bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of terrestrial carbonaceous matter aromatization by Raman spectroscopy and its application to C chondrites
Authors: Schmidt Jaques S. , Hinrichs Ruth
Published: March 2020

A Raman method to estimate the aromatization degree of carbonaceous matter (CM) was established, and calibrated by literature data respecting differences in acquisition procedures. The generated equations allowed a comparison of the G‐band width to vitrinite reflectance, and to additional structural organization parameter extracted from X‐ray powder diffraction. The relations between aromatization degree and peak temperatures from literature were then propagated to G‐band width parameter. The applicability of these geothermometers is demonstrated by the consistency of data obtained for carbonaceous chondrites with previous estimations. Since the CM aromatization is controlled by peak temperature and time span, it is possible to estimate the duration of chondrite’s heating events. The G‐band width relation to elemental ratio trends of organic matter in chondrites, interplanetary dust particles, glucose, and saccharose‐based semi‐coke favors synthesis by formose route. These findings provide new approaches for the future development of chemical kinetic models for organic matter of chondrites. A reliable chemical model may allow the external calibration of numerical models for accurately evaluating the peak temperatures and cooling durations of chondrites.
Parentage analyses identify local dispersal events and sibling aggregations in a natural population of Millepora hydrocorals, a free‐spawning marine invertebrate
Authors: Dubé Caroline E. , Boissin Emilie , Mercière Alexandre , Planes Serge
Published: March 2020

Dispersal is a critical process for the persistence and productivity of marine populations. For many reef species, there is increasing evidence that local demography and self‐recruitment have major consequences on their genetic diversity and adaptation to environmental change. Yet empirical data of dispersal patterns in reef‐building species remain scarce. Here, we document the first genetic estimates of self‐recruitment and dispersal distances in a free‐spawning marine invertebrate, the hydrocoral Millepora cf. platyphylla. Using twelve microsatellite markers, we gathered genotypic information from 3,160 georeferenced colonies collected over 27,000 m2 of a single reef in three adjacent habitats in Moorea, French Polynesia; the mid slope, upper slope, and back reef. Although the adult population was predominantly clonal (85% were clones), our parentage analysis revealed a moderate self‐recruitment rate with a minimum of 8% of sexual propagules produced locally. Assigned offspring often settled at <10 m from their parents and dispersal events decrease with increasing geographic distance. There were no discrepancies between the dispersal distances of offspring assigned to parents belonging to clonal versus nonclonal genotypes. Interhabitat dispersal events via cross‐reef transport were also detected for sexual and asexual propagules. Sibship analysis showed that full siblings recruit nearby on the reef (more than 40% settled at <30 m), resulting in sibling aggregations. Our findings highlight the importance of self‐recruitment together with clonality in stabilizing population dynamics, which may ultimately enhance local sustainability and resilience to disturbance.
Patience is not always a virtue: effects of terrain complexity on the host‐seeking behaviour of adult blacklegged ticks, Ixodes scapularis, in the presence of a stationary host
Authors: Curtis T. R. , Shi M. , Qiao X.
Published: March 2020

Blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), are the primary vectors of Lyme disease in the U.S.A. In this study, adult ticks were observed on public trails exhibiting increasing levels of terrain complexity with a potential host nearby. The goal of this study was to (a) examine the extent to which adult ticks may actively search (vs. sit‐and‐wait) for a nearby host, (b) determine whether or not ticks could locate the position of the host in natural conditions and (c) determine the role of terrain complexity on the distances ticks travelled in a short period of time (30 min). Results indicate that, when a potential stationary host is within 50 cm, ticks will utilize an active‐search strategy. The majority of ticks moved in the direction of the host in natural conditions. Finally, ticks in a less complex terrain were more active and travelled greater horizontal distances than ticks in a more complex terrain. In conclusion, the use of an active‐search approach would likely increase the foraging success of ticks, especially in terrains with minimal complexity, near host animals that have stopped to rest or feed, reinforcing that humans should be vigilant about checking for ticks after being outdoors.
Phenotypic plasticity and community composition interactively shape trophic interactions
Authors: Start Denon
Published: March 2020

Trait variation defines and underpins biodiversity, yet we are only beginning to understand how processes acting across biological scales (individuals to whole communities) interact to produce trait differences and their consequences, particularly over short time scales. First, species often differ widely in their mean phenotype, meaning that changes in community composition can alter average trait values of a guild. Second, phenotypic plasticity alters the trait values of individuals, and the net effect of plasticity can also shift the average trait values of a specific species or of whole communities. However, community assembly, phenotypic plasticity, and their effects on biological patterns are not independent. The expression of phenotypic plasticity tends to be species‐specific, meaning that differences in species’ relative abundances will shape trait change and resulting ecological patterns and processes. I test this idea using mesocosms and simulations of communities of dragonfly larvae that differ in activity rate. Some but not all species reduced their activity rate in response to predation risk, causing larger trait‐mediated changes in trophic interactions in experimental communities dominated by plastic versus aplastic species. Using surveys and simulations of natural ponds, I demonstrate that community composition will shape patterns of phenotypic plasticity, with likely consequences for ecological dynamics in the wild. The interactive effects of trait differences across scales of biological organization necessitates an integrated view of diverse biological processes, including plasticity and community assembly, in order to understand ecological interactions.
STONE ‘CANVAS’ AND NATUFIAN ART: AN INCISED HUMAN FIGURE FROM THE NATUFIAN CEMETERY AT RAQEFET CAVE, ISRAEL
Authors: Rosenberg Danny , Chasan Rivka , Lengyel György , Nadel Dani
Published: March 2020

The Natufian culture is the first cultural entity in the southern Levant to have large graveyards and a wide array of symbolic expressions. Hundreds of Natufian burials have been discovered and studied; at some Natufian sites the presence of stone slabs within the graves has been recorded. One interesting yet rare phenomenon documented is the slabs bearing clear incised patterns, suggesting the Natufians were using these flat stone blocks as 'canvases'. Here we report and discuss an incised anthropomorphic figure that has been discovered in the Natufian graveyard at Raqefet Cave, Mt. Carmel, Israel. The human figure, most likely shown as dancing, adds another dimension to the rich assemblage of Natufian burial practices and symbolism as recorded at the site of Raqefet Cave as well as at other Natufian sites.
Trans‐myocardial bipolar electrogram: A strategy for mapping and determining efficacy of bipolar ablation of deep foci
Authors: Bokhari Mahmoud M. , Bhaskaran Abhishek , Gorth Gregory , Massé Stéphane , Downer Eugene , Nanthakumar Kumaraswamy
Published: March 2020

Mapping and ablation of intramural ventricular tachycardia (VT) remain a challenge. We developed a trans‐myocardial electrogram recording across distal tips of two separate ablation catheters placed on contralateral sides of the myocardium to record a trans‐myocardial bipole and a novel pacing electrode configuration. This trans‐myocardial bipole was applied during bipolar ablation in a patient with septal VT. Local activation in this trans‐myocardial bipole was similar to the earliest activation recorded from detailed activation maps from both sides of the septum. Pacing from this trans‐myocardial bipole resulted in a perfect morphology match. After bipolar ablation, the trans‐myocardial bipolar voltage decreased by 82%, and pacing threshold increased by 800%. These findings correlated with VT noninducibility.
Electric Shock: The 2012 India Blackout and Public Confidence in Politicians
Authors: Blankenship Brian , Urpelainen Johannes
Published: March 2020

How do disruptions in basic public service delivery shape people’s perceptions of politicians? We offer evidence from the July 2012 blackout in India, the largest in human history. Using data from the India Human Development Survey, we compare confidence in politicians between households that were surveyed during the outage and affected by it (treatment) and only days before it (control). Balance statistics show that the treatment and control groups are statistically indistinguishable, and further tests indicate that there was no disturbance to the pattern of surveying. Far from undermining public confidence in politicians, the outage increased it, as citizens reacted to the anxiety created by the crisis. The implications are normatively troubling, as politicians seem to have reaped benefits from disruptions in public service delivery.
HLA‐B*38:64, an HLA‐B*38 variant, detected in a Singaporean Malay unrelated hematopoietic stem cell donor
Authors: Cho Louise , Kaur Ashminder , Cereb Nezih , Lin Py‐Yu , Yang Kuo‐Liang
Published: March 2020

One nucleotide substitution in codon 89 of HLA‐B*38:02:01:01 results in a novel allele, HLA‐B*38:64.
Association between HLA‐DRB1*01 and HLA‐DRB1*15 with alloimmunisation in transfusion‐dependent patients with thalassaemia
Authors: Ebrahimi Mina , Dayer Dian , Jalalifar Mohammad Ali , Keikhaei Bijan , Tahan Nejad Asadi Zari
Published: March 2020

Background

Alloantibody production is one of the most challenging complications in transfusion‐dependent thalassaemia patients. Haemolytic anaemia, an increase in blood consumption, difficulty in haematopoietic stem cell transplantation and reduced quality of life are consequences of alloimmunisation. The most predisposed antigens (Ags) for alloantibody development are Rh and Kell blood group Ags.

Objective

The aim of the present study is to evaluate any correlation between HLA‐DRB1 alleles and Rh and Kell alloantibodies.

Materials and Methods

Fifty‐two non‐responders (control) and 54 responders (case) were enrolled in this study. Alloantibody detection was performed using the tube method. Genotyping of HLA‐DRB1*01 and HLA‐DRB1*15 was conducted by single‐specific primer‐polymerase chain reaction.

Results

In the responder group, 77.8% were hyper‐responders (more than one alloantibody), and only 22.2% were mono‐responders. Most detected alloantibodies were Anti‐K (94.4%), followed by Anti‐E (64.8%), Anti‐C (29.6%) and Anti‐D (25.9%). There was a significant difference in HLA‐DRB1*15 between responder and non‐responder groups, 73.7% vs 26.3%, respectively. (P = .029, OR = 3.290; 95%CI). Our results showed that HLA‐DRB1*15 was more frequent in hyper‐responders than mono‐responders (92.9% vs 7.1%) (P = .007). The greatest HLA‐DRB1*15 was seen in Anti‐K (P = .014, odds ratio [OR = 3.784]; 95% confidence interval [CI]) and Anti‐E (P = .011, OR = 3.609; 95%CI) alloantibodies. There is no association between HLA‐DRB1*01 and alloimmunisation.

Conclusion

Our findings showed that there is a significant correlation between HLA‐DRB1*15 and Anti‐K and Anti‐E alloantibodies. These findings can be useful in detecting susceptible thalassaemic patients and improving transfusion management.
The Other Metallic Phase in Spent Nuclear Fuel: A Complete Thermodynamic Evaluation of the U–Pd–Rh–Ru System
Authors: Wang Lian-Cheng , Kaye Matthew H.
Published: March 2020

During burnup of nuclear fuel, fission products accumulate. Post-irradiation examination of burned up nuclear fuel has revealed the presence of several phases, namely, the fuel matrix of UO2, with dissolved oxides present; a white metallic phase consisting of the so-called “noble metals” (i.e., Mo–Ru–Pd–Rh–Tc); a gray oxide phase consisting of alkali or alkaline earth oxides (e.g., BaZrO3 or Cs2UO4); and an another metallic inclusion containing a mixture of UPd3–URh3–URu3, which is not completely assessed due to the lack of phase diagrams of the UPd3–URh3, URh3–URu3, and UPd3–URu3. Understanding how these phases behave becomes especially important from a safety perspective, if one considers a potential accident scenario. The quaternary system U–Pd–Rh–Ru has been evaluated and a thermodynamic model has been developed by first considering the six binary subsystems and the four ternary subsystems. A critical examination of the U–Pd, U–Rh, and U–Ru experimental phase diagrams has been made, with attention placed on both the solution phases, generally present on the uranium side of the diagrams and the UPd3–URh3–URu3 compounds. Finally, the implications of this new model and its potential refinements of the Royal Military College of Canada nuclear fuel treatment developed by previous authors (notably the RMCC group under Thompson and Lewis) will be explored.
Multiphase Flow in Highly Fractured Shale Gas Reservoirs: Review of Fundamental Concepts for Numerical Simulation
Authors: Seales Maxian B.
Published: March 2020

Conventional hydrocarbon reservoirs, from an engineering and economic standpoint, are the easiest and most cost-efficient deposits to develop and produce. However, as economic deposits of conventional oil/gas become scarce, hydrocarbon recovered from tight sands and shale deposits will likely fill the void created by diminished conventional oil and gas sources. The purpose of this paper is to review the numerical methods available for simulating multiphase flow in highly fractured reservoirs and present a concise method to implement a fully implicit, two-phase numerical model for simulating multiphase flow, and predicting fluid recovery in highly fractured tight gas and shale gas reservoirs. The paper covers the five primary numerical modeling categories. It addresses the physical and theoretical concepts that support the development of numerical reservoir models and sequentially presents the stages of model development starting with mass balance fundamentals, Darcy’s law and the continuity equations. The paper shows how to develop and reduce the fluid transport equations. It also addresses equation discretization and linearization, model validation and typical model outputs. More advanced topics such as compositional models, reactive transport models, and artificial neural network models are also briefly discussed. The paper concludes with a discussion of field-scale model implementation challenges and constraints. The paper focuses on concisely and clearly presenting fundamental methods available to the novice petroleum engineer with the goal of improving their understanding of the inner workings of commercially available black box reservoir simulators. The paper assumes the reader has a working understanding of flow a porous media, Darcy’s law, and reservoir rock and fluid properties such as porosity, permeability, saturation, formation volume factor, viscosity, and capillary pressure. The paper does not explain these physical concepts neither are the laboratory tests needed to quantify these physical phenomena addressed. However, the paper briefly addresses these concepts in the context of sampling, uncertainty, upscaling, field-scale distribution, and the impact they have on field-scale numerical models.
Field emission from nanotubes and flakes of transition metal dichalcogenides
Authors: Ławrowski Robert , Pirker Luka , Kaneko Keita , Kokubo Hiroki , Bachmann Michael , Ikuno Takashi , Remskar Maja , Schreiner Rupert
Published: March 2020

Transition metal dichalcogenides such as MoS2 and WS2 are low-dimensional semiconductor materials. MoS2 and WS2 nanotubes and flakes were grown by a chemical transport reaction under a temperature gradient. I2 was used as a transport agent for previously synthesized MoS2 and WS2, respectively. These multilayered nanotubes are indirect bandgap semiconductors with a bandgap depending on their diameter. WS2 flakes were prepared by the sulfurization of thin WOx flakes. To increase the field enhancement of such low-dimensional structures by a higher aspect ratio, two approaches were examined: (a) the MoS2 and WS2 nanotubes were attached individually by a focused ion beam with Pt on dry etched n-type Si pillars and (b) the WS2 flakes were grown directly on the surface of the (n-type and p-type) Si pillars. Integral field emission measurements were performed in a diode configuration with a 50 μm mica spacer in a vacuum chamber at pressures of about 10−9 mbar. At a voltage of 900 V (18 MV/m), the integral emission current from the nanotubes is up to 11 μA for the lateral mounted MoS2 and about 1.3 μA (1.0 μA) for the upright mounted WS2 (MoS2). The onset voltage for a current of 1 nA is about 550 V for MoS2 and 500 V for WS2, respectively. The voltage conversion factor is in the range of 6 × 104–8 × 104 cm−1 for the nanotubes. The mounted MoS2 flakes show a field emission current of about 6 μA at 18 MV/m in contrast to the directly grown WS2 flakes, which show a pronounced saturation regime and, therefore, a lower emission current of about 0.5 μA is reached at 1500 V (25 MV/m). The WS2 flakes show a two times higher (1 × 105 cm−1) voltage conversion factor in comparison to the MoS2 flakes (5 × 104 cm−1). The extracted characteristics of the current-limiting part show a difference in the behavior of the extracted current-limiting characteristics between the lateral (linear) and upright mounted (exponential) nanotubes and the MoS2 flakes. In contrast, the WS2 flakes show charge carrier depletion effects.
Investigation of radiation damping in sandwich structures using finite and boundary element methods and a nonlinear eigensolver
Authors: Baydoun Suhaib Koji , Marburg Steffen
Published: March 2020

The fully coupled vibroacoustic interaction of sandwich panels is studied using the finite and the boundary element methods. The extent of radiation damping is quantified for various configurations based on both harmonic response analyses and modal analyses. The underlying nonlinear eigenvalue problem is solved using a projection method based on contour integration yielding the shifted (wet) eigenfrequencies, modal radiation loss factors, and air-loaded structural modes. The numerical results clearly illustrate the relevance of air-loading when studying the vibration of sandwich structures. Further, the numerically obtained estimates for radiation damping are compared to both theoretical expressions and experimental results found in the literature. Although good agreement is observed in general, the comparison indicates the limited applicability of commonly used theoretical expressions when coincidence occurs in a frequency range where the modes are still well separated. Moreover, possible sources of error when experimentally determining radiation damping are discussed in detail. The results presented in this paper provide deep insights into the phenomenon of acoustic radiation damping and help to estimate its relevance in future research.
Application of acoustical remote sensing techniques for ecosystem monitoring of a seagrass meadow
Authors: Ballard Megan S. , Lee Kevin M. , Sagers Jason D. , Venegas Gabriel R. , McNeese Andrew R. , Wilson Preston S. , Rahman Abdullah F.
Published: March 2020

Seagrasses provide a multitude of ecosystem services and serve as important organic carbon stores. However, seagrass habitats are declining worldwide, threatened by global climate change and regional shifts in water quality. Acoustical methods have been applied to assess changes in oxygen production of seagrass meadows since sound propagation is sensitive to the presence of bubbles, which exist both within the plant tissue and freely floating the water as byproducts of photosynthesis. This work applies acoustic remote sensing techniques to characterize two different regions of a seagrass meadow: a densely vegetated meadow of Thalassia testudinum and a sandy region sparsely populated by isolated stands of T. testudinum. A Bayesian approach is applied to estimate the posterior probability distributions of the unknown model parameters. The sensitivity of sound to the void fraction of gas present in the seagrass meadow was established by the narrow marginal probability distributions that provided distinct estimates of the void fraction between the two sites. The absolute values of the estimated void fractions are biased by limitations in the forward model, which does not capture the full complexity of the seagrass environment. Nevertheless, the results demonstrate the potential use of acoustical methods to remotely sense seagrass health and density.
Galacto- and Fructo-oligosaccharides Utilized for Growth by Cocultures of Bifidobacterial Species Characteristic of the Infant Gut
Authors: Sims Ian M. , Tannock Gerald W.
Published: March 2020

The kinds of bacteria that form the collection of microbes (the microbiota) in the gut of human infants may influence health and well-being. Knowledge of how the composition of the infant diet influences the assemblage of the bacterial collection is therefore important because dietary interventions may offer opportunities to alter the microbiota with the aim of improving health.
Bifidobacterium longum
subspecies
infantis
is a well-known bacterial species, but under modern child-rearing conditions it may be disadvantaged in the gut. Modern formula milks often contain particular oligosaccharide additives that are generally considered to support bifidobacterial growth. However, studies of the ability of various bifidobacterial species to grow together in the presence of these oligosaccharides have not been conducted. These kinds of studies are essential for developing concepts of microbial ecology related to the influence of human nutrition on the development of the gut microbiota.
Outbreak Severity of Highly Pathogenic Avian Influenza A(H5N8) Viruses Is Inversely Correlated to Polymerase Complex Activity and Interferon Induction
Authors: Vigeveno René M. , Poen Marjolein J. , Parker Edyth , Holwerda Melle , de Haan Karen , van Montfort Thijs , Lewis Nicola S. , Russell Colin A. , Fouchier Ron A. M. , de Jong Menno D. , Eggink Dirk
Published: March 2020

Compared to the 2014-15 outbreak, the 2016-17 outbreak of influenza A(H5N8) viruses in the Netherlands and Europe was more virulent; the number of dead or diseased wild birds found and the severity of pathological changes were higher during the 2016-17 outbreak. The polymerase complex plays an important role in influenza virus virulence, and the gene segments of influenza A(H5N8) viruses reassorted extensively between the outbreaks. In this study, the 2014-15 polymerase complexes were found to be more active, which is counterintuitive with the observed higher virulence of the 2016-17 outbreak viruses. Interestingly, the 2014-15 polymerase complexes also induced higher levels of IFN-β. These findings suggest that the higher virulence of influenza A(H5N8) viruses from the 2016-17 outbreak may be related to the lower induction of IFN-β. An attenuated interferon response could lead to increased dissemination, pathology, and mortality, as observed in (wild) birds infected during the 2016-2017 outbreak.
CD21 (Complement Receptor 2) Is the Receptor for Epstein-Barr Virus Entry into T Cells
Authors: Smith Nicholas A. , Coleman Carrie B. , Gewurz Benjamin E. , Rochford Rosemary
Published: March 2020

Epstein-Barr virus (EBV) has a well-described tropism for B cells and epithelial cells. Recently, we described the ability of a second strain of EBV, EBV type 2, to infect mature peripheral T cells. Using a neutralizing antibody assay, we determined that EBV uses the viral glycoprotein gp350 and the cellular protein CD21 to gain entry into mature peripheral T cells. CRISPR-Cas9 deletion of CD21 on the Jurkat T-cell line confirmed that CD21 is required for EBV infection. This study has broad implications, as we have defined a function for CD21 on mature peripheral T cells, i.e., as a receptor for EBV. In addition, the requirement for gp350 for T-cell entry has implications for EBV vaccine studies currently targeting the gp350 glycoprotein to prevent EBV-associated diseases.
Deletion of the Zinc Transporter Lipoprotein AdcAII Causes Hyperencapsulation of Streptococcus pneumoniae Associated with Distinct Alleles of the Type I Restriction-Modification System
Authors: Durmort Claire , Ercoli Giuseppe , Ramos-Sevillano Elisa , Chimalapati Suneeta , Haigh Richard D. , De Ste Croix Megan , Gould Katherine , Hinds Jason , Guerardel Yann , Vernet Thierry , Oggioni Marco , Brown Jeremy S.
Published: March 2020

The
Streptococcus pneumoniae
capsule affects multiple interactions with the host including contributing to colonization and immune evasion. During infection, the capsule thickness varies, but the mechanisms regulating this are poorly understood. We have identified an unsuspected relationship between mutation of
adcAII
, a gene that encodes a zinc uptake lipoprotein, and capsule thickness. Mutation of
adcAII
resulted in a striking hyperencapsulated phenotype, increased resistance to complement-mediated neutrophil killing, and increased
S. pneumoniae
virulence in mouse models of infection. Transcriptome and PCR analysis linked the hyperencapsulated phenotype of the
ΔadcAII
strain to specific alleles of the SpnD39III (ST5556II) type I restriction-modification system, a system which has previously been shown to affect capsule thickness. Our data provide further evidence for the importance of the SpnD39III (ST5556II) type I restriction-modification system for modulating capsule thickness and identify an unexpected link between capsule thickness and
ΔadcAII
, further investigation of which could further characterize mechanisms of capsule regulation.
Epistatic Interplay between Type IV Secretion Effectors Engages the Small GTPase Rab2 in the
Brucella
Intracellular Cycle
Authors: Smith Erin P. , Cotto-Rosario Alexis , Borghesan Elizabeth , Held Kiara , Miller Cheryl N. , Celli Jean
Published: March 2020

Bacterial pathogens with an intracellular lifestyle modulate many host cellular processes to promote their infectious cycle. They do so by delivering effector proteins into host cells via dedicated secretion systems that target specific host functions. While the roles of many individual effectors are known, how their modes of action are coordinated is rarely understood. Here, we show that the zoonotic bacterium
Brucella abortus
delivers the BspB effector that mitigates the negative effect on bacterial replication that the RicA effector exerts via modulation of the host small GTPase Rab2. These findings provide an example of functional integration between bacterial effectors that promotes proliferation of pathogens.
Bacillus anthracis Responds to Targocil-Induced Envelope Damage through EdsRS Activation of Cardiolipin Synthesis
Authors: Laut Clare L. , Perry William J. , Metzger Alexander L. , Weiss Andy , Stauff Devin L. , Walker Suzanne , Caprioli Richard M. , Skaar Eric P.
Published: March 2020

Compromising the integrity of the bacterial cell barrier is a common action of antimicrobials. Targocil is an antimicrobial that is active against the bacterial envelope. We hypothesized that
Bacillus anthracis
, a potential weapon of bioterror, senses and responds to targocil to alleviate targocil-dependent cell damage. Here, we show that targocil treatment increases the permeability of the cellular envelope and is particularly toxic to
B. anthracis
spores during outgrowth. In vegetative cells, two-component system signaling through EdsRS is activated by targocil. This results in an increase in the production of cardiolipin via a cardiolipin synthase, ClsT, which restores the loss of barrier function, thereby reducing the effectiveness of targocil. By elucidating the
B. anthracis
response to targocil, we have uncovered an intrinsic mechanism that this pathogen employs to resist toxicity and have revealed therapeutic targets that are important for bacterial defense against structural damage.
Recovery of lacustrine ecosystems after the end-Permian mass extinction
Authors: Zhao Xiangdong , Zheng Daran , Xie Guwei , Jenkyns Hugh C. , Guan Chengguo , Fang Yanan , He Jing , Yuan Xiaoqi , Xue Naihua , Wang He , Li Sha , Jarzembowski Edmund A. , Zhang Haichun , Wang Bo
Published: March 2020

The end-Permian mass extinction (EPME; ca. 252 Ma) led to profound changes in lacustrine ecosystems. However, whether or not post-extinction recovery of lacustrine ecosystems was delayed has remained uncertain, due to the apparent rarity of Early and Middle Triassic deep perennial lakes. Here we report on mid–Middle Triassic lacustrine organic-rich shales with abundant fossils and tuff interlayers in the Ordos Basin of China, dated to ca. 242 Ma (around the Anisian-Ladinian boundary of the Middle Triassic). The organic-rich sediments record the earliest known appearance, after the mass extinction, of a deep perennial lake that developed at least 5 m.y. earlier than the globally distributed lacustrine shales and mudstones dated as Late Triassic. The fossil assemblage in the organic-rich sediments is diverse and includes plants, notostracans, ostracods, insects, fishes, and fish coprolites, and thus documents a Mesozoic-type, trophically multileveled lacustrine ecosystem. The results reveal the earliest known complex lacustrine ecosystem after the EPME and suggest that Triassic lacustrine ecosystems took at most 10 m.y. to recover fully, which is consistent with the termination of the “coal gap” that signifies substantial restoration of peat-forming forests.
The impact of gender equity in agriculture on nutritional status, diets, and household food security: a mixed-methods systematic review
Authors: Harris-Fry Helen , Nur Hayaan , Shankar Bhavani , Zanello Giacomo , Srinivasan Chittur , Kadiyala Suneetha
Published: March 2020

Introduction

Undernutrition rates remain high in rural, low-income settings, where large, gender-based inequities persist. We hypothesised that increasing gender equity in agriculture could improve nutrition.

Methods

We conducted a systematic review to assess the associations between gender-based inequities (in income, land, livestock, and workloads) and nutrition, diets and food security outcomes in agricultural contexts of low-income and middle-income countries. Between 9 March and 7 August 2018, we searched 18 databases and 14 journals, and contacted 27 experts. We included quantitative and qualitative literature from agricultural contexts in low-income and middle-income countries, with no date restriction. Outcomes were women’s and children’s anthropometric status, dietary quality and household food security. We conducted meta-analyses using random-effects models.

Results

We identified 19 820 records, of which 34 studies (42 809 households) met the inclusion criteria. Most (22/25) quantitative studies had a high risk of bias, and qualitative evidence was of mixed quality. Income, land and livestock equity had heterogeneous associations with household food security and child anthropometric outcomes. Meta-analyses showed women’s share of household income earned (0.32, 95% CI −4.22 to 4.86; six results) and women’s share of land owned (2.72, 95% CI -0.52 to 5.96; three results) did not increase the percentage of household budget spent on food. Higher-quality studies showed more consistently positive associations between income equity and food security. Evidence is limited on other exposure–outcome pairings.

Conclusions

We find heterogeneous associations between gender equity and household-level food security. High-quality research is needed to establish the impact of gender equity on nutrition outcomes across contexts.

PROSPERO registration number

CRD42018093987.
Identifying alternative models of healthcare service delivery to inform health system improvement: scoping review of systematic reviews
Authors: Jessup Rebecca , Putrik Polina , Buchbinder Rachelle , Nezon Janet , Rischin Kobi , Cyril Sheila , Shepperd Sasha , O’Connor Denise A
Published: March 2020

Objective

To describe available evidence from systematic reviews of alternative healthcare delivery arrangements relevant to high-income countries to inform decisions about healthcare system improvement.

Design

Scoping review of systematic reviews.

Data sources

Systematic reviews of interventions indexed in Pretty Darn Quick-Evidence.

Eligibility criteria

All English language systematic reviews evaluating the effects of alternative delivery arrangements relevant to high-income countries, published between 1 January 2012 and 20 September 2017. Eligible reviews had to summarise evidence on at least one of the following outcomes: patient outcomes, quality of care, access and/or use of healthcare services, resource use, impacts on equity and/or social outcomes, healthcare provider outcomes or adverse effects.

Data extraction and synthesis

Journal, publication year, number and design of primary studies, populations/health conditions represented and types of outcomes were extracted.

Results

Of 829 retrieved records, 531 reviews fulfilled our inclusion criteria. Almost all (93%) reviews reported on patient outcomes, while only about one-third included resource use as an outcome of interest. Just over a third (n=189, 36%) of reviews focused on alternative information and communications technology interventions (including 162 reviews on telehealth). About one-quarter (n=122, 23%) of reviews focused on alternative care coordination interventions. 15% (n=80) of reviews examined interventions involving changes to who provides care and how the healthcare workforce is managed. Few reviews investigated the effects of interventions involving changes to how and when care is delivered (n=47, 9%) or interventions addressing a goal-focused question (n=38, 7%).

Conclusion

A substantial body of evidence about the effects of a wide range of delivery arrangements is available to inform health system improvements. The lack of economic evaluations in the majority of systematic reviews of delivery arrangements means that the value of many of these models is unknown. This scoping review identifies evidence gaps that would be usefully addressed by future research.
‘Real time’ monitoring of antipsychotic prescribing in patients with dementia: a study using the Clinical Record Interactive Search (CRIS) platform to enhance safer prescribing
Authors: Colling Craig , Mueller Christoph , Perera Gayan , Funnell Nicola , Sauer Justin , Harwood Daniel , Stewart Robert , Bishara Delia
Published: March 2020

Background

The use of antipsychotic drugs in dementia has been reported to be associated with increased risk of cerebrovascular events and mortality. There is an international drive to reduce the use of these agents in patients with dementia and to improve the safety of prescribing and monitoring in this area.

Objectives

The aim of this project was to use enhanced automated regular feedback of information from electronic health records to improve the quality of antipsychotic prescribing and monitoring in people with dementia.

Methods

The South London and Maudsley NHS Foundation Trust (SLaM) incorporated antipsychotic monitoring forms into its electronic health records. The SLaM Clinical Record Interactive Search (CRIS) platform provides researcher access to de-identified health records, and natural language processing is used in CRIS to derive structured data from unstructured free text, including recorded diagnoses and medication. Algorithms were thus developed to ascertain patients with dementia receiving antipsychotic treatment and to determine whether monitoring forms had been completed. We used two improvement plan-do-study-act cycles to improve the accuracy of the algorithm for automated evaluation and provided monthly feedback on team performance.

Results

A steady increase in antipsychotic monitoring form completion was observed across the study period. The percentage of our sample with a completed antipsychotic monitoring form more than doubled from October 2017 (22%) to January 2019 (58%).

Conclusion

‘Real time’ monitoring and regular feedback to teams offer a time-effective approach, complementary to standard audit methods, to enhance the safer prescribing of high risk drugs.
Elite coaches have a similar prevalence of depressive symptoms to the general population and lower rates than elite athletes
Authors: Kim Simon Sang Yeob , Hamiliton Bruce , Beable Sarah , Cavadino Alana , Fulcher Mark L
Published: March 2020

Objective

The primary aim of this study was to estimate the prevalence of depressive symptoms and life stress in elite coaches. The secondary aim was to explore the associations of depressive symptoms and life stress with demographic and lifestyle variables.

Methods

National-level coaches were invited to participate in an online survey. Depressive symptoms were measured by the Centre for Epidemiological Studies Depression Scale-Revised (CESD-R). Life stress was measured using daily life hassle frequency and severity scores calculated from the Daily Hassles Questionnaire, with associations evaluated using linear regression.

Results

Of 110 potential participants, 69 completed and two partially completed surveys were received. The majority of respondents were male (77%), coaching individual sports (70%) and aged under 50 (71%). Overall, 14% of coaches reported at least moderate depressive symptoms according to the CESD-R. Those contemplating retirement were more likely to show depressive symptoms. Reported life stress was higher in females and in those contemplating retirement. There was a strong association between life stress and the odds of experiencing depressive symptoms (p=0.006).

Conclusions

Depressive symptoms are as prevalent in elite coaches as in general population, with potential risk factors including high levels of life stress and impending retirement.
Four types of gender bias affecting women surgeons and their cumulative impact
Authors: Hutchison Katrina
Published: March 2020

Women are under-represented in surgery, especially in leadership and academic roles, and face a gender pay gap. There has been little work on the role of implicit biases in women’s under-representation in surgery. Nor has the impact of epistemic injustice, whereby stereotyping influences knowledge or credibility judgements, been explored. This article reports findings of a qualitative in-depth interview study with women surgeons that investigates gender biases in surgery, including subtle types of bias. The study was conducted with 46 women surgeons and trainees of the Royal Australasian College of Surgeons. Maximum variance sampling strategies ensured a comprehensive set of perspectives. Data were analysed using iterative thematic analysis to document and classify forms of gender bias experienced by the participants, including implicit bias and epistemic injustice. It found four types of bias affecting women surgeons: (1) workplace factors such as access to parental leave and role models; (2) epistemic injustices—unfair assessments of women surgeons’ credibility by patients and colleagues; (3) stereotyped expectations that they will carry out more of surgery’s carework, such as meeting the emotional needs of patients and (4) objectification. Implicit biases arose in each category. Given that many of the biases identified in this study are small, are harmless on their own and are not necessarily under anyone’s conscious control, important questions arise regarding how they cause harm and how to address them. I draw on theoretical work on cumulative harm to answer these questions.
Augmented reality in surgical training: a systematic review
Authors: Williams Matthew Adam , McVeigh James , Handa Ashok Inderraj , Lee Regent
Published: March 2020

The aim of this systematic review is to provide an update on the current state of augmented reality (AR) in surgical training and to further report on any described benefits compared with traditional techniques. A PICO (Population, Intervention, Comparison, Outcome) strategy was adopted to formulate an appropriate research question and define strict search terms to be entered into MEDLINE, CENTRAL and Google Scholar. The search was returned on 12/09/2019. All returned results were screened first by title and then abstract. The systematic search returned a total of 236 results, of which 18 were selected for final inclusion. Studies covered the full range of surgical disciplines and reported on outcomes including operative duration, accuracy and postoperative complication rates. Due to the heterogeneity of the collected data, no meta-analysis was possible. Outcome measures of competency, surgical opinion and postoperative complication rate were in favour of AR technology while operative duration appears to increase.
Big data and artificial intelligence discover novel drugs targeting proteins without 3D structure and overcome the undruggable targets
Authors: He Huiqin , Liu Benquan , Luo Hongyi , Zhang Tingting , Jiang Jingwei
Published: March 2020

The discovery of targeted drugs heavily relies on three-dimensional (3D) structures of target proteins. When the 3D structure of a protein target is unknown, it is very difficult to design its corresponding targeted drugs. Although the 3D structures of some proteins (the so-called undruggable targets) are known, their targeted drugs are still absent. As increasing crystal/cryogenic electron microscopy structures are deposited in Protein Data Bank, it is much more possible to discover the targeted drugs. Moreover, it is also highly probable to turn previous undruggable targets into druggable ones when we identify their hidden allosteric sites. In this review, we focus on the currently available advanced methods for the discovery of novel compounds targeting proteins without 3D structure and how to turn undruggable targets into druggable ones.
Strength development of cemented tailings materials containing polycarboxylate ether-based superplasticizer: experimental results on the effect of time and temperature
Authors: Haruna Sada , Fall Mamadou
Published: March 2020

Superplasticizers are widely used in the backfill industry for the improvement of the flow ability of cemented paste backfill (CPB) while keeping water content low. However, the coupled effects of temperature and curing time on the mechanical strength of CPB with superplasticizers are poorly understood. This paper presents new findings of research conducted to experimentally assess the effects of a polycarboxylate-based superplasticizer on the strength of CPB subjected to varying curing time (1, 3, 7, and 28 days) and temperature (2 °C, 20 °C, and 35 °C). The binders used were Portland cement type I, fly ash, and blast furnace slag. Superplasticizer contents of 0, 0.125, and 0.25 percent of the total weight of the CPB were added. Various microstructural analyses and monitoring programs were also conducted to understand the principles behind the patterns in the strength of different CPB samples. The results obtained show that the unconfined compressive strength (UCS) of the CPB containing polycarboxylate-based superplasticizer increases with time. Moreover, the increase in superplasticizer content was observed to improve the UCS of the CPB (0.25% > 0.125% > 0%). The temperature was also observed to play an important role in strength development as the UCS increases with the rise in the curing temperature for all samples. It is also found that the temperature-induced strength increase is more significant for the CPBs that contain the superplasticizer than for those without superplasticizer. It was also observed that the CPB containing superplasticizer maintained a relatively similar strength upon replacing the cement with 50% slag while showing a sharp decline with fly ash. The findings from this study will be useful towards a cost-effective design of backfill structures.
Timing of Cache Creek Ocean closure: insights from new Jurassic radiolarian ages in British Columbia and Yukon and their significance for Canadian Cordillera tectonics
Authors: Cordey Fabrice
Published: March 2020

The closure of the Cache Creek Ocean during the Jurassic led to the structuration of the Canadian Cordillera. To reassess the timing of this major tectonic event, this study proposes a biochronological review of all the youngest radiolarian-bearing localities of the Cache Creek Terrane in British Columbia and Yukon using updated radiolarian biozonations and taxonomy, complemented by new data from the type locality. The results show that all ages are Early Jurassic and fairly homogenous along the entire terrane. All the youngest siliceous rocks are restricted to the late Sinemurian – early Toarcian interval (∼195–180 Ma). The youngest well-dated pelagic cherts are early Pliensbachian, with slightly younger siliceous argillites of Pliensbachian and possibly early Toarcian age. These results suggest that Cache Creek deep pelagic sedimentation ceased fairly synchronously along the entire belt, probably during the Pliensbachian (∼191–183 Ma), predating the final closure of the basin when Cache Creek units were thrust over Stikinia and Quesnellia in the Middle and Late Jurassic. This apparent synchronicity should result in re-evaluating the tectonic mechanism of the Cache Creek “entrapment model” in its present form. The study also shows that pelagic sedimentation ceased 22–31 million years earlier in the Cache Creek Terrane than in the Bridge River Terrane, confirming the stratigraphic discrepancy between the two terranes during the Jurassic.
Interactions of metal-based nanoparticles (MBNPs) and metal-oxide nanoparticles (MONPs) with crop plants: a critical review of research progress and prospects
Authors: Liu Weitao , Zeb Aurang , Lian Jiapan , Wu Jiani , Xiong Hongxia , Tang Jingchun , Zheng Shunan
Published: March 2020

Over the past decade, the production and applications of metal-based and metal-oxide nanoparticles (MBNPs and MONPs, respectively) have increased significantly due to their enhanced physicochemical properties and biological activities when compared with their bulk parent materials. Once MBNPs and MONPs enter agricultural soil via direct or indirect pathways, they can interact with crop plants and thus pose a threat to both animal and human health through food chain pathways. Although many review articles on engineered nanoparticles have been published, few have focused on the interactions of MBNPs and MONPs with crop plants and their current applications. Therefore, we reviewed the sources and behaviors of MBNPs and MONPs in agricultural soil, physiological and biochemical effects of MBNPs and MONPs on plants, uptake, translocation of MBNPs and MONPs in crop plants, factors affecting the interaction between MBNPs and MONPs and plants, and the applications of MBNPs and MONPs. Lastly, we propose where the future research priorities should be focused to provide a better understanding of MBNPs and MONPs. This review will help to promote scientific research regarding MBNPs and MONPs and to understand the risks and benefits of their association with plants and will contribute to the advancement of nanotechnology.