bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and dynamical description of the enzymatic reaction of a phosphohexomutase
Authors: Stiers Kyle M. , Graham Abigail C. , Zhu Jian-She , Jakeman David L. , Nix Jay C. , Beamer Lesa J.
Published: April 2019

Enzymes are known to adopt various conformations at different points along their catalytic cycles. Here, we present a comprehensive analysis of 15 isomorphous, high resolution crystal structures of the enzyme phosphoglucomutase from the bacterium Xanthomonas citri. The protein was captured in distinct states critical to function, including enzyme-substrate, enzyme-product, and enzyme-intermediate complexes. Key residues in ligand recognition and regions undergoing conformational change are identified and correlated with the various steps of the catalytic reaction. In addition, we use principal component analysis to examine various subsets of these structures with two goals: (1) identifying sites of conformational heterogeneity through a comparison of room temperature and cryogenic structures of the apo-enzyme and (2) a priori clustering of the enzyme-ligand complexes into functionally related groups, showing sensitivity of this method to structural features difficult to detect by traditional methods. This study captures, in a single system, the structural basis of diverse substrate recognition, the subtle impact of covalent modification, and the role of ligand-induced conformational change in this representative enzyme of the α-D-phosphohexomutase superfamily.
Helium users are at the mercy of suppliers
Authors: Kramer David
Published: April 2019

Researchers seek government help in addressing supply shortage as prices are expected to continue soaring.
The invisible dance of CRISPR-Cas9
Authors: Palermo Giulia , Ricci Clarisse G. , McCammon J. Andrew
Published: April 2019

Simulations unveil the molecular side of the gene-editing revolution.
Modeling cocaine traffickers and counterdrug interdiction forces as a complex adaptive system
Authors: Magliocca Nicholas R. , McSweeney Kendra , Sesnie Steven E. , Tellman Elizabeth , Devine Jennifer A. , Nielsen Erik A. , Pearson Zoe , Wrathall David J.
Published: April 2019

Counterdrug interdiction efforts designed to seize or disrupt cocaine shipments between South American source zones and US markets remain a core US “supply side” drug policy and national security strategy. However, despite a long history of US-led interdiction efforts in the Western Hemisphere, cocaine movements to the United States through Central America, or “narco-trafficking,” continue to rise. Here, we developed a spatially explicit agent-based model (ABM), called “NarcoLogic,” of narco-trafficker operational decision making in response to interdiction forces to investigate the root causes of interdiction ineffectiveness across space and time. The central premise tested was that spatial proliferation and resiliency of narco-trafficking are not a consequence of ineffective interdiction, but rather part and natural consequence of interdiction itself. Model development relied on multiple theoretical perspectives, empirical studies, media reports, and the authors’ own years of field research in the region. Parameterization and validation used the best available, authoritative data source for illicit cocaine flows. Despite inherently biased, unreliable, and/or incomplete data of a clandestine phenomenon, the model compellingly reproduced the “cat-and-mouse” dynamic between narco-traffickers and interdiction forces others have qualitatively described. The model produced qualitatively accurate and quantitatively realistic spatial and temporal patterns of cocaine trafficking in response to interdiction events. The NarcoLogic model offers a much-needed, evidence-based tool for the robust assessment of different drug policy scenarios, and their likely impact on trafficker behavior and the many collateral damages associated with the militarized war on drugs.
Boron–oxygen complex yields n-type surface layer in semiconducting diamond
Authors: Liu Xiaobing , Chen Xin , Singh David J. , Stern Richard A. , Wu Jinsong , Petitgirard Sylvain , Bina Craig R. , Jacobsen Steven D.
Published: April 2019

Significance

Diamond is a uniquely attractive wide-bandgap semiconductor for future electronic devices where its remarkable physical properties may enable switches, transistors, and diodes for extreme applications. Whereas p-type semiconducting diamond is well developed with boron doping, the synthesis of n-type diamond, required to complete purely diamond-based electronics, has been a great challenge in materials science. We report the creation of n-type diamond via a new type of defect complexes of boron and oxygen that can be tuned by controlling the experimental parameters for diamond crystallization, leading to a shallow donor state with high carrier concentration that is several orders of magnitude higher than achieved by sulfur or phosphorus doping. The results provide a new strategy for producing n-type diamond-based devices.
Night-sky radiometry can revolutionize the characterization of light-pollution sources globally
Authors: Kocifaj Miroslav , Solano-Lamphar Héctor Antonio , Videen Gorden
Published: April 2019

Significance

Anthropogenic skyglow is currently a serious threat to natural environments near human settlements; however, a spread of light over wide areas is difficult to predict due to uncertainties in the city emission function (CEF) from many light sources. The CEF determines the rate at which skyglow varies with distance to a light source but remains virtually unexplored because appropriate retrieval tools have been unavailable. However, we have now obtained the CEF from ground-based night-sky radiometry and conducted a successful experiment to retrieve the CEF of an urban area. The method provides information on the CEF and allows for its systematic full-area economic monitoring while initiating a phase in light-pollution research.
The STEP
61
interactome reveals subunit-specific AMPA receptor binding and synaptic regulation
Authors: Won Sehoon , Incontro Salvatore , Li Yan , Nicoll Roger A. , Roche Katherine W.
Published: April 2019

Significance

Striatal-enriched protein tyrosine phosphatase (STEP) regulates the trafficking and function of a variety of synaptic proteins, including receptors and protein kinases. In addition, STEP’s expression and activity are altered in many neuropsychiatric disorders. Here, we isolate the STEP
61
interactome, which includes known interactors such as NMDA receptor (NMDAR) subunits, PSD-95, and Fyn kinase. In addition, we identified the AMPA receptor (AMPAR) GluA2 subunit as a binding protein. We show that STEP
61
binds to the C termini of GluA2 and GluA3, but not GluA1. Furthermore, we show that STEP
61
dephosphorylates GluA2, thereby regulating synaptic GluA2-containing AMPARs via endocytosis and lysosomal degradation. STEP
61
preferentially regulates synaptic AMPARs and extrasynaptic NMDARs, revealing a role for STEP
61
in defining activity-dependent glutamate receptor localization.
Prion protein quantification in human cerebrospinal fluid as a tool for prion disease drug development
Authors: Vallabh Sonia M. , Nobuhara Chloe K. , Llorens Franc , Zerr Inga , Parchi Piero , Capellari Sabina , Kuhn Eric , Klickstein Jacob , Safar Jiri G. , Nery Flavia C. , Swoboda Kathryn J. , Geschwind Michael D. , Zetterberg Henrik , Arnold Steven E. , Minikel Eric Vallabh , Schreiber Stuart L.
Published: April 2019

Significance

Human prion disease is a rapidly fatal and incurable neurodegenerative disease. Reduction of prion protein in the brain is a well-supported therapeutic hypothesis, and antisense oligonucleotides with this mechanism of action are currently in development. To facilitate clinical testing of prion protein-lowering drugs in prion disease, we show that with proper sample handling, brain prion protein levels can be monitored in cerebrospinal fluid, using existing tools, and exhibit suitable short-term stability for drug-dependent decreases to be reliably measured. Cerebrospinal fluid prion protein levels thus may usefully serve as a pharmacodynamic biomarker. This biomarker may open new paths for informative clinical trials in presymptomatic individuals who harbor high-risk mutations for genetic prion disease.
Interaction of epitaxial graphene with heavy metals: towards novel sensing platform
Authors: Shtepliuk Ivan , Yakimova Rositsa
Published: April 2019

Development of next-generation sensors based on graphene materials, especially epitaxial graphene (EG) as the most promising representative, with desirable cross-reactivity to heavy metals (HMs) is of great technological significance in the virtue of enormous impact on environmental sensorics. Nevertheless, the mechanisms by which EG responds to toxic HMs exposure and then produces the output signal are still obscure. In the present study, the nature of interaction of toxic HMs, e.g. Cd, Hg and Pb in neutral charge state and EG on Si-face SiC in the absence and in the presence of pure water solution has been investigated using density functional theory with the inclusion of dispersion correction and cluster model of EG. The gas-phase calculations showed that adsorbed electron-donating Cd and Hg adatoms on EG are most stable when bonded to hollow sites, while Pb species prefer to sit above bridge sites. By using non-covalent interaction analysis, charge decomposition analysis, overlap population density of states analysis and topological analysis, it was found that the interaction between Cd or Hg and EG is non-bonding in nature and is mainly governed by van der Waals forces, while Pb adsorption is followed by the formation of anti-bonding orbitals in vacuum conditions and bonding orbitals in water. The role of solvent in the adsorption behavior of HMs is studied and discussed. The present theoretical analysis is in good agreement with recent experimental results towards discriminative electrochemical analysis of the toxic HMs in aqueous solutions at critically low concentrations.
Imprecise Quantification
Authors: Roberts Alexander
Published: April 2019

Following David Lewis (1986), Ted Sider (2001) has famously argued that unrestricted first-order quantification cannot be vague. His argument was intended as a type of reductio: its strategy was to show that the mere hypothesis of unrestricted quantifier vagueness collapses into the claim that unrestricted quantification is precise. However, this short article considers two natural reconstructions of the argument, and shows that each can be resisted. The theme will be that each reconstruction of the argument involves assumptions which advocates of vague quantification have independent reason to reject.
Comparison and integration of computational methods for deleterious synonymous mutation prediction
Authors: Cheng Na , Li Menglu , Zhao Le , Zhang Bo , Yang Yuhua , Zheng Chun-Hou , Xia Junfeng
Published: April 2019

Synonymous mutations do not change the encoded amino acids but may alter the structure or function of an mRNA in ways that impact gene function. Advances in next generation sequencing technologies have detected numerous synonymous mutations in the human genome. Several computational models have been proposed to predict deleterious synonymous mutations, which have greatly facilitated the development of this important field. Consequently, there is an urgent need to assess the state-of-the-art computational methods for deleterious synonymous mutation prediction to further advance the existing methodologies and to improve performance. In this regard, we systematically compared a total of 10 computational methods (including specific method for deleterious synonymous mutation and general method for single nucleotide mutation) in terms of the algorithms used, calculated features, performance evaluation and software usability. In addition, we constructed two carefully curated independent test datasets and accordingly assessed the robustness and scalability of these different computational methods for the identification of deleterious synonymous mutations. In an effort to improve predictive performance, we established an ensemble model, named Prediction of Deleterious Synonymous Mutation (PrDSM), which averages the ratings generated by the three most accurate predictors. Our benchmark tests demonstrated that the ensemble model PrDSM outperformed the reviewed tools for the prediction of deleterious synonymous mutations. Using the ensemble model, we developed an accessible online predictor, PrDSM, available at http://bioinfo.ahu.edu.cn:8080/PrDSM/. We hope that this comprehensive survey and the proposed strategy for building more accurate models can serve as a useful guide for inspiring future developments of computational methods for deleterious synonymous mutation prediction.
A mayfly’s rapid transition toward unisexual populations
Authors: Sekiné K , Tojo K
Published: April 2019

Sexual reproduction is overwhelmingly the most common reproductive mode among Metazoans, although it has been secondarily lost in some organisms. Ephoron shigae is a geographically parthenogenetic mayfly. Here, we provide details of the frequency of bisexual and parthenogenetic strains of E. shigae together with data on their sex ratios in the Abukuma-gawa River and one of its downstream tributaries, the Surikami-gawa River, in Japan. In a previous study in the 1990s, bisexual populations were observed in both rivers. The present study clearly shows that sex ratios have since changed to be almost entirely unisexual within the downstream area of the Abukuma-gawa River and the Surikami-gawa River. Our genetic analyses also show that these females are of a parthenogenetic strain, and that the original bisexual strains were overwhelmed within a period of <20 years. However, it was recently observed that many males and females of the bisexual strains continue to inhabit upstream areas of the Abukuma-gawa River. Therefore, we suggest that the parthenogenetic strains have increased in abundance primarily downstream. We show that a drastic change has occurred over a short period, involving the replacement of one strain and a corresponding change in reproductive mode along a riverine environment.
Taxonomy-based differences in feeding guilds of fish
Authors: Sánchez-Hernández Javier
Published: April 2019

It has been taken for granted that feeding guilds and behavior in animals are linked to the taxonomic relatedness of species, but empirical evidence supporting such relationship is virtually missing. To examine the importance of taxonomy on trophic ecology, I here present the first well-resolved dietary taxonomy analysis based on feeding guilds (predation, herbivory, and filtering) among families and genera within the fish order Perciformes. Taxonomic relatedness in feeding did not vary with ecosystem dimension (marine vs. freshwater). Although predation dominates among Perciformes fishes, this study shows that in most cases taxonomic units (family or genus) are composed by species with several feeding guilds. Related species are more similar in feeding compared with species that are taxonomically more distant, demonstrating that there is a greater variation of feeding guilds within families than genera. Thus, there is no consistency in feeding guilds between family- and genus-level taxonomy. This study provides empirical support for the notion that genera are more informative than families, underlining that family-level taxonomy should be avoided to infer feeding habits of fish species at finer taxonomic resolution. Thus, the choice of taxonomic resolution (family or genus level) in ecological studies is key to avoid information loss and misleading results. I conclude that high-rank taxonomic units (i.e., above the generic level) are not appropriate to test research hypotheses about the feeding of fish.
RNA accumulation inCandida tropicalisbased on cofactor engineering
Authors: Li Bingbing , Liu Ying , Wang Lianzhe , Hong Jun , Chen Yong , Ying Hanjie
Published: April 2019

Redox cofactors play an important role in biosynthetic and catabolic reactions and the transfer of energy for the cell. Therefore, studying the relationship between cofactor perturbation and metabolism is a useful approach to improve the yield of target products. To study RNA accumulation and metabolism when intracellular cofactor balance was impaired, the water-forming NADH oxidase (NoxE) from Lactococcus lactis and membrane-bound transhydrogenase (PntAB) from Escherichia coli were expressed in Candidatropicalis no. 121, respectively. Expression of noxE significantly decreased the intracellular NADH/NAD+ ratio, but the NADPH/NADP+ ratio did not differ significantly. PntAB increased the intracellular NADH pool, while the NADPH/NADP+ ratio decreased. The perturbation of the cofactors caused a large redistribution of metabolic fluxes. The biomass and RNA content decreased by 11.0% and 10.6% in pAUR-noxE strain, respectively, while the RNA content increased by 5.5% and the biomass showed no signification difference in pAUR-pntAB strain. Expression of noxE and pntAB led to decreases and increases in the ATP concentration and yield of RNA, respectively, which also indicated that ATP plays an important role in the RNA biosynthesis.
Effect of temporal and spatial resolution on identification of fishing activities in small-scale fisheries using pots and traps
Authors: Mendo Tania , Smout Sophie , Russo Tommaso , D’Andrea Lorenzo , James Mark
Published: April 2019

Analysis of data from vessel monitoring systems and automated identification systems in large-scale fisheries is used to describe the spatial distribution of effort, impact on habitats, and location of fishing grounds. To identify when and where fishing activities occur, analysis needs to take account of different fishing practices in different fleets. Small-scale fisheries (SSFs) vessels have generally been exempted from positional reporting requirements, but recent developments of compact low-cost systems offer the potential to monitor them effectively. To characterize the spatial distribution of fishing activities in SSFs, positions should be collected with sufficient frequency to allow detection of different fishing behaviours, while minimizing demands for data transmission, storage, and analysis. This study sought to suggest optimal rates of data collection to characterize fishing activities at appropriate spatial resolution. In a SSF case study, on-board observers collected Global Navigation Satellite System (GNSS) position and fishing activity every second during each trip. In analysis, data were re-sampled to lower temporal resolutions to evaluate the effect on the identification of number of hauls and area fished. The effect of estimation at different spatial resolutions was also explored. Consistent results were found for polling intervals <60 s in small vessels and <120 in medium and large vessels. Grid cell size of 100 × 100 m resulted in best estimations of area fished. Remote collection and analysis of GNSS or equivalent data at low cost and sufficient resolution to infer small-scale fisheries activities. This has significant implications globally for sustainable management of these fisheries, many of which are currently unregulated.
Working with Others: Reflections on Fieldwork in Postconflict Societies
Authors: Lawther Cheryl , Killean Rachel , Dempster Lauren
Published: April 2019

In this Note from the Field we reflect on the challenges of doing sensitive fieldwork in postconflict and transitional societies. Our reflections are informed by sustained fieldwork with victims and perpetrators of violent conflict in a range of transitional jurisdictions. While undertaking this work, we have been acutely aware of the challenges raised by our own position in the field and by the power dynamics at play when working with partner organizations and speaking with vulnerable communities. Focusing on the themes of preparation, partners and positionality, this Note highlights the benefits and potential pitfalls of this style of qualitative work and seeks to encourage a more reflexive approach to working with victims and survivors of gross human rights violations.
A 5-Year Review of Pavement Burns From a Desert Burn Center
Authors: Vega Jorge , Chestovich Paul , Saquib Syed , Fraser Douglas
Published: April 2019

Pavement burns account for significant burn-related injuries in the Southwestern United States and other hot climates with nearly continuous sunlight and daily maximum temperatures above 100°F. At peak temperatures, pavement can be hot enough to cause second-degree burns in a matter of seconds. The goal of this study was to review pavement burn injury admissions at a desert burn center compared with maximum ambient temperatures to determine which temperatures correlated to an increase in burn admissions. We obtained ambient temperature data from the National Oceanic and Atmospheric Administration. We reviewed our registry for 5 years retrospectively of all pavement burn injury admissions to our burn center. A total of 173 pavement-related burn cases were identified. We demonstrated an exponential increase in the rate of burn admissions as maximum ambient temperatures increased. More than 88% of pavement-related burn injury admissions occurred when the ambient temperature reached 95°F or higher. The risk per day was extrapolated based on the number of pavement burn injury admissions and the number of days at each of the maximum ambient temperatures recorded. The risk of pavement burns in areas of direct sunlight begins around 95°F and increases exponentially as ambient temperatures rise. This information will be used for burn outreach prevention and public health awareness programs. The benefit of this study relates to the entire community since high ambient temperatures put everyone at risk for hot pavement burns.
Elevated nitrogen deposition may advance invasive weed, Solidago canadensis, in calcareous soils
Authors: Wan Ling-Yun , Qi Shan-Shan , Zou Chris B , Dai Zhi-Cong , Ren Guang-Qian , Chen Qi , Zhu Bin , Du Dao-Lin
Published: April 2019

Aims

Change in nitrogen (N) availability regulates phosphorus (P) acquisition and potentially alters the competition among native species and invasive weeds. This study determines how current and projected N deposition affect the growth, the intraspecific and interspecific competitive ability of native and invasive plants in calcareous soils with low P availability.

Methods

A controlled greenhouse experiment was conducted using sparingly soluble hydroxyapatite (HAP) to simulate the calcareous soils with low P availability. The growth and competitive intensity between an invasive weed (Solidago canadensis) and a native weed (Pterocypsela laciniata) exposed to two levels of N addition representative of current and future N deposition in China were experimentally determined.

Important Findings

P acquisition and the growth of both S. canadensis and P. laciniata growing alone significantly increased with increasing N level. However, the effect of N addition was reduced when intraspecific or interspecific competition existed. N addition altered the competitive relationship between S. canadensis and P. laciniata allowing S. canadensis to out-compete P. laciniata due to variation in P acquisition from HAP. Elevated N deposition might assist the invasion of S. canadensis in the widely distributed calcareous soils under environmental changes.
Association Between Dietary Supplement Use and ICD-9-CM Code Classification in Active Duty US Navy and Marine Corps Service Members
Authors: Humphreys Matthew A , Phillips Christopher J , Trone Daniel W
Published: April 2019

Introduction

This study is the first to our knowledge to examine associations of survey-reported dietary supplement use with medical record diagnoses, rather than retrospective self-reported supplement use at the time of the medical encounter or case reports of adverse events. Dietary supplement (DS) use and adverse events associations in US Navy and Marine Corps personnel remains unknown. This study assessed associations of DS use in active duty (AD) personnel with ICD-9-CM diagnostic codes from outpatient medical encounters from the Military Health System Data Repository (MDR).

Materials and Methods

This cross-sectional investigation used a one-time survey of DS use among AD conducted August through December 2014. Survey data were matched to MDR data accessed in September 2016, and associations between the survey responses and diagnoses were analyzed. Statistical significance was set at alpha level 0.005, and 99.5% confidence intervals (CIs) were calculated. MDR data were matched with survey results for 1,708 personnel. Multivariable logistic regression analyses examined whether use of specific classes of supplements was associated with disease.

Results

Results revealed significant associations between vitamin supplement use and ICD-9-CM-diagnosed diseases of the nervous system (odds ratio [OR]: 1.72, 99.5% CI: 1.11–2.68) and diseases of the musculoskeletal system and connective tissue (OR: 1.59, 99.5% CI: 1.17–2.17). Joint health supplement category use was associated with diseases of the musculoskeletal system and connective tissue (OR: 1.81, 99.5% CI: 1.12–2.94) and injury and poisoning (OR: 1.82, 99.5% CI: 1.10–3.04).

Conclusions

The percentages of service members with diseases in specific ICD-9-CM diagnostic categories were similar to those reported in other studies using military medical data. There is a greater prevalence of dietary supplement use by the service members who participated in this survey compared with the general population, with 73% of US Navy and Marine Corps personnel reporting use of dietary supplements one or more times per week compared to the estimated 50% of all Americans currently using some form of dietary supplement. The DoD ensures the optimal readiness, performance, and health of its military service members, thus future longitudinal evaluation of dietary supplement use by this population will test the preliminary findings of this study.
O v] λλ1213.8,1218.3 emission from extended nebulae around quasars: contamination of Ly α and a new diagnostic for AGN activity in Ly α emitters
Authors: Humphrey A
Published: April 2019

We investigate the potential for the emission lines O v] λλ1213.8,1218.3 and He ii λ1215.1 to contaminate flux measurements of Ly α λ1215.7 in the extended nebulae of quasars. We have computed a grid of photoionization models with a substantial range in the slope of the ionizing power law (−1.5 < α < −0.5), gas metallicity (0.01 < Z/Z⊙ < 3.0), gas density (1 < nH < 104 cm−3), and ionization parameter (10−5 < U < 1.0). We find the contribution from He ii λ1215.1 to be negligible, i.e. <0.1 of Ly α flux, across our entire model grid. The contribution from O v] λλ1213.8,1218.3 is generally negligible when U is low (≲10−3) and/or when the gas metallicity is low (Z/Z⊙ ≲ 0.1). However, at higher values of U and Z we find that O v] can significantly contaminate Ly α, in some circumstances accounting for more than half the total flux of the Ly α + He ii + O v] blend. We also provide means to estimate the fluxes of O v] λλ1213.8,1218.3 and He ii λ1215.1 by extrapolating from other lines. We estimate the fluxes of O v] and He ii for a sample of 107 Type 2 active galaxies at z > 2, and find evidence for significant (≥10 per cent) contamination of Ly α fluxes in the majority of cases (84 per cent). We also discuss prospects for using O v] λλ1213.8,1218.3 as a diagnostic for the presence of AGN activity in high-z Ly α emitters, and caution that the presence of significant O v] emission could impact the apparent kinematics of Ly α, potentially mimicking the presence of high-velocity gas outflows.
An Extension of the Minimally Divergent Contour Network: Considering Nonconsecutive Repeated Contour Pitches
Authors: Wu Yi-Cheng Daniel
Published: April 2019

In a 2013 article, I partitioned all musical contours into fifteen types and arranged them in a network called the minimally divergent contour network (MDCN). Within the MDCN, we can examine the similarity between any two contour types by measuring the shortest path between them. However, despite the methodological efficiency, none of the fifteen types considers nonconsecutive repeated contour pitches. Prompted by this issue, this article extends the MDCN to include nonconsecutive repeated contour pitches. To demonstrate the analytic utility of the extended MDCN, I examine works by Bright Sheng and György Kurtág.
Rock-salt and helix structures of silver iodides under ambient conditions
Authors: Huang Hongyang , Zhang Jinying , Zhang Yifan , Fu Chengcheng , Huang Jialiang , Cheng Yonghong , Niu Chunming , Zhao Xinluo , Shinohara Hisanori
Published: April 2019

Many different phase structures have been discovered for silver iodides. The β and γ phases were found to be the most common ones at ambient conditions, while the rock-salt phase was found to be stable under pressures between 400 MPa and 11.3 GPa. Recently, the α phase was demonstrated to be stable under ambient conditions when the particle sizes were reduced to below 10 nm. However, no other phase has been reported to be stable for silver iodides under ambient conditions. Rock-salt and helix structures have been found to be stable under ambient conditions in this study. The structures have been characterized by elemental mapping, Raman scattering, and high-resolution transmission electron microscopy. The stabilities of these structures were also confirmed by molecular dynamics and density functional theory.
Utrecht Pediatric Wheelchair Mobility Skills Test: Reliability, Validity, and Responsiveness in Youths Using a Manual Wheelchair
Authors: Sol Marleen E , de Groot Janke F , Zwinkels Maremka , Visser-Meily J M Anne , Kruitwagen Cas L J J , Verschuren Olaf
Published: April 2019

Background

The assessment of wheelchair mobility skills (WMS) in youths using a manual wheelchair is important. More information is needed regarding the psychometric properties of the newly developed Utrecht Pediatric Wheelchair Mobility Skills Test (UP-WMST).

Objective

The purpose of this study was to evaluate the reliability, content validity, construct validity, and responsiveness of the UP-WMST 2.0 in youths using a manual wheelchair.

Design

This was a repeated-measurements, cross-sectional study.

Methods

A total of 117 children and adolescents who use a manual wheelchair participated in this study. The UP-WMST 2.0 contains the same 15 WMS items as the original UP-WMST but has an adaptation of the scoring method. Test-retest reliability was estimated in 30 participants. Content validity was assessed through floor and ceiling effect analyses. Construct validity was assessed through hypothesis testing. Preliminary estimates of responsiveness were assessed in 23 participants who participated in a WMS training program.

Results

Test-retest reliability analysis showed weighted Cohen kappa coefficients ranging from 0.63 to 0.98 for all but 1 item. The total UP-WMST 2.0 score had an intraclass correlation coefficient of 0.97. No floor or ceiling effects were detected. Independent-sample t test analysis confirmed our hypotheses regarding direction and difference in scores between age and diagnostic groups. Within-group analysis in the responsiveness study showed a positive significant change in UP-WMST 2.0 score (8.3 points).

Limitations

The small sample size used in the responsiveness study was a limitation of this study.

Conclusions

This study provided evidence of the test-retest reliability, content, and construct validity of the UP-WMST 2.0. It also provided initial evidence of the responsiveness of the UP-WMST 2.0 for measuring change in WMS in youths using a manual wheelchair.
Autophagy mediates 2-methoxyestradiol-inhibited scleroderma collagen synthesis and endothelial-to-mesenchymal transition induced by hypoxia
Authors: Liu Chaofan , Zhou Xing , Lu Jinghao , Zhu Lubing , Li Ming
Published: April 2019

Objectives

To investigate whether autophagy mediates 2-methoxyestradiol (2-ME)-inhibited hypoxia-induced fibrosis and endothelial-to-mesenchymal transition (endoMT) in SSc.

Methods

Autophagy in the skin of SSc patients was assessed by transmission electron microscopy. SSc skin fibroblasts and human umbilical vein endothelial cells (HUVECs) were cultured under hypoxic (1% O2) conditions with 2-ME or autophagy inhibitor. Collagen I and connective tissue growth factor (CTGF) in fibroblasts and vascular endothelial (VE)-cadherin, CD31, vimentin and α-smooth muscle actin (α-SMA) in HUVECs were examined by western blotting. Autophagic markers were evaluated by confocal microscopy and immunofluorescence.

Results

SSc skins presented increased autolysosomes, LC3-II, collagen I and CTGF. Hypoxia-challenged fibroblasts and HUVECs formed more autophagosomes and autolysosomes, with increased LC3 and decreased P62. Meanwhile, hypoxia increased collagen I and CTGF in fibroblasts and increased vimentin and α-SMA but decreased VE-cadherin and CD31 in HUVECs. Bafilomycin A1 increased LC3-II and P62 in fibroblasts and HUVECs and decreased collagen I and CTGF in fibroblasts and vimentin and α-SMA in HUVECs, while upregulating VE-cadherin and CD31. 3-methyladenine decreased autophagy and fibrosis in fibroblasts and endothelial-to-mesenchymal transition in HUVECs. 2-ME-treated HUVECs showed more autophagosomes and fewer autolysosomes while 2-ME-treated fibroblasts showed fewer of both. Moreover, 2-ME decreased LC3-II and increased P62 in fibroblasts and increased both in HUVECs. Inhibition of autophagy by 2-ME showed the same effect with bafilomycin A1 on fibroblast collagen synthesis as well as endothelial and mesenchymal markers in HUVECs.

Conclusion

Autophagy mediated hypoxia-induced fibroblast collagen synthesis and endoMT in SSc, which could be reversed by 2-ME.
Radiation dose is of limited clinical usefulness in persons with acute radiation syndrome
Authors: Port Matthias , Majewski Matthäus , Abend Michael
Published: April 2019

The relation of radiation exposure (dose) with acute radiation syndrome (ARS) depends on many factors. In this overview, we reconsider (1) radiation exposure characteristics (e.g. radiation quality, fractionation, dose rate, partial/total body irradiation) and (2) biological processes (e.g. radiosensitivity, cell cycle dependency, oxygenation) affecting acute health effects after exposure. Furthermore we include evidence from recently published work that examined the relationship of absorbed dose and risk of clinically relevant ARS in persons exposed after a radiation accident. We introduce the concept of radiation-related bioindicators for effect prediction. Bioindicators are considered here to be factors that integrate multiple radiation exposure characteristics and cell- and molecular-based processes to improve clinical prediction in persons with ARS.
DEVELOPMENT OF A PELTIER TYPE CLOUD CHAMBER WITH WIDE VIEW FIELD
Authors: Toda Takehiro , Hasan Md Mahamudul , Igarashi Yu , Katengeza Estiner W , Iimoto Takeshi
Published: April 2019

Cloud chamber contributes to radiation education by facilitating observation of particle tracks formed by radiation. Peltier-based chamber achieves cooling without the need for dry ice,. we developed a cloud chamber based on peltier thermoelectric modules and has a multilayered heat insulation system to maintain a stable cool environment. It produces sharp particle tracks without requiring a dark room for observing the tracks. Its large top window (diameter of 12.5 cm) provides a relatively wider observation field capable of accommodating five to six students at a time.
Arabidopsis thaliana Seedlings Influence Bacillus subtilis Spore Formation
Authors: Charron-Lamoureux Vincent , Beauregard Pascale B.
Published: April 2019

Bacillus subtilis is a Gram-positive plant-growth-promoting rhizobacterium exerting many beneficial effects on plant health. Because they secrete antimicrobial compounds and elicit induced systemic resistance, B. subtilis and phylogenetically related species are of particular interest as antifungals in organic agriculture. These bacteria are also known for their capacity to differentiate phenotypically into endospores able to withstand many environmental stresses. However, although B. subtilis is often inoculated on plants as spores, dynamics of germination and sporulation on roots remain unexplored. Using a hydroponic culture system and a soil system for Arabidopsis thaliana, we observed that B. subtilis spores germinate rapidly on contact with plants. However, the vegetative cells are abundant on roots for only a few days before reversing back to spores. We observed that the germinant receptor GerK and sporulation kinases KinA and KinB identified in vitro control sporulation dynamics on plants. Surprisingly, when plants are inoculated with B. subtilis, free-living cells sporulate more rapidly than plant-associated cells. However, direct contact between plant and bacteria is required for the induction of sporulation in the surrounding B. subtilis. This study has fundamental implications for our understanding of interactions between Bacillus spp. and plants, and particularly for a more efficient usage of B. subtilis as a biofertilizer or biofungicide.
Plant Growth Promotion Driven by a Novel Caulobacter Strain
Authors: Luo Dexian , Langendries Sarah , Mendez Sonia Garcia , De Ryck Joren , Liu Derui , Beirinckx Stien , Willems Anne , Russinova Eugenia , Debode Jane , Goormachtig Sofie
Published: April 2019

Soil microbial communities hold great potential for sustainable and ecologically compatible agriculture. Although numerous plant-beneficial bacterial strains from a wide range of taxonomic groups have been reported, very little evidence is available on the plant-beneficial role of bacteria from the genus Caulobacter. Here, the mode of action of a Caulobacter strain, designated RHG1, which had originally been identified through a microbial screen for plant growth-promoting (PGP) bacteria in maize (Zea mays), is investigated in Arabidopsis thaliana. RHG1 colonized both roots and shoots of Arabidopsis, promoted lateral root formation in the root, and increased leaf number and leaf size in the shoot. The genome of RHG1 was sequenced and was utilized to look for PGP factors. Our data revealed that the bacterial production of nitric oxide, auxins, cytokinins, or 1-aminocyclopropane-1-carboxylate deaminase as PGP factors could be excluded. However, the analysis of brassinosteroid mutants suggests that an unknown PGP mechanism is involved that impinges directly or indirectly on the pathway of this growth hormone.
Analysis of Cytology and Expression of Resistance Genes in Maize Infected with Sporisorium reilianum
Authors: Qi Fengkun , Zhang Lin , Dong Xiaojie , Di Hong , Zhang Jiayue , Yao Minhao , Dong Ling , Zeng Xing , Liu Xianjun , Wang Zhenhua , Zhou Yu
Published: April 2019

Head smut, caused by the fungus Sporisorium reilianum, is a devastating global disease of maize (Zea mays). In the present study, maize seedlings were artificially inoculated with compatible mating-type strains of S. reilianum by needle inoculation of mesocotyls (NIM) or by soaking inoculation of radicles (SIR). After NIM or SIR, Huangzao4 mesocotyls exhibited severe damage with brownish discoloration and necrosis, whereas Mo17 mesocotyls exhibited few lesions. Fluorescence and electron microscopy showed that S. reilianum infected maize within 0.5 day after SIR and mainly colonized the phloem. With longer incubation, the density of S. reilianum hyphae increased in the vascular bundles, concentrated mainly in the phloem. In Mo17, infected cells exhibited apoptosis-like features, and hyphae became sequestered within dead cells. In contrast, in Huangzao4, pathogen invasion resulted in autophagy that failed to prevent hyphal spreading. The growth of S. reilianum hyphae diminished at 6 days after inoculation when expression of the R genes ZmWAK and ZmNL peaked. Thus, 6 days after SIR inoculation might be an important time for inhibiting the progress of S. reilianum infection in maize. The results of this study will provide a basis for further analysis of the mechanisms of maize resistance to S. reilianum.
Fungicide Sensitivity Monitoring of Alternaria spp. Causing Leaf Spot of Sugarbeet (Beta vulgaris) in the Upper Great Lakes
Authors: Rosenzweig N. , Hanson L. E. , Mambetova S. , Jiang Q. W. , Guza C. , Stewart J. , Somohano P.
Published: April 2019

Alternaria leaf spot (ALS), caused by Alternaria spp., can occur wherever sugarbeet is grown. Infection by Alternaria spp. and disease management has historically been considered a minor issue in sugarbeet production in the United States. An increase of both incidence and severity in 2016 of ALS high enough to cause yield loss has been observed in Michigan. With a renewed need to consider potential management of this disease, the sensitivity was determined for populations of Alternaria spp. to three classes of fungicides currently labeled for management of leaf spot on sugarbeet, including demethylase inhibitor (DMI), quinone outside inhibitor (QoI), and organo-tin fungicides. Leaves with symptoms of ALS were sampled from sugarbeet fields in east-central Michigan and southwestern Ontario, Canada. Monoconidial isolates were obtained to determine sensitivity to each fungicide class above. A spiral gradient dilution method was used to estimate the fungicide effective concentration (in milligrams per liter) that caused a 50% inhibition of fungal growth in vitro for all isolates. Significant temporal shifts were detected in the frequencies of sensitivity phenotypes to DMI and QoI but not organo-tin fungicides from 2016 through 2017. Individual isolates of Alternaria spp. were recovered with cross-resistance to DMI and multiple resistance to DMI, QoI, and triphenyltin hydroxide fungicides. To our knowledge, this is the first report of a fungus other than Cercospora beticola with resistance to organo-tin fungicides. Fungicide sensitivity monitoring indicates that an effective integrated disease management approach combining fungicide efficacy trials and monitoring pathogen biology is essential for developing effective resistance management recommendations.
Genome Sequencing and Transcriptome Analysis of the Hop Downy Mildew PathogenPseudoperonospora humuliReveal Species-Specific Genes for Molecular Detection
Authors: Rahman A. , Góngora-Castillo E. , Bowman M. J. , Childs K. L. , Gent D. H. , Martin F. N. , Quesada-Ocampo L. M.
Published: April 2019

Pseudoperonospora humuli is an obligate oomycete pathogen of hop (Humulus lupulus) that causes downy mildew, an important disease in most production regions in the Northern Hemisphere. The pathogen can cause a systemic infection in hop, overwinter in the root system, and infect propagation material. Substantial yield loss may occur owing to P. humuli infection of strobiles (seed cones), shoots, and cone-bearing branches. Fungicide application and cultural practices are the primary methods to manage hop downy mildew. However, effective, sustainable, and cost-effective management of downy mildew can be improved by developing early detection systems to inform on disease risk and timely fungicide application. However, no species-specific diagnostic assays or genomic resources are available for P. humuli. The genome of the P. humuli OR502AA isolate was partially sequenced using Illumina technology and assembled with ABySS. The assembly had a minimum scaffold length of 500 bp and an N50 (median scaffold length of the assembled genome) of 19.2 kbp. A total number of 18,656 genes were identified using MAKER standard gene predictions. Additionally, transcriptome assemblies were generated using RNA-seq and Trinity for seven additional P. humuli isolates. Bioinformatics analyses of next generation sequencing reads of P. humuli and P. cubensis (a closely related sister species) identified 242 candidate species-specific P. humuli genes that could be used as diagnostic molecular markers. These candidate genes were validated using polymerase chain reaction against a diverse collection of isolates from P. humuli, P. cubensis, and other oomycetes. Overall, four diagnostic markers were found to be uniquely present in P. humuli. These candidate markers identified through comparative genomics can be used for pathogen diagnostics in propagation material, such as rhizomes and vegetative cuttings, or adapted for biosurveillance of airborne sporangia, an important source of inoculum in hop downy mildew epidemics.
Cannabinoid hyperemesis syndrome
Authors: Smith Tiffany N. , Walsh Anne , Forest Christopher P.
Published: April 2019

Cannabis has long been used for medical and recreational purposes because of its antiemetic, analgesic, and mood effects. Ironically, chronic use of cannabis can result in paradoxical effects, including a condition known as cannabinoid hyperemesis syndrome. Patients with this syndrome often are seen in the ED with cyclic vomiting, nausea, and epigastric pain. Although the definitive treatment of cannabinoid hyperemesis syndrome is discontinuing the causative agent, medical management that includes rehydration is important to prevent complications. Common antiemetic medications are ineffective, but some studies have shown haloperidol and lorazepam to be effective in treating acute symptoms.
Using the 150 rule to prevent hepatotoxicity from acetaminophen
Authors: Nicholas William A. , Moore Randy
Published: April 2019

Acetaminophen-induced hepatotoxicity is the most common cause of acute liver failure in adults and a major cause of acute liver failure in children. Prompt treatment with N-acetylcysteine can mitigate hepatotoxicity and progression to liver failure. This article describes a 16-year-old girl who ingested a large dose of extra-strength acetaminophen, and how the 150 rule was used in her management.
Tranexamic Acid Use in Open Reduction and Internal Fixation of Fractures of the Pelvis, Acetabulum, and Proximal Femur: A Randomized Controlled Trial
Authors: Spitler Clay A. , Row Elliot R. , Gardner Warren E. , Swafford Rachel E. , Hankins Michael J. , Nowotarski Peter J. , Kiner Dirk W.
Published: April 2019

Objective:

To assess the safety and efficacy of tranexamic acid (TXA) use in fractures of the pelvic ring, acetabulum, and proximal femur.

Design:

Prospective, randomized controlled trial.

Setting:

Single Level 1 trauma center.

Patients:

Forty-seven patients were randomized to the study group, and 46 patients comprised the control group.

Intervention:

The study group received 15 mg/kg IV TXA before incision and a second identical dose 3 hours after the initial dose.

Main Outcome Measurements:

Transfusion rates and total blood loss (TBL) [via hemoglobin-dilution method and rates of venous thromboembolic events (VTEs)].

Results:

TBL was significantly higher in the control group (TXA = 952 mL, no TXA = 1325 mL, P = 0.028). The total transfusion rates between the TXA and control groups were not significantly different (TXA 1.51, no TXA = 1.17, P = 0.41). There were no significant differences between the TXA and control groups in inpatient VTE events (P = 0.57).

Conclusion:

The use of TXA in high-energy fractures of the pelvis, acetabulum, and femur significantly decreased calculated TBL but did not decrease overall transfusion rates. TXA did not increase the rate of VTE. Further study is warranted before making broad recommendations for the use of TXA in these fractures.

Level of Evidence:

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.