bluuebunny/crossref_metadata_2025_split huggingface dataset:
The morphology and ultrastructure of the nectaries of marrow (Cucurbita pepo L. convar. giromontiina)
Authors: Dmitruk Marta , Weryszko-Chmielewska Elżbieta 
Published: October 2013

The present study investigated the size and structure of the nectaries in flowers of marrow – <em>Cucurbita pepo </em>convar.<em> giromontiina </em>cv. ‘Weiser Busch’. The diameter and thickness of nectariferous layer were compared in female and male flowers of this taxon. The micromorphology as well as the anatomical and ultrastructural characters of the nectary from the female flower were observed using light, scanning and transmission electron microscopy. The density and size of stomata of the nectary epidermis from both types of flowers were examined using light microscopy. The nectaries in female flowers were found to have a larger size than in male flowers. The stomata occurring in the nectary epidermis of both types of flowers have a similar size and density. We observed that nectar was released onto the surface of the nectary not only via the stomata, but also through the walls of the epidermal cells. In TEM examination, large nuclei, different-shaped plastids, ER tubules, dictyosomes, and ribosomes were observed in the nectariferous tissue cells. A large number of mitochondria accompanying the plastids were found in the parenchyma cells of the nectary. The degradation of the nectary parenchyma cells in the flowers living for about 6 hours was asynchronous.
Weed species diversity in organic and integrated farming systems
Authors: Jastrzębska Magdalena , Jastrzębski Wiesław P. , Hołdyński Czesław , Kostrzewska Marta K. 
Published: October 2013

Phytosociological data were collected in 1994–1996 in plots (relevés) at the Research Station for Organic Farming and Conservation Breeding of the Polish Academy of Sciences in Popielno included in a large-area experiment conducted according to the concept and method proposed by Prof. S. Nawrocki. In a four-field crop rotation (root crops – spring barley undersown with red clover and grasses – red clover/grass mixture – winter triticale), each field was divided into two management units, organic and integrated. Data were collected in relevés by the Braun-Blanquet method, each year at the peak of the growing season. Weed abundance (% cover) in cultivated fields and the number of weed species (species richness) in crops were determined, which provided a basis for calculating the Shannon-Wiener indices of species diversity and evenness, and the Rényi profiles. The qualitative (species) and quantitative structure of weed communities was compared using the Sørensen index. A total of 115 weed taxa (species, subspecies and varieties) were identified in the examined agro-phytocenoses. <em>Echinochloa crus-galli</em>, <em>Chenopodium album</em>, <em>Matricaria maritima</em> subsp. <em>inodora</em>, <em>Capsella bursa-pastoris</em>, <em>Thlaspi arvense</em> and <em>Stellaria media</em> were the most abundant<em>.</em> Weed infestation was slightly higher in the organic farming system than in the integrated system. Organic farming contributed to higher weed species diversity in root crops, red clover/grass mixtures and winter triticale. Weed species richness was reduced in red clover/grass stands, while root crops and – to a lesser degree – spring barley undersown with red clover and grasses decreased weed species diversity. The species composition and in particular the quantitative structure of weeds were affected by crop species and cultivation regime rather than by the farming system. Weed communities of crops grown under organic and integrated farming systems were more similar with regard to species composition than the quantitative structure.
Le rapport à la culture des enseignants : proposition d’un cadre théorique
Authors: Falardeau Érick , Simard Denis 
Published: October 2013

Cet article vise à présenter les résultats d’une recherche exploratoire sur la relation entre le rapport à la culture d’étudiants en enseignement et la mise en œuvre d’une approche culturelle dans la discipline « français », ainsi qu’à préciser un cadre théorique du rapport à la culture. Nous avons analysé les textes de 35 étudiants, dans lesquels ils devaient définir ce que signifie pour eux la culture et leur conception du rôle de l’enseignant dans le développement culturel des élèves. Une analyse de contenu nous a permis de circonscrire quatre types de rapport à la culture : désimpliqué, instrumentaliste, scolaire et intégratif-évolutif, ainsi que deux plans, individuel et pédagogique — soit l’accompagnement de l’élève dans son développement culturel.
Cloud Computing with iPlant Atmosphere
Authors: McKay Sheldon J. , Skidmore Edwin J. , LaRose Christopher J. , Mercer Andre W. , Noutsos Christos 
Published: October 2013

AbstractCloud Computing refers to distributed computing platforms that use virtualization software to provide easy access to physical computing infrastructure and data storage, typically administered through a Web interface. Cloud‐based computing provides access to powerful servers, with specific software and virtual hardware configurations, while eliminating the initial capital cost of expensive computers and reducing the ongoing operating costs of system administration, maintenance contracts, power consumption, and cooling. This eliminates a significant barrier to entry into bioinformatics and high‐performance computing for many researchers. This is especially true of free or modestly priced cloud computing services. The iPlant Collaborative offers a free cloud computing service, Atmosphere, which allows users to easily create and use instances on virtual servers preconfigured for their analytical needs. Atmosphere is a self‐service, on‐demand platform for scientific computing. This unit demonstrates how to set up, access and use cloud computing in Atmosphere. Curr. Protoc. Bioinform. 43:9.15.1‐9.15.20. © 2013 by John Wiley & Sons, Inc.
LipidXplorer: Software for Quantitative Shotgun Lipidomics Compatible with Multiple Mass Spectrometry Platforms
Authors: Herzog Ronny , Schwudke Dominik , Shevchenko Andrej 
Published: October 2013

AbstractLipidXplorer is an open‐source software kit that supports the identification and quantification of molecular species of any lipid class detected by shotgun experiments performed on any mass spectrometry platform. LipidXplorer does not rely on a database of reference spectra: instead, lipid identification routines are user defined in the declarative molecular fragmentation query language (MFQL). The software supports batch processing of multiple shotgun acquisitions by high‐resolution mass mapping, precursor and neutral‐loss scanning, and data‐dependent MS/MS lending itself to a variety of lipidomics applications in cell biology and molecular medicine. Curr. Protoc. Bioinform. 43:14.12.1‐14.12.30. © 2013 by John Wiley & Sons, Inc.
The 2008 Emiliania huxleyi bloom along the Patagonian Shelf: Ecology, biogeochemistry, and cellular calcification
Authors: Poulton Alex J. , Painter Stuart C. , Young Jeremy R. , Bates Nicholas R. , Bowler Bruce , Drapeau Dave , Lyczsckowski Emily , Balch William M. 
Published: October 2013

AbstractCoccolithophore blooms are significant contributors to the global production and export of calcium carbonate (calcite). The Patagonian Shelf is a site of intense annual coccolithophore blooms during austral summer. During December 2008, we made intensive measurements of the ecology, biogeochemistry, and physiology of a coccolithophore bloom. High numbers of Emiliania huxleyi cells and detached coccoliths (>1 × 103 mL−1 and >10 × 103 mL−1, respectively), high particulate inorganic carbon concentrations (>10 mmol C m−2), and high calcite production (up to 7.3 mmol C m−2 d−1) all characterized bloom waters. The bloom was dominated by the low‐calcite‐containing B/C morphotype of Emiliania huxleyi, although a small (<10 µm) Southern Ocean diatom of the genus Fragilariopsis was present in almost equal numbers (0.2–2 × 103 mL−1). Estimates of Fragilariopsis contributions to chlorophyll, phytoplankton carbon, and primary production were >30%, similar to estimates for E. huxleyi and indicative of a significant role for this diatom in bloom biogeochemistry. Cell‐normalized calcification rates, when corrected for a high number of nonactive cells, were relatively high and when normalized to estimates of coccolith calcite indicate excessive coccolith production in the declining phase of the bloom. We find that low measures of calcite and calcite production relative to other blooms in the global ocean indicate that the dominance of the B/C morphotype may lead to overall lower calcite production. Globally, this suggests that morphotype composition influences regional bloom inventories of carbonate production and export and that climate‐induced changes in morphotype biogeography could affect the carbon cycle.
Adjoint estimation of ozone climate penalties
Authors: Zhao Shunliu , Pappin Amanda J. , Morteza Mesbah S. , Joyce Zhang J. Y. , MacDonald Nicole L. , Hakami Amir 
Published: October 2013

AbstractAn adjoint of a regional chemical transport model is used to calculate location‐specific temperature influences (climate penalties) on two policy‐relevant ozone metrics: concentrations in polluted regions (>65 ppb) and short‐term mortality in Canada and the U.S. Temperature influences through changes in chemical reaction rates, atmospheric moisture content, and biogenic emissions exhibit significant spatial variability. In particular, high‐NOx, polluted regions are prominently distinguished by substantial climate penalties (up to 6.2 ppb/K in major urban areas) as a result of large temperature influences through increased biogenic emissions and nonnegative water vapor sensitivities. Temperature influences on ozone mortality, when integrated across the domain, result in 369 excess deaths/K in Canada and the U.S. over a summer season—an impact comparable to a 5% change in anthropogenic NOx emissions. As such, we suggest that NOx control can be also regarded as a climate change adaptation strategy with regard to ozone air quality.
Surface freshwater storage and variability in the Amazon basin from multi‐satellite observations, 1993–2007
Authors: Papa Fabrice , Frappart Frederic , Güntner Andreas , Prigent Catherine , Aires Filipe , Getirana Augusto C. V. , Maurer Raffael 
Published: October 2013

AbstractThe amount of water stored and moving through the surface water bodies of large river basins (river, floodplains, wetlands) plays a major role in the global water and biochemical cycles and is a critical parameter for water resources management. However, the spatiotemporal variations of these freshwater reservoirs are still widely unknown at the global scale. Here, we propose a hypsographic curve approach to estimate surface freshwater storage variations over the Amazon basin combining surface water extent from a multi‐satellite‐technique with topographic data from the Global Digital Elevation Model (GDEM) from Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Monthly surface water storage variations for 1993–2007 are presented, showing a strong seasonal and interannual variability, and are evaluated against in situ river discharge and precipitation. The basin‐scale mean annual amplitude of ~1200 km3 is in the range of previous estimates and contributes to about half of the Gravity Recovery And Climate Experiment (GRACE) total water storage variations. For the first time, we map the surface water volume anomaly during the extreme droughts of 1997 (October–November) and 2005 (September–October) and found that during these dry events the water stored in the river and floodplains of the Amazon basin was, respectively, ~230 (~40%) and 210 (~50%) km3 below the 1993–2007 average. This new 15 year data set of surface water volume represents an unprecedented source of information for future hydrological or climate modeling of the Amazon. It is also a first step toward the development of such database at the global scale.
Trends in aerosol optical depth over Indian region: Potential causes and impact indicators
Authors: Babu S. Suresh , Manoj M. R. , Moorthy K. Krishna , Gogoi Mukunda M. , Nair Vijayakumar S. , Kompalli Sobhan Kumar , Satheesh S. K. , Niranjan K. , Ramagopal K. , Bhuyan P. K. , Singh Darshan 
Published: October 2013

AbstractThe first regional synthesis of long‐term (back to ~ 25 years at some stations) primary data (from direct measurement) on aerosol optical depth from the ARFINET (network of aerosol observatories established under the Aerosol Radiative Forcing over India (ARFI) project of Indian Space Research Organization over Indian subcontinent) have revealed a statistically significant increasing trend with a significant seasonal variability. Examining the current values of turbidity coefficients with those reported ~ 50 years ago reveals the phenomenal nature of the increase in aerosol loading. Seasonally, the rate of increase is consistently high during the dry months (December to March) over the entire region whereas the trends are rather inconsistent and weak during the premonsoon (April to May) and summer monsoon period (June to September). The trends in the spectral variation of aerosol optical depth (AOD) reveal the significance of anthropogenic activities on the increasing trend in AOD. Examining these with climate variables such as seasonal and regional rainfall, it is seen that the dry season depicts a decreasing trend in the total number of rainy days over the Indian region. The insignificant trend in AOD observed over the Indo‐Gangetic Plain, a regional hot spot of aerosols, during the premonsoon and summer monsoon season is mainly attributed to the competing effects of dust transport and wet removal of aerosols by the monsoon rain. Contributions of different aerosol chemical species to the total dust, simulated using Goddard Chemistry Aerosol Radiation and Transport model over the ARFINET stations, showed an increasing trend for all the anthropogenic components and a decreasing trend for dust, consistent with the inference deduced from trend in Angstrom exponent.
The transition from circular to elliptical impact craters
Authors: Elbeshausen Dirk , Wünnemann Kai , Collins Gareth S. 
Published: October 2013

AbstractElliptical impact craters are rare among the generally symmetric shape of impact structures on planetary surfaces. Nevertheless, a better understanding of the formation of these craters may significantly contribute to our overall understanding of hypervelocity impact cratering. The existence of elliptical craters raises a number of questions: Why do some impacts result in a circular crater whereas others form elliptical shapes? What conditions promote the formation of elliptical craters? How does the formation of elliptical craters differ from those of circular craters? Is the formation process comparable to those of elliptical craters formed at subsonic speeds? How does crater formation work at the transition from circular to elliptical craters? By conducting more than 800 three‐dimensional (3‐D) hydrocode simulations, we have investigated these questions in a quantitative manner. We show that the threshold angle for elliptical crater generation depends on cratering efficiency. We have analyzed and quantified the influence of projectile size and material strength (cohesion and coefficient of internal friction) independently from each other. We show that elliptical craters are formed by shock‐induced excavation, the same process that forms circular craters and reveal that the transition from circular to elliptical craters is characterized by the dominance of two processes: A directed and momentum‐controlled energy transfer in the beginning and a subsequent symmetric, nearly instantaneous energy release.
Using a Kinase‐Inducible Bimolecular Switch to Control Enzyme Activity in Living Cells
Authors: Mehta Sohum , Zhang Jin 
Published: October 2013

AbstractMolecular switches have been instrumental in the development of powerful and versatile genetic tools for directly probing biochemical processes, such as intracellular signaling, within their native contexts. A molecular switch can be broadly defined as a molecular system capable of existing in either of two states (e.g., conformations), which can be converted from one state to the other by a specific input stimulus. This protocol outlines a method for using a kinase‐inducible bimolecular switch, along with live‐cell fluorescence microscopy, to directly control and monitor the activity of a specific enzyme in living cells. Curr. Protoc. Chem. Biol. 5:227‐237 © 2013 by John Wiley & Sons, Inc.
Vertical Price Transmission of Milk Prices: Are Small Dairy Producers Efficiently Integrated Into Markets?
Authors: Acosta Alejandro , Valdés Alberto 
Published: October 2013

ABSTRACTIn recent years the dairy sector in Panama has experienced mergers and consolidations that have led to increases in industry concentration, a decrease in the number of producers, and an increase in the scale of operations. Small dairy producers have expressed concerns about the competitiveness of the dairy supply chain, arguing that price changes are not being transmitted efficiently from wholesalers to producer at the farm gate level. In this context, this study examines the degree of vertical price transmission between wholesalers and small dairy producers to assess the efficiency level of the dairy market chain in Panama. The findings of this research provide original and important contributions to the policy dialogue uncovering two key issues: 1) a unidirectional transmission of milk prices from producers to wholesaler, and 2) that the transmission of milk prices is asymmetric depending on whether prices are increasing or decreasing. [EconLit Classifications: Q11, Q13, Q18].
A test of three hypotheses of pica and amylophagy among pregnant women in Tamil Nadu, India
Authors: Placek Caitlyn D. , Hagen Edward H. 
Published: October 2013

ObjectivesPica has been studied in India and elsewhere for more than 100 years, yet no compelling and empirically well‐supported explanation for it has emerged. Amylophagy, sometimes considered a type of pica and sometimes studied separately, is less frequently investigated and also lacks a convincing explanation. This study used a biocultural approach to test three hypotheses of pica and amylophagy: protection, hunger/nutrition, and psychological distress.MethodsThe research took place in Tamil Nadu, India. In study 1, a cultural investigation was carried out among nonpregnant, adult women (n = 54) to determine nonfood substances that are consumed in this region and perceptions of health consequences. Next, using the substances identified in Study 1, three hypotheses of pica and amylophagy were tested in a cross‐sectional study of pregnant women (Study 2,n = 95). Logistic regression analysis was used to analyze the presence or absence of engaging in pica and amylophagy. A series of bivariate analyses were used to examine the variation in amount and frequency of consumption.ResultsStudy 1 revealed that cultural attitudes strongly shape the selection of nonfood substances. In Study 2, the presence or absence of pica was not predicted by any of the variables included in the study, whereas the frequency and amount of consumption of pica substances were primarily explained by the psychological distress and hunger/nutrition hypotheses. Both the presence or absence of amylophagy as well as the frequency and amount of consumption were best explained by the protection hypothesis.ConclusionsThis research provided partial support for the protection and hunger/nutrition hypotheses for amylophagy, and also provided some evidence for the role of psychological distress and hunger or nutrition in pica. Am. J. Hum. Biol. 25:803–813, 2013. © 2013 Wiley Periodicals, Inc.
Polymorphism of LRP5, but not of TNFRSF11B, is associated with a decrease in bone mineral density in postmenopausal maya‐mestizo women
Authors: Canto‐Cetina Thelma , Polanco Reyes Lucila , González Herrera Lizbeth , Rojano‐Mejía David , Coral‐Vázquez Ramón Mauricio , Coronel Agustín , Canto Patricia 
Published: October 2013

ABSTRACTObjectiveOsteoporosis is a complex disease characterized principally by low bone mineral density (BMD), which is determined by an interaction of genetic, metabolic, and environmental factors. The aim of this study was to analyze the possible association among one polymorphism of LRP5 and three polymorphisms of TNFRSF11B as well as their haplotypes with BMD variations in Maya‐Mestizo postmenopausal women.MethodsWe studied 583 postmenopausal women of Maya‐Mestizo ethnic origin. A structured questionnaire for risk factors was applied and BMD was measured in lumbar spine (LS), total hip (TH), and femoral neck (FN) by dual‐energy X‐ray absorptiometry. DNA was obtained from blood leukocytes. One single‐nucleotide polymorphism of LRP5 (rs3736228, p.A1330V) and three of TNFRSF11B (rs4355801, rs2073618, and rs6993813) were studied using real‐time PCR allelic discrimination for genotyping. Differences between the means of the BMDs according to the genotype were analyzed with covariance. Deviations from Hardy–Weinberg equilibrium were tested. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r2, and haplotype analysis of TNFRSF11B was conducted.ResultsThe Val genotype of the rs3736228 (p.A1330V) of LRP5 was significantly associated with BMD variations at the LS, TH, and FN. None of the three polymorphisms of TNFRSF11B was associated with BMD variations.ConclusionsOur results show that p.A1330V was significantly associated with BMD variations at all three skeletal sites analyzed; the Val allele and the Val/Val genotype were those most frequently found in our population. Am. J. Hum. Biol. 25:713–718, 2013. © 2013 Wiley Periodicals, Inc.
Ovarian function in Samoan women shows stronger association with signals of energy metabolism than fat reserves
Authors: Sherry Diana S. , Mcgarvey Stephen T. , Sesepasara Margaret L. , Ellison Peter T. 
Published: October 2013

ObjectivesThe relative influence of prominent energetic hormones such as insulin and leptin on ovarian steroid production has yet to be determined and demonstrated consistently in vivo. This study reports preliminary findings on the relationship between insulin, leptin, and estradiol, a major ovarian steroid, in a sample of Samoan women.MethodsParticipants were 34 regularly cycling, nonlactating, premenopausal women in the follicular phase of their menstrual cycle with indicators of normal glucose tolerance. Fasting serum samples provided one‐time, cross‐sectional measures of glucose, insulin, leptin, and estradiol. Main statistical analyses consisted of Student's t‐tests, used to determine significant differences in mean estradiol level between contrasting groups of insulin and leptin.ResultsRelatively high insulin levels within the normal range of variation showed a positive association with estradiol levels whereas relatively high leptin levels did not. The association between insulin and estradiol appeared to conform to a step‐like categorical relationship—with the highest insulin levels exerting the greatest positive effect—rather than a dose‐response linear relationship.ConclusionsThis study adds to the growing evidence that peripheral regulation of ovarian function likely involves permissive signals that emphasize a state of energy surplus, related primarily to energy metabolism rather than energy reserves, and warrant more extensive study. Am. J. Hum. Biol. 26:95–98, 2014. © 2013 Wiley Periodicals, Inc.