Antarctic sedimentary successions indicate AIS expansion at 6 Ma coincident with major MSC desiccation; relative sea-level modelling indicates a prolonged ∼50 m lowstand at the Strait of Gibraltar, which resulted from AIS expansion and local evaporation of sea water in concert with evaporite precipitation that caused lithospheric deformation. Our results reconcile MSC events and demonstrate that desiccation and refilling were timed by the interplay between glacio-eustatic sea-level variations, glacial isostatic adjustment and mantle deformation in response to changing water and evaporite loads.The Messinian Salinity Crisis (MSC) was a marked late Neogene oceanographic event during which the Mediterranean Sea evaporated. Its causes remain unresolved, with tectonic restrictions to the Atlantic Ocean or glacio-eustatic restriction of flow during sea-level lowstands, or a mixture of the two mechanisms, being proposed. Here we present the first direct geological evidence of Antarctic ice-sheet (AIS) expansion at the MSC onset and use a δ About 5.6 million years ago the Mediterranean Sea evaporated leaving a 1.5 km deep basin while at the same time Antarctica's ice sheet grew. Here the authors show that growth of Antarctic ice lowered sea-level, which cut off the Atlantic Ocean from the Mediterranean Sea and allowed it to evaporate. Synchronous brine pool formation across all basins began between 5.75 and 5.60 Ma, culminating in almost complete desiccation by 5.532 Ma 1234567818O records suggested that the MSC was influenced strongly by glacioeustasy18O records and a lack of direct evidence from Antarctica demonstrating in-phase glacial variability. Previous studies of Antarctic margin successions and glacio-hydro-isostatic adjustment (GIA) modelling13Development of deep-sea benthic δWe reviewed 60 Southern Ocean and Antarctic margin sedimentary successions to reconstruct AIS evolution during the MSC. Most sites reviewed were not included because they either did not recover MSC-aged sediments or because they had insufficient chronostratigraphic control. We identified four drill sites that contain sediments indicative of ice-sheet expansion during the MSC.Ocean Drilling Program (ODP) sites 1092, 1095 and 1165  were allSediments at ODP site 1165 were recovered from a water depth of 3,537 m near the East Antarctic coastline at the boundary between the polar gyres and ACC and, critically, near the mouth of Lambert Glacier, which is the largest East AIS outlet glacier, and experienced a ca. 400-km grounding line migration during the latest Miocene16Nitzschia donahuensis, which occurs at 56.45 m below seafloor (m.b.s.f.), is calibrated at 5.8 Ma . Spectral power is greater in the magnetic susceptibility data probably because it is more sensitive to the terrigenous-to-biogenic ratio in sediments; therefore, magnetic susceptibility data were bandpass filtered to isolate the orbital signal  and Thalassiosira inura (68.61 m.c.d.), which have age calibrations of 4.73 and 4.74 Ma, respectively. We use a combination of geomagnetic reversals below the unconformityODP site 1092 comprises a succession dominated by biogenic carbonate . We refi24P′, ∼6.3 and ∼5.6 Ma The AND-1B succession  is the m3132∼34 Ma , respectively,18O to ice volume, including using isotopically heavier ice and the relatively well-understood Pleistocene isotope to sea-level calibration of 0.01‰ m−1. The calculated ice-volume fluctuations are amplified, which results in too many intervals with negative ice volume (15% of the record). The rationale for converting with isotopically heavier ice is plausible because it is likely that Miocene ice sheets were warmer and, therefore, isotopically heavier than the modern AIS , Antarctic ice-sheet thickness variations are unavailable from continuous global circulation model studies. Therefore, we reconstructed AIS volume  using be35‰ refs , 44). Hom−1 refs , 46, whim−1 refs , which r846 ref.  to ice v21 Pa s, an outer mantle viscosity of 0.5 × 1021 Pa s and an inner inviscid core. Our initial AIS is smaller than at present, so we also modified the present-day initial global topography model ETOPO1  that stem from a complex interplay between gravitational, rotational and solid Earth deformations in response to redistribution of surface ice- and water loads495051PO1 ref.  by melti18O stages TG22 through TG18, which was a prolonged period of heavy-δ18O values (∼5.75 to ∼5.67 Ma), and inferred 20–30% ice-volume increaseGeological evidence and modelling studies indicate that ice sheets often reach their greatest size immediately before a rapid ice retreat17In the deep-ocean successions assessed here , we recognize locally increased deep-current velocities after 6 Ma with eroded sediment at ODP sites 1092 and 1165, and sedimentological and AMS evidence at site 1095 for peak circulation between ca. 6.1 and 5.6 Ma , which l18O record provides strong supporting evidence for a period of AIS growth that spanned the duration of the MSC. A period of isotopic enrichment began at ca. 6.2 Ma and continued until ca. 5.75 Ma, which indicates a ca. 50% ice-volume increase that culminated in the large glaciations  during which AIS volume was probably greater than today. Our GIA sea-level simulations indicate substantial sea-level falls with a gradual base-level fall of 50–60 m between 6 and 5.6 Ma at the Gibraltar Strait (The benthic δr Strait . Sea-levr Strait  and 5a. 18O record (TG 9 and 5) indicate rapid deglaciation phases at ca. 5.48 and 5.33 Ma , open-ocean conditionsThe deglaciation phase began abruptly after ca. 5.6 Ma and isotopically light peaks in the benthic δ 5.33 Ma . At ODP  5.33 Ma . At ODP  5.33 Ma , which i∼40 m occurs between the beginning of the simulation (6.18 Ma) and 5.69 Ma in concert with numerous, short-period sea-level fluctuations above and below the Gibraltar Strait seafloor that coincide with the earliest evaporite accumulation in Mediterranean basins between 5.96 and 5.6 Ma . Accordingly, the Mediterranean Sea would have been fully connected to the Atlantic Ocean by 5.53 Ma, which is at odds with the timing of key MSC events, that is, the ‘Messinian gap' during which the Mediterranean Sea was isolated∼8 m of global sea-level rise), (iii) erosion and re-sedimentation of lower evaporites within the remaining deeper basins and (iv) deposition of upper evaporites in the deeper basins. We applied a weightless vertical barrier at 5.6 Ma to prevent any refilling caused by sea-level highstands and ran the simulation for three ice-volume scenarios (18O record (see discussion above).The GIA model indicates a r.s.l. drop at ODP site 1165 that was almost twice as large as the eustatic decrease , as a co Ma refs , 57, 58, Ma refs  and 6b, cenarios  that cor87Sr/86Sr indicates that it may have been connected with the Atlantic during the MSC with 87Sr/86Sr similar to sea water87Sr/86Sr analyses from numerous sites throughout the Mediterranean basin indicate that freshwater input was dominant67The sea-level curve that results from our reanalysis contains a major change at 5.6 Ma , where M59The next event capable of overtopping the sill was at 5.33 Ma, in agreement with the geological record and coincident with interglacial TG5 (the Zanclean flooding eventλ) were used. Bandpass filtering was performed using the Analyseries software65Data from ODP site 1165 from disturbed intervals, significant outliers and from within 8 cm of core ends were removed before spectral analysis and filtering to prevent distortion of the spectral power and filtered data. Spectral and coherency analyses were conducted on magnetic susceptibility and sediment density data  between Palaeomagnetic measurements were made on discrete samples from ODP site 1165 using a 2-G Enterprises superconducting rock magnetometer with in-line alternating field demagnetizing coils. Samples were demagnetized at 10-mT increments to fields of 80 mT, and data were visualized using the PuffinPlot software packageWe solve the SLE to compute the r.s.l. changes that accompany and follow the deposition of salts  and evaporation of Mediterranean sea water. This is done consistently (in space and time) with the ‘background' GIA signal that is dictated by our AIS chronology .−3 for the evaporites . The resulting r.s.l. changes are overlapped with the GIA signal within the SLE recursive scheme4849Lower evaporite deposition is dated at 5.96 Ma .


The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their inhibitory postsynaptic potential (IPSP) size is not uniform. Thus, cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit. The microcircuit of the neocortex is a very complex, composed of excitatory neurons , inhibitory non-pyramidal interneurons Jones, , glutama3A receptor  measured by a paired recording study of the FS basket cell and the L5 CCS pyramidal cell combined with 3D reconstruction of the synaptic junction from serial electron micrographs and simulation analysis  and protein kinase A (PKA), and by suppressing transmitter glutamate release by inhibition of presynaptic voltage-sensitive Ca2+ channels and/or by activation of K+ channels  distribution in the axon initial segment of the target pyramidal cells  values obtained with local uncaging of GABA on axon initial segment, soma and dendrite of the dentate gyrus cells of hippocampus using gramicidin-perforated patch-clamp method were −59.4 ± 1.5 mV, −65.8 ± 1.2 mV, and −70.9 ± 1.5 mV, respectively, and the intracellular levels of Cl− [Cli] calculated on the basis of the EGABA values were 11, 7.9 and 6.0 mM, respectively  and the intracellular membrane potential at each domain, and how hyperpolarization and shunting inhibitions are used within individual domains  with reference number 15A091. All surgery was performed under ketamine and xylazine, or isoflurane anesthesia, and every effort was made to minimize suffering.YK: conception and design, acquisition of data or micrographs, analysis and interpretation of data, making figure panels, drafting or revising the article. FK: making figure panels, drafting or revising the article. MN: acquisition of simulation data. YK: conception and design, drafting or revising the article.This work was supported by a Grant-in-Aid for Scientific Research , , (15K14324) and on Innovative Areas “Adaptive circuit shift (No. 3603)”  and “Prediction and decision making (No. 4303)” (26120730) of The Ministry of Education, Culture, Sports, Science, and Technology, Japan, The NOVARTIS Foundation (Japan) for the Promotion of Science.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Flos chrysanthemi indici, Buddleja officinalis, Cirsium setosum, Mentha arvensis and Buddleja davidii, and has been reported to possess analgesic, antipyretic, anti-inflammatory and neuroprotective activities. In this paper, linarin was investigated for its AChE inhibitory potential both in-vitro and ex-vivo. Ellman’s colorimetric method was used for the determination of AChE inhibitory activity in mouse brain. In-vitro assays revealed that linarin inhibited AChE activity with an IC50 of 3.801 ± 1.149 μM. Ex-vivo study showed that the AChE activity was significantly reduced in both the cortex and hippocampus of mice treated intraperitoneally with various doses of linarin . The inhibition effects produced by high dose of linarin were the same as that obtained after huperzine A treatment (0.5 mg/Kg). Molecular docking study revealed that both 4’-methoxyl group and 7-O-sugar moiety of linarin played important roles in ligand-receptor binding and thus they are mainly responsible for AChE inhibitory activity. In view of its potent AChE inhibitory activity, linarin may be a promising therapeutic agent for the treatment of some diseases associated with AChE, such as glaucoma, myasthenia gravis, gastric motility and Alzheimer’s disease.Linarin is a flavone glycoside in the plants  Acetylcholinesterase (AChE) is a substrate specific enzyme expressed in many tissues degrading neurotransmitter acetylcholine (ACh) in the nerve synapses. Inhibition of AChE is considered as a promising strategy for the treatment of some diseases caused by the too low level of ACh, such as glaucoma, myasthenia gravis, gastric motility and Alzheimer’s disease -4. NowadFlos chrysanthemi indici, Buddleja officinalis, Cirsium setosum, Mentha arvensis and Buddleja davidii. It has been reported to possess many pharmacological activities, such as analgesic, antipyretic, anti-inflammatory and neuroprotective effects  was obtained from Chengdu Must Bio-technology Co. Ltd . Huperzine A was obtained from National Institute for the Control of Pharmaceutical and Biological Products . Acetylthiocholine iodide (ATCI) and 5,5'-dithiobis-(2-nitrobenzoic acid)(DTNB) were obtained from Shanghai Ruji Bio-technology Co. Ltd . Dimethyl sulfoxide (DMSO) was purchased from Tianjin Bodi Chemical Co. Ltd . All other reagents and organic solvents were of analytical grade.Linarin .Healthy male Kunming (KM) mice, weighing 20 ± 2 g, SPF, were provided by the Laboratory Animal Center of Shenyang Pharmaceutical University . All animals were housed under standard controlled environmental conditions: temperature (25 ± 2 °C), relative humidity (60 ± 10%), room air change (12–18 times/h) and light/dark cycle (12/12). Food and water were available ad libitumIn-vitro AChE inhibition assayA blank − A sample)/( A blank − A control)× 100%, where A blank, A sample and A control are the absorbance of blank, sample and positive control, respectively. The half maximal inhibitory concentration (IC50) was calculated from the Prism  curve obtained by plotting the percentage inhibition versus the concentration of linarin.After the mice were killed by decapitation, the brains were quickly removed on an ice-cold plate and homogenized in a 10-fold volume of cold 10 mM phosphate buffer (pH 7.4). The homogenates were centrifuged at 3500 rpm for 10 min and the supernatants were employed as sources of enzyme. All the above steps were carried out at 4 °C. AChE activity was determined according to a modified Ellman assay method . BrieflyEx-vivo AChE inhibition assayThe mice were randomly divided into five groups of six mice each: normal control group, huperzine A (0.5 mg/Kg) treated group and low-, moderate-, high-dose linarin treated groups. The mice in the normal control group received an equivalent volume of 5% DMSO in saline (vehicle). All the mice were treated with a single intraperitoneal injection of the respective drugs and sacrificed 30 min later. The brains were quickly removed on an ice-cold plate, and then the cortex and hippocampi were dissected out. These tissues were homogenized in a 10-fold volume of cold 10 mM phosphate buffer (pH 7.4). The homogenates were centrifuged at 3500 rpm for 10 min and the supernatants were employed as sources of enzyme in AChE assay as described above. The percentage of inhibition was calculated by comparison with the AChE activity of mice treated with vehicle.Statistical analysesStatistical analyses were performed by using one-way analysis of variance (ANOVA) followed by Duncan’s multiple range test using the Statistical Package for the Social Sciences (SPSS) software.Molecular docking simulationx, y and z directions were constructed with a grid spacing of 0.375 Å at the center of the catalytic pocket of acetylcholinesterase. The Lamarckian Genetic Algorithm method was used for the global search for optimum binding position. After completion of docking and clustering analysis, the most favorable binding conformation with the lowest free energies was selected as the binding pose.Molecular docking simulation was performed using AutoDock 4.2. The X-ray crystal structure of acetylcholinesterase was obtained from RCSB protein data bank, which was prepared by removing both non-polar hydrogens and water molecules, and adding Kollman united-atom partial charges and solvation parameters. Meanwhile, the torsion angles of linarin were identified. A grid box of 70×70×70 points in the 50 for the inhibition of AChE by linarin was 3.801 ± 1.149 μM. Molecular docking simulation revealed that linarin was able to penetrate deeply into the catalytic site of AChE despite its large molecule length  to mice, the AChE activity in two brain regions was significantly reduced . The results indicate that linarin can inhibit AChE activity in both the cortex and hippocampus.After an intraperitoneal administration of linarin with various doses, the AChE activity in two brain regions was significantly reduced. Importantly, the inhibition effects produced by high dose of linarin (140 mg/Kg) were the same as that obtained after huperzine A treatment (0.5 mg/Kg) ( in-vitro and ex-vivo. The 4’-methoxyl group and 7-O-sugar moiety of linarin may be essential for AChE inhibition. These results help to understand the molecular basis of lianrin for AChE inhibition activity, which may be useful for rational design for anticholinesterasics and the treatment of some diseases associated with AChE in the future.In conclusion, our study demonstrates that linarin exerts a strong AChE inhibitory effect both


Ki=44 nm) with more than 50-fold selectivity over STAT5a. The binding site of the core moiety of Stafib-1 was validated by functional analysis of point mutants. A prodrug of Stafib-1 was shown to inhibit STAT5b with high selectivity over STAT5a in tumor cells. Stafib-1 provides the first demonstration that naturally occurring SH2 domains with more than 90 % sequence identity can be selectively targeted with small organic molecules.Src homology 2 (SH2) domains play a central role in signal transduction. Although many SH2 domains have been validated as drug targets, their structural similarity makes development of specific inhibitors difficult. The cancer-relevant transcription factors STAT5a and STAT5b are particularly challenging small-molecule targets because their SH2 domains are 93 % identical on the amino acid level. Here we present the natural product-inspired development of the low-nanomolar inhibitor Stafib-1, as the first small molecule which inhibits the STAT5b SH2 domain ( Src homology 2 (SH2) domains are highly homologous regions, approximately 100 amino acids long, which are found in a significant subset of signaling proteins. SH2 domains play a fundamental role in intracellular signaling via recognition of specific phosphotyrosine-containing peptide motifs. which arKi=17.4 μm).The high activity and selectivity of YLVLDKWL , derivedreceptor. Both STAs Figure . In contA key event in STAT signaling is STAT binding to activated cell surface receptors and/or non-receptor tyrosine kinases Figure .18] Bin Bin18] B13 was converted into the corresponding cell-permeable pivaloyloxymethyl (POM) ester 17, which is designed to liberate 13 inside the cell after cleavage by intracellular esterases . Treatment of Stat5b-GFP-transfected K562 cells with 17 showed a dose-dependent decrease of Tyr699 phosphorylation of STAT5b-GFP . The negative control compound 18 did not inhibit phosphorylation. Treatment of Stat5a-GFP-transfected K562 cells with 17 did not affect phosphorylation of Tyr694 of STAT5a-GFP , displays low-nanomolar activity against STAT5b (Ki=44±1 nm), with more than 50-fold selectivity over STAT5a. This is the first report describing strongly divergent affinities of the SH2 domains of STAT5a/b for a chemical entity, both in vitro and in cultured human cells. The binding site of the core of the inhibitors, catechol bisphosphate (1), on STAT5b was characterized by point mutants, which represents the first point mutant validation of a small-molecule inhibitor of a STAT SH2 domain. The pivaloyloxymethylester of Stafib-1, dubbed Pomstafib-1 (17), inhibited tyrosine phosphorylation of a STAT5b-GFP fusion protein with high selectivity over the corresponding STAT5a-GFP fusion protein in human leukemia cells. 17 will be a valuable tool for dissecting the functions of STAT5b and STAT5a in mammalian cells. To the best of our knowledge, our work represents the first demonstration that small molecules can differentiate between naturally occurring SH2 domains which have more than 90 % amino acid sequence identity. We believe that our data will significantly influence the scientific community’s perception of the potential of small molecules as potent and selective inhibitors of highly similar protein–protein interaction domains.In summary, we have developed


Distinct El Niño types have been observed in the recent decades with warmanomalies in the eastern Pacific  and centralPacific . Among these, a basinwide tropical Pacific(TP) warming is seen during 2009 and recently during 2014. We carried out dataanalysis and numerical simulation experiments to understand the possible cause fordifferent El Niño flavours. The results reveal that the co-evolution ofocean-atmospheric conditions are critically important. Stronger boreal spring(Mar-May) through summer (June-September) westerly wind anomalies (WWA), withrelatively stronger ocean pre-conditioning can lead to EL, weaker oceanpre-conditioning and weaker WWA can generate EM, while stronger oceanpreconditioning and weaker WWA can lead to basinwide warming pattern. The strengthof the WWA is crucial in determining the strength of the ocean dynamic response andthe thermocline displacements in the Pacific. The study has important implicationsfor understanding the nature of El Niño in advance. The El Niño–Southern Oscillation (ENSO) is the dominant mode ofinterannual variability in the tropical Pacific having global socioeconomic impacts1234578910111213On a different note, the similarities between the oceanic conditions in the tropicalpacific in early 2014 were similar to that in 1997, suggesting that an ElNiño matching the 1997 intensity may develop during 2014; however we seebasinwide warming pattern during boreal spring (Mar-May) and again during Septemberthrough December 2014. Since the pattern of the tropical pacific SSTA has wide impact onthe global weather and climate and different El Niño types have differentglobal teleconnections, understanding the nature and evolution of different ElNiño types is vital.A flattening of the thermocline in the equatorial Pacific caused by a weakening ofequatorial easterlies in response to global warming was suggested to be one of thereasons for the observed changes in the characteristics of El Niño events inthe recent decades71718192021The changes in the warm water volume (WWV) in the equatorial Pacific was considered to bea good indicator for the development of an El Niño16242627282730Composites of equatorial SSTA and thermocline depth (D20) anomalies  during EOn the other hand, the SST anomalies for 2014 and 2009 shaded in We note that many studies321113The distinct SST pattern during different El Niño types iscorroborated by distinct thermocline response as shown by the D20 anomalies on the dynamical response of the ocean to generate thedownwelling Kelvin waves2237383940414445−1 (as shown by thick black line) are seen inboreal spring during an EL  anomalies in theequatorial Pacific  is an important parameter related to ElNiño evolution, as discussed by Meinen & McPhadenImportantly, though the ocean pre-condition is the same for EL and TPthe zonal wind anomalies are westerly for EL and easterly for TP thus makingEL and TP evolution different. The ocean sub-surface evolution duringdifferent El Niño flavours is explored in the following section.The importance of the late boreal spring (May) wind intensity, and that of theocean pre-condition for the El Niño evolution is shown in During an EL, anomalous westerly winds generate a downwelling Kelvin wave,accompanied by anomalous surface currents that transport warmer water to theeast234749Importantly, during the 2014 TP event , eastwarTo further verify the ocean dynamic response, we have analyzed the subsurfaceconditions, in the equatorial Pacific, mixed layer and thermocline variationsduring boreal spring (MAM), boreal summer (JJA) and boreal winter (ND) as shownin In the case of the EM, the east-west thermocline slope (blue line) is close tothe climatological position (red line) during boreal spring and summer and isslightly deepened in the east during the mature phase  generatiThus, while the distinction between the EL and EM is seen in zonal currentevolution, that between the EL and TP is manifested in the thermoclinevariations.To verify and ascertain the observational conjectures we made in the previoussection relevant to anomalous evolution of the various ENSO types, in thissection, we examine the results from our Ocean General Circulation Modelexperiments (see data and Methods for details of the experiments).−2 Nm−2,The composited SSTA of EL, EM and TP during the Nov-Dec period obtained from thectl experiment, are shown in To understand the relevance and relative importance of ocean pre-condition andthe atmospheric forcing on the El Niño evolution we have performedseveral sensitivity experiments (exps1-exps5). Briefly, in the exps1, exps2 andexps3, the ocean is initialized with January 1997 ocean condition. That is, thetropical pacific is preconditioned for a strong El Niño. For thethree constituent ensembles of the exps1, the OGCM is forced with winds andshortwave and longwave fluxes from three strongest EM events  separately. In the exps2, the OGCM is forced with the 2014 and exps3 with2009 wind and fluxes respectively. The spatial pattern of SST anomalies fromthese experiments along with observed anomalies during 2014 is shown in The ensemble mean of the simulated SSTA from the exps1, along with significantvalues above 90% confidence level from a student’s two tailed t-test(contour) are shown in The anomalies of zonal wind (shaded) and wind stress (contour) are shown in Another set of experiment (exps4) has also been performed with three ensembles,each with the oceanic and atmospheric initial conditions of three strongest EMevents  separately. The ensemble mean from thesethree major EM events is shown for June-August (JJA), Sept-Oct (SO) and Nov-Dec(ND) in We have also performed exps5 with three ensembles. In each of these, the model isforced with 1997 winds i.e. a strong atmospheric forcing; But each of these, hasweak oceanic pre-condition associated with the three EM events. The ensemble means of SSTA for JJA, SO and ND are shown in The results from the sensitivity experiments reveal that strong oceanpre-condition and weak WWA will generate a TP and weak ocean condition and weakWWA will result in EM. Thus the intensity of ocean pre-condition and that of thewesterly wind anomalies are crucial for the distinct evolution of ElNiño events.Different El Niño types has been observed in the recent decades with warmanomalies in the eastern Pacific, known as canonical El Niño (EL) andwarming in the central equatorial Pacific, El Niño Modoki (EM). Amongthese, a basinwide warming pattern (TP) has been only seen during 2009 and during2014. Nonetheless, owing to the distinct basinwide warming patterns andteleconnections7In experiments carried out in this study, the ocean IC may not exactly match with thesurface forcing, which is a quintessential limitation with such sensitivityexperiments with any OGCM. Keeping this in mind, we plan to analyse long termclimate simulations with coupled GCMS, such as the CMIP5 outputs for furtherunderstanding. In addition, we also plan to carry out further sensitivityexperiments with the OGCM to explore the sensitivity of the simulated flavours tothe localization of the WWE to a particular sub-region of the tropical pacific.Keeping this in mind, we have performed a detailed analysis of observed datasets andreanalysis products to understand the possible cause. Numerical simulationexperiments have also been performed to substantiate our findings. The resultsreveal that the locations of warm SST anomalies are modulated by the intensity andseasonality of westerly wind anomalies (WWA) and ocean pre-conditioning. Relativelystronger ocean pre-conditioning and stronger boreal spring (Mar-May) to summer(June-September) westerly wind anomalies (WWA) can generate anomalously strongeast-west gradient in the equatorial thermocline anomaly which can amplifies the SSTanomalies through Bjerknes feedback during EL. Relatively weaker WWA andpreconditioning during EM, on the other hand can lead to weak east-west thermoclineslope. This facilitates the subsurface water to interact with the surface water anddamp the warming in the east. Thus, warming is primarily confined to the centralequatorial Pacific, which amplifies through surface wind convergence. During the twoTP events of 2009 and 2014, though the tropical Pacific Ocean was pre-conditionedsimilar to an EL, the lack of WWA in the western-central Pacific has likely resultedin a basinwide warming pattern.The results from our study provide an important insight about the possible cause fordistinct warming pattern during different El Niño types, and a clue inunderstanding the type of the evolving El Niño at least two seasonsahead. Given the challenges for climate models to predict the distinction betweendifferent El Niño types52et al.etal.etal.http://www.pmel.noaa.gov/tao/elnino/wwv/).The datasets used include the Met Office Hadley Centre Global Sea Ice and SeaSurface Temperature , B , and C .We distinguish the EL (EM) events based on the criteria that the amplitude of theNIÑO3 (ENSO Modoki index) index exceeds one seasonal standarddeviation for boreal summer through following boreal winterAccordingly, 1957, 1965, 1972, 1982 and 1997 are designated as the EL events and1967, 1977, 1991, 1994, 2002 and 2004 as the EM events. Owing to the distinctbasinwide warming patterns, the 2009 and 2014 events are classed as separatefrom the two known flavours. All the anomalies are computed for by subtractingthe mean for the period 1950–2014 expect for SOAD and GODAS. ForSODA (GODAS) climatology is computed for the period 1958–2008(1980–2014).et al.et al.That is the ocean initialcondition in these experiments is therefore, conducive for the developmentof a very strong El Niño such as that seen in the year1997.However, in both the exps1 and exps4, the OGCM is forced with winds and fluxesfor three strong El Niño Modoki events separately and the ensemble mean in presented in We also carry out control and sensitivity experiments with the version 4p1 of theModular Ocean Model (MOM4p1); see Griffies How to cite this article: Jadhav, J. et al. On the possible cause ofdistinct El Niño types in the recent decades. Sci. Rep.5, 17009; doi: 10.1038/srep17009 (2015).


M. tuberculosis. Here I show that serine/threonine phosphorylation sites in M. tuberculosis are highly enriched in intrinsically disordered regions, indicating similarity in the substrate recognition mechanisms of eukaryotic and M. tuberculosis kinases. Serine/threonine phosphorylation has been linked to the pathogenicity and survival of M. tuberculosis. Thus, a better understanding of how its kinases recognize their substrates could have important implications in understanding and controlling the biology of this deadly pathogen. These results also indicate that the association between serine/threonine phosphorylation and disorder is not a feature restricted to eukaryotes.Serine/threonine phosphorylation is an important mechanism that is involved in the regulation of protein function. In eukaryotes, phosphorylation occurs predominantly in intrinsically disordered regions of proteins. Though serine/threonine phosphorylation and protein disorder are much less prevalent in prokaryotes, some bacteria have high levels of serine/threonine phosphorylation and disorder, including the medically important  The reversible phosphorylation of serine and threonine residues is a widespread post-translational modification in eukaryotes, with more than a third of proteins phosphorylated during their lifetime . PhosphoOne of the most interesting findings concerning S/T phosphorylation in eukaryotes is its association with intrinsically disordered regions . IntrinsM. tuberculosis and is linked to its survival, pathogenesis and virulence . Orthologs of M. tuberculosis in mycobacteria were identified using the reciprocal best blast approach  disordered regions). I utilized the IUPred program to predict disordered regions at the proteome wide level (p 4e-12). Because longer proteins are also more likely to have long disordered regions, I tested whether phosphoproteins have higher percentage of disordered residues. Indeed, phosphoproteins have higher percentage of disordered residues than do non-phosphoproteins .Mass spectrometry based analysis previously revealed 301 phosphoproteins in on sites . First, de level . PhosphoM. tuberculosis, the phosphoresidues could be identified for 215 sites with high confidence . In 65% (49/76) of the proteins, pS/T sites were more conserved than npS/T sites from the same protein (p 0.008). Because disordered regions and disordered pS/T sites are known to evolve faster (p 0.003), whereas in 61% (14/23) of the proteins, disordered pS/T sites were more conserved than disordered npS/T sites . It is likely that the lack of higher conservation of disordered pS/T sites might be due to the low number of sites and proteins analyzed.Next, I tested whether  protein . This pre faster , I analyin vitro phosphorylation of 13-mer synthetic peptides corresponding to in vivo phosphorylation sites using different purified kinases. They could find phosphorylation of approximately half of these peptides. Based on these results, I tested whether different kinases have differential preferences for predicted disordered phosphoacceptors and found that PknA has a slightly higher preference for disordered phosphoacceptors compared with other kinases  also show an association between disorder and S/T phosphorylation, whereas bacteria with low disorder contents do not . However, when the conservation of pS/T was compared with that of npS/T from the same protein, pS/T sites were found to be more conserved relative to npS/T sites. It might be useful to prioritize pS/T sites with high conservation (relative to npS/T sites from the same protein) for further experimental studies. Phosphoproteomic analyses on more mycobacteria would also be highly valuable to identify S/T sites phosphorylated in multiple mycobacteria. In eukaryotes, disordered pS/T sites demonstrate higher rate of evolution  Are disordered and ordered S/T phosphosites functionally different? and (2) Do different kinases differ in their preferences for disorder in their substrates under physiological conditions? Incorporating disorder information might also be useful for the prediction of novel S/T phosphosites , as has rculosis . Thus, t10.7717/peerj.724/supp-1Figure S1Click here for additional data file.10.7717/peerj.724/supp-2Figure S2in vitro conditions on synthetic 13-mer peptides corresponding to in vivo phosphorylation sites  only for PknA.The phosphorylation was carried out by purified kinases under on sites . UncorreClick here for additional data file.


These allergic manifestations are believed to result from deamidated peptides in high-molecular weight fractions of Glp19S. However, relationships between the properties of HWP and its allergenicity remain unknown. Here, we experimentally assessed the cross-reactivity of IgE from Glp19S-sensitised patients' sera by examining the IgE-binding capacity to various HWPs generated under different conditions and the ability to elicit mast cell activation. We prepared three different HWP types by acidic hydrolysis (0.1M HCl treatment at 100°C), alkaline hydrolysis (1M NaOH treatment at 100°C) and enzymatic hydrolysis (Neutrase® digestion at 50°C) for 0.5, 1, 3, 6, 9, 12 and 24 h, respectively.Hydrolysed wheat protein (HWP), which has high emulsifying property and water retentivity, is added to various foods and cosmetics to improve their texture. Recently, several studies showed that a specific HWP formula could induce IgE-mediated hypersensitivity by skin contact and/or food ingestion. In Japan, a number of HWP-caused systemic wheat allergy cases were reported, including wheat-dependent exercise-induced anaphylaxis after sensitisation to acid-hydrolysed gluten additive [Glupearl 19SWe examined the capacity of IgE binding to various acid-HWPs and native gluten using Western blotting. After 0.5-1 h of acid hydrolysis, IgE immunoblotting with a patient's serum showed smears at around 40-70-kDa proteins. However, after 3 h of acid hydrolysis, IgE binding to 40-70-kDa proteins time-dependently decreased. Regarding mast cell activation by acid-HWPs, a 0.5-h hydrolysis sample showed dramatically increased mast cell activation, whereas native gluten had little effect on it. Even after prolonged hydrolysis, acid-HWPs still retained the ability to activate mast cells, with only slightly decreased activity levels. The alkaline and enzymatic hydrolysis samples are currently under investigation to assess cross-reactivity. In conclusion, we showed that allergenic HWP had specific molecular properties given by hydrolysis. These results showed that it may be possible to reduce the risk of HWP-caused allergy by the regulation of hydrolysis procedures.


Disruptions to inhibitory control are believed to contribute to multiple aspects of drug abuse, from preexisting vulnerability in at-risk individuals, through escalation to dependence, to promotion of relapse in chronic users. Paradigms investigating the suppression of actions have been investigated in animal and human research on drug addiction. Rodent research has focused largely on impulsive behaviors, often gauged by premature responding, as a viable model highlighting the relevant role of dopamine and other neurotransmitters primarily in the striatum. Human research on action inhibition in stimulant dependence has highlighted impaired performance and largely prefrontal cortical abnormalities as part of a broader pattern of cognitive abnormalities. Animal and human research implicate inhibitory difficulties mediated by fronto-striatal circuitry both preceding and as a result of excessive stimulus use. In this regard, response-inhibition has proven a useful cognitive function to gauge the integrity of fronto-striatal systems and their role in contributing to impulsive and compulsive features of drug dependence.This article is part of a Special Issue entitled SI:Addiction circuits. •Human and animal response-inhibition can inform substance dependence theorizing.•Response-inhibition difficulties contribute to impulsivity and compulsivity.•Response-inhibition can serve as a useful measure of fronto-striatal integrity. The psychological construct of response-inhibition has been applied broadly in several contexts but particularly to the psychological functions pertaining to overriding a planned action, or stopping a repetitive maladaptive behavior . Investi2prior to cocaine exposure suggests the possibility that at least some impulsivity is not simply caused by drug abuse but can also be antecedent to it .The psychological construct of response-inhibition has been influential in at least two aspects of the animal literature pertaining to the neurobiology of drug addiction. Both impulsivity and compulsivity require the notion of response-inhibition. Impulsivity can be defined as risky or premature behavior, for example when it is necessary to wait for the appropriate signal to perform a prepared response, whereas compulsivity can be defined as maladaptive preservative behavior . Drug abThe most parsimonious explanation of this deficit is that behavioral inhibition impairment is caused by a malfunctioning nucleus accumbens. However, other data indicate that the role of the nucleus accumbens in modulating this premature responding is influenced by both ‘top-down’ and ‘bottom-up’ neural influences: structures contributing to ‘top-down’ control include the infralimbic cortex and cingulate cortex  whereas The high impulsive rats also show impairments of impulsive choice; that is, they consistently choose small immediate food rewards rather than larger, delayed ones , similarThis work on impulsivity is also relevant to research on relapse, where exposure to drugs, stress or conditioned stimuli may elicit drug-taking and drug-seeking behavior . There a3The classic phenomenon is the reinstatement of drug-seeking behavior following its extinction by stress, drug primes or conditioned stimuli . The parFor drug-primed relapse in rodents, manipulations of the ventromedial PFC, such as inactivation by a mixture of GABA-A and GABA-B agonists (muscimol and baclofen), identify the prelimbic cortex to be the major controlling influence over the nucleus accumbens core, which, again, appears to be a key structure that drives the disinhibited drug-seeking behavior . MoreoveN-acetylcysteine, a cysteine pro-drug that indirectly increases extracellular glutamate  is clearly manifold. First and foremost, the symptoms manifested feature many aspects of impaired self-control and difficulties in inhibiting inappropriate behaviors. It is this loss of control that leads to persistence in drug-taking with larger amounts consumed for longer than intended, despite a desire to quit and despite adverse personal and social consequences . As noteIn accordance with such reasoning, many contemporary theories emphasize disrupted inhibitory control in drug use in combination with impulsive decision making and altered motivational and reward processes . DisruptThere is broad agreement that response-inhibition is impaired in SDI e.g., . Below wOnly a handful of papers have investigated response-inhibition in children or adolescents at risk for abuse for any substance. This is despite evidence from other paradigms of inhibitory control suggesting response-inhibition as a likely indicator of neurobiological risk for substance use disorders . In adolA more substantial body of evidence speaks to worse response-inhibition performance in SDI with a mixed pattern for response execution. . FunctioThe relatively few reported abnormalities in the striatum may seem surprising given its role in response-inhibition and in mediating addiction in animal research. However, this is likely due to fMRI studies largely utilizing tasks that do not efficiently model response execution processes separately from baseline. Future studies may consider the benefits of introducing sequences that allow more sensitive assessment of striatal involvement. Additionally, evidence for anatomical striatal abnormalities in SDI has been particularly inconclusive, possibly due to its susceptibility to individual differences in recent history of abuse and/or abstinence .Acute administration of cocaine or intravenous methylphenidate has led to improved response-inhibition performance in active or recently abstinent SDI , and occGiven that inhibitory control probably plays a role in abstinence and relapse avoidance, it is significant that abstinent SDI show less robust patterns of impairment, suggestive of possible recovery or compensation. After short term to intermediate cessation of use , response-inhibition appears impaired in some studies  but not how precisely response disinhibition may serve as a risk factor for relapse though the mediating neural structures have been reported to be modulated by abstinence (In summary, the evidence points to response-inhibition deficits accompanied by reduced PFC recruitment in current SDI that ameliorates with acute stimulant dosing, and may normalize to some degree with abstinence. This conclusion is highly consistent with evidence from other forms of cognitive control in SDI involving fronto-striatal systems . There rstinence .predate or follow stimulant abuse is unclear, though findings from at risk individuals indicate both are in play. Given the temporal evolution of addiction, it is only the difficulty of conducting longitudinal and prospective studies that has prevented their more pervasive use to help disentangle causal associations between cognition and drug use. Nonetheless, several such projects are set to shed light on how response-inhibition as part of a larger set of top-down control functions may typify stimulant use over time. Finally, it is possible that response-inhibition deficits, which progressively grow with age (Based on evidence from SDI cross-sectional studies, the degree to which neurobiological fronto-striatal abnormalities with age , may conwith age .6Relevant to the issue of the extent to which response-inhibition deficits predispose or result from stimulant dependence, are two additional lines of evidence. First, is the investigation of not only SDI but also their biological first degree siblings to detect common vulnerability markers. The notion that response-inhibition might prove a useful endophenotype, mediating genes and clinical symptoms  is plausA second line of evidence is the investigation of recreational cocaine users, loosely identified by self-reported regular cocaine use, without fulfilling DSM-IV criteria. Response-inhibition disruptions were reported in recreational users in one small study  though nTaken together, the findings elucidate how disruptions in response-inhibition contribute via multiple pathways to drug dependence. High impulsivity, manifested in part by impaired inhibition, hypothetically facilitates initial exposure and subsequent escalation, whilst elevated sensation seeking contributes only to the former. Elevated compulsivity likely contributes in parallel. Evidence that high impulsivity and to some extent compulsivity may predate drug use, is evidenced in the unaffected biological siblings . Age at 7Despite a superficially coherent picture, several issues merit discussion within the broader context of cognition and addiction models. First, chronic stimulant use has been associated with disruptions, not only in response-inhibition, but across a broad set of cognitive domains associated with fronto-striatal systems such as planning, working memory, decision-making and attention . Effect Another issue is polysubstance use, which is an inherent part of the common SDI phenotype . ResponsResponse-inhibition difficulties are also apparent across a broad spectrum of neuropsychiatric conditions . MoreoveResearch to date has not revealed a strong link between response-inhibition as measured in GNG and SST per se and OFC and vmPFC integrity, despite both regions being implicated in compulsivity  and addi8Response-inhibition is one of several complex interacting processes such as impulsive choice, altered decision making, salience attribution and motivational/reward and emotional dysregulation which contribute to the dependence phenotype . Both huHow might better understanding of response-inhibition be of relevance to treatment of SDI? From a conceptual standpoint, cognitive difficulties, although largely of medium effect size, may have pronounced consequences on daily functioning and can negatively affect treatment outcome and prevention. General inhibitory control impairments tend to be associated with poor treatment retention and increased dropout . From a Present evidence regarding neurostimulation, either via repetitive transcranial magnetic stimulation or transcranial direct current stimulation, has focused on the DLPFC circuit as a viable therapeutic procedure for improving symptoms such as craving . EvidencThe field has benefitted thus far from translational cross-species paradigms, with response-inhibition constituting a key element of the impulsivity construct. Use of such paradigms in experimental animals is highlighting a fractionation of the impulsivity construct in terms of fronto-striatal circuits  implying


Arctic amplification of global warming has led to increased summer sea ice retreat, which influences gas exchange between the Arctic Ocean and the atmosphere where sea ice previously acted as a physical barrier. Indeed, recently observed enhanced atmospheric methane concentrations in Arctic regions with fractional sea-ice cover point to unexpected feedbacks in cycling of methane. We report on methane excess in sea ice-influenced water masses in the interior Arctic Ocean and provide evidence that sea ice is a potential source. We show that methane release from sea ice into the ocean occurs via brine drainage during freezing and melting i.e. in winter and spring. In summer under a fractional sea ice cover, reduced turbulence restricts gas transfer, then seawater acts as buffer in which methane remains entrained. However, in autumn and winter surface convection initiates pronounced efflux of methane from the ice covered ocean to the atmosphere. Our results demonstrate that sea ice-sourced methane cycles seasonally between sea ice, sea-ice-influenced seawater and the atmosphere, while the deeper ocean remains decoupled. Freshening due to summer sea ice retreat will enhance this decoupling, which restricts the capacity of the deeper Arctic Ocean to act as a sink for this greenhouse gas. The Arctic is considered a region where noticeable and rapid global change is taking place and where the effects, particularly on sea ice, are dramatic, albeit that the area is relatively small globally seen12359101314Tracing this process the current study reveals a unique two stage scenario: methane release from sea ice into sea water and seasonal efflux to the atmosphere. We combine oceanographic and geochemical data and highlight new information on the impact of oceanographic processes i.e. convection and haline stratification on the geochemical behaviour of methane, especially considering the pronounced seasonality resulting in the increasing decline of summer sea ice. Our studies focus on unexpected feedbacks concerning the methane cycle in the Arctic e.g. the buffering capacity of the winter mixed layer in summer and the isolation of the deeper Arctic Ocean. The permanent isolation influences the sink capacity of the Arctic Ocean which becomes relevant for methane released by terrestrial sources in the Arctic. Hence aiming on the interaction between sea ice and sea water is fundamental and has up to now not yet been considered when it comes to understanding the balancing of trace gas fluxes in the ice covered ocean. Concerning the pronounced seasonality in trace gas fluxes our observations highlight the differences between trace gas exchanges in ice-covered Polar Regions relative to open water areas in lower latitudes.The current study is based on the analysis of concentrations, stable carbon isotope ratios and aerobic oxidation rates of methane in surface water and sea ice brine coupled with the hydrographic data along two transects in the central Arctic Ocean occupied by RV Polarstern between early August and late September 2011 (Sea ice influenced surface water encompasses the winter mixed layer (WML) and the melt water layer (MWL). The MWL comprises the upper 20 m and is formed by melting summer sea ice . The WML1314In the interior Arctic methane is super-saturated in the WML and MWL and under–saturated below the halocline in UHW (>60 m) . We sugg13C signature from the atmospheric background illustrate the strong evidence for the presence of additional sources of methane in surface water. We compare the measured data with calculated curves in order to establish whether the methane pool in seawater is modified by oxidation and mixing * ln f + (δ13CCH4)0 is used to calculate the δ13C signature of methane which results when methane is being microbially consumed  is the methane consumed by oxidation and (δ13CCH4)0 is the initial isotopic composition). RC-1 0 is −45‰ corresponding to the atmospheric δ13CCH4 value (−47‰)13C and deviates clearly from the RC-1 curve. These values are localized between RC-1 and a second Rayleigh curve 0 −75‰, i.e. the end member of methane detected in brines (blue squares). A Rayleigh curve describes ideal conditions, assuming that only one source and only one sink (oxidation) exists. The measured data have been compared with calculated curves in order to check if the methane pool in seawater is modified by oxidation. Deviations of the measured values from the calculated Rayleigh curves reflect the influence of additional processes, i.e. mixing with sources with different isotope signatures and sea-air flux. Since not only oxidation but a combination of several processes modifies the isotopic signature of methane in sea water we also displayed our data using a Keeling type plot.i.e., δconsumed .  is more depleted in 13C than methane in UHW and values scatter around an oxidation line with methane from brine as end member (Compared to the atmospheric backgroundype plot . Differed member  and 5.13C signature (−36‰ to −75‰) of methane in brine are indicative of extensive methane cycling within sea ice i.e. production and consumption, as both processes induce isotopic fractionation. Oxygen depletion in brine channels−1The large potential of sea ice to discharge methane is evident in methane super-saturation of up to 8000% in brine . FurtherMethane in sea ice may be present in two phases; dissolved in brine or most likely in small gas bubbles formed during freezing. Temperature and salinity changes lead to a sharp decrease in methane solubility, in which case a much larger amount of methane will accumulate as gas in the ice12121314In spring, methane in the ice may be released to the MWL, when basal melting starts but the top of the sea ice still remains impermeable, inhibiting direct methane release from sea ice to the atmosphere. Subsequently, sea water or melt water will flush the brine channels and gas bubbles included in the brines will re-dissolve. Several freezing and melting events may contribute to locally different levels of super saturation in the MWL  and 6.3H-CH4 tracer and with a median of 0.0009 nM/d with a 14C-CH4 tracer, respectively. Although both tracers increase ambient methane concentrations by 1.7 nM and 457 nM, respectively, an increase in uptake rate due to an increase in substrate was not observed over three days incubation. These pulse chase experiments illustrate that the abundance and activity of methanotrophic bacteria is low in the water investigated. Methanotrophs might be limited due to unfavourable growth conditions  ranges between 1.5 and 1.9 nM relative to the methane equilibrium concentration (see methods). By extrapolating the methane surplus in the top 10 m to the area of seasonal sea-ice melting  with a flame ionization detector (FID). For gas chromatographic separation we used a packed column (Porapac Q 80/100 mesh). The GC oven was operated isothermally (60 °C) and the FID was held at 250 °C. Two sets of standard gas mixtures were used for calibration. The standard deviation of duplicate analyses was 5%. This high overall error is almost exclusively due to the gas extraction procedure and not to GC precision, which had an error of only 1%. After GC analyses an aliquot of the extracted gas was transferred into pre-evacuated glass containers for analysis of the stable carbon isotopic signature on shore.We measured concentrations, stable carbon isotope ratios and aerobic oxidation rates of methane in surface water and sea ice brine along two hydrographic transects in the central Arctic Ocean occupied by RV Polarstern between early August and late September 2011. The first transect runs from 82.5°N, 50en Basin . Coverinδ13CCH4values were determined using a Delta XP plus Finnigan mass spectrometer. The extracted gas was purged and trapped with PreCon equipment (Finnigan) to pre-concentrate the sample. All isotopic ratios were given in a δ-notation relative to the Vienna Pee Dee Belemnite (VPDB) standard using conventional delta notation. The reproducibility derived from duplicates was 1–1.5‰.The 13C values (R2 = −0.84) is given for methane in UHW when y- intercept is −47‰. In sea ice-influenced water (i.e. WML and MWL) a correlation is missing when y- intercept is −47‰ (R2 = 0.0554) but given when the y- intercept is −55‰. This different correlation refers to deviating methane sources in both water masses.A significant correlation between 1/methane concentration vs. the δex situ tracer incubations in order to quantify the methane consumption. Methane oxidation rates were determined from ex situ incubations of water samples in 100 ml serum vials. Samples were incubated with 50 μl gas mixture comprised of 3H-labelled CH4 (200–300 Bq) and a second set was incubated with 10 μl of 14C-labelled CH4 (12000–15000 Bq). The samples were subsequently shaken to facilitate tracer dissolution and then incubated in the dark at 0 °C. Tracer consumption was measured after 48 h and 72 h. Incubations with 14C-CH4 were terminated by adding a 5 ml headspace and injecting 0.5 ml of 10 M NaOH so that the remaining 14C-CH4 accumulated in the headspace and the produced 14C-CO32- and 14C-biomass was trapped in the aqueous NaOH solution. Separation and activity measurement of 14C-CH4 and 14C-CO32− was carried out analogous to previous measurements of CH4 turnover in sediments14C-CH4 in the headspace was combusted to 14C-CO2, while 14C-CO32− was converted to 14C-CO2 through acidification with HCl. In either case, 14C-CO2 was then trapped and the radioactivity was measured by wet scintillation counting. Incubations with 3H-CH4: Total activity (3H-CH4 + 3H-H2O) was measured in 1 ml of sample aliquot by wet scintillation counting and activity of 3H-H2O was measured after sparging the sample for ≥30 min with nitrogen gas to remove remaining 3H-CH4. CH4 oxidation rates (rOX) were calculated assuming first order kinetics: rOX = k’ [CH4] where k’ is the effective first order rate constant calculated as the fraction of labelled CH4 oxidized per unit time and [CH4] is the ambient CH4 concentration. Killed controls resulted in methane oxidation rates near zero.Water was sampled directly from the ice floes through ice core holes for How to cite this article: Damm, E. et al. Methane excess in Arctic surface water-triggered by sea ice formation and melting. Sci. Rep.5, 16179; doi: 10.1038/srep16179 (2015).


In all living organisms, the phosphorylation of proteins modulates various aspects of their functionalities. In eukaryotes, protein phosphorylation plays a key role in cell signaling, gene expression, and differentiation. Protein phosphorylation is also involved in the global control of DNA replication during the cell cycle, as well as in the mechanisms that cope with stress-induced replication blocks. Similar to eukaryotes, bacteria use Hanks-type kinases and phosphatases for signal transduction, and protein phosphorylation is involved in numerous cellular processes. However, it remains unclear whether protein phosphorylation in bacteria can also regulate the activity of proteins involved in DNA-mediated processes such as DNA replication or repair. Accumulating evidence supported by functional and biochemical studies suggests that phospho-regulatory mechanisms also take place during the bacterial cell cycle. Recent phosphoproteomics and interactomics studies identified numerous phosphoproteins involved in various aspect of DNA metabolism strongly supporting the existence of such level of regulation in bacteria. Similar to eukaryotes, bacterial scaffolding-like proteins emerged as platforms for kinase activation and signaling. This review reports the current knowledge on the phosphorylation of proteins involved in the maintenance of genome integrity and the regulation of cell cycle in bacteria that reveals surprising similarities to eukaryotes. In all living cells, many cellular processes are controlled through the reversible phosphorylation of proteins on serine, threonine and tyrosine (Ser/Thr/Tyr) which results from the opposing action of kinases and phosphatases. While the role of Ser/Thr and Tyr -protein kinases (STYKs) and phosphatases in cellular regulations is extensively documented in eukaryotes, the Ser/Thr/Tyr signaling network in bacteria has a more recent history Hunter, . AnalysiBacillus subtilis by three Ser/Thr kinases, PrkC, PrkD, and YabT, leads to the deregulation of numerous target genes during the transition of vegetative to stationary growth  are histone-like proteins involved in modifying the structural organization of chromosomes by changing its topology at a global or local level  having an active role in signaling while being itself devoid of catalytic activity relevant for signaling, and (ii) being able to promote the interaction of multiple components of signaling cascades at a particular cellular location to regulate their activity , suggesting a potential ability to bring various components of tyrosine, but also serine/threonine phosphorylation pathways in close proximity -mediated control of FtsZ assembly during vegetative growth, to a RacA mediated chromosome anchorage to the pole of the fore spore compartment at the onset of sporulation  to MN and IM and the Vetenskapsrådet (2015-05319) and the Novo Nordisk Foundation to IM. TG is supported by the European Union, Marie Curie ITN AMBER, 317338.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


These data suggest pathophysiological significance of mGluR2 signaling in PNS and its possible therapeutic importance to combat demyelinating disorders including Charcot-Marie-Tooth disease.Rapid saltatory nerve conduction is facilitated by myelin structure, which is produced by Schwann cells (SC) in the peripheral nervous system (PNS). Proper development and degeneration/regeneration after injury requires regulated phenotypic changes of SC. We have previously shown that glutamate can induce SC proliferation in culture. Here we show that glutamate signals through metabotropic glutamate receptor 2 (mGluR2) to induce Erk phosphorylation in SC. mGluR2-elicited Erk phosphorylation requires ErbB2/3 receptor tyrosine kinase phosphorylation to limit the signaling cascade that promotes phosphorylation of Erk, but not Akt. We found that Gβγ and Src are involved in subcellular signaling downstream of mGluR2. We also found that glutamate can transform myelinating SC to proliferating SC, while inhibition of mGluR2 signaling can inhibit demyelination of injured nerves  Rapid saltatory conduction of electrical signals along the distance of an axon is facilitated by myelin, a lipid-rich ionic insulator that wraps around the axon1Signaling that translates humoral/contact-mediated stimulation to SC differentiation has been thoroughly examined to better understand the mechanism of myelination in the PNS. Neuregulin-1 (Nrg1)-ErbB2/3 signal is known to play a major role in SC differentiation and proliferation. SC precursors that associate with peripheral axons express the tyrosine kinase receptors ErbB2/3589in vivo situations. Nrg1 may be the most well-characterized and only example of such molecule that can elicit multiple SC intracellular signaling pathways, but the knowledge with regard to the molecular mechanism to coordinate these multiple events in SC is still limited.It has become increasingly clear that the undifferentiated/differentiated phenotypes of SC are tightly regulated by a cascade of intracellular signaling events, and an orchestrated series of gene expression pathways of regulatory proteins and molecules found on the cell surface and extracellular matrix13in vitro myelination experiments that increased glutamate concentration inhibited myelination and yet promoted SC proliferation by activating metabotropic glutamate receptor (mGluR) signaling. GS expression decreases glutamate concentration, and thereby promotes myelinationin vivo. Our data suggest that controlling glutamate levels in peripheral nerve is crucial for SC proliferation, as well as differentiation.We previously reported that expression of glutamine synthetase (GS) in SC promotes their myelination phenotype. GS is an enzyme that catalyzes conversion of glutamate into glutamine. We previously showed by using in vitro, and that glutamate along with an mGluR agonist promotes SC proliferation. These data suggested that glutamate affects the differentiation status of SC via mGluR on SC. To show that the myelination-promoting effect of GS expression in SC is mediated by mGluR signaling, we first examined the effects of mGluR inhibitors on SC myelination and glutamate-induced SC proliferation in vitro. We found that application of PCCG-4, an mGluR2/3 antagonist, significantly promoted myelination to an extent similar to GS overexpression in SC  responsible for signaling. For this purpose, we examined mRNA expression of mGluR family members by RT-PCR. We found that mGluR2 showed detectable mRNA expression in primary cultured SC  or MPEP (an mGluR5 antagonist) . These dmGluR2 is known to elicit intracellular signaling by association with Gi proteins. Ligand-bound mGluR2 activates heterotrimeric Gαβγ proteins by exchanging GDP (bound to the Gα) for GTP, which leads to dissociation of GTP-bound Gα from Gβγ. The Gαi subunit inhibits adenylyl cyclase, and thereby decreases intracellular cAMP. The Gβγ subunits, after dissociation from Gαi subunits, also act as a signaling molecule to induce Erk phosphorylationPrevious reports have shown that intracellular signaling molecules downstream of Gβγ include Src and PI3K. To uncover the involvement of Src and PI3K in glutamate-elicited signaling in SC, we examined glutamate-induced Erk phosphorylation in the presence of Src and PI3K inhibitors1920In SC, promotion of the differentiated phenotype is strongly associated with inhibition of the proliferation/de-differentiation phenotype; and the same is true for inhibition of differentiation and promotion of proliferation/de-differentiation7810To examine the phenotypic consequence of the Krox20 increase, we performed luciferase reporter assay using SC with mGluR2 down-regulation, to evaluate the transcription status of myelin basic protein (MBP), whose expression is critically important for the myelinating SC phenotype. We found increased transcription of MBP in SC with mGluR2 down-regulation . Furtherin vitro myelination assay using an mGluR2/3 antagonist and mGluR2 down-regulation , it is also important as an excitatory neurotransmitter. In the CNS, astrocytes which express GS serve to terminate glutamatergic transsynaptic signaling by uptaking glutamate released from synaptic terminals26277The ErbB2/3 receptor complex can transmit multiple signaling in SC. ErbB2/3 on SC usually takes Nrg1 as a ligand and can associate with a variety of molecules in the SC cytoplasm, which transmit different signals leading to multiple phenotypic consequences57in vitroin vivo settings compared with apparent induction capability of Erk phosphorylation in vitro. Another possibility is that Nrg1 is continuously produced and always present at low level in physiological peripheral nerves, and so therefore glutamate can always exert strong effects in vivo despite its effect on cultured SC in vitro.We show here that glutamate application on normal sciatic nerve can induce de-differentiation of myelinating SC to initiate proliferation. We have shown previously that forced expression of GS in primary cultured SC promotes myelination We showed here that inhibition of mGluR2 signaling in SC not only promotes myelination, but also prevents demyelination. This effect may be relevant for therapeutic application of the mGluR2 inhibition against demyelinating disorders in PNS, such as Charcot Marie Tooth disease type 1 (CMT1). CMT is one of the most common genetic disorders, affecting one out of every 2500 people, and causes severe motor and sensory deficits resulting in significant patient morbidity and mortality, but no treatment against CMT exists thus far3538The experimental procedures performed on mice and rats were carried out in accordance with the approved guidelines from the Ministry of Health, Labor and Welfare of Japan. The experimental protocol was approved by the Animal Welfare Committee in the National Center of Neurology and Psychiatry.Sciatic nerves of eight- to eleven-week old mice were treated with glutamate or PBS using collagen-gel matrices, Gelfoam (Pfizer) for 3 days. Sciatic nerve transection experiments were performed as previously describedin vivo effects of reagents, mGluR2/3 antagonist -2-(2′-carboxy-3′-phenylcyclopropyl)glycine  and mGluR5 antagonists 6-Methyl-2-(phenylethynyl)pyridine  were administered locally using Gelfoam around sciatic nerves of 8 to 11 week old mice for 4 days prior to collection for histological analysis.For analysis of His-tagged Gβ1 (His-Gb1) and His-Gγ2 expression vectors were generated by amplifying the full-length coding region of the Gβ1 cDNA (GenBank accession number NM_030987) and Gγ2 (GenBank accession number NM_031754); and then cloned into pcDNA4-His MAX at the EcoR I site. The integrity of the clones was verified by nucleotide sequence analysis. Luciferase reporter plasmid MBP-luc was a gift from Dr. Lawrence Wrabetz. CMV-Renilla.luciferase was purchased from Promega.For cosmid vector construction, His-tagged Gβ1 and Gγ2 were cloned into the pAxCALNLwtit2 cosmid vector (Takara Bio). Recombinant adenovirus was generated using the Takara adenovirus expression kit following the manufacturer’s instructions. The purification and concentration of adenoviral vectors were carried out by cesium chloride density gradient centrifugation and Centricon Centrifugal Filter Devices (Millipore). Viral titres were determined with a plaque-forming assay in HEK293 cells as previously describedPrimary SC cultures were prepared as described previouslymGluR antagonists were applied to the cultures at following concentrations: mGluR1 antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid , mGluR2/3 antagonists PCCG-4 (100 μM) and mGluR5 antagonist MPEP (10 μM). In some experiments, SC were treated with NF023, a Gαi inhibitor, at 10 μM, Gβγ Modulator II, Gallein (Millipore) at 400 nM, dibutyryl cyclic AMP (dbcAMP) at 1 mM, ErbB2 inhibitor PKI166 (a gift from Novartis) at 200 nM.For analyzing Erk phosphorylation status, SC were serum-starved with 1% FBS DMEM for 6 hours, followed by 1% FBS DMEM containing Nrg1 and indicated reagents for 30 min.For proliferation analysis, SC were treated with 2 mM glutamate, together with indicated mGluR antagonists for 24 h later. EdU (20 μM) was added 2 h before fixation for detection by Click-iT EdU Imaging Kit (Invitrogen). Quantification of proliferating cell number was performed by counting the number of Edu-labeled cells under microscope in four randomly selected fields per each condition using 5x objective lens.For reporter assays, the SC were transfected with MBP- firefly luciferase and CMV- Renilla luciferase using the NEPA21 electroporator . After transfection, Schwann cells were cultured for 3 days before harvesting for luciferase activity measurement using dual luciferase assay kit (Promega).Cells were washed and lysed with lysis buffer containing 50 mM Tris-HCl, pH8.0, 150 mM NaCl, 1% NP-40, 0.5% DOC, 0.1% SDS. The lysate was subject to SDS-PAGE and immunoblot analysis with a standard procedureTotal RNA was isolated from indicated cells using RNeasy MiniKit (Qiagen), and first-strand cDNA was obtained with SuperScript III, according to the manufacturer’s protocol (Invitrogen). PCR was performed using LA Taq (Takara Bio) with the following primer sets: mGluR1, 5′-GGAATGGTACGATCTGTGTG-3′, 5′-CCACTCAAGATAACGGACAG-3′; mGluR2, 5′-CACCTGCATCATCTGGCTGGC-3′, 5′-GGGATCCAGACCCTTGAC-3′; mGluR3, 5′-CCTCAACAGGTTCAGCGTCAG-3′, 5′-TGTGAGCACTTTGTCTAACAG-3′; mGluR4, 5′-ACAGTCAGCCGACAAGCTGTACAT-3′, 5′-ATGGTTGGTGTAGGTGACGTAGGT-3′; mGluR5, 5′-GATCCAGCAGCCTAGTCAAC-3′, 5′-GTCGCTGCCACAAATGTTGC-3′; mGluR6, 5′-GAGGTGTGCCTGAGACCTTC-3′, 5′-GCTCAGTGACACAGTTAGTG-3′; mGluR7, 5′-CATGTCATCAAGGCTGTCAC-3′, 5′-GGAACAGGTTAGATAACCAG-3′; mGluR8, 5′-CAATGTACACCACGTGCATC-3′, 5′-CATTCCCAGAGACACTGAAG-3′. GAPDH, 5′-ACAAAATGGTGAAGGTCGGTGTGA-3′, 5′-AGCTTCCCATTCTCGGCCTTGAC-3′; S100b, 5′-TGGTTGCCCTCATTGATGTCT-3′ 5′-CCCATCCCCATCTTCGTCC-3′; Brn3a, 5′-CAGGAGTCCCATGTAAGA-3′, 5′-ACAGGGAAACACTTCTGC-3′.Real time quantitative PCR (qRT-PCR) was performed on the ABI Prism 7300 System (Applied Biosystems) as previously describedIn vitro myelination assays were performed as described previouslyt test. All data are reported as mean ± SD; p value of less than 0.05 is considered significant.t test. All data are reported as mean ± SD; p value of less than 0.05 is considered significant.Immunohistochemistry was performed as previously described15Toluidine blue staining of nerve samples was performed as previously describedFor electron microscopic analysis, mice were perfusion fixed transcardially with 2% paraformaldehyde and 2.5% glutaraldehyde in PBS. Fixed sciatic nerves were removed and embedded in 3% agarose in PBS. Transverse sections (150 um thickness) were prepared by using a Microslicer , and the sections of the location 3 mm distal to the transected site were selected under microscopic observation. The selected sections were rinsed, osmicated, dehydrated, and embedded in epoxy resin. Ultrathin sections were prepared, stained with lead citrate and uranyl acetate, and observed under a transmission electron microscope .How to cite this article: Saitoh, F. et al. Glutamate signals through mGluR2 to control Schwann cell differentiation and proliferation. Sci. Rep. 6, 29856; doi: 10.1038/srep29856 (2016).


Ursus maritimus) of the SB have mostly remained on the sea ice year-round (except for those that came ashore to den), but recent changes in the extent and phenology of sea ice habitat have coincided with evidence that use of terrestrial habitat is increasing. We characterized the spatial behavior of polar bears spending summer and fall on land along Alaska’s north coast to better understand the nexus between rapid environmental change and increased use of terrestrial habitat. We found that the percentage of radiocollared adult females from the SB subpopulation coming ashore has tripled over 15 years. Moreover, we detected trends of earlier arrival on shore, increased length of stay, and later departure back to sea ice, all of which were related to declines in the availability of sea ice habitat over the continental shelf and changes to sea ice phenology. Since the late 1990s, the mean duration of the open-water season in the SB increased by 36 days, and the mean length of stay on shore increased by 31 days. While on shore, the distribution of polar bears was influenced by the availability of scavenge subsidies in the form of subsistence-harvested bowhead whale  remains aggregated at sites along the coast. The declining spatio-temporal availability of sea ice habitat and increased availability of human-provisioned resources are likely to result in increased use of land. Increased residency on land is cause for concern given that, while there, bears may be exposed to a greater array of risk factors including those associated with increased human activities.In the Arctic Ocean’s southern Beaufort Sea (SB), the length of the sea ice melt season  has increased substantially since the late 1990s. Historically, polar bears ( Ursus maritimus) is linked to the health of the Arctic marine ecosystem, particularly the availability of sea-ice habitat [The long-term persistence of polar bears . As a rPolar bears of the southern Beaufort Sea (SB) subpopulation have historically spent the entire year on the sea ice , even when the pack ice retreated away from the coast to its minimal extent in September , 13. HowHere, we investigated polar bears from Alaska’s SB subpopulation, where rapid environmental change may be driving a divergence in space use and foraging behaviors in the form of increased land use. Specifically, our objectives were to examine (i) the long-term trend in the use of terrestrial habitat, (ii) the influence of sea ice characteristics on the phenology of movement from sea ice to terrestrial habitats and back to ice, and (iii) the spatial distribution of bears while on shore. Last, we discuss potential cascading effects of behavioral divergence and how those effects may influence population dynamics in the SB through time.This research was approved under the Marine Mammal Protection Act and Endangered Species Act with U.S. Fish and Wildlife Service (USFWS) permit number MA690038. Capture protocols were approved by the U.S. Geological Survey (USGS) Institutional Animal Care and Use Committee.The study area ranged from Baillie Island, Canada,  in the east, to Point Barrow, USA,  in the west . The SB Balaena mysticetus) in the fall: Barrow, Nuiqsut, and Kaktovik. Remains from the harvest have been sporadically aggregated at Point Barrow and consistently aggregated at Cross Island and Barter Island, all of which are nearly evenly spaced along the coast where they have served as focal attractors for polar bears [The SB coastal region is characterized by an industrial footprint associated with oil and gas exploration and extraction activities causing polar bears that frequent this area to be potentially exposed to industrial activities . The Pruar bears .®, Fort Dodge and Warner-Lambert Co.) using a projectile syringe fired from a dart gun. A subset of adult females was fitted with either Argos or global positioning system (GPS) Platform Transmitter Terminal (PTT) satellite radio collars [Polar bear research in the SB has been ongoing for over 30 years, and we used both historical and contemporary data sets to investigate whether use of land has changed over time. Since the mid-1980s, polar bears have been captured on the sea ice (up to 160 km from the coast) nearly every spring. Polar bears were encountered opportunistically from a helicopter and immobilized with the drugs sernylan or phencyclidine (prior to 1987) and tiletamine hydrochloride plus zolazepam hydrochloride . We filtered locations in an attempt to remove spurious locations by first removing all designations which had a high probability of being erroneous. We then applied the Douglas Argos-Filter algorithm [We used location data from radiocollared adult females from 1986 to 2014 to determine if bears used terrestrial habitat during summer and, if so, to generate estimates of mean date of arrival on shore, duration of time spent on shore, and mean date of departure from shore back to the sea ice. The majority of locations prior to 2010 were derived with the Argos System, and have variable levels of accuracy from < 250 m to > 1500 m (see lgorithm  using a http://www.telonics.com/technotes/argosintro.php). Because location accuracies are not provided for locations with LA or LB designations, we provided conservative location accuracies; LA: 5,000 m, LB: 10,000 m. We assigned locations obtained from GPS collars an accuracy of 30 m.To integrate the GPS and filtered Argos location data, which varied both in accuracy and the temporal scale of collection, we employed the continuous time correlated random walk (CRAWL) model  to develBased on the observed location accuracy and land use, we used the R  package http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS301; accessed 12 Aug 2014) for the North Slope of Alaska. While this layer covered the majority of land used by bears in this study, it did not provide coverage for eastern Canada. Thus, to account for land use in that region, we used the default continent shapefile found in ArcGIS . Because neither land coverage had sufficient resolution to detect small barrier islands, which are known to receive significant use by polar bears during summer [We determined if an animal’s location occurred on land by overlaying locations on one of two land coverages. The first layer was a digital elevation model  with a binomial distribution to determine whether the percentage of radiocollared polar bears using land ≥21 consecutive days versus remaining on the sea ice changed over time. We chose the threshold of ≥21 consecutive days because it has been used previously , 38 to dTo determine the relationship between the phenology of onshore use by radiocollared bears and sea ice dynamics, we used linear mixed models to examine the influence of sea ice conditions and characteristics on the annual mean timing of arrival on shore, length of stay on shore, and timing of departure from shore back to the sea ice. For this analysis, we included bears that came ashore for ≥7 consecutive days and used ordinal dates of arrival and departure, and total days spent on shore as response variables. We used the ≥7 consecutive days threshold to exclude bears that used land incidentally. Because we sampled some of the same individuals repeatedly, we included individual identity as a random factor in the models with first-order autocorrelation as a covariance structure. We used restricted maximum likelihood (REML) methods for model estimation. When modeling timing of departure, we censored individuals that entered maternity dens on land. Predictor variables included measures of >15% and >50% sea ice concentrations over the continental shelf , distance from the shelf of >15% and >50% sea ice , and length of the open water season defined as the periods of time when sea ice concentration remained ≤15 or ≤50% .a priori, sets of biologically plausible candidate models (c) to aid in determining top models. We used AICc to rank and compare models based on ΔAICc and normalized Akaike weights wi and considered models with ΔAICc values >2.0 to measurably differ in information content [c values [We developed, e models  and used content . When fac values . Followic values , we consc values . We usedc values .We used the paired sets of annual aerial surveys to investigate whether the availability of bowhead whale remains influenced polar bear distribution. We pooled data among years from surveys conducted before and after whale remains were placed at carcass aggregation sites . We used Moran’s I statistic to test the hypothesis that polar bear sightings were spatially autocorrelated  and an ArcGIS to determine the Euclidean distance of each bear sighting to the closest carcass aggregation site. We then used a Kolmogorov-Smirnov test to determine if the distribution of distances from carcass sites differed between survey sessions― i.e., whether the spatial distribution of bears differed prior to and after the stocking of carcass sites. Statistical significance for these tests was set at α = 0.05.year = 0.58, P = 0.004). Using piecewise regression, we detected a breakpoint in the percentage of radiocollared bears on shore for ≥21 days at the year 2000: the average percentage of bears on shore increased from 5.8% (SE = 0.02) during 1986–1999 to 20% (SE = 0.03) during 2000–2014, reaching a high of 37% in 2013 , SE = 3.9; 2000–2014 = 241 , SE = 3.1), ranging from 6 August in 1993 to 22 July in 2000. From 1986–1999, the mean length of stay on shore was 20 days (SE = 2.5 days); from 2000–2014, the mean length of stay on shore was 56 days (SE = 3.2 days). Date of departure also varied over the years, ranging from 14 August in 1993 to 7 November in 2013 , SE = 5.3; 2000–2013 = 294 , SE = 1.6).Among all data, 68 radiocollared  bears representing 46 individuals spent ≥7 days shore during the open water season, which were used to characterize onshore phenology. The piecewise regression indicated that the earliest date of arrival on shore by radiocollared bears differed between the two periods  and the proportion of the shelf covered by >15% concentration sea ice the week prior to arrival on shore  . Examinac > 2 .61,14 = 8.90, P < 0.0001; c >2 , duration of the open water season , and year  . Examina01; c >2 .c >2 , the mean distance of >15% sea ice concentration from the shelf , and year  . The 85%c >2 . Inspectthe data . Over thMoran’s I statistic indicated that polar bears were not randomly distributed when observed during aerial surveys conducted prior to  use of terrestrial habitat during the open-water season by SB polar bears was relatively rare and limited to short durations . RecentlThe relatively infrequent historical use of land by SB polar bears was likely due to the persistent availability of sea ice over the continental shelf, even during the period of minimum sea ice extent in September. Since the late 1990s, the duration of the open-water season in the SB increased by an average of 66% or 82% (depending on sea ice concentration threshold), while the September average distance from shore to pack ice increased by 120%. Since the 2000s, the length of the open-water season has increased at a rate of ≈9 days/decade, which is among the largest rates of increase for the seas of the Arctic Ocean . From 20Previous work in the SB  and elseParus major) to closely track changes in prey phenology and maintain the temporal match between clutch hatch date and peak availability of prey. This suggests that behavioral adjustments that closely track key phenological shifts may lessen some impacts of rapid environmental change, at least in the short term. The decision by some polar bears from the SB to exploit terrestrial habitat, rather than remain with the retreating pack ice, appears to be a behavioral response to the loss of sea ice habitat over the continental shelf. This behavior is not necessarily surprising since other subpopulations where the sea ice completely melts every summer  display greater use of land along with flexibility in foraging behavior [Ursus arctos) [We found a notable increase in the proportion of radiocollared bears coming ashore in summer and fall beginning in the year 2000. From 2004 to 2007, there was a pronounced decline in the survival of SB polar bears, followed by two years (2008–2009) of apparent stability . The decbehavior . In the  arctos) , and inc arctos) . However arctos) .Distribution data obtained from aerial surveys suggests that bowhead whale bone piles are focal attractors for bears on shore. Rogers et al.  found evst century [Increased use of terrestrial habitat and exploitation of human-provisioned resources by polar bears has attendant risks, including a greater potential for human-polar bear interaction and conflict. Wildlife-human conflict can have wide-ranging effects, including adversely impacting wildlife populations, causing economic losses to stakeholders, and endangering public safety . The nor century , terrest century ), and thPusa hispida) and bearded seals (Erignathus barbatus), which may explain reports of increased frequency of fasting, decreased kill rates [Our study suggests that SB polar bears have become more reliant on terrestrial habitat. Since the mid-2000s, the estimated proportion of the SB subpopulation coming ashore  has incrll rates , 67, andll rates . By contPolar bears have evolved preferences for sea ice habitat and preying on marine mammals. In the SB, those preferences are informing two seemingly disparate strategies for coping with the loss of summer sea ice habitat: displace to shore and scavenge on predictably-available marine mammal food, or remain with the sea ice as it retracts over the polar basin and risk nutritional restriction . Human-iS1 Table(DOCX)Click here for additional data file.