bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photosynthesis and growth reduction with warming are driven by nonstomatal limitations in a Mediterranean semi‐arid shrub
Authors: León‐Sánchez Lupe , Nicolás Emilio , Nortes Pedro A. , Maestre Fernando T. , Querejeta José I. 
Published: March 2016

AbstractWhereas warming enhances plant nutrient status and photosynthesis in most terrestrial ecosystems, dryland vegetation is vulnerable to the likely increases in evapotranspiration and reductions in soil moisture caused by elevated temperatures. Any warming‐induced declines in plant primary production and cover in drylands would increase erosion, land degradation, and desertification. We conducted a four‐year manipulative experiment in a semi‐arid Mediterranean ecosystem to evaluate the impacts of a ~2°C warming on the photosynthesis, transpiration, leaf nutrient status, chlorophyll content, isotopic composition, biomass growth, and postsummer survival of the native shrub Helianthemum squamatum. We predicted that warmed plants would show reduced photosynthetic activity and growth, primarily due to the greater stomatal limitation imposed by faster and more severe soil drying under warming. On average, warming reduced net photosynthetic rates by 36% across the study period. Despite this strong response, warming did not affect stomatal conductance and transpiration. The reduction of peak photosynthetic rates with warming was more pronounced in a drought year than in years with near‐average rainfall (75% and 25–40% reductions relative to controls, respectively), with no indications of photosynthetic acclimation to warming through time. Warmed plants had lower leaf N and P contents, δ13C, and sparser and smaller leaves than control plants. Warming reduced shoot dry mass production by 31%. However, warmed plants were able to cope with large reductions in net photosynthesis, leaf area, and shoot biomass production without changes in postsummer survival rates. Our findings highlight the key role of nonstomatal factors (biochemical and/or nutritional) in reducing net carbon assimilation rates and growth under warming, which has important implications for projections of plant carbon balance under the warmer and drier climatic scenario predicted for drylands worldwide. Projected climate warming over the coming decades could reduce net primary production by about one‐third in semi‐arid gypsum shrublands dominated by H. squamatum.
Genetic variation at the MHC DRB1 locus is similar across Gunnison's prairie dog (Cynomys gunnisoni) colonies regardless of plague history
Authors: Cobble Kacy R. , Califf Katy J. , Stone Nathan E. , Shuey Megan M. , Birdsell Dawn N. , Colman Rebecca E. , Schupp James M. , Aziz Maliha , Van Andel Roger , Rocke Tonie E. , Wagner David M. , Busch Joseph D. 
Published: March 2016

AbstractYersinia pestis was introduced to North America around 1900 and leads to nearly 100% mortality in prairie dog (Cynomys spp.) colonies during epizootic events, which suggests this pathogen may exert a strong selective force. We characterized genetic diversity at an MHC class II locus (DRB1) in Gunnison's prairie dog (C. gunnisoni) and quantified population genetic structure at the DRB1 versus 12 microsatellite loci in three large Arizona colonies. Two colonies, Seligman (SE) and Espee Ranch (ES), have experienced multiple plague‐related die‐offs in recent years, whereas plague has never been documented at Aubrey Valley (AV). We found fairly low allelic diversity at the DRB1 locus, with one allele (DRB1*01) at high frequency (0.67–0.87) in all colonies. Two other DRB1 alleles appear to be trans‐species polymorphisms shared with the black‐tailed prairie dog (C. ludovicianus), indicating that these alleles have been maintained across evolutionary time frames. Estimates of genetic differentiation were generally lower at the MHC locus (FST = 0.033) than at microsatellite markers (FST = 0.098). The reduced differentiation at DRB1 may indicate that selection has been important for shaping variation at MHC loci, regardless of the presence or absence of plague in recent decades. However, genetic drift has probably also influenced the DRB1 locus because its level of differentiation was not different from that of microsatellites in an FST outlier analysis. We then compared specific MHC alleles to plague survivorship in 60 C. gunnisoni that had been experimentally infected with Y. pestis. We found that survival was greater in individuals that carried at least one copy of the most common allele (DRB1*01) compared to those that did not (60% vs. 20%). Although the sample sizes of these two groups were unbalanced, this result suggests the possibility that this MHC class II locus, or a nearby linked gene, could play a role in plague survival.
Evaluating the effects of laboratory protocols on eDNA detection probability for an endangered freshwater fish
Authors: Piggott Maxine P. 
Published: March 2016

AbstractThe effectiveness and accuracy of detection using environmental DNA (eDNA) is dependent on understanding the influence laboratory methods such as DNA extraction and PCR strategies have on detection probability. Ideally choice of sampling and extraction method will maximize eDNA yield and detection probability. Determining the survey effort required to reach a satisfactory detection probability (via increased PCR replicates or more sampling) could compensate for a lower eDNA yield if the sampling and extraction method has other advantages for a study, species or system. I analysed the effect of three different sampling and extraction methods on eDNA yield, detection probability and PCR replication for detecting the endangered freshwater fish Macquaria australasica from water samples. The impact of eDNA concentration, PCR strategy, target amplicon size and two marker regions: 12S (a mitochondrial gene) and 18S (a nuclear gene) was also assessed. The choice of sampling and extraction method and PCR strategy, rather than amplicon size and marker region, had the biggest effect on detection probability and PCR replication. The PCR replication effort required to achieve a detection probability of 0.95, ranged from 2 to 6 PCR replicates depending on the laboratory method used. As all methods yielded eDNA from which M. australasica was detected using the three target amplicons, differences in eDNA yield and detection probability between the three methods could be mitigated by determining the appropriate PCR replication effort. Evaluating the effect sampling and extraction methods will have on the detection probability and determining the laboratory protocols and PCR replication required to maximize detection and minimize false positives and negatives is a useful first step for eDNA occupancy studies.
River–groundwater interactions in salmon spawning habitat: riverbed flow dynamics and non‐stationarity in an end member mixing model
Authors: Neumann N.N. , Curtis P.J. 
Published: March 2016

AbstractSalmonids commonly spawn in locations of upwelling vertical flow, but it is unclear whether this upwelling water is groundwater, river water which has spent some time flowing through the riverbed before re‐emerging downstream or some mixture of the two. Vertical specific discharge and riverbed water chemistry were monitored in spawning habitat of Sockeye (Oncorhynchus nerka) and Chinook Salmon (Oncorhynchus tshawytscha) in contiguous natural and modified sections of Okanagan River in southern British Columbia, Canada. A quasi‐stationary end member mixing model was developed to describe mixing between end members as well as hydrochemical modification along a subsurface flowpath. For this work, a hydrochemical category called ‘hyporheic water’ was defined as river water which spent some time flowing within the riverbed and developed a distinct chemistry. The resulting mixing triangle was used to categorise intragravel water chemistry as (1) river‐like, (2) mixed river and regional groundwater, (3) hyporheic water or (4) mixed hyporheic and regional groundwater. Sockeye Salmon spawned in locations with all combinations of vertical specific discharge and intragravel water chemistry, which was interpreted as a high degree of habitat use plasticity. Chinook Salmon redds were more common where regional groundwater mixed with river or hyporheic water in locations with upwelling or near‐neutral vertical specific discharge. Current efforts at restoring or enhancing salmonid spawning habitat can be improved by considering the subsurface flow dynamic needs of different target species. Copyright © 2016 John Wiley & Sons, Ltd.
Long‐term excess mortality in takotsubo cardiomyopathy: predictors, causes and clinical consequences
Authors: Stiermaier Thomas , Moeller Christian , Oehler Katrin , Desch Steffen , Graf Tobias , Eitel Charlotte , Vonthein Reinhard , Schuler Gerhard , Thiele Holger , Eitel Ingo 
Published: March 2016

AbstractAimsDespite increasing research efforts, the prognostic consequences of takotsubo cardiomyopathy (TTC) remain largely unknown. The aim of this study was therefore to compare the long‐term mortality rate of TTC patients with high‐risk patients presenting with ST‐segment elevation myocardial infarction (STEMI).Methods and resultsA total of 286 patients with TTC were matched for age and gender with 286 STEMI patients. Outcome was obtained with a standardized telephone follow‐up. The primary analysis determined long‐term mortality. A secondary analysis was performed evaluating 28‐day and 1‐year mortality. Follow‐up was available for 96% of patients after a mean of 3.8 ± 2.5 years. In TTC patients, long‐term mortality was significantly higher compared with the matched STEMI cohort [24.7% vs. 15.1%, hazard ratio (HR) 1.58, 95% confidence interval (CI) 1.07–2.33; P = 0.02]. There was no significant difference in the rates of 28‐day (5.5% vs. 5.7%, HR 0.96, 95% CI 0.47–1.94; P = 0.91) and 1‐year mortality (12.5% vs. 9%, HR 1.42, 95% CI 0.85–2.38; P = 0.18). In multivariable regression analysis, male sex, a high Killip class on admission, and diabetes mellitus were identified as independent predictors of mortality in TTC patients. A risk score consisting of these factors showed a higher mortality with an increasing number of risk factors.ConclusionMortality rates in TTC patients are higher than previously expected and long‐term mortality exceeded that of patients with STEMI. A simple risk score may provide an approach to identify high‐risk patients and predict clinical prognosis.
Synthesis, Structure and Chemical Vapour Deposition Studies on the Group 13 Complexes [Me2M­{tfacnac}] [M = Al, Ga, In; Htfacnac = F3CC(OH)CHC(CH3)NCH2CH2OCH3]
Authors: Cosham Samuel D. , Hamilton Jeff A. , Hill Michael S. , Johnson Andrew L. , Molloy Kieran C. 
Published: March 2016

AbstractA family of group 13 metal dimethyl complexes of the general formula [Me2M{MeC(O)CHC(NCH2CH2OMe)CF3}] [M = Al (2), Ga (3) or In (4)] was synthesised by reaction of the isolated free ligand 1 with the corresponding trimethyl metal reagents. The isolated complexes 2–4 were characterised by elemental analysis and NMR spectroscopy, and the molecular structures of the complexes were determined by single‐crystal X‐ray diffraction, which revealed them to be monomeric five‐coordinate complexes with coordination of the pendent ether‐bearing lariat in the solid state. Thermogravimetric analysis showed complexes 2–4 all to have residual masses at 200 °C of 2.4 % or less, well below the value for the respective metal oxides, and vapour pressure measurements showed the indium complex 4 to be an order of magnitude less volatile (0.09 Torr at 80 °C) than the Al (2) and Ga (3) analogues, despite their being isoleptic systems. Complexes 2–4 were investigated for their utility in the low‐pressure metal organic chemical vapour deposition of the respective metal oxides in the absence of additional oxidant at 400 °C on silicon substrates.
Diels–Alder Cycloaddition of Tetraphenylcyclopentadienone and 1,3,5‐Hexatriynes
Authors: Sale Anna Chiara , Murray Adrian H. , Prenzel Dominik , Hampel Frank , De Luca Lidia , Tykwinski Rik R. 
Published: March 2016

AbstractDiels–Alder cycloaddition reactions of 1,3,5‐hexatriynes with tetraphenylcyclopentadienone have been performed, and mainly gave 1,2‐diethynyl‐3,4,5,6‐tetraphenylbenzene derivatives as products. The Diels–Alder reactions were optimized under conventional heating and microwave irradiation conditions, and showed good selectivity towards the central carbon–carbon triple bond of the triyne. Empirical evidence suggests that the selectivity of the reaction is governed predominantly by the steric demands of the end‐groups of the triyne. Several of the Diels–Alder products could be further elaborated by a sequence of desilylation and oxidative homocoupling to provide dimeric products. The homocoupling reaction was optimized by Pd catalysis. The X‐ray crystallographic analysis of two derivatives is reported.
Rare Sesquiterpenoids from the Shed Trunk Barks of the Critically Endangered Plant Abies beshanzuensis and Their Bioactivities
Authors: Hu Chang‐Ling , Xiong Juan , Li Ji‐Yang , Gao Li‐Xin , Wang Wen‐Xuan , Cheng Ke‐Jun , Yang Guo‐Xun , Li Jia , Hu Jin‐Feng 
Published: March 2016

AbstractTwo rare rearranged cuparane‐type sesquiterpenoid C‐10 epimers [beshanzuenones A (1) and B (2)] and two bisabolane‐type sesquiterpenoid spirolactones [beshanzuenones C (3) and D (4)] featuring an unusual [6/6/5]‐fused tricyclic ring system were isolated from the shed trunk barks of Abies beshanzuensis, one of the critically endangered plant species in the world. The structures of these four new enone‐containing sesquiterpenoids were determined by spectroscopic analyses and single‐crystal X‐ray diffraction or electronic circular dichroism (ECD) calculations. Compounds 1 and 2 showed considerable activity against the H3N2 virus, whereas 3 and 4 exhibited significant inhibition on PTP1B.
Shaking table test and numerical simulation of an RC frame‐core tube structure for earthquake‐induced collapse
Authors: Lu Zheng , Chen Xiaoyi , Lu Xilin , Yang Zi 
Published: March 2016

SummaryThe reinforced concrete frame‐core tube structure is a common form of high‐rise building; however, certain vertical components of these structures are prone to be damaged by earthquakes, debris flow, or other accidents, leaving no time for repair or retrofit. This study is motivated by a practical problem—that is, the seismic vulnerability and collapse resistant capability under future earthquakes when a vertical member has failed. A reduced scale model (1:15 scale) of a typical reinforced concrete frame‐core tube with a corner column removed from the first floor is designed, fabricated, and tested. The corner column is replaced by a jack, and the failure behavior is simulated by manually unloading the jack. The model is then excited by a variety of seismic ground motions on the shaking table. Experimental results concerning the seismic responses and actual process of collapse are presented herein. Finally, the earthquake‐induced collapse process is simulated numerically using the software program ANSYS/LS‐DYNA. Validation and calibration of the model are carried out by comparison with the experimental results. Furthermore, based on both experimental investigations and numerical simulations, the collapse mechanism is discussed, and some suggestions on collapse design are put forward. Copyright © 2016 John Wiley & Sons, Ltd.
Denudation rates on cratonic landscapes: comparison between suspended and dissolved fluxes, and 10Be analysis in the Nyong and Sanaga River basins, south Cameroon
Authors: Regard Vincent , Carretier Sébastien , Boeglin Jean‐Loup , Ndam Ngoupayou Jules‐Rémy , Dzana Jean‐Guy , Bedimo Bedimo Jean‐Pierre , Riotte Jean , Braun Jean‐Jacques 
Published: March 2016

AbstractSouth Cameroon is located in a tropical and tectonically quiescent region, with landscapes characterized by thick highly weathered regolith, indicative of the long‐term predominance of chemical weathering over erosion. Currently this region undergoes huge changes due to accelerated mutations related to a growing population and economical developments with associated needs and increasing pressures on land and natural resources. We analysed two of the main south Cameroon rivers: the Nyong River and Sanaga River. The Sanaga catchment undergoes a contrasted tropical climate from sub‐humid mountainous and humid climate and is impacted by deforestation, agriculture, damming, mining and urbanization, especially in the Mbam sub‐basin, draining the highly populated volcanic highlands. By contrast, the Nyong catchment, only under humid tropical climate, is preserved from anthropogenic disturbance with low population except in the region of Yaoundé (Méfou sub‐basin). Moreover the Nyong basin is dam‐free and less impacted by agriculture and logging.We explore both denudation temporal variability and the ratio between chemical and physical denudation through two catchment‐averaged erosion and denudation datasets. The first one consists of an 11‐year long gauging dataset, while the second one comes from cosmogenic radionuclides [CRNs, here beryllium‐10 (10Be)] from sand sampled in the river mainstreams (timescale of tens to hundreds of thousands of years). Modern fluxes estimated from gauging data range from 5 to 100 m/Ma (10 to 200 t/km2/yr); our calculations indicate that the usual relative contribution of chemical versus physical denudation is 60% and 40%, respectively, of the total denudation. Beryllium‐10 denudation rates and sediment fluxes range from 4.8 to 40.3 m/Ma or 13 to 109 t/km2/yr, respectively, after correction for quartz enrichment. These fluxes are slightly less than the modern fluxes observed in Cameroon and other stable tropical areas. The highest 10Be‐derived fluxes and the highest physical versus chemical denudation ratios are attributed to anthropogenic impact. Copyright © 2016 John Wiley & Sons, Ltd.
River sensitivity: a lost foundation concept in fluvial geomorphology
Authors: Fryirs Kirstie A 
Published: March 2016

AbstractIn the twenty‐first century, fluvial geomorphologists are ideally placed to use their science in an applied manner, and provide guidance on environmental issues of concern. Understanding the impact of floods and droughts, land use and climate change, water use, etc. on river forms, processes and evolution requires that we understand interactions between water, sediment and vegetation, and how climate and anthropogenic impacts shape those interactions. More frequently, fluvial geomorphologists are asked to provide answers to a range of river issues, make forecasts about how systems might adjust in the future, and work with managers to implement strategies on‐the‐ground. To some, the field of fluvial geomorphology is underprepared for this task as several principles of landscape form, process and evolution are yet to be fully explored. Others however, see that geomorphologists have a suite of principles and tools at their disposal, and sufficient understanding to make forecasts about future river adjustments with some level of confidence. One concept that has been lost in recent years, but should lie at the heart of such analyses is that of river sensitivity.In this paper I draw on foundation literature to review the concept of river sensitivity. I provide examples that demonstrate how this concept could be reshaped and used for analyses at landform, reach and catchment scales. At the landform scale, morphological sensitivity is a function of textural and geometric sensitivity. At the reach scale, analyses consider inherent behavioural and change sensitivity. At the catchment scale river response and recovery are a function of locational, transmission and filter sensitivity. I then discuss how some temporal concepts can be used to consider how sensitivity in itself adjusts over time. Finally, I discuss future challenges for analysis of river sensitivity and consider how it could be used to improve geomorphological forecasting for use in river management. Copyright © 2016 John Wiley & Sons, Ltd.
Evaluation and hydrological application of precipitation estimates derived from PERSIANN‐CDR, TRMM 3B42V7, and NCEP‐CFSR over humid regions in China
Authors: Zhu Qian , Xuan Weidong , Liu Li , Xu Yue‐Ping 
Published: March 2016

AbstractSatellite‐based and reanalysis quantitative precipitation estimates are attractive for hydrologic prediction or forecasting and reliable water resources management, especially for ungauged regions. This study evaluates three widely used global high‐resolution precipitation products [Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks‐Climate Data Record (PERSIANN‐CDR), Tropical Rainfall Measuring Mission 3B42 Version 7 (TRMM 3B42V7), and National Centers for Environment Prediction‐Climate Forecast System Reanalysis (NCEP‐CFSR)] against gauge observations with seven statistical indices over two humid regions in China. Furthermore, the study investigates whether the three precipitation products can be reliably utilized as inputs in Soil and Water Assessment Tool, a semi‐distributed hydrological model, to simulate streamflows. Results show that the precipitation estimates derived from TRMM 3B42V7 outperform the other two products with the smallest errors and bias, and highest correlation at monthly scale, which is followed by PERSIANN‐CDR and NCEP‐CFSR in this rank. However, the superiority of TRMM 3B42V7 in errors, bias, and correlations is not warranted at daily scale. PERSIANN‐CDR and 3B42V7 present encouraging potential for streamflow prediction at daily and monthly scale respectively over the two humid regions, whilst the performance of NCEP‐CFSR for hydrological applications varies from basin to basin. Simulations forced with 3B42V7 are the best among the three precipitation products in capturing daily measured streamflows, whilst PERSIANN‐CDR‐driven simulations underestimate high streamflows and high streamflow simulations driven by NCEP‐CFSR mostly are overestimated significantly. In terms of extreme events analysis, PERSIANN‐CDR often underestimates the extreme precipitation, so do extreme streamflow simulations forced with it. NCEP‐CFSR performs just the reverse, compared with PERSIANN‐CDR. The performance pattern of TRMM 3B42V7 on extremes is not certain, with coexisting underestimation and overestimation. Copyright © 2016 John Wiley & Sons, Ltd.