw insertion was evaluated, which included intraoperative robotic guidance accuracy and grading of screw encroachment.Step 1: Image fusions. Using TianJi Robot Spine Software to fuse planned CBCT and K‐wire placement CBCT into a single image.Step 2: Entry and target point recognition. Identify the entry and target point of the planned screw trajectory and K‐wire placement, respectively.Step 3: Calculate the deviation between planned trajectory and K‐wire placement. Euclidean distance was used to calculate the displacement deviations.Step 4: Measure the angular deviations in the axial and sagittal plane, respectively. Calculate the average value of both angular deviations in the dual planes.Robotic guidance accuracy refers to the degree of translational and angular deviations during the robotic guiding process. Measurements were used to compare the planned and actual trajectories on reconstructed images obtained by C‐arm . To enable a comparison in the same plane, CBCT‐to‐CBCT overlay software (TianJi Robot Planning Software) was used to fuse each patient's two 3‐D fluoroscopic scans. Methods of measurements are listed below and illustrated on Fig. Postoperative screw encroachment of the cortex was evaluated on the postoperative CT scans. Positions of screws were qualified and graded Fig. . Grade AThe intraoperative and recent postoperative complications related to screw malposition were recorded. The intraoperative complications include technical issues, such as hardwire failure and K‐wire skidding causing screw misplacements. Postoperative complications include neurological compromise, such as radiating pain, numbness, and decreased muscle power, which correlate with screw malposition. Other early postoperative complications irrelevant to screw malposition were also recorded.The quantitative and qualitative data was collected and analyzed using Microsoft Excel (Version 16.16).4–5 instrumentation and fusion. Detailed information for each case is shown on Table Ten patients were prospectively studied, out of which 3 were men and 7 women. The average age was 60.2 years . All cases were degenerative lumbar spinal disorders, out of which there were 6 cases of Meyerding Grade I degenerative spondylolisthesis and 4 cases of lumbar segmental instability and lumbar stenosis. One patient had previous L4–5 level and three segments at L3–4 level. Two patients had both L4–5 and L3–4 level fixation. Twenty‐four transfacet screws were inserted. Ten screws were inserted as translaminar transfacet screws, while the others were transfacet screws. The average surgical time was 3.3 h . The mean blood loss was 90 mL .Instrumented levels included nine segments at LThe average displacement and angular deviations of these 24 screws were 1.09 ± 0.17 mm (ranging from 0.75 to 1.22 mm) and 2.17° ± 0.39° (ranging from 1.47° to 2.54°), respectively. The gradings of screw encroachment were 17 screws (71%) of Grade A, 6 screws (25%) of Grade B, and 1 screw (4%) of Grade C.During the procedure, only 1 case had K‐wire skidding in the drilling holes at the cortex and the trajectory was revised after the fluoroscopic confirmation. No screw misplacement was noticed during the procedure. Five patients had numbness over the anterior thigh and iliopsoas muscle weakness, which subsided within 2 weeks. No complications were found to be correlated with the screw malposition.The oblique lateral approach is a muscle‐sparing route for cage insertion and the cages used in the OLIF procedure are larger than the counterparts used in the TLIF procedure, which could improve the lumbar alignment to a greater extentPosterior fixation is typically required in OLIF procedures to reinforce the segmental stability. As one stability supplement method, pTSF has several advantages compared with open TLIF surgeries: there are few incisions, there is minimal blood loss, and only two screws are used each spinal segment, which are less expensive than pedicle screws for. In our study, only one tiny incision was needed for pTSF in several selected patients and each case only had 90 mL of blood loss on average. Those findings suggest that this combination technique is a promising minimally invasive procedure.et al. report a cadaveric study showing the same stiffness between pTSF and PSF techniques in the short‐term phase and the long‐term cyclic loading phaseet al. even shows that pTSF has greater stability than pedicle screws in motion of flexionTransfacet screw fixation in the lumbar spine was described by Kinget al. performed a retrospective study evaluating the accuracy, hardware failure, and complications of pTSF in ALIF and lateral lumbar interbody fusion (LLIF)et al. evaluated the long‐term results of LLIF supplemented with pTSFThe clinical results of pTSF as a minimally invasive posterior fixation technique are examined in several published studies and promising results are reported in the literatureet al. reported that the perforation rate of the transfacet screw was 34%et al. reported the clinical results of fluoroscopy‐assisted transfacet screw insertion2‐D fluoroscopic guidance is the method most commonly used to assist in transfacet screw insertionet al. found that the breach incidence of pedicle screws was lower in the robot‐assisted group and breaches only occurred in the lateral direction, compared with medial or inferior breaches in free‐hand groupRobot‐assisted spinal surgery showed high accuracy of screw placement: 92.9% to 100% accuracy of pedicle screws was reported using Gertzbein and Robbins criteria in analyzing screw placement accuracyWith respect to the safety of this technique, intraoperative and early postoperative complications of robot‐assisted pTSF were evaluated in our study. Only 1 case had K‐wire skidding, which was revised afterwards. Early postoperative complications showed that 5 cases had OLIF approach‐related complications, including numbness over the anterior thigh and iliopsoas weakness. No complications were found to correlate with screw malposition. These results demonstrate that this technique is a safe procedure.Pin skidding during drilling and the insertion process was the most common intraoperative complication in percutaneous robot‐assisted proceduresThere are several limitations of our study. The sample size of patients was small in this preliminary study and the number of cases would be increased in our future study. In future study, the mid‐term and long‐term clinical results of this technique will be evaluated during the patients’ follow‐up.


Most parametrizations of wave propagation in sea ice assume without question that the frequency-dependent attenuation which is observed to occur with distance x travelled is exponential, i.e. A = A0 eαx−. This is the solution of the simple first-order linear ordinary differential equation dA/dx = − αA, which follows from an Airy wave mode ansatz A/dx = − αAn is proposed to allow for a broader range of attenuation behaviours should this be necessary to fit data.Because of their capacity to alter floe size distribution and concentration and consequently to influence atmosphere-ocean fluxes, there is a compelling justification and demand to include waves in ice/ocean models and earth system models. Similarly, global wave forecasting models like WAVEWATCH IIIThis article is part of the theme issue ‘Modelling of sea-ice phenomena’. Indeed, reviews ,2 includin situ, remote sensing has also provided valuable datasets using both satellites and aircraft missions. Whether focused upon continuous pack ice, the loosely compacted ice floes of the MIZ, or pancake ice, nilas, frazil and grease ice, the compilation of research papers and reports is impressive and continues to grow as the contemporary importance of the subject is recognized and technological advances make practicable more sophisticated measurements that were not feasible 20 years ago.As well as observations collected Ocean waves propagating in an ice field are observed to decrease in amplitude. The observed reduction is due to a combination of two processes—scattering and dissipation, which both need to be accommodated in any earth system model, ice/ocean model or wave forecasting parametrization. Scattering redistributes energy but does not eliminate it while dissipation, insofar as the waves are concerned, removes energy. Undoubtedly, the latter process actually reassigns the energy to other parts of the atmosphere/ice/water system, e.g. to kinetic energy in the mixed layer, etc., and this will be important in earth system models which are required to conserve energy because they compute results over very long time scales. However, this prerequisite is not important here, as the system under consideration is not closed.® (hereinafter WW3) where ocean currents are included [E = E,x denotes the spatial coordinates, ω is the radian frequency , θ is the direction of travel of the wave, the group velocity cg is taken as constant and Sin represents wind–wave interaction, Snl is a nonlinear wave–wave interaction term, Sds is a dissipation (whitecapping) term and Sice = Sice is the term of interest in this work as it characterizes how the waves are affected by the ice field. Sice can be partitioned into the two processes introduced above, which are, respectively, designated energy attenuation coefficients αscat and αdis,αdis = 0.The energy transport equation, or the wave action equation in WAVEWATCH IIIincluded , is usedαscat and αdis as energy attenuation coefficients, in keeping with [α to denote the amplitude attenuation coefficient later, recognizing that for exponential attenuation αscat (and αdis) ∼2α.The author has specifically referred to ing with . For claαscat in the MIZ, e.g. the phase-resolving, two-dimensional scattering theory described in [αscat is well understood and adequately modelled. This is important because contemporary phase-resolving scattering models provide a direct link to ice floe break-up and hence to how the floe size distribution changes, as flexural stresses in the compliant ice floes that make up the MIZ are easily calculated [K(θ − θ′) in equation  and attenuation (via imaginary iα) into one consolidated complex wavenumber. Typically, a boundary value problem is then solved, e.g. for open water surface gravity waves travelling into an homogeneous plate or layer which can be semi-infinite or finite in horizonal extent and has prescribed physical properties that define its behaviour in flexure. As a rule, the ice would be designated as elastic, viscous or viscoelastic; each being reasonable when the wave amplitudes are modest for the strain rates induced by typical surface waves in the sea ice under various circumstances. The material properties chosen for the ice provide the dispersion relation that regulates how the waves propagate under the ice cover, i.e. how they disperse and reduce in amplitude, and, because the wavenumbers in open water and ice-covered sea are different, the impedance change at the ice edge which causes some of the wave energy to be reflected. Weakly nonlinear formulations exist but they are relatively rare, e.g. [The above comments notwithstanding, it is conspicuous that the vast bulk of theoretical models constructed to describe how waves are affected by sea ice or vice versa, are configured to fit a linear paradigm, i.e. they employ an Airy wave mode ansatz  of the fre, e.g. .a priori adherence to the linear A = A0 eαx− prototype can be problematical when (i) parametrizing in operational forecasting systems and earth system models, as it predisposes the attenuation to be exponential; (ii) attempting to fit any such model to data, because the exponential function A = A0 eαx− may have too few degrees-of-freedom to fit the data at all the spectral wave frequencies present. Moreover, (ii) may contribute to enigmatic intermittent features that have been seen in some field datasets, e.g. [The author is not dismissing linear models that describe wave propagation into and within ice fields. With graduate students and colleagues, I have constructed no end of linear, physically based models, e.g. ,6,8,9, ots, e.g. , acknowlts, e.g. .2.(a)in situ experiments can be done to ascertain whether the model is a good fit to data. It is these attributes that are symptomatic of a paradigm I model.A crucial distinction needs to be made between two classes of theoretical model, designated paradigms I and II herein. Papers ,6,8,9 arμ altered to have a complex flexural rigidity so as to produce damping, being used to model an entire, potentially open, i.e. of low-concentration, heterogeneous ice field.  Parameexamples ,6,8,9,15μ and [The computed model parameters also strictly have no material physical interpretation as they are only associated with the experimental data being analysed, so generalization to other ice fields or ocean wave states is challenging or impossible. Moreover, it must be asked how faithful the model is to the physics of the process being observed and whether it is actually capable of replicating observations. The author contends that this has not been convincingly demonstrated to date. Indeed, there are incontestable analyses that suggest that μ and [15μ and .xA = − αA with solution A = A0 eαx−, is unlikely to be a reliable approximation to Nature in all circumstances and the issue of poor adherence to observed α(ω) behaviour at high frequencies is becoming clear. (Here and subsequently the abbreviation dx≡d/dx is used.)Without knowing that they are a universally valid parametrization, some prototype models are already being embedded within operational wave forecasting systems such as WW3 and earth system models that operate under a very diverse range of environmental circumstances, e.g. for large wave steepnesses where the differential equation predicting attenuation, namely dk = κ + iα. An alternative differential equation, namely dxA = − αAn, derived using physical arguments for pancake ice in [n, will also be presented as a generalization of the archtypal exponential attenuation law A = A0 eαx−. Remarkably, the model in [A changes from its value A0 at the ice edge as the wave advances through the ice medium, namelyn and α are to be found, is a generalized decay law that reverts to one with a constant rate of decay when n = 0 and exponential decay when n = 1 [ω, in a particular way and derives from a power law fluid constitutive relation. Rather than just ‘best fit’ observations, I will also describe how the value of n can be predetermined to some extent by aggregating intelligence about the nature of wave–ice interaction in MIZs.Although the purpose of this paper is not to review the field of wave–ice interactions, it would be remiss of me not to corroborate the assertions I have made as best I can. This will be done in later sections. Subsequently, using data from a recent field experiment, I will focus on the constraints implicit in linear models that conflate dispersion and attenuation in ice fields using the single complex wavenumber e ice in  and potemodel in  affords model in . While ten n = 1 ,18. The n = 1, I reiterate that ice fields are never homogeneous. Accordingly, it is highly unlikely that any parsimonious decay equation will replicate the behaviour of ocean waves travelling in sea ice perfectly, because the attenuation experienced depends on the local oceanographic and ice properties as reported in [n may help but, recognizing the immense challenge of conducting wave experiments in sea ice, the importance of comprehensive sea ice morphology and oceanographic observations collected simultaneously to complement the wave data cannot be overstated if we are serious about calibrating an aspiring parametrization.Irrespective of the simplicity of orted in  for the (b)ω with k. The dispersion relations, ω = ω(k), are distinct in each case and for different models but the dependency of the amplitude A on x that follows is always exponential.I briefly discuss the three most common material descriptions used to categorize sea ice when it is subjected to ocean wave forcing; elastic, viscous and viscoelastic. The common theme is (i) linearization about the basic state of rest, (ii) assuming the motion is proportional to k is real when the ice is uniform and purely elastic if no further dissipation, arising from a combination of ice flexing, dissipation in the water and mechanical energy loss such as collisions between ice floes or cakes, is parametrized. Waves disperse differently under solid ice compared with open sea and also attenuate due to scattering. This is because the ice-coupled wavenumber depends on the physical properties of the sea ice so transitions of ice morphology, e.g. thickness, or the edges of ice floes cause reflections to occur. However, this process represents a redistribution of energy as opposed to dissipation. In the context of this paper, this means that a perfectly elastic sea ice cover can only reduce wave amplitude if the ice is not spatially uniform.The generic ice wavenumber A number of papers represent the entire sea ice cover as a viscous layer at the ocean surface, e.g.  models wω = ω(k) results that, as usual, is constructed by first assuming the Airy wave mode ansatz κ = Re k expressing dispersion and α = Im k expressing attenuation via A = A0 eαx− so any nonlinearity is neglected a priori.In fact, sea ice itself is viscoelastic, with different degrees of nonlinearity dependent on its physical properties and environmental circumstances. At ocean wave forcing frequencies, first-year sea ice itself is approximately anelastic , i.e. anc are treated by reducing the effective medium's response linearly. At first sight this seems reasonable but, when it is recognized that most of the dissipation arises because of turbulence in the water, it becomes counterintuitive. Surely the level of dissipation would increase initially with a reduction in c, as ice floes become more mobile and ‘belligerent’, and then start to decrease as c → 0 as the effects of floe collisions, waves breaking over floes and overwashing subside.It is also noteworthy that variations in concentration α(ω)∝ω2–ω3 in many circumstances, yet Meylan et al. [μ and [ω7/2 when dispersion is assumed to be the same as in open water. The closest to ω2–ω3 to date is the model in [α(ω)∝ω3. It has simple velocity-dependent damping incorporated in the elastic plate model [μ.Observations suggest that n et al.  show, afn et al. μ and [16. [μ and  is so co. [μ and –24 go asmodel in , for white model  as an alte model μ.α plotted as a function of wave frequency f from 403 wave buoy spectra collected during a 2015 field experiment in the Beaufort Sea carried out from the ship R/V Sikuliaq in a mixture of pancake ice and frazil. Results are clustered into three coloured sub-groups representing experiments where dissipation was high (red), medium (cyan) and low (green). When no usable ice observations are available the experiment's α are shown in black. Using an inversion process to provide physical moduli, these data are compared with the viscoelastic layer model [α(ω)∝ω7 behaviour contributes to the observed steepness. A more general equation describing attenuation such as dxA = − αAn could possibly help, as we shall find that it allows viscosity to be functionally dependent on frequency as opposed to being constant xA = − αAn was first applied to sea ice back in 1973 [n = 3. In its general form the equation requires that the viscosity of the deforming material μ is not constant, as it would be for Newtonian flow, but that it depends on strain rate. When n = 3, μ( · ) is inversely proportional to the square of σd)∝τn) increases with increasing strain rate and it is said to be dilatant or shear thickening; when n = 1,  μ = const.; and when 1 < n < ∞, μ( · ) decreases as strain rate increases and the material is described as pseudo-plastic or shear thinning. Because shorter period waves reduce in amplitude more rapidly than longer ones in sea ice, i.e. attenuation increases as frequency and strain rate increase, the phenomenon of wave–ice interaction is dilatant. This does not, however, necessarily mean that sea ice is a dilatant material; indeed at very long time scales it would be expected to behave similarly to fresh water glacial ice and to be pseudo-plastic. To the author's knowledge, the power law fluid has not been considered as a viable constitutive relation for sea ice itself.Power-law fluids have a strain-rate-dependent apparent viscosity n = 0, where viscosity μ increases at a uniform rate with τ, which in the present context leads to the imperative of wave trains reducing in amplitude in direct proportion to the distance they travel and, axiomatically, the complete elimination of wave energy over a finite distance; (ii) μ increases uniformly with n = 1, where μ = const. and an exponential decay law holds. Of course, n can take on other values that determine whether the attenuation is less or more rapid than exponential over a finite domain. Recognize that in a power law fluid n≥0, as stated. This is not necessary for equation  equation , where n(b)μg2k4 = 2ω(ω2 − gk)2 and furnish an α(ω)∝ω7/2 for a very thin viscous layer overlying an ocean of much lower viscosity (see equations (4.14) and (4.15) of [μ( · ) be adjusted such that the order of these viscous models is reduced from ω7/2 to ω2 by choosing n such that the excessive dilatancy is eliminated to give a beneficial μ(ω)?’. It is conjectured that n = − 2 achieves this goal, ultimately producing α(ω)∝ω2 from that predicted by the dispersion relation.In §4.15) of ). While A0(f) evolves with distance x, again assuming that α(f)∝f2 and recalling that ω = 2πf. A0(f) is derived from the quintessential Pierson–Moskowitz energy density spectrum E0 = E0(f) at the ice edge, by integrating across a comb of frequency bands and then taking the square root. What we are calling an RMS amplitude spectrum is, therefore, the square root of a spectrum composed of a set of contiguous bandlimited energy density integrations. Although A0(f) depends on bandwidth, this is unimportant here as all calculations are relative rather than absolute. The Pierson–Moskowitz spectrum E0, see figure 2a, has the formfp is the peak frequency which is set to 0.1 Hz to be consistent with [g is the acceleration due to gravity and the numerical constant 8.1 × 10−3 is known as the Phillips constant [A0 directly or by numerical integration. The two sets of amplitude spectra, coloured green, magenta and yellow in figure 2b,c, shows the frequency-dependent attenuation experienced by the A0(f) spectrum as it advances into the notional ice cover, which either (figure 2b) attenuates exponentially with penetration x, or (figure 2c) in direct proportion to x. It is evident that the latter decay (figure 2c) is much greater for the same constant of proportionality in α∝f2. Although artificial, it does demonstrate the potential of the more general behaviour furnished by dxA = − αAn, which may be especially useful for parametrizing dissipation caused by the aggregation of nonlinear processes that expunge energy from incoming wave trains for the first 10 or so kilometres from the ice edge or, in all likelihood, farther when wave amplitudes are large  has an f−4 tail above f = 0.1 Hz, i.e. E0(f)∝f−4⇒A0(f)∝f−2. (The Pierson–Moskowitz spectrum has an f−5 tail and we have confirmed that the A0(f) spectrum in figure 2b,c has an f−5/2 tail, as required.) Seek a model that has an α(f)∝f2 form irrespective of the value of n, interpreting α throughout equivalently. Three examples are considered, the first of which is somewhat artificial, as follows.f−4 tail in the spectrum doesn't change as the wave field from which it is constituted propagates farther into the sea ice cover. Using equation /x.(i) Suppose that the equation , it is sn = 1. In this case, amplitude (ii) Exponential attenuation is recovered when n = 0, A = A0 − αx∝f−2(1 − c2f4x).(iii) For Finally, let us consider some real data and arbitrarily adopt the solid red curve in fig. 6 of , which sc1 and c2 are constants that arise from the proportionalities assumed, i.e. in the tail of the incident energy density spectrum, where E0(f)∝f−4 and α(f)∝f2. Although A0 initially reduces in direct proportion to distance x when n = 1, the decrease with x is greater for the n = 0 example if the magnitudes of α are numerically similar .In the above (c)Sikuliaq field programme produces an analogous conclusion for pancake ice [x but in direct proportion to x when they exceed 3 m. However, respecting the comments I made earlier about ice field heterogeneity, it is acknowledged that it is also possible for these data that this effect is due to the sea ice being more broken up when the waves are higher.Based upon observations transmitted to satellite by some floating wave buoys, it is reported that the significant wave height of modest incident seas diminishes exponentially in the Southern Ocean MIZ , but thacake ice , specifia priori assumption of exponential decay across pairs of stations using the Airy wave mode ansatz introduced earlier. As a consequence, it is of interest to establish whether a similar kind of attenuation occurred during the 2015 R/V Sikuliaq field programme, where wave amplitudes were often quite large during one of the experiments. This accords with our original conjecture in §n≤1 value extracted from a direct best fit of the SWIFT buoy data [figure 3a, median n is plotted against the mean value of frequency in figure 3b and the percentage of n = 0 attenuation profiles as a function of energy density is plotted in figure 3c.  It is unfeasible to use a paradigm I model in a global scale earth system model or WW3.(ii) Ocean waves travelling in sea ice reduce in amplitude due to two phenomena: conservative scattering by ice floes, which relocates energy; and true dissipation, arising from several poorly quantified nonlinear phenomena that remove energy.(iii) Dissipation is most extreme near the ice edge and/or when the waves are most fierce but the width of the zone over which it dominates other sources of attenuation will vary with the wave and ice conditions.(iv) Scattering is most significant when floe diameters and wavelengths are of the same order, while dissipation is always present to a greater or lesser degree depending on the properties of the sea ice and the waves.Sice, defined in equation  Although the energy transport equation's source/sink term equation , separat(vi) Ocean waves break up ice floes to create the floe size distribution, an important process that is modelled by scattering theory, taking into account the flexural stresses in the floes provoked by wave-induced bending .(vii) Nearly, all contemporary models constructed to characterize wave propagation into and beneath sea ice in its several forms are linear including those associated with paradigm II, with some having been reapplied to represent ‘effective media’ in circumstances that they were not originally intended to model.(viii) The fidelity of current effective media models in the MIZ has not yet been demonstrated.(ix) Material constants in effective media have no physical meaning, as to make its predictions the medium aggregates a smorgasbord of disparate mechanisms and calibration is unattainable because of the unique set of conditions that define each experiment.α(ω)∝ωp, 2≤p≤3, with some experiments suggesting p = 2, yet contemporary paradigm II parametrizations do not easily reproduce this asymptotic behaviour.(x) Conceding the scattered nature of the field data, it appears that the attenuation coefficient (xi) Primarily because of dissipation, there is reasonable observational evidence to conclude that attenuation is not always exponential and a natural consequence of this is that waves may experience different ‘attenuation laws’, during their passage through ice fields.(xii) Because of nonlinearity, exponential attenuation appears to be associated with waves of low amplitude while more substantial waves may experience other kinds of damping, e.g. proportionate to the distance they travel.(xiii) While at first sight scaling material constants in parametrizations in proportion to concentration is physically plausible, it may actually not be an effective universal stratagem because of the substantial damping that can occur in the water between ice floes.xA =  − αAn with solution An)(1− = An)(1−0 − (1 − n)αx, or its equivalent energy density form with a different value for n≠1, may be helpful as a simple yet more general parametrization of wave attenuation in pancake ice that includes both scattering and dissipation.(xiv) Acknowledging that, as always, calibration will be challenging, the equation dThe most significant opinions expressed in this paper are drawn together as a useful resource.


Cement augmentation is a technique used to increase the stability and purchase of pedicle screws in poor quality bone. Various methods can be applied for cement delivery, such as cement injection before screw placement and the use of fenestrated screws. However, potential problems can arise with the use of cement augmentation.2‐5), with minimal comorbidities, was referred to our unit 9 months after surgery. Pain and progressive kyphosis were investigated clinically and radiographically with computed tomography (CT) scans to assess the status of the hardware and fusion. CT imaging revealed that cement was present only at the distal tip of the fenestrated screws at the L4 vertebral level. A non‐union was present along with loosening and a halo around the body of the pedicle screws, and there was evidence of pullout of inferior screws.A 66‐year‐old man with a lower trunk deformity, severe kyphosis, and sagittal imbalance following fusion (LSingle‐level cement augmentation of pedicle screw in a posterior construct and distal tip cement augmentation of the screw results in a fixed pivot point. Micromotion in cranio‐caudal loading during flexion and extension may result in screw toggling with the single‐level cement‐augmented tip as a fulcrum. This may cause screw loosening, which can lead to pullout and loss of construct stability. The halo around the screw suggests bone loss and/or a fibrous tissue interface, which further complicates revision surgery. Stress shielding and polymethylmethacrylate cement present additional difficulties.The findings of this technical note question the risks and benefits of cement‐augmented fenestrated pedicle screw fixation for spinal fusion. Although incidences of such cases are uncommon, surgeons should perform this technique with caution. Accurate restoration of lumbar lordosis during index procedures is important to minimize the risk of construct failure. The use of vertebral screws for spinal fixation dates back to the 1940s and has since evolved into pedicle screw fixation for stabilization to encourage intervertebral arthrodesisHowever, potential problems can arise with cement augmentation. Intraoperative mis‐positioning of screw holesAlthough clinical studies discussing the potential toggling of pedicle screws have been carried out, to the authors’ knowledge there is no formal publication reporting the outcomes of screw toggling in patients. This technical note will discuss the outcomes of distal cement augmented pedicle screw which serves as a pivot point for proximal screw toggling and loosening.2‐L5) with postero‐lateral grafting, without inter‐body implants from a different institute. He experienced significant pain due to L4 and L5 motor / sensory radiculopathy. Reflexes were absent in both lower limbs with a bilateral foot drop. Oswestry Disability Index was 74%, with Visual Analog Scale pain score of 10 in the standing position, 8 on lying flat.We report a case of a 66‐year‐old male with minimal co‐morbidities who presents with lower trunk flat back deformity, severe iatrogenic kyphosis and sagittal imbalance following 9 months postoperative lumbar decompression and fusion  scan revealed loosening and non‐union of the inferior aspect of the fusion construct. There is pull‐out of the inferior screws Fig. A with haThe haloing effect demonstrated by the pedicle screws is consistent with hardware failure, and also seen in the “PEEK‐Halo” effect when PolyEther‐Ether‐Ketone (PEEK) is being used as an intervertebral implant which results in poor osseointegration3/4 and L4/5 levels) and Posterior Smith‐Peterson osteotomy at L3/4. Focal lordosis of approximately 22o was corrected resulting in a total correction of over 65 degrees at L3/4. The patient was able to stand up‐right which enabled him to maintain his view on horizon when his spine was in a neutral position. Figure A revision procedure utilizing both anterior and posterior approach was carried out Fig. . LordosiTo the authors’ knowledge, there is currently no literature reporting such an adverse event, however the use of fenestrated cement fixation is relatively recent. A cadaveric study by Bostelmann et al. studying the effect of cranio‐caudal cyclic loading on non‐augmented and cement‐augmented pedicle screws concluded the superiority of augmentation compared to standard pedicle screwsIn the case of fenestrated screws were only the tip is strongly fixated by cement in the vertebral body, the tip can act as a fulcrum in which micro‐movements and torsion can cause toggling of the screw body within the pedicle, resulting in proximal loosening, and non‐union of the fusion construct. As time passes, cranio‐caudal loading during lumbar flexion and extension, accumulates into a significant amount of force which eventually results in minute motions turning into significant toggling upon the cemented fulcrum. Further loading result in more proximal toggling. The loss of bone structure around the screw appears as a haloing effect seen on imaging Fig. . The togThe reduced forces withstood by the spine may be a potential risk factor for stress shielding to occur. As seen in the hip, stress reduction in an implanted bone can lead to bone lossThe end result of such an effect can be disastrous to the patient. Revision of the loose pedicle screws presents a significant problem, as removal of these screws may lead to further damage of the surrounding bone or fracture of the vertebral body and the pedicles. The patient may require further levels of fusion as well as other invasive surgeries  to correct the kyphosis. Blattert et al. argued that removal of cement‐augmented fenestrated screws was possible even in severe osteoporosis. They concluded that the cement screw connection was fragile enough to break off during extractionDifferent methods have been proposed and used for the revision of non‐augmented pedicle screws. These include the use of a larger and longer pedicle screwsIn addition to extending the posterior construct for re‐establishing sagittal balance, the authors agree that the use of interbody fusion techniques may further benefit the patient for anterior column support. In terms of correcting sagittal alignment, the use of ALIF as in the current case has been shown to compliment other realignment techniquesFurther studies and data are required to study the long‐term efficacy of cement‐augmented pedicle screw fixation, associated risks and complications. Long‐term outcomes of pedicle screw fixation comparing different screws should be carried out to compare the pros and cons of different screw designs. Recently, expandable pedicle screws have gained an interest amongst spine surgeonsThe use of single‐level cement augmentation has resulted in a fulcrum for screw toggling when load was applied along the construct. Accurate restoration of sagittal alignment with ideal lumbar lordosis at the index procedure while using cement augmentation techniques would have reduced the risk of such a complication. Separately, the use of cement‐augmented fenestrated pedicle screws is a recent technique. Although there is currently an adequate body of literature on the pull‐out strength and stability of cement‐augmented fenestrated pedicle screws, there are no reports on non‐union biomechanics and the effect of cranio‐caudal toggling. Haloing around pedicle screw due to toggling is a major complication especially if cement‐augmentation was used. This phenomenon adds significant difficulty and potential morbidity to the revision procedure. Anterior or lateral interbody cages may aid with sagittal realignment. The appearance of such phenomenon potentially questions the role of such fixation technique. The use of intra‐operative on table CT scan may be beneficial to access the accuracy of screw placement in order to limit post‐operative toggling due to abnormal stress loading.All authors contributed significantly and met the authorship criteria according to the latest guidelines of the International Committee of Medical Journal Editors. All authors agree to the final submitted manuscript.


BackgroundPedicle screw fixation is currently the mainstay technique for lumbar spinal fusion; however, more minimally invasive techniques are available such as cortical screw fixation. Numerous studies have proven biomechanical equivalence or superiority for cortical screws but few studies have examined clinical outcomes in patients. Our study aims to examine functional outcomes, as well as fusion rates, in patients who underwent pedicle screw fixation using a cortical trajectory.MethodsWe retrospectively reviewed prospectively collected functional outcomes data on 10 patients with a degenerative lumbar disease who underwent cortical screw placement by the senior author. Oswestry Disability Index (ODI) and Roland Morris (RM) scoring were calculated preoperatively, at six to 12 weeks and at six to eight months. The Kruskal-Wallis test and Dunn’s multiple comparison were used to analyze differences in scores over time.ResultsWe found that over time, cortical screw fixation resulted in a mean decrease of 27 from the baseline ODI at six to eight months (p = 0.014). Additionally, six out of seven (86%) patients who had at least 12 months of radiographic follow-up showed fusion.ConclusionsCortical screw fixation showed a decrease of 27 from the baseline ODI at six to eight months, which is comparable to changes from the baseline ODI reported in three, recent, large clinical trials examining functional outcomes following traditional pedicle screw fixation. Pedicle screw fixation has been the mainstay technique for greater than 120,000 lumbar fusions performed in the United States every year [There have been numerous studies examining the biomechanical properties of the cortical bone trajectory versus the traditional pedicle screw trajectory, overall showing the equivalence or superiority of cortical screws -12. A stDespite the promising biomechanical studies, there is a dearth of literature on functional outcomes for patients that have undergone cortical screw fixation. Chen et al. recently published the first prospective cohort study on pain outcomes after cortical screws, showing that cortical screw patients had a trend towards less peak postoperative pain (p= 0.09) in the short term (one to three days post-surgery) but increased pain (p = 0.2) in the long term (six to eight months post-surgery) compared to pedicle screw patients . In addiPatient selectionThis study is a retrospective review of prospectively collected data of patients who underwent cortical bone trajectory screw placement by the senior author at a large county hospital. Cortical bone trajectory pedicle screw placement is the standard of care for all patients at our institution operated on by the senior author with a lumbar degenerative disease requiring instrumented fusion of one to three levels. Patients with a pedicle diameter lower than seven millimeters on computed tomography (CT)/magnetic resonance imaging (MRI) receive instrumented fusion using traditional trajectory pedicle screw placement. Indications for fusion include unstable spondylolisthesis (instability on flexion-extension) and spondylolisthesis over grade two. An interbody graft is placed if there is a collapse of the disc space with resulting neuroforaminal stenosis.A total of 10 patients were included in this study and underwent cortical trajectory screw placement. Informed consent was obtained from all patients prior to their procedure, which included consent for sharing intraoperative images and videos for teaching/publication purposes. All patients undergoing spinal surgery at Santa Clara Valley Medical Center (SCVMC) are encouraged to fill out functional outcome questionnaires before and after surgery in the clinic as the standard of care. The data is collected prospectively in real time in the patients’ electronic medical record. Institutional review board permission was obtained through SCVMC (#17-027) prior to analyzing any patient data, all of which was appropriately de-identified to comply with Health Insurance Portability and Accountability Act (HIPAA) protocols.Surgical techniqueThe cortical screw technique requires significantly less muscle and lateral dissection, as well as a smaller longitudinal incision, as compared to traditional pedicle screw fixation. The starting point for cortical screws is at the junction of the superior articulating process and pars interarticularis, with a medial to lateral angulation , and 25 degrees cranially in the sagittal plane. Actual angulations vary and were delineated by intraoperative fluoroscopy. A seven-millimeter minimum pedicle diameter cut-off was used in order to safely perform cortical screw fixation without lateral vertebral body breach or pedicle fracture. Arthrodesis was performed over the facet joints and in some cases of significant disc collapse, posterior lumbar interbody fixation (PLIF) using allograft was performed to restore disc height and decompress the neuroforamina.Statistical methodsWe examined functional outcomes in our cohort of patients at six to 12 weeks and six to eight months after cortical screw placement. Functional outcomes were measured by the Oswestry Disability Index (ODI) and Roland Morris (RM) disability questionnaire. The Kruskal-Wallis test and Dunn’s multiple comparison were used to analyze changes in disability measurements over time and at fixed intervals, respectively. A p-value of less than 0.05 was considered statistically significant. GraphPad Prism v 6.0  was used to conduct all statistical analyses. Fusion was independently assessed by a neuroradiologist on anterior-posterior (AP) and lateral X-rays as well as flexion-extension films of the spine. Fusion was assessed by the presence of bridging bone between the intended levels of fusion, as well as stability on flexion-extension X-rays.A total of 10 patients were included in the study and underwent cortical screw fixation. The mean age was 56 years, 40% were women, 50% smoked earlier, and the mean preoperative ODI was 70 while the mean preoperative RM was 15.3  patients who had at least 12 months of radiographic follow-up showed fusion. Ultimately, seven out of 10 (70%) had documented radiographic fusion over a mean follow-up time of 14.7 months .Cortical screws are a minimally invasive alternative to pedicle screw fixation Figures -4. SeverWe found that cortical screw fixation results in a statistically significant functional improvement for patients with a lumbar degenerative disease and spinal instability as measured by ODI. Specifically, we found that, on average patients who underwent cortical screw fixation experienced a decrease of 27 from the baseline ODI at six to eight months follow-up. The majority of the functional improvement was seen by the six to 12 weeks follow-up, as patients reported a change in the baseline ODI of -24.25 by that mark. This early improvement shows that approach-related discomfort from this less invasive technique resolves early and that the rigid spinal fixation accorded by cortical trajectory screws is very effective at immobilizing the spine and reducing the pain stemming from spinal instability.Although our present study reported progressive decreases in RM scores with cortical screw fixation, the average decrease was not found to be statistically significant. In general, while RM and ODI scores are the two predominant scales used to assess functional disability from back pain, it has been noted by Roland et al. that ODI scores are better for assessing functional outcomes in patient populations with a chronic severe disability like ours . OverallFrom our present study, it can be concluded that cortical bone trajectory screw fixation results in improved functional outcomes for patients. However, the question remains as to how these functional outcomes following cortical screw fixation compare to those following traditional pedicle screw fixation. Several, recent, large-scale trials examining functional outcomes following traditional pedicle screw fixation provide a source of comparison for our data. Specifically, Ghogawala et al. found that traditional pedicle screw fixation results in a decrease of 12.4 from the baseline ODI at six weeks and of 25.9 at six months . Forsth Traditional pedicle screw fusion rates have been cited as high as 96.3% by Sakura et al. and were found to be 89.5% with PLIF by Lee et al. Our fusion rates were 86% (six out of seven) in patients who had at least one year of radiographic follow-up. Our overall fusion rate was 70% (seven out of 10) with a mean follow-up of 14.7 months. Despite their lower fusion rate, our patients had excellent functional outcomes at six to eight months after surgery. This suggests that even in the absence of radiographic fusion, cortical screws are more than adequately immobilizing a joint, resulting in less pain and thus better outcomes. Further support for this notion comes from the fact that even in the case of our three patients that did not show radiographic fusion , none showed signs of instability on imaging as defined by movement on flexion-extension, haloing around screws, and screw pullout or fracture.There are some limitations to our study, including the lack of randomization and the small sample size. This is also a single-institution study, with all surgeries performed by a single surgeon only. Future randomized studies with a greater number of patients and longer follow-up will be needed to firmly establish cortical trajectory pedicle fixation as a first-line option for lumbar spinal fixation in degenerative spine disease.This is the first study to show a significant functional improvement in degenerative joint disease patients with spinal instability following cortical screw fixation, with or without an accompanying PLIF. The functional improvement seen was equivalent to the functional improvement seen in patients with traditional lumbar pedicle fixation in recently published large series. Future randomized studies with a greater number of patients and longer follow-up will be needed to firmly establish a cortical trajectory pedicle fixation as a first-line option for lumbar spinal fixation in degenerative spine disease and spinal instability.


Here, we provide a formal verification of that forecast. The observed rise of 3.4 ppm relative to 2015 was within the forecast range of 3.15 ± 0.53 ppm, so the prediction was successful. A global terrestrial biosphere model supports the expectation that the El Niño weakened the tropical land carbon sink. We estimate that the El Niño contributed approximately 25% to the record rise in CO2, with 75% due to anthropogenic emissions. The 2015/2016 CO2 rise was greater than that following the previous large El Niño in 1997/1998, because anthropogenic emissions had increased. We had also correctly predicted that 2016 would be the first year with monthly mean CO2 above 400 ppm all year round. We now estimate that atmospheric CO2 at Mauna Loa would have remained above 400 ppm all year round in 2016 even if the El Niño had not occurred, contrary to our previous expectations based on a simple extrapolation of previous trends.In early 2016, we predicted that the annual rise in carbon dioxide concentration at Mauna Loa would be the largest on record. Our forecast used a statistical relationship between observed and forecast sea surface temperatures in the Niño 3.4 region and the annual COThis article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’. Therefore, Keeling informally predicted that October 2015 would be the last time that monthly concentrations below 400 ppm would be seen in the Mauna Loa record.By September 2015, indices of the El Niño Southern Oscillation (ENSO) were showing strong El Niño conditions [ntration , except ntration . Anotheret al. [2 concentration between 2015 and 2016, using observed and forecast sea surface temperatures (SSTs) in the equatorial east Pacific Ocean and a statistical relationship between SSTs and the annual CO2 increment. Our published forecast was for the annual mean CO2 concentration for 2016 measured at Mauna Loa to be 3.15 ± 0.53 ppm higher than that for 2015  against annual anthropogenic emissions (ɛ) and the annual mean anomaly in sea surface temperatures in the region of the equatorial Pacific Ocean characterizing ENSO activity (N):2 rise [2 forecast, the regression was recalculated using SSTs averaged over the Niño 3.4 region  because the El Niño conditions were focused more in the eastern Pacific rather than the central Pacific as in 1997–1998. Previous work [2 increments between successive years i − 1 and i, the strongest correlation with observations was seen when N was the annual mean from 1st April in year i − 1 to 31st March in year i, so this period was used here. Annual mean April–March SSTs were taken from the HadSST3.1.1.0 dataset [i − 1, expressed in GtC. CO2 concentrations were taken from the Mauna Loa dataset maintained by the Scripps Institution of Oceanography [2 concentrations. The Mauna Loa measurements were chosen as the focus of the forecast as they provide a very specific, precisely measured quantity—in contrast, the global mean concentration relies on estimates and assumptions, which introduce additional uncertainties. Although CO2 is measured at other sites, Mauna Loa is the original measurement site and provides the longest record as well as being of historical interest.The COCO2 rise , using Sous work  had show dataset ,15 and a dataset —emissionα1 = −0.132 ppm yr−1 ; α2 = 0.415 ppm yr−1 °C−1 ; α3 = 0.237 ppm GtC−1.Using the above datasets to calculate the multiple linear regression over the period 1959–2014, using the data available in October 2015, resulted in the following values of the regression coefficients: 2 increment between 2015 and 2016 was calculated at the end of 2015 using equation  showed a very good agreement with the range based on observations for the whole year (which were not available at the time of the forecast). The mean of realizations for the 12-month period was 1.85 ± 0.19°C, slightly less than the predicted value used in making the forecast (2.02 ± 0.23°C). This was not a significant difference considering the strong ensemble overlap and the year-to-year differences in annual mean Niño 3.4, which ranged from approximately −1.5 to +2.0°C . In any year, the probability that the observed value will fall outside the forecast range is around 4%. Assuming that forecast errors are independent and normally distributed then over 5 years, the probability that at least 1 year will fall outside the range is about 21%. Over 10 years, the probability rises to 37%. For 15 years, the probability is about 50 : 50. In the long term, a good forecast would yield a predictable rate of ‘failures’.Care should be taken in the interpretation of probabilistic forecasts and their verification. The forecast of the CO4.The success of a forecast relies on two main factors: the methodology and the input data. The following discussion reflects on these.(a)2 increment). Does an examination of the carbon cycle processes support the expectations from the statistical relationship?Our successful forecast used a method that was partly process-based (the SST forecast) and partly statistical  global NBP in El Niño years . To simue change ,22.To assess the impact of the 2015/2016 El Niño, we first calculate NBP for the period 1 June 2015 to 31 May 2016—this is the 12-month period centred around the peak of the SST anomaly in December. We then calculate the NBP for the same period starting in each of the previous 10 years and find the mean of this as a comparison with 2015–2016.2 fertilization, with some contribution of climate change, particularly warmer regional climates at higher latitudes. Other terrestrial biosphere models produce similar results [2 fertilization and climate effects. Negative NBP in some regions may also be due to regional climate changes causing conditions to be less favourable for vegetation growth or enhancing soil respiration.On average over 2005–2014, JULES simulates most of the terrestrial biosphere to be a net sink of carbon in the annual mean a. In JUL results ,24. Some−1.The land–atmosphere carbon fluxes vary across the year. JULES simulates a global peak uptake in June coinciding with the boreal summer and a net carbon loss during the boreal winter a. The seDuring the 2015/2016 El Niño, the temperate and boreal regions are simulated to have become weaker sinks of carbon, and much of the tropics became a net source b. Substa2 in the atmosphere than would have been the case if 2015/2016 had been the same as the previous decade, equivalent to 1.86 ppm.This weakening of the global land carbon sink is simulated throughout the 12-month period b. In JunThe regional climate anomalies associated with the 2015/2016 El Niño therefore reduced simulated terrestrial carbon uptake in JULES. Overall, JULES simulated the tropical land areas to have switched from a sink of 1.07 GtC to a source of 2.63 GtC.2 rise [2) of Brazilian Amazonia affected by at least one active fire detection, experiencing significant positive (p < 0.1) active fire anomalies [p < 0.05–628 901 km2) was approximately twice as large as anomalies observed during the 2005 and 2010 droughts . It was estimated that gross committed CO2 emissions from Amazonia for 2015 reached a total 0.52 Pg CO2 [2 as measured at Mauna Loa. Peak fire activity in South America occurs in August and September, so the El Niño impacts on fire emissions from Amazonia are likely to have affected the CO2 rise in 2015 rather than 2016.The JULES simulations do not explicitly represent wildfire, which can also play a role in carbon emissions from ecosystems during El Niño events. In the 1997/1998 El Niño, extremely high fire emissions from Indonesian forests contributed to the faster CO2 rise , but Ind2 rise . In Amaz2 rise . The 201nomalies . In this2 Pg CO2 . However2 concentration rising faster than usual. This suggests that the statistical relationship between Niño 3.4 SSTs and CO2 annual increment is supported by understanding of the Earth system processes and appropriate for use in forecasting the CO2 rise.These model results support previous expectations that the 2015/2016 El Niño caused a weakening of the terrestrial carbon sink, which resulted in the atmospheric CO(b)The shape of the seasonal cycle is assumed to be stationary in our method. This implicitly assumes no change in the growth rate across the year, which is contradicted by of the observations of varying in-year growth rates. Nevertheless, it appears that the assumption of stationarity may be valid for predicting the annual maximum and minimum monthly values, as there is little long-term trend in the amplitude of the seasonal cycle .Regarding the in-year growth rates, 2015 had a large growth rate because the concentrations at the end of the year were anomalously high. Nevertheless, the in-year growth rate was still large across 2016 despite concentrations already being anomalously high at the start of the year. The JULES simulations suggest that the land–atmosphere carbon fluxes were impacted by El Niño until at least June 2016 , so it s2 concentrations for October–December, which were combined with observed monthly concentrations to give an estimate of the mean CO2 concentration for 2017 in time for publication before the end of the year. That combined observed/forecast estimate verified better than the forecast issued at the start of the year [2 concentrations but cannot currently be forecast with skill more than a few months in advance. However, the annual GCB calculations are routinely made in or around August, which is when signals of ENSO start to emerge. Therefore, it may be possible to develop a method for forecasting the monthly CO2 concentrations for the final few months of the year at this time, for inclusion in annual GCB calculations.These issues are important in the context of the annual Global Carbon Budget (GCB) calculations –13. Thatthe year  when com2 concentrations measured at a single site such as Mauna Loa may be affected by other factors in addition to those arising from the impacts of climate variability on surface–atmosphere carbon fluxes and the global mean CO2 concentration. For example, local wind directions different from the climatological average could make a difference. In such cases, the monthly anomalies would not be representative of the global anomaly—the Mauna Loa concentration is normally regarded as a proxy for the annual global mean concentration, but this may not always be the case, especially on shorter timescales. Investigation of this is outside the scope of the current paper, but could involve comparison with monthly anomalies at other CO2 measuring stations around the world. In future Mauna Loa CO2 forecasts, it may be appropriate to calculate error estimates for forecast monthly concentration that account for these additional uncertainties, rather than using the same error estimate as for the annual mean forecast.Monthly CO(c)2 forecast themselves include predictions—the SSTs for the coming months and the emissions. We can assess the importance of these by performing a hindcast, i.e. recalculating the forecast using equation . This would affect the regression of COequation  and reviequation .Table 32 increment to 3.21 ppm, further from the observed value, but with the forecast error estimate still encompassing the observed value.Using updated regression coefficients from the GCB 2017 dataset  and the The overall conclusion is that neither perfect knowledge of the SSTs and emissions nor updating the regression coefficients on the basis of more recent data would have given a more ‘accurate’ forecast in terms of agreement of the central estimate with observations. However, these updates would also have not caused the forecast to be ‘inaccurate’ in terms of the observations falling outside of the forecast error bars. The forecast using information available at time therefore appears to be robust to the uncertainties in the input information.5.(a)2 rise for the decade prior to 2015 was steady at approximately 2.1 ppm yr−1, so the rise of 3.39 ppm in 1 year was a substantial increase. Before 2015, the growth rate did not rise despite an increase in anthropogenic emissions, and this has previously been attributed increased net uptake of carbon by the terrestrial biosphere due to increased CO2 fertilization accompanied by a lack of increase in respiration resulting from the temporary slowdown in the rate of global warming [2 increments using equation .The contrasting definitions of year-to-year annual increment and in-year growth rate make an important difference to the year identified with a record growth rate due to the 2015/2016 El Niño. Focusing on the increment in annual mean concentrations leads to 2016 being identified as the year with the most rapid increase in CO(b)2 rise can be estimated by recalculating equation , and this arises from a spike in the land use emissions [Three caveats should be borne in mind concerning this. The first is the 10% underestimate of the observed CO997/1998 a, and thmissions  associatmissions . This te2 annual increment in 2015–2016 was larger than 1997–1998 is that anthropogenic emissions increased substantially in that period. Emissions had risen by 2.7 GtC between 1997 and 2015 (an increase of over 30%).Despite these caveats, it appears that the main reason why the CO(c)2 concentration without the influence of the El Niño can be estimated in two ways. The first method is a simple linear extrapolation of the previous trend of 2.1 ppm yr−1, as in our forecast paper [2 concentration for September 2015 was 397.50 ppm, so this would give a September mean CO2 concentration of 399.60 ppm (2 concentration for 2016 (403.31 ppm—2 could have remained above 400 ppm all year round in 2016 even without the El Niño.The monthly COst paper . The CO29.60 ppm . HoweverThe second method relies on the assumption of the stationary amplitude of the seasonality and hence assumes that the estimated contribution of El Niño to the 2015–2016 annual increment is representative of the contribution to the September 2016 concentration. A further assumption is that the annual increment is being added to a baseline that it not affected by the El Niño. With the Niño 3.4 anomaly already being strongly positive by September 2015, and the effects on land–atmosphere carbon fluxes already being evident in model simulations for that month , this as6.2 rise between 2015 and 2016 was successfully forecast in advance, using a seasonal forecast of sea surface temperatures and a statistical relationship with CO2. The successful calculation of the annual CO2 rise is robust to updates to the input data using observed SSTs and more recent data on emissions. The 2015/2016 CO2 rise was faster than the average over previous decade, due to the impact of El Niño acting mainly on tropical ecosystems. The annual CO2 rise had barely increased over the previous decade due to a prevalence of La Niña conditions, so the cessation of this influence also contributed to the large increase in CO2 rise in 2016. The 2015/2016 CO2 rise was also faster than that following the previous large El Niño in 1997/1998, due to the increase in anthropogenic emissions since then. 2016 was the first year in the Mauna Loa record when monthly CO2 concentrations remained above the symbolic threshold of 400 ppm all year, and previously, we had suggested that this would not have been the case without the influence of the El Niño. However, a revised estimate suggests that the annual minimum CO2 concentration at Mauna Loa may have remained above 400 ppm even in the absence of El Niño, due to ongoing anthropogenic emissions. The forecast of the CO2 annual increment has since become a regular product in the Met Office long-range forecast portfolio and a new component of the annual Global Carbon Budget. Further refinements to the forecast could be made, particularly concerning the shape of the seasonal cycle and the in-year CO2 growth rate.A record CO