bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crosstalk between Agrin and Wnt signaling pathways in development of vertebrate neuromuscular junction
Authors: Barik Arnab , Zhang Bin , Sohal Gurkirpal S. , Xiong Wen‐Cheng , Mei Lin 
Published: May 2014

ABSTRACTNeuromuscular junction (NMJ) is a cholinergic synapse where motor neurons elicit muscle contraction. Agrin and its coreceptors LRP4 and MuSK are critical for vertebrate NMJ formation. This paper reviews recent evidence for Wnts and Wnt signaling molecules in NMJ formation including a possible retrograde mechanism by muscle β‐catenin. We also present data that Wnt3a, 7a, 8a and 10b could inhibit agrin‐mediated AChR clustering. Together with the stimulating effect of Wnt9a, 9b, 10b, 11 and 16 on AChR clustering in the absence of agrin, these results suggest diverse roles for Wnt ligands in NMJ development. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 74: 828–838, 2014
Developmental wave of Brn3b expression leading to RGC fate specification is synergistically maintained by miR‐23a and miR‐374
Authors: Rasheed Vazhanthodi A. , Sreekanth Sreekumaran , Dhanesh Sivadasan B. , Divya Mundackal S. , Divya Thulasi S. , Akhila Palakkottu K. , Subashini Chandramohan , Chandrika Sivakumar Krishnankutty , Das Ani V. , James Jackson 
Published: May 2014

ABSTRACTDifferential regulation of Brn3b is essential for the Retinal Ganglion Cell (RGC) development in the two phases of retinal histogenesis. This biphasic Brn3b regulation is required first, during early retinal histogenesis for RGC fate specification and secondly, during late histogenesis, where Brn3b is needed for RGC axon guidance and survival. Here, we have looked into how the regulation of Brn3b at these two stages happens. We identified two miRNAs, miR‐23a and miR‐374, as regulators of Brn3b expression, during the early stage of RGC development. Temporal expression pattern of miR‐23a during E10–19, PN1–7, and adult retina revealed an inverse relation with Brn3b expression. Though miR‐374 did not show such a pattern, its co‐expression with miR‐23a evidently inhibited Brn3b. We further substantiated these findings by ex vivo overexpression of these miRNAs in E14 mice retina and found that miR‐23a and miR‐374 together brings about a change in Brn3b expression pattern in ganglion cell layer (GCL) of the developing retina. From our results, it appears that the combined expression of these miRNAs could be regulating the timing of the wave of Brn3b expression required for early ganglion cell fate specification and later for its survival and maturation into RGCs. Taken together, here we provide convincing evidences for the existence of a co‐ordinated mechanism by miRNAs to down regulate Brn3b that will ultimately regulate the development of RGCs from their precursors. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 74: 1155–1171, 2014
Abiotic stress QTL in lettuce crop–wild hybrids: comparing greenhouse and field experiments
Authors: Hartman Yorike , Hooftman Danny A. P. , Uwimana Brigitte , Schranz M. Eric , van de Wiel Clemens C. M. , Smulders Marinus J. M. , Visser Richard G. F. , Michelmore Richard W. , van Tienderen Peter H. 
Published: May 2014

AbstractThe development of stress‐tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected recombinant inbred lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and aboveground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and colocated with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated with those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans‐)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses, especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives.
Maximizing species conservation in continentalEcuador: a case of systematic conservation planning for biodiverse regions
Authors: Lessmann Janeth , Muñoz Jesús , Bonaccorso Elisa 
Published: May 2014

AbstractEcuador has the largest number of species by area worldwide, but also a low representation of species within its protected areas. Here, we applied systematic conservation planning to identify potential areas for conservation in continental Ecuador, with the aim of increasing the representation of terrestrial species diversity in the protected area network. We selected 809 terrestrial species (amphibians, birds, mammals, and plants), for which distributions were estimated via species distribution models (SDMs), using Maxent. For each species we established conservation goals based on conservation priorities, and estimated new potential protected areas using Marxan conservation planning software. For each selected area, we determined their conservation priority and feasibility of establishment, two important aspects in the decision‐making processes. We found that according to our conservation goals, the current protected area network contains large conservation gaps. Potential areas for conservation almost double the surface area of currently protected areas. Most of the newly proposed areas are located in the Coast, a region with large conservation gaps and irreversible changes in land use. The most feasible areas for conservation were found in the Amazon and Andes regions, which encompass more undisturbed habitats, and already harbor most of the current reserves. Our study allows defining a viable strategy for preserving Ecuador's biodiversity, by combining SDMs, GIS‐based decision‐support software, and priority and feasibility assessments of the selected areas. This approach is useful for complementing protected area networks in countries with great biodiversity, insufficient biological information, and limited resources for conservation.
Orphan chemoattractant receptor GPR15 mediates dendritic epidermal T‐cell recruitment to the skin
Authors: Lahl Katharina , Sweere Johanna , Pan Junliang , Butcher Eugene 
Published: May 2014

Homing of murine dendritic epidermal T cells (DETCs) from the thymus to the skin is regulated by specific trafficking receptors during late embryogenesis. Once in the epidermis, Vγ3δ1 TCR DETCs are maintained through self‐renewal and participate in wound healing. GPR15 is an orphan G protein‐linked chemoattractant receptor involved in the recruitment of regulatory T cells to the colon. Here we show that GPR15 is highly expressed on fetal thymic DETC precursors and on recently recruited DETCs, and mediates the earliest seeding of the epidermis, which occurs at the time of establishment of skin barrier function. DETCs in GPR15−/− mice remain low at birth, but later participation of CCR10 and CCR4 in DETC homing allows DETCs to reach near normal levels in adult skin. Our findings establish a role for GPR15 in skin lymphocyte homing and suggest that it may contribute to lymphocyte subset targeting to diverse epithelial sites.
Modeling oxyanion adsorption on ferralic soil, part 1: Parameter validation with phosphate ion
Authors: Pérez Claudio , Antelo Juan , Fiol Sarah , Arce Florencio 
Published: May 2014

Abstract

Surface complexation models have proved to be valuable tools for predicting processes that occur at the solid–solution interface. Use of such models has become more widespread and nowadays more complex systems are studied, in an attempt to explain processes such as the competition between different species for mineral surfaces and the effect of the presence of organic matter. The aim of the present study was to analyze the mobility of phosphate in ferralic soils. The charge distribution model parameters for phosphate–goethite adsorption were used to predict phosphate mobility on samples from 2 horizons of a ferralic soil containing large amounts of iron oxides. The soil reactivity was attributed to the iron oxides, and some specific parameters were determined by means of phosphate adsorption–desorption experiments and included in the model. Adsorption of phosphate in the upper horizon, which contained more organic carbon and phosphate than the deeper one, was modeled by using the information obtained for the soil and the charge distribution model parameters derived for phosphate–goethite interaction with no need of further optimization. In contrast, some extra fitting parameters were required to improve the modeling of the phosphate adsorption in the deeper horizon. Environ Toxicol Chem 2014;33:2208–2216. © 2014 SETAC
Growth, oxidative stress responses, and gene transcription of juvenile bighead carp (Hypophthalmichthys nobilis) under chronic-term exposure of ammonia
Authors: Sun Hongjie , Wang Wenqian , Li Jiajia , Yang Zhou 
Published: May 2014

Abstract

Ammonia toxicity has become a universal problem for aquatic animals, especially fish. The purpose of the present study was to assess the chronic toxicity of ammonia to the juvenile bighead carp (Hypophthalmichthys nobilis). The authors measured the responses of growth performance (specific growth rate, condition factor, body weight, and body length), oxidative stress, and related gene transcription of juvenile bighead carp exposed to solutions with different concentrations of un-ionized ammonia (UIA; 0 mg L−1, 0.053 mg L−1, 0.106 mg L−1, 0.159 mg L−1, and 0.212 mg L−1). The results showed that UIA had no effect on growth performance, glutathione content, or glutathione S-transferase gene transcription, but superoxide dismutase (SOD) activity was significantly elevated. In addition, different concentrations of UIA produced different degrees of damage to juvenile bighead carp: compared with control, lower UIA levels significantly decreased gene transcription of catalase (CAT) and increased malondialdehyde (MDA) levels; higher UIA concentration (0.212 mg L−1) significantly increased gene transcription of the antioxidant enzymes CAT and SOD and reduced MDA levels. The data clearly demonstrate that chronic exposure of UIA at lower concentrations can result in some degree of impairment of antioxidative function, and chronic exposure at higher concentrations can enhance damage to juvenile bighead carp by modulating antioxidant enzyme activities and gene transcription. Environ Toxicol Chem 2014;33:1726–1731. © 2014 SETAC
Reducing aquatic hazards of industrial chemicals: Probabilistic assessment of sustainable molecular design guidelines
Authors: Connors Kristin A. , Voutchkova-Kostal Adelina M. , Kostal Jakub , Anastas Paul , Zimmerman Julie B. , Brooks Bryan W. 
Published: May 2014

Abstract

Basic toxicological information is lacking for the majority of industrial chemicals. In addition to increasing empirical toxicity data through additional testing, prospective computational approaches to drug development aim to serve as a rational basis for the design of chemicals with reduced toxicity. Recent work has resulted in the derivation of a “rule of 2,” wherein chemicals with an octanol–water partition coefficient (log P) less than 2 and a difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital (ΔE) greater than 9 (log P &lt; 2 and ΔE &gt; 9 eV) are predicted to be 4 to 5 times less likely to elicit acute or chronic toxicity to model aquatic organisms. The present study examines potential reduction of aquatic toxicity hazards from industrial chemicals if these 2 molecular design guidelines were employed. Probabilistic hazard assessment approaches were used to model the likelihood of encountering industrial chemicals exceeding toxicological categories of concern both with and without the rule of 2. Modeling predicted that utilization of these molecular design guidelines for log P and ΔE would appreciably decrease the number of chemicals that would be designated to be of “high” and “very high” concern for acute and chronic toxicity to standard model aquatic organisms and end points as defined by the US Environmental Protection Agency. For example, 14.5% of chemicals were categorized as having high and very high acute toxicity to the fathead minnow model, whereas only 3.3% of chemicals conforming to the design guidelines were predicted to be in these categories. Considerations of specific chemical classes (e.g., aldehydes), chemical attributes (e.g., ionization), and adverse outcome pathways in representative species (e.g., receptor-mediated responses) could be used to derive future property guidelines for broader classes of contaminants. Environ Toxicol Chem 2014;33:1894–1902. © 2014 SETAC
Toxicity of different-sized copper nano- and submicron particles and their shed copper ions to zebrafish embryos
Authors: Hua Jing , Vijver Martina G. , Ahmad Farooq , Richardson Michael K. , Peijnenburg Willie J.G.M. 
Published: May 2014

Abstract

Three sizes of copper nanoparticles (Cu NPs; 25 nm, 50 nm, and 100 nm), 1 submicron-sized particle, and Cu(NO3)2 were added to the culture buffer of zebrafish embryos from 24 h postfertilization to 120 h postfertilization. In suspensions of Cu NPs and the Cu submicron-sized particle, the main contribution to the toxicity to zebrafish embryos was from the particle form of Cu particles (Cu NPparticle, &gt;71%) rather than from dissolved Cu from the Cu particles (Cu NPion). All particles tested as well as copper nitrate inhibited hatching, altered behavioral responses, and increased the incidence of malformations. Different kinds of abnormalities were observed in the morphology and behavior of the zebrafish embryos, depending on the particle size of the Cu suspensions tested. The median lethal concentrations of Cu NPparticle (25 nm, 50 nm, and 100 nm), the submicron-sized particle, and copper nitrate were 0.58 mg/L, 1.65 mg/L, 1.90 mg/L, 0.35 mg/L, and 0.70 mg/L, respectively. Submicron-sized particles and copper nitrate were more toxic than Cu NPs, and smaller Cu NPs were more toxic than larger Cu NPs. Dissolution of Cu NPs and the subsequent ion toxicity was not the primary mechanism of Cu NP toxicity in zebrafish embryos. Environ Toxicol Chem 2014;33:1774–1782. © 2014 SETAC
Hydrologic changes resulting from urban cover in seasonally snow‐covered catchments
Authors: Eimers M. Catherine , McDonald Ethan C. 
Published: May 2014

AbstractThere are few multibasin analyses of the effects of urban land cover on seasonal stream flow patterns within northern watersheds where winter snow cover is the norm. In this study, the effects of urban cover on stream flow were evaluated at nine catchments in southern Ontario, Canada, which vary greatly in urban impervious cover (1–84%) but cluster into two groups having ≥54% urban impervious area (‘urban’) and ≤11% impervious cover (‘rural’), respectively. Annual and seasonal run‐off totals (millimetres) were similar between the rural and urban groups and were relatively insensitive to urban cover. Instead, urban streams had significantly greater high flow frequency, flow variability and quickflow and lower baseflow compared with rural streams. Furthermore, differences in high flow frequency between urban and rural stream groups were largest in the summer and fall and less extreme in the winter and spring, perhaps because of the homogenizing effect of winter snow cover, frozen ground and spring melt on surface imperviousness. Although the clear clustering of streams into urban and rural groups precluded the identification of a threshold above which urban cover is the primary cause of flow differences, relatively high extreme flow frequency and flow variability in the two most urbanized of the rural streams (10–11% impervious) suggest that it may lie close to this range. Furthermore, whereas total run‐off volumes were not affected by urban cover, increases in stream flashiness and a greater frequency of high flow events particularly during the summer and fall may negatively impact stream biota and favour the transfer of surface‐deposited pollutants to urban streams. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of cyanobacterial microcystin synthetase (mcy) E gene transcript levels, mcy E gene copies, and biomass as indicators of microcystin risk under laboratory and field conditions
Authors: Ngwa Felexce F. , Madramootoo Chandra A. , Jabaji Suha 
Published: May 2014

AbstractIncreased incidences of mixed assemblages of microcystin‐producing and nonproducing cyanobacterial strains in freshwater bodies necessitate development of reliable proxies for cyanotoxin risk assessment. Detection of microcystin biosynthetic genes in water blooms of cyanobacteria is generally indicative of the presence of potentially toxic cyanobacterial strains. Although much effort has been devoted toward elucidating the microcystin biosynthesis mechanisms in many cyanobacteria genera, little is known about the impacts of co‐occurring cyanobacteria on cellular growth, mcy gene expression, or mcy gene copy distribution. The present study utilized conventional microscopy, qPCR assays, and enzyme‐linked immunosorbent assay to study how competition between microcystin‐producing Microcystis aeruginosa CPCC 299 and Planktothrix agardhii NIVA‐CYA 126 impacts mcyE gene expression, mcyE gene copies, and microcystin concentration under controlled laboratory conditions. Furthermore, analyses of environmental water samples from the Missisquoi Bay, Quebec, enabled us to determine how the various potential toxigenic cyanobacterial biomass proxies correlated with cellular microcystin concentrations in a freshwater lake. Results from our laboratory study indicated significant downregulation of mcyE gene expression in mixed cultures of M. aeruginosa plus P. agardhii on most sampling days in agreement with depressed growth recorded in the mixed cultures, suggesting that interaction between the two species probably resulted in suppressed growth and mcyE gene expression in the mixed cultures. Furthermore, although mcyE gene copies and McyE transcripts were detected in all laboratory and field samples with measureable microcystin levels, only mcyE gene copies showed significant positive correlations (R2 > 0.7) with microcystin concentrations, while McyE transcript levels did not. These results suggest that mcyE gene copies are better indicators of potential risks from microcystins than McyE transcript levels or conventional biomass proxies, especially in water bodies comprising mixed assemblages of toxic and nontoxic cyanobacteria.
Dystonia and tremor secondary to thalamic infarction successfully treated with thalamotomy of the ventralis intermedius nucleus
Authors: Álvarez Mario , Quintanal Nelson , Díaz Amado , Prince José , García Ivan , Carballo Maylen , Rodríguez Rafael , Maragoto Carlos , Pedroso Ivonne , Macías Raul 
Published: May 2014

ABSTRACTBackgroundFocal thalamic lesions have been associated with a variety of involuntary movements such as tremor, dystonia, and chorea‐ballism.MethodsWe describe a patient with severe hyperkinesias of the right arm secondary to a thalamic infarction in the left postero‐ventral region of the thalamus.ResultsThe dystonia and tremor of the right upper limb were subsequently controlled with another surgical lesion of the ventralis intermedius nucleus of the thalamus.ConclusionThis observation suggests that ablative surgery might be applied to treat a movement disorder induced by the lesion of the same nucleus, which in addition lead to interesting pathophysiological conjectures. © 2014 International Parkinson and Movement Disorder Society
Peptidoglycan recognition protein genes and risk of Parkinson's disease
Authors: Goldman Samuel M. , Kamel Freya , Ross G. Webster , Jewell Sarah A. , Marras Connie , Hoppin Jane A. , Umbach David M. , Bhudhikanok Grace S. , Meng Cheryl , Korell Monica , Comyns Kathleen , Hauser Robert A. , Jankovic Joseph , Factor Stewart A. , Bressman Susan , Lyons Kelly E. , Sandler Dale P. , Langston J. William , Tanner Caroline M. 
Published: May 2014

ABSTRACTIncreased gut permeability, inflammation, and colonic α‐synuclein pathology are present in early Parkinson's disease (PD) and have been proposed to contribute to PD pathogenesis. Peptidoglycan is a structural component of the bacterial cell wall. Peptidoglycan recognition proteins (PGRPs) maintain healthy gut microbial flora by regulating the immune response to both commensal and harmful bacteria. We tested the hypothesis that variants in genes that encode PGRPs are associated with PD risk. Participants in two independent case‐control studies were genotyped for 30 single‐nucleotide polymorphisms (SNPs) in the four PGLYRP genes. Using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for potential confounding variables, we conducted analyses in each study, separately and pooled. One SNP failed the assay, and three had little to no variation. The ORs were similar in both study populations. In pooled analyses, three of seven PGLYRP2 SNPs (rs3813135, rs733731, rs892145), one of five PGLYRP3 SNPs (rs2987763), and six of nine PGLYRP4 SNPs (rs10888557, rs12063091, rs3006440, rs3006448, rs3006458, and rs3014864) were significantly associated with PD risk. Association was strongest for PGLYRP4 5'untranslated region (UTR) SNP rs10888557 (GG reference, CG OR 0.6 [95%CI 0.4‐0.9], CC OR 0.15 [95%CI 0.04‐0.6]; log‐additive P‐trend, 0.0004). Common variants in PGLYRP genes are associated with PD risk in two independent studies. These results require replication, but they are consistent with hypotheses of a causative role for the gut microbiota and gastrointestinal immune response in PD. © 2014 International Parkinson and Movement Disorder Society
An adaptive constraint tightening approach to linear model predictive control based on approximation algorithms for optimization
Authors: Necoara Ion , Ferranti Laura , Keviczky Tamás 
Published: May 2014

SummaryIn this paper, we propose a model predictive control scheme for discrete‐time linear invariant systems based on inexact numerical optimization algorithms. We assume that the solution of the associated quadratic program produced by some numerical algorithm is possibly neither optimal nor feasible, but the algorithm is able to provide estimates on primal suboptimality and primal feasibility violation. By adaptively tightening the complicating constraints, we can ensure the primal feasibility of the approximate solutions generated by the algorithm. We derive a control strategy that has the following properties: the constraints on the states and inputs are satisfied, asymptotic stability of the closed‐loop system is guaranteed, and the number of iterations needed for a desired level of suboptimality can be determined. The proposed method is illustrated using a simulated longitudinal flight control problem. Copyright © 2014 John Wiley & Sons, Ltd.