bluuebunny/crossref_metadata_2025 huggingface dataset:
EXPERIÊNCIAS ESCOLARES DE ESTUDANTES TRANS
Authors: Cruz Tania Mara , Dos Santos Tiago Zeferino
Published: May 2016

Este estudo busca resgatar memórias, enquanto estudantes, de duas transexuais femininas, assim autodefinidas, de Tubarão – SC, no intuito de analisar suas experiências escolares durante o paulatino processo de feminilização. Trata-se de pesquisa qualitativa, construída com recortes de histórias de vida na Educação Básica em escolas públicas e nas licenciaturas de História e de Letras em universidades privadas. A pesquisa empírica se deu a partir de entrevistas com roteiro semiestruturado, sendo analisada a partir dos pressupostos dos estudos de gênero e de educação. O contraditório espaço escolar apresentou-se como lugar de discriminação heterossexista, vigilante contra quem não se enquadrasse nos padrões binários e hegemônicos de gênero e de sexualidade. No entanto, devido ao suporte de colegas e da resistência das estudantes trans, tal contexto não as impediu de seguir estudando.
Acidentes de trabalho com exposição a material biológico: Descrição dos casos na Bahia
Authors: Cordeiro Técia Maria Santos Carneiro e , Carneiro Neto José Nunes , Cardoso Mariana De Castro Brandão , Santana Mattos Amália Ivine , Santos Kionna Oliveira Bernardes , Araújo Tânia Maria de
Published: May 2016

Justificativa e Objetivo: Este estudo se insere no campo da saúde pública brasileira, em específico da saúde do trabalhador, pelos acidentes de trabalho com exposição a material biológico consistir num agravo evitável. Desta forma, o objetivo foi descrever os fatores associados aos acidentes de trabalho com exposição a material biológico e as condutas adotadas pós-exposição dos casos notificadas no SINAN no estado da Bahia em 2012. Métodos: Trata-se de um estudo epidemiológico de caráter descritivo realizado com dados do SINAN em fevereiro de 2013, a análise foi realizada pela estatística descritiva em frequências absoluta e relativa. Resultados: Os resultados indicam uma maior ocorrência dos acidentes ocupacionais com exposição a materiais biológicos na Bahia na população feminina 78,1% e na faixa etária entre 30-49 anos 51,5%; o sangue foi o fluido de maior contato nos acidentes com 75,2% por meio da via percutânea 71,5%; as condutas adotadas pós-exposição foram de acordo o recomendado pelo Ministério da Saúde; várias informações não foram preenchidas nas notificações e apenas 23,8% de Comunicação de Acidente de Trabalho foram emitidas. Conclusão: Considera-se necessário a elaboração de estratégias acerca da saúde e segurança ocupacional, sensibilização dos trabalhadores sobre a relevância das condutas adotadas após os acidentes ocupacionais com exposição a material biológico e o treinamento dos profissionais para notificação dos casos e investigação com preenchimento de todos os campos da ficha de notificação e também da emissão da CAT.
Simple Logics for Basic Algebras
Authors: Cı̅rulis Ja̅nis
Published: May 2016

An MV-algebra is an algebra (A, ⊕, ¬, 0), where (A, ⊕, 0) is a commutative monoid and ¬ is an idempotent operation on A satisfying also some additional axioms. Basic algebras are similar algebras that can roughly be characterised as nonassociative (hence, also non-commutative) generalizations of MV-algebras. Basic algebras and commutative basic algebras provide an equivalent algebraic semantics in the sense of Blok and Pigozzi for two recent logical systems. Both are Hilbert-style systems, with implication and negation as the primitive connectives. We present a considerably simpler logic, Lʙ, for basic algebras, where implication and falsum are taken as primitives. We also consider some subvarieties of basic algebras known in the literature, discuss classes of implicational algebras term-equivalent to each of these varieties, and construct axiomatic extensions of Lʙ for which these classes serve as equivalent algebraic semantics.
On Halldén Completeness of Modal Logics Determined by Homogeneous Kripke Frames
Authors: Kostrzycka Zofia
Published: May 2016

Halldén complete modal logics are defined semantically. They have a nice characterization as they are determined by homogeneous Kripke frames.
Effects of breeding versus winter habitat loss and fragmentation on the population dynamics of a migratory songbird
Authors: Taylor Caz M. , Stutchbury Bridget J. M.
Published: May 2016

Many migratory species are in decline and understanding these declines is challenging because individuals occupy widely divergent and geographically distant habitats during a single year and therefore populations across the range are interconnected in complex ways. Network modeling has been used to show, theoretically, that shifts in migratory connectivity patterns can occur in response to habitat or climate changes and that habitat loss in one region can affect sub‐populations in regions that are not directly connected. Here, we use a network model, parameterized by integrating long‐term monitoring data with direct tracking of ~100 individuals, to explain population trends in the rapidly declining Wood Thrush (Hylocichla mustelina) and to predict future trends. Our model suggests that species‐level declines in Wood Thrush are driven primarily by tropical deforestation in Central America but that protection of breeding habitat in some regions is necessary to prevent shifts in migratory connectivity and to sustain populations in all breeding regions. The model illustrates how shifts in migratory connectivity may lead to unexpected population declines in key regions. We highlight current knowledge gaps that make modeling full life‐cycle population demographics in migratory species challenging but also demonstrate that modeling can inform conservation while these gaps are being filled.
Changes in horn size of Stone's sheep over four decades correlate with trophy hunting pressure
Authors: Douhard Mathieu , Festa‐Bianchet Marco , Pelletier Fanie , Gaillard Jean‐Michel , Bonenfant Christophe
Published: May 2016

Selective harvest may lead to rapid evolutionary change. For large herbivores, trophy hunting removes males with large horns. That artificial selection, operating in opposition to sexual selection, can lead to undesirable consequences for management and conservation. There have been no comparisons of long‐term changes in trophy size under contrasting harvest pressures. We analyzed horn measurements of Stone's rams (Ovis dalli stonei) harvested over 37 years in two large regions of British Columbia, Canada, with marked differences in hunting pressure to identify when selective hunting may cause a long‐term decrease in horn growth. Under strong selective harvest, horn growth early in life and the number of males harvested declined by 12% and 45%, respectively, over the study period. Horn shape also changed over time: horn length became shorter for a given base circumference, likely because horn base is not a direct target of hunter selection. In contrast, under relatively lower hunting pressure, there were no detectable temporal trends in early horn growth, number of males harvested, or horn length relative to base circumference. Trophy hunting is an important recreational activity and can generate substantial revenues for conservation. By providing a reproductive advantage to males with smaller horns and reducing the availability of desirable trophies, however, excessive harvest may have the undesirable long‐term consequences of reducing both the harvest and the horn size of rams. These consequences can be avoided by limiting offtake.
Effects of wetland plants on denitrification rates: a meta‐analysis
Authors: Alldred Mary , Baines Stephen B.
Published: May 2016

Human activity is accelerating changes in biotic communities worldwide. Predicting impacts of these changes on ecosystem services such as denitrification, a process that mitigates the consequences of nitrogen pollution, remains one of the most important challenges facing ecologists. Wetlands especially are valued as important sites of denitrification, and wetland plants are expected to have differing effects on denitrification. We present the results of a meta‐analysis, conducted on 419 published estimates of denitrification in wetlands dominated by different plant species. Plants increased denitrification rates by 55% on average. This effect varied significantly among communities as defined by the dominant plant species, but surprisingly did not differ substantially among methods for measuring denitrification or among types of wetlands. We conclude that mechanistically linking functional plant traits to denitrification will be key to predicting the role of wetlands in nitrogen mitigation in a changing world.
Restoration treatments in urban park forests drive long‐term changes in vegetation trajectories
Authors: Johnson Lea R. , Handel Steven N.
Published: May 2016

Municipalities are turning to ecological restoration of urban forests as a measure to improve air quality, ameliorate urban heat island effects, improve storm water infiltration, and provide other social and ecological benefits. However, community dynamics following urban forest restoration treatments are poorly documented. This study examines the long‐term effects of ecological restoration undertaken in New York City, New York, USA, to restore native forest in urban park natural areas invaded by woody non‐native plants that are regional problems. In 2009 and 2010, we sampled vegetation in 30 invaded sites in three large public parks that were restored 1988–1993, and 30 sites in three large parks that were similarly invaded but had not been restored. Data from these matched plots reveal that the restoration treatment achieved its central goals. After 15–20 years, invasive species removal followed by native tree planting resulted in persistent structural and compositional shifts, significantly lower invasive species abundance, a more complex forest structure, and greater native tree recruitment. Together, these findings indicate that successional trajectories of vegetation dynamics have diverged between restored forests and invaded forests that were not restored. In addition, the data suggest that future composition of these urban forest patches will be novel assemblages. Restored and untreated sites shared a suite of shade‐intolerant, quickly‐growing tree species that colonize disturbed sites, indicating that restoration treatments created sites hospitable for germination and growth of species adapted to high light conditions and disturbed soils. These findings yield an urban perspective on the use of succession theory in ecological restoration. Models of ecological restoration developed in more pristine environments must be modified for use in cities. By anticipating both urban disturbances and ecological succession, management of urban forest patches can be adjusted to better predict and direct long‐term outcomes. An urban approach to ecological restoration must use realistic, flexible targets to preserve and enhance urban biodiversity for both short‐term benefits and long‐term sustainability.
Can we control the invasive cane toad using chemicals that have evolved under intraspecific competition?
Authors: Clarke Gregory S. , Crossland Michael R. , Shine Richard
Published: May 2016

Many invasive species experience intense intraspecific competition, because they are abundant in anthropogenically disturbed habitats where few native species persist. Species‐specific competitive mechanisms that evolve in this context may offer novel, highly targeted means to control invasive taxa. We conducted laboratory experiments to evaluate the feasibility of this method of control, based on waterborne cues that are produced by tadpoles of the cane toad (Rhinella marina) to suppress the development of conspecific embryos. Our trials examined the nature and species‐specificity of the effect, the robustness of the cue to freezing and storage, and the amounts required to suppress toad embryos. Our results were encouraging. The cue appears to be chemical rather than a biological organism, and may well be species‐specific; the four species of native anurans that we tested were not influenced by toad larval cues. The cue retains its effectiveness after being frozen, but not after being dried, or after 7 d in water. It is effective at very low concentrations (the amount produced by three tadpoles within 750 L of water). Overall, the cane toad's suppressor pheromone may offer an effective new way to control invasive toads.
Pastoral and woodcutting activities drive Cedrus atlantica Mediterranean forest structure in the Moroccan Middle Atlas
Authors: Coudel Marc , Aubert Pierre‐Marie , Aderghal Mohammed , Hély Christelle
Published: May 2016

Human activities are historical ecological drivers, and we need to better understand their effects on ecosystems. In particular, they have been very important in the shaping of the Mediterranean biodiversity hotspot. Researchers and managers nonetheless lack knowledge concerning the impacts of their combinations and their current intensity on the structure of forest ecosystems of the southern part of the Mediterranean basin. In this study, we have develped a new methodology in order to understand the impacts of combined pastoral and woodcutting activities on the forest structure of the still ill‐described but ecologically and economically important Moroccan Middle Atlas cedar forests. In a 40 000 ha forest, we chose 103 sites and sampled human activities through proxies and forest structures through circumference and vertical structures. A typology of sites yielded four human activity types: dominant pastoral activities, dominant oak cutting or cedar cutting activities, and an intermediate mid‐disturbance type. This typology did not depend on altitude or substrate, confirming that the ecosystem structures linked to the different types depend more on human activities than on main environmental parameters. Pastoral activities modified forests the most, converting them to parklands with reduced canopies and low dynamics but high tree maturation. Woodcutting activities induced gap dynamics, favoring Cedrus atlantica in favorable environmental conditions and Quercus ilex otherwise, while they affected vertical structure depending on the local environment and competition for light and soil resources. Moderately disturbed stands showed forest maturation with low competition for light. Unlike previous studies, we found no evidence of a general degradation of cedar forests due to local human activities. However, cedar logging has reduced standing basal area regionally and one third of the sites may have vulnerable cedar populations due to pastoral activities and to unfavorable environmental conditions. These results can direct future research and management needs for a better protection of Mediterranean forests and parklands and their biodiversity, although to be effective such efforts must also partner with sociogeographical studies.
Carbon sources and trophic relationships of ice seals during recent environmental shifts in the Bering Sea
Authors: Wang Shiway W. , Springer Alan M. , Budge Suzanne M. , Horstmann Lara , Quakenbush Lori T. , Wooller Matthew J.
Published: May 2016

Dramatic multiyear fluctuations in water temperature and seasonal sea ice extent and duration across the Bering–Chukchi continental shelf have occurred in this century, raising a pressing ecological question: Do such environmental changes alter marine production processes linking primary producers to upper trophic‐level predators? We examined this question by comparing the blubber fatty acid (FA) composition and stable carbon isotope ratios of individual FA (δ13CFA) of adult ringed seals (Pusa hispida), bearded seals (Erignathus barbatus), spotted seals (Phoca largha), and ribbon seals (Histriophoca fasciata), collectively known as “ice seals,” sampled during an anomalously warm, low sea ice period in 2002–2005 in the Bering Sea and a subsequent cold, high sea ice period in 2007–2010. δ13CFAvalues, used to estimate the contribution to seals of carbon derived from sea ice algae (sympagic production) relative to that derived from water column phytoplankton (pelagic production), indicated that during the cold period, sympagic production accounted for 62–80% of the FA in the blubber of bearded seals, 51–62% in spotted seals, and 21–60% in ringed seals. Moreover, the δ13CFAvalues of bearded seals indicated a greater incorporation of sympagic FAs during the cold period than the warm period. This result provides the first empirical evidence of an ecosystem‐scale effect of a putative change in sympagic production in the Western Arctic. The FA composition of ice seals showed clear evidence of resource partitioning among ringed, bearded, and spotted seals, and little niche separation between spotted and ribbon seals, which is consistent with previous studies. Despite interannual variability, the FA composition of ringed and bearded seals showed little evidence of differences in diet between the warm and cold periods. The findings that sympagic production contributes significantly to food webs supporting ice seals, and that the contribution apparently is less in warm years with low sea ice, raise an important concern: Will the projected warming and continuing loss of seasonal sea ice in the Arctic, and the associated decline of organic matter input from sympagic production, be compensated for by pelagic production to satisfy both pelagic and benthic carbon and energy needs?
Characterizing forest structure variations across an intact tropical peat dome using field samplings and airborne LiDAR
Authors: Nguyen Ha T. , Hutyra Lucy R. , Hardiman Brady S. , Raciti Steve M.
Published: May 2016

Tropical peat swamp forests (PSF) are one of the most carbon dense ecosystems on the globe and are experiencing substantial natural and anthropogenic disturbances. In this study, we combined direct field sampling and airborne LiDAR to empirically quantify forest structure and aboveground live biomass (AGB) across a large, intact tropical peat dome in Northwestern Borneo. Moving up a 4 m elevational gradient, we observed increasing stem density but decreasing canopy height, crown area, and crown roughness. These findings were consistent with hypotheses that nutrient and hydrological dynamics co‐influence forest structure and stature of the canopy individuals, leading to reduced productivity towards the dome interior. Gap frequency as a function of gap size followed a power law distribution with a shape factor (λ) of 1.76 ± 0.06. Ground‐based and dome‐wide estimates of AGB were 217.7 ± 28.3 Mg C/ha and 222.4 ± 24.4 Mg C/ha, respectively, which were higher than previously reported AGB for PSF and tropical forests in general. However, dome‐wide AGB estimates were based on height statistics, and we found the coefficient of variation on canopy height was only 0.08, three times less than stem diameter measurements, suggesting LiDAR height metrics may not be a robust predictor of AGB in tall tropical forests with dense canopies. Our structural characterization of this ecosystem advances the understanding of the ecology of intact tropical peat domes and factors that influence biomass density and landscape‐scale spatial variation. This ecological understanding is essential to improve estimates of forest carbon density and its spatial distribution in PSF and to effectively model the effects of disturbance and deforestation in these carbon dense ecosystems.
Placing invasive species management in a spatiotemporal context
Authors: Baker Christopher M. , Bode Michael
Published: May 2016

Invasive species are a worldwide issue, both ecologically and economically. A large body of work focuses on various aspects of invasive species control, including how to allocate control efforts to eradicate an invasive population as cost effectively as possible. There are a diverse range of invasive species management problems, and past mathematical analyses generally focus on isolated examples, making it hard to identify and understand parallels between the different contexts. In this study, we use a single spatiotemporal model to tackle the problem of allocating control effort for invasive species when suppressing an island invasive species, and for long‐term spatial suppression projects. Using feral cat suppression as an illustrative example, we identify the optimal resource allocation for island and mainland suppression projects. Our results demonstrate how using a single model to solve different problems reveals similar characteristics of the solutions in different scenarios. As well as illustrating the insights offered by linking problems through a spatiotemporal model, we also derive novel and practically applicable results for our case studies. For temporal suppression projects on islands, we find that lengthy projects are more cost effective and that rapid control projects are only economically cost effective when population growth rates are high or diminishing returns on control effort are low. When suppressing invasive species around conservation assets (e.g., national parks or exclusion fences), we find that the size of buffer zones should depend on the ratio of the species growth and spread rate.
Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States
Authors: Carver Scott , Bevins Sarah N. , Lappin Michael R. , Boydston Erin E. , Lyren Lisa M. , Alldredge Mathew , Logan Kenneth A. , Sweanor Linda L. , Riley Seth P. D. , Serieys Laurel E. K. , Fisher Robert N. , Vickers T. Winston , Boyce Walter , McBride Roy , Cunningham Mark C. , Jennings Megan , Lewis Jesse , Lunn Tamika , Crooks Kevin R. , VandeWoude Sue
Published: May 2016

Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened >1000 samples from sympatric populations of puma (Pumaconcolor), bobcat (Lynxrufus), and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal, and viral pathogens (Bartonellasp.,Toxoplasma gondii, feline herpesvirus‐1, feline panleukopenea virus, feline calicivirus, and feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure; providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely divergent between the wild felid species. For puma, suburban land use predicted increased exposure toBartonellasp. in southern California, andFHV‐1 exposure increased near urban edges in Florida. This may suggest interspecific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure toT. gondiiin Florida, suggesting an urban source of prey. Bobcats captured near urban areas in Colorado and Florida had higherFIVexposure, possibly suggesting increased intraspecific interactions through pile‐up of home ranges. Beyond these regional and pathogen specific relationships, proximity to the wildland–urban interface did not generally increase the probability of disease exposure in wild or domestic felids, emphasizing the importance of local ecological determinants. Indeed, pathogen exposure was often negatively associated with the wildland–urban interface for all felids. Our analyses suggest cross‐species pathogen transmission events around this interface may be infrequent, but followed by self‐sustaining propagation within the new host species.
Maintaining animal assemblages through single‐species management: the case of threatened caribou in boreal forest
Authors: Bichet Orphé , Dupuch Angélique , Hébert Christian , Le Borgne Hélène , Fortin Daniel
Published: May 2016

With the intensification of human activities, preserving animal populations is a contemporary challenge of critical importance. In this context, the umbrella species concept is appealing because preserving a single species should result in the protection of multiple co‐occurring species. Practitioners, though, face the task of having to find suitable umbrellas to develop single‐species management guidelines. In North America, boreal forests must be managed to facilitate the recovery of the threatened boreal caribou (Rangifer tarandus). Yet, the effect of caribou conservation on co‐occurring animal species remains poorly documented. We tested if boreal caribou can constitute an effective umbrella for boreal fauna. Birds, small mammals, and insects were sampled along gradients of post‐harvest and post‐fire forest succession. Predictive models of occupancy were developed from the responses of 95 species to characteristics of forest stands and their surroundings. We then assessed the similarity of species occupancy expected between simulated harvested landscapes and a 90 000‐km2 uncut landscape. Managed landscapes were simulated based on three levels of disturbance, two timber‐harvest rotation cycles, and dispersed or aggregated cut‐blocks. We found that management guidelines that were more likely to maintain caribou populations should also better preserve animal assemblages. Relative to fragmentation or harvest cycle, we detected a stronger effect of habitat loss on species assemblages. Disturbing 22%, 35%, and 45% of the landscape should result, respectively, in 80%, 60%, and 40% probability for caribou populations to be sustainable; in turn, this should result in regional species assemblages with Jaccard similarity indices of 0.86, 0.79, and 0.74, respectively, relative to the uncut landscape. Our study thus demonstrates the value of single‐species management for animal conservation. Our quantitative approach allows for the evaluation of management guidelines prior to implementation, thereby providing a tool for establishing suitable compromises between economic and environmental sustainability of human activities.
Chronic nitrogen deposition alters tree allometric relationships: implications for biomass production and carbon storage
Authors: Ibáñez Inés , Zak Donald R. , Burton Andrew J. , Pregitzer Kurt S.
Published: May 2016

As increasing levels of nitrogen (N) deposition impact many terrestrial ecosystems, understanding the potential effects of higher N availability is critical for forecasting tree carbon allocation patterns and thus future forest productivity. Most regional estimates of forest biomass apply allometric equations, with parameters estimated from a limited number of studies, to forest inventory data (i.e., tree diameter). However, most of these allometric equations cannot account for potential effects of increased N availability on biomass allocation patterns. Using 18 yr of tree diameter, height, and mortality data collected for a dominant tree species (Acer saccharum) in an atmospheric N deposition experiment, we evaluated how greater N availability affects allometric relationships in this species. After taking into account site and individual variability, our results reveal significant differences in allometric parameters between ambient and experimental N deposition treatments. Large trees under experimental N deposition reached greater heights at a given diameter; moreover, their estimated maximum height (mean ± standard deviation: 33.7 ± 0.38 m) was significantly higher than that estimated under the ambient condition (31.3 ± 0.31 m). Within small tree sizes (5–10 cm diameter) there was greater mortality under experimental N deposition, whereas the relative growth rates of small trees were greater under experimental N deposition. Calculations of stemwood biomass using our parameter estimates for the diameter–height relationship indicated the potential for significant biases in these estimates (~2.5%), with under predictions of stemwood biomass averaging 4 Mg/ha lower if ambient parameters were to be used to estimate stem biomass of trees in the experimental N deposition treatment. As atmospheric N deposition continues to increase into the future, ignoring changes in tree allometry will contribute to the uncertainty associated with aboveground carbon storage estimates across a forest with a large geographic distribution in eastern North America.
Environmental heterogeneity has a weak effect on diversity during community assembly in tallgrass prairie
Authors: Baer Sara G. , Blair John M. , Collins Scott L.
Published: May 2016

Abstract

Understanding what constrains the persistence of species in communities is at the heart of community assembly theory and its application to conserving and enhancing biodiversity. The “environmental heterogeneity hypothesis” predicts greater species coexistence in habitats with greater resource variability. In the context of community assembly, environmental heterogeneity may influence the variety and strength of abiotic conditions and competitive interactions (environmental filters) to affect the relative abundance of species and biodiversity. We manipulated key resources that influence plant diversity in tallgrass prairie (i.e., soil depth and nitrogen availability) to increase environmental heterogeneity prior to sowing native prairie species into a former agricultural field. We compared variability in nutrient availability, aboveground annual net primary productivity (ANPP), and the composition of species between replicate plots containing soil heterogeneity manipulations and plots with no resource manipulations (n = 4 per treatment) during the first 15 yr of community assembly as a test of the “environmental heterogeneity hypothesis.” The manipulations increased environmental heterogeneity, measured as the coefficient of variation in NO3‐N availability and ANPP. Plant diversity, however, was similar and decayed exponentially and indiscriminately over time between the heterogeneity treatments. Species richness declined linearly over time in both heterogeneity treatments, but richness was higher in the more heterogeneous soil 2 yr following a second propagule addition 8 yr after the initial sowing. As a result, there was a lower rate of species loss over time in the more heterogeneous soil (0.60 species yr−1) relative to the control soil (0.96 species yr−1). Communities in each treatment exhibited strong convergence over time resulting from a shift in dominant species across all treatments and a gradual increase in the clonal C4 grass, Andropogon gerardii. We attribute the weak effect of heterogeneity on diversity to increasing dominance of a clonal species, which decreased the scale of soil treatments relative to plant size, dispersal limitation, and absence of a key driver (grazing) known to increase plant diversity under a frequent fire regime. Thus, steering community assembly to attain high biodiversity may depend more on manipulating processes that reduce dominance and facilitate the arrival of new species than promoting environmental heterogeneity.
Identification of migratory bird flyways in North America using community detection on biological networks
Authors: Buhnerkempe Michael G. , Webb Colleen T. , Merton Andrew A. , Buhnerkempe John E. , Givens Geof H. , Miller Ryan S. , Hoeting Jennifer A.
Published: May 2016

Migratory behavior of waterfowl populations in North America has traditionally been broadly characterized by four north–south flyways, and these flyways have been central to the management of waterfowl populations for more than 80 yr. However, previous flyway characterizations are not easily updated with current bird movement data and fail to provide assessments of the importance of specific geographical regions to the identification of flyways. Here, we developed a network model of migratory movement for four waterfowl species, Mallard (Anas platyrhnchos), Northern Pintail (A. acuta), American Green‐winged Teal (A. carolinensis), and Canada Goose (Branta canadensis), in North America, using bird band and recovery data. We then identified migratory flyways using a community detection algorithm and characterized the importance of smaller geographic regions in identifying flyways using a novel metric, the consolidation factor. We identified four main flyways for Mallards, Northern Pintails, and American Green‐winged Teal, with the flyway identification in Canada Geese exhibiting higher complexity. For Mallards, flyways were relatively consistent through time. However, consolidation factors revealed that for Mallards and Green‐winged Teal, the presumptive Mississippi flyway was potentially a zone of high mixing between other flyways. Our results demonstrate that the network approach provides a robust method for flyway identification that is widely applicable given the relatively minimal data requirements and is easily updated with future movement data to reflect changes in flyway definitions and management goals.
Periodontal Wound Healing by Transplantation of Jaw Bone Marrow‐Derived Mesenchymal Stem Cells in Chitosan/Anorganic Bovine Bone Carrier Into One‐Wall Infrabony Defects in Beagles
Authors: Zang Shengqi , Jin Lei , Kang Shuai , Hu Xin , Wang Meng , Wang Jinjin , Chen Bo , Peng Bo , Wang Qintao
Published: May 2016

Background: This study aims to evaluate the performance of chitosan/anorganic bovine bone (C/ABB) scaffold seeded with human jaw bone marrow‐derived mesenchymal stem cells (hJBMMSCs) in supporting the healing/repair of 1‐wall critical‐size periodontal defects.

Methods: Physical properties of the C/ABB scaffold were compared with those of the chitosan scaffold. hJBMMSCs were obtained from healthy human alveolar bone during the extraction of third molar impacted teeth. One‐wall (7 × 4 mm) infrabony defects were surgically created at the bilateral mandibular third premolars and first molars in six beagles. The defects were randomly assigned to six groups and implanted with different scaffolds: 1) chitosan (C) scaffold; 2) C scaffold with hJBMMSCs (C + cell); 3) C/ABB scaffold (C/ABB); 4) C/ABB scaffold with hJBMMSCs (C/ABB + cell); 5) ABB scaffold (ABB); and 6) open flap debridement (control). The animals were euthanized 8 weeks after surgery for histologic analysis.

Results: The C/ABB scaffold had a porous structure and increased compressive strength. Both C/ABB and C/ABB + cell exhibited the newly formed cellular mixed‐fiber cementum, woven/lamellar bone, and periodontal ligament. Cementum formation was significantly greater in group C/ABB + cell than in group C/ABB (2.64 ± 0.50 mm versus 0.91 ± 0.55 mm, P <0.05). For new bone (NB) height, group C/ABB + cell and C/ABB showed mean ± SD values of 2.83 ± 0.29 mm and 2.65 ± 0.52 mm and for NB area 8.89 ± 1.65 mm and 8.73 ± 1.94 mm2, respectively. For NB (height and area), there was no significant difference between the two groups.

Conclusions: The combination of hJBMMSCs and C/ABB scaffolds could promote periodontal repair. Future studies are expected to further optimize the combination and lead to an ideal periodontal regeneration.
New insight of sedimentological and geochemical characterization of siliciclastic-carbonate deposits (Alveolina Limestone Formation, Graus-Tremp basin, Spain)
Authors: Hamon Youri , Deschamps Remy , Joseph Philippe , Garcia Daniel , Chanvry Emmanuelle
Published: May 2016

This article is a first attempt of combining sedimentological analysis and geochemical systematics of the Alveolina Limestone Formation as a tool to identify the major stratigraphic surfaces, and to improve the sequence stratigraphy interpretation. This formation is Early Eocene in age and crops out in several well-exposed cliffs in the Serraduy – Roda de Isabena area (Graus-Tremp basin, NE Spain). Within this succession, nineteen carbonate and siliciclastic facies have been identified and grouped in environmental facies associations (based on their vertical stacking and lateral relationships): 1) coastal plain; 2) clastic deltaic complex; 3) shallow carbonate inner-ramp; 4) mid-ramp; 5) outer-ramp; 6) reefal facies. The depositional architectures studied in the Serraduy area can be directly assessed on the field, and a 3D reconstruction is proposed. This enables us to build a synthetic depositional model and to identify five small-scale T/R cycles, bounded by different kinds of sedimentary discontinuities : angular unconformity, firmground, erosional surface… In parallel, geochemical analyses (C and O isotopes, major, minor and trace elements) were carried out to help at hierarchizing the cycles and the boundaries previously identified. Four of them may be considered as major stratigraphic surfaces, corresponding either to regional-scale angular unconformities, or to exposure surfaces. The latter are characterized by a selective dissolution, a slight but sharp decrease in δ13CV-PDB and in Mg, Fe and Sr contents below the surface. The absence of typical sedimentary criteria of exposure (with the exception of these geochemical signatures) may be explained by short-term exposure, an arid to semi-arid climate, and a dominant low-magnesian calcite original mineralogy, precluding the development and the preservation of widespread vadose diagenetic products. A new sequence stratigraphy model for the Alveolina Limestone Fm is finally proposed and discussed.
The Atlas-Meseta Red Beds basin (Morocco) and the Lower Ordovician rifting of NW-Gondwana
Authors: Ouanaimi Hassan , Soulaimani Abderrahmane , Hoepffner Christian , Michard André , Baidder Lahssen
Published: May 2016

The transition from the Cambrian to Ordovician in Morocco is known to be characterized by a frequent Furongian hiatus, restricted extension of the Tremadocian marine deposits, and frequent unconformities at the base of the transgressive upper Floian deposits. In the present work, we first highlight the occurrence of Fe- and mica-rich, red silty/sandy formations in the Central and Eastern High Atlas between the Middle Cambrian and Upper Floian sequences. In the Tislyt type-locality, a synsedimentary hemigraben structure is defined, within which the red beds show frequent slump folds, debris flows and internal unconformities. The correlation with several coeval series of the Meseta domain allows us to define a shallow marine, ferruginous clastic Atlas-Meseta Red Beds (AMRB) basin during the Tremadocian-early Floian. The AMRB basin extended between the Meseta coastal block and the Anti-Atlas domain, being limited by the fault zones that became the West Meseta shear zone and the South Meseta fault, respectively, in the Variscan orogen. The AMRB basin compares with the coeval rifted basins of the central Iberian and Armorican massifs. The red beds were likely sourced from the east, from both the Precambrian basement and Early Ordovician magmatic rocks, contrary to the Ordovician deposits of the Sahara platform sourced from the south. Subsidence of the AMRB and central Iberian-Armorican basins of the NW-Gondwana border aborted during the Floian, whereas the opening of the Rheic ocean went on more to the west.
Targeting and mapping expansive soils (Loiret, France): geometrical analysis of laboratory soil spectra in the short-wave infrared domain (1100–2500 nm)
Authors: Dufréchou Grégory , Hohmann Audrey , Bourguignon Anne , Grandjean Gilles
Published: May 2016

Short-wave infrared (SWIR: 1100–2500 nm) reflectance spectra of soil samples, acquired under laboratory-controlled conditions, were used to estimate the swelling potentials of the soils and to use SWIR spectroscopy to improve a part of the swelling-risk map of France. A total of 332 samples were collected to the west of Orléans (France) in various geological formations and swelling-risk areas and along two (eastern and western) transects with different samples spacings. Comparisons between the swelling potentials of the soils and the swelling-risk areas of the map exhibit good correlation in the south of the sampling area; however, there are several inconsistencies in the north of the study area that highlight the necessity of locally redrawing the accepted swelling-risk map of France. The sampling interval (approximately 260 m) along the eastern transect was too sparse and does not appear to have effectively captured the smallest and/or isolated lithologies. The sampling interval along the western transect (approximately 50 m) revealed the presence of an unmapped swelling-potential zone, which was confirmed by several soil samples. The sample interval along the western transect appears to be more suitable for mapping the smallest lithologies. The presence of several samples in close proximity that exhibit the same swelling potential is a robust indication of the presence of a zone with constant swelling potential. A new swelling-risk map of the sampling area was produced based on the soil samples. The map produced by interpolation did not permit the representation of discrete lithological units, introduced spurious swelling-risk zones that however could be representative of tillage in agricultural zones. More samples are therefore needed to produce a reliable map on the scale of the sampling area. According to swelling potential uncertainty related to soil sampling and soil treatment, spectroscopy-based approach proposed here cannot be used to replace the existing swelling-risk map of France. This method permits however the rapid and low-cost estimation of the swell potentials of a large number of samples, which could be used at regional-scale to target areas where doubt remains or where infrastructure damages attributed to swelling behavior are known. At local scale, soil samples need to be properly and laboratory treated to accurately produce local revised and detailed swelling-risk maps.
Controlled Release Urea Improved Nitrogen Use Efficiency and Yield of Wheat and Corn
Authors: Geng Jibiao , Chen Jianqiu , Sun Yunbao , Zheng Wenkui , Tian Xiaofei , Yang Yuechao , Li Chengliang , Zhang Min
Published: May 2016

Nitrogen fertilizer is important for improving wheat (Triticum aestivum L.) and corn (Zea mays L.) yields, but inappropriate application methods and excessive amounts lead to low N use efficiency and high N losses through leaching. To investigate the effects of controlled‐release urea (CRU) on crop yield and soil fertility, a field experiment was conducted from 2012 to 2014 in China. The 100% (180 kg ha−1) and 70% (126 kg ha−1) of the local practice N rates with CRU and urea were used. The results revealed that the release curves of CRU in the natural field corresponded well to the N requirements of wheat and corn plants, and a positive linear correlation was observed between release rates and days after buried in soil. Consequently, the CRU treatments achieved significantly higher wheat and corn yield by 8 to 12% and 9 to 11%, respectively, compared with urea treatments at the same N rate. Reducing N rate of CRU by 30% produced the same yield as with the 100% N rate of urea. The agronomic nitrogen use efficiency (NUE) was significantly increased and the leaching of soil N was reduced by CRU. The acidification rates and leaching of exchangeable Ca2+, K+, Na+ contents were reduced, base saturation and available P improved by application of CRU compared with urea. Therefore, the results suggested that a 30% decrease of CRU in the recommended application rate of N, can be an effective measure to save consumption input of N fertilizer.

Core Ideas

Nitrogen release rates of controlled‐release urea in field condition corresponded well to the N uptake of crop plants.

A 30% decrease in the application rate of N is possible with controlled‐release urea compared to urea.

The application of controlled‐release urea increased crop yield, N use efficiency, net farm profit, and soil fertility.
Climate and Management Factors Influence Soybean Yield Potential in a Subtropical Environment
Authors: Zanon Alencar Junior , Streck Nereu Augusto , Grassini Patricio
Published: May 2016

The interactive influence of climate and management factors on soybean [Glycine max (L.) Merr.] yield potential has not been investigated in subtropical production environments. Such information can help fine tune current soybean management practices to increase yield and resource‐use efficiency and to minimize risk. The objective of this study was to identify key biophysical and management factors governing variation in soybean yield potential in southern Brazil. To accomplish that objective, we used a large database on soybean yield and phenology collected from a combination of on‐farm and research‐station experiments conducted during four crop growing seasons (2011–2015) in Rio Grande do Sul (southern Brazil). The database portrayed a wide range of weather conditions, soil types, water regimes, sowing dates, and cultivar maturity groups (MGs). Water supply and photothermal quotient explained most of yield variation across site‐years. A boundary function was derived for the relationship between soybean yield and water supply, and an attainable water productivity of 9.1 kg grain ha−1 mm−1. A seasonal water supply of ∼800 mm appeared sufficient to maximize seed yield, and most late‐sown crops fell short of this value. Late‐sown crops were also exposed to a lower photothermal quotient during reproductive stages, and this explained the yield penalty of 26 kg ha−1 d−1 of sowing delay after 4 November observed for non‐water‐limited crops. Sowing date, accompanied by proper selection of cultivar MG and determination of soil water status at sowing time, appear to be the most cost‐effective management practices to ensure a high photothermal quotient and low risk of water deficit during reproductive stages and, therefore, a high yield potential in the subtropical environment of southern Brazil.

Core Ideas

Water supply and photothermal quotient explained most yield variation across site‐years.

A seasonal water supply of ∼800 mm appeared sufficient to maximize seed yield.

Sowing delay after 4 Nov. decreased yield potential by 26 kg ha−1 d−1.
Nutritional and Environmental Effects on Ammonia Emissions from Dairy Cattle Housing: A Meta‐Analysis
Authors: Bougouin Adeline , Leytem April , Dijkstra Jan , Dungan Robert S. , Kebreab Ermias
Published: May 2016

Nitrogen excreted in dairy manure can be potentially transformed and emitted as NH3, which can create livestock and human respiratory problems and be an indirect source of N2O. The objectives of this study were to: (i) investigate environmental factors influencing NH3 emissions from dairy housing; and (ii) identify key explanatory variables in the NH3 emissions prediction from dairy housing using a meta‐analytical approach. Data from 25 studies were used for the preliminary analysis, and data from 10 studies reporting 87 treatment means were used for the meta‐analysis. Season and flooring type significantly affected NH3 emissions. For nutritional effect analysis, the between‐study variability (heterogeneity) of mean NH3 emission was estimated using random‐effect models and had a significant effect (P < 0.01). Therefore, random‐effect models were extended to mixed‐effect models to explain heterogeneity regarding the available dietary and animal variables. The final mixed‐effect model included milk yield, dietary crude protein, and dry matter intake separately, explaining 45.5% of NH3 emissions heterogeneity. A unit increase in milk yield (kg d−1) resulted in a 4.9 g cow−1 d−1 reduction in NH3 emissions, and a unit increase in dietary crude protein content (%) and dry matter intake (kg d−1) resulted in 10.2 and 16.3 g cow−1 d−1 increases in NH3 emissions, respectively, in the scope of this study. These results can be further used to help identify mitigation strategies to reduce NH3 emissions from dairy housing by developing predictive models that could determine variables with strong association with NH3 emissions.

Core Ideas

Season and flooring type significantly affected NH3 emission rates.

Open lots had the highest emissions in this study but the lowest by USEPA.

Crude protein and dry matter intake had positive impacts on NH3 emissions.

Milk yield had negative impacts on NH3 emissions.