bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matching seed to site by climate similarity: Techniques to prioritize plant materials development and use in restoration
Authors: Doherty Kyle D. , Butterfield Bradley J. , Wood Troy E. 
Published: January 2017

AbstractLand management agencies are increasing the use of native plant materials for vegetation treatments to restore ecosystem function and maintain natural ecological integrity. This shift toward the use of natives has highlighted a need to increase the diversity of materials available. A key problem is agreeing on how many, and which, new accessions should be developed. Here we describe new methods that address this problem. Our methods use climate data to calculate a climate similarity index between two points in a defined extent. This index can be used to predict relative performance of available accessions at a target site. In addition, the index can be used in combination with standard cluster analysis algorithms to quantify and maximize climate coverage (mean climate similarity), given a modeled range extent and a specified number of accessions. We demonstrate the utility of this latter feature by applying it to the extents of 11 western North American species with proven or potential use in restoration. First, a species‐specific seed transfer map can be readily generated for a species by predicting performance for accessions currently available; this map can be readily updated to accommodate new accessions. Next, the increase in climate coverage achieved by adding successive accessions can be explored, yielding information that managers can use to balance ecological and economic considerations in determining how many accessions to develop. This approach identifies sampling sites, referred to as climate centers, which contribute unique, complementary, climate coverage to accessions on hand, thus providing explicit sampling guidance for both germplasm preservation and research. We examine how these and other features of our approach add to existing methods used to guide plant materials development and use. Finally, we discuss how these new methods provide a framework that could be used to coordinate native plant materials development, evaluation, and use across agencies, regions, and research groups.
Community assembly in Lake Tanganyika cichlid fish: quantifying the contributions of both niche‐based and neutral processes
Authors: Janzen Thijs , Alzate Adriana , Muschick Moritz , Maan Martine E. , van der Plas Fons , Etienne Rampal S. 
Published: January 2017

AbstractThe cichlid family features some of the most spectacular examples of adaptive radiation. Evolutionary studies have highlighted the importance of both trophic adaptation and sexual selection in cichlid speciation. However, it is poorly understood what processes drive the composition and diversity of local cichlid species assemblages on relatively short, ecological timescales. Here, we investigate the relative importance of niche‐based and neutral processes in determining the composition and diversity of cichlid communities inhabiting various environmental conditions in the littoral zone of Lake Tanganyika, Zambia. We collected data on cichlid abundance, morphometrics, and local environments. We analyzed relationships between mean trait values, community composition, and environmental variation, and used a recently developed modeling technique (STEPCAM) to estimate the contributions of niche‐based and neutral processes to community assembly. Contrary to our expectations, our results show that stochastic processes, and not niche‐based processes, were responsible for the majority of cichlid community assembly. We also found that the relative importance of niche‐based and neutral processes was constant across environments. However, we found significant relationships between environmental variation, community trait means, and community composition. These relationships were caused by niche‐based processes, as they disappeared in simulated, purely neutrally assembled communities. Importantly, these results can potentially reconcile seemingly contrasting findings in the literature about the importance of either niche‐based or neutral‐based processes in community assembly, as we show that significant trait relationships can already be found in nearly (but not completely) neutrally assembled communities; that is, even a small deviation from neutrality can have major effects on community patterns.
Interactions between body size, abundance, seasonality, and phenology in forest beetles
Authors: Gillespie Mark A. K. , Birkemoe Tone , Sverdrup‐Thygeson Anne 
Published: January 2017

AbstractBody size correlates with a large number of species traits, and these relationships have frequently been used to explain patterns in populations, communities, and ecosystems. However, diverging patterns occur, and there is a need for more data on different taxa at different scales. Using a large dataset of 155,418 individual beetles from 588 species collected over 13 years of sampling in Norway, we have explored whether body size predicts abundance, seasonality, and phenology in insects. Seasonality is estimated here by flight activity period length and phenology by peak activity. We develop several methods to estimate these traits from low‐resolution sampling data. The relationship between abundance and body size was significant and as expected; the smaller species were more abundant. However, smaller species tended to fly for longer periods of the summer and peaked in midsummer, while larger species were restricted to shorter temporal windows. Further analysis of repeated sampling from a single location suggested that smaller species had increased flight period lengths in warmer years, but larger species showed the opposite pattern. The results 1) indicate that smaller species are likely to be disproportionately valuable in ecological interactions, and 2) provide potential insights into the traits influencing the vulnerability of some larger species to disturbances and climate change.
Portfolio effects, climate change, and the persistence of small populations: analyses on the rare plant Saussurea weberi
Authors: Abbott Ronald E. , Doak Daniel F. , DeMarche Megan L. 
Published: January 2017

AbstractThe mechanisms that stabilize small populations in the face of environmental variation are crucial to their long‐term persistence. Building from diversity–stability concepts in community ecology, within‐population diversity is gaining attention as an important component of population stability. Genetic and microhabitat variation within populations can generate diverse responses to common environmental fluctuations, dampening temporal variability across the population as a whole through portfolio effects. Yet, the potential for portfolio effects to operate at small scales within populations or to change with systematic environmental shifts, such as climate change, remain largely unexplored. We tracked the abundance of a rare alpine perennial plant, Saussurea weberi, in 49 1‐m2 plots within a single population over 20 yr. We estimated among‐plot correlations in log annual growth rate to test for population‐level synchrony and quantify portfolio effects across the 20‐yr study period and also in 5‐yr subsets based on June temperature quartiles. Asynchrony among plots, due to different plot‐level responses to June temperature, reduced overall fluctuations in abundance and the probability of decline in population models, even when accounting for the effects of density dependence on dynamics. However, plots became more synchronous and portfolio effects decreased during the warmest years of the study, suggesting that future climate warming may erode stabilizing mechanisms in populations of this rare plant.
Ecosystem flux and biotic modification as drivers of metaecosystem dynamics
Authors: Limberger Romana , Birtel Julia , Farias Daniel d. S. , Matthews Blake 
Published: January 2017

AbstractThe fluxes of energy, matter, and organisms are important structuring forces of metaecosystems. Such ecosystem fluxes likely interact with environmental heterogeneity and differentially affect the diversity of multiple communities. In an aquatic mesocosm experiment, we tested how ecosystem flux and patch heterogeneity affected the diversity of bacteria, phytoplankton, and zooplankton metacommunities, and the structure and functioning of metaecosystems. We built metaecosystems consisting of three mesocosms that were either connected by flux of living organisms, organic material, and nutrients (alive ecosystem flux) or only by flux of organic material and nutrients (dead ecosystem flux). The three patches of each metaecosystem were either homogeneous or heterogeneous in nutrient loading. We found that the three groups of organisms responded differently to our treatments: flux of living organisms increased bacterial diversity irrespective of nutrient heterogeneity, while flux effects on phytoplankton diversity depended on nutrient heterogeneity, potentially indicating source‐sink effects. Although zooplankton diversity was largely unaffected by our manipulations, subtle changes of community composition in response to ecosystem flux had strong effects on lower trophic levels, highlighting the importance of indirect flux effects via alterations in trophic interactions. Furthermore, differential effects of communities on the mean and spatial variability of local abiotic environments influenced the development of metaecosystem heterogeneity through time. Despite identical nutrient loading at the scale of the metaecosystem, abiotic conditions diverged between homogeneous and heterogeneous metaecosystems. For example, concentrations in dissolved organic carbon (DOC) were higher in homogeneous than heterogeneous metaecosystems, possibly because of differential responses of the algal community to local environmental conditions. Similarly, we found that flux effects on organisms translated into effects on DOC concentrations at the patch level, suggesting that flux‐mediated changes in abundances of species can alter abiotic conditions. Our study shows that the dynamics of biotic and abiotic compartments of spatially structured ecosystems are intricately linked, highlighting the importance of integrating metacommunity and metaecosystem perspectives.
Numerical investigation of the resistance of precast RC pinned beam‐to‐column connections under shear loading
Authors: Kremmyda Georgia D. , Fahjan Yasin M. , Psycharis Ioannis N. , Tsoukantas Spyros G. 
Published: January 2017

SummaryIn precast technology, the effective design and construction are related to the behaviour of the connections between the structural members in order to cater for all service, environmental and earthquake load conditions. Therefore, the design and detailing of the connections should be undertaken consistently and with awareness of the desired structural response. In the research presented herein, an analytical expression is proposed for the prediction of the resistance of precast pinned connections under shear monotonic and cyclic loading. The proposed formula addresses the case where the failure of the connection occurs with simultaneous flexural failure of the dowel and compression failure of the concrete around the dowel, expected to occur either when (i) adequate concrete cover of the dowels is provided (d > 6D) or (ii) adequate confining reinforcement (as defined in the article) is foreseen around the dowels in the case of small concrete covers (d < 6D). The expression is calibrated against available experimental data and numerical results derived from a nonlinear numerical investigation. Emphasis is given to identifying the effect of several parameters on the horizontal shear resistance of the connection such as: the number and diameter of the dowels; the strength of materials (concrete, grout, steel); the concrete cover of the dowels; the thickness of the elastomeric pad; the type of shear loading (monotonic or cyclic); the pre‐existing axial stress in the dowels; and the rotation of the joint. In addition, recommendations for the design of precast pinned beam‐to‐column connections are given, especially when the connections are utilised in earthquake resistant structures. Copyright © 2017 John Wiley & Sons, Ltd.
Comparison of four methods for bioavailability-based risk assessment of mixtures of Cu, Zn, and Ni in freshwater
Authors: Van Regenmortel Tina , Nys Charlotte , Janssen Colin R. , Lofts Stephen , De Schamphelaere Karel A.C. 
Published: January 2017

Abstract

Although chemical risk assessment is still mainly conducted on a substance-by-substance basis, organisms in the environment are typically exposed to mixtures of substances. Risk assessment procedures should therefore be adapted to fit these situations. Four mixture risk assessment methodologies were compared for risk estimations of mixtures of copper (Cu), zinc (Zn), and nickel (Ni). The results showed that use of the log-normal species sensitivity distribution (SSD) instead of the best-fit distribution and sampling species sensitivities independently for each metal instead of using interspecies correlations in metal sensitivity had little impact on risk estimates. Across 4 different monitoring datasets, between 0% and 52% of the target water samples were estimated to be at risk, but only between 0% and 15% of the target water samples were at risk because of the mixture of metals and not any single metal individually. When a natural baseline database was examined, it was estimated that 10% of the target water samples were at risk because of single metals or their mixtures; when the most conservative method was used (concentration addition [CA] applied directly to the SSD, i.e., CASSD). However, the issue of metal mixture risk at geochemical baseline concentrations became relatively small (2% of target water samples) when a theoretically more correct method was used (CA applied to individual dose response curves, i.e., CADRC). Finally, across the 4 monitoring datasets, the following order of conservatism for the 4 methods was shown (from most to least conservative, with ranges of median margin of safety [MoS] relative to CASSD): CASSD &gt; CADRC (MoS = 1.17–1.25) &gt; IADRC (independent action (IA) applied to individual dose-response curves; MoS = 1.38–1.60) &gt; IASSD (MoS = 1.48–1.72). Therefore, it is suggested that these 4 methods can be used in a general tiered scheme for the risk assessment of metal mixtures in a regulatory context. In this scheme, the CASSD method could serve as a first (conservative) tier to identify situations with likely no potential risk at all, regardless of the method used (the sum toxic unit expressed relative to the 5% hazardous concentration [SumTUHC5] &lt; 1) and the IASSD method to identify situations of potential risk, also regardless of the method used (the multisubstance potentially affected fraction of species using the IASSD method [msPAFIA,SSD] &gt; 0.05). The CADRC and IADRC methods could be used for site-specific assessment for situations that fall in between (SumTUHC5 &gt; 1 and msPAFIA,SSD &lt; 0.05). Environ Toxicol Chem 2017;36:2123–2138. © 2017 SETAC
Clinical impact of intraoperative CCEP monitoring in evaluating the dorsal language white matter pathway
Authors: Yamao Yukihiro , Suzuki Kengo , Kunieda Takeharu , Matsumoto Riki , Arakawa Yoshiki , Nakae Takuro , Nishida Sei , Inano Rika , Shibata Sumiya , Shimotake Akihiro , Kikuchi Takayuki , Sawamoto Nobukatsu , Mikuni Nobuhiro , Ikeda Akio , Fukuyama Hidenao , Miyamoto Susumu 
Published: January 2017

AbstractIn order to preserve postoperative language function, we recently proposed a new intraoperative method to monitor the integrity of the dorsal language pathway (arcuate fasciculus; AF) using cortico–cortical evoked potentials (CCEPs). Based on further investigations (20 patients, 21 CCEP investigations), including patients who were not suitable for awake surgery (five CCEP investigations) or those without preoperative neuroimaging data (eight CCEP investigations including four with untraceable tractography due to brain edema), we attempted to clarify the clinical impact of this new intraoperative method. We monitored the integrity of AF by stimulating the anterior perisylvian language area (AL) by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. After tumor resection, single‐pulse electrical stimuli were also applied to the floor of the removal cavity to record subcortico‐cortical evoked potentials (SCEPs) at AL and PL in 12 patients (12 SCEP investigations). We demonstrated that (1) intraoperative dorsal language network monitoring was feasible even when patients were not suitable for awake surgery or without preoperative neuroimaging studies, (2) CCEP is a dynamic marker of functional connectivity or integrity of AF, and CCEP N1 amplitude could even become larger after reduction of brain edema, (3) a 50% CCEP N1 amplitude decline might be a cut‐off value to prevent permanent language dysfunction due to impairment of AF, (4) a correspondence (<2.0 ms difference) of N1 onset latencies between CCEP and the sum of SCEPs indicates close proximity of the subcortical stimulus site to AF (<3.0 mm). Hum Brain Mapp 38:1977–1991, 2017. © 2017 Wiley Periodicals, Inc.
From hippocampus to whole‐brain: The role of integrative processing in episodic memory retrieval
Authors: Geib Benjamin R. , Stanley Matthew L. , Dennis Nancy A. , Woldorff Marty G. , Cabeza Roberto 
Published: January 2017

AbstractMultivariate functional connectivity analyses of neuroimaging data have revealed the importance of complex, distributed interactions between disparate yet interdependent brain regions. Recent work has shown that topological properties of functional brain networks are associated with individual and group differences in cognitive performance, including in episodic memory. After constructing functional whole‐brain networks derived from an event‐related fMRI study of memory retrieval, we examined differences in functional brain network architecture between forgotten and remembered words. This study yielded three main findings. First, graph theory analyses showed that successfully remembering compared to forgetting was associated with significant changes in the connectivity profile of the left hippocampus and a corresponding increase in efficient communication with the rest of the brain. Second, bivariate functional connectivity analyses indicated stronger interactions between the left hippocampus and a retrieval assembly for remembered versus forgotten items. This assembly included the left precuneus, left caudate, bilateral supramarginal gyrus, and the bilateral dorsolateral superior frontal gyrus. Integrative properties of the retrieval assembly were greater for remembered than forgotten items. Third, whole‐brain modularity analyses revealed that successful memory retrieval was marginally significantly associated with a less segregated modular architecture in the network. The magnitude of the decreases in modularity between remembered and forgotten conditions was related to memory performance. These findings indicate that increases in integrative properties at the nodal, retrieval assembly, and whole‐brain topological levels facilitate memory retrieval, while also underscoring the potential of multivariate brain connectivity approaches for providing valuable new insights into the neural bases of memory processes. Hum Brain Mapp 38:2242–2259, 2017. © 2017 Wiley Periodicals, Inc.
Plasticity of neonatal neuronal networks in very premature infants: Source localization of temporal theta activity, the first endogenous neural biomarker, in temporoparietal areas
Authors: Routier L. , Mahmoudzadeh M. , Panzani M. , Azizollahi H. , Goudjil S. , Kongolo G. , Wallois F. 
Published: January 2017

AbstractTemporal theta slow‐wave activity (TTA‐SW) in premature infants is a specific signature of the early development of temporal networks, as it is observed at the turning point between non‐sensory driven spontaneous local processing and cortical network functioning. The role in development and the precise location of TTA‐SW remain unknown. Previous studies have demonstrated that preterms from 28 weeks of gestational age (wGA) are able to discriminate phonemes and voice, supporting the idea of a prior genetic structural or activity‐dependent fingerprint that would prepare the auditory network to compute auditory information at the onset of thalamocortical connectivity. They recorded TTA‐SW in 26–32 wGA preterms. The rate of TTA‐SW in response to click stimuli was evaluated using low‐density EEG in 30 preterms. The sources of TTA‐SW were localized by high‐density EEG using different tissues conductivities, head models and mathematical models. They observed that TTA‐SW is not sensory driven. Regardless of age, conductivities, head models and mathematical models, sources of TTA‐SW were located adjacent to auditory and temporal junction areas. These sources become situated closer to the surface during development. TTA‐SW corresponds to spontaneous transient endogenous activities independent of sensory information at this period which might participate in the implementation of auditory, language, memory, attention and or social cognition convergent and does not simply represent a general interaction between the subplate and the cortical plate. Hum Brain Mapp 38:2345–2358, 2017. © 2017 Wiley Periodicals, Inc.
Membrane remodeling and organization: Elements common to prokaryotes and eukaryotes
Authors: Vega‐Cabrera Luz A. , Pardo‐López Liliana 
Published: January 2017

AbstractMembrane remodeling processes in eukaryotes, such as those involved in endocytosis and intracellular trafficking, are mediated by a large number of structural, accessory and regulatory proteins. These processes occur in all cell types, enabling the exchange of signals and/or nutrients with the external medium and with neighboring cells; likewise, they are required for the intracellular trafficking of various cargo molecules between organelles, as well as the recycling of these structures. Recent studies have demonstrated that some elements of the molecular machinery involved in regulating and mediating endocytosis in eukaryotic cells are also present in some bacteria, where they participate in processes such as cell division, sporulation and signal transduction. However, the mechanism whereby this prokaryotic machinery carries out such functions has barely begun to be elucidated. This review summarizes recent information about the cytoskeletal and membrane‐organizing proteins for which bacterial homologs have been identified; given their known functions, they may be considered to be part of an ancestral membrane organization system that first emerged in prokaryotes and which further evolved into the more complex regulatory networks operating in eukaryotes. © 2017 IUBMB Life, 69(2):55–62, 2017