bluuebunny/crossref_metadata_2025 huggingface dataset:
Water consumption from hydropower plants – review of published estimates and an assessment of the concept
Authors: Bakken T. H. , Killingtveit Å. , Engeland K. , Alfredsen K. , Harby A.
Published: October 2013

Abstract. Since the report from IPCC on renewable energy (IPCC, 2012) was published; more studies on water consumption from hydropower have become available. The newly published studies do not, however, contribute to a more consistent picture on what the "true" water consumption from hydropower plants is. The dominant calculation method is the gross evaporation from the reservoirs divided by the annual power production, which appears to be an over-simplistic calculation method that possibly produces a biased picture of the water consumption of hydropower plants. This review paper shows that the water footprint of hydropower is used synonymously with water consumption, based on gross evaporation rates. This paper also documents and discusses several methodological problems when applying this simplified approach (gross evaporation divided by annual power production) for the estimation of water consumption from hydropower projects. A number of short-comings are identified, including the lack of clarity regarding the setting of proper system boundaries in space and time. The methodology of attributing the water losses to the various uses in multi-purpose reservoirs is not developed. Furthermore, a correct and fair methodology for handling water consumption in reservoirs based on natural lakes is needed, as it appears meaningless that all the evaporation losses from a close-to-natural lake should be attributed to the hydropower production. It also appears problematic that the concept is not related to the impact the water consumption will have on the local water resources, as high water consumption values might not be problematic per se. Finally, it appears to be a paradox that a reservoir might be accorded a very high water consumption/footprint and still be the most feasible measure to improve the availability of water in a region. We argue that reservoirs are not always the problem; rather they may contribute to the solution of the problems of water scarcity. The authors consider that an improved conceptual framework is needed in order to calculate the water footprint from hydropower projects in a more reasonable way.
Attribution of detected changes in streamflow using multiple working hypotheses
Authors: Harrigan S. , Murphy C. , Hall J. , Wilby R. L. , Sweeney J.
Published: October 2013

Abstract. This paper revisits a widely cited study of the Boyne catchment in the east of Ireland that attributed a change in streamflow during the mid-1970s to increased precipitation linked to a shift in the North Atlantic Oscillation. Using the method of Multiple Working Hypotheses we explore a wider set of potential drivers of hydrological change. Rainfall-runoff models are employed to reconstruct streamflow to isolate the effect of climate taking account of both model structure and parameter uncertainty. The Mann–Kendall test for monotonic trend and Pettitt change point test are applied to explore signatures of change. Different to earlier work, arterial drainage and the simultaneous onset of field drainage in the 1970s and early 1980s were inferred to be the predominant driver of change within the Boyne. There is evidence that a change in precipitation regime is also present, albeit to a lesser extent. This new explanation posits that multiple drivers acting simultaneously were responsible for the observed change. This work highlights the utility of the Multiple Working Hypotheses framework in moving towards more rigorous attribution, which is an important part of managing unfolding impacts on hydrological systems.
Forecasting terrestrial water storage changes in the Amazon Basin using Atlantic and Pacific sea surface temperatures
Authors: de Linage C. , Famiglietti J. S. , Randerson J. T.
Published: October 2013

Abstract. Floods and droughts frequently affect the Amazon River basin, impacting transportation, river navigation, agriculture, and ecosystem processes within several South American countries. Here we examined how sea surface temperatures (SSTs) influence interannual variability of terrestrial water storage anomalies (TWSAs) in different regions within the Amazon basin and propose a modeling framework for inter-seasonal flood and drought forecasting. Three simple statistical models forced by a linear combination of lagged spatial averages of central Pacific (Niño 4 index) and tropical North Atlantic (TNAI index) SSTs were calibrated against a decade-long record of 3°, monthly TWSAs observed by the Gravity Recovery And Climate Experiment (GRACE) satellite mission. Niño 4 was the primary external forcing in the northeastern region of the Amazon basin whereas TNAI was dominant in central and western regions. A combined model using the two indices improved the fit significantly (p < 0.05) for at least 64% of the grid cells within the basin, compared to models forced solely with Niño 4 or TNAI. The combined model explained 66% of the observed variance in the northeastern region, 39% in the central and western regions, and 43% for the Amazon basin as a whole with a 3 month lead time between the SST indices and TWSAs. Model performance varied seasonally: it was higher than average during the rainfall wet season in the northeastern Amazon and during the dry season in the central and western regions. The predictive capability of the combined model was degraded with increasing lead times. Degradation was smaller in the northeastern Amazon (where 49% of the variance was explained using an 8 month lead time vs. 69% for a 1 month lead time) compared to the central and western Amazon (where 22% of the variance was explained at 8 months vs. 43% at 1 month). These relationships may enable the development of an early warning system for flood and drought risk. This work also strengthens our understanding of the mechanisms regulating interannual variability in Amazon fires, as water storage deficits may subsequently lead to decreases in transpiration and atmospheric water vapor that cause more severe fire weather.
When does higher spatial resolution rainfall information improve streamflow simulation? An evaluation on 3620 flood events
Authors: Lobligeois F. , Andréassian V. , Perrin C. , Tabary P. , Loumagne C.
Published: October 2013

Abstract. Precipitation is the key factor controlling the high-frequency hydrological response in catchments, and streamflow simulation is thus dependent on the way rainfall is represented in the hydrological model. A characteristic that distinguishes distributed from lumped models is the ability to explicitly represent the spatial variability of precipitation. Although the literature on this topic is abundant, the results are contrasted and sometimes contradictory. This paper investigates the impact of spatial rainfall on runoff generation to better understand the conditions where higher-resolution rainfall information improves streamflow simulations. In this study, we used the rainfall reanalysis developed by Météo-France over the whole French territory at 1 km and 1 h resolution over a 10 yr period. A hydrological model was applied in the lumped mode (a single spatial unit) and in the semi-distributed mode using three unit sizes of sub-catchments. The model was evaluated against observed streamflow data using split-sample tests on a large set of 181 French catchments representing a variety of size and climate conditions. The results were analyzed by catchment classes and types of rainfall events based on the spatial variability of precipitation. The evaluation clearly showed different behaviors. The lumped model performed as well as the semi-distributed model in western France where catchments are under oceanic climate conditions with quite spatially uniform precipitation fields. In contrast, higher resolution in precipitation inputs significantly improved the simulated streamflow dynamics and accuracy in southern France (Cévennes and Mediterranean regions) for catchments in which precipitation fields were identified to be highly variable in space. In all regions, natural variability allows for contradictory examples to be found, showing that analyzing a large number of events over varied catchments is warranted.
A workflow for building and calibrating 3-D geomechanical models &ndash a case study for a gas reservoir in the North German Basin
Authors: Fischer K. , Henk A.
Published: October 2013

Abstract. The optimal use of conventional and unconventional hydrocarbon reservoirs depends, amongst other things, on the local tectonic stress field. For example, wellbore stability, orientation of hydraulically induced fractures and – especially in fractured reservoirs – permeability anisotropies are controlled by the present-day in situ stresses. Faults and lithological changes can lead to stress perturbations and produce local stresses that can significantly deviate from the regional stress field. Geomechanical reservoir models aim for a robust, ideally "pre-drilling" prediction of the local variations in stress magnitude and orientation. This requires a numerical modelling approach that is capable to incorporate the specific geometry and mechanical properties of the subsurface reservoir. The workflow presented in this paper can be used to build 3-D geomechanical models based on the finite element (FE) method and ranging from field-scale models to smaller, detailed submodels of individual fault blocks. The approach is successfully applied to an intensively faulted gas reservoir in the North German Basin. The in situ stresses predicted by the geomechanical FE model were calibrated against stress data actually observed, e.g. borehole breakouts and extended leak-off tests. Such a validated model can provide insights into the stress perturbations in the inter-well space and undrilled parts of the reservoir. In addition, the tendency of the existing fault network to slip or dilate in the present-day stress regime can be addressed.
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 – Cucurbita pepo convar. giromontiina 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. Echinochloa crus-galli, Chenopodium album, Matricaria maritima subsp. inodora, Capsella bursa-pastoris, Thlaspi arvense and Stellaria media were the most abundant. 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.
L’enseignement en contexte d’inclusion : proposition d’un modèle d’analyse des pratiques d’adaptation
Authors: Nootens Pascale , Debeurme Godelieve
Published: October 2013

Cet article a pour visée première de contribuer à la réflexion portant sur l’adaptation de l’enseignement en contexte d’inclusion d’élèves en difficulté d’apprentissage au primaire. L’inclusion est aujourd’hui la voie d’éducation privilégiée au Québec (Bélanger, 2006), où l’adaptation de l’enseignement est essentielle à la réussite de ces élèves (Vienneau, 2006). Or, les pratiques d’adaptation de l’enseignement restent peu explorées. L’absence d’assises conceptuelles soutenant l’analyse de ces pratiques semble en partie en cause. Ainsi, le présent article rappelle d’abord la problématique actuelle de l’adaptation de l’enseignement en contexte d’inclusion. Ensuite, prenant appui sur les contributions de certains auteurs à l’élaboration d’éléments conceptuels en la matière (Switlick, 1997; Schumm, 1999; Friend et Bursuck, 1999; Vienneau, 2006), il propose les premiers jalons d’un modèle pouvant soutenir l’analyse de pratiques d’adaptation de l’enseignement.
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.
Engagement organisationnel et citoyenneté organisationnelle d’enseignants
Authors: Roux Stéphane , Dussault Marc
Published: October 2013

Cet article présente les résultats d’une étude visant à analyser la relation entre l’engagement organisationnel et la citoyenneté organisationnelle d’enseignantes et d’enseignants. S’inspirant de la théorie trifactorielle de Meyer et Allen (1991), l’étude prévoit que l’engagement affectif constitue un meilleur prédicteur de la citoyenneté organisationnelle des enseignants que l’engagement normatif et de continuité. L’étude prévoit aussi que la perception de justice peut jouer un rôle modérateur entre l’engagement et la citoyenneté. Des enseignantes et des enseignants (n = 221) provenant d’écoles privées de niveau secondaire du Québec ont participé à l’étude. Les résultats révèlent que l’engagement affectif est davantage corrélé à la citoyenneté organisationnelle que les autres types d’engagement. De plus, la perception de justice semble jouer un rôle modérateur sur la relation entre ces deux variables.
Cloud Computing with iPlant Atmosphere
Authors: McKay Sheldon J. , Skidmore Edwin J. , LaRose Christopher J. , Mercer Andre W. , Noutsos Christos
Published: October 2013

Cloud 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

LipidXplorer 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.
AGU Appoints New Journal Editors
Authors: Hanson Brooks
Published: October 2013

Geochemistry, Geophysics, Geosystems has added Janne Blichert‐Toft (Laboratoire de Geologie de Lyon, Centre National de la Recherche Scientifique) to its editorial board.
High rate of methane leakage from natural gas production
Authors: Balcerak Ernie
Published: October 2013

Natural gas production is growing as the United States seeks domestic sources of relatively clean energy. Natural gas combustion produces less carbon dioxide emissions than coal or oil for the amount of energy produced. However, one source of concern is that some natural gas leaks to the atmosphere from the extraction point, releasing methane, a potent greenhouse gas.
Unusual rainfall in Australia explains global sea level drop in 2011
Authors: Balcerak Ernie
Published: October 2013

Since 1993, global mean sea level has been rising by about 3 millimeters per year on average, with some year‐to‐year variations. However, from mid‐2010 through 2011, the sea level unexpectedly dropped by 7 millimeters relative to this background trend. To investigate the cause of the unusual sea level drop, Fasullo et al. examined data from the Gravity Recovery and Climate Experiment (GRACE) satellite, which can determine water content on land and sea through gravity variations, as well as altimetry data, reanalyses of other previously collected data, global precipitation data, and data on continental river discharge rates.
Nuclear test monitoring system detected meteor explosion over Russia
Authors: Balcerak Ernie
Published: October 2013

Sound waves from the Chelyabinsk meteor, which exploded over Russia on 15 February 2013, were detected by 20 infrasound stations that are part of the international monitoring system operated by the Comprehensive Nuclear‐Test‐Ban Treaty Organization (CTBTO). The fireball was the most energetic event observed since the 1908 Tunguska meteorite impact and is the most energetic event detected by the CTBTO network.
Structure and interactions within the pelagic microbial food web (from viruses to microplankton) across environmental gradients in the Mediterranean Sea
Authors: Di Poi E. , Blason C. , Corinaldesi C. , Danovaro R. , Malisana E. , Fonda‐Umani S.
Published: October 2013

We have investigated here the structure of the pelagic microbial food web and quantified the carbon fluxes from viruses to microplankton along trophic gradients in the Mediterranean Sea. To explore the complex trophic pathways of the pelagic food web, we conducted independent and replicated experiments to measure (i) predation on prokaryotes by microzooplankton, (ii) predation on prokaryotes by heterotrophic nanoflagellates, (iii) virus‐induced prokaryotic mortality, and (iv) microzooplankton grazing on nanoplankton and microphytoplankton. Our study covered more than 5000 km, from the Atlantic Ocean to the Levantine basin, and from conditions of high primary production and nutrient availability to ultraoligotrophic and phosphate‐limited waters. Microphytoplankton abundance and biomass were typically scarce across the entire Mediterranean basin, with almost negligible levels in the eastern part. Also, nanoplankton biomass was typically low. Conversely, prokaryotes, and particularly the heterotrophic components, were abundant and represented the only significant food source for both nanoplankton and microplankton grazers. Viral infections were not the primary agents of prokaryotic mortality, but in some areas, such as the Ligurian Sea, they had a key role in prokaryotic dynamics. The scenario depicted in this study in summer reveals the pivotal role of microzooplankton in the pelagic food web of the Mediterranean Sea, with a key role in the potential transfer of biomass to higher trophic levels. We also show that converse to theoretical expectations, the microbial food web was relatively complex under the mesotrophic conditions (Atlantic and western Mediterranean) and was much more simplified in the ultraoligotrophic conditions of the eastern Mediterranean.
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

Coccolithophore 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

An 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.
Large‐scale, realistic laboratory modeling of M2 internal tide generation at the Luzon Strait
Authors: Mercier Matthieu J. , Gostiaux Louis , Helfrich Karl , Sommeria Joel , Viboud Samuel , Didelle Henri , Ghaemsaidi Sasan J. , Dauxois Thierry , Peacock Thomas
Published: October 2013

The complex double‐ridge system in the Luzon Strait in the South China Sea (SCS) is one of the strongest sources of internal tides in the oceans, associated with which are some of the largest amplitude internal solitary waves on record. An issue of debate, however, has been the specific nature of their generation mechanism. To provide insight, we present the results of a large‐scale laboratory experiment performed at the Coriolis platform. The experiment was carefully designed so that the relevant dimensionless parameters, which include the excursion parameter, criticality, Rossby, and Froude numbers, closely matched the ocean scenario. The results advocate that a broad and coherent weakly nonlinear, three‐dimensional, M2 internal tide that is shaped by the overall geometry of the double‐ridge system is radiated into the South China Sea and subsequently steepens, as opposed to being generated by a particular feature or localized region within the ridge system.
Measurements of the mass absorption cross section of atmospheric soot particles using Raman spectroscopy
Authors: Nordmann S. , Birmili W. , Weinhold K. , Müller K. , Spindler G. , Wiedensohler A.
Published: October 2013

Soot particles are a major absorber of shortwave radiation in the atmosphere. The mass absorption cross section is an essential quantity to describe this light absorption process. This work presents new experimental data on the mass absorption cross section of soot particles in the troposphere over Central Europe. Mass absorption cross sections were derived as the ratio between the light absorption coefficient determined by multiangle absorption photometry (MAAP) and the soot mass concentration determined by Raman spectroscopy. The Raman method is sensitive to graphitic structures present in the particle samples and was calibrated in the laboratory using Printex®90 model particles. Mass absorption cross sections were determined for a number of seven observation sites, ranging between 3.9 and 7.4 m2 g−1depending on measurement site and observational period. The highest values were found in a continentally aged air mass in winter, where soot particles were assumed to be mainly internally mixed. Our values are in the lower range of previously reported values, possibly due to instrumental differences to the former photometer and mass measurements. Overall, a value of 5.3m2 g−1from orthogonal regression over all samples is considered to be representative for the soot mass absorption cross section in the troposphere over Central Europe.
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

The 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

The 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

Elliptical 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.
Measurements of the pore‐scale water flow through snow using Fluorescent Particle Tracking Velocimetry
Authors: Walter B. , Horender S. , Gromke C. , Lehning M.
Published: October 2013

Fluorescent Particle Tracking Velocimetry (FPTV) measurements of the pore‐scale water flow through the pore space of a wet‐snow sample are presented to demonstrate the applicability of this measurement technique for snow. For the experiments, ice‐cooled water seeded with micron sized fluorescent tracer particles is either sprinkled on top of a snow sample to investigate saturated and unsaturated gravity‐driven flow or supplied from a reservoir below the snow sample to generate upward flow driven by capillary forces. The snow sample is illuminated with a laser light sheet and the fluorescent light of the particles transported with the water in the pore space is recorded with a high‐speed camera equipped with an optical filter. Tracking algorithms are applied to the images to obtain flow paths and flow velocities. A flow loop found in a pore space for the case of saturated gravity flow together with the tortuosity of the particle trajectories indicate the three‐dimensionality of the water flow in wet snow. The average vertical flow velocities in the pore spaces were 11.2 mm s−1 for the downward saturated gravity flow and 9.6 mm s−1 for the upward flow that is driven by capillary forces for the limited cases presented as examples of the measurement technique. In the case of unsaturated gravity‐driven flow, the average and the maximum flow velocities were found to be 30 times smaller than for the saturated gravity flow. Velocity histograms show that the fraction of the total water flowing against the main flow direction was about 3–5%, and that the horizontal velocities average to zero for both the saturated gravity‐driven and the capillary flow.
Using a Kinase‐Inducible Bimolecular Switch to Control Enzyme Activity in Living Cells
Authors: Mehta Sohum , Zhang Jin
Published: October 2013

Molecular 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

In 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

Objectives

Pica 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.

Methods

The 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.

Results

Study 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.

Conclusions

This 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

Objective

Osteoporosis 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.

Methods

We 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.

Results

The 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.

Conclusions

Our 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

Objectives

The 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.

Methods

Participants 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.

Results

Relatively 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.

Conclusions

This 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.
The vocal repertoire of adult male blue monkeys (Cercopithecus mitis stulmanni): A quantitative analysis of acoustic structure
Authors: Fuller James Lewis
Published: October 2013

Vocal signals are key elements in understanding species' behavior, sociality, and evolution. Quantified repertoires serve as foundations for investigating usage and function of particular signals, and also provide a basis for comparative analyses among individuals, populations, and taxa to explore how entire signal systems evolve. This study presents a descriptive catalogue of all vocal signals used by adult male blue monkeys (Cercopithecus mitis stuhlmanni). During 12 months in the Kakamega Forest, Kenya, I observed and digitally recorded vocal behavior of 32 adult males across a variety of socioecological contexts. From recordings, I measured 18 temporal‐frequency parameters. Undirected ordination and hierarchical cluster analysis identified six distinct call types regularly used by males: ant, boom, ka, katrain, nasal scream, and pyow. Cross‐validated discriminant function analysis supported the classifications. The repertoire is best described as discrete, though some gradation occurs between pyows and ants. Summary of acoustic structure and exemplar spectrograms are provided for each call type, along with preliminary examination of socioecological contexts in which they were produced. Discussion addresses repertoire structure, similarity to other taxa, and potential for functional inferences. Am. J. Primatol. 9999:1–14, 2013. © 2013 Wiley Periodicals, Inc.
Technical Note: Virtual reconstruction of KNM‐ER 1813 Homo habilis cranium
Authors: Benazzi Stefano , Gruppioni Giorgio , Strait David S. , Hublin Jean‐Jacques
Published: October 2013

A very limiting factor for paleoanthropological studies is the poor state of preservation of the human fossil record, where fragmentation and deformation are considered normal. Although anatomical information can still be gathered from a distorted fossil, such specimens must typically be excluded from advanced morphological and morphometric analyses, thus reducing the fossil sample size and, ultimately, our knowledge of human evolution. In this contribution we provide the first digital reconstruction of the KNM‐ER 1813 Homo habilis cranium. Based on state of‐the‐art three‐dimensional digital modeling and geometric morphometric (GM) methods, the facial portion was aligned to the neurocranium, the overall distortion was removed, and the missing regions were restored. The reconstructed KNM‐ER 1813 allows for an adjustment of the anthropometric measurements gathered on the original fossil. It is suitable for further quantitative studies, such as GM analyses focused on skull morphology or for finite element analysis to explore the mechanics of early Homo feeding behavior and diet. Am J Phys Anthropol 153:154–160, 2014. © 2013 Wiley Periodicals, Inc.