bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional connectivity in replicated urban landscapes in the land snail (Cornu aspersum)
Authors: Balbi Manon , Ernoult Aude , Poli Pedro , Madec Luc , Guiller Annie , Martin Marie‐Claire , Nabucet Jean , Beaujouan Véronique , Petit Eric J.
Published: February 2018

Urban areas are highly fragmented and thereby exert strong constraints on individual dispersal. Despite this, some species manage to persist in urban areas, such as the garden snail, Cornu aspersum, which is common in cityscapes despite its low mobility. Using landscape genetic approaches, we combined study area replication and multiscale analysis to determine how landscape composition, configuration and connectivity influence snail dispersal across urban areas. At the overall landscape scale, areas with a high percentage of roads decreased genetic differentiation between populations. At the population scale, genetic differentiation was positively linked with building surface, the proportion of borders where wooded patches and roads appeared side by side and the proportion of borders combining wooded patches and other impervious areas. Analyses based on pairwise genetic distances validated the isolation‐by‐distance and isolation‐by‐resistance models for this land snail, with an equal fit to least‐cost paths and circuit‐theory‐based models. Each of the 12 landscapes analysed separately yielded specific relations to environmental features, whereas analyses integrating all replicates highlighted general common effects. Our results suggest that urban transport infrastructures facilitate passive snail dispersal. At a local scale, corresponding to active dispersal, unfavourable habitats (wooded and impervious areas) isolate populations. This work upholds the use of replicated landscapes to increase the generalizability of landscape genetics results and shows how multiscale analyses provide insight into scale‐dependent processes.
Leishmania mexicana can utilize amino acids as major carbon sources in macrophages but not in animal models
Authors: Saunders Eleanor C. , Naderer Thomas , Chambers Jenny , Landfear Scott M. , McConville Malcolm J.
Published: February 2018

Leishmania parasites target macrophages in their mammalian hosts and proliferate within the mature phagolysosome compartment of these cells. Intracellular amastigote stages are dependent on sugars as a major carbon source in vivo, but retain the capacity to utilize other carbon sources. To investigate whether amastigotes can switch to using other carbon sources, we have screened for suppressor strains of the L. mexicana Δlmxgt1‐3 mutant which lacks the major glucose transporters LmxGT1‐3. We identified a novel suppressor line (Δlmxgt1‐3s2) that has restored growth in rich culture medium and virulence in ex vivo infected macrophages, but failed to induce lesions in mice. Δlmxgt1‐3s2 amastigotes had lower rates of glucose utilization than the parental line and primarily catabolized non‐essential amino acids. The increased mitochondrial metabolism of this line was associated with elevated levels of intracellular reactive oxygen species, as well as increased sensitivity to inhibitors of the tricarboxylic acid (TCA) cycle, including nitric oxide. These results suggest that hardwired sugar addiction of Leishmania amastigotes contributes to the intrinsic resistance of this stage to macrophage microbicidal processes in vivo, and that these stages have limited capacity to switch to using other carbon sources.
Regional productivity mediates the effects of grazing disturbance on plant cover and patch‐size distribution in arid and semi‐arid communities
Authors: Oñatibia Gastón R. , Boyero Luciano , Aguiar Martín R.
Published: February 2018

Patch‐size distribution and plant cover are strongly associated to arid ecosystem functioning and may be a warning signal for the onset of desertification under changes in disturbance regimes. However, the interaction between regional productivity level and human‐induced disturbance regime as drivers for vegetation structure and dynamics remain poorly studied. We studied grazing disturbance effects on plant cover and patchiness in three plant communities located along a regional productivity gradient in Patagonia (Argentina): a semi‐desert (low‐productivity community), a shrub‐grass steppe (intermediate‐productivity community) and a grass steppe (high‐productivity community). We sampled paddocks with different sheep grazing pressure (continuous disturbance gradients) in all three communities. In each paddock, the presence or absence of perennial vegetation was recorded every 10 cm along a 50 m transect. Grazing effects on vegetation structure depended on the community and its association to the regional productivity. Grazing decreased total plant cover while increasing both the frequency of small patches and the inter‐patch distance in all communities. However, the size of these effects was the greatest in the high‐productivity community. Dominant species responses to grazing explained vegetation patch‐ and inter‐patch‐size distribution patterns. As productivity decreases, dominant species showed a higher degree of grazing resistance, probably because traits of species adapted to high aridity allow them to resist herbivore disturbance. In conclusion, our findings suggest that regional productivity mediates grazing disturbance impacts on vegetation mosaic. The changes within the same range of grazing pressure have higher effects on communities found in environments with higher productivity, markedly promoting their desertification. Understanding the complex interactions between environmental aridity and human‐induced disturbances is a key aspect for maintaining patchiness structure and dynamics, which has important implications for drylands management.
Is sexual organ reciprocity related to legitimate pollen deposition in distylous Pulmonaria (Boraginaceae)?
Authors: Jacquemyn Hans , Gielen Marie , Brys Rein
Published: February 2018

Heterostyly, i.e. the reciprocal positioning of anthers and stigmas, is a floral polymorphism that is thought to promote disassortative (i.e. between‐morph) pollination and to maintain genetic diversity within populations. Recent research, however, has shown several cases of heterostylous plant species in which the reciprocal positioning of the sexual organs varies, which may affect the likelihood of ‘legitimate’ pollination between compatible morphs, and hence morph fitness and ultimately the stability of this floral polymorphism. In this study, we investigated floral morphology and stigmatic pollen deposition patterns in nine Pulmonaria species (Boraginaceae) across Europe to test the hypothesis that sexual organ reciprocity is related to legitimate pollen deposition. We used a recently developed adaptive accuracy concept to assess the level of reciprocity and to relate inaccuracies in positioning of sexual organs to legitimate pollen deposition measured on stigmas in the field. The nine investigated Pulmonaria species showed substantial deviations from perfect reciprocity, with total inaccuracies varying between 2.9 and 20.3% relative to the squared mean of all anther and stigma heights in the population. In almost all cases, most of the inaccuracy was generated by the high‐level organs. Total pollen deposition was always higher on stigmas of long‐styled individuals, but stigmas of short‐styled individuals received significantly more legitimate pollen than stigmas of long‐styled individuals (71.23% and 38.75% respectively). We also found a weak but significant relationship between measures of inaccuracy and the level of disassortative pollination. Under these conditions of pollen flow, the distylous mating system is predicted to persist in only eleven (27%) of all sampled populations. Overall, these results indicate that deviations from perfect reciprocal herkogamy are common in Pulmonaria and have an impact on legitimate pollen deposition.
Organizational reputation and risk regulation: The effect of reputational threats on agency scientific outputs
Authors: Rimkutė Dovilė
Published: February 2018

This article aims to explain the variation in the scientific risk assessments conducted by two regulatory agencies: the European Food Safety Authority (EFSA) and the French Agency for Food, Environmental and Occupational Health and Safety (ANSES). To explain the merits of scientific risk assessments that have caused polarization within the EU, this article draws on bureaucratic reputation theory. The theory argues that regulators are political organizations that are active in protecting their unique organizational reputations. The findings obtained from interviews, direct observations, and primary documents yield support for this framework: depending on reputational threats, agencies choose to emphasize either their role as guardians of the prevailing social values, or send strong professional signals by delivering a scientifically rigorous risk assessment.
Host response genes associated with nodular gastritis in Helicobacter pylori infection
Authors: Ikuse Tamaki , Ohtsuka Yoshikazu , Obayashi Naho , Jimbo Keisuke , Aoyagi Yo , Kudo Takahiro , Asaoka Daisuke , Hojo Mariko , Nagahara Akihito , Watanabe Sumio , Blanchard Thomas G , Czinn Steven J , Shimizu Toshiaki
Published: February 2018

Background

Chronic Helicobacter pylori infection in children induces lymphoid hyperplasia called nodular gastritis (NG) at the antral gastric mucosa. The aim of this study was to evaluate genes in gastric biopsy on microarray analysis, to identify molecules associated with NG on comparison with NG‐negative pediatric corpus tissue and with H. pylori‐infected adult tissue with atrophic gastritis (AG).

Methods

Eight pediatric and six adult H. pylori‐infected patients, as well as six pediatric and six adult uninfected patients were evaluated. All infected adults had AG. NG was observed in the antrum of all eight pediatric patients and in the corpus of three patients. Adult and uninfected patients were free of NG; that is, only pediatric H. pylori‐infected patients had NG. Total RNA was purified from gastric biopsy, and microarray analysis was performed to compare gene expression between groups. The three infected children with NG in both the antrum and corpus were excluded from analysis of corpus samples.

Results

The number of genes significantly up‐ or downregulated (fold change >3, P < 0.01) compared with uninfected controls varied widely: 72 in pediatric antrum, 45 in pediatric corpus, 103 in adult antrum and 71 in adult corpus. Nineteen genes had significantly altered expression in the antrum of NG tissue compared with NG‐negative pediatric corpus tissue and adult AG tissue. The CD20 B‐cell specific differentiation antigen had the most pronounced increase. Previously described regulators of NG development were not predominantly upregulated in the NG mucosa.

Conclusions

CD20 overexpression may play an important role in lymphoid follicle enlargement and NG.
Incidence, risk factors, and outcomes related with neurological events after liver transplantation in adult and pediatric recipients
Authors: Piñero Federico , Cheang Yu , Mendizabal Manuel , Cagliani Joaquín , Gonzalez Campaña Ariel , Pages Josefina , Colaci Carla , Barreiro Mariano , Alonso Cristina , Malla Ivone , Fauda Martín , Bueri Jose , Podesta Luis G , Silva Marcelo
Published: February 2018

Controversy exists whether NE after LT are more frequently observed in children or adults. We aimed to compare the incidence and outcomes for NE after LT in pediatric and adult recipients. A single‐center cohort study, including all LT between 2001 and 2013, was performed. Definition of NE included impaired consciousness, delirium, seizures, focal neurologic deficit, visual impairment, or slurred speech. A cohort of 443 consecutive LT recipients was included: 307 adults and 136 children. Cumulative incidence of NE was similar between adults 15% (n = 41) and children 16% (n = 20; P = .73) with a complete neurological recovery in 62% and 95% of the patients, respectively (P < .0001). Adults with NE had significantly lower survival (70% vs 76%; P = .015) with a HR of 2.36; this was similarly observed in children (45% vs 66%; HR 2.05, CI 0.66; 6.34). Independent risk factors for NE in adults were pre‐LT ascites, delta sodium, and post‐LT hypomagnesemia, whereas in children pre‐LT encephalopathy ≥II and serum albumin were associated with NE. Although a similar incidence of NE after LT was observed, children were more likely to achieve neurological recovery. Risk factors for the development of NE are difficult to assess in both populations.
Cellulose synthesis during cell plate assembly
Authors: Chen Hsiang‐Wen , Persson Staffan , Grebe Markus , McFarlane Heather E.
Published: February 2018

The plant cell wall surrounds and protects the cells. To divide, plant cells must synthesize a new cell wall to separate the two daughter cells. The cell plate is a transient polysaccharide‐based compartment that grows between daughter cells and gives rise to the new cell wall. Cellulose constitutes a key component of the cell wall, and mutants with defects in cellulose synthesis commonly share phenotypes with cytokinesis‐defective mutants. However, despite the importance of cellulose in the cell plate and the daughter cell wall, many open questions remain regarding the timing and regulation of cellulose synthesis during cell division. These questions represent a critical gap in our knowledge of cell plate assembly, cell division and growth. Here, we review what is known about cellulose synthesis at the cell plate and in the newly formed cross‐wall and pose key questions about the molecular mechanisms that govern these processes. We further provide an outlook discussing outstanding questions and possible future directions for this field of research.
Phosphorus‐ and nitrogen‐acquisition strategies in two Bossiaea species (Fabaceae) along retrogressive soil chronosequences in south‐western Australia
Authors: Abrahão Anna , Ryan Megan H. , Laliberté Etienne , Oliveira Rafael S. , Lambers Hans
Published: February 2018

During long‐term ecosystem development and its associated decline in soil phosphorus (P) availability, the abundance of mycorrhizal plant species declines at the expense of non‐mycorrhizal species with root specialisations for P‐acquisition, such as massive exudation of carboxylates. Leaf manganese (Mn) concentration has been suggested as a proxy for such a strategy, Mn concentration being higher in non‐mycorrhizal plants that release carboxylates than in mycorrhizal plants. Shifts in nitrogen (N)‐acquisition strategies also occur; nodulation in legumes is expected at low N availability, when sufficient P is available. We investigated whether two congeneric legume species (Bossiaea linophylla and Bossiaea eriocarpa) occurring along two long‐term chronosequences on the south‐western Australian coast and grown in a glasshouse at varying N and P supply exhibited plasticity in nutrient‐acquisition strategies. We hypothesised that the shifts in nutrient limitation and nutrient‐acquisition strategies at the community level would also be found at the species level. Leaf N: P ratios and the responses to nutrient availability suggested that growth of both species exhibited P‐limitation in all treatments, due to the very high leaf [N] of legumes afforded by symbiotic N‐fixation. Mycorrhizal colonisation was not greater at higher P supply, and root exudation of carboxylates was not stimulated at low P supply; both were unrelated to leaf [Mn]. However, nodule production declined with increasing N supply. We conclude that intraspecific variation in nutrient‐acquisition and use is low in these species, and that the variation at the community level, observed in previous studies, is likely driven by high‐species turnover.
Ideals and pragmatism in the justification of ecological restoration
Authors: Hertog Iris M. , Turnhout Esther
Published: February 2018

Ecological restoration requires value‐laden choices about what goals, references, and methods to use in a particular area. The restoration ecology literature has identified a number of interrelated dilemmas pertaining among others to the use of historical references or the creation of novel ecosystems and to the selection of appropriate measures of intervention. In this study, we investigate the narratives that Dutch professionals in ecological restoration use to justify these choices and we analyze the values, beliefs, and human‐nature relationships they reflect. Based on our analysis, we identify three interrelated sets of values, beliefs, and human‐nature relationships, which we call here narrative clusters. These are: (1) virtuous stewardship, which foregrounds human responsibility to care for nature; (2) autonomous nature, which foregrounds the self‐regulating capacities of nature; and (3) pragmatic wise use, which foregrounds the use of nature by humans and the importance of practical considerations. These narrative clusters connect well with established sociological and philosophical classifications of nature and human‐nature relationships. However, our analysis also shows that in the navigation of the different dilemmas of conservation, practitioners draw on a wide variety of arguments to justify their practices. In doing so, they blur the boundaries between different views of nature, between ethical and pragmatic arguments, and between nature and culture. We conclude the article by reflecting on the implications of these findings for the conceptualization and practice of restoration.
Agriculture in Shifting Climates: The Configuration and Ripeness of Problem Understandings in Uganda and Senegal
Authors: Raile Eric D. , Young Linda M. , Bonabana‐Wabbi Jackline , Kirinya Julian , Mbaye Samba , Wooldridge Lena , Raile Amber N. W. , Post Lori Ann
Published: February 2018

The international community has advocated the adoption of climate‐smart agriculture (CSA) as lower‐income countries deal with the negative consequences of climate change. Scaling up such policies, practices, and programs successfully will require support from a variety of local stakeholders. Such support requires alignment between CSA solutions and the problem understandings of stakeholders. However, problem understandings can differ across individuals, stakeholder groups, and geographic areas. Consequently, we examine understandings of climate problems and socioeconomic and infrastructure problems related to agriculture among different stakeholder groups in Uganda and Senegal. We operationalized and measured these problem understandings following the detailed guidance of the political will and public will approach for analyzing social change. Semistructured interviews elicited stakeholder‐generated lists of problems for each group. Limited quantification of problem understandings and their relative importance or “ripeness” demonstrates how contexts might shape opportunities for CSA.
The wisdom of the body: Listeners' autonomic arousal distinguishes between spontaneous and posed vocal emotions
Authors: Juslin Patrik N. , Harmat László , Laukka Petri
Published: February 2018

It has been the matter of much debate whether perceivers are able to distinguish spontaneous vocal expressions of emotion from posed vocal expressions (e.g., emotion portrayals). In this experiment, we show that such discrimination can be manifested in the autonomic arousal of listeners during implicit processing of vocal emotions. Participants (N= 21, age: 20–55 years) listened to two consecutive blocks of brief voice clips and judged the gender of the speaker in each clip, while we recorded three measures of sympathetic arousal of the autonomic nervous system (skin conductance level, mean arterial blood pressure, pulse rate). Unbeknownst to the listeners, the blocks consisted of two types of emotional speech: spontaneous and posed clips. As predicted, spontaneous clips yielded higher arousal levels than posed clips, suggesting that listeners implicitly distinguished between the two kinds of expression, even in the absence of any requirement to retrieve emotional information from the voice. We discuss the results with regard to theories of emotional contagion and the use of posed stimuli in studies of emotions.
Glycan distribution and density in native skin's stratum corneum
Authors: Danzberger J. , Donovan M. , Rankl C. , Zhu R. , Vicic S. , Baltenneck C. , Enea R. , Hinterdorfer P. , Luengo G. S.
Published: February 2018

Background

The glycosylation of proteins on the surface of corneocytes is believed to play an important role in cellular adhesion in the stratum corneum (SC) of human skin. Mapping with accuracy the localization of glycans on the surface of corneocytes through traditional methods of immunohistochemistry and electron microscopy remains a challenging task as both approaches lack enough resolution or need to be performed in high vacuum conditions.

Materials and methods

We used an advanced mode of atomic force microscope (AFM), with simultaneous topography and recognition imaging to investigate the distribution of glycans on native (no chemical preparation) stripped samples of human SC. The AFM cantilever tips were functionalized with anti‐heparan sulfate antibody and the lectin wheat germ agglutinin (WGA) which binds specifically to N‐acetyl glucosamine and sialic acid.

Results

From the recognition imaging, we observed the presence of the sulfated glycosaminoglycan, heparan sulfate, and the glycans recognized by WGA on the surface of SC corneocytes in their native state. These glycans were found associated with bead‐like domains which represent corneodesmosomes in the SC layers. Glycan density was calculated to be ~1200 molecules/μm2 in lower layers of SC compared to an important decrease, (~106 molecules/μm2) closer to the surface due probably to corneodesmosome degradation.

Conclusion

Glycan spatial distribution and degradation is first observed on the surface of SC in native conditions and at high resolution. The method used can be extended to precisely localize the presence of other macromolecules on the surface of skin or other tissues where the maintenance of its native state is required.
Headwinds, Tailwinds, and Preferences for Income Redistribution
Authors: Chavanne David
Published: February 2018

Objective

This study examines how preferences for income redistribution respond to information that points to the degree to which bad luck causes poverty and good luck causes wealth.

Methods

Survey respondents saw a vignette that described why someone is poor or a vignette that described why someone is wealthy; poverty and wealth were products of effort, various mixtures of effort and luck, one dimension of luck, or two dimensions of luck.

Results

Overall trends in the data show that redistribution is viewed more favorably as luck becomes marginally more important in causing both poverty and wealth. Pairwise comparisons of specific treatments show that responses to how degrees of bad luck cause poverty are more uniform and predictable than responses to how degrees of good luck cause wealth.

Conclusion

Redistributive preferences may be more malleable with respect to information that points to how bad luck contributes to poverty.
Stabilization and translation of synthetic operon‐derived mRNAs in chloroplasts by sequences representing PPR protein‐binding sites
Authors: Legen Julia , Ruf Stephanie , Kroop Xenia , Wang Gongwei , Barkan Alice , Bock Ralph , Schmitz‐Linneweber Christian
Published: February 2018

The chloroplast is a prime target for genetic engineering in plants, offering various advantages over nuclear transformation. For example, chloroplasts allow the expression of polycistronic transcripts and thus to engineer complex metabolic pathways. Each cistron within such a longer transcript needs its own expression elements. Within the 5′‐UTR, such expression elements are needed for stabilizing mRNAs and for translation of the downstream reading frame. One of the few effective expression elements used so far in transplastomic approaches is the intercistronic expression element (IEE). The IEE is derived from the psbT‐psbH intergenic region and includes a target sequence of the RNA binding protein HCF107. We here show that excessive expression of the IEE can lead to specific defects of endogenous chloroplast mRNA stabilization, likely via depletion of HCF107. Key players in chloroplast transcript stabilization and translation are pentatricopeptide repeat (PPR) proteins, which are structurally related to HCF107. PPR proteins that stabilize mRNAs leave behind short RNA footprints that are indicators of their activity. We identified such sRNAs in tobacco, and demonstrate that they are sufficient to stabilize and stimulate translation of mRNAs from synthetic dicistronic transgenes in chloroplasts. Thus, minimal sequence elements are generally adequate to support key steps in chloroplast gene expression, i.e. RNA stability and translation. Furthermore, our analysis expands the repertoire of available expression elements to facilitate the assembly and expression of multi‐gene ensembles in the chloroplast.
Multifaceted regenerative lives of ‘expired’ platelets
Authors: Burnouf T.
Published: February 2018

There is great interest in using expired platelet concentrates for producing human platelet lysates (hPLs) for cell therapy procedures and, potentially, regenerative medicine. The scientific rationale lies in the richness of platelets in growth factors and cytokines and other cell growth‐promoting biomolecules. The main use of hPL is to replace fetal bovine serum (FBS) for cell therapy protocols for clinical‐grade xeno‐free nutritional supplementation of propagation media. To improve consistency, hPLs may be currently manufactured by pooling the lysates from approximately 16 to 50 frozen platelet concentrates, depending upon jurisdiction. hPL is used as growth medium supplement to expand primary mesenchymal stromal cells (MSCs) from different tissues, as well as various differentiated primary cells. hPLs avoid immunological and zoonotic infectious risks linked to FBS, exhibit potent capacity at expanding cells, shortening the cell population doubling time while maintaining cell physiological, biochemical and functional properties, and, for MSCs, capacity to differentiate. Nonexpired autologous or allogeneic platelet‐derived biomaterials are used in regenerative medicine to enhance the healing and repair of damaged or injured tissues. However, the variability in these products does not generally allow to draw evidence‐based conclusions, and recommendations on best clinical practices remain needed. Future trends may include the development of large‐scale virally inactivated hPLs manufactured following controlled conditions meeting specifications tailored‐made for dedicated clinical applications. In conclusion, there is a scientific rationale for making optimal use of expired platelets to produce standardized growth factor preparations for both cell therapy procedures and dedicated regenerative medicine applications.
Graphene oxide nanosheets modified with trithiocyanuric acid for extraction and enrichment of Pb (II) and Cu (II) ions in seawater
Authors: Mosavi Seyedeh Sara , Ghanemi Kamal , Nickpour Yadollah
Published: February 2018

Trithiocyanuric acid (TTC) is a robust chelating ligand for extracting divalent and univalent heavy metals from water samples. In this method, graphene oxide nanosheets (GO) was modified with TTC, to produce a new nano‐adsorbent (GO‐TTC), for extraction and preconcentration of Pb (II) and Cu (II) ions from seawater samples. The concentrated analytes were measured by a flame atomic absorption spectrometry. The detection limits of the method for Pb (II) and Cu (II) ions were 0.32 ng/mL and 0.13 ng/mL, respectively. The relative standard deviations of analytes for six successive extractions were below 1.64%. The maximum adsorption capacity of GO‐TTC for Pb (II) and Cu (II) ions was 750 µg/g and 460 µg/g, respectively. The recoveries of the spiked analytes in artificial and natural seawater samples were above 90%, pointing out that the method is not affected by the major coexisting ions in seawater matrices.
Reliability, validity and relevance of needs assessment instruments for informal dementia caregivers: a psychometric systematic review protocol
Authors: Kipfer Stephanie , Eicher Manuela , Oulevey Bachmann Annie , Pihet Sandrine
Published: February 2018

Review question/objective:

The objective of this psychometric review is to identify needs assessment instruments for informal dementia caregivers which are:

i. Reliable and valid in measuring the needs of informal dementia caregivers

ii. Relevant for clinical practice, research and informal caregivers

More specifically, the aim is to present an overview and an evaluation of the available needs assessment instruments, including: i) their psychometrics (reliability and validity) when available, and ii) their relevance according to the instrument characteristics, namely, their purpose, application method, administration burden, number of items and domain structure.
Effectiveness of interventions to prevent medication errors: an umbrella systematic review protocol
Authors: Hines Sonia , Kynoch Kathryn , Khalil Hanan
Published: February 2018

Review question:

What is the effectiveness of interventions designed to prevent medication error on medication administration errors, medication-related harms and medication-related death in acute care patients?
Second trimester ultrasound detection of fetal anomalies in the obese obstetrical population: a systematic review protocol
Authors: Preen Christina , Munn Zachary , Raju Smita , Flack Nicholas
Published: February 2018

Review question/objective:

The objective of this review is to identify, appraise and synthesize the best available evidence on the impact of maternal obesity on mid second trimester ultrasound detection of fetal anomalies in pregnancy.
Prediction of the Effect of Impeller Trimming on the Hydraulic Performance of Low Specific-Speed Centrifugal Pumps
Authors: Detert Oude Weme D. G. J. , van der Schoot M. S. , Kruyt N. P. , van der Zijden E. J. J.
Published: February 2018

The effect of trimming of radial impellers on the hydraulic performance of low specific-speed centrifugal pumps is studied. Prediction methods from literature, together with a new prediction method that is based on the simplified description of the flow field in the impeller, are used to quantify the effect of trimming on the hydraulic performance. The predictions by these methods are compared to measured effects of trimming on the hydraulic performance for an extensive set of pumps for flow rates in the range of 80% to 110% of the best efficiency point. Of the considered methods, the new prediction method is more accurate (even for a large impeller trim of 12%) than the considered methods from literature. The new method generally overestimates the reduction in the pump head after trimming, and hence results less often in impeller trims that are too large when the method is used to determine the amount of trimming that is necessary in order to attain a specified head.
Structural Dynamics Analysis of Three-Dimensional Bi-Axial Sun-Tracking System Structure Determined by Numerical Modal Analysis
Authors: Ferroudji Fateh , Khelifi Cherif , Outtas Toufik
Published: February 2018

Sun-tracking system (STS) is a key factor for solar photovoltaic (PV) future and new answers for the solar market. It will expand large-scale PV projects (PV farms) worldwide, and it is possible to collect more energy from the sun. PV farms consist of thousands of STS that are subject to dynamic loads (wind, snow, etc.), vibrations, and gravitational loads. This paper presents the structural dynamic analysis of a 24 m2 bi-axial STS (azimuth-elevation) at different elevation angles based on its modal parameters (natural frequencies, modal shapes, and modal damping ratios) and dynamic performance indices (modal participation factors (MPF), forcing frequencies, and mechanical quality factors) by means of the finite element analysis (FEA). The simulation results show that the structural dynamic design of the STS meets the desired structural requirements and agrees well with structural dynamic standards (EN 1991-1-4 and ASHRAE). These results can be used for further analysis on optimal design and vibration safety verification for the bi-axial STS (PV applications).
Numerical Analysis on Thermal Energy Storage Device With Finned Copper Tube for an Indirect Type Solar Drying System
Authors: Yadav Satyapal , Chandramohan V. P.
Published: February 2018

Solar dryer with thermal energy storage device is an essential topic for food drying applications in industries. In this work, a two-dimensional (2D) numerical model is developed for the application of solar drying of agricultural products in an indirect type solar dryer. The phase-change material (PCM) used in this work is paraffin wax. The study has been performed on a single set of concentric tube which consists of a finned inner copper tube for air flow and an outer plastic tube for PCM material. The practical domain is modeled using ANSYS, and computer simulations were performed using ANSYS fluent 2015. The air velocity and temperature chosen for this study are based on the observation of indirect type solar dryer experimental setup. From this numerical analysis, the temperature distribution, melting, and solidification fraction of PCM are estimated at different air flow velocities, time, and inlet temperature of air. It is concluded that the drying operation can be performed up to 10.00 p.m. as the PCM transfers heat to inlet air up to 10.00 p.m. and before it got charged up to 3.00 p.m. because of solar radiation. The maximum outlet temperature is 341.62 K (68.62 °C) which is suitable for food drying applications. Higher air flow velocity enhances quick melting of PCM during charging time and quick cooling during recharging of inlet air; therefore, higher air flow velocity is not preferred for food drying during cooling of PCM.
Online Policy Iteration-Based Tracking Control of Four Wheeled Omni-Directional Robots
Authors: Sheikhlar Arash , Fakharian Ahmad
Published: February 2018

In this paper, online policy iteration reinforcement learning (RL) algorithm is proposed for motion control of four wheeled omni-directional robots. The algorithm solves the linear quadratic tracking (LQT) problem in an online manner using real-time measurement data of the robot. This property enables the tracking controller to compensate the alterations of dynamics of the robot's model and environment. The online policy iteration based tracking method is employed as low level controller. On the other side, a proportional derivative (PD) scheme is performed as supervisory planning system (high level controller). In this study, the followed paths of online and offline policy iteration algorithms are compared in a rectangular trajectory in the presence of slippage drawback and motor heat. Simulation and implementation results of the methods demonstrate the effectiveness of the online algorithm compared to offline one in reducing the command trajectory tracking error and robot's path deviations. Besides, the proposed online controller shows a considerable ability in learning appropriate control policy on different types of surfaces. The novelty of this paper is proposition of a simple-structure learning based adaptive optimal scheme that tracks the desired path, optimizes the energy consumption, and solves the uncertainty problem in omni-directional wheeled robots.
Seasonal variation of a population Unionicola penicillatus (Unionicolidae) from the freshwater bivalve Cristaria plicata (Unionidae) in Poyang Lake, eastern China
Authors: Zhang Fei , Cheng Jian , Wen Chungen , Hu Baoqing , Yang Gang , Jian Shaoqing
Published: February 2018

The water mite Unionicola penicillatus (Wen, Gao & Zhu) (Acari: Unionicolidae) was collected in freshwater bivalve Cristaria plicata (Unionidae). The population variation of U. penicillatus was investigated in 504 bivalves during the period from August 2013 to July 2014 in Poyang Lake, East China. The results indicated that the overall prevalence and abundance of U. penicillatus was 9.52% and 1.58±10.38. The highest prevalence was 58.70% in September. The highest abundance levels were observed when the length of bivalves was in 220–300 mm. The number of U. penicillatus in a host was not correlated with the sex of bivalves. The outer and inner gills of bivalves were the preferred sites of U. penicillatus.
Increasing Inequality in Physical Activity Among Minnesota Secondary Schools, 2001–2010
Authors: Nelson Toben F. , MacLehose Richard F. , Davey Cynthia , Rode Peter , Nanney Marilyn S.
Published: February 2018

Background: Two Healthy People 2020 goals are to increase physical activity (PA) and to reduce disparities in PA. We explored whether PA at the school level changed over time in Minnesota schools and whether differences existed by demographic and socioeconomic factors. Methods: We examine self-reported PA (n = 276,089 students; N = 276 schools) for 2001–2010 from the Minnesota Student Survey linked to school demographic data from the National Center for Education Statistics and the Rural–Urban Commuting Area Codes. We conducted analyses at the school level using multivariable linear regression with cluster-robust recommendation errors. Results: Overall, students who met PA recommendations increased from 59.8% in 2001 to 66.3% in 2010 (P < .001). Large gains in PA occurred at schools with fewer racial/ethnic minority students (0%–60.1% in 2001 to 67.5% in 2010, P < .001), whereas gains in PA were comparatively small at schools with a high proportion of racial/ethnic minority students in 2001 (30%–59.2% in 2001 to 62.7% in 2010). Conclusions: We found increasing inequalities in school-level PA by racial/ethnic characteristics of their schools and communities among secondary school students. Future research should monitor patterns of PA over time and explore mechanisms for patterns of inequality.
Brain Dynamics and Motor Behavior: A Case for Efficiency and Refinement for Superior Performance
Authors: Hatfield Bradley D.
Published: February 2018

The paper presents a theoretical perspective on brain activity that characterizes expert cognitive-motor performance grounded in neural and psychomotor efficiency. Evidence for the position is derived from several different measurement tools (EEG, ERPs, fMRI, EEG coherence) based on empirical studies of (1) expert-novice contrasts, (2) changes in the brain after practice, and (3) motor performance under conditions of mental stress. The impact of mental stress on brain processes during motor performance is then discussed followed by a model of the hypothesized central neural responses to emotion-eliciting events to explain resilience to stress and the ability to “perform under pressure” as observed in high-performing athletes. An overall explanation is offered of the cascade of events that link the perception of the environment in which the performance occurs to the peripheral process of motor unit recruitment and the resultant quality of movement. This integrative perspective on human performance considers multiple levels of explanation including the psychology of sport performance, cognitive-motor neuroscience, and basic biomechanics to understand the kinematic qualities of movement and the effort cost involved.
Grking the Smoothened signal
Authors: Sharpe Hayley J. , de Sauvage Frederic J.
Published: February 2018

The essential Hedgehog signaling component GRK2 functions at the level of and downstream of Smoothened in both flies and vertebrates (Li
et al
. and Pusapati
et al
., in 6 February 2018 issue).
Anidulafungin Pharmacokinetics in Ascites Fluid and Pleural Effusion of Critically Ill Patients
Authors: Welte R. , Eller P. , Lorenz I. , Joannidis M. , Bellmann R.
Published: February 2018

Anidulafungin concentrations were quantified with high-pressure liquid chromatography (HPLC) and UV detection of the ascites fluid and pleural effusion of 10 adult critically ill patients. Samples were collected from ascites fluid and from pleural drains or during paracentesis and thoracentesis, respectively. Anidulafungin levels in ascites fluid (0.12 to 0.99 μg/ml) and in pleural effusion (0.32 to 2.02 μg/ml) were below the simultaneous levels in plasma (1.04 to 7.70 and 2.48 to 13.36 μg/ml, respectively) and below the MIC values for several pathogenic
Candida
strains.
Next-Generation Sequencing and Bioinformatics Protocol for Malaria Drug Resistance Marker Surveillance
Authors: Talundzic Eldin , Ravishankar Shashidhar , Kelley Julia , Patel Dhruviben , Plucinski Mateusz , Schmedes Sarah , Ljolje Dragan , Clemons Brooke , Madison-Antenucci Susan , Arguin Paul M. , Lucchi Naomi W. , Vannberg Fredrik , Udhayakumar Venkatachalam
Published: February 2018

The recent advances in next-generation sequencing technologies provide a new and effective way of tracking malaria drug-resistant parasites. To take advantage of this technology, an end-to-end Illumina targeted amplicon deep sequencing (TADS) and bioinformatics pipeline for molecular surveillance of drug resistance in
P. falciparum
, called
ma
laria
r
esistance
s
urveillance (MaRS), was developed. TADS relies on PCR enriching genomic regions, specifically target genes of interest, prior to deep sequencing. MaRS enables researchers to simultaneously collect data on allele frequencies of multiple full-length
P. falciparum
drug resistance genes (
crt
,
mdr1
,
k13
,
dhfr
,
dhps
, and the cytochrome
b
gene), as well as the mitochondrial genome. Information is captured at the individual patient level for both known and potential new single nucleotide polymorphisms associated with drug resistance. The MaRS pipeline was validated using 245 imported malaria cases that were reported to the Centers for Disease Control and Prevention (CDC). The chloroquine resistance
crt
CV
IET
genotype (mutations underlined) was observed in 42% of samples, the highly pyrimethamine-resistant
dhps
IRN
triple mutant in 92% of samples, and the sulfadoxine resistance
dhps
mutation S
GE
AA in 26% of samples. The
mdr1
N
F
SND genotype was found in 40% of samples. With the exception of two cases imported from Cambodia, no artemisinin resistance
k13
alleles were identified, and 99% of patients carried parasites susceptible to atovaquone-proguanil. Our goal is to implement MaRS at the CDC for routine surveillance of imported malaria cases in the United States and to aid in the adoption of this system at participating state public health laboratories, as well as by global partners.
Draft Genome Sequence of
Endozoicomonas acroporae
Strain Acr-14
T
, Isolated from
Acropora
Coral
Authors: Tandon Kshitij , Chiang Pei-Wen , Chen Wen-Ming , Tang Sen-Lin
Published: February 2018

A lacuna exists in our understanding of the genetic makeup of
Endozoicomonas
bacteria, due to scarcity of genome sequences. We report here the first draft genome sequence of 
Endozoicomonas acroporae
 Acr-14, a type strain isolated from the coral
Acropora
. This sequence will foster an understanding of the genetic makeup and role of hosts in shaping gene repertoires.
Complete Genome Sequence of Industrial Dairy Strain
Streptococcus thermophilus
DGCC 7710
Authors: Hatmaker E. Anne , Riley Lauren A. , O’Dell Kaela B. , Papanek Beth , Graveley Brenton R. , Garrett Sandra C. , Wei Yunzhou , Terns Michael P. , Guss Adam M.
Published: February 2018

We report here the complete genome sequence of
Streptococcus thermophilus
DGCC 7710.
S. thermophilus
is widely used in industrial dairy production.
Autoregulation and Virulence Control by the Toxin-Antitoxin System SavRS in Staphylococcus aureus
Authors: Wen Wen , Liu Banghui , Xue Lu , Zhu Zhongliang , Niu Liwen , Sun Baolin
Published: February 2018

Toxin-antitoxin (TA) systems play diverse physiological roles, such as plasmid maintenance, growth control, and persister cell formation, but their involvement in bacterial pathogenicity remains largely unknown. Here, we have identified a novel type II toxin-antitoxin system, SavRS, and revealed the molecular mechanisms of its autoregulation and virulence control in
Staphylococcus aureus
. Electrophoretic mobility shift assay and isothermal titration calorimetry data indicated that the antitoxin SavR acted as the primary repressor bound to its own promoter, while the toxin SavS formed a complex with SavR to enhance the ability to bind to the operator site. DNase I footprinting assay identified the SavRS-binding site containing a short and long palindrome in the promoter region. Further, mutation and DNase I footprinting assay demonstrated that the two palindromes were crucial for DNA binding and transcriptional repression. More interestingly, genetic deletion of the
savRS
system led to the increased hemolytic activity and pathogenicity in a mouse subcutaneous abscess model. We further identified two virulence genes,
hla
and
efb
, by real-time quantitative reverse transcription-PCR and demonstrated that SavR and SavRS could directly bind to their promoter regions to repress virulence gene expression.
Evaluation of a Commercial Multiplex Molecular Panel for Diagnosis of Infectious Meningitis and Encephalitis
Authors: Liesman Rachael M. , Strasburg Angela P. , Heitman Angela K. , Theel Elitza S. , Patel Robin , Binnicker Matthew J.
Published: February 2018

Rapid and accurate laboratory tests are important for the timely diagnosis and treatment of central nervous system infections. The FilmArray meningitis/encephalitis (ME) panel (BioFire Diagnostics, Salt Lake City, UT) is an FDA-cleared, multiplex molecular panel that allows the detection of 14 pathogens (bacterial [
n
= 6], viral [
n
= 7], and fungal [
n
= 1] pathogens) from cerebrospinal fluid (CSF). In this study, we evaluated the performance characteristics of the FilmArray ME panel using clinical, residual CSF samples (
n
= 291) that tested positive by a routine method(s) (e.g., bacterial culture, individual real-time PCR assay) for a pathogen represented on the ME panel. Of note, a subset (
n
= 76) of the CSF specimens was collected during the prevaccine era and had been characterized as positive for a bacterial pathogen. The FilmArray ME panel demonstrated an overall percent positive agreement (PPA) of 97.5% (78/80) for bacterial pathogens, 90.1% (145/161) for viruses, and 52% (26/50) for
Cryptococcus
neoformans/C. gattii
. Despite the low overall agreement (52%) between the ME panel and antigen testing for detection of
C. neoformans/C. gattii
, the percent positive agreement of the FilmArray assay for
C. neoformans/C. gattii
was 92.3% (12/13) when the results were compared directly to the results of routine fungal smear or culture. The FilmArray ME panel offers a rapid (∼60-min), syndrome-based approach for the detection of select meningitis and encephalitis pathogens.