bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross‐genotype‐specific T‐cell responses in acute hepatitis E virus (HEV) infection
Authors: Gisa A. , Suneetha P. V. , Behrendt P. , Pischke S. , Bremer B. , Falk C. S. , Manns M. P. , Cornberg M. , Wedemeyer H. , Kraft A. R. M. 
Published: February 2016

SummaryHepatitis E is an inflammatory liver disease caused by infection with the hepatitis E virus (HEV). In tropical regions, HEV is highly endemic and predominantly mediated by HEV genotypes 1 and 2 with >3 million symptomatic cases per year and around 70 000 deaths. In Europe and America, the zoonotic HEV genotypes 3 and 4 have been reported with continues increasing new infections per year. So far, little is known about T‐cell responses during acute HEV genotype 3 infection. Therefore, we did a comprehensive study investigating HEV‐specific T‐cell responses using genotypes 3‐ and 1‐specific overlapping peptides. Additional cytokines and chemokines were measured in the plasma. In four patients, longitudinal studies were performed. Broad functional HEV‐specific CD4+ and CD8+ T‐cell responses were detectable in patients acutely infected with HEV genotype 3. Elevated of pro‐ and anti‐inflammatory cytokine levels during acute HEV infection correlated with ALT levels. Memory HEV‐specific T‐cell responses were detectable up to >1.5 years upon infection. Importantly, cross‐genotype HEV‐specific T‐cell responses (between genotypes 1 and 3) were measurable in all investigated patients. In conclusion, we could show for the first time HEV‐specific T‐cell responses during and after acute HEV genotype 3 infection. Our data of cross‐genotype HEV‐specific T‐cell responses might suggest a potential role in cross‐genotype‐specific protection between HEV genotypes 1 and 3.
Soil pH limits of forest vascular plants determine range size and threat level
Authors: Michaelis Jana , Pannek Angela , Diekmann Martin 
Published: February 2016

AbstractQuestionsKnowledge about the response curves of species along soil variable gradients is scarce. Because environmental change may force species to live closer to their ecological limits than optima, we examined and compared the importance of response limits, response optima and Ellenberg indicator values for soil pH to determine the regional range sizes and threat levels of species.LocationDeciduous forests in the lowlands and uplands of northern Germany.MethodsWe used Huisman–Olff–Fresco models to examine the species responses of forest vascular plants along a soil pH gradient with a particular focus on rare species. Separately for the two regions, the optima and limits across all species were related to range size, change in regional range size over the past decades and threat level.ResultsLower pH limits showed an aggregation around pH 4, and were consistent across regions, whereas upper pH limits were not clumped and not significantly correlated between regions. In the lowlands, species with relatively large lower pH limits were less widespread, had decreased more over time and were more threatened than species able to grow on very acid soils. Lower limits were more closely related to regional range size and rarity than optima and Ellenberg R values. These patterns were not found for upland species, probably due to a more complex interaction between pH and other soil factors.ConclusionThe results reinforce the importance of soil variables and their interactions for the occurrence of plant species, and suggest that limits may be better predictors of current and future species distributions than optima and Ellenberg indicator values. Still, crucial information is missing even for common species. Therefore, there is an urgent need for more and better species occurrence data relative to edaphic factors in order to identify the species' needs and their potential responses to environmental change.
Understanding clonal plant competition for space over time: a fine‐scale spatial approach based on experimental communities
Authors: Saiz Hugo , Bittebiere Anne‐Kristel , Benot Marie‐Lise , Jung Vincent , Mony Cendrine 
Published: February 2016

AbstractAimsCompetitive interactions are a determinant driver of plant community structure in temperate grasslands. In such dense vegetation cover, competition mostly occurs over free space, which conditions niche availability. Clonal growth determines how plants exploit horizontal space, by (1) exploring and colonizing free patches (guerilla form) or (2) resisting competitors through space consolidation (phalanx form), with possible intermediate strategies. Few studies have explored the dynamics of co‐existing plants belonging to different clonal strategies. Models predict that guerilla forms may be advantageous during the early stages of succession, whereas phalanx forms are expected to be better competitors over time. We investigated whether these predictions are true under experimental conditions and explored possible mechanisms that promote clonal plant co‐existence.LocationExperimental garden of the University of Rennes 1, France.MethodsWe set up a large‐scale mesocosm, in which we manipulated different mixtures of three clonal growth forms (guerilla, intermediate and phalanx) over 5 yr (2009–2014), which impeded all types of reproduction other than clonal spread of the initial planted individuals. We analysed the spatio‐temporal dynamics of the communities using linear mixed models to compare the change in relative cover and spatial association (differentiating between associations with similar and different species) for each clonal form.ResultsGuerilla forms dominated the early community, but decreased in dominance at later stages, at which point intermediate forms benefitted. Furthermore, guerilla forms were more likely to co‐occur with other guerrillas, with this pattern remaining consistent over time. In contrast, and contrary to our expectations, phalanx forms had the lowest cover throughout the experiment, and exhibited clear segregation from intermediate or other phalanx species. Intermediate growth forms between guerilla and phalanx were the most variable over time, displaying both consolidative and explorative patterns depending on the clonal forms of the other species which they coexisted with, suggesting plastic variation in their traits.ConclusionsOur results highlight the key role of clonal forms in driving competitive interactions and, hence, determining the spatio‐temporal dynamics of grassland communities.
Fine‐scale patterns in the day, night and crepuscular composition of a temperate reef fish assemblage
Authors: Myers Elisabeth M. V. , Harvey Euan S. , Saunders Benjamin J. , Travers Michael J. 
Published: February 2016

AbstractThe distribution, abundance and composition of marine fish assemblages are influenced by changes in behaviour and movement associated with the diel cycle. The majority of studies exploring day–night differences have demonstrated that there is a greater abundance and diversity of fishes during diurnal compared with nocturnal hours, and that fish assemblage composition varies with time of day or night. We investigated fine‐scale (hourly) diel cycles in the composition and relative abundance of temperate reef fishes using unbaited remote underwater video systems. We observed short crepuscular changeover periods with the hours around dawn and dusk sharing many species, some of which are nocturnal and others diurnal. Diurnal surveys recorded a greater number of individuals (16,990) and species (70) than nocturnal surveys (1053 individuals and 19 species). There was a clear difference between the diurnal assemblage, which was characterized by benthic invertivores, and the nocturnal assemblage composition, which contained zooplanktivores and generalist feeders. Within the diurnal period the hourly temporal variation was relatively homogenous, indicating that standardization of diurnal sampling to a particular time of day may not be necessary.
Spatiotemporal choreography of chromosome and megaplasmids in the Sinorhizobium meliloti cell cycle
Authors: Frage Benjamin , Döhlemann Johannes , Robledo Marta , Lucena Daniella , Sobetzko Patrick , Graumann Peter L. , Becker Anke 
Published: February 2016

SummaryA considerable share of bacterial species maintains multipartite genomes. Precise coordination of genome replication and segregation with cell growth and division is vital for proliferation of these bacteria. The α‐proteobacterium Sinorhizobium meliloti possesses a tripartite genome composed of one chromosome and the megaplasmids pSymA and pSymB. Here, we investigated the spatiotemporal pattern of segregation of these S. meliloti replicons at single cell level. Duplication of chromosomal and megaplasmid origins of replication occurred spatially and temporally separated, and only once per cell cycle. Tracking of FROS (fluorescent repressor operator system)‐labelled origins revealed a strict temporal order of segregation events commencing with the chromosome followed by pSymA and then by pSymB. The repA2B2C2 region derived from pSymA was sufficient to confer the spatiotemporal behaviour of this megaplasmid to a small plasmid. Altering activity of the ubiquitous prokaryotic replication initiator DnaA, either positively or negatively, resulted in an increase in replication initiation events or G1 arrest of the chromosome only. This suggests that interference with DnaA activity does not affect replication initiation control of the megaplasmids.
The cystathionine‐β‐synthase domains on the guanosine 5′’‐monophosphate reductase and inosine 5′‐monophosphate dehydrogenase enzymes from Leishmania regulate enzymatic activity in response to guanylate and adenylate nucleotide levels
Authors: Smith Sabrina , Boitz Jan , Chidambaram Ehzilan Subramanian , Chatterjee Abhishek , Ait‐Tihyaty Maria , Ullman Buddy , Jardim Armando 
Published: February 2016

SummaryThe Leishmania guanosine 5′‐monophosphate reductase (GMPR) and inosine 5′‐monophosphate dehydrogenase (IMPDH) are purine metabolic enzymes that function maintaining the cellular adenylate and guanylate nucleotide. Interestingly, both enzymes contain a cystathionine‐β‐synthase domain (CBS). To investigate this metabolic regulation, the Leishmania GMPR was cloned and shown to be sufficient to complement the guaC (GMPR), but not the guaB (IMPDH), mutation in Escherichia coli. Kinetic studies confirmed that the Leishmania GMPR catalyzed a strict NADPH‐dependent reductive deamination of GMP to produce IMP. Addition of GTP or high levels of GMP induced a marked increase in activity without altering the Km values for the substrates. In contrast, the binding of ATP decreased the GMPR activity and increased the GMP Km value 10‐fold. These kinetic changes were correlated with changes in the GMPR quaternary structure, induced by the binding of GMP, GTP, or ATP to the GMPR CBS domain. The capacity of these CBS domains to mediate the catalytic activity of the IMPDH and GMPR provides a regulatory mechanism for balancing the intracellular adenylate and guanylate pools.
Automated identification and clustering of subunits within delphinid vocalizations
Authors: Frasier Kaitlin E. , Elizabeth Henderson E. , Bassett Hannah R. , Roch Marie A. 
Published: February 2016

AbstractTonal vocalizations or whistles produced by many species of delphinids range from simple tones to complex frequency contours. Whistle structure varies in duration, frequency, and composition between delphinid species, as well as between populations and individuals. Categorization of whistles may be improved by decomposition of complex calls into simpler subunits, much like the use of phonemes in classification of human speech. We identify a potential whistle decomposition scheme and normalization process to facilitate comparison of whistle subunits derived from tonal vocalizations of bottlenose dolphins (Tursiops truncatus), spinner dolphins (Stenella longirostris), and short‐beaked common dolphins (Delphinus delphis). Network analysis is then used to compare subunits within the vocal corpus of each species. By processing whistles through a series of steps including segmentation, normalization, and dynamic time warping, we are able to automatically cluster selected subunits by shape, regardless of differences in absolute frequency or moderate differences in duration. Using the clustered subunits, we demonstrate a preliminary species classification scheme based on rates of subunit occurrence in vocal repertoires. This provides a potential mechanism for comparing the structure of complex vocalizations within and between species.
Novel Percutaneous Epicardial Autonomic Modulation in the Canine for Atrial Fibrillation: Results of an Efficacy and Safety Study
Authors: MADHAVAN MALINI , VENKATACHALAM K.L. , SWALE MATTHEW J. , DESIMONE CHRISTOPHER V. , GARD JOSEPH J. , JOHNSON SUSAN B. , SUDDENDORF SCOTT H. , MIKELL SUSAN B. , LADEWIG DOROTHY J. , NOSBUSH TONI GRABINGER , DANIELSEN ANDREW J. , KNUDSON MARK , ASIRVATHAM SAMUEL J. 
Published: February 2016

BackgroundEndocardial ablation of atrial ganglionated plexi (GP) has been described for treatment of atrial fibrillation (AF). Our objective in this study was to develop percutaneous epicardial GP ablation in a canine model using novel energy sources and catheters.MethodsPhase 1: The efficacy of several modalities to ablate the GP was tested in an open chest canine model (n = 10). Phase 2: Percutaneous epicardial ablation of GP was done in six dogs using the most efficacious modality identified in phase 1 using two novel catheters.ResultsPhase 1: Direct current (DC) in varying doses (blocking [7–12 μA], electroporation [300–500 μA], ablation [3,000–7,500 μA]), radiofrequency ablation (25–50 W), ultrasound (1.5 MHz), and alcohol (2–5 mL) injection were successful at 0/8, 4/12, 5/7, 3/8, 1/5, and 5/7 GP sites. DC (500–5,000 μA) along with alcohol irrigation was tested in phase 2. Phase 2: Percutaneous epicardial ablation of the right atrium, oblique sinus, vein of Marshall, and transverse sinus GP was successful in 5/6 dogs. One dog died of ventricular fibrillation during DC ablation at 5,000 μA. Programmed stimulation induced AF in six dogs, preablation and no atrial arrhythmia in three, flutter in one, and AF in one postablation. Heart rate, blood pressure, effective atrial refractory period, and local atrial electrogram amplitude did not change significantly postablation. Microscopic examination showed elimination of GP, and minimal injury to atrial myocardium.ConclusionPercutaneous epicardial ablation of GP using DC and novel catheters is safe and feasible and may be used as an adjunct to pulmonary vein isolation in the treatment of AF in order to minimize additional atrial myocardial ablation.
A novel ATM‐dependent checkpoint defect distinct from loss of function mutation promotes genomic instability in melanoma
Authors: Spoerri Loredana , Brooks Kelly , Chia KeeMing , Grossman Gavriel , Ellis Jonathan J. , Dahmer‐Heath Mareike , Škalamera Dubravka , Pavey Sandra , Burmeister Bryan , Gabrielli Brian 
Published: February 2016

SummaryMelanomas have high levels of genomic instability that can contribute to poor disease prognosis. Here, we report a novel defect of the ATM‐dependent cell cycle checkpoint in melanoma cell lines that promotes genomic instability. In defective cells, ATM signalling to CHK2 is intact, but the cells are unable to maintain the cell cycle arrest due to elevated PLK1 driving recovery from the arrest. Reducing PLK1 activity recovered the ATM‐dependent checkpoint arrest, and over‐expressing PLK1 was sufficient to overcome the checkpoint arrest and increase genomic instability. Loss of the ATM‐dependent checkpoint did not affect sensitivity to ionizing radiation demonstrating that this defect is distinct from ATM loss of function mutations. The checkpoint defective melanoma cell lines over‐express PLK1, and a significant proportion of melanomas have high levels of PLK1 over‐expression suggesting this defect is a common feature of melanomas. The inability of ATM to impose a cell cycle arrest in response to DNA damage increases genomic instability. This work also suggests that the ATM‐dependent checkpoint arrest is likely to be defective in a higher proportion of cancers than previously expected.
Relationship Between Mean Leucocyte Telomere Length and Measures of Allostatic Load in US Reproductive‐Aged Women, NHANES 1999–2002
Authors: Ahrens Katherine A. , Rossen Lauren M. , Simon Alan E. 
Published: February 2016

AbstractBackgroundReproductive health disparities may be partly explained by the cumulative effects of chronic stress experienced by socially disadvantaged groups. Although, telomere length (TL) and allostatic load score have each been used as biological markers of stress, the relationship between these two measures is unknown.MethodsWe investigated the association between leucocyte TL and allostatic load score in 1503 non‐pregnant women (20–44 years) participating in the National Health and Nutrition Examination Survey, 1999–2002. We constructed six different allostatic load scores using either quartile‐ or clinical‐based cut‐points for 14 biomarkers based on previously published methods. We estimated associations between TL and allostatic load scores and component biomarkers using linear regression, also assessing interactions by race/ethnicity.ResultsAfter adjustment for age, longer TL was associated with higher HDL cholesterol and lower C‐reactive protein and creatinine clearance; TL was not associated with the other component biomarkers. Shorter TL was associated with higher allostatic load scores for the two clinical cut‐point‐based scores after adjustment for age, but not the four scores based on quartile cut‐points. Significant interactions by race/ethnicity were observed for TL and HbA1c and triglycerides, but not for other component biomarkers or allostatic load scores.ConclusionsAlthough TL and allostatic load score are both considered measures of cumulative stress, most component biomarkers and scores using quartile‐based cut‐points were not associated with TL. In reproductive‐aged women, allostatic load scores using clinical‐based cut‐points were more strongly associated with TL compared with quartile‐based scores.
Deficient attention modulation of lateralized alpha power in schizophrenia
Authors: Kustermann Thomas , Rockstroh Brigitte , Kienle Johanna , Miller Gregory A. , Popov Tzvetan 
Published: February 2016

AbstractModulation of 8–14 Hz (alpha) activity in posterior brain regions is associated with covert attention deployment in visuospatial tasks. Alpha power decrease contralateral to to‐be‐attended stimuli is believed to foster subsequent processing, such as retention of task‐relevant input. Degradation of this alpha‐regulation mechanism may reflect an early stage of disturbed attention regulation contributing to impaired attention and working memory commonly found in schizophrenia. The present study tested this hypothesis of early disturbed attention regulation by examining alpha power modulation in a lateralized cued delayed response task in 14 schizophrenia patients (SZ) and 25 healthy controls (HC). Participants were instructed to remember the location of a 100‐ms saccade‐target cue in the left or right visual hemifield in order to perform a delayed saccade to that location after a retention interval. As expected, alpha power decrease during the retention interval was larger in contralateral than ipsilateral posterior regions, and SZ showed less of this lateralization than did HC. In particular, SZ failed to show hemifield‐specific alpha modulation in posterior right hemisphere. Results suggest less efficient modulation of alpha oscillations that are considered critical for attention deployment and item encoding and, hence, may affect subsequent spatial working memory performance.
Characteristics of Antioxidant Systems of Yellow Fraction of Red Deer's (Cervus elaphus L.) Semen During the Rutting Period
Authors: Koziorowska‐Gilun M , Szurnicka M , Dziekonska A , Kordan W , Giżejewski Z , Filipowicz K 
Published: February 2016

ContentsThe objective of this study was to make the preliminary characterization of the antioxidant defence systems of the yellow fraction (YF) of red deer's (Cervus elaphus L.) semen during the rutting period. The semen was collected using artificial vagina (AV). The studies included spectrophotometric determination of antioxidant enzymes activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). We also analysed the contents of low‐molecular antioxidants such as L‐glutathione (GSH + GSSG), L‐ascorbate (ASC) and total antioxidant status (TAS). Additionally, the samples were subjected to PAGE and stained for SOD and GPx activities. It was demonstrated that the yellow fraction exhibited activities of SOD and GPx, with the highest activities in September and October. CAT activity was not detected. Staining for the SOD and GPx activities confirmed three protein bands with SOD activity and one protein band with GPx activity. The content of GSH + GSSG was similar in trials dating from October to December contrary to the content of ASC which was high in samples from September and October. The stable rate of TAS was observed during the whole rutting period. The results of this study showed that the YF of red deer semen is equipped with basic battery of antioxidant enzymes comprising SOD and GPx, with the supporting role of GSH + GSSG and ASC. Moreover, the samples obtained at the peak of the rutting period occurring from September to October had the highest enzymatic activity in comparison with remaining months of the rutting period, which contributed to the high quality of the semen by preventing it from the formation of oxidative stress during the short period of intense sexual activity of male red deer. The better understanding of the mechanisms of antioxidant defence systems in the YF of deer's semen may contribute to the potential use of this fraction in technology of wild ruminant semen preservation.
Successful Vitrification of In vivo Embryos Collected from Superovulated Japanese Black Cattle (Wagyu)
Authors: An L , Ling PP , Zhu X , Liu Y , Zhang F , Ma X , Xu B , Wang Y , Du Z , Yang L , Xue F , Bella A , Presicce GA , Du F 
Published: February 2016

ContentThe aim of this study was to determine whether vitrification is an effective method when used for Japanese Black Cattle (Wagyu) in vivo‐derived embryos, collected following a superovulation treatment and embryo transfer (MOET) programme. In vivo‐derived morula and blastocysts collected on day 7 after artificial insemination, were vitrified using a modified droplet vitrification (MDV) procedure and subsequently warmed for transfer (ET) into synchronized recipients. Fresh embryos, and embryos cryopreserved using a standardized slow freezing procedure (direct thaw/direct transfer, DT) served as ET controls. Two different follicle‐stimulating hormone (FSH) sources, Folltropin® Canada (FSH BAH, 24 donors) and a brand prepared by the Chinese Academy of Science (FSH CAS, 16 donors), were compared in a series of superovulation outcomes following well‐established FSH administration protocols. Following data analysis, the total number of ovulations recorded at the time of embryo flushing (10.5 vs 8.5; p = 0.28) and the total number of transferable embryos (6.2 vs 5.1; p = 0.52) were similar between the two FSH sources. ET for MDV (39.7%, n = 78), DT (35.2%, n = 71) and fresh controls (47.1%, n = 34) resulted in similar pregnancy rates (p > 0.05). When MDV was used, a higher pregnancy rate (42.6%) resulted from the transfer of vitrified morulae, when compared to the DT counterparts (24.3%), (p = 0.05). Transfer of vitrified morulae resulted also in higher pregnancy rate, when compared to the transfer of vitrified blastocysts (42.6% vs. 29.4%; p < 0.05). Transfer of DT blastocysts resulted in higher pregnancy rate than morulae, similarly cryopreserved (47.1% vs. 24.3%, p < 0.05). In conclusion, MDV is an effective alternative methodology for cryopreservation of in vivo‐derived embryos. This study gives also indication that, compared to vitrified blastocysts, MDV of morula stage embryos results in higher pregnancy rates following warming and transfer into synchronized recipients.