bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertical and seasonal distribution of picoplankton and functional nitrogen genes in a high‐altitude warm‐monomictic tropical lake
Authors: Pajares Silvia , Merino‐Ibarra Martín , Macek Miroslav , Alcocer Javier 
Published: April 2017

Abstract

The nitrogen (N) cycle is highly dependent on microbial processes. Distribution of these communities is one of the most important factors in the variation of the N cycling in warm‐monomictic lakes. However, the effects of the alternation of water stratification and mixing periods on the ecology of microbial communities involved in these processes are rarely studied in this type of aquatic ecosystem.

We explored vertical and seasonal patterns of picoplankton and the genetic potential for ammonium oxidation (amoA gene for bacteria and archaea), denitrification (nirS and nirK), anammox (hzsA), and DNRA (nrfA) and their relationships with the main limnological variables in Lake Alchichica (Central Mexican Plateau) to provide insight into the distribution and importance of these planktonic communities in warm‐monomictic tropical lakes. Ten depths were sampled during late stratification (November 2015) and mixing (February 2016) periods, covering the epilimnion, metalimnion (oxycline), and hypolimnion layers in the first case.

We showed that temperature and oxygen stratification shaped the distribution of picoplankton and functional N genes in this lake. These communities also varied in relation to nutrient availability and underwent temporal changes throughout the water column. The amoA genes, along with autotrophic picoplankton, were more abundant during the stratification, indicating that nitrification could be potentially more important during this period, mainly at the oxycline layer. Denitrifying genes showed strong variations during the stratification period, with highest gene copy numbers at the oxycline and hypolimnion layers. Anoxic conditions were characterised by a relative increase in the abundance of the nrfA gene with depth, which was positively correlated with NH4+ concentration. On the other hand, the hzsA gene was not detected in any sample.

Our findings highlight the importance of thermal stratification as one of the main factors influencing the genetic potential for N transformations within the water column in warm‐monomictic tropical lakes.
Differences in xylem and leaf hydraulic traits explain differences in drought tolerance among mature Amazon rainforest trees
Authors: Powell Thomas L. , Wheeler James K. , de Oliveira Alex A. R. , da Costa Antonio Carlos Lola , Saleska Scott R. , Meir Patrick , Moorcroft Paul R. 
Published: April 2017

AbstractConsiderable uncertainty surrounds the impacts of anthropogenic climate change on the composition and structure of Amazon forests. Building upon results from two large‐scale ecosystem drought experiments in the eastern Brazilian Amazon that observed increases in mortality rates among some tree species but not others, in this study we investigate the physiological traits underpinning these differential demographic responses. Xylem pressure at 50% conductivity (xylem‐P50), leaf turgor loss point (TLP), cellular osmotic potential (πo), and cellular bulk modulus of elasticity (ε), all traits mechanistically linked to drought tolerance, were measured on upper canopy branches and leaves of mature trees from selected species growing at the two drought experiment sites. Each species was placed a priori into one of four plant functional type (PFT) categories: drought‐tolerant versus drought‐intolerant based on observed mortality rates, and subdivided into early‐ versus late‐successional based on wood density. We tested the hypotheses that the measured traits would be significantly different between the four PFTs and that they would be spatially conserved across the two experimental sites. Xylem‐P50, TLP, and πo, but not ε, occurred at significantly higher water potentials for the drought‐intolerant PFT compared to the drought‐tolerant PFT; however, there were no significant differences between the early‐ and late‐successional PFTs. These results suggest that these three traits are important for determining drought tolerance, and are largely independent of wood density—a trait commonly associated with successional status. Differences in these physiological traits that occurred between the drought‐tolerant and drought‐intolerant PFTs were conserved between the two research sites, even though they had different soil types and dry‐season lengths. This more detailed understanding of how xylem and leaf hydraulic traits vary between co‐occuring drought‐tolerant and drought‐intolerant tropical tree species promises to facilitate a much‐needed improvement in the representation of plant hydraulics within terrestrial ecosystem and biosphere models, which will enhance our ability to make robust predictions of how future changes in climate will affect tropical forests.
Survival comparisons of intensive vs. conventional hemodialysis: Pitfalls and lessons
Authors: Miller Amanda J. , Perl Jeff , Tennankore Karthik K. 
Published: April 2017

AbstractThe optimal dose of hemodialysis (HD) has not yet been established. As a means of better approximating the physiology of native kidney function, there has been a growing interest in intensive HD (an increase in dialysis frequency and/or duration). Although many studies have demonstrated a survival benefit with intensive dialysis, results have been conflicting. This controversy stems from the challenges of randomizing patients to conventional vs. intensive HD modalities and, therefore, the reliance on observational comparisons that have been limited by varying definitions for intensive dialysis, differences in dialysis location and prescription, unavoidable treatment selection bias, and a potential lack of generalizability. This review will discuss the pitfalls and complexities surrounding survival comparisons with intensive HD, and identify important directions for future study.
Ascorbic acid triggered physiochemical transformations at different phenological stages of heat‐stressed Bt cotton
Authors: Kamal M. A. , Saleem M. F. , Shahid M. , Awais M. , Khan H. Z. , Ahmed K. 
Published: April 2017

AbstractHeat stress at reproductive stages of cotton crop is the main cause for instability in yield than other abiotic stresses of crops. An experiment was conducted to observe the impacts of heat stress at squaring and flowering stages of cotton and potential of exogenously applied ascorbic acid to alleviate this stress. The experiment was planted for two consecutive years, that is 2013 and 2014, in randomized complete block design with split plot arrangement having three replications. Treatments were comprised of heat stress in main plots, viz. H0 = no heat imposition; H1 = heat imposition at square initiation; H2 = heat imposition at flower initiation and foliar‐applied ascorbic acid in subplots, viz. A0 = control or water spray; A1 = 20 mg/L; A2 = 40 mg/L; and A3 = 60 mg/L. Results showed that heat stress badly affected plant water relations (relative water contents and osmotic potential), total chlorophyll contents and activities of antioxidant enzymes that led to a corresponding decrease in seed cotton yield. Foliar application of ascorbic acid (40–60 mg/L) ameliorated adverse effects of heat and thus helped the crop to improve its water relations, stay green and antioxidant enzymes resulting into better crop yield.
Microstructural evolution, non‐Ohmic properties, and giant dielectric response in CaCu3Ti4−xGexO12 ceramics
Authors: Boonlakhorn Jakkree , Thongbai Prasit , Putasaeng Bundit , Kidkhunthod Pinit , Maensiri Santi , Chindaprasirt Prinya 
Published: April 2017

AbstractThe microstructural evolution, non‐Ohmic properties, and giant dielectric properties of CaCu3Ti4−xGexO12 ceramics (x=0‐0.10) are systematically investigated. The Rietveld refinement confirms the existence of a pure CaCu3Ti4O12 phase in all samples. Significantly enlarged grain sizes of CaCu3Ti4−xGexO12 ceramics are associated with the liquid phase sintering mechanism. Enhanced dielectric permittivity from 6.90×104 to 1.08×105 can be achieved by increasing Ge4+ dopant from x=0‐0.10, whereas the loss tangent is remarkably reduced by a factor of ≈10. Non‐Ohmic properties are enhanced by Ge4+ doping ions. Using impedance and admittance spectroscopies, the underlying mechanisms for the dielectric and nonlinear properties are well described. The improved nonlinear properties and reduced loss tangent are attributed to the enhanced resistance and conduction activation energy of the grain boundaries. The largely enhanced permittivity is closely associated with the enlarged grain sizes and the increase in the Cu+/Cu2+ and Ti3+/Ti4+ ratios, which are calculated from the X‐ray absorption near‐edge structure.
Contrasting dispersal histories of broad‐ and fine‐leaved temperate Loliinae grasses: range expansion, founder events, and the roles of distance and barriers
Authors: Minaya Miguel , Hackel Jan , Namaganda Mary , Brochmann Christian , Vorontsova Maria S. , Besnard Guillaume , Catalán Pilar 
Published: April 2017

AbstractAimSuccessful colonization after long‐distance dispersal (LDD) depends on the availability of suitable habitats and competitive ability. In this study, we address the hypothesis that two widely distributed sister grass lineages (broad‐ and fine‐leaved Loliinae; hereafter BL and FL) that differ in their habitat requirements and competitive ability also differ in their biogeographic history, with particular reference to LDD.LocationGlobal.MethodsWe reconstructed a comprehensive phylogeny of Loliinae, based on nuclear and plastid markers and estimated divergence times using fossil calibrations. Biogeographical events were estimated using analysis of range evolution, comparing different models. Numbers and rates of dispersals were estimated for BL and FL using stochastic mapping with best‐performing and baseline biogeographical models, and examined for correlation with distance, disjunction type, and phenotypic syndrome.ResultsThe most recent common ancestor of Loliinae likely split at the Oligocene‐Miocene transition (22.50 ± 3.95 Ma), pre‐dating previous estimates, whereas the ancestors of the BL and FL Loliinae likely began to diversify in the Early Miocene (18.91 ± 4.15 and 17.50 ± 3.50 Ma, respectively). A model of range evolution integrating founder events and scaling of dispersal by shortest distance between areas performed best amongst a set of alternative models and recovered a mean of 83 dispersal events in Loliinae. Overall dispersal rates were significantly higher in BL than in FL. Per‐route dispersal rates showed a significant negative exponential relationship to shortest distance but were not affected by phenotypic syndrome or disjunction type.Main conclusionsLoliinae originated in the Northern Hemisphere and evolved through recurrent LDDs. Higher competitive ability, potentially related to the broad‐leaved syndrome (i.e. tall strong‐rhizomatous plants, long‐living individuals, occupancy of more stable habitats), may explain higher observed dispersal rates in BL compared with FL Loliinae. However, the dominant factor impacting dispersal in both BL and FL Loliinae is the distance between suitable areas.
Geographic variation in mimetic precision among different species of coral snake mimics
Authors: Akcali C. K. , Pfennig D. W. 
Published: April 2017

AbstractBatesian mimicry is widespread, but whether and why different species of mimics vary geographically in resemblance to their model is unclear. We characterized geographic variation in mimetic precision among four Batesian mimics of coral snakes. Each mimic occurs where its model is abundant (i.e. in ‘deep sympatry’), rare (i.e. at the sympatry/allopatry boundary or ‘edge sympatry’) and absent (i.e. in allopatry). Geographic variation in mimetic precision was qualitatively different among these mimics. In one mimic, the most precise individuals occurred in edge sympatry; in another, they occurred in deep sympatry; in the third, they occurred in allopatry; and in the fourth, precise mimics were not concentrated anywhere throughout their range. Mimicry was less precise in allopatry than in sympatry in only two mimics. We present several nonmutually exclusive hypotheses for these patterns. Generally, examining geographic variation in mimetic precision – within and among different mimics – offers novel insights into the causes and consequences of mimicry.
Association between endoscopic findings related to colonic diverticula and bowel habits: A multicenter study in Japan
Authors: Yamada Eiji , Kuriyama Hitoshi , Uchida Eri , Murata Yoriko , Hata Yasuo , Tagri Masataka , Isozaki Yutaka , Oyamada Hirokazu , Ozawa Yukihiro , Ito Takafumi , Mizuki Akira , Inamori Masahiko , Manabe Noriaki , Haruma Ken , Nakajima Atsushi 
Published: April 2017

AbstractBackground and AimFew studies have shown the associations between colonic diverticula and endoscopic findings such as location, inflammation, number of diverticula, sigmoid colon rigidity, and bowel habits.MethodsJapanese subjects who underwent total colonoscopies at six centers in Japan from November 2015 to October 2016 were analyzed. Bowel habits were evaluated using the Gastrointestinal Symptom Rating Scale. Location and number of diverticula, inflammation, and sigmoid colon rigidity were evaluated from endoscopy results.ResultsA total of 762 subjects (486 men and 276 women [ratio, 1.76:1]) whose mean age was 65.5 ± 11.4 years were evaluated. In multivariate analysis, presence of constipation was associated with a significantly lower likelihood of left‐sided colonic diverticula (odds ratio = 0.40, 95% confidence interval 0.20–0.82, P = 0.012), whereas right‐sided and bilateral‐sided colonic diverticula, multiple colonic diverticula, inflammation findings, and sigmoid colon rigidity were not related to bowel habits.ConclusionsAmong endoscopic findings related to colonic diverticula and bowel habits, only left‐sided colonic diverticula were inversely associated with constipation, whereas inflammation findings, multiple diverticula, and sigmoid colon rigidity were not related to bowel habits. However, the association of inflammation findings with colonic diverticula and bowel habits should be further studied. Investigation of changes in left‐sided colonic diverticula may lead to new treatments for constipation.
Drug resistance reversal by combretastatin-A4 phosphate loaded with doxorubicin in polymersomes independent of angiogenesis effect
Authors: Zhu Jinfang , Hu Mengying , Qiu Liyan 
Published: April 2017

Abstract

Objectives
This study aimed to evaluate that the polymersomes (Ps-DOX-CA4P) dual-loaded with combretastatin-A4 phosphate (CA4P) and doxorubicin (DOX) overcame drug resistance and sensitized tumour cells to chemotherapeutic drugs.

Methods
Ps-DOX-CA4P were prepared by solvent evaporation method using mPEG-b-PLA as carriers. The potential capability of CA4P to reverse DOX resistance was verified by cytotoxicity test, apoptosis assay and cellular uptake of DOX. The comparison between free drugs and drug-loaded polymersomes was also made on a single-layer cell model and multicellular tumour spheroids to display the superiority of the drug vehicles. Furthermore, we put the emphasis on the investigation into underlying mechanisms for CA4P overcoming DOX resistance.

Key findings
Results showed Ps-DOX-CA4P achieved increased uptake of DOX, enhanced cytotoxicity and apoptotic rate in MCF-7/ADR cells as well as MCF-7/ADR tumour spheroids. The potential molecular mechanisms may be related to inhibiting P-glycoprotein function by downregulating protein kinase Cα, stimulating ATPase activity, depleting ATP and increasing intracellular reactive oxygen species levels.

Conclusions
The findings validated the sensitization property of CA4P on DOX independent of its well-known angiogenesis effect, which would provide a novel and promising strategy for drug-resistant cancer therapy.
Thank god it's Friday – sleep improved
Authors: Petersen Helena , Kecklund Göran , D'Onofrio Paolo , Axelsson John , Åkerstedt Torbjörn 
Published: April 2017

SummaryThe weekend is usually seen as a window of recovery. Thus, sleep before a day off may be less impaired than that before a workday. However, very few polysomnographical studies have investigated this hypothesis. Therefore, the aim of the present study was to compare sleep before a workday with that before a weekend. Seventeen teachers participated. Sleep was recorded with polysomnography on one weekday night during the workweek, and on a workday (Friday) followed by a day off. Sleep diaries and actigraphs were also used. Weekend sleep showed delayed bedtime and time of rising, a longer total sleep time (45 min), increased N3 and N1, and decreased N2 and REM. Sleep spindles were reduced. The results remained after truncation to the shortest common sleep duration (5 h). The increase in N3 from weekday sleep to Friday night sleep was positively correlated with N1 change (r = 0.853, P ≤ 0.001), and negatively correlated with N2 change (r = −0.614, P ≤ 0.001). Subjective ratings showed that weekend sleep was associated with less awakening problems and lower subjective arousal during the day. The authors concluded that weekend sleep was longer, and showed increased N3 and N1. The authors suggest that the N3 increase before the day off is a result of lower stress, while the N1 increase may be an effect of sleep spindle suppression via the increase of N3 (which would suppress sleep spindles), thus reducing N2 and enhancing N1.
Prevalence of Gastroesophageal Reflux in Cats During Anesthesia and Effect of Omeprazole on GastricpH
Authors: Garcia R.S. , Belafsky P.C. , Della Maggiore A. , Osborn J.M. , Pypendop B.H. , Pierce T. , Walker V.J. , Fulton A. , Marks S.L. 
Published: April 2017

BackgroundGastroesophageal reflux (GER) is poorly characterized in anesthetized cats, but can cause aspiration pneumonia, esophagitis, and esophageal stricture formation.ObjectiveTo determine whether pre‐anesthetic orally administered omeprazole increases gastric and esophagealpHand increases serum gastrin concentrations in anesthetized cats, and to determine the prevalence ofGERusing combined multichannel impedance andpHmonitoring.AnimalsTwenty‐seven healthy cats undergoing elective dental procedures.MethodsProspective, double‐masked, placebo‐controlled, randomized clinical trial. Cats were randomized to receive 2POdoses of omeprazole (1.45–2.20 mg/kg) or an empty gelatin capsule placebo 18–24 hours and 4 hours before anesthetic induction. Blood for measurement of serum gastrin concentration was collected during anesthetic induction. An esophagealpH/impedance catheter was utilized to continuously measure esophagealpHand detectGERthroughout anesthesia.ResultsMean gastricpHin the cats that received omeprazole was 7.2 ± 0.4 (range, 6.6–7.8) and was significantly higher than thepHin cats that received the placebo 2.8 ± 1.0 (range, 1.3–4.1;P< .001). Omeprazole administration was not associated with a significant increase in serum gastrin concentration (P= .616). Nine of 27 cats (33.3%) had ≥1 episode ofGERduring anesthesia.Conclusions and Clinical RelevancePre‐anesthetic administration of 2POdoses of omeprazole at a dosage of 1.45–2.20 mg/kg in cats was associated with a significant increase in gastric and esophagealpHwithin 24 hours, but was not associated with a significant increase in serum gastrin concentration. Prevalence of reflux events in cats during anesthesia was similar to that of dogs during anesthesia.
Alterations in mandibular morphology associated with glypican 1 and glypican 3 gene mutations
Authors: Mian M. , Ranjitkar S. , Townsend G. C. , Anderson P. J. 
Published: April 2017

Structured AbstractObjectivesGlypican 1 (GPC1) and glypican 3 (GPC3) are bone co‐regulators that act downstream in many of the signalling pathways associated with craniosynostosis. Morphometric data from GPC‐knockout mice were analysed to determine whether elimination of GPC1 and GPC3 genes would alter mandibular morphology.Setting and sample populationThe murine model included five male and five female mandibles in each of GPC1‐knockout, GPC1/GPC3‐knockout and wild‐type (control) groups. Female GPC3‐knockout mice had a very high rate of perinatal lethality, and therefore, only five males were included in this group.MethodsThe mandibular morphology of GPC1‐knockout (n=10), GPC3‐knockout (n=5), GPC1/GPC3‐knockout (n=10) and wild‐type (n=10) mice was compared by analysing five landmark‐based linear dimensions: anterior and posterior lengths, as well as ascending, descending and posterior heights. Measurements were recorded on three‐dimensional micro‐CT reconstructions.ResultsGPC3‐knockout mandibles were larger than wild‐type mandibles for all dimensions (P<.05). Mandibular heights were more affected than lengths. A decreasing trend of mandibular dimensions across the mouse groups (GPC3‐knockout>GPC1/GPC3‐knockout>GPC1‐knockout=wild‐type) (P<.05) indicated that an increase in mandibular size was associated with increased GPC3 expression, but not GPC1.ConclusionsAlterations in GPC3 expression are likely to mediate changes to mandibular size in craniosynostosis. These findings have potential future applications in the prevention and treatment of craniosynostosis and associated craniofacial dysmorphology.
“Nails Only” Phenotype and Partial Dominance of p.Glu170Lys Mutation in a Family with Epidermolysis Bullosa Simplex
Authors: González‐Cantero Álvaro , Sánchez‐Moya Ana Isabel , Pérez‐Hortet Cristina , Martínez‐Lorenzo Elena , Gómez‐Dorado Blas , Schoendorff‐Ortega Cristina 
Published: April 2017

AbstractEpidermolysis bullosa (EB) is a heterogeneous group of rare, chronic, inherited skin disorders characterized by marked mechanical fragility of epithelial tissues, with blistering and erosions after minor trauma. We present the first report of a nails‐only phenotype in two patients with epidermolysis bullosa simplex (EBS) and a heterozygous pGlu170Lys mutation and the second reported case of EBS associated with a homozygous p.Glu170Lys mutation in the KRT5 gene. Our findings may be relevant for genetic counseling and for understanding the inheritance pattern of EBS.
Mutations in sdh genes in field isolates of Zymoseptoria tritici and impact on the sensitivity to various succinate dehydrogenase inhibitors
Authors: Rehfus A. , Strobel D. , Bryson R. , Stammler G. 
Published: April 2017

Zymoseptoria tritici is the causal agent of septoria tritici blotch (STB), a foliar wheat disease important worldwide. Succinate dehydrogenase inhibitors (SDHIs) have been used in cereals for effective control of STB for several years, but resistance towards SDHIs has been reported in several phytopathogenic fungi. Resistance mechanisms are target‐site mutations in the genes coding for subunits B, C and D of the succinate dehydrogenase (SDH) enzyme. Previous monitoring data in Europe indicated the presence of single isolates of Z. tritici with reduced SDHI sensitivity. These isolates carried mutations leading to amino acid exchanges: C‐T79N, C‐W80S in 2012; C‐N86S in 2013; B‐N225T and C‐T79N in 2014; and C‐V166M, B‐T268I, C‐N86S, C‐T79N and C‐H152R in 2015. The current study provides results from microtitre and greenhouse experiments to give an insight into the impact of different mutations in field isolates on various SDHIs. In microtitre tests, the highest EC50 values for all tested SDHIs were obtained with mutants carrying C‐H152R. Curative greenhouse tests with various SDHIs confirmed the findings of microtitre tests that isolates with C‐H152R are, in general, controlled with lower efficacy than isolates carrying B‐T268I, C‐T79N and C‐N86S. SDHI‐resistant isolates of Z. tritici found in the field were shown to have cross‐resistance towards all SDHIs tested. So far, SDHI‐resistant isolates of Z. tritici have been found in low frequencies in Europe. Therefore, FRAC recommendations for resistance management in cereals, including a limited number of applications, alternation and combination with other MOAs, should be followed to prolong SDHI field efficacy.