bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing the niche‐breadth–range‐size hypothesis: habitat specialization vs. performance in Australian alpine daisies
Authors: Hirst Megan J. , Griffin Philippa C. , Sexton Jason P. , Hoffmann Ary A. 
Published: August 2017

AbstractRelatively common species within a clade are expected to perform well across a wider range of conditions than their rarer relatives, yet experimental tests of this “niche‐breadth–range‐size” hypothesis remain surprisingly scarce. Rarity may arise due to trade‐offs between specialization and performance across a wide range of environments. Here we use common garden and reciprocal transplant experiments to test the niche‐breadth–range‐size hypothesis, focusing on four common and three rare endemic alpine daisies (Brachyscomespp.) from the Australian Alps. We used three experimental contexts: (1) alpine reciprocal seedling experiment, a test of seedling survival and growth in three alpine habitat types differing in environmental quality and species diversity; (2) warm environment common garden, a test of whether common daisy species have higher growth rates and phenotypic plasticity, assessed in a common garden in a warmer climate and run simultaneously with experiment 1; and (3) alpine reciprocal seed experiment, a test of seed germination capacity and viability in the same three alpine habitat types as in experiment 1. In the alpine reciprocal seedling experiment, survival of all species was highest in the open heathland habitat where overall plant diversity is high, suggesting a general, positive response to a relatively productive, low‐stress environment. We found only partial support for higher survival of rare species in their habitats of origin. In the warm environment common garden, three common daisies exhibited greater growth and biomass than two rare species, but the other rare species performed as well as the common species. In the alpine reciprocal seed experiment, common daisies exhibited higher germination across most habitats, but rare species maintained a higher proportion of viable seed in all conditions, suggesting different life history strategies. These results indicate that some but not all rare, alpine endemics exhibit stress tolerance at the cost of reduced growth rates in low‐stress environments compared to common species. Finally, these findings suggest the seed stage is important in the persistence of rare species, and they provide only weak support at the seedling stage for the niche‐breadth–range‐size hypothesis.
Can snowshoe hares control treeline expansions?
Authors: Olnes Justin , Kielland Knut , Juday Glenn P. , Mann Daniel H. , Genet Hélène , Ruess Roger W. 
Published: August 2017

AbstractTreelines in Alaska are advancing in elevation and latitude because of climate warming, which is expanding the habitat available for boreal wildlife species, including snowshoe hares (Lepus americanus). Snowshoe hares are already present in tall shrub communities beyond treeline and are the main browser of white spruce (Picea glauca), the dominant tree species at treeline in Alaska. We investigated the processes involved in a “snowshoe hare filter” to white spruce establishment near treeline in Denali National Park, Alaska, USA. We modeled the pattern of spruce establishment from 1970 to 2009 and found that fewer spruce established during periods of high hare abundance. Multiple factors interact to influence browsing of spruce, including the hare cycle, snow depth and the characteristics of surrounding vegetation. Hares are abundant at treeline and may exclude spruce from otherwise optimal establishment sites, particularly floodplain locations with closed shrub canopies. The expansion of white spruce treeline in response to warming climate will be strongly modified by the spatial and temporal dynamics of the snowshoe hare filter.
Allocation, not male resistance, increases male frequency during epidemics: a case study in facultatively sexual hosts
Authors: Hite Jessica L. , Penczykowski Rachel M. , Shocket Marta S. , Griebel Katherine A. , Strauss Alexander T. , Duffy Meghan A. , Cáceres Carla E. , Hall Spencer R. 
Published: August 2017

AbstractWhy do natural populations vary in the frequency of sexual reproduction? Virulent parasites may help explain why sex is favored during disease epidemics. To illustrate, we show a higher frequency of males and sexually produced offspring in natural populations of a facultative parthenogenetic host during fungal epidemics. In a multi‐year survey of 32 lakes, the frequency of males (an index of sex) was higher in populations of zooplankton hosts with larger epidemics. A lake mesocosm experiment established causality: experimental epidemics produced a higher frequency of males relative to disease‐free controls. One common explanation for such a pattern involves Red Queen (RQ) dynamics. However, this particular system lacks key genetic specificity mechanisms required for the RQ, so we evaluated two other hypotheses. First, individual females, when stressed by infection, could increase production of male offspring vs. female offspring (a tenant of the “Abandon Ship” theory). Data from a life table experiment supports this mechanism. Second, higher male frequency during epidemics could reflect a purely demographic process (illustrated with a demographic model): males could resist infection more than females (via size‐based differences in resistance and mortality). However, we found no support for this resistance mechanism. A size‐based model of resistance, parameterized with data, revealed why: higher male susceptibility negated the lower exposure (a size‐based advantage) of males. These results suggest that parasite‐mediated increases in allocation to sex by individual females, rather than male resistance, increased the frequency of sex during larger disease epidemics.
Application of a Metal‐Mediated Base Pair to the Detection of Medicinally Relevant Single Nucleotide Polymorphisms
Authors: Jash Biswarup , Müller Jens 
Published: August 2017

AbstractInvited for the cover of this issue is the group of Jens Müller at Westfälische Wilhelms‐Universität Münster, Germany. The cover image shows figuratively how molecular beacons can be used to detect medicinally relevant single nucleotide polymorphisms.
Anionic lipopeptides from Bacillus mojavensis I4 as effective antihypertensive agents: Production, characterization, and identification
Authors: Ghazala Imen , Bouassida Mouna , Krichen Fatma , Manuel Benito José , Ellouz‐Chaabouni Semia , Haddar Anissa 
Published: August 2017

AbstractA new isolated Bacillus mojavensis strain I4 was found as producer of biosurfactants by different screening methods, such as parafilm M test, hemolytic activity, oil displacement test, emulsification index, surface tension, and lipase production assay. Enhanced biosurfactants production was obtained using glucose and glutamic acid as carbon and nitrogen sources, respectively. The optimal production of the biosurfactants was obtained by using a C/N ratio of 17, pH of 7.0, and temperature of 37°C. The surface tension was reduced to 29 mN/m and the emulsification index E24 of 62% was achieved after 72 h of culture. The purified biosurfactants showed stability with regard to surface tension reduction and emulsification in a wide range of temperatures (4–120°C), pH (4–10), and salinity (2–12% of NaCl). The thin‐layer chromatography showed that the produced biosurfactants were lipopeptides. The biosurfactants were characterized as a group of anionic lipopeptides with zeta potential measurement. Chromatographic characterization using HPLC revealed that I4 lipopeptides contained numerous isoforms and surfactin was the major component. Moreover, the I4 lipopeptides showed interesting angiotensin‐converting enzyme‐inhibitory activity.
Multimodal, automated detection of nocturnal motor seizures at home: Is a reliable seizure detector feasible?
Authors: van Andel Judith , Ungureanu Constantin , Arends Johan , Tan Francis , Van Dijk Johannes , Petkov George , Kalitzin Stiliyan , Gutter Thea , de Weerd Al , Vledder Ben , Thijs Roland , van Thiel Ghislaine , Roes Kit , Leijten Frans 
Published: August 2017

SummaryObjectiveAutomated seizure detection and alarming could improve quality of life and potentially prevent sudden, unexpected death in patients with severe epilepsy. As currently available systems focus on tonic–clonic seizures, we want to detect a broader range of seizure types, including tonic, hypermotor, and clusters of seizures.MethodsIn this multicenter, prospective cohort study, the nonelectroencephalographic (non‐EEG) signals heart rate and accelerometry were measured during the night in patients undergoing a diagnostic video‐EEG examination. Based on clinical video‐EEG data, seizures were classified and categorized as clinically urgent or not. Seizures included for analysis were tonic, tonic–clonic, hypermotor, and clusters of short myoclonic/tonic seizures. Features reflecting physiological changes in heart rate and movement were extracted. Detection algorithms were developed based on stepwise fulfillment of conditions during increases in either feature. A training set was used for development of algorithms, and an independent test set was used for assessing performance.ResultsNinety‐five patients were included, but due to sensor failures, data from only 43 (of whom 23 patients had 86 seizures, representing 402 h of data) could be used for analysis. The algorithms yield acceptable sensitivities, especially for clinically urgent seizures (sensitivity = 71–87%), but produce high false alarm rates (2.3–5.7 per night, positive predictive value = 25–43%). There was a large variation in the number of false alarms per patient.SignificanceIt seems feasible to develop a detector with high sensitivity, but false alarm rates are too high for use in clinical practice. For further optimization, personalization of algorithms may be necessary.
Validation of official erosion modelling based on high‐resolution radar rain data by aerial photo erosion classification
Authors: Fischer Franziska Katharina , Kistler Michael , Brandhuber Robert , Maier Harald , Treisch Melanie , Auerswald Karl 
Published: August 2017

AbstractThe universal soil loss equation (USLE) is the most frequently applied erosion prediction model and it is also implemented as an official decision‐making instrument for agricultural regulations. The USLE itself has been already validated using different approaches. Additional errors, however, arise from input data and interpolation procedures that become necessary for field‐specific predictions on a national scale for administrative purposes. In this study, predicted event soil loss using the official prediction system in Bavaria (Germany) was validated by comparison with aerial photo erosion classifications of 8100 fields. Values for the USLE factors were mainly taken from the official Bavarian high‐resolution (5 × 5 m2) erosion cadastre. As series of erosion events were examined, the cover and management factor was replaced by the soil loss ratio. The event erosivity factor was calculated from high‐resolution (1 × 1 km2, 5 min), rain gauge‐adjusted radar rain data (RADOLAN). Aerial photo erosion interpretation worked sufficiently well and average erosion predictions and visual classifications correlated closely. This was also true for data broken down to individual factors and different crops. There was no reason to assume a general invalidity of the USLE and the official parametrization procedures. Event predictions mainly suffered from errors in the assumed crop stage period and tillage practices, which do not reflect interannual and farm‐specific variation. In addition, the resolution of radar data (1 km2) did not seem to be sufficient to predict short‐term erosion on individual fields given the strong spatial gradients within individual rains. The quality of the input data clearly determined prediction quality. Differences between USLE predictions and observations are most likely caused by parametrization weaknesses but not by a failure of the model itself. Copyright © 2017 John Wiley & Sons, Ltd.
Effects of in ovo exposure to 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor)
Authors: Carro Tiffany , Walker Mary K. , Dean Karen M. , Ottinger Mary Ann 
Published: August 2017

Abstract

Tree swallow (Tachycineta bicolor) eggs from 2 uncontaminated sites, the Patuxent Research Refuge (Laurel, MD, USA) and the Cobleskill Reservoir (Cobleskill, NY, USA) were dosed with polychlorinated biphenyl (PCB) 77 to evaluate effects on the developing cardiovascular system. To ensure embryonic viability, treatments were administered into the air cell at embryonic day 2.5 including: untreated (control), vehicle (filtered sterilized fatty acid mixture), 100 ng/g and 1000 ng/g egg. Eggs were dosed in the field with 0.2 μL/egg, returned to the nest, collected at embryonic day 13, hatched in the laboratory, and necropsied. The PCB 77-treated hatchlings were compared with uninjected, vehicle-injected, and environmentally exposed hatchlings collected from a PCB-contaminated Upper Hudson River (NY, USA) site. The PCB 77-treated embryos showed no effects on hatching success or hatchling mortality, heart index, or morphological measures of 4 distinct heart layers (heart width, length, septal thickness, total and ventricular cavity area) compared with controls. Hatchlings that had received PCB 77 exhibited increased incidence of a cardiomyopathy and absence of the ventricular heart wall compact layer (Chi square test; p &lt; 0.001); environmentally exposed embryos showed no apparent effects. The compact layer is essential in development and overall heart function for ventricular cardiomyocyte proliferation and normal heart contraction. The finding that in ovo exposure to PCB 77 resulted in distinct cardiomyopathy has implications for long-term individual fitness. Environ Toxicol Chem 2018;37:116–125. © 2017 SETAC
Selforganization of modular activity of grid cells
Authors: Urdapilleta Eugenio , Si Bailu , Treves Alessandro 
Published: August 2017

AbstractA unique topographical representation of space is found in the concerted activity of grid cells in the rodent medial entorhinal cortex. Many among the principal cells in this region exhibit a hexagonal firing pattern, in which each cell expresses its own set of place fields (spatial phases) at the vertices of a triangular grid, the spacing and orientation of which are typically shared with neighboring cells. Grid spacing, in particular, has been found to increase along the dorso‐ventral axis of the entorhinal cortex but in discrete steps, that is, with a modular structure. In this study, we show that such a modular activity may result from the self‐organization of interacting units, which individually would not show discrete but rather continuously varying grid spacing. Within our “adaptation” network model, the effect of a continuously varying time constant, which determines grid spacing in the isolated cell model, is modulated by recurrent collateral connections, which tend to produce a few subnetworks, akin to magnetic domains, each with its own grid spacing. In agreement with experimental evidence, the modular structure is tightly defined by grid spacing, but also involves grid orientation and distortion, due to interactions across modules. Thus, our study sheds light onto a possible mechanism, other than simply assuming separate networks a priori, underlying the formation of modular grid representations.
Active offer of health services in French in Ontario: Analysis of reorganization and management strategies of health care organizations
Authors: Farmanova Elina , Bonneville Luc , Bouchard Louise 
Published: August 2017

SummaryBackgroundThe availability of health services in French is not only weak but also inexistent in some regions in Canada. As a result, estimated 78% of more than a million of Francophones living in a minority situation in Canada experience difficulties accessing health care in French. To promote the delivery of health services in French, publicly funded organizations are encouraged to take measures to ensure that French‐language services are clearly visible, available, easily accessible, and equivalent to the quality of services offered in English.ObjectiveThis study examines the reorganization and management strategies taken by health care organizations in Ontario that provide health services in French.MethodsReview and analysis of designation plans of a sample of health care organizations.ResultsFew health care organizations providing services in French have concrete strategies to guarantee availability, visibility, and accessibility of French‐language services.ConclusionsImplementation of the active offer of French‐language services is likely to be difficult and slow. The Ontario government must strengthen collaboration with health care organizations, Francophone communities, and other key actors participating in the designation process to help health care organizations build capacities for the effective offer of French‐language services.
Serum Levels of a Cathepsin-K Generated Periostin Fragment Predict Incident Low-Trauma Fractures in Postmenopausal Women Independently of BMD and FRAX
Authors: Bonnet Nicolas , Biver Emmanuel , Chevalley Thierry , Rizzoli René , Garnero Patrick , Ferrari Serge L 
Published: August 2017

ABSTRACT

Periostin is a matricellular protein involved in bone formation and bone matrix organization, but it is also produced by other tissues. Its circulating levels have been weakly associated with bone microstructure and prevalent fractures, possibly because periostin measured by the current commercial assays does not specifically reflect bone metabolism. In this context, we developed a new ELISA for a periostin fragment resulting from cathepsin K digestion (K-Postn). We hypothesized that circulating K-Postn levels could be associated with bone fragility. A total of 695 women (age 65.0 ± 1.5 years), enrolled in the Geneva Retirees Cohort (GERICO), were prospectively evaluated over 4.7 ± 1.9 years for the occurrence of low-trauma fractures. At baseline, we measured serum periostin, K-Postn, and bone turnover markers (BTMs), distal radius and tibia microstructure by HR-pQCT, hip and lumbar spine aBMD by DXA, and estimated fracture probability using the Fracture Risk Assessment Tool (FRAX). Sixty-six women sustained a low-trauma clinical fracture during the follow-up. Total periostin was not associated with fractures (HR [95% CI] per SD: 1.19 [0.89 to 1.59], p = 0.24). In contrast, K-Postn was significantly higher in the fracture versus nonfracture group (57.5 ± 36.6 ng/mL versus 42.5 ± 23.4 ng/mL, p &lt; 0.001) and associated with fracture risk (HR [95%CI] per SD: 2.14 [1.54 to 2.97], p &lt; 0.001). After adjustment for aBMD, FRAX, bone microstructure, or BTMs, K-Postn remained significantly associated with fracture risk. The performance of the fracture prediction models was improved by adding K-Postn to aBMD or FRAX (Harrell C index for fracture: 0.70 for aBMD + K-Post versus 0.58 for aBMD alone, p = 0.001; 0.73 for FRAX + K-Postn versus 0.65 for FRAX alone, p = 0.005). Circulating K-Postn predicts incident fractures independently of BMD, BTMs, and FRAX in postmenopausal women. Hence measurement of a periostin fragment resulting from in vivo cathepsin K digestion may help to identify subjects at high risk of fracture. © 2017 American Society for Bone and Mineral Research
The impact of preventive coping on business travelers' work and private life
Authors: Niessen Cornelia , Müller Teresa , Hommelhoff Sabine , Westman Mina 
Published: August 2017

SummaryFrequent business travel can be a burden for travelers' work and private life. We tested whether preventive coping (the proactive accumulation of resources in advance of potential stressors) makes such trips beneficial despite their potential to be stressful. In a longitudinal three‐wave study, we investigated whether frequent travel relates to an increase or decrease in work–life balance, emotional exhaustion, work engagement, and relationship satisfaction depending on preventive coping. Findings from a sample of 133 frequent business travelers revealed significant indirect effects for emotional exhaustion, work engagement, and relationship satisfaction through work–life balance. Among employees who engaged less in preventive coping, a higher number of business trips was related to a decrease in work–life balance, which, in turn, was related to more emotional exhaustion, less work engagement, and lower relationship satisfaction. Among those who reported higher preventive coping, we found opposing indirect effects: Frequent travel was related to an increase in work–life balance and, in turn, to less emotional exhaustion, more work engagement, and higher relationship satisfaction. These findings advance our knowledge in the field of business travel, future‐oriented coping, and work–life balance. They highlight that travelers and their organizations should resort to preventive coping to make frequent travel more beneficial.
Chemokine receptor‐7 (CCR7) deficiency leads to delayed development of joint damage and functional deficits in a murine model of osteoarthritis
Authors: Sambamurthy Nisha , Nguyen Vu , Smalley Ryan , Xiao Rui , Hankenson Kurt , Gan Justin , Miller Rachel E. , Malfait Anne‐Marie , Dodge George R. , Scanzello Carla R. 
Published: August 2017

ABSTRACTElevated chemokine receptor Ccr7 is observed in knee osteoarthritis (OA) and associated with severity of symptoms. In this study, we confirmed that CCR7 protein expression is elevated in synovial tissue from OA patients by immunohistochemical staining. We then investigated whether Ccr7 deficiency impacted structural and functional joint degeneration utilizing a murine model of OA. OA‐like disease was induced in male C57BL/6 and Ccr7‐deficient (Ccr7−/−) mice by destabilization of the medial meniscus (DMM). Functional deficits were measured by computer integrated monitoring of spontaneous activity every 4 weeks after DMM surgery up 16 weeks. Joint degeneration was evaluated at 6 and 19 weeks post‐surgery by histopathology, and subchondral bone changes analyzed by microCT. Results showed reduction in locomotor activities in DMM‐operated C57BL/6 mice by 8 weeks, while activity decreases in Ccr7−/− mice were delayed until 16 weeks. Histopathologic evaluation showed minimal protection from early cartilage degeneration (p = 0.06) and osteophytosis (p = 0.04) in Ccr7−/− mice 6 weeks post‐DMM compared to C57BL/6 controls, but not at 19 weeks. However, subchondral bone mineral density (p = 0.03) and histologic sclerosis (p = 0.02) increased in response to surgery in C57BL/6 mice at 6 weeks, while Ccr7−/− mice were protected from these changes. Our results are the first to demonstrate a role for Ccr7 in early development of functional deficits and subchondral bone changes in the DMM model. Understanding the mechanism of Ccr7 receptor signaling in the initiation of joint pathology and disability will inform the development of innovative therapies to slow symptomatic OA development after injury. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 36:864–875, 2018.