bluuebunny/crossref_metadata_2025_split huggingface dataset:
General lack of structural characterization of chemically synthesized long peptides
Authors: Boutin Jean A. , Tartar André L. , van Dorsselaer Alain , Vaudry Hubert 
Published: March 2019

AbstractMany peptide chemistry scientists have been reporting extremely interesting work on the basis of chemical peptides for which the only characterization was their purity, mass, and biological activity. It seems slightly overenthusiastic, as many of these structures should be thoroughly characterized first to demonstrate the uniqueness of the structure, as opposed to the uniqueness of the sequence. Among the peptides of identical sequences in the final chemical preparation, what amount of well‐folded peptide supports the measured activity? The activity of a peptide preparation cannot prove the purity of the desired peptide. Therefore, greater care should be taken in characterizing peptides, particularly those coming from chemical synthesis. At a time when the pharmaceutical industry is changing its paradigm by moving substantially from small molecules to biologics to better serve patients' needs, it is important to understand the limitations of the descriptions of these products and to start to apply the same “good laboratory practices” to our peptide research. Here, we attempt to delineate how synthetic peptides are described and characterized and what will be needed to describe them in regards to how they are well‐folded and homogeneous in their tertiary structure. Older studies were done when the tools were not yet discovered, but more recent publications are still lacking proper descriptions of these peptides. Modern tools of analysis are capable of segregating folded and unfolded peptides, even if the preparation is biologically active.
Go your own way: Exploring the causes of top executive turnover
Authors: Andrus Joel L. , Withers Michael C. , Courtright Stephen H. , Boivie Steven 
Published: March 2019

Research SummaryWhy do top executives leave their firms? Research on executive turnover has either focused on CEO dismissal or on group‐level top management team (TMT) departure rates, mostly ignoring individual‐level factors that would predict why non‐CEO executives exit. Here, we extend the shock perspective of the unfolding model of turnover used in organizational behavior research to show how relational and reputational shocks influence turnover at the executive level. Our sample includes over 4,000 executives from S&P 1500 firms over 11 years. We hypothesize and find that relational and reputational shocks increase the likelihood of top executive exit. We also consider the moderating influence of pay disparity on these relationships, which impacts how each type of shock influences executive turnover.Managerial SummaryReplacing top executives can be extremely costly for firms. Consequently, understanding the reasons behind top executive exit are important. We examine the effect of different types of shock on the likelihood a top executive will exit their firm. We find that both relational shocks (e.g., other members of the TMT leaving), as well as reputational shocks (e.g., litigation or shareholder activism against the firm), increase turnover. However, we find that higher status executives experience these shocks differently than lower status executives.
LASP: Fast global potential energy surface exploration
Authors: Huang Si‐Da , Shang Cheng , Kang Pei‐Lin , Zhang Xiao‐Jie , Liu Zhi‐Pan 
Published: March 2019

Here we introduce the LASP code, which is designed for large‐scale atomistic simulation of complex materials with neural network (NN) potential. The software architecture and functionalities of LASP will be overviewed. LASP features with the global neural network (G‐NN) potential that is generated by learning the first principles dataset of global PES from stochastic surface walking (SSW) global optimization. The combination of the SSW method with global NN potential facilitates greatly the PES exploration for a wide range of complex materials. Not limited to SSW‐NN global optimization, the software implements standard interfaces to dock with other energy/force evaluation packages and can also perform common tasks for computing PES properties, such as single‐ended and double‐ended transition state search, the molecular dynamics simulation with and without restraints. A few examples are given to illustrate the efficiency and capabilities of LASP code. Our ongoing efforts for code developing and G‐NN potential library building are also presented.This article is categorized under:

Software > Simulation Methods
Analytic result for the nonplanar hexa-box integrals
Authors: Chicherin D. , Gehrmann T. , Henn J. M. , Lo Presti N. A. , Mitev V. , Wasser P. 
Published: March 2019

AbstractIn this paper, we analytically compute all master integrals for one of the two non-planar integral families for five-particle massless scattering at two loops. We first derive an integral basis of 73 integrals with constant leading singularities. We then construct the system of differential equations satisfied by them, and find that it is in canonical form. The solution space is in agreement with a recent conjecture for the non-planar pentagon alphabet. We fix the boundary constants of the differential equations by exploiting constraints from the absence of unphysical singularities. The solution of the differential equations in the Euclidean region is expressed in terms of iterated integrals. We cross-check the latter against previously known results in the literature, as well as with independent Mellin-Barnes calculations.
Small and Laterally Placed Incisional Hernias Can be Safely Managed with an Onlay Repair
Authors: Schrittwieser Rudolf , Köckerling Ferdinand , Adolf Daniela , Hukauf Martin , Gruber‐Blum Simone , Fortelny René H. , Petter‐Puchner Alexander H. 
Published: March 2019

AbstractIntroductionIn meta‐analyses and systematic reviews, clear advantages have been identified for the sublay versus onlay technique for treatment of incisional hernias. Nonetheless, an expert panel has noted that the onlay mesh location may be useful in certain settings.Materials and methodsFirst, unadjusted analysis of data from the Herniamed Registry was performed to compare 6797 sublay operations with 1024 onlay operations for repair of incisional hernias. Then, using propensity score matching to account for the influence of variables age, gender, ASA score, BMI, risk factors, preoperative pain, defect size, and defect localization, 1016 pairs were formed and compared with each other.ResultsUnadjusted analysis revealed that the onlay operation was used significantly more often for small defects, lateral defect localization, and in women. After comparing the propensity score‐matched pairs, no significant difference was found between the sublay and onlay technique in the outcome criteria intra‐ and postoperative complications, general complications, complication‐related reoperations, pain at rest, pain on exertion, chronic pain requiring treatment, and recurrence on 1‐year follow‐up. But that was true only for this carefully selected patient collective.ConclusionIn a selected patient collective with small and lateral incisional hernias and with a large proportion of women, outcomes obtained for the onlay and sublay techniques do not differ significantly.
Synthesis and Characterization of a Silica-Based Drug Delivery System for Spinal Cord Injury Therapy
Authors: Sun Guodong , Zeng Shenghui , Liu Xu , Shi Haishan , Zhang Renwen , Wang Baocheng , Zhou Changren , Yu Tao 
Published: March 2019

Abstract
Acute inflammation is a central component in the progression of spinal cord injury (SCI). Anti-inflammatory drugs used in the clinic are often administered systemically at high doses, which can paradoxically increase inflammation and result in drug toxicity. A cluster-like mesoporous silica/arctigenin/CAQK composite (MSN-FC@ARC-G) drug delivery system was designed to avoid systemic side effects of high-dose therapy by enabling site-specific drug delivery to the spinal cord. In this nanosystem, mesoporous silica was modified with the FITC fluorescent molecule and CAQK peptides that target brain injury and SCI sites. The size of the nanocarrier was kept at approximately 100 nm to enable penetration of the blood–brain barrier. Arctigenin, a Chinese herbal medicine, was loaded into the nanosystem to reduce inflammation. The in vivo results showed that MSN-FC@ARC-G could attenuate inflammation at the injury site. Behavior and morphology experiments suggested that MSN-FC@ARC-G could diminish local microenvironment damage, especially reducing the expression of interleukin-17 (IL-17) and IL-17-related inflammatory factors, inhibiting the activation of astrocytes, thus protecting neurons and accelerating the recovery of SCI. Our study demonstrated that this novel, silica-based drug delivery system has promising potential for clinical application in SCI therapy.
Immediate and delayed decrease of long term potentiation and memory deficits after neonatal intermittent hypoxia
Authors: Goussakov Ivan , Synowiec Sylvia , Yarnykh Vasily , Drobyshevsky Alexander 
Published: March 2019

AbstractApnea of prematurity is a common clinical condition that occurs in premature infants and results in intermittent hypoxia (IH) to brain and other organs. While short episodes of apnea are considered of no clinical significance, prolonged apnea with bradycardia and large oxygen desaturation is associated with adverse neurological and cognitive outcome. The mechanisms of cognitive deficits in IH are poorly understood. We hypothesized that brief but multiple episodes of severe oxygen desaturation accompanied by bradycardia may affect early and late synaptic plasticity and produce long‐term cognitive deficits.C57BL/6 mouse pups were exposed to IH paradigm consisting of alternating cycles of 5% oxygen for 2.5 min and room air for 5–10 min, 2 h a day from P3 to P7. Long term potentiation (LTP) of synaptic strength in response to high frequency stimulation in hippocampal slices were examined 3 days and 6 weeks after IH. LTP was decreased in IH group relative to controls at both time points. That decrease was associated with deficits in spatial memory on Morris water maze and context fear conditioning test. Hypomyelination was observed in multiple gray and white matter areas on in vivo MRI using micromolecule proton fraction and ex vivo diffusion tensor imaging. No difference in caspase labeling was found between control and IH groups.We conclude that early changes in synaptic plasticity occurring during severe episodes of neonatal IH and persisting to adulthood may represent functional and structural substrate for long term cognitive deficits.
Opportunity discovery in initiated and emergent change requests
Authors: Sjögren Peter , Fagerström Björn , Kurdve Martin , Lechler Thomas 
Published: March 2019

When a change request is raised in an engineering project anad hocteam often forms to manage the request. Prior research shows that practitioners often view engineering changes in a risk-averse manner. As a project progresses the cost of changes increases. Therefore, avoiding changes is reasonable. However, a risk-averse perspective fails to recognize that changes might harbor discoverable and exploitable opportunities. In this research, we investigated how practitioners ofad hocteams used practices and praxes aimed at discovering and exploiting opportunities in engineering change requests. A single case study design was employed using change request records and practitioner interviews from an engineering project. 87 engineering change requests were analyzed with regards to change triggers, time-to-decision and rejection rate. In total, 25 opportunities were discovered and then 17 exploited. Three practices and six praxes were identified, used by practitioners to discover and exploit opportunities. Our findings emphasize the importance of the informal structure ofad hocteams, to aid in opportunity discovery. The informal structure enables cross-hierarchal discussions and draws on the proven experience of the team members. Thus, this research guides project managers and presumptivead hocteams in turning engineering changes into successful opportunities.
Using life history calendars to improve measurement of lifetime experience with mental disorders
Authors: Axinn William G. , Chardoul Stephanie , Gatny Heather , Ghimire Dirgha J. , Smoller Jordan W. , Zhang Yang , Scott Kate M. 
Published: March 2019

AbstractBackgroundRetrospective reports of lifetime experience with mental disorders greatly underestimate the actual experiences of disorder because recall error biases reporting of earlier life symptoms downward. This fundamental obstacle to accurate reporting has many adverse consequences for the study and treatment of mental disorders. Better tools for accurate retrospective reporting of mental disorder symptoms have the potential for broad scientific benefits.MethodsWe designed a life history calendar (LHC) to support this task, and randomized more than 1000 individuals to each arm of a retrospective diagnostic interview with and without the LHC. We also conducted a careful validation with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition.ResultsResults demonstrate that—just as with frequent measurement longitudinal studies—use of an LHC in retrospective measurement can more than double reports of lifetime experience of some mental disorders.ConclusionsThe LHC significantly improves retrospective reporting of mental disorders. This tool is practical for application in both large cross-sectional surveys of the general population and clinical intake of new patients.
Sexual violence and mental health services: a call to action
Authors: Hughes Elizabeth , Lucock Michael , Brooker Charlie 
Published: March 2019

AbstractPeople who experience sexual violence are highly likely to experience psychological and/or mental health (MH) problems as a result. People who use MH services often have a history of sexual assault and are also likely to be revictimised as an adult. Yet despite there being a very clear association, MH services are not yet performing routine enquiry, and even if they do, are not confident about how to record and manage disclosures. There is some emerging evidence that people with MH problems are exposed to sexual violence in inpatient MH settings, perpetrated by both other patients or members of staff. In this editorial, we explore the evidence to support a wider focus on sexual violence as a part of routine care, as well as some recommendations about how staff can more effectively discuss sexual issues including that of sexual victimisation.
Vitamin B12 and folic acid associated megaloblastic anemia: Could it mislead the diagnosis of breast cancer?
Authors: Karakoyun Inanc , Duman Can , Demet Arslan Fatma , Baysoy Anil , Isbilen Basok Banu 
Published: March 2019

Abstract. CA 15-3 is a tumor-associated antigen and is overexpressed in breast tumors, and may also be high in some other non-cancerous conditions. The aim of this study was to investigate the effect of megaloblastic anemia due to vitamin B12 or folic acid deficiency on the levels of tumor markers. Five-year patient data were retrospectively analyzed. The associations between megaloblastic anemia due to vitamin B12 deficiency and CA 15-3, CA 125, CA 19-9, CEA, and AFP levels were analyzed. Furthermore, association between CA 15-3 level and megaloblastic anemia due to folic acid deficiency was evaluated. Median CA 15-3 level was 38.1 U/mL in the group with megaloblastic anemia due to vitamin B12 deficiency(n = 15), 46.7 U/mL in the group with megaloblastic anemia related to folic acid deficiency (n = 3), and 17.8 U/mL in the normal group(n = 1724). CA 15-3 levels were significantly higher among patients with vitamin B12- and folic acid-associated megaloblastic anemia compared to the normal group (p = 0.001 and p = 0.005, respectively). Megaloblastic anemia due to vitamin B12 deficiency was not associated with any significant differences in CA 125, CA 19-9, CEA, or AFP levels compared to the normal group (p = 0.777, p = 0.327, p = 0.577, and p = 0.197, respectively). The numbers of anemic and normal subjects compared in these tests were 12 vs. 1501, 17 vs. 1827, 4 vs. 897, and 8 vs. 1041, respectively. In conclusion, megaloblastic anemia results in ineffective erythropoiesis, and increased levels of CA 15-3 may be associated with this issue. Clinicians should take this into account when evaluating for a pre-diagnosis of breast cancer.
Energetic Electron Precipitation: Multievent Analysis of Its Spatial Extent During EMIC Wave Activity
Authors: Capannolo L. , Li W. , Ma Q. , Shen X.‐C. , Zhang X.‐J. , Redmon R. J. , Rodriguez J. V. , Engebretson M. J. , Kletzing C. A. , Kurth W. S. , Hospodarsky G. B. , Spence H. E. , Reeves G. D. , Raita T. 
Published: March 2019

AbstractElectromagnetic ion cyclotron (EMIC) waves can drive precipitation of tens of keV protons and relativistic electrons, and are a potential candidate for causing radiation belt flux dropouts. In this study, we quantitatively analyze three cases of EMIC‐driven precipitation, which occurred near the dusk sector observed by multiple Low‐Earth‐Orbiting (LEO) Polar Operational Environmental Satellites/Meteorological Operational satellite programme (POES/MetOp) satellites. During EMIC wave activity, the proton precipitation occurred from few tens of keV up to hundreds of keV, while the electron precipitation was mainly at relativistic energies. We compare observations of electron precipitation with calculations using quasi‐linear theory. For all cases, we consider the effects of other magnetospheric waves observed simultaneously with EMIC waves, namely, plasmaspheric hiss and magnetosonic waves, and find that the electron precipitation at MeV energies was predominantly caused by EMIC‐driven pitch angle scattering. Interestingly, each precipitation event observed by a LEO satellite extended over a limited L shell region (ΔL ~ 0.3 on average), suggesting that the pitch angle scattering caused by EMIC waves occurs only when favorable conditions are met, likely in a localized region. Furthermore, we take advantage of the LEO constellation to explore the occurrence of precipitation at different L shells and magnetic local time sectors, simultaneously with EMIC wave observations near the equator (detected by Van Allen Probes) or at the ground (measured by magnetometers). Our analysis shows that although EMIC waves drove precipitation only in a narrow ΔL, electron precipitation was triggered at various locations as identified by POES/MetOp over a rather broad region (up to ~4.4 hr MLT and ~1.4 L shells) with similar patterns between satellites.
A Technique to Infer Magnetic Topology at Mars and Its Application to the Terminator Region
Authors: Xu Shaosui , Weber Tristan , Mitchell David L. , Brain David A. , Mazelle Christian , DiBraccio Gina A. , Espley Jared 
Published: March 2019

AbstractMagnetic topology is important for understanding the Martian plasma environment, including particle precipitation, energy transport, cold ion escape, and wave‐particle interaction. In this study, we combine two independent but complementary methods in order to determine magnetic topology based on superthermal electron energy and pitch angle distributions. This approach removes ambiguities that result from using either energy or pitch angle alone, providing a more accurate and comprehensive determination of magnetic topology than previous studies. By applying this combined technique, we are able to identify seven magnetic topologies, including four types of closed field lines, two types of open field lines, and draped. All seven topologies are present in the Mars environment and are mapped in longitude, latitude, solar zenith angle, and altitude with the combined technique near the terminator. We find that closed field lines with double‐sided loss cones are frequently present over stronger crustal field regions at higher altitudes. We also show that the cross‐terminator closed field lines are more spatially confined over strong crustal regions, likely connecting nearby magnetic crustal patches. In contrast, cross‐terminator closed loops over weak crustal regions have more distantly separated foot points, most likely connecting distant crustal patches.
Statistical Analysis of Hiss Waves in Plasmaspheric Plumes Using Van Allen Probe Observations
Authors: Kim Kyung‐Chan , Shprits Yuri 
Published: March 2019

AbstractPlasmaspheric hiss waves commonly observed in high‐density regions in the Earth's magnetosphere are known to be one of the main contributors to the loss of radiation belt electrons. There has been a lot of effort to investigate the distributions of hiss waves in the plasmasphere, while relatively little attention has been given to those in the plasmaspheric plume. In this study, we present for the first time a statistical analysis of the occurrence and the spatial distribution of wave amplitudes and wave normal angles for hiss waves in plumes using Van Allen Probes observations during the period of October 2012 to December 2016. Statistical results show that a wide range of hiss wave amplitudes in plumes from a few picotesla to >100 pT is observed, but a modest (<20 pT) wave amplitude is more commonly observed regardless of geomagnetic activity in both the midnight‐to‐dawn and dusk sector. By contrast, stronger amplitude hiss occurs preferentially during geomagnetically active times in the dusk sector. The wave normal angles are distributed over a broad range from 0° to 90° with a bimodal distribution: a quasi‐field‐aligned population (<20°) with an occurrence rate of <60% and an oblique one (>50°) with a relative low occurrence rate of ≲20%. Therefore, from a statistical point of view, we confirm that the hiss intensity (a few tens of picotesla) and field‐aligned hiss wave adopted in previous simulation studies are a reasonable assumption but stress that the activity dependence of the wave amplitude should be considered.
Sensitivity of Seismic Velocity Changes to the Tidal Strain at Different Lapse Times: Data Analyses of a Small Seismic Array at Izu‐Oshima Volcano
Authors: Takano Tomoya , Nishimura Takeshi , Nakahara Hisashi , Ueda Hideki , Fujita Eisuke 
Published: March 2019

AbstractWe investigate seismic velocity changes in response to the tidal strain at Izu‐Oshima volcano, Japan, by analyzing the data of permanent seismic stations and a small seismic array to evaluate the characteristics of strain sensitivity of velocity changes. We estimate the seismic velocity changes by phase differences between cross‐correlations functions of ambient noises at the frequency of 2–4 Hz stacked for time periods with different tidal strain amplitudes. The seismic velocity changes decrease and increase during dilatation and contraction periods, respectively, when analyzing the cross‐correlations functions at early lapse times ranging from 2 to 7 s. The strain sensitivity of seismic velocity changes is estimated to beat the early lapse times. However, we find that strain sensitivity of the seismic velocity changes decreases when analyzing the cross‐correlation functions at later lapse times from 7 s to 35 s. Applying an array analysis to the cross‐correlation functions, we observe apparent velocities of about 1 km/s at the early lapse times and those of higher than 1 km/s at the late lapse times. Since the group velocity of Rayleigh waves is 1.1 km/s at Izu‐Oshima volcano, the apparent velocities at the late lapse times may indicate the scattered or reflected body waves incident from a deeper region. Decrease of strain sensitivity with the lapse times therefore results from the emergence of body waves on the late lapse times. These results highlight the need to pay attention to wave types of cross‐correlation functions and their paths to interpret seismic velocity changes.