bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing parasite ‘intimacy’: the whipworm Trichuris muris in the European house mouse hybrid zone
Authors: Wasimuddin   , Bryja Josef , Ribas Alexis , Baird Stuart J. E. , Piálek Jaroslav , Goüy de Bellocq Joëlle
Published: March 2016

Host‐parasite interaction studies across hybrid zones often focus on host genetic variation, treating parasites as homogeneous. ‘Intimately’ associated hosts and parasites might be expected to show similar patterns of genetic structure. In the literature, factors such as no intermediate host and no free‐living stage have been proposed as ‘intimacy’ factors likely constraining parasites to closely follow the evolutionary history of their hosts. To test whether the whipworm, Trichuris muris, is intimately associated with its house mouse host, we studied its population genetics across the European house mouse hybrid zone (HMHZ) which has a strong central barrier to gene flow between mouse taxa. T. muris has a direct life cycle and nonmobile free stage: if these traits constrain the parasite to an intimate association with its host we expect a geographic break in the parasite genetic structure across the HMHZ. We genotyped 205 worms from 56 localities across the HMHZ and additionally T. muris collected from sympatric woodmice (Apodemus spp.) and allopatric murine species, using mt‐COX1, ITS1‐5.8S‐ITS2 rDNA and 10 microsatellites. We show four haplogroups of mt‐COX1 and three clear ITS1‐5.8S‐ITS2 clades in the HMHZ suggesting a complex demographic/phylogeographic history. Microsatellites show strong structure between groups of localities. However, no marker type shows a break across the HMHZ. Whipworms from Apodemus in the HMHZ cluster, and share mitochondrial haplotypes, with those from house mice. We conclude Trichuris should not be regarded as an ‘intimate’ parasite of the house mouse: while its life history might suggest intimacy, passage through alternate hosts is sufficiently common to erase signal of genetic structure associated with any particular host taxon.
Drought responses of three closely related Caragana species: implication for their vicarious distribution
Authors: Ma Fei , Na Xiaofan , Xu Tingting
Published: March 2016

Drought is a major environmental constraint affecting growth and distribution of plants in the desert region of the Inner Mongolia plateau. Caragana microphylla, C. liouana, and C. korshinskii are phylogenetically close but distribute vicariously in Mongolia plateau. To gain a better understanding of the ecological differentiation between these three species, we examined the leaf gas exchange, growth, water use efficiency, biomass accumulation and allocation by subjecting their seedlings to low and high drought treatments in a glasshouse. Increasing drought stress had a significant effect on many aspects of seedling performance in all species, but the physiology and growth varied with species in response to drought. C. korshinskii exhibited lower sensitivity of photosynthetic rate and growth, lower specific leaf area, higher biomass allocation to roots, higher levels of water use efficiency to drought compared with the other two species. Only minor interspecific differences in growth performances were observed between C. liouana and C. microphylla. These results indicated that faster seedling growth rate and more efficient water use of C. korshinskii should confer increased drought tolerance and facilitate its establishment in more severe drought regions relative to C. liouana and C. microphylla.
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

Whereas 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

Yersinia 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

The 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

Salmonids 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

Aims

Despite 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 results

A 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.

Conclusion

Mortality 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.
Pyridylborates as a New Type of Robust Scorpionate Ligand: From Metal Complexes to Polymeric Materials
Authors: Pawar Gajanan M. , Sheridan John B. , Jäkle Frieder
Published: March 2016

The importance of scorpionate ligands in modern coordination chemistry continues to increase, because of their outstanding versatility, tunability and user‐friendliness. Herein, we provide a short overview of recent developments in the classes of scorpionate ligands, derived from pyrazoles, triazoles, imidazoles, oxazolines, thioimidazoles and other similar systems, followed by an in‐depth discussion of a new type of robust and tunable scorpionate ligand, tris(2‐pyridyl)borates. The structure and synthesis of tris(2‐pyridyl)borate (Tpyb) ligands are discussed, and key features of coordination of Tpyb ligands with metal ions, as well as supramolecular crystal packing, transmetallation and applications in metallo‐supramolecular polymer chemistry are addressed.
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

A 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

Diels–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

Two 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.
Food peptidomics of in vitro gastrointestinal digestions of partially purified bovine hemoglobin: low‐resolution versus high‐resolution LC‐MS/MS analyses
Authors: Caron Juliette , Chataigné Gabrielle , Gimeno Jean‐Pascal , Duhal Nathalie , Goossens Jean‐François , Dhulster Pascal , Cudennec Benoit , Ravallec Rozenn , Flahaut Christophe
Published: March 2016

Consumers and governments have become aware how the daily diet may affect the human health. All proteins from both plant and animal origins are potential sources of a wide range of bioactive peptides and the large majority of those display health‐promoting effects. In the meat production food chain, the slaughterhouse blood is an inevitable co‐product and, today, the blood proteins remain underexploited despite their bioactive potentiality. Through a comparative food peptidomics approach we illustrate the impact of resolving power, accuracy, sensitivity, and acquisition speed of low‐resolution (LR)‐ and high‐resolution (HR)‐LC‐ESI‐MS/MS on the obtained peptide mappings and discuss the limitations of MS‐based peptidomics. From in vitro gastrointestinal digestions of partially purified bovine hemoglobin, we have established the peptide maps of each hemoglobin chain. LR technique (normal bore C18 LC‐LR‐ESI‐MS/MS) allows us to identify without ambiguity 75 unique peptides while the HR approach (nano bore C18 LC‐HR‐ESI‐MS/MS) unambiguously identify more than 950 unique peptides (post‐translational modifications included). Herein, the food peptidomics approach using the most performant separation methods and mass spectrometers with high‐resolution capabilities appears as a promising source of information to assess the health potentiality of proteins.
Development and validation of a method to determine thiabendazole and o‐phenylphenol in wastewater using micellar liquid chromatography‐fluorescence detection
Authors: Peris‐Vicente Juan , Roca‐Genovés Pasqual , Tayeb‐Cherif Khaled , Esteve‐Romero Josep
Published: March 2016

A micellar liquid chromatographic method to determine thiabendazole (TBZ) and o‐phenylphenol in wastewater is described here. The sample was directly injected without any additional treatment other filtration. The pesticides were resolved in <11 min, using a mobile phase of 0.10 M SDS—6% 1‐pentanol buffered at pH 3 running through a C18 column at 1 mL/min. The detection was performed by fluorescence at 305/360 and 245/345 nm excitation/emission wavelengths for TBZ and o‐phenylphenol, respectively. The method was validated following the directives of the Validation and Peer Review of U.S. Environmental Protection Agency Chemical Methods of Analysis guidelines in terms of selectivity, quantitation range (0.01–0.02 to 2 mg/L), detection limit (0.005–0.008 mg/L), trueness (92.1–104.2%), precision (<13.9%), robustness (<6.6%), and stability under storage conditions. The procedure was applied to the screening of TBZ and o‐phenylphenol in wastewater samples from citrus packing plants, agricultural gutters, urban sewage, as well as in influent and effluent wastewater treatment plants.
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

The 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

South 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

In 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.
Suppression of lethal‐7b and miR‐125a/b Maturation by Lin28b Enables Maintenance of Stem Cell Properties in Hepatoblasts
Authors: Takashima Yasuo , Terada Maiko , Udono Miyako , Miura Shizuka , Yamamoto Junpei , Suzuki Atsushi
Published: March 2016

In liver development, hepatoblasts that act as hepatic stem/progenitor cells proliferate and differentiate into both hepatocytes and cholangiocytes to form liver tissues. Although numerous factors contribute to this event, little is known about the roles of microRNAs in hepatoblast proliferation and differentiation. In this study, we focused on the lineage‐28 (Lin28) family proteins, which are required for microRNA regulation in pluripotent stem cells and cancer cells, and investigated their roles as regulatory factors for the properties of hepatoblasts. Conclusion: Lin28b was specifically expressed in hepatoblasts, and its suppression induced growth arrest and cholangiocyte differentiation of hepatoblasts; mechanistically, Lin28b positively regulates the expression of Lin28b itself and cell cycle–related proteins in hepatoblasts by suppressing the maturation of target microRNAs, lethal‐7b and miR‐125a/b, enabling maintenance of the stem cell properties of hepatoblasts, such as their capabilities for proliferation and bi‐lineage differentiation, during liver development. (Hepatology 2016;64:245–260)
Early outpatient follow‐up and 30‐day outcomes in patients hospitalized with cirrhosis
Authors: Kanwal Fasiha , Asch Steven M. , Kramer Jennifer R. , Cao Yumei , Asrani Sumeet , El‐Serag Hashem B.
Published: March 2016

Preventing readmission has been the focus of numerous quality improvement efforts across many conditions. Early outpatient follow‐up has been proposed as the best mechanism for reducing readmissions. The extent to which early outpatient follow‐up averts readmission or improves outcomes in cirrhosis is not known. We evaluated the relationship between early outpatient follow‐up and short‐term readmission and mortality in patients with cirrhosis. We conducted a retrospective cohort study of patients with cirrhosis who were hospitalized with a liver‐related diagnosis and discharged to home from 122 Veterans Administration hospitals between 2010 and 2013. We defined early follow‐up as an outpatient visit with a clinician within 7 days after discharge. We propensity matched patients who received early visit with those who did not have any visit and examined the associations between early follow‐up and all‐cause readmission and mortality within 8‐30 days after discharge. Of 25,217 patients hospitalized with cirrhosis, 8,123 (32.2%) had an early follow‐up visit within 7 days of discharge. A total of 3,492 (13.8%) patients were readmitted and 1,185 (4.6%) died between 8 and 30 days after discharge. In the propensity‐matched sample (N = 16,238), patients with early outpatient follow‐up visit had a slightly higher risk of readmission (15.3% vs. 13.8%; hazard ratio [HR] =1.10; 95% confidence interval [CI] = 1.02‐1.19), but significantly lower risk of mortality (3.2% vs. 5.2%; HR = 0.60; 95% CI = 0.51‐0.70) than those without early visit. The findings persisted in several subgroup and sensitivity analyses. Conclusions: Early outpatient follow‐up after discharge was associated with a small increase in readmissions but lower overall mortality in patients with cirrhosis. Transitional care may be effective in improving short‐term outcomes in patients with cirrhosis, but readmission performance measures would miss this effect. (Hepatology 2016;64:569‐581)
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

Satellite‐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.
Changing river temperatures in northern Germany: trends and drivers of change
Authors: Arora Roshni , Tockner Klement , Venohr Markus
Published: March 2016

Climate change is one of the main drivers of river warming worldwide. However, the response of river temperature to climate change differs with the hydrology and landscape properties, making it difficult to generalize the strength and the direction, of river temperature trends across large spatial scales and various river types. Additionally, there is a lack of long‐term and large‐scale trend studies in Europe as well as globally. In this study, we investigated the long‐term (25 years; 132 sites) and the short‐term (10 years; 475 sites) river temperature trends, patterns and underlying drivers within the period 1985–2010 in seven river basins of Germany. The majority of the sites underwent significant river warming during 1985–2010 (mean warming trend: 0.03 °C year−1, SE = 0.003), with a faster warming observed during individual decades (1985–1995 and 2000–2010) within this period. Seasonal analyses showed that, while rivers warmed in all seasons, the fastest warming had occurred during summer. Among all the considered hydro‐climatological variables, air temperature change, which is a response to climate forcing, was the main driver of river temperature change because it had the strongest correlation with river temperature, irrespective of the period. Hydrological variables, such as average flow and baseflow, had a considerable influence on river temperature variability rather than on the overall trend direction. However, decreasing flow probably assisted in a faster river temperature increase in summer and in rivers in NE basins (such as the Elbe basin). The North Atlantic Oscillation Index had a greater significant influence on the winter river temperature variability than on the overall variability. Landscape and basin variables, such as altitude, ecoregion and catchment area, induced spatially variable river temperature trends via affecting the thermal sensitivity of rivers, with the rivers in large catchments and in lowland areas being most sensitive. Copyright © 2016 John Wiley & Sons, Ltd.
Emergent verbal behavior in preschool children learning a second language
Authors: May Richard J. , Downs Rachel , Marchant Amanda , Dymond Simon
Published: March 2016

We evaluated the emergence of untaught second‐language skills following directly taught listener and intraverbal responses. Three preschool children were taught first‐language (English) listener responses (e.g., “Point to the horse”) and second‐language (Welsh) intraverbal responses (e.g., “What is horse in Welsh?” [ceffyl]). After intervention, increases in untaught second‐language tacts (e.g., “What is this in Welsh?” [ceffyl]) and listener responses (e.g., “Point to the ceffyl”) were observed for all 3 participants.
Forecasting Tail Risks
Authors: De Nicolò Gianni , Lucchetta Marcella
Published: March 2016

This paper presents an early warning system as a set of multi‐period forecasts of indicators of tail real and financial risks obtained using a large database of monthly US data for the period 1972:1–2014:12. Pseudo‐real‐time forecasts are generated from: (a) sets of autoregressive and factor‐augmented vector autoregressions (VARs), and (b) sets of autoregressive and factor‐augmented quantile projections. Our key finding is that forecasts obtained with AR and factor‐augmented VAR forecasts significantly underestimate tail risks, while quantile projections deliver fairly accurate forecasts and reliable early warning signals for tail real and financial risks up to a 1‐year horizon. Copyright © 2016 John Wiley & Sons, Ltd.
Let‐7a modulates particulate matter (≤ 2.5 μm)‐induced oxidative stress and injury in human airway epithelial cells by targeting arginase 2
Authors: Song Lei , Li Dan , Gu Yue , Li Xiaoping , Peng Liping
Published: March 2016

Epidemiological studies show that particulate matter (PM) with an aerodynamic diameter ≤ 2.5 μm (PM2.5) is associated with cardiorespiratory diseases via the induction of excessive oxidative stress. However, the precise mechanism underlying PM2.5‐mediated oxidative stress injury has not been fully elucidated. Accumulating evidence has indicated the microRNA let‐7 family might play a role in PM‐mediated pathological processes. In this study, we investigated the role of let‐7a in oxidative stress and cell injury in human bronchial epithelial BEAS2B (B2B) cells after PM2.5 exposure. The let‐7a level was the most significantly decreased in B2B cells after PM2.5 exposure. The overexpression of let‐7a suppressed intracellular reactive oxygen species levels and the percentage of apoptotic cells after PM2.5 exposure, while the let‐7a level decreased arginase 2 (ARG2) mRNA and protein levels in B2B cells by directly targeting the ARG2 3′‐untranslated region. ARG2 expression was upregulated in B2B cells during PM2.5 treatment, and ARG2 knockdown could remarkably reduce oxidative stress and cellular injury. Moreover, its restoration could abrogate the protective effects of let‐7a against PM2.5‐induced injury. In conclusion, let‐7a decreases and ARG2 increases resulting from PM2.5 exposure may exacerbate oxidative stress, cell injury and apoptosis of B2B cells. The let‐7a/ARG2 axis is a likely therapeutic target for PM2.5‐induced airway epithelial injury. Copyright © 2016 John Wiley & Sons, Ltd.
Nanoporous metals for biodegradable implants: Initial bone mesenchymal stem cell adhesion and degradation behavior
Authors: Heiden Michael , Huang Sabrina , Nauman Eric , Johnson David , Stanciu Lia
Published: March 2016

Nanostructured Fe‐Mn and Fe‐Mn‐Zn metal scaffolds were generated through a well‐controlled selective leaching process in order to fulfill the growing demand for adjustable degradation rates and improved cellular response of resorbable materials. Mouse bone marrow mesenchymal stem cells (D1 ORL UVA) were seeded onto eleven, carefully chosen nanoporous surfaces for 24 hin vitro. Using a combination of fluorescence microscopy, scanning electron microscopy (SEM), and an MTS assay, it was discovered that scaffolds with nanoscale roughened surfaces had increased cell attachment by up to 123% compared to polished smooth Fe‐Mn surfaces. Significant cell spreading and construction of cell multilayers were also apparent after 24 h, suggesting better adhesion. Additionally, static electrochemical polarization experiments revealed an improvement of up to 26% in the actual rate of biodegradation for Fe‐Mn surface‐modified materials. However, any residual concentration of zinc after leaching was shown to slightly increase corrosion resistance. The results demonstrate that selectively leached, nanostructured Fe‐Mn surfaces have the potential of being tailored to a diverse set of transient implant scenarios, while also effectively boosting overall biocompatibility, initial cell attachment, and degradation rate. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1747–1758, 2016.
Comparison of clinical explants and accelerated hydrolytic aging to improve biostability assessment of silicone‐based polyurethanes
Authors: Cosgriff‐Hernandez Elizabeth , Tkatchouk Ekaterina , Touchet Tyler , Sears Nick , Kishan Alysha , Jenney Christopher , Padsalgikar Ajay D. , Chen Emily
Published: March 2016

Although silicone‐based polyurethanes have demonstrated increased oxidative stability, there have been conflicting reports of the long‐term hydrolytic stability of Optim™ and PurSil® 35 based on recent temperature‐accelerated hydrolysis studies. The goal of the current study was to identify in vitro–in vivo correlations to determine the relevance of this accelerated in vitro model for predicting clinical outcomes. Temperature‐accelerated hydrolytic aging of three commonly used cardiac lead insulation materials, Optim™, Elasthane™ 55D, Elasthane™ 80A, and a related silicone‐polyurethane, PurSil® 35, was performed. After 1 year at 85°C, similar losses in Mn and Mz were observed for the poly(ether urethanes), but an increase in Mz loss as compared to Mn loss was observed for the silicone‐based polyurethanes. A similar trend of increased Mz loss as compared to Mn loss was observed in explanted Optim™ leads after 2–3 years; however, no statistically significant Mn loss was detected between 2–3 and 7–8 years of implantation. Given this preferential loss of high molecular weight chains, it was hypothesized that the observed differences between the polyurethanes were due to allophanate dissociation rather than backbone chain scission. Following full dissociation of the small percentage of allophanates in vivo, the observed molecular weight stability and proven clinical performance of Optim™ was attributed to the well‐documented stability of the urethane bond under physiological conditions. This allophanate dissociation reaction is incompatible with the first order mechanism proposed in previous temperature‐accelerated hydrolysis studies and may be the reason for the model's inaccurate prediction of significant and progressive molecular weight loss in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1805–1816, 2016.
Effects of electromagnetic field frequencies on chondrocytes in 3D cell‐printed composite constructs
Authors: Yi Hee‐Gyeong , Kang Kyung Shin , Hong Jung Min , Jang Jinah , Park Moon Nyeo , Jeong Young Hun , Cho Dong‐Woo
Published: March 2016

In cartilage tissue engineering, electromagnetic field (EMF) therapy has been reported to have a modest effect on promoting cartilage regeneration. However, these studies were conducted using different frequencies of EMF to stimulate chondrocytes. Thus, it is necessary to investigate the effect of EMF frequency on cartilage formation. In addition to the stimulation, a scaffold is required to satisfy the characteristics of cartilage such as its hydrated and dense extracellular matrix, and a mechanical resilience to applied loads. Therefore, we 3D‐printed a composite construct composed of a polymeric framework and a chondrocyte‐laden hydrogel. Here, we observed frequency‐dependent positive and negative effects on chondrogenesis using a 3D cell‐printed cartilage tissue. We found that a frequency of 45 Hz promoted gene expression and secretion of extracellular matrix molecules of chondrocytes. In contrast, a frequency of 7.5 Hz suppressed chondrogenic differentiation in vitro. Additionally, the EMF‐treated composite constructs prior to implantation showed consistent results with those of in vitro, suggesting that in vitro pre‐treatment with different EMF frequencies provides different capabilities for the enhancement of cartilage formation in vivo. This correlation between EMF frequency and 3D‐printed chondrocytes suggests the necessity for optimization of EMF parameters when this physical stimulus is applied to engineered cartilage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1797–1804, 2016.
Nitrate Medications, Fractures, and Change in Bone Mineral Density in Postmenopausal Women: Results from the Women's Health Initiative
Authors: Golchin Negar , Hohensee Chancellor , LaCroix Andrea , Gray Shelly L
Published: March 2016

Nitrate medications may increase bone mineral density (BMD), although information on fracture outcomes is sparse. We examined the association of nitrate medications with fractures (hip, wrist/arm, and total fractures) and changes in BMD (hip, spine, and whole body) in the Women's Health Initiative (WHI) Clinical Trials and Observational Study. A total of 139,211 postmenopausal women 50 to 79 years old without history of hip fracture were included in this prospective study. Medication use was ascertained directly from drug containers at baseline during in-person interviews in 1993 to 1998. Exposure measures included any use (use/non-use), type of nitrate (as-needed, maintenance) and duration of use (≤5 years, >5 years). We used separate multivariable Cox proportional hazard models to analyze associations between each exposure and fracture outcome, with results presented as hazard ratios (HRs) and 95% confidence intervals (CIs). Multivariable linear regression models were used to examine 3-year and 6-year changes in BMD. At baseline, 1.2% (n = 1647) women were using a nitrate. During the mean ± SD follow-up of 7.7 ± 1.5 years through 2005, women experienced 1582 hip fractures, 5156 wrist or arm fractures, and 22, 589 total fractures. After adjustment for confounders, nitrate use was not statistically associated with risk for hip (HR, 0.81; 95% CI, 0.56 to 1.18), wrist/arm (HR, 0.95; 95% CI, 0.74 to 1.23), or total fractures (HR, 0.96; 95% CI, 0.85 to 1.08). As-needed nitrate use, but not maintenance therapy, was associated with a lower risk of total fractures (HR, 0.77; 95% CI, 0.62 to 0.95) and wrist/arm fractures (HR, 0.57; 95% CI, 0.34 to 0.98). Nitrate use was not associated with 3-year or 6-year changes in BMD at any site. We conclude that any nitrate use was not significantly associated with lower risk of fractures or higher BMD; however, as-needed nitrate use was associated with lower risks of total and wrist/arm fractures. © 2016 American Society for Bone and Mineral Research.
γ‐Secretase Dependent Nuclear Targeting of Dystroglycan
Authors: Leocadio Daniel , Mitchell Andrew , Winder Steve J.
Published: March 2016

Dystroglycan is frequently lost in adenocarcinoma. α‐dystroglycan is known to become hypoglycosylated due to transcriptional silencing of LARGE, whereas β‐dystroglycan is proteolytically cleaved and degraded. The mechanism and proteases involved in the cleavage events affecting β‐dystroglycan are poorly understood. Using LNCaP prostate cancer cells as a model system, we have investigated proteases and tyrosine phosphorylation affecting β‐dystroglycan proteolysis and nuclear targeting. Cell density or phorbol ester treatment increases dystroglycan proteolysis, whereas furin or γ‐secretase inhibitors decreased dystroglycan proteolysis. Using resveratrol treatment of LNCaP cells cultured at low cell density in order to up‐regulate notch and activate proteolysis, we identified significant increases in the levels of a 26 kDa β‐dystroglycan fragment. These data, therefore, support a cell density‐dependent γ‐secretase and furin mediated proteolysis of β‐dystroglycan, which could be notch stimulated, leading to nuclear targeting and subsequent degradation. 117: 2149–2157, 2016. © 2016 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.