bluuebunny/crossref_metadata_2025_split huggingface dataset:
Des points fixes communs pour des difféomorphismes de qui commutent et préservent une mesure de probabilité
Authors: Béguin F. , Le Calvez P. , Firmo S. , Miernowski T. 
Published: February 2013

RésuméNous montrons des résultats d’existence de points fixes communs pour des homéomorphismes du plan ${ \mathbb{R} }^{2} $ ou la sphère ${ \mathbb{S} }^{2} $, qui commutent deux à deux et préservent une mesure de probabilité. Par exemple, nous montrons que des ${C}^{1} $-difféomorphismes ${f}_{1} , \ldots , {f}_{n} $ de ${ \mathbb{S} }^{2} $ suffisamment proches de l’identité, qui commutent deux à deux, et qui préservent une mesure de probabilité dont le support n’est pas réduit à un point, ont au moins deux points fixes communs.
Heat Shock Protein 70 (HSP70) Responses in Tissues of White Sturgeon and Green Sturgeon Exposed to Different Stressors
Authors: Wang Weifang , Deng Dong-Fang , De Riu Nicola , Moniello Giuseppe , Hung Silas S O 
Published: February 2013

Abstract
A factorial experiment was conducted to compare the responses of heat shock protein 70 (Hsp70) in seven different tissues of White Sturgeon Acipenser transmontanus and Green Sturgeon A. medirostris after they were exposed to four different stressors. Three White Sturgeon (2.3 ± 0.1 kg [mean ± SE]) and three Green Sturgeon (2.3 ± 0.1 kg [mean ± SE]) were each subjected to one of four different stressors, after which the Hsp70 levels in seven different tissues were measured using Western blot. The four stressors were heat shock, cold shock, air exposure, and food deprivation; and the seven tissues sampled were mucus, heart, liver, gastrointestinal tract, gill, spleen, and white muscle. We also sampled tissues of three White Sturgeon and three Green Sturgeon without any stressor, and measured their Hsp70 levels as a control. We compared Hsp70 responses of the stressed sturgeon with those of the control, which was set at 100%, and found that Hsp70 responses were significantly (P &lt; 0.05) affected by the different stressors and also varied significantly among the tissues. For both species of sturgeon, heat shock was shown to be the most effective stressor inducing Hsp70 responses and mucus was the most responsive tissue. Under heat shock stress, Hsp70 responses in all tissues except liver were significantly higher in the White Sturgeon than in the Green Sturgeon. When both species of fish were exposed to heat shock, cold shock, or food deprivation, White Sturgeon showed significantly higher Hsp70 responses in mucus than did Green Sturgeon. In summary, heat shock elicited the highest Hsp70 responses and mucus was the most sensitive tissue. Based on the tissue Hsp70 responses, White Sturgeon were predicted to have a better defense mechanism against heat shock than Green Sturgeon.
Characterization of Bacteria Isolated from Landlocked Fall Chinook Salmon Eggs from Lake Oahe, South Dakota
Authors: Bergmann David J , Brakke Alicia , Barnes Michael E 
Published: February 2013

Abstract
Bacteria were isolated from the eggs of landlocked fall Chinook Salmon Oncorhynchus tshawytscha prior to initial placement in vertical-flow incubations trays 4 h after spawning and also 27 d later at the early eyed egg stage of development. Bacterial densities on the eggs after iodophor disinfection and just before being placed in trays were very low, and most isolates were gram-positive, nonfermenting cocci. In contrast, bacterial densities on eggs at incubation day 27 exceeded 1 × 107 CFU/egg and were dominated by slow-growing, gram-negative coccobacilli. Pseudomonas spp., as well as Flavobacterium (closely related to F. johnsoniae) were also present. Most Pseudomonas and Flavobacterium isolates produced extracellular proteases, making them candidates for further investigation into their possible contribution to egg mortality.
Reproductive Biology of Pacific Ocean Perch in the Gulf of Alaska
Authors: Conrath Christina L. , Knoth Brian 
Published: February 2013

Abstract
Despite the ecological and economic importance of rockfish fisheries in Alaska waters, little information is available concerning the reproductive biology of the majority of federally managed rockfish species in the Gulf of Alaska. Pacific Ocean Perch Sebastes alutus are the most abundant and commercially important rockfish in this region. This study examines the reproductive biology of Pacific Ocean Perch within the Gulf of Alaska, utilizing histological techniques to microscopically examine ovarian tissue. Pacific Ocean Perch samples were obtained throughout the year during National Marine Fisheries Service and Alaska Department of Fish and Game scientific surveys, as well as scientific charters. Ovaries of Pacific Ocean Perch began to ripen during the month of August with yolk increasing until February. Embryos appeared within the ovaries during February and continued to grow and develop until parturition in May. Results from this study indicate the fork length at 50% maturity is 33.4 cm and the age at 50% maturity is 8.4 years. Both of these values are smaller than those currently utilized in the stock assessment of Gulf of Alaska Pacific Ocean Perch. Results from this study will improve the stock assessment of this species by providing more accurate estimates of reproductive parameters and reducing the uncertainty in estimates of length and age at maturity.
Received July 30, 2012; accepted November 16, 2012
Food Deserts and Childhood Obesity
Authors: Alviola Pedro A. , Nayga Rodolfo M. , Thomsen Michael 
Published: February 2013

AbstractWe utilize a panel data set from 2007 to 2009 on the state of Arkansas to identify and determine the effect of food deserts on school district obesity rates. We define food deserts as low‐income areas with limited food access. Using both classical panel data models and spatial error models, we find no statistically significant relationship between school district obesity rates and the existence of food deserts in Arkansas. This finding is consistent across different model specifications, in spatial, panel or cross‐sectional analysis, and with or without urban school districts in the data.
An Alternative to Developing Stores in Food Deserts: Can Changes in SNAP Benefits Make a Difference?
Authors: Andrews Margaret , Bhatta Rhea , Ploeg Michele Ver 
Published: February 2013

AbstractIn the search for policies to reduce the effects of limited food access, little consideration has been given to how economic incentives could be used to make it easier for low‐income families to access existing healthy food retailers. Using county‐level, administrative data on redemption of Supplemental Nutrition Assistance Program (SNAP) benefits by store type from May 2007 to May 2010, this paper investigates aggregate responses of SNAP participants to economic and policy changes. Results show that SNAP benefit increases, in general, are associated with a greater percentage of redemptions at superstores. However, other circumstances associated with the large increase in benefits enacted in April 2009 as a part of the stimulus bill reverse the positive effect. Estimates are stable across a number of specifications that also control for gas prices, store‐type density, local unemployment and state policies. Results suggest that economic incentives deserve further consideration as an alternative to store development in food desert communities.
Integrating Educational, Environmental, and Behavioral Economic Strategies May Improve the Effectiveness of Obesity Interventions
Authors: Gittelsohn Joel , Lee Katherine 
Published: February 2013

AbstractInterventions that change the food environment, provide nutrition education, and employ behavioral economics strategies can potentially contribute to healthier diets and reduce the risk of chronic disease, but no attempt has been made to integrate these into the same conceptual framework. We present case studies of three multilevel, integrated interventions implemented by Johns Hopkins University between 2004–2011. We develop a conceptual model based on these case studies. Interventions and policies should effectively maximize opportunities to nudge healthier behaviors. We believe that the integration of educational, environmental, and behavioral economic strategies will balance the strengths and limitations of each approach.
Demand Reduction from Plain and Pictorial Cigarette Warning Labels: Evidence from Experimental Auctions
Authors: Rousu Matthew C. , Thrasher James F. 
Published: February 2013

AbstractWe report the results of experimental auctions with U.S. smokers, assessing the percentage of U.S. smokers whose demand for cigarettes decreases when bidding on packs with text and pictorial warnings, relative to packs with text‐only warnings. We find that pictorial labels and pictorial labels accompanied by plain packaging are more effective at reducing demand for cigarettes than only a front text warning label. We also find that pictorial labels were most effective at encouraging younger smokers to reduce their demand for cigarettes, and plain packaging was most effective at reducing demand among less educated smokers.
Overexpression of a BAHD Acyltransferase, OsAt10, Alters Rice Cell Wall Hydroxycinnamic Acid Content and Saccharification
Authors: Bartley Laura E. , Peck Matthew L. , Kim Sung-Ryul , Ebert Berit , Manisseri Chithra , Chiniquy Dawn M. , Sykes Robert , Gao Lingfang , Rautengarten Carsten , Vega-Sánchez Miguel E. , Benke Peter I. , Canlas Patrick E. , Cao Peijian , Brewer Susan , Lin Fan , Smith Whitney L. , Zhang Xiaohan , Keasling Jay D. , Jentoff Rolf E. , Foster Steven B. , Zhou Jizhong , Ziebell Angela , An Gynheung , Scheller Henrik V. , Ronald Pamela C. 
Published: February 2013

Abstract
Grass cell wall properties influence food, feed, and biofuel feedstock usage efficiency. The glucuronoarabinoxylan of grass cell walls is esterified with the phenylpropanoid-derived hydroxycinnamic acids ferulic acid (FA) and para-coumaric acid (p-CA). Feruloyl esters undergo oxidative coupling with neighboring phenylpropanoids on glucuronoarabinoxylan and lignin. Examination of rice (Oryza sativa) mutants in a grass-expanded and -diverged clade of BAHD acyl-coenzyme A-utilizing transferases identified four mutants with altered cell wall FA or p-CA contents. Here, we report on the effects of overexpressing one of these genes, OsAt10 (LOC_Os06g39390), in rice. An activation-tagged line, OsAT10-D1, shows a 60% reduction in matrix polysaccharide-bound FA and an approximately 300% increase in p-CA in young leaf tissue but no discernible phenotypic alterations in vegetative development, lignin content, or lignin composition. Two additional independent OsAt10 overexpression lines show similar changes in FA and p-CA content. Cell wall fractionation and liquid chromatography-mass spectrometry experiments isolate the cell wall alterations in the mutant to ester conjugates of a five-carbon sugar with p-CA and FA. These results suggest that OsAT10 is a p-coumaroyl coenzyme A transferase involved in glucuronoarabinoxylan modification. Biomass from OsAT10-D1 exhibits a 20% to 40% increase in saccharification yield depending on the assay. Thus, OsAt10 is an attractive target for improving grass cell wall quality for fuel and animal feed.
Conditional Involvement of CONSTITUTIVE PHOTOMORPHOGENIC1 in the Degradation of Phytochrome A
Authors: Debrieux Dimitry , Trevisan Martine , Fankhauser Christian 
Published: February 2013

Abstract
All higher plants possess multiple phytochrome photoreceptors, with phytochrome A (phyA) being light labile and other members of the family being relatively light stable (phyB–phyE in Arabidopsis [Arabidopsis thaliana]). phyA also differs from other members of the family because it enables plants to deetiolate in far-red light-rich environments typical of dense vegetational cover. Later in development, phyA counteracts the shade avoidance syndrome. Light-induced degradation of phyA favors the establishment of a robust shade avoidance syndrome and was proposed to be important for phyA-mediated deetiolation in far-red light. phyA is ubiquitylated and targeted for proteasome-mediated degradation in response to light. Cullin1 and the ubiquitin E3 ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) have been implicated in this process. Here, we systematically analyze the requirement of cullins in this process and show that only CULLIN1 plays an important role in light-induced phyA degradation. In addition, the role of COP1 in this process is conditional and depends on the presence of metabolizable sugar in the growth medium. COP1 acts with SUPPRESSOR OF PHYTOCHROME A (SPA) proteins. Unexpectedly, the light-induced decline of phyA levels is reduced in spa mutants irrespective of the growth medium, suggesting a COP1-independent role for SPA proteins.
Cobalt(II) and cadmium(II) square grids supported with 4,4′-bipyrazole and accommodating 3-carboxyadamantane-1-carboxylate
Authors: Nazarenko Olga M. , Rusanov Eduard B. , Chernega Alexander N. , Domasevitch Konstantin V. 
Published: February 2013

In poly[[bis(μ-4,4′-bi-1H-pyrazole-κ2N2:N2′)bis(3-carboxyadamantane-1-carboxylato-κO1)cobalt(II)] dihydrate], {[Co(C12H15O4)2(C6H6N4)2]·2H2O}n, (I), the Co2+cation lies on an inversion centre and the 4,4′-bipyrazole (4,4′-bpz) ligands are also situated across centres of inversion. In its non-isomorphous cadmium analogue, {[Cd(C12H15O4)2(C6H6N4)2]·2H2O}n, (II), the Cd2+cation lies on a twofold axis. In both compounds, the metal cations adopt an octahedral coordination, with four pyrazole N atoms in the equatorial plane [Co—N = 2.156 (2) and 2.162 (2) Å; Cd—N = 2.298 (2) and 2.321 (2) Å] and two axial carboxylate O atoms [Co—O = 2.1547 (18) Å and Cd—O = 2.347 (2) Å]. In both structures, interligand hydrogen bonding [N...O = 2.682 (3)–2.819 (3) Å] is essential for stabilization of theMN4O2environment with its unusually high (for bulky adamantanecarboxylates) number of coordinatedN-donor co-ligands. The compounds adopt two-dimensional coordination connectivities and exist as square-grid [M(4,4′-bpz)2]nnetworks accommodating monodentate carboxylate ligands. The interlayer linkage is provided by hydrogen bonds from the carboxylic acid groupsviathe solvent water molecules [O...O = 2.565 (3) and 2.616 (3) Å] to the carboxylate groups in the next layer [O...O = 2.717 (3)–2.841 (3) Å], thereby extending the structures in the third dimension.
Invader impact clarifies the roles of top‐down and bottom‐up effects on tropical snake populations
Authors: Brown Gregory P. , Ujvari Beata , Madsen Thomas , Shine Richard 
Published: February 2013

Summary

Disentangling the effects of prey limitation (bottom‐up) and predation (top‐down) processes on natural populations is difficult, but the perturbations introduced by an invasive species can provide pseudo‐experimental evidence on this issue.

In tropical Australia, keelbacks (Tropidonophis mairii) and slatey‐grey snakes (Stegonotus cucullatus) experience little direct cost or benefit from the arrival of toxic invasive cane toads (Rhinella marina), because they rarely eat toads and if they do, are relatively resistant to the toads' toxins. Nonetheless, these snakes could be affected indirectly by toad‐induced decreases in the availability of prey (native frogs) and/or by fatal poisoning of the snakes' predators (large varanid lizards). The former (bottom‐up) effect predicts decreases in snake body condition, feeding and growth rates after toads arrive, whereas the latter (top‐down) effect predicts increases in survival.

Our mark–recapture studies on these snakes in tropical Australia (for 7 years before and 7 years after toad arrival) reveal bottom‐up effects both on an anurophagous dietary specialist (keelbacks) and a generalist feeder (slatey‐grey snakes).

Top‐down effects of toad arrival were seen in keelbacks but not in slatey‐grey snakes, perhaps reflecting the latter's larger body size.

Indirect effects coinciding with the timing of toad invasion thus were mediated through changes in food supply for both native species and in rates of predation for one species.
Spatio‐temporal dynamics of pneumonia in bighorn sheep
Authors: Cassirer E. Frances , Plowright Raina K. , Manlove Kezia R. , Cross Paul C. , Dobson Andrew P. , Potter Kathleen A. , Hudson Peter J. 
Published: February 2013

Summary

Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia‐caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes.

We observed four age‐structured classes of annual pneumonia mortality patterns: all‐age, lamb‐only, secondary all‐age and adult‐only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia‐induced mortality occurring simultaneously across age classes (i.e. all‐age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all‐age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia‐induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality.

Acute pneumonia‐induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups.

We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape‐scale extrinsic variables as drivers of disease.

We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade‐out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management.
Impact of climate change on communities: revealing species' contribution
Authors: Davey Catherine M. , Devictor Vincent , Jonzén Niclas , Lindström Åke , Smith Henrik G. 
Published: February 2013

Summary

Although climate is known to play an important role in structuring biological communities, high‐resolution analyses of recent climatic impacts on multiple components of diversity are still sparse. Additionally, there is a lack of knowledge about which species drive community response to environmental change.

We used a long‐term breeding bird data set that encompasses a large latitudinal and altitudinal range to model the effect of temperature on spatial and temporal patterns in alpha and beta diversity. We also established a novel framework for identifying species‐specific contributions to these macroecological patterns, hence combining two different approaches for identifying climatic impacts.

Alpha diversity increased over time, whilst beta diversity declined; both diversity metrics showed a significant relationship with recent temperature anomalies. By partitioning beta diversity, we showed that the decline was predominately driven by changes in species turnover rather than nestedness suggesting a process of replacement by more common species.

Using jackknife analyses we identified how individual species influenced the modelled relationships of diversity with temperature and time. Influential species tended to be habitat generalists with moderate to large distributions.

We demonstrate that different facets of avian diversity can respond rapidly to temperature anomalies and as a result have undergone significant changes in the last decade. In general, it appears that warming temperatures are driving compositional homogenization of temperate bird communities via range expansion of common generalist species.
Chinese Loess Plateau vegetation since the Last Glacial Maximum and its implications for vegetation restoration
Authors: Jiang Wenying , Cheng Yufen , Yang Xiaoxiao , Yang Shiling 
Published: February 2013

Summary

China has been investing heavily in afforestation programmes to control soil erosion on the vast Chinese Loess Plateau (CLP). This massive afforestation has led to a considerable increase in forest and a decrease in dust‐storm activity in some areas. However, there have also been some negative outcomes, including low tree survival rate, increased soil erosion, exacerbated water shortages and deep soil desiccation. One important explanation for these is the use of inappropriate species because of a lack of knowledge of the natural vegetation in the area, which has been largely destroyed by human activities.

Natural vegetation in the most recent warm period (the early–mid‐Holocene) can serve as an analogue for the ongoing greening programme, particularly under the global warming scenario. In this study, the natural vegetation of the CLP since the Last Glacial Maximum (LGM) was reconstructed from pollen analyses of six loess sections.

Our results show that herbs were dominant both in the cold–dry LGM and the warm–humid early–mid‐Holocene. During the LGM, vegetation in the north‐western CLP mainly consisted of Artemisia, Echinops‐type, Taraxacum‐type and Chenopodiaceae, and vegetation in the south‐eastern CLP was characterized by the same types but with a slightly higher incidence of Poaceae. During the early–mid‐Holocene, vegetation was more diverse, with Poaceae, Artemisia, Echinops‐type and Chenopodiaceae dominant in the north‐west, and Pinus, Corylus, Poaceae, Artemisia and Selaginella sinensis dominant in the south‐east.

Synthesis and applications. The ecological restoration of herbs should be considered a priority, although trees and shrubs have been prioritized previously. To balance environmental conservation and farm‐income support objectives, we suggest planting Corylus, Juglans and Selaginella sinensis in the south‐eastern Chinese Loess Plateau (CLP) because of their edible value or medicinal properties. Given the considerable prevalence of Selaginella sinensis and the Asteraceae family in the pollen records, and their useful medicinal effects, the CLP has great potential to be a centre for Chinese medicinal herb production.