bluuebunny/crossref_metadata_2025_split huggingface dataset:
Community reorganization in forest understories buried by volcanic tephra
Authors: Zobel Donald B. , Antos Joseph A. 
Published: December 2017

AbstractDisturbance is a key factor contributing to community organization. Deposition of tephra (aerially transported volcanic ejecta) is a widespread disturbance of global relevance, but its effects on ecosystems have received limited attention. We studied forest understory community change for 30 yr following tephra deposition from the 1980 eruptions of Mount St. Helens (Washington State). Four old‐growth, subalpine conifer stands had a wide range of initial damage and patterns of community re‐development. We measured understory diversity, structure, and species composition and calculated relationships of plant cover with environment and cover of other plants. Overall, those communities that were altered greatly by tephra tended to converge with time on their pre‐eruption characteristics; however, substantial divergence occurred in some situations. For example, moss cover failed to reach pre‐eruption levels in all stands, whereas importance and diversity of woody plants sometimes greatly exceeded pre‐eruption values. Plant–environment relationships that were significant before the eruption disappeared and did not re‐develop. Smaller plants were more affected by environment than larger ones. Relationships before the eruption and also 30 yr after the eruption were primarily with other plant species, whereas relationships just after the eruption were with tephra depth and factors that modified its impact. Understory plant importance was usually lower beneath a tree canopy than in gaps, but there was little sign of interference from understory growth forms. Post‐eruption soil disturbance usually increased understory plant importance, while woody debris sometimes decreased herb and tree seedling cover. Tephra deposition, which did not immediately kill canopy trees, differed from the disturbances usually studied (e.g., fire, windthrow, bark beetles). Even so, these lessons from our study should be widely applicable: Similar species may respond differently; minor, early environmental differences may induce major, long‐term community change; successional trajectories may diverge from the pre‐disturbance community; and secondary disturbances may modify successional trajectories.
Implications of the forage maturation hypothesis for activity of partially migratory male and female deer
Authors: Debeffe Lucie , Maren Rivrud Inger , Brekkum Øystein , Meisingset Erling L. , Mysterud Atle 
Published: December 2017

AbstractPartial migration is common in a large variety of taxa in seasonally variable environments. Understanding the mechanisms underlying migration is important, as migration affects individual fitness. Migratory herbivores benefit from delayed forage maturation and hence higher food quality during migration and at their summer range, termed the forage maturation hypothesis (FMH). The link between diet quality and rumination time allows migrants eating a higher quality diet to spend less time on rumination, and they can thus allocate more time to additional feeding. However, such an argument implicitly assumes that deer are energy maximizers, while studies have reported also time minimization strategies under risk of predation. Male and female distributions are limited by different factors linked to both body size differences and reproductive strategies, but there is no study investigating differences in activity pattern according to the individual migratory patterns for male and female deer. We here unify the FMH with the hypotheses predicting sex‐specific time allocation strategies. To test predictions of sex‐specific activity of resident and migratory red deer (Cervus elaphus), we analyzed activity data of 286 individuals that were fitted with GPS collars from a population in western Norway. While migrants were more active during the migration itself, we found no differences in activity pattern between migrant and resident deer during the main growth season, neither in terms of proportion of daily time active nor in terms of daily mean movement speed, thus rejecting that deer were energy maximizers. Overall, we found that females were more active during the main growth season even after controlling for body size differences. These patterns are consistent with patterns predicted from sexual segregation theory linked to the reproductive strategy hypothesis. Our study highlights how the understanding of migration can be advanced by considering it in the context of different reproductive strategies of males and females.
Litter P content drives consumer production in detritus‐based streams spanning an experimental N:P gradient
Authors: Demi Lee M. , Benstead Jonathan P. , Rosemond Amy D. , Maerz John C. 
Published: December 2017

AbstractEcological stoichiometry theory (EST) is a key framework for predicting how variation in N:P supply ratios influences biological processes, at molecular to ecosystem scales, by altering the availability of C, N, and P relative to organismal requirements. We tested EST predictions by fertilizing five forest streams at different dissolved molar N:P ratios (2, 8, 16, 32, 128) for two years and tracking responses of macroinvertebrate consumers to the resulting steep experimental gradient in basal resource stoichiometry (leaf litter %N, %P, and N:P). Nitrogen and P content of leaf litter, the dominant basal resource, increased in all five streams following enrichment, with steepest responses in litter %P and N:P ratio. Additionally, increases in primary consumer biomass and production occurred in all five streams following N and P enrichment (averages across all streams: biomass by 1.2×, production by 1.6×). Patterns of both biomass and production were best predicted by leaf litter N:P and %P and were unrelated to leaf litter %N. Primary consumer production increased most in streams where decreases in leaf litter N:P were largest. Macroinvertebrate predator biomass and production were also strongly positively related to litter %P, providing robust experimental evidence for the primacy of P limitation at multiple trophic levels in these ecosystems. However, production of predatory macroinvertebrates was not related directly to primary consumer production, suggesting the importance of additional controls for macroinvertebrates at upper trophic positions. Our results reveal potential drivers of animal production in detritus‐based ecosystems, including the relative importance of resource quality vs. quantity. Our study also sheds light on the more general impacts of variation in N:P supply ratio on nutrient‐poor ecosystems, providing strong empirical support for predictions that nutrient enrichment increases food web productivity whenever large elemental imbalances between basal resources and consumer demand are reduced.
Emma Lucy Braun's forest plots in eastern North America
Authors: Ricklefs Robert E. 
Published: December 2017

AbstractRelative abundances of tree species are presented for the 348 forest plots described in E. Lucy Braun's (1950) book, Deciduous Forests of Eastern North America (Hafner, New York, facsimile reprint 1972). Information about the plots includes forest type, location with latitude and longitude, WorldClim climate variables, and sources of original studies where applicable. No copyright restrictions are associated with the use of this data set. Please cite this article when the data are used in other publications.
Model Biological Membranes and Possibilities of Application of Electrochemical Impedance Spectroscopy for their Characterization
Authors: Skalová Štěpánka , Vyskočil Vlastimil , Barek Jiří , Navrátil Tomáš 
Published: December 2017

AbstractBiological membranes are essential parts of living systems. They represent an interface between intracellular and extracellular space. Depending on their structure, they often perform very complex functions and play an important role in the transport of both charged and uncharged particles in any organism. Structure of the biological membranes, which play very important role in electrochemical processes inside living organisms, is very complicated and still not precisely defined and explained. Model lipid membranes are used to gain detail information about properties of real biological membranes and about associated electrochemical processes. Electrochemistry, especially electrochemical impedance spectroscopy (EIS), can play a useful role in the characterization of properties of model lipid membranes (planar and supported lipid bilayers, tethered lipid membranes, liposomes, etc.). This review is focused on model biological membranes and the possibilities and limitations of electrochemical methods and namely of EIS in this field.
Deriving formulas for an unsteady virtual velocity of bedload tracers
Authors: Klösch Mario , Habersack Helmut 
Published: December 2017

AbstractIn a flume experiment with steady flow conditions, H. A. Einstein recognised the transport of bedload particles as consisting of steps of rolling, sliding, or saltation with intermittent rest periods, and introduced the concept of an average, ‘virtual’ transport velocity. This virtual velocity then has also been derived from tracer studies in the field by dividing the travelled distance of a tracer by the duration of competent flow. As a consequence, the virtual velocity in the field is represented by one single value only, despite the unsteady flow variables. Tracer measurements in a river have not been yet used to express transport velocity as a direct function of these actual variables, and insights from tracer measurements into the processes of sediment transport remain limited. In particular, the unsteady conditions for bedload in the field have impeded the derivation of sediment transport characteristics as determined from laboratory experiments, as well as the transfer of laboratory insights to a field setting. We introduce a method of data regression for the derivation of an ‘unsteady’ virtual velocity from repeated surveys of tracer positions. The regression program called graVel (provided as supplementary material) relates the integral of an excess flow variable term to measured travel distances, yielding the most probable threshold value for entrainment and the coefficient of linear and non‐linear formulas. An extended regression allows additional fitting of the exponent in non‐linear formulas. Application to published tracer data from the Mameyes River, Puerto Rico, shows that the unsteady virtual velocity is more likely governed by non‐linear relations to excess Shields stress, similar to bedload transport, than by relations linking the particle velocity linearly to excess shear velocity. Partial agreements with non‐dimensional results derived from the larger, non‐wadeable Mur River encourage the establishment of a generalised formula for the unsteady virtual velocity. Copyright © 2017 John Wiley & Sons, Ltd.
Effects of rainfall, overland flow and their interactions on peatland interrill erosion processes
Authors: Li Changjia , Holden Joseph , Grayson Richard 
Published: December 2017

AbstractInterrill erosion processes on gentle slopes are affected by mechanisms of raindrop impact, overland flow and their interaction. However, limited experimental work has been conducted to understand how important each of the mechanisms are and how they interact, in particular for peat soil. Laboratory simulation experiments were conducted on peat blocks under two slopes (2.5° and 7.5°) and three treatments: Rainfall, where rainfall with an intensity of 12 mm h−1 was simulated; Inflow, where upslope overland flow at a rate of 12 mm h−1 was applied; and Rainfall + Inflow which combined both Rainfall and Inflow. Overland flow, sediment loss and overland flow velocity data were collected and splash cups were used to measure the mass of sediment detached by raindrops. Raindrop impact was found to reduce overland flow by 10 to 13%, due to increased infiltration, and reduce erosion by 47% on average for both slope gradients. Raindrop impact also reduced flow velocity (80–92%) and increased roughness (72–78%). The interaction between rainfall and flow was found to significantly reduce sediment concentrations (73–85%). Slope gradient had only a minor effect on overland flow and sediment yield. Significantly higher flow velocities and sediment yields were observed under the Rainfall + Inflow treatment compared to the Rainfall treatment. On average, upslope inflow was found to increase erosion by 36%. These results indicate that overland flow and erosion processes on peat hillslopes are affected by upslope inflow. There was no significant relationship between interrill erosion and overland flow, whereas stream power had a strong relationship with erosion. These findings help improve our understanding of the importance of interrill erosion processes on peat. Copyright © 2017 John Wiley & Sons, Ltd.
Hallucination‐ and speech‐specific hypercoupling in frontotemporal auditory and language networks in schizophrenia using combined task‐based fMRI data: An fBIRN study
Authors: Lavigne Katie M. , Woodward Todd S. 
Published: December 2017

AbstractHypercoupling of activity in speech‐perception‐specific brain networks has been proposed to play a role in the generation of auditory‐verbal hallucinations (AVHs) in schizophrenia; however, it is unclear whether this hypercoupling extends to nonverbal auditory perception. We investigated this by comparing schizophrenia patients with and without AVHs, and healthy controls, on task‐based functional magnetic resonance imaging (fMRI) data combining verbal speech perception (SP), inner verbal thought generation (VTG), and nonverbal auditory oddball detection (AO). Data from two previously published fMRI studies were simultaneously analyzed using group constrained principal component analysis for fMRI (group fMRI‐CPCA), which allowed for comparison of task‐related functional brain networks across groups and tasks while holding the brain networks under study constant, leading to determination of the degree to which networks are common to verbal and nonverbal perception conditions, and which show coordinated hyperactivity in hallucinations. Three functional brain networks emerged: (a) auditory‐motor, (b) language processing, and (c) default‐mode (DMN) networks. Combining the AO and sentence tasks allowed the auditory‐motor and language networks to separately emerge, whereas they were aggregated when individual tasks were analyzed. AVH patients showed greater coordinated activity (deactivity for DMN regions) than non‐AVH patients during SP in all networks, but this did not extend to VTG or AO. This suggests that the hypercoupling in AVH patients in speech‐perception‐related brain networks is specific to perceived speech, and does not extend to perceived nonspeech or inner verbal thought generation.
Teachers become cocreators through participation in a teacher professional development (TPD) course in a resource constraint environment in South Africa
Authors: Botha Adele , Herselman Marlien 
Published: December 2017

AbstractThe purpose of this paper is to provide insight into how teachers became cocreators by merging their existing knowledge of their subject, context, and new knowledge of using mobile tablets towards enhancing their teaching practices. This was achieved in a specific area in the Eastern Cape Province of South Africa over a period of 3 years. The intentional situating of teachers as cocreators was implementation through a teacher professional development (TPD) course. The course consisted of 10 modules presented and completed over a 1‐year period. The TPD course was developed as an artefact using Design Science as a methodology with 3 iterations of implementation to refine it. The development of the course and its iterative implementation and refinement was grounded in the Living Lab open innovation approach with elements of gamification (coopetition), and various stakeholders were incorporated. Structuration theory was applied to indicate the “duality of structure” where structure and agency are related and dependent on each other and agents' actions produce, reproduce, and develop social structures. Technology endowments were integrated as part of the gamification and were dependent on predefined cocreation events. Each event was linked to a badge, and teachers had to provide practice‐based evidence of how new knowledge, proficiencies, and skills gained during the TPD sessions was adapted to their own subject and context knowledge and practically implemented in their classrooms. This presents an innovative way to introduce and use tablets in teaching and learning (structure) as teachers (agents) are acknowledged as domain and subject experts, and through exposure to technology and pedagogical strategies in using the technology (resources), they become cocreators of their own new enhanced classroom practice (social structures) and adopted the technology.
Examining capability enhancement through mobile phone use:The case of SouthernGhana
Authors: Yim Moonjung , Gomez Ricardo 
Published: December 2017

AbstractWith near half of African population being unique subscribers of mobile phones, we are beginning to understand how people in the continent—and more broadly in the Global South—are interacting with their mobile phone in everyday life, and whether it contributes to development and to capability enhancement, following Amartya Sen's notions. Analyzing interviews on mobile phone uses in Southern Ghana based on Sen's Capability Approach and Dorothea Kleine'sChoiceFramework, we claim that real‐life uses of mobile phones demonstrate capability enhancement, as it facilitates (1) communication with weak and strong social ties which generates positive outcomes such as exchange of emotional support, information or knowledge, and mobilization of financial resources; (2) information retrieval linked to knowledge expansion and occupational practices; and (3) flexibility in life at work and overcoming physical weakness. The study seeks to contribute towards more profound understanding of the role that mobile phone uses play in development context by looking at everyday uses. In turn, it seeks to address the question of “can mobile phone uses support development in a sustainable and inclusive way that would lead to a quality of life deemed as valuable and meaningful by people?”
An Ectopic Imaging Window for Intravital Imaging of Engineered Bone Tissue
Authors: Stiers Pieter‐Jan , van Gastel Nick , Moermans Karen , Stockmans Ingrid , Carmeliet Geert 
Published: December 2017

ABSTRACTTissue engineering is a promising branch of regenerative medicine, but its clinical application remains limited because thorough knowledge of the in vivo repair processes in these engineered implants is limited. Common techniques to study the different phases of bone repair in mice are destructive and thus not optimal to gain insight into the dynamics of this process. Instead, multiphoton‐intravital microscopy (MP‐IVM) allows visualization of (sub)cellular processes at high resolution and frequency over extended periods of time when combined with an imaging window that permits optical access to implants in vivo. In this study, we have developed and validated an ectopic imaging window that can be placed over a tissue‐engineered construct implanted in mice. This approach did not interfere with the biological processes of bone regeneration taking place in these implants, as evidenced by histological and micro–computed tomography (μCT)‐based comparison to control ectopic implants. The ectopic imaging window permitted tracking of individual cells over several days in vivo. Furthermore, the use of fluorescent reporters allowed visualization of the onset of angiogenesis and osteogenesis in these constructs. Taken together, this novel imaging window will facilitate further analysis of the spatiotemporal regulation of cellular processes in bone tissue–engineered implants and provides a powerful tool to enhance the therapeutic potential of bone tissue engineering. © 2017 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Association of interferon gamma gene polymorphism and susceptibility to hepatitis C virus infection in Egyptian patients: A multicenter, family‐based study
Authors: El‐Bendary Mahmoud , Neamatallah Mustafa , Elalfy Hatem , Besheer Tarek , El‐Setouhy Maged , Kasim Nihal , Abou El‐Khier Noha T , Kamel Emily , Eladl Abdel‐Hamid , El‐Waseef Ahmad , Abdel‐Aziz Abdel‐Aziz F , Esmat Gamal 
Published: December 2017

Background and AimPolymorphisms in some genes may influence the persistence of hepatitis C virus (HCV) infection, clinical outcome, HCV replication, and liver damage. This study was conducted to investigate the role of the interferon gamma (IFN‐γ) gene at (+874 T/A, −764 G/C, −179 C/A) single‐nucleotide polymorphisms (SNPs) and its receptor (IFN‐γR2) at (rs 2786067 A/C) SNP in the susceptibility of Egyptian families to HCV infection with high‐resolution techniques.MethodsIn total, 517 Egyptian families, with 2246 subjects, were recruited to this study from the Upper and Lower Egypt governorates and were classified into three groups: 1034 patients with chronic hepatitis C virus, 108 subjects with spontaneous virus clearance (SVC), and 1104 subjects as a healthy control group. All subjects were genotyped for (+874 T/A, rs2430561, −764 G/C, rs2069707, −179 C/A, rs2069709, and rs 27860067, A/C) SNPs of the IFN‐γ gene using the allelic discrimination real‐time polymerase chain reaction technique and were confirmed using sequence‐based typing.ResultsThe carriage of T allele of (+874) IFN‐γ is a risky allele and was significantly higher in chronic hepatitis C more than other two groups (odds ratio [OR]: 2.6646, P < 0.0002). On the other hand, the C allele of (−764, rs2069707) is a protective allele and was higher in SVC than the other two groups (OR: 0.2709, P < 0.0001). However, both (−179 C/A, rs 2069709) and (rs 27860067, A/C) SNPs are not polymorphic enough to be studied in the Egyptian population.ConclusionsHCV infection is associated with the T allele of (+874 rs2430561), while SVC of HCV is associated with the C allele of (−764, rs2069707) of the IFN‐γ gene.
CD300 family receptors regulate eosinophil survival, chemotaxis, and effector functions
Authors: Rozenberg Perri , Reichman Hadar , Moshkovits Itay , Munitz Ariel 
Published: December 2017

Abstract
The CD300 family of receptors is an evolutionary conserved receptor family that belongs to the Ig superfamily and is expressed predominantly by the myeloid lineage. Over the past couple of years, accumulating data have shown that eosinophils express various Ig superfamily receptors that regulate key checkpoints in their biology including their maturation, transition from the bone marrow to the peripheral blood, migration, adhesion, survival, and effector functions in response to numerous activating signals such as IL-4, IL-33, and bacteria. In this review, we will present the emerging roles of CD300 family receptors and specifically CD300a and CD300f in the regulation of these eosinophil activities. The structure and expression pattern of these molecules will be discussed and their involvement in suppressing or co-activating eosinophil functions in health and disease will be illustrated.
CD300 receptors can regulate key eosinophil functions in response to diverse stimuli. Therefore, CD300 family receptors may provide pharmacological targets for eosinophil-associated diseases.