bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonality of soil moisture mediates responses of ecosystem phenology to elevated CO2 and warming in a semi‐arid grassland
Authors: Zelikova Tamara J. , Williams David G. , Hoenigman Rhonda , Blumenthal Dana M. , Morgan Jack A. , Pendall Elise 
Published: June 2015

Summary

Vegetation greenness, detected using digital photography, is useful for monitoring phenology of plant growth, carbon uptake and water loss at the ecosystem level. Assessing ecosystem phenology by greenness is especially useful in spatially extensive, water‐limited ecosystems such as the grasslands of the western United States, where productivity is moisture dependent and may become increasingly vulnerable to future climate change.

We used repeat photography and a novel means of quantifying greenness in digital photographs to assess how the individual and combined effects of warming and elevated CO2 impact ecosystem phenology (greenness and plant cover) in a semi‐arid grassland over an 8‐year period.

Climate variability within and among years was the proximate driver of ecosystem phenology. Individual and combined effects of warming and elevated CO2 were significant at times, but mediated by variation in both intra‐ and interannual precipitation. Specifically, warming generally enhanced plant cover and greenness early in the growing season but often had a negative effect during the middle of the summer, offsetting the early season positive effects. The individual effects of elevated CO2 on plant cover and greenness were generally neutral.

Opposing seasonal variations in the effects of warming and less so elevated CO2 cancelled each other out over an entire growing season, leading to no net effect of treatments on annual accumulation of greenness. The main effect of elevated CO2 dampened quickly, but warming continued to affect plant cover and plot greenness throughout the experiment. The combination of warming and elevated CO2 had a generally positive effect on greenness, especially early in the growing season and in later years of the experiment, enhanced annual greenness accumulation. However, interannual precipitation variation had larger effect on greenness, with two to three times greater greenness in wet years than in dry years.

Synthesis. Seasonal variation in timing and amount of precipitation governs grassland phenology, greenness and the potential for carbon uptake. Our results indicate that concurrent changes in precipitation regimes mediate vegetation responses to warming and elevated atmospheric CO2 in semi‐arid grasslands. Even small changes in vegetation phenology and greenness in response to warming and rising atmospheric CO2 concentrations, such as those we report here, can have large consequences for the future of grasslands.
Environmental changes drive the temporal stability of semi‐arid natural grasslands through altering species asynchrony
Authors: Xu Zhuwen , Ren Haiyan , Li Mai‐He , van Ruijven Jasper , Han Xingguo , Wan Shiqiang , Li Hui , Yu Qiang , Jiang Yong , Jiang Lin 
Published: June 2015

Summary

Stability is an important property of ecological systems, many of which are experiencing increasing levels of anthropogenic environmental changes. However, how these environmental changes influence ecosystem stability remains poorly understood.

We conducted an 8‐year field experiment in a semi‐arid natural grassland to explore the effects of two common environmental changes, precipitation and nitrogen enrichment, on the temporal stability of plant above‐ground biomass. A split‐plot design, with precipitation as the main plot factor and nitrogen as the subplot factor, was used. Temporal stability was related to potential explanatory abiotic and biotic variables using regressions and structural equation modelling.

Increase in growing season precipitation enhanced plant species richness and promoted temporal stability of plant above‐ground biomass. Nitrogen fertilization, however, reduced both plant species richness and temporal stability of plant above‐ground biomass. Contrary to expectations, species richness was not an important driver of stability. Instead, community temporal stability was mainly driven by water and nitrogen availability that modulated the degree of species asynchrony and, to a lesser extent, by the stability of dominant plant species.

Synthesis. Our results highlight the importance of limiting resources for regulating community biomass stability and suggest that the projected increase in growing season precipitation may potentially offset negative effects of increased atmospheric nitrogen deposition on species diversity and community stability in semi‐arid grasslands.
Occupational therapists' experiences of career progression following promotion
Authors: Nelson Helen , Giles Susan , McInnes Heather , Hitch Danielle 
Published: June 2015

Background/AimThe recruitment and retention of a skilled occupational therapy workforce is highlighted as a key issue for the profession, and yet there have been relatively few studies into the career progression of occupational therapists.MethodsA qualitative, naturalistic approach was adopted to answer the research question, using semi‐structured interviews to gather data. Eleven purposefully selected participants at an Australian health service were interviewed as part of this study. Categories representing the most common themes and topics supplied by participants within their individual interviews were identified and consolidated by the research team. The trustworthiness of this study was supported by strategies to maximise its credibility, dependability and confirmability.ResultsFour main themes were elicited from the data – (i) Readiness for progression, (ii) Tools and processes, (iii) Expectations and (iv) What I wish I had known first. Within these themes, related findings were also identified by both Grade 2 and Grade 3 staff.ConclusionsThis study indicates that the readiness of occupational therapists to climb the career ladder is influenced by the tools and processes they can utilise, and the expectations they have around the realities of their new position. With hindsight, participants highlighted some things they wish they had known at the time of transition, which appeared to have been implicit.Significance of StudyThis study is the first to address the common issues for occupational therapy staff around progression between grade levels. It therefore provides a basis for further research in other practice settings and for the development of supports for therapists climbing the career ladder.
Multiple Temporalities of Policy Circulation: Gradual, Repetitive and Delayed Processes of BRT Adoption in South African Cities
Authors: Wood Astrid 
Published: June 2015

AbstractIn 2006, bus rapid transit (BRT) swept across South African cities. Within three years of learning of the Bogotá model of BRT, Johannesburg's Rea Vaya opened, followed shortly by Cape Town's MyCiTi, while several other cities are at various stages of planning and implementation. This article traces the circulation of BRT across the South African urban context to expose the multiple and varied temporalities through which BRT came to appear as the only available solution. These earlier encounters, which include the first published discussion of BRT in South Africa in a 1973 conference report, study visits to Curitiba in the 1990s and a failed attempt to implement a Bogotá‐style BRT system in Cape Town in 2003, were instrumental in creating a fertile ground for later adoption practices. While it may appear as if circulated policies shorten the gestation time from policy introduction to policy adoption, these repeated attempts to implement circulated innovations ensure that the turnover only seems accelerated. This article unravels the story of BRT adoption, departing from the theoretical discussions of the policy circulation process as a rapid phenomenon, instead demonstrating that it is gradual, repetitive and at times delayed.
We Blame the Building! The Architecture of Distributed Responsibility
Authors: Beauregard Robert 
Published: June 2015

AbstractThis article makes use of actor‐network theory to reflect on how responsibility is distributed when efforts are made to change the built environment. More specifically, it is concerned with the way in which humans delegate responsibility to non‐human things and how these non‐human things then function as actors within heterogeneous settings. The overall intent is to erase the divide between culture and nature, human subjectivity and vibrant matter, and thereby change our relationship to ‘the city'. The argument is embedded in and illustrated by an architectural controversy that unfolded in New York City in late 2013 and early 2014 around the demolition by the Museum of Modern Art of an award‐winning and relatively new building––the American Folk Art Museum.
Development and Evaluation of a Multi‐Institutional Case Studies‐Based Course in Food Safety
Authors: Pleitner Aaron M. , Chapin Travis K. , Hammons Susan R. , Stelten Anna Van , Nightingale Kendra K. , Wiedmann Martin , Johnston Lynette M. , Oliver Haley F. 
Published: June 2015

AbstractDeveloping novel, engaging courses in food safety is necessary to train professionals in this discipline. Courses that are interactive and case‐based encourage development of critical thinking skills necessary for identifying and preventing foodborne disease outbreaks. The purpose of this study was to assess the efficacy of a case study module‐based course for upper division undergraduate and graduate students interested in food safety. Four independent case study modules were developed and implemented by 4 universities working in tandem over a semester course. All case studies incorporated molecular and epidemiological methods employed by professionals in food safety in outbreak investigations. Each case study was based on a (i) suspect foodborne pathogen, (ii) identification tools including biochemical test variations and pulsed field gel electrophoresis, multiplex PCR and/or whole genome sequencing, and (iii) suspect location and company type from farm to production site to restaurant. Pre‐ and postinstruction evaluations revealed significant increases in understanding of the concepts introduced through each module as demonstrated by overall mean normalized gain of 0.32 ± 0.35 (15% ± 19%; n = 60). Institution, role of instructor, prescore, and learning environment all played a significant role in the effects of overall learning. This study provides a successful model for a case study‐based course in food safety. The guidelines and materials developed by our group are available for use by other institutions.
Food Fish Identification from DNA Extraction Through Sequence Analysis
Authors: Hallen‐Adams Heather E. 
Published: June 2015

AbstractThis experiment exposed 3rd and 4th y undergraduates and graduate students taking a course in advanced food analysis to DNA extraction, polymerase chain reaction (PCR), and DNA sequence analysis. Students provided their own fish sample, purchased from local grocery stores, and the class as a whole extracted DNA, which was then subjected to PCR, gel electrophoresis, and Sanger sequencing. Students retrieved their sequences and identified their fish using the NCBI BLAST nucleotide database. Slightly more than half of the samples yielded sequences identical or close to expected (based on the identification of the fish on the packaging); some other samples matched unanticipated fish or other organisms, due to an incomplete database, minor sequencing errors, or laboratory contamination (human and fungal sequences); 1 canned tuna sample identified as hake could represent food fraud.
Enhanced computational methods for quantifying the effect of geographic and environmental isolation on genetic differentiation
Authors: Botta Filippo , Eriksen Casper , Fontaine Michaël C. , Guillot Gilles 
Published: June 2015

Summary

In a recent paper, Bradburd et al. (Evolution, 67, 2013, 3258) proposed a model to quantify the relative effect of geographic and environmental distance on genetic differentiation. Here, we enhance this method in several ways.

We modify the covariance model so as to fit better with mainstream geostatistical models and avoid mathematically ill‐behaved covariance functions. We extend the model – initially implemented only for co‐dominant bi‐allelic markers such as single nucleotide polymorphisms – to encompass highly polymorphic markers such as microsatellites. We implement and test a model selection procedure that allows users to assess which model (e.g. with or without an environment effect) is most suited. We code all our MCMC algorithms in a mix of compiled languages which allows us to decrease computing time by at least one order of magnitude. We propose an approximate inference and model selection method allowing us to deal with genomic data sets (several hundred thousands loci).

We also illustrate the potential of the method by re‐analysing three data sets, namely harbour porpoises in Europe, coyotes in California and herrings in the Baltic Sea.

The computer program developed here is freely available as an R package called sunder. It takes as input georeferenced allele counts at the individual or population level for co‐dominant markers. Program homepage: http://www2.imm.dtu.dk/~gigu/Sunder/.
Reading deficits in very low birthweight children are associated with vocabulary and attention issues at the age of seven
Authors: Leijon Ingemar , Ingemansson Fredrik , Nelson Nina , Wadsby Marie , Samuelsson Stefan 
Published: June 2015

AbstractAimThis Swedish study compared reading skills between seven‐year‐old children with a very low birthweight (VLBW) and controls with a normal birthweight, exploring associations between reading variables and cognition, parent‐rated behaviour, perinatal factors and family factors.MethodsWe studied 51 VLBW children, with no major neurodevelopmental impairments and attending their first year at a regular school, and compared them with the 51 sex‐ and age‐matched controls. The test battery, carried out at 7.8 ± 0.4 years of age, included reading skills, the Wechsler Intelligence Scale for Children – III and the Child Behaviour Checklist.ResultsVery low birthweight children with a mean birthweight of 1105 g (±291 g) and a gestational age of 28.8 (±2.2) weeks scored significantly lower in all reading subtests and cognition and demonstrated more behavioural problems than normal birthweight controls. We also found significant associations between poor vocabulary, combined with attention problems, and phonological awareness, rapid naming and spelling control. Perinatal factors had no association with reading function, and socio‐economic factors had very few.ConclusionVery low birthweight children demonstrated deficits in all reading domains and had poorer cognition and more behavioural problems at the age of seven, with reading ability related to vocabulary and attention.
Contrasting distribution patterns of invasive and naturalized non‐native species along environmental gradients in a semi‐arid montane ecosystem
Authors: Andersen Kelly M. , Naylor Bridgett J. , Endress Bryan A. , Parks Catherine G. 
Published: June 2015

AbstractQuestionsMountain systems have high abiotic heterogeneity over local spatial scales, offering natural experiments for examining plant species invasions. We ask whether functional groupings explain non‐native species spread into native vegetation and up elevation gradients. We examine whether non‐native species distribution patterns are related to environmental variables after controlling for elevation and, thus, driven by niche processes.LocationThe Wallowa Mountains, northeast Oregon, USA.MethodsWe surveyed non‐native plant species along three mountain roads and into the native habitat matrix to assess the extent of invasion success along distance from roadside and elevation gradients. We used GLM to predict single species occurrence probabilities, LMM to examine differences in distribution patterns among functional types, and pCCA to examine multivariate responses of the non‐native community to ecological variables.ResultsProbability of occurrence of the eight focal invasive species was not significantly related to distance from the road, but declined with elevation. Non‐native species with annual life history strategies were more restricted to lower elevations than perennial species. Non‐native species considered invasive occurred at lower minimum elevations than naturalized species. Shifts in the species composition of the non‐native plant community were related to changes in soil and climate variables.ConclusionsOur results suggest that invasive species have similar patterns of habitat associations and spread from roadsides to interior vegetation zones, whereas naturalized species partition environmental gradients in this semi‐arid montane ecosystem. Furthermore, annual and invasive species groups occupy lower elevations and perennial and naturalized species groups have invaded further up the mountain roads and into the native vegetation. Thus, functional groupings may explain contrasting distribution patterns of non‐native species and could be used to inform management strategies for non‐native species.
Cost‐Effectiveness Analysis of Latent versus Active Labor Hospital Admission for Medically Low‐Risk, Term Women
Authors: Tilden Ellen L. , Lee Vanessa R. , Allen Allison J. , Griffin Emily E. , Caughey Aaron B. 
Published: June 2015

AbstractObjectiveTo assess the outcomes and costs of hospital admission during the latent versus active phase of labor. Latent labor hospital admission has been consistently associated with elevated maternal risk for increased interventions, including epidural anesthesia and cesarean delivery, longer hospital stay, and higher utilization of hospital resources.MethodsA cost‐effectiveness model was built to simulate a theoretic cohort of 3.2 million term, medically low‐risk women either being admitted in latent labor (< 4 cm dilation) or delaying admission until active labor (≥ 4 cm dilation). Outcomes included epidural use, mode of delivery, stillbirth, maternal death, and costs of care. All probability, cost, and utility estimates were derived from the literature, and total quality‐adjusted life years were calculated. Sensitivity analyses and a Monte Carlo simulation were used to investigate the robustness of model assumptions.ResultsDelaying admission until active labor would result in 672,000 fewer epidurals, 67,232 fewer cesarean deliveries, and 9.6 fewer maternal deaths in our theoretic cohort as compared to admission during latent labor. Additionally, delaying admission results in a cost savings of $694 million annually in the United States. Sensitivity analyses indicated the model was robust within a wide range of probabilities and costs. Monte Carlo simulation found that delayed admission was the optimal strategy in 76.79 percent of trials.ConclusionDelaying admission until active labor is a dominant strategy, resulting in both better outcomes and lower costs. Issues related to clinical translation of these findings are explored.
A Biophysically‐Based Model of the Optical Properties of Skin Aging
Authors: Iglesias‐Guitian Jose A. , Aliaga Carlos , Jarabo Adrian , Gutierrez Diego 
Published: June 2015

AbstractThis paper presents a time‐varying, multi‐layered biophysically‐based model of the optical properties of human skin, suitable for simulating appearance changes due to aging. We have identified the key aspects that cause such changes, both in terms of the structure of skin and its chromophore concentrations, and rely on the extensive medical and optical tissue literature for accurate data. Our model can be expressed in terms of biophysical parameters, optical parameters commonly used in graphics and rendering (such as spectral absorption and scattering coefficients), or more intuitively with higher‐level parameters such as age, gender, skin care or skin type. It can be used with any rendering algorithm that uses diffusion profiles, and it allows to automatically simulate different types of skin at different stages of aging, avoiding the need for artistic input or costly capture processes. While the presented skin model is inspired on tissue optics studies, we also provided a simplified version valid for non‐diagnostic applications.
Panoramic Video from Unstructured Camera Arrays
Authors: Perazzi F. , Sorkine‐Hornung A. , Zimmer H. , Kaufmann P. , Wang O. , Watson S. , Gross M. 
Published: June 2015

AbstractWe describe an algorithm for generating panoramic video from unstructured camera arrays. Artifact‐free panorama stitching is impeded by parallax between input views. Common strategies such as multi‐level blending or minimum energy seams produce seamless results on quasi‐static input. However, on video input these approaches introduce noticeable visual artifacts due to lack of global temporal and spatial coherence. In this paper we extend the basic concept of local warping for parallax removal. Firstly, we introduce an error measure with increased sensitivity to stitching artifacts in regions with pronounced structure. Using this measure, our method efficiently finds an optimal ordering of pair‐wise warps for robust stitching with minimal parallax artifacts. Weighted extrapolation of warps in non‐overlap regions ensures temporal stability, while at the same time avoiding visual discontinuities around transitions between views. Remaining global deformation introduced by the warps is spread over the entire panorama domain using constrained relaxation, while staying as close as possible to the original input views. In combination, these contributions form the first system for spatiotemporally stable panoramic video stitching from unstructured camera array input.
High‐Order Recursive Filtering of Non‐Uniformly Sampled Signals for Image and Video Processing
Authors: Gastal Eduardo S. L. , Oliveira Manuel M. 
Published: June 2015

AbstractWe present a discrete‐time mathematical formulation for applying recursive digital filters to non‐uniformly sampled signals. Our solution presents several desirable features: it preserves the stability of the original filters; is well‐conditioned for low‐pass, high‐pass, and band‐pass filters alike; its cost is linear in the number of samples and is not affected by the size of the filter support. Our method is general and works with any non‐uniformly sampled signal and any recursive digital filter defined by a difference equation. Since our formulation directly uses the filter coefficients, it works out‐of‐the‐box with existing methodologies for digital filter design. We demonstrate the effectiveness of our approach by filtering non‐uniformly sampled signals in various image and video processing tasks including edge‐preserving color filtering, noise reduction, stylization, and detail enhancement. Our formulation enables, for the first time, edge‐aware evaluation of any recursive infinite impulse response digital filter (not only low‐pass), producing high‐quality filtering results in real time.
Parallel, Realistic and Controllable Terrain Synthesis
Authors: Gain J. , Merry B. , Marais P. 
Published: June 2015

AbstractThe challenge in terrain synthesis for virtual environments is to provide a combination of precise user control over landscape form, with interactive response and visually realistic results.We present a system that builds on parallel pixel‐based texture synthesis to enable interactive creation of an output terrain from a database of heightfield exemplars. We also provide modelers with control over height and surrounding slope by means of constraint points and curves; a paint‐by‐numbers interface for specifying the local character of terrain; coherence controls that allow localization of changes to the synthesized terrain; and copy‐paste functionality to directly transplant terrain regions.Together these contributions provide a level of realism that, based on user experiments, is indistinguishable from real source terrains; user control sufficient for precise placement of a variety of landforms, such as cliffs, ravines and mesas; and synthesis times of 165ms for a 10242 terrain grid.