Even though pedicle screw application is a common procedure, and in-spite of spine surgeons being proficient with the technique, mal-positioning of pedicle screws can still occur. We intend to determine by postoperative CT analysis, the incidence of pedicle screw breach in the thoracolumbar spine despite satisfactory intraoperative placement confirmed by fluoroscopy.Consecutive patients diagnosed with thoracolumbar fractures who underwent open or minimally invasive posterior stabilization under fluoroscopic guidance were retrospectively reviewed. Postoperative CT scans of patients were analysed to determine the incidence of pedicle breach despite satisfactory intraoperative placement, and also to determine the factors that can predict a breach during intraoperative assessment.A total of 61 patients with 513 thoracolumbar pedicle screws were available for analysis. Based on our postoperative CT assessment, 28 screws  had breached the pedicle. There were 14 minor (<3 mm) and 14 major (≥3 mm) breaches. The minimally invasive technique had a significantly lower breach rate compared to open surgery (1.9% vs. 7.9%). By retrospectively analysing the intra-operative fluoroscopic images, we determined certain parameters that could predict a breach during surgery.Pedicle breaches can still be present despite satisfactory placement of screws visualized intra-operatively. A medial breach is most likely when the length of the pedicle screw spans only up to 50% of the vertebral body as seen on the lateral view but the pedicle screw tip has already transgressed the midline as seen on an AP view. A lateral breach is likely when the tip of the pedicle screw is overlapped by the screw head or is only minimally visualized on an AP view. Posterior stabilization using pedicle screws and rods is a long-established gold standard technique of spinal fixation which plays an important role during surgery for spinal instabilities, deformity, degeneration, infection and tumours –7. AlthoWith approval from our institutional review board, electronic records of consecutive patients diagnosed with thoracolumbar fractures who underwent posterior stabilization during a particular period were retrospectively reviewed. Only those patients who had their intraoperative fluoroscopic images and postoperative CT scan images saved in our picture archiving and communication system (PACS) were included for analysis. Since we do not routinely perform a postoperative CT scan except for patients with thoracolumbar fractures, other patients with tumour, infection, degenerative conditions, and deformity, had to be excluded. All procedures were performed by the same surgical team using either the open approach or the minimally invasive approach, and the pedicle screws were placed under fluoroscopic guidance.In the open approach, a standard posterior midline incision was made, and layer wise dissection was carried out to expose the posterior elements including the facet joints and transverse process of the segments to be instrumented. The entry point for both the thoracic and lumbar pedicles were made as per described techniques based on anatomical landmarks , 16. PedThe postoperative CT scans were analysed by a clinician who was not a part of the surgical team. Pedicle breach was classified into three grades: 1) No breach, 2) Minor breach (<3 mm) and 3) Major breach (≥3 mm). This classification was based on other published clinical studies demonstrating that breach rates up to 3 mm could be associated without serious complications . We alsoAll statistical analysis was performed using Stata, version 13 , with statistical significance being defined as a p value of <0.05. The Chi-square test or Fischer's exact test was used wherever appropriate to determine significance. The study was approved by our institutional review board and was performed in accordance with the ethical standards laid down in the most recent version of the 1964 Declaration of Helsinki, or comparable ethical standards.The selected sample consisted of 61 patients  with a mean age of 40 years (Range = 19 – 77 years). All patients had sustained thoracolumbar injuries and underwent surgery in the form of posterior stabilization using pedicle screws and rods. A total of 513 pedicle screws were applied under fluoroscopic guidance. Based on our post-operative CT assessment, 28 screws (5.5%) had pedicle breaches; among which, 18 occurred in the thoracic spine, while 10 occurred in the lumbar spine . There wBy retrospectively evaluating the intra-operative radiographs of patients who were identified to have a breach, we derived some fluoroscopic parameters that would suggest the same during surgery. A medial breach is most likely when the length of the pedicle screw spans only up to 50% of the vertebral body as seen on the lateral view but the pedicle screw tip has already transgressed the midline as seen on an AP view . A laterTechnological advancements have made spine surgery safer, predictable and precise –20. HoweSome studies have shown no significant difference in breach rate between open and percutaneous approach , 27; wheFrom our study, it was also evident that breaches occurred more frequently in the thoracic pedicles than the lumbar pedicles. This could be attributed to the smaller size of the thoracic pedicles and its proximity to the midline when compared to lumbar pedicles –34. SimiA cadaveric study done by Agarwal et al found the sensitivity and specificity of postoperative CT scans to pick up pedicle screw breach was 91.52% and 95.02% respectively . HoweverWith the advent of neuromonitoring, intra-operative assessment of potential pedicle breaches that can compromise neurological integrity has improved , 40, 41.Among a total of 513 pedicle screws, 28 screws (5.5%) were found to have breached the pedicle; of which, there were 14 minor (<3 mm) and 14 major (≥3 mm) breaches. The minimally invasive technique had a significantly lower breach rate compared to open surgery (1.9% vs. 7.9%). Breaches occurred more frequently in the thoracic pedicles than the lumbar pedicles. We identified certain parameters on intra-operative fluoroscopic imaging to predict a possible pedicle breach: 1) When the length of the pedicle screw spans only up to 50% of the vertebral body but the pedicle screw tip has already transgressed the midline as seen on an AP view, then there is most likely a medial pedicle breach and 2) When the tip of the pedicle screw is overlapped by the screw head or is only minimally visualized on an AP view, then there could be a lateral breach.


Whilst l-NAME led to a reduction in the number of excitatory structures, inhibitory synaptic puncta were increased at P21 in comparison to administration of the inactive stereoisomer d-NAME. Finally, l-NAME decreased levels of the phosphorylated form of myosin light chain in the nucleus, which is known to regulate the actomyosin contraction apparatus. These outcomes indicate that physiologically synthesized NO modulates excitatory/inhibitory balance during early postnatal development by acting as an anti-synaptotrophic and/or synaptotoxic factor for inhibitory synapses, and as a synaptotrophin for excitatory ones. The mechanism of action could rely on the modulation of the actomyosin contraction apparatus.Synaptic remodeling during early postnatal development lies behind neuronal networks refinement and nervous system maturation. In particular, the respiratory system is immature at birth and is subjected to significant postnatal development. In this context, the excitatory/inhibitory balance dramatically changes in the respiratory-related hypoglossal nucleus (HN) during the 3 perinatal weeks. Since, development abnormalities of hypoglossal motor neurons (HMNs) are associated with sudden infant death syndrome and obstructive sleep apnea, deciphering molecular partners behind synaptic remodeling in the HN is of basic and clinical relevance. Interestingly, a transient expression of the neuronal isoform of nitric oxide (NO) synthase (NOS) occurs in HMNs at neonatal stage that disappears before postnatal day 21 (P21). NO, in turn, is a determining factor for synaptic refinement in several physiopathological conditions. Here, intracerebroventricular chronic administration (P7–P21) of the broad spectrum NOS inhibitor  Synaptic remodeling during neonatal development lies behind neuronal networks refinement and nervous system maturation. The adjustment and/or removal of existing synapses and the generation of new synapses are the substratum for synaptic reorganization occurring in learning, memory formation, and refinement of sensorimotor functions , which is synthesized by NO synthase (NOS). NO is a three-dimensional-acting diffusible factor “necessary” and “sufficient” for synaptic stripping of adult HMNs in pathological conditions -nitro-l-arginine methyl ester, l-NAME) differentially affected excitatory and inhibitory inputs, then, altering excitatory/inhibitory ratio in the HN. Furthermore, l-NAME induced a reduction in the levels of pMLC in the nucleus, suggesting that mechanism by which endogenous NO regulates synaptic refinement could involve the actomyosin contraction apparatus.Here, we hypothesize that endogenous NO determines excitatory/inhibitory balance in the HN during early postnatal maturation. Thus, chronic administration of a NOS inhibitor  Wistar rats of either sex were obtained from an authorized supplier . Animal care and handling followed the guidelines of the European Union Council  on the use of laboratory animals. Experimental procedures were approved by the local Animal Care and Ethics Committee  and the Ministry of Agriculture, Fisheries and Rural Development . Experimental animals were individually housed with their mother in cages with water and food pellets available ad libitum, at 21 ± 1 °C, with a 12-h light/dark cycle. Efforts were made to minimize the number of animals used and their suffering. All surgical processes were carried out under aseptic conditions. At least three animals per experimental condition were used. Data obtained from 27 pups were used for this study.2) animals received intramuscularly atropine (0.2 mg/kg) and dexamethasone sodium phosphate (0.8 mg/kg). The absence of withdrawal reflexes was considered a signal of sufficient deep anesthesia. Subsequently, pups were fixed with appropriated adaptors in a stereotaxic frame and the skin was incised longitudinally after disinfecting. The infusion cannula was carefully advanced throughout a drilled round window (0.5 mm in diameter) in the midline of the interparietal–occipital bones junction. Cannula was placed in parallel and close to the inner portion of the occipital bone . All animals received one post-operative injection of penicillin  to prevent infection. Pyrazolone  was given on awakening for post-operative analgesia. Drugs (l-/d-NAME) were dissolved in sterile saline and their concentration were adjusted to assure a chronic delivery of 180 mg/kg/day for 2 weeks.After habituation for 48 h, the infusion system was implanted at P7 and, subsequently, pups were housed with their respective mother. Only animals which appropriately recovered after surgery were included in the study . For drug delivery into the fourth ventricle a stainless steel brain infusion cannula (30 gauge) was chronically implanted and connected by a Vinyl catheter (Alzet Brain infusion kit 3) to a osmotic minipump . Anesthetized , the vesicular GABA/glycine transporter (VGAT), to identified excitatory and inhibitory structures, respectively, and the non-phosphorylated form of neurofilament H (SMI32) as a motor neuron marker. Sections were rinsed in PBS and immersed in 2.5% (w/v) bovine serum albumin, 0.25% (w/v) sodium azide, and 0.1% (v/v) Triton X-100 in PBS for 30 min, followed by overnight incubation at 4 °C with the combination of VGLUT2/SMI32 or VGAT/SMI32 antisera. Polyclonal primary antibodies anti-VGAT , developed in rabbit; anti-VGLUT2  developed in guinea pig; and monoclonal primary antibody anti-SMI32  developed in mouse were used in this study. Subsequently, the tissue was rinsed 3 times with PBS for 5 min each and incubated for 2 h at room temperature with the secondary antibodies, developed in donkey: anti-rabbit, anti-guinea pig, and anti-mouse IgGs labeled with the cyanine 2, 3, or 5  . Finally, sections were washed with PBS and mounted on slides with a solution containing propyl gallate . Animals and tissue were processed in parallel.z-plane in which maximum antibody penetration was evidenced. For multichannel image acquisition, fluorophores were excited alternately. Pinholes were set to the same airy unit for each laser to obtain identical optical section thickness. For comparison between different experimental conditions, images were acquired using the same settings. The perimeter, density, fluorescent intensity, and dimensions of immunolabeled structures were assessed with ImageJ 1.48 v (NIH). Only HMN somata at the level of the nucleus were included in the study. Images for quantification were flattened and background-filtered to enhance cluster outlines and an user-defined intensity threshold was applied to select puncta as previously described . On the other hand, a grid composed by 16 squares (10 μm × 10 μm) was randomly distributed along the HN in each section to characterize puncta in the neuropil. Only those synaptic structures included in squares that did not contain somata were analyzed  in neuropil was compared between treatments. Treatments were blinded for researcher who performed measures.Sections were analyzed using an Olympus FV1000-MPE confocal microscope . Omission of the primary antibodies resulted in no detectable staining. Images for quantification were acquired under a 40 × oil-immersion objective through a d-LAME or l-NAME : 26 NaHCO3, 10 glucose, 3 KCl, 1.25 NaH2PO4, 2 MgCl2, and 218 sucrose. Slicing and microdissection of HNs were both performed in ice-cold (< 4 °C) S-aCSF supplemented with protease  and phosphatase inhibitors. Transverse slices (300–400-μm thick) were obtained using a vibroslicer . Microdissected HNs were homogenized in lysis buffer  supplemented with protease and phosphatase inhibitors using a 1-ml syringe. Equal amounts of protein were processed for SDS-PAGE and immunoblotting, using a specific antibody against pMLC  and MLC  developed in goat and rabbit, respectively. Membranes were also probed with anti-α1-tubulin antibody  developed in mouse, as a control for the total amount of protein contained in each well.Tissue extraction and western blotting have been performed as previously described  was chronically infused in the fourth ventricle from P7 to P21 by means of an osmotic minipump  and linear density (+ 9.2 ± 2.9%) of inhibitory puncta (VGAT-ir) apposed to HMNs somata, in comparison with animals which received the inactive stereoisomer d-NAME  than after d-NAME-treatment  and linear density (− 19.6 ± 1.7%) of VGLUT2-ir puncta apposed to HMN somata, in comparison with animals which received the inactive stereoisomer d-NAME , but not size, of VGLUT2-ir structures  was performed to label a subtype of excitatory synaptic inputs. In contrast to what happened with inhibitory puncta, l-NAME, the excitatory/inhibitory balance was strongly altered in comparison with ratio observed in d-NAME-treated animals  under l-NAME-treatment  relative to d-NAME-treatment (+ 198.0 ± 0.9%) (Table l-NAME induced a decrease (~ − 45%) of the area occupied by VGLUT2-ir in relation to VGAT-ir puncta  was lower than after administration of the NOS inhibitor (94.5 ± 1.1 μm)  and MLC (− 47.2 ± 9.2%), although did not alter total amount of MLC (− 12.1 ± 10.4%) in the HN, in comparison to d-NAME-treated rats  as compared with that we obtained from untreated HMNs at P7 (6.6 ± 0.49/100 μm)  relative to that we previously reported at P7 (19.9 ± 0.8/100 μm)  up-regulates during postnatal development. Interestingly, NO increases HMNs excitability by facilitating Ih current, and enhances input resistance and reduces rheobase (González-Forero et al. Dysregulation of NO synthesis and/or NOS expression has been suggested to lie behind synaptic dysfunction associated with cognitive decline in many neurological conditions (Moreno-López et al.


The biomechanics of C1 posterior arch screw and C2 vertebral lamina screw techniques has not been well studied, and the biomechanical performance of the constructs cannot be explained only by cadaver testing.From computed tomography images, a nonlinear intact three-dimensional C1-2 finite element model was developed and validated. And on this basis, models for the odontoid fractures and the three posterior internal fixation techniques were developed. The range of motion (ROM) and stress distribution of the implants were analyzed and compared under flexion, extension, lateral bending, and axial rotation.All three kinds of fixation techniques completely restricted the range of motion (ROM) at the C1-2 operative level. The C1-2 pedicle screw fixation technique showed lower and stable stress peak on implants. The C1 posterior arch screw + C2 pedicle screw and C1 pedicle screw + C2 lamina screw fixation techniques showed higher stress peaks on implants in extension, lateral bending, and axial rotation.As asymmetrical fixations, C1 posterior arch screw + C2 pedicle screw and C1 pedicle screw + C2 lamina screw fixations may offer better stability in lateral bending and axial rotation, but symmetrical fixation C1-2 pedicle screw can put the implants in a position of mechanical advantage. Odontoid fracture with atlantoaxial dislocation is a serious injury impacting on the stability of the atlantoaxial joint. Atlantoaxial instability may result in disabling pain, cranial nerve dysfunction, paresis, and even sudden death . Most ofTo address these concerns, C1 posterior arch screw (C1PAS) fixation and C2 lamina screw (C2LS) fixation have been emerging as a useful stabilization technique in recent years. In 2000, Floyd and Grob  first usTo date, cadaveric biomechanical studies of C1 posterior arch screw and C2 vertebral lamina screw fixations have been performed, but the biomechanical performance of the constructs cannot be well studied only by the cadaver testing. The clinical application of both techniques was hindered all along due to a lack of precise theoretical analysis. The purpose of this study was to investigate the biomechanical properties of C1 posterior arch screw and C2 vertebral lamina screw fixations for the atlantoaxial instability to compare their stability and stress distribution of the implants against that of pedicle screw fixation.This study was supported by Sheng Jing Hospital affiliated to China Medical University. A detailed, anatomically accurate three-dimensional finite element model (FEM) of the atlantoaxial vertebra was developed based on CT images of a healthy 25-year-old male volunteer  by simpleware 6.0. The vertebral geometry data for the atlantoaxial vertebrae were obtained from the 0.5-mm-thickness CT scans (transverse slices). In brief, the established occipital-atlanto-axial complex shown in Fig. To validate our model, we compared the range of motion (ROM) of the C0-1 and C1-2 segments of the intact FEM with the results of the cadaveric experiment by Panjabi et al.  and the The FEM of intact atlantoaxial vertebrae was employed to develop the model of odontoid fracture. Screw-rod fixator models were created based on the universal cervical polyaxial screw  manufactured by Shandong Weigao Orthopedic Materials Co. Ltd. The internal fixators were implanted into the odontoid fracture model with the conventional surgical approach using the three techniques: C1-2 pedicle screws (C1PS + C2PS), C1 posterior arch screw + C2 pedicle screw (ClPAS + C2PS), and C1 pedicle screw + C2 lamina screw (C1PS + C2LS), as shown in Fig. X, −X, Y, and Z axes, respectively, to simulate flexion, extension, lateral bending, and axial rotation of the atlantoaxial joint, as shown in Fig. As the stiffness of implant is much larger than the human bone tissue, embedding constraints were used between the inserted part of the screw and the surrounding bone. The interactions among the vertebral body, cartilage, screw, and rod were defined as binding constraints. The lower surface of the axis was completely restrained; a control point was created on the upper surface of the occipital bone and coupled with all the nodes on the top of the occipital bone. A 40-N vertical downward force and a 1.5-N m moment  were appAll constructs significantly reduced ROM at operative levels compared with the intact model. In comparison with the C1PS + C2PS model, the C1PAS + C2PS model increased the ROM by 4.7% and 23.1% in flexion and extension, respectively, and reduced the ROM by 29.9% and 15.8% in lateral bending and axial rotation, respectively; the ClPS + C2LS model reduced the ROM by 3.7%, 26.4%, and 29.6% in flexion, lateral bending, and axial rotation, respectively, and increased the ROM by 28.6% in extension. Segmental ROMs of each model are summarized in Table The von Mises stress contour plot Fig.  showed tThe maximum stresses of vertebral bodies mainly occurred at the interaction between the screw and the bone. Figure For many years, clinical and experimental studies have indicated that pedicle screw fixation performs well in biomechanical stability. However, the variations of the atlas or axis always result in difficulty in implanting pedicle screws. Fixation techniques of atlas posterior arch screw and axis laminar screw are gradually becoming important supplement methods. Some literature reported that these two fixation techniques can provide comparable stability compared with pedicle screws for the unstable atlantoaxial vertebrae , 13. FewGuo-Xin et al.  studied Stress distribution on the implants is closely related to the long-term stability of fixation techniques. But much work has not been focused on investigating it. Middle and posterior portions of the screws were stress-concentrated areas. This was because the screws required to transmit the mechanical load to the rear rods. When compared with the C1PS + C2PS fixation, the ClPAS + C2PS and ClPS + C2LS showed high stress peaks on implants in extension, lateral bending, and axial rotation consistently, which indicated asymmetric fixations may result in high stress on the implants. And it demonstrates that symmetrical internal fixation can effectively improve the stress distribution of implanted segments under normal physiological loads and provide a stable force environment for the implants. Compared with ClPAS + C2PS, C1PS + C2LS showed lower stress peak in flexion, extension, and lateral bending, with similar value in axial rotation. Based on the classical three-column fixation theorem , the ancFrom the mechanical viewpoint, the ClPAS + C2PS and ClPS + C2LS fixations may offer higher stability to ClPS + C2PS in lateral bending and axial rotation, but the ClPS + C2PS can put the implants in a position of mechanical advantage.


The Scar/WAVE complex catalyzes the protrusion of pseudopods and lamellipods, and is therefore a principal regulator of cell migration. However, it is unclear how its activity is regulated, beyond a dependence on Rac. Phosphorylation of the proline-rich region, by kinases such as Erk2, has been suggested as an upstream activator. We have recently reported that phosphorylation is not required for complex activation. Rather, it occurs after Scar/WAVE has been activated, and acts as a modulator. Neither chemoattractant signaling nor Erk2 affects the amount of phosphorylation, though in Dictyostelium it is promoted by cell-substrate adhesion. We now report that cell-substrate adhesion also promotes Scar/WAVE2 phosphorylation in mammalian cells, suggesting that the process is evolutionarily conserved. Actin polymerization at protrusions such as pseudopods is an essential part of cell movement. They are initiated by the Scar/WAVE complex, which drives the activation of Arp2/3 complex, leading in turn to the enrichment of actin in the leading edges, lamellipodia, or pseudopodia . The conOne known regulator of Scar/WAVE is the small GTPase Rac1 . When inin vivo was tractable, so data about physiological roles of phosphorylation were lacking. Various domains of Scar/WAVE are phosphorylated at multiple positions. In the so-called “meander region”, tyrosine phosphorylation was found to control the activation of the complex [Phosphorylation of Scar/WAVE was described by several authors as a key activation mechanism; in most cases, this was before manipulation of the complex  complex . Serine  complex ,9, thoug complex ,10–12. H complex . The phoWe also found that the upstream driver of Scar/WAVE phosphorylation was not the expected one – chemoattractant signaling, perhaps acting through Erk2, whose activity is strongly induced by signaling . Instead2. All other cell lines were grown in DMEM supplemented with 10% fetal bovine serum or donor bovine serum and 1% L-glutamine in tissue culture dishes at 37°C, 5% CO2.Jurkat and JVM3 Cells were grown in RPMI-1640 supplemented with 10% fetal bovine serum and 1% L-glutamine in tissue culture flasks at 37°C, 5% COCells were washed twice with ice-cold PBS and lysed with RIPA buffer and kept on ice for 5 min. Cell debris was cleared by centrifugation at 13,000 rpm, 5 min, 4°C. Protein samples were boiled in 1X NuPAGE LDS buffer (Invitrogen) for 5 min and analyzed by western blotting. Proteins were resolved on self-made low-bis acrylamide (0.06% bis-acrylamide and 10% acrylamide) gels. Electrophoresis was performed at 150 V, 90 min. Proteins were electro-transferred onto nitrocellulose membrane using iblot (Invitrogen). Membranes were blocked in TBS+5% nonfat milk for 1 h at room temperature. Membranes were incubated overnight at 4°C with anti-WAVE2  and anti-tubulin (Sigma) at 1:1000 and 1:5000 dilution, respectively, in TBST+5% BSA. After washing with TBST three times for 5 min each, membranes were incubated with fluorescently conjugated secondary antibody  at 4°C, 1 h. Membranes were washed three times with TBST and protein bands were detected by Odyssey CLx Imaging System (LI-COR Biosciences).For phosphatase treatment, cells were lysed in TN/T buffer  and kept on ice for 5 min. Lysate was centrifuged  to remove the cell debris. To dephosphorylate the proteins, lysate was incubated at 30°C, 1 h with lambda phosphatase (NEB). Protein samples were boiled in 1X NuPAGE LDS buffer (Invitrogen) for 5 min and analyzed by western blotting.Protein band densities were calculated by ImageJ. A vertical line was drawn on the protein bands and intensity values of the top (phosphorylated) and bottom de-phosphorylated bands of WAVE2 were noted. The ratio of the top and bottom bands was used to represent the phosphorylation of WAVE 2 in the graph.In our recent paper , we founThe connection between cell-substrate adhesion is novel but not hugely surprising. Many cell types require adhesion to a substrate to form pseudopods or lamellipodia . Cell-su


Sawdust-reinforced ice-filled flax fiber-reinforced polymer (FRP) tubular (SIFFT) columns are newly proposed to be used as structural components in cold areas. A SIFFT column is composed of an external flax FRP tube filled with sawdust-reinforced ice. The compressive behavior of circular SIFFT short columns was systematically investigated. Four types of short columns with circular sections, including three plain ice specimens, three sawdust-reinforced ice specimens (a mixture of 14% sawdust and 86% ice in weight), nine plain ice-filled flax FRP tubular (PIFFT) specimens and nine SIFFT specimens, were tested to assess the concept of the innovative composite columns. The test variables were the thickness of flax FRP tubes and the type of ice cores. The test results indicated that the lateral dilation and the development of cracks of the ice cores were effectively suppressed by outer flax FRP tubes, thus causing a considerable enhancement in the compressive strength. Moreover, the compressive behavior, energy-absorption capacity, and anti-melting property of sawdust-reinforced ice cores were better than those of plain ice cores confined by flax FRP tubes with the same thicknesses. The proposed equations for estimating ultimate bearing capacities of PIFFT and SIFFT short columns were shown to provide reasonable and accurate predictions. The low temperature in cold areas tremendously limits the use of traditional building materials, especially concrete. Water freezing causes detrimental effect on hydration reaction of the cement, resulting in severe deterioration of mechanical properties of the resulting concrete. Furthermore, the local environment will be easily polluted due to the use of concrete in construction. Therefore, there is a particular need to find a potential construction material with cost-effective and environmentally friendly advantages to replace concrete in such areas. In fact, the local ice has served as a cleaner construction material since ancient times in cold areas, such as the igloos built up by Inuit people. In addition, the compressive properties of ice have been investigated by many researchers e.g., ,2,3,4). ,3,4. 2,3More recently, fiber-reinforced polymer (FRP) composites have been increasingly used in civil engineering because of their high strength-to-weight ratios, good design flexibility, and excellent corrosion resistance even under harsh environment ,20,21,22In consideration of environmental protection and sustainable development, natural fibers have attracted the attention of many researchers as substitutable reinforcements for traditional synthetic fibers due to their advantages such as low cost, high specific strength, environmental friendliness and bio-degradability, ease of fabrication, and good structural rigidity ,32,33. DBased on previous researches on sawdust-reinforced ice  and concExperimental studies were conducted to assess the axial compressive behavior of the newly proposed SIFFT column and to verify the possibility of this column to be used as a compression member in cold regions. Effects of the thickness of flax FRP tube and the inclusion of sawdust in ice were discussed. Equations were proposed to predict the ultimate bearing capacities of circular plain ice-filled flax FRP tubular (PIFFT) short columns and circular sawdust-reinforced ice-filled flax FRP tubular (SIFFT) short columns.3 and 86% water in weight. A total of 18 circular short composite columns, including nine plain ice-filled flax FRP tubular (PIFFT) specimens and nine sawdust-reinforced ice-filled flax FRP tubular (SIFFT) specimens, were tested subjected to axial compression. In addition, three unconfined plain ice specimens and three unconfined sawdust-reinforced ice specimens were prepared as control specimens. Each series included three nominally identical specimens. All test specimens had a height of 300 mm and a nominal diameter of 150 mm, measured at the surface of ice cores. The test variables included the number of FRP layers in flax FRP tubes and the type of ice cores. It has been well established that the compressive property of ice will be improved after the inclusion of sawdust in ice due to the fiber bridging effect. However, it does not mean that more sawdust will always contribute to better compressive property of the sawdust-reinforced ice. In fact, the workability of the water–sawdust mixture will decrease when the volume fraction of sawdust exceeds a certain level, leading to more initial defects in the prepared sawdust-reinforced ice. Therefore, a decrease in the compressive property of the sawdust-reinforced ice might occur corresponding to such a large reinforcing amount. Based on the results of trial tests on sawdust-reinforced ice specimens with different volume fractions of sawdust , the sawdust-reinforced ice with a volume fraction of 26.6% sawdust was confirmed to have the best compressive properties. Based on conversion, the optimal weight ratio of the sawdust and water was 14:86 corresponding to this volume fraction. Therefore, the sawdust-reinforced ice used in this study was a mixture of 14% pine sawdust with a dry density of 0.45 g/mmThe naming rule of test specimens was described as follows. (1) It began with PI, SI, IF, and SF to indicate different specimen series . (2) The Arabic numeral denoted the number of plies of fiber fabric in flax FRP tubes. (3) The Roman numeral was introduced to distinguish three nominally identical specimens. Taking specimen SF2-I as an example, it represented an SIFFT specimen with two FRP layers in flax FRP tube and it was the first specimen within the same series. 2 was supplied by Nanjing Hitech Composites Co., Ltd., China. The nominal thickness of the sheet was 0.135 mm. The matching epoxy resin was obtained from Shanghai Sanyou Resin Co., Ltd., China. Considering that the proposed composite column would serve in cold areas, this type of epoxy resin was selected in this study due to the fact that its mechanical properties are not sensitive to the low temperature. However, low temperature will affect the viscosity and curing properties of the selected epoxy resin. So, the flax FRP tubes used in the paper were fabricated and cured at room temperature. The epoxy L-500 AS (main agent) was assisted by the hardener L-500 BS with a mix ratio of 2:1. According to ASTM D3039/D3039M-17 [Unidirectional flax fiber sheet with a surface density of 210 g/m3039M-17 , flat colaminate , thus trIn addition, in order to evaluate the bearing contribution of outer flax FRP tubes in composite columns, two nominally identical flax FRP rings with three different thicknesses, with a height of 50 mm and an inner diameter of 150 mm, were prepared and axially loaded until failure following Chinese standard GB/T 5350-2005 . The namThe main preparation processes of plain ice and sawdust-reinforced ice specimens included the following steps: (1) A PVC tube with an inner diameter of 150 mm and a height of 300 mm was capped with a wooden plate by epoxy resin, which was used as the formwork for preparing ice specimens a. (2) FoThe preparation of PIFFT and SIFFT specimens was similar to that of aforementioned unconfined ice specimens. Firstly, the flax FRP tube was prepared via wet layup process by wrapping resin-impregnated flax fiber fabric around a cylindrical steel mold with fibers oriented in the hoop direction, with an overlapping length of 150 mm. Each end of flax FRP tube was strengthened by a 45-mm-wide carbon FRP strip to avoid any premature failure at the ends. In order to constitute a formwork, one end of the prepared flax FRP tube was capped with a circular wooden plate a. The foAll axial compression tests were conducted in winter. Prior to the compression test, the temperature of all specimens should be stabilized at −3 °C, which is equal to the temperature inside the laboratory, to avoid the heat exchange between the specimens and surrounding environment during the axial compression loading. It should be admitted that the difference between the specimen preparation temperature  and specimen compression temperature  might cause some internal damage of the ice, which was ignored in this study. A more accurate experimental program remained to be conducted in the authors’ future study to take this influence into consideration. All specimens were axially loaded under displacement control at a loading rate of 1.5 mm/min. As shown in In addition to axial compression tests, melting tests were also designed in this study to evaluate the melting rate of different types of specimens. As shown in Many longitudinal cracks were developed through the whole height of the plain ice specimen during compression, which was followed by significant dilation near the mid-height region at failure a. By conThe typical failure modes of PIFFT and SIFFT specimens after the compression tests are shown in In a concrete-filled FRP tubular (CFFT) column, the axial bearing contribution of the outer FRP tube to the total load carried by the composite column would be very limited if the fibers are mainly oriented in the hoop direction. In fact, the compressive strength of an FRP tube in the orthogonal direction to the reinforcing fibers is mainly dependent on its resin matrix . TherefoIt was observed that the local buckling of the outer flax FRP tube in PIFFT and SIFFT specimens was effectively suppressed by the corresponding plain ice and sawdust-reinforced ice cores before rupture. Similarly, the local buckling of the axially loaded flax FRP rings was also not observed before reaching their peak loads. In the present study, it was assumed that the compressive behavior of the outer flax FRP tube in PIFFT and SIFFT columns can be reflected by the axial load vs. axial strain curves of the flax FRP ring specimens . As showThe axial load was simultaneously shared by the outer flax FRP tube and the plain or sawdust-reinforced ice core when a PIFFT or SIFFT column was tested under axial compression. Based on the static equilibrium as well as the axial deformation compatibility between outer tube and inner ice, the load carried by the ice core was believed to be equal to the difference between the load resisted by the composite column and the load carried by the flax FRP tube at the same axial strain, and the latter was obtained through the compression tests on flax FRP rings . It is wIn terms of hoop strain, in an FRP-confined concrete column, the FRP jacket and inner concrete were believed to have compatible deformation in the circumferential direction. In this study, the hoop strain of the flax FRP tube in PIFFT and SIFFT columns was also employed to assess the lateral strain of the confined plain ice and sawdust-reinforced ice due to the fact that the inner ice was well confined by the outer flax FRP tube until rupture. The axial stress vs. lateral strain responses of the plain ice cores and sawdust-reinforced ice cores are also exhibited in The main test results of the plain ice cores and sawdust-reinforced ice cores in PIFFT and SIFFT specimens are summarized in As shown in It is generally accepted that the lateral dilation (hoop strain) of confined concrete is a function of the axial strain. Meanwhile, the dilation of the concrete core is restricted by the confining pressure provided by steel stirrups and/or FRP jackets. Therefore, the confining pressure is dependent on the axial strain and some analytical models have been established based on this understanding ,47,48. SThe uniformity of the lateral dilation of flax FRP-confined might be reflected by the hoop strain distribution of outer flax FRP tube around the circumference. It was also of great significance to investigate the hoop strain distribution of outer flax FRP tubes in the composite columns at different loading period. In this study, specimens IF2-II and SF4-II were selected as representatives to evaluate the distribution of the hoop strains of the flax FRP tubes in PIFFT and SIFFT specimens at different loading level, respectively. In order to clearly present the variation of hoop strains obtained even at the smallest axial load, all hoop strains were normalized by the readings of SG1 at each level of loading. As shown in As we all know, a good structural member is required to have high bearing capacity, good deformability, and large energy-absorption capacity. In this study, the flax FRP composites were almost elastic until failure without yielding characteristic and the axial load vs. strain responses of PIFFT and SIFFT columns were approximately linear before reaching the ultimate state. Therefore, it was unsuitable to use peak load or ultimate axial strain alone to evaluate the energy-absorption capacity of the composite columns. In order to solve this problem, one parameter termed energy index was initially proposed by Yan and Chouw  for flaxThe average energy indexes of confined plain ice and sawdust-reinforced ice are shown in In addition, the melting rates of specimens SI and SF6 were close to each other, which indicated that flax FRP tube has little influence on the melting rate of sawdust-reinforced ice specimen. This phenomenon might be explained by the melting mechanism of sawdust-reinforced ice in SIFFT column, as shown in Taking the bearing contribution of outer flax FRP tubes into consideration, the ultimate bearing capacity kness ta . β is a analysis . It was i et al.  for FRP-It can be seen from (1)Both PIFFT and SIFFT specimens fail by the rupture of flax FRP tubes outside the additional confinement zone. The lateral dilation and the development of cracks of the ice cores are effectively suppressed by the outer flax FRP tubes. Overall, the PIFFT and SIFFT specimens exhibit relatively brittle behavior.(2)Different from the typically bilinear curves of FRP-confined concrete, the axial stress vs. strain curves of flax FRP-confined ice are quite linear. The compressive strength of confined plain ice and sawdust-reinforced ice is approximately linearly enhanced with the increasing number of FRP layers in flax FRP tubes. Sawdust-reinforced ice cores have greater compressive strength, ultimate axial strain, and energy-absorption capacity compared with plain ice cores confined by flax FRP tubes with the same thicknesses.(3)At a given axial strain, the lateral dilation of confined sawdust-reinforced ice is smaller than that of confined plain ice. The hoop strain distribution in SIFFT specimens is more non-uniform than that observed in PIFFT specimens.(4)The melting of plain ice specimen is effectively delayed by the inclusion of sawdust and the insulation of outer flax FRP tube, while the melting rate of unconfined sawdust-reinforced ice is close to that of confined sawdust-reinforced ice due to the insulation of a layer of dry wood fiber with a low thermal conductivity after the initial melting.(5)Equations are proposed to estimate ultimate bearing capacities of PIFFT and SIFFT short columns with circular sections. The predictions are shown to be in reasonable agreement with the test results.This paper presents an exploratory investigation on the axial compressive behavior of circular sawdust-reinforced ice-filled flax FRP tubular (SIFFT) short columns. In addition to SIFFT short columns, three types of short columns including the plain ice specimens, the sawdust-reinforced ice specimens, and the plain ice-filled flax FRP tubular (PIFFT) specimens were also tested to make comparisons between different specimen series. It confirmed that the proposed SIFFT columns hold great potential to be used as compression members in cold areas due to its good compressive behavior. Moreover, the SIFFT column is innovatively achieved by three types of recycled constituent materials , which might lead to a more sustainable and environmentally friendly solution. The results and discussions presented in this study allow the following conclusions to be drawn:


The inhibition of human angiotensin I converting enzyme (ACE) has been regarded as a promising approach for the treatment of hypertension. Despite research attempts over many years, our understanding the mechanisms of activation and inhibition of ACE is still far from complete. Here, we present results of all atom molecular dynamics simulations of ACE with and without ligands. Two types of inhibitors, competitive and mixed non-competitive, were used to model the ligand bound forms. In the absence of a ligand the simulation showed spontaneous large hinge-bending motions of multiple conversions between the closed and open states of ACE, while the ligand bound forms were stable in the closed state. Our simulation results imply that the equilibrium between pre-existing backbone conformations shifts in the presence of a ligand. The hinge-bending motion of ACE is considered as an essential to the enzyme function. A mechanistic model of activation and the inhibition may provide valuable information for novel inhibitors of ACE. Hypertension, a long-term medical condition known as high blood pressure, is a major risk factor for vision loss, stroke, heart failure and chronic kidney disease, and more than a quarter of the world’s adult population in 2000 had hypertension . TherapeCommon synthetic ACE inhibitors such as captopril, enalapril, alacepril and lisinopril have been on the market for decades . HoweverThe crystal structures of ACE have been determined with high resolution, which give us the overall insight of the structural molecular arrangement and their active sites ,20,21,223, and the cleft around the active site expands about 31 Å (PDB ID: 4APH). The cleft divides the sACE into two subdomains, and the active site is located on the both of their inner surfaces. Two subdomains of sACE were defined as subdomain I including the N-terminus and the zinc ion  and subdomain II including the C-terminus . Two kinds of inhibitors, BPPb  [Spirulina derived heptapeptide, Thr-Met-Glu-Pro-Gly-Lys-Pro) [In order to explore the ligand binding effects on the dynamics and the mechanisms of activation and inhibition, all-atom MD simulations of sACE were carried out with and without ligands. The simulations focus on the C domain in which the AngI is mainly converted . In the Pro-Pro)  and SPI Lys-Pro)  as compeLys-Pro) .A simulation of ligand-free sACE (Apo) was initiated from the coordinates after removing the bound AngII from the sACE-AngII complex (PDB ID: 4APH) . Like alIn order to analyze the mouth opening and closing motion, we defined two lips and calculated the distance between the centers of each lip Cα atoms throughout production stage of the simulations . Two lipIn order to investigate the flexibility of the enzyme, root-mean-square deviation (RMSD) of the Apo form and the AngII bound form were computed . As we eCα root-mean-square fluctuation (RMSF) of each form was calculated using the production stage of the MD simulation trajectories . The anaThere is no structural report for the open conformation of human ACE yet. The angiotensin converting enzyme-related carboxypeptidase (ACE2) is a homologue of the human sACE. ACE2 was also identified as the cellular receptor for the SARS coronavirus and novel coronavirus in 2019 (COVID-19) ,30. The We superimposed the closed and the open conformations of ACE and compared with those of ACE2, and the comparison revealed tremendous similarity between two systems . In addiBPPb is a competitive inhibitor isolated from snake venom . A crystThe BPPb bound sACE simulation showed the similar behavior with the AngII bound one . We analSpirulina was identified as a mixed non-competitive inhibitor (SPI) [In addition to competitive inhibition, non-competitive inhibition is also a common inhibition mechanism. Non-competitive inhibition includes pure and mixed noncompetitive inhibition. Surprisingly for us, mechanism of mixed type non-competitive inhibition for ACE has not been studied intensively so far. In the previous study, a heptapeptide (Thr-Met-Glu-Pro-Gly-Lys-Pro) derived from a marine microalgae or (SPI) . We inveThe simulation of SPI bound to sACE was started with the structure after the removing AngII from SPI bound to AngII-sACE complex, which is the result of the SPI docking simulation of the previous study . The anaIn the simulation of SPI bound to the AngII-sACE complex, the peptide bound in the N-terminal side of the mouth and next to the AngII . BindingDistance analysis of SPI bound sACE-AngII showed similar behavior to other ligand bound simulations b. IntereThe active sites and binding interactions have been well known for ACE with various inhibitors, while the conformational dynamics and its role in activation mechanism have not been studied intensively. Drug design might benefit from backbone conformations observed by MD simulations, which have never reached by the X-ray crystallography with ligand bound forms. Unlike the closed state, the open state of sACE has not been detected in both experiments and simulations so far. Surprisingly, over more than a decade since the first proposal , no furtIn contrast to the lock-and-key model, many proteins can take a ligand only through the conformational changes. The putative binding pathway of sACE might be too narrow to accommodate the substrate AngI in the closed state , thus thIn the ligand-free (Apo) MD simulation, we were able to observe spontaneous conformational changes between the open and closed states of sACE, implying that the open and closed backbone conformational states are already present and accessible regardless of the presence of a ligand. In addition, several times of conversions between the states for the 400-nanoseconds simulation indicate that the enzyme is very flexible and dynamic. Indeed, all available ACE structures are resolved in the closed conformation either in the presence ligands or with mutations. Introducing mutations, ligands or chimera are common methods to enhance thermal stability and to crystalize a protein. In addition, the absence of the open conformation in a ligand-free ACE imply the intrinsic flexibility of ACE. Again, only one available structure in the open conformation is resolved with ACE2 . In addiBased on the results of our MD simulations and available X-ray structures, we propose the following activation mechanism of sACE . RegardlSimilarly, we can derive a mechanism for a competitive inhibitor. Now, if the ligand is a competitive inhibitor, then the bound complex becomes stable in the closed state. Qualitatively, the equilibrium shift is the same way as the case of substrate binding. After release of the inhibitor, the equilibrium goes back to the first stage of the Apo form. Since AngII occupies the same active site, until the release of AngII sACE cannot take any substrate. This is true for the substrate too. Interestingly, SPI the mixed non-competitive inhibitor makes use of this. The interactions of SPI not only with sACE but also with AngII stabilized sACE in the closed state further, resulting in a dead-end complex by holding the product of enzyme AngII in the active site . Since SIn Apo simulation, we have removed the bound AngII from the X-ray structure of sACE-AngII complex and started the MD simulation. This removal of AngII is an additional perturbation to the sACE structure. We checked equilibration of the Apo system by monitoring the thermodynamic parameters such as energy, temperature, volume and pressure . In addiIn conclusion, using all-atom MD simulations, the conversion between open and closed states of sACE was observed in the absence of a ligand supporting that hinge-bending motion is essential in enzyme activation. The preferred states as well as the extent of flexibility were strongly dependent on the presence of a ligand. The transformation from the semi-open to the closed state in the bound forms was directly influenced by the interaction between the residues of binding sites of the substrate and the inhibitors. These interactions constrained the enzyme structure to remain in the semi-open and closed states. However, it would seem that the putative binding pathway is too narrow to accommodate the substrate and inhibitors. Therefore, the semi-open conformation might be the state where the ligands can bind. Our MD simulation results and the mechanistic model of sACE activation and inhibition portends not only drug design for hypotension treatment but also wide applications in molecular biophysics and beyond.Potential binding sites of SPI on sACE were searched by docking simulations using the FlexPepDock protocol of the Rosetta program . The cryTotal five molecular dynamics simulations were carried out: BPPb bound sACE, AngII bound sACE, Apo (ligand-free), SPI bound sACE-AngII complex, SPI bound sACE. Two crystal structures of the sACE co-crystallized with ligands in the active site were used to build the simulation systems, sACE complex with the natural inhibitory peptide BPPb (PDB ID: 4APJ) and sACE complex with AngII (PDB ID: 4APH). In order to simulate the Apo form, AngII was removed from the active site of the crystal structure (4APH). The SPI bound to the sACE-AngII complex with the lowest score from the docking simulations was chosen to run the fourth MD simulation, and the last SPI bound sACE model was generated by removing the AngII from this docking simulation result.Charmm36 force field with explicit TIP3P water molecules was used in all simulations . Crystal2. After that, the harmonic position restraints were removed, allowing all atoms in the systems to relax. All bonds involving hydrogen atoms were constrained, allowing an integration time step of 2 fs. The non-bonded interactions were smoothly truncated from 10 Å to 12 Å cutoff, and the particle-mesh Ewald method was used to treat long-range electrostatic interactions [All simulations were performed by NAMD under the periodic boundary condition . After sractions . The equractions . Formati


Additionally, nutrition policy and strategy documents for select global and country institutions (n = 12) were analysed to identify interventions and approaches for addressing different forms of undernutrition. The findings of this study suggest that at both global and country levels, development actors tend to prioritize stunting prevention, and emergency‐humanitarian actors tend to prioritize treatment of acute malnutrition. It was less common for wasting prevention to be mentioned as an explicit priority. Many interventions were perceived by respondents to influence both stunting and wasting despite limited published evidence of effectiveness on wasting for water, sanitation and hygiene, growth monitoring and promotion, breastfeeding promotion and micronutrient supplementation. To help unify the nutrition community around prevention of wasting, the discourse about priority interventions should shift from ‘stunting versus wasting’ and ‘prevention versus treatment’ to a life‐course framing around child survival, growth and development. Respondents identified a need for more programme and research funding that prioritizes both wasting and stunting as outcomes. They also suggest leveraging existing national coordination bodies that bring development and emergency‐humanitarian partners together.Despite a shared commitment to achieving global nutrition targets, development and emergency‐humanitarian actors tend to prioritize different nutrition outcomes and actions. New approaches are needed to bridge the divide between these communities and to strengthen the overall evidence base for prevention of wasting. To better understand how these different groups perceive and prioritize actions for wasting prevention, key informant interviews ( Ongoing divisions of the nutrition community between development and emergency‐humanitarian actors hinder the prioritization of wasting prevention at global and country levels.Despite limited or weak evidence for their effectiveness on wasting, many nutrition professionals believe that water, sanitation and hygiene; growth monitoring and promotion; breastfeeding promotion; and micronutrient supplementation will influence wasting.For promoting wasting prevention, a life‐course framing that emphasizes child survival, growth and development is likely more effective than an outcome‐focused framing on stunting and/or wasting.Programme implementation and research initiatives as well as their funding institutions should include targets and metrics for both wasting and stunting.1A range of interventions for the prevention and treatment of malnutrition in young children is being scaled up across countries with high burdens of undernutrition , an online stakeholder survey and an analysis of nutrition‐focused strategic documents from organizations that work in low‐ and middle‐income countries (LMICs). Table KII: In January–February 2018, KII were conducted with respondents from five focal countries  and several research and development partner institutions with significant nutrition portfolios. The KII component was informed by a previous systematic review from the study team , a professor of nutrition with expertise in maternal and child nutrition in low‐income contexts, conducted all KII via phone in English. The interviewer had a prior collaborative relationship with two of the 21 KII participants. The average interview duration was 40 min. Interview participants were sent the interview guide and details on researcher's goals for the project via email in advance of the interview. Verbal informed consent was obtained prior to starting the interview. The interviews were audio recorded and transcribed verbatim. No repeat interviews were conducted. Interview transcripts were analysed in Dedoose qualitative analysis  by four trained research assistants using thematic codes. The research team developed the codebook collaboratively to ensure consistent code definitions were understood by all coders. The first two interviews were used as a test case to ensure that an interrater reliability of at least 90% was achieved. In the rare case of a coding ambiguity, researchers consulted with the lead author (S. I.). All interviews were double coded to ensure consistency of data classification. To illustrate key themes, rich text quotes were extracted along with de‐identified participant information.A combined grounded theory and content analysis approach was used; codes were developed deductively from the interview guides and inductively from interview findings  from April to May 2018. The aim of the survey was to capture the perspective of a wider range of respondents working across LMIC. Participants were invited to complete the survey using a mass email distribution or personal email invitation from the authors. Emails were sent to the following listservs: The online survey was developed from the findings of the KII and asked specifically which nutrition interventions are implemented in the respondent's context and whether the divisions described in the report introduction were apparent in their context. In addition, using a list of 20 interventions identified through KII, respondents identified which outcomes  they believed each intervention would influence. Respondents were asked an open‐response question about meaningful ways to categorize interventions. For the question about whether stunting and wasting are addressed by the same project or organizations in their context, participants were given three response options  but could not select ‘do not agree’, which was an oversight in survey design.The survey was conducted in English. No sample size target was determined a priori, rather the researchers sought to obtain the largest sample possible within the specified time period. Participants provided written electronic consent; however, responses could not be linked to individual respondents due to lack of identifiers.2.2BoxStrategic documents from 12 institutions, including governments, UN agencies and NGOs working in child nutrition in LMIC were reviewed BoxA. At lBox ANational organizationsNational Strategic Plan of Action for Nutrition (NSPAN) ‐2019– NiNational Multi‐sectoral Nutrition Action Plan (NMNAP) ‐2021 – TNational Nutrition Strategy ‐2022 – IUnited Nations Agenda for the Reduction of Chronic Undernutrition in Mozambique ‐2019World Food Programme Nutrition Strategy ‐2020 ‐ BMulti‐national organizationsBill & Melinda Gates Foundation Nutrition Strategy Overview Catholic Relief Services Nutrition Program Description Children's Investment Fund Foundation Strategy Emergency Nutrition Network Strategy ‐2020International Rescue Committee Nutrition Program Description United States Agency for International Development (USAID) Multisectoral Nutrition Strategy ‐2025World Food Programme Strategic Plan ‐2021Using a triangulation design , followed by government  and university or research institutions . Common professional responsibilities included programme planning, daily programme management, research and programme evaluation. About two‐thirds  of online survey respondents worked in a single country, and one‐third  worked across multiple countries. The three most common regions for work were sub‐Saharan Africa , South Asia  and Latin America/Caribbean/South America .A total of 107 respondents participated in the online survey, of whom 75 completed all questions. The majority of respondents worked for NGOs . Another respondent noted: ‘[The prevention of stunting] has become a big, big objective in the world’ (Burkina Faso). Some participants noted that the lower prevalence of wasting may also reduce the incentive to address it: ‘Your reach in a wasting program is going to be a lot lower. Because not as many people are affected, it tends to be deprioritized a little bit’ ..One intervention I can think of on the health side is community case management. This kind of a preventive approach because you are trying to quickly get to a child at the community level with treatment for an illness which would then prevent the wasting that would come probably right after that incidence of illness. So, I think [wasting prevention] would be understood, but I really do not think we utilize it. And, whether it would be used outside of our community? You know there's been a lot more traction I would say in the general population around stunting and chronic malnutrition and how to prevent that but I think the wasting prevention may or may not stick with people Our findings did not indicate any notable differences in views regarding wasting and stunting by geographic region or working within a single versus multi‐country setting.While participants understood the term ‘wasting prevention’ and felt it would be understood in their contexts, they said it was not commonly used.The strategic document review highlighted differences in prioritization of approaches for wasting and stunting across government and development partner strategies. This analysis, summarized in Table 3.2n = 79), breastfeeding counselling , Infant and Young Child Feeding (IYCF) counselling in food‐secure settings , water, sanitation and hygiene (WASH) promotion and social behaviour change communication , and macronutrient supplementation in food‐insecure settings  as having impact on both wasting and stunting.Figure .We are stunting focused, but address wasting and the most common micronutrient deficiency: anaemia. When you make a very good promotion of IYCF practices, I think you have impact on stunting reduction, anaemia reduction, and also wasting reduction In Table KII also showed that stakeholders associate certain interventions like IYCF promotion with influencing multiple outcomes:For food supplementation interventions, stakeholder responses align well with evidence. However, a high proportion of respondents identified WASH, growth monitoring and promotion, breastfeeding promotion and micronutrient supplementation as suitable to affect wasting. The evidence base contradicts this, is weak, or does not show strong significant effects. It should be noted that the ENN review ENN,  did not n = 27) compared with those working in a single country (n = 48). Single‐country respondents were more likely to identify multiple micronutrient supplements (MMS) during pregnancy as having impact on both stunting and wasting . More than half of multi‐country respondents  selected ‘neither outcome’ for MMS compared with 13% of single‐country respondents (n = 6). There was a similar pattern of selecting ‘neither outcome’ for iron and folic acid supplementation during pregnancy  and for high‐dose vitamin A supplementation in children . The subgroup differences may be attributable to multi‐country stakeholders from UN agencies, donors or multinational NGOs having more access to global evidence reviews than those focused on single countries who are more likely to work for government or local NGOs.For the micronutrient interventions there were notable differences between respondents who worked across multiple countries ..There is huge resistance to [lipid‐based nutrient supplements] and [ready‐to‐use therapeutic food]. There are multiple dimensions to that resistance. I think that [national stakeholders] see it as sort of a multi‐national product‐driven approach. It can be taking time and resources away from programming that could be developed nationally and much more focused on improving quality of home‐based food and we cannot argue against that because there is a huge amount of poverty. It's not like people are not trying to do better, but that's their argument Evidence of division within the nutrition community.A KII respondent in Tanzania said the country has clear protocols for SAM but not for MAM treatment. A key informant in Bangladesh and India indicated that the incorporation of MAM treatment into routine health services was not possible due to capacity constraints and was ‘unsustainable’, especially for already overburdened local health centres and the high cost of MAM treatment. This respondent described a ‘massive gap in coverage’ for MAM treatment due the cost of a national community‐based management of acute malnutrition and a resistance to specialized products for addressing MAM:.Yes, I think [the development of camps] is not deliberate. I guess I see it just as a part of the history or particularly [community‐based management of acute malnutrition] in the humanitarian world where the rapid response programs were priority and I think that that's why it has been scaled up so quickly. But the flip side is that it's perhaps not integrated. I see lots more programs working to make that happen now, and lots more recognition that that's needed. So, the conversations are happening and lots of places are doing things to impact. I think it needs to continue. We need to keep talking and working through the details .The reason that stunting and wasting diverged as forms of malnutrition if you want to go back 50 years is because one responded to food and the other one did not. So, people took wasting out and said this is one we can do something about. Let us label this and promote programs along these lines and then stunting that does not respond to food and does not seem to respond to bed nets that reduce malaria transmission by 10‐fold, and you know very excellent dietary supplements. Even in the last year, stunting does not really respond to sanitation interventions. Well, what is stunting, it is not responsive to these particular things. The flaw in that kind of thinking is that, the challenge is that stunting is a multifaceted process and the interventions that are going to reduce it will have to be multifaceted. So, that is kind of my view of the landscape The online survey findings indicated a lack of strong agreement about whether the same projects and organizations address both stunting and wasting in stakeholder contexts. Only 35% agreed strongly with the statement that ‘the same projects address both stunting and wasting’ . Fewer  agreed strongly that ‘the same organizations are responsible for planning and implementing projects to address both wasting and stunting.’Online survey and KII respondents largely agreed that ‘stunting prevention’ and ‘wasting treatment and prevention’ involve different actors for funding and implementation. They had different explanations for why the divide occurred.3.3Stakeholders suggested different approaches for bridging the divide between development and emergency‐humanitarian groups. Those working across multiple countries advocated for greater harmonization in funding sources and reframing discourse and terminology around wasting. Respondents working in single countries emphasized improvements in national coordination.3.3.1Within the organizational strategic plans, the most common classifications used to describe intervention activities were using the life course  and ‘nutrition sensitive versus nutrition specific’ Table .n = 11, 27%), ‘prevention versus treatment’  and by the nutritional status being targeted  . Participants also suggested grouping interventions according to whether they achieve intermediate or long‐term outcomes , the delivery platform of the intervention , or more generally ‘targeting’ .Among survey participants, 41 suggested an alternative categorization to ‘stunting versus wasting focused’ in response to an open‐ended question. The most common suggestions were life course or age‐based . Moreover, stakeholders noted a recent shift in the conversation and increase in programming that is inclusive of wasting and stunting.I think we need to change how we talk about child growth. We need to stop talking about stunting versus wasting and just talk about child growth in general. So I think that is something to think about in the community because I think it might help move this discussion forward, and I think we need to have a better understanding of risks, too, because I know that a child that is SAM or MAM has a really high risk of mortality. For those that are chronically malnourished and stunted, I think we do not communicate enough about their risks. Like a child that is very, very low HAZ, they also have a high mortality risk at well, and I think it's even more than MAM kids. But, we need to remember that these kids are generally at risk here and we need to be doing something about it. So I think our language and how we talk about child growth could be one thing .We have created all these sort of artificial divisions for programmatic reasons, you know like SAM and MAM, wasting, stunting. But, they are all occurring in the same children, and the wasting‐stunting overlap is massive and you know we furthermore know that children are both wasted and stunted have the highest risk of mortality. So, there is a lot of talk recently, even kind of blurring those lines even more. In terms of special definitions that we are talking about when we talk about undernourished children also linking with traditional prevention programs like cash transfers, WASH … absolutely. At [our organization] we are working on integrating packages, every agency does Integration of services and harmonization of priority outcomes towards the common goal of a well‐nourished or healthy child was a repeated theme. Reframing the discourse was seen as a strategy to this end:3.3.2Stakeholders identified government as a key institution for coordination of different stakeholder groups. Specific examples including the Scaling Up Nutrition (SUN) movement in Tanzania were seen as helping to bring together nutrition professionals working across the emergency‐humanitarian and development spectrum. Efforts to bring together government with academic and the private sector were also noted as important..You know at the global level you have some of these clusters—the nutrition cluster, the health cluster, and things like that— where UNICEF tends to manage the nutrition cluster. But I think within countries is really where you need to start, and you need to have a sort of goal there, and you need to have a national nutrition policy that brings it all together as opposed to one that might be a little bit fracture .All these groups get together on a quarterly basis. [We need to] look at the specifics: what are they called? What they do plan? How do we move forward? … All these have been brought to them at the secretariat group within the nutrition sector. So, actually I think it's an example to … other sectors because we are well coordinated [in the nutrition sector]. We've picked the same language, we are serving the same plan, so we are following you wherever you are working in this big country. You have a road map to follow One multi‐country stakeholder identified Kenya and Ethiopia as countries where national‐level coordination is taking place and the same actors are involved in wasting and stunting activities..Kenya comes to mind … I feel like the people on the ground that are actually implementing nutrition programming are actually the same people that are scaling up their treatment for wasting in emergencies, and they are the same people that are investing in chronic malnutrition and stunting … Ethiopia would be another with the coordination mechanism. But, there is … still room for improvement on that Professional communities of practice and their associated listservs were also noted as a way to ‘break down some of the barriers and convene diverse groups beyond what was possible with physical meetings’ .KII respondents provided a number of examples of national‐level coordination strategies that can help bridge implementation divides..I think the bottom line though is funding, because it would be wonderful to work at the multi‐sectoral level, but it takes huge amounts of funding to implement those integrated packages … Donor money is not there for that Stakeholders noted that the breadth and complexity of nutrition make ‘developing one organization that understands the entire context and is able to program very well’ difficult, suggesting that organization expertise is needed alongside inter‐organizational coordination .Funding and technical expertise needed to address nutrition problems were cited as barriers to greater harmonization.4This study's findings confirm that despite a global target to reduce wasting .Table S4. Codebook for key informant interview analysisClick here for additional data file.


Response inhibition relies on both proactive and reactive mechanisms that exert a synergic control on goal-directed actions. It is typically evaluated by the go/no-go (GNG) and the stop signal task (SST) with response recording based on the key-press method. However, the analysis of discrete variables  registered by key-press could be insufficient to capture dynamic aspects of inhibitory control. Trying to overcome this limitation, in the present study we used a mouse tracking procedure to characterize movement profiles related to proactive and reactive inhibition. A total of fifty-three participants performed a cued GNG and an SST. The cued GNG mainly involves proactive control whereas the reactive component is mainly engaged in the SST. We evaluated the velocity profile from mouse trajectories both for responses obtained in the Go conditions and for inhibitory failures. Movements were classified as one-shot when no corrections were observed. Multi-peaked velocity profiles were classified as non-one-shot. A higher proportion of one-shot movements was found in the SST compared to the cued GNG when subjects failed to inhibit responses. This result suggests that proactive control may be responsible for unsmooth profiles in inhibition failures, supporting a differentiation between these tasks. Motor inhibition reflects the ability to withhold a ‘prepotent’ response tendency and suppress inappropriate actions; it represents a core aspect of cognitive control allowing a flexible and efficient regulation of goal-directed behavior in daily life . Motor iBehavioral evaluation of response inhibition is typically performed using the go/no-go (GNG) or the stop signal task (SST) experimental paradigms. Although often used interchangeably, the GNG and the SST might investigate different components of the motor inhibitory function ,6. In faBehavioral performance is typically quantified by a key-press method ,13. HoweAn experimental approach which contributed to the shedding of light on the dynamic nature of cognitive processes is based on the analysis of continuous trajectories of hand movements in behavioral tasks ,23. In tIn the current study, we used a behavioral method based on a mouse response-registration system to investigate proactive and reactive components of motor inhibition during cued GNG and SST tasks. Velocity profiles extrapolated from mouse trajectories were recorded and the proportion of motor responses without trajectory corrections  with no history of neurological and psychiatric diseases or drug abuse, normal hearing and normal or corrected-to-normal vision were included in the study. All participants, but five, were right-handed. No participant was currently or previously engaged in sport activity at a competitive level or professional gaming. Participants were mainly recruited from the Psychology students’ community of the University of Florence. All participants gave their written informed consent to the procedure and the processing of personal data. The study was performed according to the Declaration of Helsinki and was approved by the Ethical Committee of the University of Florence . Prior to the experimental session, each subject was blind to the purpose of the study, which was carefully explained after the completion of the evaluation.Each participant performed the cued GNG  and the The order in which the tasks were performed by subjects was randomized and counterbalanced across subjects. Each task was immediately preceded by a training session to familiarize subjects with experimental procedures. It consisted of five sample trials for each task.For both tasks, motor responses were collected using an optical gaming mouse-peripheral . The mouse was positioned on the center of a wooden board delimited by two 28 × 10 cm sponges A. Each sA preferential daily use of the right hand for a mouse device was reported also by the five left-handed subjects. Therefore, in both tasks all participants were instructed to respond with their right hand, regardless of their handedness.Visual stimuli consisted of arrows presented at the center of the screen  B. SubjecA descending series of five asterisks was presented at the beginning of each trial as a countdown to prepare the participant for the proper stimulus. This procedure was employed in order to heighten the proactive preparatory phase . For ‘GoIn order to evaluate the role of cueing during the preparatory phase on subsequent movement profiles, we used the cued version of the GNG task, manipulating the probability that the upcoming target required a response .The time between the end of the countdown and the appearance of the target varied randomly between 300 and 600 ms.The order of ‘Go-stimulus’, ‘No-Go-stimulus’ and relative asterisk countdown trials was randomized for each participant. The task consisted of 160 trials.See The SST paradigm included two conditions: ‘Go-trials’ and ‘Stop-trials’ B. Each tIn Stop-trials , the white arrow was followed by a blue arrow  pointed in the same direction. Subjects were instructed to refrain from responding or to suppress the on-going motor response when the stop-signal was presented. The blue arrow disappeared after 1000 ms or as soon as the subject failed to inhibit a motor response . The time between the white and the blue arrows  was adapted to the participant’s performance by a tracking procedure ,38,39,40The inter-trial interval was varied randomly between 2000 and 2200 ms. The order of the Go-trials and Stop-trials was randomized for each participant. The task consisted of a total of 160 trials divided into two blocks.See In both tasks, feedback on the response speed was given after ‘Go-conditions’ , in order to limit the slowing tendency which can be adopted by the participant as a strategy to improve accuracy ,42. NameFor each task and subject the behavioral performance was firstly quantified by the following measures: number of correct responses and reaction times (RT) in the Go conditions , number of inhibitory failures in the No-Go/Stop conditions , and the SSD (only for the SST). For the cued GNG, correct responses and inhibitory failures were calculated as total and as a function of the Go-stimulus probability (low and high probability). RTs were measured as the time between the stimulus appearance and the mouse movement onset. Movement onset was defined as the moment in which the subject exceeded a pre-determined threshold value . A mouse shift within 30 pixels was considered as device error. These values were chosen on the basis of preliminary recordings performed to calibrate the experimental apparatus. More precisely, one experimenter (V.B.) had to hold the mouse (230 Dots Per Inch —sampling rate 500 Hz) trying to stay as still as possible for 5 min. The farthest value obtained on the x-axes by the mouse was registered. After this, another session was performed. In an interval of time of 5 min the same experimenter had to keep the mouse still, alternating this condition with some random mouse movements. The maximum x values reached were measured. The maximum value measured between the two sessions was 30 pixels (3 mm) and it was chosen as the threshold to prevent ‘false positive’ movements. For both tasks, all mouse movements exceeding this threshold value of 30 pixels from the starting position were considered as inhibitory failures.t-test.To evaluate the overall behavioral performance, the percentage of correct responses in the Go conditions were entered in a repeated-measures analysis of variance (ANOVA) with TASK as a within subject factor . Moreover, errors rates (inhibitory failures) during high and low GO-stimulus probability of the cued GNG were compared by a paired sample As the main variable of interest, we evaluated the velocity profile extrapolated from the mouse trajectories both for correct responses obtained in the Go conditions and inhibitory failures of the No-Go/Stop conditions. We classified movements as one-shot or non-one-shot by visually inspecting each velocity profile. More precisely, a MATLAB code was used to automate the velocity profile computation and plotting to visually inspect the presence of trajectory corrections ,30. MoveThe proportions of one-shot movements calculated for either Go and No-Go/Stop conditions of both tasks were entered in separate repeated-measures ANOVA with TASK as a within subject factor .Moreover, RTs recorded for Go and No-Go/Stop (inhibitory failures) conditions of both tasks were separately analyzed as a dependent variable using a mixed-model ANOVA with TASK  and VELOCITY PROFILE (two levels: one-shot and non-one-shot movements) as fixed factors. In the analyses conducted on RTs, participants were treated as a random factor. A mixed-models approach was chosen for its flexibility to efficiently handle designs that are not perfectly balanced (as in this case), taking into account the intrinsic (and uncontrolled) variability among the participants ,30.Finally, to evaluate whether the variation in individual SSD in the SST could have influenced the velocity profile, we conducted correlational analyses. Namely, the relationship between individual SSD values and the proportion of one-shot movements was tested by calculating the Pearson’s correlation coefficients separately for inhibitory failures and correct responses. SSD values were evaluated as follow: mean SSD; final SSD; and the difference between initial SSD and final SSD.p < 0.05 and adjusted by Bonferroni-correction for multiple comparisons. Partial eta squared (ηp2) was calculated as effect size. In addition, a posteriori power analyses were performed using G*Power 3.1 software.All tests were two-tailed and significance was set at p = 0.695, ηp2 = 0.007). The proportion of inhibitory failures during for the ‘high GO-stimulus probability’ was significantly higher compared to the ‘low GO-stimulus probability’ condition (t(52) = 2.371, p = 0.02).Details on behavioral performance in the cued GNG and in the SST are given in The mean of one-shot movements calculated for either Go or No-Go/Stop conditions for both tasks are given in p = 0.103, η p2 = 0.043, power = 0.17).Results of the repeated measures ANOVA performed for the mean of one-shot movements during Go conditions did not show significant differences . Post-hoc comparisons (Bonferroni corrected) revealed that the mean of one-shot movements for either ‘high GO-stimulus probability’ or ‘low GO-stimulus probability’ conditions were significantly lower compared to those observed in the SST (p < 0.001) (p = 0.652).In contrast, the mean of one-shot movements evaluated during No-go/Stop conditions (inhibition failures) differed significantly among tasks  . In contRTs for one-shot and non-one-shot movements in either Go or No-go/Stop conditions (inhibition failures) are reported in p = 0.048, power = 0.99), whereas the main effect of VELOCITY PROFILE  and the interaction between these two fixed factors were not significant .For RTs recorded during Go conditions, the mixed-model ANOVA showed a significant main effect of TASK  or VELOCITY PROFILE , whereas the interaction between these two fixed factors was not significant . Overall, when subjects failed to inhibit responses (inhibitory failures), RTs recorded during non-one-shot movements were significantly slower compared to those recorded during one-shot movements (p < 0.001). Concerning No-Go/Stop conditions, post-hoc comparisons revealed that the RT measured in SST one-shot movements was significantly faster than in all the other conditions, except for the RT measured in one-shot movements of ‘high GO-stimulus probability’ . Additionally, the RT measured in non-one-shot movements was slower than in all the other conditions (p < 0.001).The mixed-model ANOVA conducted on RTs recorded during No-Go/Stop conditions (inhibitory failures) revealed a significant main effect of either TASK .With regard to the relationship between individual SSD values in the SST and the proportion of one-shot movements, none of the correlations performed resulted statistically significant for either inhibitory failures or for correct responses , trajectory corrections to the initial motor plan observed for inhibitory failures were less frequent. In contrast, the opposite trend emerged when the inhibitory demand was mainly proactive (as in the cued GNG). Moreover, the probability that the upcoming target required a response did not affect the subsequent movement profiles as no significant differences in the proportion of one-shot movements emerged between the high and low Go stimulus probability conditions of the cued GNG task, neither in the Go nor in the No-Go conditions. However, the possibility that the cued procedure employed (not using a block-wise design) may actually have reduced the error, effectively reducing the distinguishable difference between the two probability conditions, cannot be ruled out.We speculate that the higher proportion of inhibitory failures characterized by unsmooth trajectories observed in the cued GNG task may reflect the competition between conflicting motor tendencies (go vs. no-go) during movement preparation. Another possibility might be that the higher proportion of non-one-shot movements observed in GNG inhibitory failures could reflect movement correction attempts. Proactive control promotes the maintenance of task goals; this activity serves as a source of top-down control which optimizes bias attention, perception and action systems in a goal-driven manner . On thisAlthough previous studies ,9,10,11 Furthermore, RT analysis revealed that non-one-shot movements were always slower than one-shot movements, independent of the task. This finding may be interpreted as a consequence of proactivity. Indeed, a cost in terms of RT has been defined as a characteristic feature of proactive action; it reflects the time required to release proactive inhibitory control of responses .Admittedly, unsmooth trajectories and longer RTs can be interpreted as the correlates of the proactive intervention over inhibitory failures. This result is consistent with Verbruggen and colleagues  who indifMRI studies have explored the neural correlates of proactive and reactive inhibitory processes. In particular, it has been reported that the proactive, differently from the reactive process, besides the Anterior Cingulate Cortex and the Insulae, recruits more subcortical structures including the Thalamus, the Midbrain and Cerebellum-Crus I ,55,56,57Along this line, we can hypothesize that the corrections measured during task performance in the present study might be due to the involvement of some of the above-mentioned subcortical structures , supportThese findings provide the first evidence on the possibility of distinguishing the inhibitory processes related to GNG and SST by classifying movement profiles as one-shot or non-one-shot based on the presence of trajectory corrections during inhibitory failures. This work added further insight to the body of the literature which reports a differentiation between these tasks and the involved cognitive control mechanisms ,62,63. AThe proactive component of response inhibition has been often evaluated by modified versions of the SST, where cues are inserted to inform subjects about the probability of an upcoming stop-signal, as in the conditional SST , or in tOther approaches have proven useful in revealing the proactive aspects of response inhibition. Namely, the reaching arm version of the stop-signal paradigm ,67 allowTo conclude, it has been shown that under proactive circumstances (GNG), erroneous responses are characterized by typical unsmooth velocity profiles. We speculate that this might be because of conflicting motor tendencies due to proactive interactions between sensorimotor reactivity and inhibition state. Another possibility might be that proactive control triggers a higher motor control level which is then engaged in correction over movement profiles.These results have been achieved thanks to a registration method capable of revealing information that typical button response systems cannot detect. For this reason, our findings may drive future studies aimed at better exploring reactive and proactive control in healthy subjects as well as in several special populations. As such, the implementation of this procedure which characterizes the movement profile of responses could allow the more thorough investigation of neurocognitive modifications in health and disease. Motor response inhibition mechanisms regulating sport expertise in athletes performing in different disciplines represents a relevant field of application . Moreove