bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna
Authors: Dohn Justin , Augustine David J. , Hanan Niall P. , Ratnam Jayashree , Sankaran Mahesh 
Published: November 2016

AbstractThe majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation. Interactions among woody plants in savannas are relatively poorly understood. We present data from a 10‐yr longitudinal study of spatially explicit growth patterns of woody vegetation in an East African savanna following exclusion of large herbivores and in the absence of fire. We examined plant spatial patterns and quantified the degree of competition among woody individuals. Woody plants in this semiarid savanna exhibit strongly clumped spatial distributions at scales of 1–5 m. However, analysis of woody plant growth rates relative to their conspecific and heterospecific neighbors revealed evidence for strong competitive interactions at neighborhood scales of up to 5 m for most woody plant species. Thus, woody plants were aggregated in clumps despite significantly decreased growth rates in close proximity to neighbors, indicating that the spatial distribution of woody plants in this region depends on dispersal and establishment processes rather than on competitive, density‐dependent mortality. However, our documentation of suppressive effects of woody plants on neighbors also suggests a potentially important role for tree‐tree competition in controlling vegetation structure and indicates that the balanced‐competition hypothesis may contribute to well‐known patterns in maximum tree cover across rainfall gradients in Africa.
Estimates of local biodiversity change over time stand up to scrutiny
Authors: Vellend Mark , Dornelas Maria , Baeten Lander , Beauséjour Robin , Brown Carissa D. , De Frenne Pieter , Elmendorf Sarah C. , Gotelli Nicholas J. , Moyes Faye , Myers‐Smith Isla H. , Magurran Anne E. , McGill Brian J. , Shimadzu Hideyasu , Sievers Caya 
Published: November 2016

AbstractWe present new data and analyses revealing fundamental flaws in a critique of two recent meta‐analyses of local‐scale temporal biodiversity change. First, the conclusion that short‐term time series lead to biased estimates of long‐term change was based on two errors in the simulations used to support it. Second, the conclusion of negative relationships between temporal biodiversity change and study duration was entirely dependent on unrealistic model assumptions, the use of a subset of data, and inclusion of one outlier data point in one study. Third, the finding of a decline in local biodiversity, after eliminating post‐disturbance studies, is not robust to alternative analyses on the original data set, and is absent in a larger, updated data set. Finally, the undebatable point, noted in both original papers, that studies in the ecological literature are geographically biased, was used to cast doubt on the conclusion that, outside of areas converted to croplands or asphalt, the distribution of biodiversity trends is centered approximately on zero. Future studies may modify conclusions, but at present, alternative conclusions based on the geographic‐bias argument rely on speculation. In sum, the critique raises points of uncertainty typical of all ecological studies, but does not provide an evidence‐based alternative interpretation.
“Hummingbird” floral traits interact synergistically to discourage visitation by bumble bee foragers
Authors: Gegear Robert J. , Burns Rebecca , Swoboda‐Bhattarai Katharine A. 
Published: November 2016

AbstractPollination syndromes are suites of floral traits presumed to reflect adaptations to attract and utilize a “primary” type of animal pollinator. However, syndrome traits may also function to deter “secondary” flower visitors that reduce plant fitness through their foraging activities. Here we use the hummingbird‐pollinated plant species Mimulus cardinalis as a model to investigate the potential deterrent effects of classic bird syndrome traits on bumble bee foragers. To establish that M. cardinalis flowers elicit an avoidance response in bees, we assessed the choice behavior of individual foragers on a mixed experimental array of M. cardinalis and its bee‐pollinated sister species M. lewisii. As expected, bees showed a strong preference against M. cardinalis flowers (only 22% of total bee visits were to M. cardinalis), but surprisingly also showed a high degree of individual specialization (95.2% of total plant transitions were between conspecifics). To determine M. cardinalis floral traits that discourage bee visitation, we then assessed foraging responses of individuals to M. cardinalis‐like and M. lewisii‐like floral models differing in color, orientation, reward, and combinations thereof. Across experiments, M. cardinalis‐like trait combinations consistently produced a higher degree of flower avoidance behavior and individual specialization than expected based on bee responses to each trait in isolation. We then conducted a series of flower discrimination experiments to assess the ability of bees to utilize traits and trait combinations associated with each species. Relative to M. lewisii‐like alternatives, M. cardinalis‐like traits alone had a minimal effect on bee foraging proficiency but together increased the time bees spent searching for rewarding flowers from 1.49 to 2.65 s per visit. Collectively, our results show that M. cardinalis flowers impose foraging costs on bumble bees sufficient to discourage visitation and remarkably, generate such costs through synergistic color‐orientation and color‐reward trait interactions. Floral syndromes therefore represent complex adaptations to multiple pollinator groups, rather than simply the primary pollinator.
Woody plant richness does not influence invertebrate community reassembly trajectories in a tree diversity experiment
Authors: Yeeles Peter , Lach Lori , Hobbs Richard J. , van Wees Mary , Didham Raphael K. 
Published: November 2016

AbstractUnderstanding the relationship between plant diversity and diversity at higher trophic levels is important from both conservation and restoration perspectives. Although there is strong evidence for bottom‐up maintenance of biodiversity, this is based largely on studies of simplified grassland systems. Recently, studies in the TreeDivNet global network of tree diversity experiments have begun to test whether these findings are generalizable to more complex ecosystems, such as woodlands. We monitored invertebrate community reassembly over 5 yr of experimental woodland restoration at the TreeDivNet Ridgefield site in southwest Australia, testing the effects of woody plant species richness and herb‐layer manipulation on invertebrate community structure and ant species composition. From 2010 to 2014, we sampled ground‐dwelling invertebrates using pitfall traps in herbicide vs. no‐herbicide subplots nested within each of 10 woody plant treatments varying in richness from zero (bare controls) to eight species, which produced a total of 211, 235 invertebrates, including 98, 979 ants belonging to 74 species. In mixed model analyses, the presence of woody plants was an important driver of faunal community reassembly (relative to bare control plots), but faunal responses to woody plant treatment combinations were idiosyncratic and unrelated to woody plant richness across treatments. We also found that a herbicide‐induced reduction in herbaceous plant cover and richness had a positive effect on ant richness and caused more rapid convergence of invertebrate community composition toward the composition of a woodland reference site. These findings show that woody plant richness did not have direct positive effects on the diversity and community reassembly trajectories of higher trophic levels in our woodland system. From a management perspective, this suggests that even low‐diversity restoration or carbon sequestration plantings can potentially lead to faunal reassembly outcomes that are comparable to more complex re‐planting designs.
Derivation of Kinetics and Design Parameters for a Carbonator Reactor in a Greenhouse Calcium Looping Process
Authors: Ramezani Mohammad , Tremain Priscilla , Shah Kalpit , Doroodchi Elham , Moghtaderi Behdad 
Published: November 2016

AbstractThe carbonation/calcination reaction cycle of a limestone sorbent was studied experimentally by using a thermogravimetric analyzer for unique conditions, such as low temperature (400 to 500 °C) and low CO2 partial pressure (0.05 to 0.1 %), pertinent to a novel greenhouse calcium looping process. The kinetic parameters were obtained and compared with those reported in the literature. Various gas–solid reaction mechanisms were considered to determine the best reaction mechanism for the carbonation reaction. The diffusion function, or G(x)=x2, had the best least‐squares linear fit, which resulted in a first‐order reaction for the carbonation reaction in the greenhouse calcium looping process. Moreover, the activation energy and pre‐exponential factor of the carbonation reaction were established to be 19.7 kJ mol−1 and 295.8 min−1 kPa−1, respectively. The derived kinetic parameters were used in Aspen Plus to optimize the carbonator reactor size. The required size of the reactor decreased with increasing operating temperature of the reactor. Exergy analysis revealed that the overall exergetic efficiency of greenhouse calcium looping could be more than 80 %.
Platinum Nanoparticles Supported on TiO2 Photonic Crystals as Highly Active Photocatalyst for the Reduction of CO2 in the Presence of Water
Authors: Jiao Jinqing , Wei Yuechang , Chi Kebin , Zhao Zhen , Duan Aijun , Liu Jian , Jiang Guiyuan , Wang Yajun , Wang Xilong , Han Changcun , Zheng Peng 
Published: November 2016

AbstractPhotonic crystals can delay the propagation of light and increase its path length through a slow‐light effect, which could have immense potential in improving photocatalytic conversion efficiencies. We employed a colloidal crystal template method to synthesize TiO2 photonic crystals (PC‐TiO2), with platinum nanoparticles (Pt NPs) being deposited on the surface of the PC‐TiO2 support at different loading amounts by the gas bubbling‐assisted membrane reduction (GBMR) method. A series of Pt/PC‐TiO2 photocatalysts with well‐defined inverse‐opal structure have uniform Pt NPs (about 2.5 nm) homogeneously dispersed on the pore walls of the support. The slow‐light effect of photonic crystals effectively enhances the absorption efficiency of solar irradiation. Moreover, the Pt deposition significantly extends the spectral response and reduces the recombination rates of photoinduced electron–hole pairs. As a result, the Ptx/PC‐TiO2 catalysts exhibit excellent photocatalytic activity for the reduction of CO2 in the presence of H2O. In addition, we propose a reaction mechanism for the photoreduction of CO2 under light irradiation.
The elements and richness of particle diffusion during sediment transport at small timescales
Authors: Furbish David Jon , Fathel Siobhan L. , Schmeeckle Mark W. , Jerolmack Douglas J. , Schumer Rina 
Published: November 2016

AbstractThe ideas of advection and diffusion of sediment particles are probabilistic constructs that emerge when the Master equation, a precise, probabilistic description of particle conservation, is approximated as a Fokker–Planck equation. The diffusive term approximates nonlocal transport. It ‘looks’ upstream and downstream for variations in particle activity and velocities, whose effects modify the advective term. High‐resolution measurements of bedload particle motions indicate that the mean squared displacement of tracer particles, when treated as a virtual plume, primarily reflects a nonlinear increase in the variance in hop distances with increasing travel time, manifest as apparent anomalous diffusion. In contrast, an ensemble calculation of the mean squared displacement involving paired coordinate positions independent of starting time indicates a transition from correlated random walks to normal (Fickian) diffusion. This normal behavior also is reflected in the particle velocity autocorrelation function. Spatial variations in particle entrainment produce a flux from sites of high entrainment toward sites of low entrainment. In the case of rain splash transport, this leads to topographic roughening, where differential rain splash beneath the canopy of a desert shrub contributes to the growth of a soil mound beneath the shrub. With uniform entrainment, rain splash transport, often described as a diffusive process, actually represents an advective particle flux that is proportional to the land surface slope. Particle diffusion during both bedload and rain splash transport involves motions that mostly are patchy, intermittent and rarefied. The probabilistic framework of the Master equation reveals that continuous formulations of the flux and its divergence (the Exner equation) represent statistically expected behavior, analogous to Reynolds‐averaged conditions. Key topics meriting clarification include the mechanical basis of particle diffusion, effects of rarefied conditions involving patchy, intermittent motions, and effects of rest times on diffusion of tracer particles and particle‐borne substances. Copyright © 2016 John Wiley & Sons, Ltd.
Using a landform evolution model to study ephemeral gullying in agricultural fields: the effects of rainfall patterns on ephemeral gully dynamics
Authors: Hoober David , Svoray Tal , Cohen Sagy 
Published: November 2016

AbstractWater driven soil erosion is a major cause of land degradation worldwide. Ephemeral gullies (EGs) are considered key contributors to agricultural catchment soil loss. Despite their importance, the parameters and drivers controlling EG dynamics have not been adequately quantified. Here we investigate the effects of rainfall characteristics on EGs, using the physically based landform evolution model (LEM) CAESAR‐Lisflood. An initial goal of this study was to test the feasibility of using a LEM to estimate EG dynamics based on an easily obtainable and moderate spatial resolution (2 × 2 m) Digital Elevation Model (DEM). EG evolution was simulated for two rainfall seasons in a 0.37 km2 agricultural plot situated in a semiarid catchment in central Israel. The 2014 rainfall season was used to calibrate the model and the 2015 season was used for validation. The model overall well predicted the EG network structure and average depth but tended to underestimate the EG length. The effects of rainfall characteristics on EG dynamics were investigated by comparing simulations employing seven rainfall scenarios. Four of these scenarios differ in their overall rainfall volume relative to observed precipitation (+20%, +10%, −10%, −20%). The remaining three scenarios vary in the temporal distribution of rainfall during each storm, allowing us to isolate the effect of rainfall intensity on EG evolution. The results show that: (1) EG dynamics strongly correlated with changes in rainfall volume; (2) small‐scale morphological behavior varies between rainfall scenarios, resulting in different meandering and connectivity variability; (3) EG evolution is divided into two main stages, an initial rapid development occurring after the first two weeks of the rainy season, followed by a stable development period; (4) a 12 mm h−1 intensity threshold was observed to initiate and, later, modify EGs; and (5) inner storm rainfall variability can have a considerable effect on EG evolution. Copyright © 2016 John Wiley & Sons, Ltd.
Surface water quality in a sulfide mineral‐rich arid zone in North‐Central Chile: Learning from a complex past, addressing an uncertain future
Authors: Flores Mauricio , Núñez Jorge , Oyarzún Jorge , Freixas Gustavo , Maturana Hugo , Oyarzún Ricardo 
Published: November 2016

AbstractThis study presents an analysis of up to 30 years of hydrological variables and selected water quality parameters (pH, SO4, Fe, Cu, and As) in the upper area of the Elqui River basin in North‐Central Chile. A correlation analysis determined statistically significant positive relationship for SO4‐Cu, Fe‐As, and Fe‐Cu. In terms of historical behaviour, no statistically significant trends were detected for precipitation or temperature. In contrast, for flow, there is an overall decreasing pattern for the entire area of study, although only in one case this trend was statistically significant. Along with the aforementioned analysis, a characterization of the flow‐water quality relationships is considered for the time period analyzed. Although erratic behaviours were confirmed, a negative (i.e., inverse) flow‐concentration relationship was identified for SO4, a positive (i.e., direct) relationship for Fe, and undefined relationships for As and Cu were obtained. From these analyses and based on previous studies on projections regarding climate change for the Andean region, and in particular for the upper Elqui zone, an estimation of the possible effects of the change in water regimes on water quality in the area of study is developed. It is likely that a decrease in surface flow, as a consequence of climate change could translate into improvements in water quality in terms of Fe and eventually As and Cu, but into an impairment in the case of SO4. In any case, this is a complex situation that demands special attention in the face of industrial activities that could be developed in tributaries like the Claro River, which currently play an important role in depurating or diluting contaminants in the waters of the Elqui River. Finally, it should be noted that this study addresses an issue that goes beyond the local interest and could be used as a reference to compare other transitional environments containing sulphide ores or areas of hydrothermal alterations, which are considered to be highly vulnerable to climate change and variability.
Goal-Directed Treatment for Osteoporosis: A Progress Report From the ASBMR-NOF Working Group on Goal-Directed Treatment for Osteoporosis
Authors: Cummings Steven R , Cosman Felicia , Lewiecki E Michael , Schousboe John T , Bauer Douglas C , Black Dennis M , Brown Thomas D , Cheung Angela M , Cody Kathleen , Cooper Cyrus , Diez-Perez Adolfo , Eastell Richard , Hadji Peyman , Hosoi Takayuki , Jan De Beur Suzanne , Kagan Risa , Kiel Douglas P , Reid Ian R , Solomon Daniel H , Randall Susan 
Published: November 2016

ABSTRACT
The American Society for Bone and Mineral Research and the United States National Osteoporosis Foundation (NOF) formed a working group to develop principles of goal-directed treatment and identify gaps that need to be filled to implement this approach. With goal-directed treatment, a treatment goal would first be established and choice of treatment determined by the probability of achieving that goal. Goals of treatment would be freedom from fracture, a T-score &gt; –2.5, which is above the NOF threshold for initiating treatment, or achievement of an estimated risk level below the threshold for initiating treatment. Progress toward reaching the patient's goal would be periodically and systematically assessed by estimating the patient's compliance with treatment, reviewing fracture history, repeating vertebral imaging when indicated, and repeating measurement of bone mineral density (BMD). Using these data, a decision would be made to stop, continue, or change therapy. Some of these approaches can now be applied to clinical practice. However, the application of goal-directed treatment cannot be fully achieved until medications are available that provide greater increases in BMD and greater reduction in fracture risk than those that are currently approved; only then can patients with very high fracture risk and very low BMD achieve such goals. Furthermore, assessing future fracture risk in patients on treatment requires a new assessment tool that accurately captures the change in fracture risk associated with treatment and should also be sensitive to the importance of recent fractures as predictors of imminent fracture risk. Lastly, evidence is needed to confirm that selecting and switching treatments to achieve goals reduces fracture risk more effectively than current standard care. © 2016 American Society for Bone and Mineral Research.
Abstract
The fundamental principle of treat-to-goal for osteoporosis is that treatment should be selected according to having a high likelihood of achieving an acceptable level of fracture risk. This is different than but complementary to the current paradigm of monitoring for response to therapy, usually with bone density testing by DXA or bone turnover markers. A patient may respond to therapy yet continue to have an unacceptably high fracture risk. Response to treatment is essential but not necessarily sufficient in achieving an acceptable level of fracture risk.
N‐Glycosylation at Asn 402 Stabilizes N‐Cadherin and Promotes Cell–Cell Adhesion of Glioma Cells
Authors: Xu Yaolin , Chang Ruiqi , Xu Fulin , Gao Yan , Yang Fuming , Wang Can , Xiao Jin , Su Zuopeng , Bi Yongyan , Wang Liying , Zha Xiliang 
Published: November 2016

ABSTRACTCadherin is crucial for cell–cell adhesion and N‐glycosylation of N‐cadherin has been implicated in the process of mammary, renal, and ovarian carcinogenesis. However, whether N‐glycosylation of N‐cadherin plays a role in glioma remains unknown. Previous studies had indicated that N‐glycosylation could occur at three asparagine residues of N‐cadherin. By generating and over‐expressing N‐glycosylation‐deficient N‐cadherin mutants in the human glioma cell lines SHG66 and U87, we found that mutation of N402 but not of the other potentially N‐glycosylated residues destabilized N‐cadherin and led to its ubiquitylation and subsequent proteasomal degradation. Furthermore, destabilized N‐cadherin inhibited cadherin‐mediated cell–cell adhesion and promoted cell migration. Our findings reveal that N‐glycosylation controls N‐cadherin stability and plays a role in glioma migration. J. Cell. Biochem. 118: 1423–1431, 2017. © 2016 Wiley Periodicals, Inc.
Ethical use of animal models in musculoskeletal research
Authors: Allen Matthew J. , Hankenson Kurt D. , Goodrich Laurie , Boivin Gregory P. , von Rechenberg Brigitte 
Published: November 2016

ABSTRACTThe use of animals in research is under increasing scrutiny from the general public, funding agencies, and regulatory authorities. Our ability to continue to perform in‐vivo studies in laboratory animals will be critically determined by how researchers respond to this new reality. This Perspectives article summarizes recent and ongoing initiatives within ORS and allied organizations to ensure that musculoskeletal research is performed to the highest ethical standards. It goes on to present an overview of the practical application of the 3Rs (reduction, refinement, and replacement) into experimental design and execution, and discusses recent guidance with regard to improvements in the way in which animal data are reported in publications. The overarching goal of this review is to challenge the status quo, to highlight the absolute interdependence between animal welfare and rigorous science, and to provide practical recommendations and resources to allow clinicians and scientists to optimize the ways in which they undertake preclinical studies involving animals. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:740–751, 2017.