bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between splenic, renal, gastric and cardiac sonographic and post-mortem measurements in horses
Authors: Navas de Solis C. , Foreman J.H. , Byron C.R. , Carpenter R.E.
Published: March 2012

The relationships between spleen size and the size of kidney, stomach, and heart were studied ultrasonographically. Kidney was studied as a non-mobile internal reference standard. Stomach has been reported to alter spleen size with changing stomach diameter. Heart would logically be hypothesized to correlate with spleen size as measure of athleticism. Standard echocardiograms, sonographic andpost-mortemsplenic, renal and gastric measurements were obtained from 8 donated horses. Splenic measurements were obtained at baseline and after administration of epinephrine and detomidine (separately) to mimic maximal and resting sympathetic tone and obtain minimal and maximal splenic size, respectively. No significant correlations (r<0.5,P≯0.05) were observed between the sonographic orpost-mortemsplenic measurements and sonographic orpost-mortemrenal measurements. Sonographically-estimated andpost-mortemspleen volume were correlated with the sonographic (r=0.89,P=0.003) andpost-mortemstomach length (r=0.77,P=0.02). Sonographic andpost-mortemgastric measurements were not strongly correlated. Baseline (before administration of drugs) sonographically-estimated volume of the spleen was not strongly correlated with echocardiographic orpost-mortemcardiac measurements. Sonographically-estimated splenic volume after detomidine administration was correlated with left ventricular weight (r=0.82,P=0.01). Thepost-mortemvolume of the spleen was moderately correlated with aortic root diameter (r=0.75,P=0.03) and the correlation approached significance for heart weight (r=0.7,P=0.055). The spleen-to-kidney ratio is unlikely to be useful in assessing splenomegaly in horses. Further studies are needed to assess the accuracy of the sonographic method to measure the kidneys, stomach and the effect of gastric filling on splenic size. Assessment of the interactions between cardiac size, splenic size, and athletic ability would be an interesting corollary to this experiment.
Características y disparidades entre sub-especialidades: un estudio de caso con grupos de Biotecnología
Authors: Morillo Fernanda , Aparicio Javier
Published: March 2012

El objetivo de este trabajo es el estudio de las características y disparidades entre las sub-especialidades existentes dentro de categorías interdisciplinares, planteando la necesidad de identificar y evaluar por separado cada una de ellas. Se analizan los años 2003-2006, a través de las bases de datos del Web of Science (WoS), y se exploran las posibles diferencias entre grupos de investigación de Biotecnología de la Comunidad de Madrid según su perfil de especialización. Esta región española es la de mayor producción en Biotecnología (27%) y dicha categoría presenta interacciones con otras disciplinas como Microbiología, Bioquímica y Alimentos. Por este motivo, el estudio de grupos incluye, en un segundo análisis, no sólo los documentos de esta categoría, sino también todas las publicaciones de los investigadores principales, independientemente de su disciplina. Con estos datos, se examina la influencia de la especialización en las características de los grupos, sus patrones de colaboración y su impacto. Se identifican tres tipologías según las sub-especialidades: a) grupos del NÚCLEO (publicando el 50% o más de sus documentos en Biotecnología); b) grupos de tipo BÁSICO (publicando en Bioquímica y otras disciplinas básicas), y c) grupos de tipo MEDIO (publicando en Alimentos y disciplinas menos básicas). Por medio de pruebas estadísticas, se encontraron diferencias significativas entre estos conjuntos en relación con su producción e impacto. Se concluye que estas disparidades deberían ser tenidas en cuenta al evaluar la investigación que se produce en categorías interdisciplinares como la Biotecnología.
Administración electrónica en las universidades públicas españolas
Authors: Rocha Rocío , Cobo Ángel , Alonso Margarita
Published: March 2012

En este trabajo se analiza el nivel de penetración de la administración electrónica en el sistema universitario español a través de una evaluación heurística de las sedes electrónicas universitarias. Estas sedes se convierten en un elemento clave en los procesos de difusión de información y prestación de servicios electrónicos propios de una administración pública. Del trabajo se desprende una buena predisposición de las universidades ante la e-administración aunque su evolución aún no ha alcanzado unos niveles óptimos. Igualmente se analizan las principales características diferenciadoras de las instituciones de educación superior con respecto a otras administraciones y sus implicaciones desde el punto de vista de la administración electrónica.
Stress induced anisotropy and applied field dependence of second order perturbed energy of thick ferromagnetic films
Authors: Samarasekara P.
Published: March 2012

The energy of thick ferromagnetic films up to 10000 layers has been explained in this report using classical Heisenberg Hamiltonian with second order perturbation. Especially the effect of applied magnetic field and stress on energy of sc(001) ferromagnetic thick films has been investigated. Under the influence of perpendicular magnetic field given by =  6, the sc(001) ferromagnetic film with 10000 layers can be easily oriented in 0.5 radians direction. The easy direction of sc(001) ferromagnetic film with 10000   layers was found to be 0.6  radians when the in-plane magnetic field of   = 4.2 is applied. Because the easy axis oriented magnetic films are useful in magnetic memory devices and monolithic microwave integrated circuits (MMIC), the determination of easy direction is important.  If the stress given by = 2.6 is applied in perpendicular direction to the film plane, the film can be easily oriented in direction of 3 radians. Energy under influence of perpendicular magnetic field is larger than the energy under the influence of in-plane magnetic field. After introducing the second order perturbation to the Heisenberg Hamiltonian, even some small variations of energy could be investigated as indicated in the graphs in this manuscript.Keywords:  Ferromagnetic materials, thick films, Heisenberg Hamiltonian, stress induced anisotropyDOI: http://dx.doi.org/10.4038/josuk.v6i0.4223J Sci.Univ.Kelaniya 6 (2011) : 77-84
Article Commentary: Researching Prescription Drug Misuse among First Nations in Canada: Starting from a Health Promotion Framework
Authors: Dell Colleen Anne , Roberts Gary , Kilty Jennifer , Taylor Kelli , Daschuk Mitch , Hopkins Carol , Dell Debra
Published: March 2012

The intentional misuse of psychotropic drugs is recognized as a significant public health concern in Canada, although there is a lack of empirical research detailing this. Even less research has been documented on the misuse of prescription drugs among First Nations in Canada. In the past, Western biomedical and individual-based approaches to researching Indigenous health have been applied, whereas First Nations’ understandings of health are founded on a holistic view of wellbeing. Recognition of this disjuncture, alongside the protective influence of First Nations traditional culture, is foundational to establishing an empirical understanding of and comprehensive response to prescription drug misuse. We propose health promotion as a framework from which to begin to explore this. Our work with a health promotion framework has conveyed its potential to support the consideration of Western and Indigenous worldviews together in an ‘ethical space’, with illustrations provided. Health promotion also allots for the consideration of Canada's colonial history of knowledge production in public health and supports First Nations’ self-determination. Based on this, we recommend three immediate ways in which a health promotion framework can advance research on prescription drug misuse among First Nations in Canada.
An investigation of submarine groundwater—borne nutrient fluxes to the west Florida shelf and recurrent harmful algal blooms
Authors: Smith Christopher G. , Swarzenski Peter W.
Published: March 2012

A cross‐shelf, water‐column mass balance of radon‐222 (222Rn) provided estimates of submarine groundwater discharge (SGD), which were then used to quantify benthic nutrient fluxes. Surface water and groundwater were collected along a shore‐normal transect that extended from Tampa Bay, Florida, across the Pinellas County peninsula, to the 10‐m isobath in the Gulf of Mexico. Samples were analyzed for 222Rn and radium‐223,224,226 (223,224,226Ra) activities as well as inorganic and organic nutrients. Cross‐shore gradients of 222Rn and 223,224,226Ra activities indicate a nearshore source for these isotopes, which mixes with water characterized by low activities offshore. Radon‐based SGD rates vary between 2.5 and 15 cm d−1 proximal to the shoreline and decrease offshore. The source of SGD is largely shallow exchange between surface and pore waters, although deeper groundwater cycling may also be important. Enrichment of total dissolved nitrogen and soluble reactive phosphorus in pore water combined with SGD rates results in specific nutrient fluxes comparable to or greater than estuarine fluxes from Tampa Bay. The significance of these fluxes to nearshore blooms of Karenia brevis is highlighted by comparison with prescribed nutrient demands for bloom maintenance and growth. Whereas our flux estimates do not indicate SGD and benthic fluxes as the dominant nutrient source to the harmful algal blooms, SGD‐derived loads do narrow the deficit between documented nutrient supplies and bloom demands.
Allometric scaling and taxonomic variation in nutrient utilization traits and maximum growth rate of phytoplankton
Authors: Edwards Kyle F. , Thomas Mridul K. , Klausmeier Christopher A. , Litchman Elena
Published: March 2012

Nutrient utilization traits can be used to link the ecophysiology of phytoplankton to population dynamic models and the structure of communities across environmental gradients. Here we analyze a comprehensive literature compilation of four traits: maximum nutrient uptake rate; the half‐saturation constant for nutrient uptake; the minimum subsistence quota, measured for nitrate and phosphate; and maximum growth rate. We also use these traits to analyze two composite traits, uptake affinity and scaled uptake affinity. All traits tend to increase with cell volume, except for scaled uptake affinity and maximum growth rate, which tend to decline with cell volume. Most scaling relationships are the same for freshwater and marine species, although important differences exist. Most traits differ on average between major taxa, but between‐taxon variation is nearly always due to between‐taxon variation in volume. There is some evidence for between‐trait correlations that could constrain trait evolution, but these correlations are difficult to disentangle from correlation driven by cell volume. These results should enhance the parameterization of models that use size or taxonomic group to structure physiological variation in phytoplankton communities.
The regional abundance and size distribution of lakes and reservoirs in the United States and implications for estimates of global lake extent
Authors: McDonald Cory P. , Rover Jennifer A. , Stets Edward G. , Striegl Robert G.
Published: March 2012

We analyzed complete geospatial data for the 3.5 million lakes and reservoirs larger than 0.001 km2, with a combined surface area of 131,000 km2, in the contiguous United States (excluding the Laurentian Great Lakes) and identified their regional distribution characteristics. For Alaska, we also analyzed (1) incomplete data that suggest that the state contains 1–2.5 million lakes larger than 0.001 km2 covering over 50,000 km2 and (2) localized high‐resolution (5 m) data that suggest that the number of very small water bodies (< 0.001 km2) may be comparable with the number of lakes > 0.001 km2 in some areas. The Pareto distribution cannot accurately describe the lake abundance‐size relationship across the entire size spectrum, and extrapolation of this density function to small size classes has likely resulted in the overestimation of the number of small lakes in the world. While small water bodies dominate in terms of numbers, they are not numerous enough to dominate in terms of surface area, as has been previously suggested. Extending our results to the global scale suggests that there are on the order of 64 million water bodies larger than 0.001 km2 in the world, with a total surface area of approximately 3.8 million km2.
Oceanographic regime shift during 1997 in Disko Bay, Western Greenland
Authors: Hansen Marc Overgaard , Nielsen Torkel Gissel , Stedmon Colin A. , Munk Peter
Published: March 2012

Data from a long time series of temperature, salinity, and nutrient measurements in Disko Bay (West Greenland) reveal a marked change in the water characteristics during recent years. Seasonal dynamics in the upper 150 m of the water column were highly affected by the seasonality in meteorological conditions, while the deeper water strata were more stable and were primarily influenced by large‐scale circulation patterns. There was a marked increase in the average water temperatures at 200‐m depth in spring 1997, with the long‐term average increasing from 1.30°C to 2.25°C. Weekly data from 1996 to 1997 show that the sudden change in bottom water occurred in April 1997, due to the inflow of a larger proportion of North Atlantic water, which propagated north along the coast before entering the bay. Further support for this inflow was found when tracing the relative proportion of Atlantic water in the bay, using inorganic nutrients. These changes in the oceanography of the bay will not only lead to further glacial retreat but will also affect the local marine ecosystem by changing the relative dominance of major copepod species that overwinter in bottom waters of the bay.
The comparison of MODIS-Aqua (C5) and CALIOP (V2 & V3) aerosol optical depth
Authors: Redemann J. , Vaughan M. A. , Zhang Q. , Shinozuka Y. , Russell P. B. , Livingston J. M. , Kacenelenbogen M. , Remer L. A.
Published: March 2012

Abstract. We assess the consistency between instantaneously collocated level-2 aerosol optical depth (AOD) retrievals from MODIS-Aqua (C5) and CALIOP (Version 2 & 3), comparing the standard MODIS AOD (MYD04_L2) data to the AOD calculated from CALIOP aerosol extinction profiles for both the previous release (V2) and the latest release (V3) of CALIOP data. Based on data collected in January 2007, we investigate the most useful criteria for screening the MODIS and CALIOP retrievals to achieve the best agreement between the two data sets. Applying these criteria to eight months of data (Jan, Apr, Jul, Oct 2007 and 2009), we find an order of magnitude increase for the CALIOP V3 data density (by comparison to V2), that is generally accompanied by equal or better agreement with MODIS AOD. Differences in global, monthly mean, over-ocean AOD (532 nm) between CALIOP and MODIS range between 0.03 and 0.04 for CALIOP V3, with CALIOP generally biased low, when all available data from both sensors are considered. Root-mean-squares (RMS) differences in instantaneously collocated AOD retrievals by the two instruments are reduced from values ranging between 0.14 and 0.19 using the unscreened V3 data to values ranging from 0.09 to 0.1 for the screened data. A restriction to scenes with cloud fractions less than 1% (as defined in the MODIS aerosol retrievals) generally results in improved correlation (R2>0.5), except for the month of July when correlations remain relatively lower. Regional assessments show hot spots in disagreement between the two sensors in Asian outflow during April and off the coast of South Africa in July.
Chemical characterization of springtime submicrometer aerosol in Po Valley, Italy
Authors: Saarikoski S. , Carbone S. , Decesari S. , Giulianelli L. , Angelini F. , Teinilä K. , Canagaratna M. , Ng N. L. , Trimborn A. , Facchini M. C. , Fuzzi S. , Hillamo R. , Worsnop D.
Published: March 2012

Abstract. The chemistry of submicron particles was investigated at San Pietro Capofiume (SPC) measurement station in the Po Valley, Italy, in spring 2008. The measurements were performed by using both off-line and on-line instruments. Organic carbon (OC) and elemental carbon, organic acids and biomass burning tracers were measured off-line by using a 24-h PM1 filter sampling. More detailed particle chemistry was achieved by using an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and analyzing the data by positive matrix factorization (PMF). Oxalic acid had the highest concentrations of organic acids (campaign-average 97.4 ng m−3) followed by methane sulfonic, formic, malonic, and malic acids. Samples were also analyzed for glyoxylic, succinic, azelaic and maleic acids. In total, the nine acids composed 1.9 and 3.8% of OC and water-soluble OC, respectively (average), in terms of carbon atoms. Levoglucosan concentration varied from 17.7 to 495 ng m−3 with the concentration decreasing in the course of the campaign most likely due to the reduced use of domestic heating with wood. Six factors were found for organic aerosol (OA) at SPC by PMF: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), nitrogen-containing OA (N-OA) and three different oxygenated OAs (OOA-a, OOA-b and OOA-c). Most of the OA mass was composed of OOA-a, HOA and OOA-c (26, 24 and 22%, respectively) followed by OOA-b (13%), BBOA (8%) and N-OA (7%). As expected, OOAs were the most oxygenated factors with organic matter:organic carbon (OM:OC) ratios ranging from 1.9 to 2.2. The diurnal variability of the aerosol chemical composition was greatly affected by the boundary layer meteorology. Specifically, the effect of the nocturnal layer break-up in morning hours was most evident for nitrate and N-OA indicating that these compounds originated mainly from the local sources in the Po Valley. For sulfate and OOA-a the concentration did not change during the break-up suggesting their origin to be mostly regional. That resulted in much more oxidized OA in the daytime mixing layer than in the nocturnal surface layer. In this study, the high mass resolution and source-related aerosol chemistry from the HR-ToF-AMS was combined with the filter measurements in a total new extent elucidating novel features and sources of organic aerosol in the Po Valley region.
Seasonal and annual variation of carbon dioxide surface fluxes in Helsinki, Finland, in 2006–2010
Authors: Järvi L. , Nordbo A. , Junninen H. , Riikonen A. , Moilanen J. , Nikinmaa E. , Vesala T.
Published: March 2012

Abstract. Five years of carbon dioxide exchange measured with the eddy covariance technique at the world's northernmost urban flux station SMEAR III located in Helsinki, Finland, were analyzed. The long-term measurements and high-latitude location enabled us to examine the seasonal and annual variations of CO2 exchange, and to identify different factors controlling the measured exchange. Furthermore, the advantage of the station is that the complex surrounding area enables us to distinguish three different surface cover areas than can be evaluated separately. We also tested different methods (artificial neural networks and median diurnal cycles) to fill gaps in CO2 flux time series and examined their effect on annual emission estimates. The measured fluxes were highly dependent on the prevailing wind direction with the highest fluxes downwind from a large road and lowest downwind from the area of high fraction of vegetation cover. On an annual level, the difference in CO2 emission of the two areas was 75% showing the impact of complex measurement surroundings in the flux measurements. Seasonal differences in the CO2 exchange downwind from the road were mainly caused by reduced traffic rates in summer, whereas in other directions seasonality was more determined by vegetation activity. Differences between the gap filling methods were small, but slightly better (0.6 μmol m−2 s−1 smaller RMSE) results were obtained when the artificial neural network with traffic counts was used instead of the without traffic network and method based on median diurnal cycles. The measurement site was a net carbon source with an average annual emission of 1760 g C m−2, with a biased error of 6.1 g C m−2 caused by the gap filling. The annual value varied 16% between the different years.
High resolution NO2 remote sensing from the Airborne Prism EXperiment (APEX) imaging spectrometer
Authors: Popp C. , Brunner D. , Damm A. , Van Roozendael M. , Fayt C. , Buchmann B.
Published: March 2012

Abstract. We present and evaluate the retrieval of high spatial resolution maps of NO2 vertical column densities (VCD) from the Airborne Prism EXperiment (APEX) imaging spectrometer. APEX is a novel instrument providing airborne measurements of unique spectral and spatial resolution and coverage as well as high signal stability. In this study, we use spectrometer data acquired over Zurich, Switzerland, in the morning and late afternoon during a flight campaign on a cloud-free summer day in June 2010. NO2 VCD are derived with a two-step approach usually applied to satellite NO2 retrievals, i.e. a DOAS analysis followed by air mass factor calculations based on radiative transfer computations. Our analysis demonstrates that APEX is clearly sensitive to NO2 VCD above typical European tropospheric background abundances (>1 × 1015 molec cm−2). The two-dimensional maps of NO2 VCD reveal a very plausible spatial distribution with strong gradients around major NOx sources (e.g. Zurich airport, waste incinerator, motorways) and low NO2 in remote areas. The morning overflights resulted in generally higher NO2 VCD and a more distinct pattern than the afternoon overflights which can be attributed to the meteorological conditions prevailing during that day (development of the boundary layer and increased wind speed in the afternoon) as well as to photochemical loss of NO2. The remotely sensed NO2 VCD are also highly correlated with ground-based in-situ measurements from local and national air quality networks (R=0.73). Airborne NO2 remote sensing using APEX will be valuable to detect NO2 emission sources, to provide input for NO2 emission modeling, and to establish links between in-situ measurements, air quality models, and satellite NO2 products.
Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model
Authors: Gnanadesikan A. , Dunne J. P. , John J.
Published: March 2012

Abstract. Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1) shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., suboxic) waters does not increase under global warming, as these waters actually become more oxygenated. We show that the rise in dissolved oxygen in the tropical Pacific is associated with a drop in ventilation time. A term-by-term analysis within the least oxygenated waters shows an increased supply of dissolved oxygen due to lateral diffusion compensating an increase in remineralization within these highly hypoxic waters. This lateral diffusive flux is the result of an increase of ventilation along the Chilean coast, as a drying of the region under global warming opens up a region of wintertime convection in our model. The results highlight the potential sensitivity of suboxic waters to changes in subtropical ventilation as well as the importance of constraining lateral eddy transport of dissolved oxygen in such waters.
The moisture response of soil heterotrophic respiration: interaction with soil properties
Authors: Moyano F. E. , Vasilyeva N. , Bouckaert L. , Cook F. , Craine J. , Curiel Yuste J. , Don A. , Epron D. , Formanek P. , Franzluebbers A. , Ilstedt U. , Kätterer T. , Orchard V. , Reichstein M. , Rey A. , Ruamps L. , Subke J.-A. , Thomsen I. K. , Chenu C.
Published: March 2012

Abstract. Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertainty of at least 4% in global soil carbon stock predictions by 2100. The necessity of improving the representation of this relationship in models has been highlighted in recent studies. Here we present a data-driven analysis of soil moisture-respiration relations based on 90 soils. With the use of linear models we show how the relationship between soil heterotrophic respiration and different measures of soil moisture is consistently affected by soil properties. The empirical models derived include main effects and moisture interaction effects of soil texture, organic carbon content and bulk density. When compared to other functions currently used in different soil biogeochemical models, we observe that our results can correct biases and reconcile differences within and between such functions. Ultimately, accurate predictions of the response of soil carbon to future climate scenarios will require the integration of soil-dependent moisture-respiration functions coupled with realistic representations of soil water dynamics.
Coupled CO2 and O2-driven compromises to marine life in summer along the Chilean sector of the Humboldt Current System
Authors: Mayol E. , Ruiz-Halpern S. , Duarte C. M. , Castilla J. C. , Pelegrí J. L.
Published: March 2012

Abstract. Carbon dioxide and coupled CO2 and O2-driven compromises to marine life were examined along the Chilean sector of the Humboldt Current System, a particularly vulnerable hypoxic and upwelling area, applying the Respiration index (RI = log10 pO2pCO2) and the pH-dependent aragonite saturation (Ω) to delineate the water masses where aerobic and calcifying organisms are stressed. As expected, there was a strong negative relationship between oxygen concentration and pH or pCO2 in the studied area, with the subsurface hypoxic Equatorial Subsurface Waters extending from 100 m to about 300 m depth and supporting elevated pCO2 values. The lowest RI values, associated to aerobic stress, were found at about 200 m depth and decreased towards the Equator. Increased pCO2 in the hypoxic water layer reduced the RI values by as much as 0.59 RI units, with the thickness of the upper water layer that presents conditions suitable for aerobic life (RI>0.7) declining by half between 42° S and 28° S. The intermediate waters hardly reached those stations closer to the equator so that the increased pCO2 lowered pH and the saturation of aragonite. A significant fraction of the water column along the Chilean sector of the Humboldt Current System suffers from CO2–driven compromises to biota, including waters corrosive to calcifying organisms, stress to aerobic organisms or both. The habitat free of CO2-driven stresses was restricted to the upper mixed layer and to small water parcels at about 1000 m depth. Overall pCO2 acts as a hinge connecting respiratory and calcification challenges expected to increase in the future, resulting in a spread of the challenges to aerobic organisms.
Mats of psychrophilic thiotrophic bacteria associated with cold seeps of the Barents Sea
Authors: Grünke S. , Lichtschlag A. , de Beer D. , Felden J. , Salman V. , Ramette A. , Schulz-Vogt H. N. , Boetius A.
Published: March 2012

Abstract. This study investigated the bacterial diversity associated with microbial mats of polar deep-sea cold seeps. The mats are associated with high upward fluxes of sulfide produced by anaerobic oxidation of methane, and grow at temperatures close to the freezing point of seawater. They ranged from small patches of 0.2–5 m in diameter (gray mats) to extensive fields covering up to 850 m2 of seafloor (white mats) and were formed by diverse sulfide-oxidizing bacteria differing in color and size. Overall, both the dominant mat-forming thiotrophs as well as the associated bacterial communities inhabiting the mats differed in composition for each mat type as determined by microscopy, 16S rRNA gene sequencing and Automated Ribosomal Intergenic Spacer Analysis. While the smaller gray mats were associated with a highly diverse composition of sulfide oxidizers, the large white mats were composed of only 1–2 types of gliding Beggiatoa filaments. Molecular analyses showed that most of the dominant mat-forming sulfide oxidizers were phylogenetically different from, but still closely related to thiotrophs known from warmer ocean realms. The psychrophilic nature of the polar mat-forming thiotrophs was tested by visual observation of active mats at in situ temperature compared to their warming to >4 °C. The temperature range of mat habitats and the variation of sulfide and oxygen fluxes appear to be the main factors supporting the diversity of mat-forming thiotrophs in cold seeps at continental margins.
SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds – the two-CN system approach
Authors: Soulis K. X. , Valiantzas J. D.
Published: March 2012

Abstract. The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN parameter values corresponding to various soil, land cover, and land management conditions can be selected from tables, but it is preferable to estimate the CN value from measured rainfall-runoff data if available. However, previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. Hence, they suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of soils and land cover spatial variability on its hydrologic response is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behaviour of the CN-rainfall function produced by the simplified two-CN system is approached theoretically, it is analysed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous methods based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.
Integrated hydrological modelling of small- and medium-sized water storages with application to the upper Fengman Reservoir Basin of China
Authors: Zhang C. , Peng Y. , Chu J. , Shoemaker C. A.
Published: March 2012

Abstract. Hydrological simulation in regions with a large number of water storages is difficult due to the inaccurate water storage data, including both topologic parameters and operational rules. To address this issue, this paper presents an improved version of SWAT2005 (Soil and Water Assessment Tool, version 2005) using the satellite-based dataset Landsat, an empirical storage classification method, and some empirical relationships to estimate water storage and release from the various levels of flow regulation facilities. The improved SWAT2005 is characterised by three features: (1) a realistic representation of the relationships between the water surface area and volume of each type of water storage, ranging from small-sized ponds for water flow regulation to large-sized and medium-sized reservoirs for water supply and hydropower generation; (2) water balance and transport through a network combining both sequential and parallel streams and storage links; and (3) calibrations for the physical parameters and the human interference parameters. Both the original and improved SWAT2005 are applied to the upper Fengman Reservoir Basin, and the results of these applications are compared. The improved SWAT2005 accurately models small- and medium-sized storages, indicating a significantly improved performance from that of the original model in reproducing streamflows.
Rectification of the ancient geographic coordinates in Ptolemy's Geographike Hyphegesis
Authors: Marx C.
Published: March 2012

Abstract. A multitude of the ancient places given by Ptolemy in his Geography (~150 AD) are so far unknown. One of the main problems of their identification are the errors of the given ancient coordinates. The different kinds of errors are illustrated by examples. A new geodetic-statistical analysis method is described, by which groups of places with homogeneous systematic errors and places with gross errors can be determined. Based on a transformation function describing the systematic errors, presumable modern coordinates of unknown places can be computed. That, in conjunction with further information, can make possible their identification. A test of the analysis method is carried out on a complex simulated example and shows its practicability. The analysis method has been applied within an interdisciplinary research project on Ptolemy's Geography. Further developments of the method are imaginable to make it accessible for related data diagnostics.
Observed response of the marine atmospheric boundary layer to the Southern Ocean fronts during the IPY BGH 2008 cruise
Authors: Messager C. , Speich S. , Key E.
Published: March 2012

Abstract. A set of meteorological instruments was added to an oceanographic cruise crossing the Southern Ocean from Cape Town to 57°33' S on board the R/V Marion Dufresne during the summer 2008. The Cape Cauldron, the subtropical, subantarctic, polar and southern Antarctic circumpolar current fronts were successively crossed. The recorded data permitted to derive the exchange of momentum, heat and water vapour at the ocean-atmosphere interface. A set of 38 radiosonde releases complemented the dataset. The marine atmospheric boundary layer characteristics and air-sea interaction when ship crossed the fronts and eddies are discussed. The specific role of the atmospheric synoptic systems advection on the air-sea interaction is highlighted over these regions. The dynamic associated with these systems drive the vertical mixing of the MABL by wind shear effect and/or the vertical thermal mixing. The MABL is stabilized (destabilized) and mixing is inhibited (enhanced) over the warm front sides if meridional wind component is northerly (southerly).
Assessment of the Heart Failure Pharmacotherapy of Patients with Continuous Flow Left-Ventricular Assist Devices
Authors: Jennings Douglas L. , Jones Mathew C. , Lanfear David E.
Published: March 2012

Purpose

The purpose of this project was to characterize the use of heart failure medications during the first year after left-ventricular assist device (LVAD) implantation.

Methods

All patients who received a HeartMate II at our institution between January 1, 2007, and August 1, 2009, and were followed by our multidisciplinary team for at least 6 months were eligible for inclusion. Use of heart failure medications, including dosages, was collected for each patient prior to LVAD implantation, at time of discharge, and at each subsequent monthly office visit for up to 1 year after implantation. The primary end point was the prescription rate for each medication class at discharge. Secondary end points included the use and dosage of these agents during follow up.

Results

A total of 28 patients were included (mean age = 50±11.5 years; sex 75% male; race 57.1% white; bridge-to-transplant rate 25%). There was a statistically significant decrease in use of digoxin (42.9% vs. 7.1%), spironolactone (50% vs. 17.9%), nitrates (39.3% vs. 7.1%), and milrinone (71.4% vs. 3.6%) postimplantation compared with baseline (p<0.05, for all comparisons). More than 50% of patients received vasodilators, beta-blockers, and hydralazine both preimplantation and postimplantation (p>0.05 for each class). Furthermore, more patients reached target doses of beta-blockers (0% vs. 28.6%; p=0.04) after LVAD implantation.

Conclusion

Our pilot study shows consistent prescription of heart failure pharmacotherapy in LVAD patients at our institution, with more patients able to tolerate target doses of beta-blockers.
Oxidative Stress Markers in Hemodialysis and Peritoneal Dialysis Patients, Including Coenzyme Q10 and Ischemia-Modified Albumin
Authors: Mehmetoglu Idris , Hümeyra Yerlikaya F. , Kurban Sevil , Sami Erdem S. , Tonbul Zeki
Published: March 2012

Objectives

Oxidative stress results from an imbalance between the production of free radicals and antioxidant activity. There is wide agreement that patients undergoing regular dialysis treatment experience increased oxidative stress. The aim of this study was to investigate serum total antioxidant status (TAS), total oxidant status (TOS), ischemia-modified albumin (IMA), and coenzyme Q10 (CoQ10) levels in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients, compared with controls.

Methods

This study was performed on 41 (21 men, 20 women) CAPD patients, 38 (20 men,18 women) HD patients, and 43 (23 men, 20 women) healthy control subjects. CoQ10 levels were standardized using blood lipids.

Results

Serum TAS levels and CoQ10/total cholesterol values of the HD and CAPD patients were significantly lower, whereas serum IMA and TOS levels were significantly higher, than those of controls. Furthermore, CoQ10/LDL, CoQ10/triglycerides, and CoQ10/total cholesterol + triglycerides values of the CAPD patients were significantly lower than those of controls. No differences were found between serum IMA, TAS, TOS, CoQ10 levels, and adjusted CoQ10 values of the CAPD and HD patients.

Conclusions

Our results suggest that oxidative stress is increased in HD and CAPD patients compared with controls, as proven by decreased TAS and adjusted CoQ10 levels and increased TOS and IMA levels. Therefore, an antioxidant supplementation to these patients may be suggested.
Extracellular Volume Expansion in Peritoneal Dialysis Patients
Authors: Fan Stanley , Sayed Rabya H. , Davenport Andrew
Published: March 2012

Introduction:

Cardiovascular mortality remains high among peritoneal dialysis (PD) patients. Several small studies have suggested that PD patients are volume expanded, and as such this could be a cardiovascular risk factor. We therefore wished to investigate factors which could lead to extracellular water (ECW) expansion.

Methods:

Retrospective cross-sectional audit of 600 prevalent, adult PD patients attending two tertiary university PD centers, with corresponding assessments of PD adequacy, transport status, and multifrequency bioimpedance measurements of extracellular water to total body water (ECW/TBW).

Results:

600 PD patients, median age 57.5 (46.9–67.9) years, 54% male, 31% diabetic, 47.6% Caucasoid, median PD vintage 16 (3.7–38) months, (64% prescribed icodextrin, 34% hypertonic glucose dialysates, and 74% antihypertensive medications). Mean ECW 15.1±0.2 L, ICW 20±0.2 L, ECW/TBW ratio 0.437±0.007. On multivariate analysis %ECW/TBW was associated with age (F=13.1 β=0.045 p=0.000), number of antihypertensive medications (F=10.3 β=0.43 p=0.001), log CRP (F=12.9 β=1.3 p=0.000), and negatively with serum albumin (F=25 β=-0.22 p=0.000), and residual renal function (urine volume mL F=9.96 β=-0.001 p=0.002) (weekly Kt/Vurine F=8.82 β=-2.05, p=0.003).

Conclusions:

Overhydration as assessed by ECW/TBW is prevalent in adult PD patients, and is associated with loss of residual renal function, inflammation, malnutrition and hypertension – as assessed by antihypertensive medications. As this was a retrospective cross-sectional audit, whether loss of residual renal function, inflammation, and protein energy wasting lead to volume expansion remains to be determined in prospective longitudinal studies.
Programming and reprogramming: new approaches for understanding disease
Authors: Cowan Chad
Published: March 2012

Our research is focused on understanding the contribution of environmental and genetic factors in the development of obesity and obesity related diseases. We seek to gain a better understanding of these diseases by capturing the disease genotype through the creation of induced pluripotent patient-specific stem cells. These cells can then be used to interrogate the disease phenotype in differentiated adult cells types associated with or affected by disease. By comparing cells from healthy donors and obese donors we hope to discover the cellular origins of obesity and use this information to aid in the battle against this and related metabolic diseases. Our progress towards this goal will be the topic of my presentation.
A Chemical Approach to Efficient Generating Embryonic and Germline-derived Pluripotent Stem Cells
Authors: Baharvand Hossein
Published: March 2012

Since the first report on the generation of pluripotent embryonic stem cells (ESCs) from preimplantation embryos, there has been tremendous interest in developing culture systems to produce ESCs from human and other species efficiently to use them in biomedical applications. These cells have provided fascinating possibilities and tools to study human development, genetic diseases, and development of toxicological and pharmaceutical applications as well as in therapeutic transplantation. Developing an efficient method to derive ESCs from various genetic backgrounds should be valuable for establishment of ESCs in various mammalian species, including human. However, it is still encumbered by various technical and ethical objections. This challenge is circumvented by using small molecules that suppress differentiation pathways. Here, we will present our recent studies on efficient and reproducible establishment of ESCs from blastocysts and single blastomere to avoid destruction of the embryo. Additionally, we present our recent researches on testis-derived pluripotent stem cells that share characteristics of ESCs. The application of these small molecules will not only solve the problems of derivation and expansion of pluripotent stem cell in defined conditions, but also clarify new signaling pathways in them.
Essential role of p-selectin in endothelial progenitor cells-induced inhibition of platelet aggregation and thrombus formation
Authors: Saleh Haitham Abou
Published: March 2012

We have previously shown that Endothelial Progenitor Cells (EPCs) bind and inhibit platelet function and impair thrombus formation, but the surrounding mechanisms that regulate this process have not been fully described. Herein, we addressed the mechanistic action of EPCs on platelet-thrombus formation and we highlighted the role of platelet P-selectin in this process.

EPCs were generated from human peripheral blood mononuclear cells after 10 days of culture on fibronectin in conditioned media. The impact of EPCs on platelet aggregation and thrombus formation was investigated in P-selectin deficient (P-sel-/-) and their wild-type counterpart (WT) mice. EPCs significantly impaired, in a concentration dependent-manner, collagen-induced whole blood platelet aggregation in WT mice; whereas in P-sel-/- mice, EPCs had no significant effect. Moreover, in ferric chloride-injured arterial thrombosis model, infusion of EPCs significantly reduced thrombus formation in WT, but not in P-sel-/- mice. Furthermore, the number of EPCs recruited within the thrombi and along the arterial wall was reduced in P-sel-/- mice as compared to WT mice, and the relative mass of thrombi generated in EPC-treated P-sel-/- mice was significantly larger than that in EPC-treated WT mice.

EPCs impair platelet aggregation and reduce thrombus formation by a cellular mechanism implying binding to platelet P-selectin. These findings add new insights into the role of EPCs in the regulation of platelet function and thrombotic reaction during vascular repair.
Approximate Solutions to Time-Fractional Schrödinger Equation via Homotopy Analysis Method
Authors: Khan Najeeb Alam , Jamil Muhammad , Ara Asmat
Published: March 2012

We construct the approximate solutions of the time-fractional Schrödinger equations, with zero and nonzero trapping potential, by homotopy analysis method (HAM). The fractional derivatives, in the Caputo sense, are used. The method is capable of reducing the size of calculations and handles nonlinear-coupled equations in a direct manner. The results show that HAM is more promising, convenient, efficient and less computational than differential transform method (DTM), and easy to apply in spaces of higher dimensions as well.
Cure Kinetics and Activation Energy Studies of Modified Bismaleimide Resins
Authors: Chandran M. Satheesh , Krishna M. , Rai Sheshappa , Krupashankara M. S. , Salini K.
Published: March 2012

The cure kinetics and activation energy (Ea) of bismaleimide homopolymer and modified bismaleimide resin systems with different chain extenders were investigated. The bismaleimide resin under investigation was bismaleimidodiphenyl methane (BMPM) and the chain extenders were (i) O-O′ diallyl bisphenol A (DABA) and (ii) methylenedianiline (MDA). Dynamic multiheating DSC method was used to study the kinetics of the curing process. Activation energies were determined for both unmodified and modified resins from nonisothermal multiheating rate DSC tests by using Ozawa and Kissinger models. Activation energy for BMPM homopolymer increased from 95 kJ/mol to 125 kJ/mol as a function of conversion. For the MDA-modified system the activation energy was independent of percentage conversion, at 108 kJ/mol. In the case of DABA-modified bismaleimide the activation energy increased steadily at 6 kJ/mol from 10 to 100% conversion.
Directional Photofluidization Lithography: Micro/Nanostructural Evolution by Photofluidic Motions of Azobenzene Materials
Authors: Lee Seungwoo , Kang Hong Suk , Park Jung‐Ki
Published: March 2012

This review demonstrates directional photofluidization lithography (DPL), which makes it possible to fabricate a generic and sophisticated micro/nanoarchitecture that would be difficult or impossible to attain with other methods. In particular, DPL differs from many of the existing micro/nanofabrication methods in that the post‐treatment (i.e., photofluidization), after the preliminary fabrication process of the original micro/nanostructures, plays a pivotal role in the various micro/nanostructural evolutions including the deterministic reshaping of architectures, the reduction of structural roughness, and the dramatic enhancement of pattern resolution. Also, DPL techniques are directly compatible with a parallel and scalable micro/nanofabrication. Thus, DPL with such extraordinary advantages in micro/nanofabrication could provide compelling opportunities for basic micro/nanoscale science as well as for general technology applications.