bluuebunny/crossref_metadata_2025 huggingface dataset:
Singapour – Maintenir l'équilibre entre la prospérité, la croissance sociale et la démocratisation graduelle
Authors: Singh Bilveer
Published: April 2011

Résumé Depuis qu’elle a obtenu son indépendance politique en août 1965, Singapour a connu un développement phénoménal à tous les points de vue. Cette cité-État, à l’origine très peu développée, est devenue aujourd’hui une métropole ultramoderne qui possède un des revenus par habitant les plus élevés du monde. À côté de sa propreté et de son efficacité, Singapour est également l’un des pays les moins corrompus du monde. Toutefois, même si elle a quitté le tiers-monde pour devenir, sur le plan économique, un État du monde industrialisé, son développement sur le plan politique a été relativement lent. Les détracteurs ont dénigré la manière dont le parti au pouvoir, qui domine la politique nationale depuis plus de cinquante ans, continue à bloquer la démocratisation politique en déployant une série de mesures destinées à tenir l’opposition à l’écart et à limiter la libération politique. Comment un État économiquement prospère est-il parvenu à s’opposer à une démocratisation politique à grande échelle, dans la mesure où il est en relation avec le monde entier et se situe dans une région qui a vu disparaître les régimes autoritaires. La réponse se trouve dans l’aptitude du parti dirigeant à assurer la prospérité économique et la sécurité, et à créer, par un processus graduel de démocratisation et de responsabilité, un système qui est synonyme de bonne gouvernance dans un contexte asiatique.
La démocratie en Amérique latine
Authors: Ducatenzeiler Graciela , Itzcovitz Victoria
Published: April 2011

Résumé C’est à partir des années 1980 que l’Amérique latine, après un XXe siècle plutôt turbulent, se réconcilie avec la démocratie. On assiste à l’apparition d’un mouvement singulier et notable qui se fera rapidement connaître comme celui des nouvelles gauches latino-américaines. Cependant, les formes politiques adoptées en Argentine, en Bolivie, au Brésil, au Chili, en Équateur, en Uruguay et au Venezuela demeurent très différentes. Dans cet article, nous traçons un panorama des « gauches » latino-américaines et leurs relations avec la démocratie républicaine. Nous analysons particulièrement le cas argentin tout en débattant de l’utilité du concept pour caractériser ce phénomène politique.
Politiques de l'emploi : une analyse des transformations de l'action publique en Wallonie et en France
Authors: Berthet Thierry , Conter Bernard
Published: April 2011

Résumé Cet article porte sur l’analyse des changements à l’œuvre dans les politiques territoriales de l’emploi en France et en Belgique. Il s’appuie sur un modèle d’analyse croisant les principales composantes des politiques publiques et des logiques d’action sectorielles. À l’aide de celui-ci, les auteurs proposent une lecture comparée et une mesure des changements à l’œuvre dans ce secteur d’action publique dans un contexte d’européanisation croissante qui promeut une plus grande territorialisation de l’action publique, une responsabilisation accrue des individus et le développement de partenariats publics/privés dans la mise en œuvre des dispositifs publics.
The prehistory of mycotoxins: related cases from ancient times to the discovery of aflatoxins
Authors: Ramos A. , Sanchis V. , Marín S.
Published: April 2011

This paper presents a journey through the known and the presumed history of two important mycotoxicoses which
played an important role in the history of mankind before aflatoxins were discovered: (1) ergotism, also known as St.
Anthony's fire or Holy Fire, linked to the consumption of cereals (especially rye) contaminated by the hallucinogenic
and vasoconstrictor alkaloids produced by the Claviceps purpurea ergot, whose presence in Europe during the Middle
Ages was considered epidemic, and (2) the so-called alimentary toxic aleukia (also known by its English acronym
ATA), caused by the trichothecenes produced by Fusarium sporotrichioides and Fusarium poae, which devastated
a large part of Russia shortly before the characterisation of the toxins of Aspergillus flavus.
Effect of glucomannan on haematological, coagulation and biochemical parameters in male rabbits fed aflatoxin-contaminated ration
Authors: Eisa A. , Metwally A.
Published: April 2011

The main goal of the present work was to explore the effect of glucomannan (GM) as a biological detoxifying agent
on haematological, coagulation and biochemical parameters in male rabbits fed aflatoxin B1 (AFB1)-contaminated
ration. Thirty male White New Zealand rabbits were used in this study. They were divided into 3 equal groups. The
first group was given a ration free from mycotoxins and kept as a control group. Rabbits in the second group were
fed a ration naturally contaminated with AFB1 (0.1 mg/kg ration) for 28 days, while rabbits in the third group were
fed AFB1-contaminated ration (0.1 mg/kg ration) in addition to GM (1 kg/ton) for 28 days. The results of the present
work revealed that aflatoxicosis elicited a picture of microcytic hypochromic anaemia, leukopenia, lymphocytopenia
and monocytopenia. Coagulopathy recorded in this work due to aflatoxicosis was characterised by thrombocytopenia,
prolonged prothrombin time and activated partial thromboplastin time. Hepatotoxicity due to AFB1 recorded in
this work was characterised by a significant increase in serum activity of alanine aminotransferase, gammaglutamyl
transferase and total bilirubin in addition to a significant decrease in serum total proteins and albumin. Data recorded
in this work showed a significant increase in serum urea, creatinine, total lipids and cholesterol in addition to a
significant decrease in serum glucose, calcium, phosphorus and iron in rabbits fed aflatoxin-contaminated ration
only. Supplementation of rabbit ration with GM resulted in the return of the above-mentioned parameters to normal
control values. It could be concluded that GM provides new insights into counteracting the adverse effects of AFB1.
Physiological Characterization of Hatchery-Origin Juvenile SteelheadOncorhynchus mykissAdopting Divergent Life-History Strategies
Authors: Hanson Kyle C. , Gale William L. , Simpson William G. , Kennedy Benjamen M. , Ostrand Kenneth G.
Published: April 2011

Smoltification by juvenile Pacific salmonids has been described as a developmental conflict whereby individuals face several life-history decisions. Smoltification occurs as a result of interactions between organismal condition and environmental cues, although some fish may forgo ocean migration and remain in freshwater streams for some time (residualize). We compared the physiological profiles of steelhead that were actively migrating to the ocean (migratory fish) and those that remained in fresh water (residuals) for at least a period of between 2 wk and 3 mo after release from a hatchery facility. In addition, we investigated the physiological characterization of residuals that further differentiated into precocial freshwater residents or parr that will either precocially mature in fresh water or migrate to the ocean in the future. Residuals had higher condition factors and gonadosomatic index than migratory fish and were characterized as less prepared for saltwater due to low levels of gill Na+,K+-ATPase activity and Na+,K+-ATPase α1b-subunit expression. Residuals tended to be males with the highest condition factors. Sex-specific differences are probably reflective of male fish adopting an alternative life-history strategy foregoing outmigration as a result of condition at the time of release. Collection of residuals throughout the fall suggested that residual hatchery fish further diversify into precocially mature fish that will presumably attempt to spawn without ever migrating to the ocean or into parr that will precocially mature or migrate in a future year.
Participation of the Receptor for Advanced Glycation End Products in Efferocytosis
Authors: Friggeri Arnaud , Banerjee Sami , Biswas Subrata , de Freitas Andressa , Liu Gang , Bierhaus Angelika , Abraham Edward
Published: April 2011

Clearance of apoptotic cells by macrophages and other phagocytic cells, called efferocytosis, is a central process in the resolution of inflammation. Although the receptor for advanced glycation end products (RAGE) has been shown to participate in a variety of acute and chronic inflammatory processes in the lungs and other organs, a role for RAGE in efferocytosis has not been reported. In the present studies, we examined the potential involvement of RAGE in efferocytosis. Macrophages from transgenic RAGE−/− mice showed a decreased ability to engulf apoptotic neutrophils and thymocytes. Pretreatment of RAGE+/+ macrophages with advanced glycation end products, which competitively bind to RAGE, or Abs against RAGE diminished phagocytosis of apoptotic cells. Overexpression of RAGE in human embryonic kidney 293 cells resulted in an increased ability to engulf apoptotic cells. Furthermore, we found that incubation with soluble RAGE enhances phagocytosis of apoptotic cells by both RAGE+/+ and RAGE−/− macrophages. Direct binding of RAGE to phosphatidylserine (PS), an “eat me” signal highly expressed on apoptotic cells, was shown by using solid-phase ELISA. The ability of RAGE to bind to PS on apoptotic cells was confirmed in an adhesion assay. Decreased uptake of apoptotic neutrophils by macrophages was found under in vivo conditions in the lungs and peritoneal cavity of RAGE−/− mice. These results demonstrate a novel role for RAGE in which it is able to enhance efferocytosis through binding to PS on apoptotic cells.
APASL and AASLD Consensus Guidelines on Imaging Diagnosis of Hepatocellular Carcinoma: A Review
Authors: Tan Cher Heng , Low Su-Chong Albert , Thng Choon Hua
Published: April 2011

Consensus guidelines for radiological diagnosis of hepatocellular carcinoma (HCC) have been drafted by several large international working groups. This article reviews the similarities and differences between the most recent guidelines proposed by the American Association for Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver. Current evidence for the various imaging modalities for diagnosis of HCC and their relevance to the consensus guidelines are reviewed.
Mycobacterium bovisin Swine: Spoligotyping of Isolates from Argentina
Authors: Barandiaran Soledad , Martínez Vivot Marcela , Moras Eduardo Vicente , Cataldi Angel Adrián , Zumárraga Martín José
Published: April 2011

A total of 143Mycobacterium bovisisolates of pigs, from the most productive swine area in Argentina, were typed by spoligotyping. Twenty-two different spoligotypes were identified, and 133 (93%) isolates were grouped into 12 clusters. One of them, designed SB0140, was the most frequent because it held 83 (58%) isolates. This spoligotype also grouped 362 (43%) out of 841 isolates from previously typed cattle and, thus, constitutes the most frequent in our country. In addition, 135 (94%) isolates revealed spoligotypes identical to those of cattle, showing an epidemiological link. On the other hand, there were seven novel spoligotypes, six of which were also unique since they had only one isolate each. This study aimed to identify the spoligotypes ofM. bovisisolated from pigs to contribute to a better understanding of the distribution of bovine tuberculosis in the main productive area of Argentina.
Aging and exercise effects on motor learning and spatial memory
Authors: Kennard John , Woodruff-Pak Diana S.
Published: April 2011

The aim of this experiment was to determine whether low impact forced exercise improved learning and memory in middle aged and older mice. The effects of 12 weeks of low impact, forced running on motor learning and spatial memory were compared in 32 C57BL/6 mice in three age groups with a mean age of 13, 17, and 25 months. Motor learning was assessed with the rotorod, and spatial memory was assessed with the Morris water maze (MWM). Mice were randomly assigned to the forced exercise or sedentary control group and were treated for 60 min/day (2 30-min sessions) for 12 weeks. Significant age differences were observed on the rotorod (15 and 25 RPM) with the 13-month-old mice outperforming 17- and 25-month-old mice. Age differences were also observed on the MWM, with 25-month mice impaired in latency to escape and distance covered. The effect of exercise on rotorod performance did not attain statistical significance, but the mean performance of runners was higher than that of controls. Exercise improved spatial memory retention in the MWM and led to significant improvement in acquisition distance. Low impact forced exercise did not have strong effects on motor learning as assessed by the rotorod. However, low impact forced exercise did improve retention of spatial memory in 13-month-old mice. Slight improvements in spatial memory were seen in the oldest runners, though this experiment suggested that the beneficial effect of exercise and plasticity in memory was generally limited to 13-month-old middle aged mice, with significant age-related differences in motor and spatial learning occurring in the 4- month period between 13 and 17 months.
Quality of diet related to food insecurity and food stamps use among older people
Authors: Montoya Maria F , Hite Andre W , Rohrbeck Patricia , Bawa Binky , Akinwolemiwa Oladayo O , Benson Alicia M , Luna Hollen Mary , Reyes Ortiz Carlos A
Published: April 2011

We explore the association between quality of diet and food security status among older persons. Cross-sectional survey of large national samples, from the National Health & Nutrition Examination Surveys (1988-1994 & 2001-2002), in the United States. A total of 5,039 and 2,040 men and women aged 60 and older, respectively. The dependent variable was the healthy eating index (HEI; 2000 and 2005) as a measure of diet quality. The independent variable of interest was food security status and was categorized as food secure, food insecurity receiving food stamps and food insecurity not receiving food stamps. In multivariate analyses, food insecure individuals not receiving food stamps had lower total HEI-2000 scores compared to food secure individuals (b=-3.91, SE=1.81, P=0.0310). Factors independently associated with high HEI (2000 or 2005) scores were female gender, being married, highly educated or wealthy, with very good/ excellent perceived health, or without functional limitations. Food secure individuals had better quality of diet than food insecure individuals. Among food insecure individuals, receiving food stamps was not associated with diet quality. Food insecure families with older individuals may need new methods of dissemination of food and nutrition programs – methods that yield positive and promising changes in the health status of this special population group.
Tryptophan Transport in Human Fibroblast Cells—A Functional Characterization
Authors: Vumma Ravi , Johansson Jessica , Lewander Tommy , Venizelos Nikolaos
Published: April 2011

There are indications that serotonergic neurotransmission is disturbed in several psychiatric disorders. One explanation may be disturbed transport of tryptophan (precursor for serotonin synthesis) across cell membranes. Human fibroblast cells offer an advantageous model to study the transport of amino acids across cell membranes, since they are easy to propagate and the environmental factors can be controlled. The aim of this study was to functionally characterize tryptophan transport and to identify the main transporters of tryptophan in fibroblast cell lines from healthy controls.

Tryptophan kinetic parameters ( Vmax and Km) at low and high concentrations were measured in fibroblasts using the cluster tray method. Uptake of 3H (5)-L-tryptophan at different concentrations in the presence and absence of excess concentrations of inhibitors or combinations of inhibitors of amino acid transporters were also measured. Tryptophan transport at high concentration (0.5 mM) had low affinity and high Vmax and the LAT1 isoform of system-L was responsible for approximately 40% of the total uptake of tryptophan. In comparison, tryptophan transport at low concentration (50 nM) had higher affinity, lower Vmax and approximately 80% of tryptophan uptake was transported by system-L with LAT1 as the major isoform. The uptake of tryptophan at the low concentration was mainly sodium (Na+) dependent, while uptake at high substrate concentration was mainly Na+ independent. A series of different transporter inhibitors had varying inhibitory effects on tryptophan uptake.

This study indicates that tryptophan is transported by multiple transporters that are active at different substrate concentrations in human fibroblast cells. The tryptophan transport trough system-L was mainly facilitated by the LAT1 isoform, at both low and high substrate concentrations of tryptophan.
Mechanisms of long‐term variations in the thermal structure of a warm lake
Authors: Rimmer Alon , Gal Gideon , Opher Tamar , Lechinsky Yury , Yacobi Yosef Z.
Published: April 2011

Analysis of a 39‐yr record (1969–2008) of temperature profiles from Lake Kinneret, Israel, revealed that average epilimnion thickness decreased by ∼ 1.2 m (∼ 3 cm yr−1), metalimnion thickness decreased by between ∼ 1.0 m (December) and ∼ 2.0 m (April), and average temperature of the epilimnion increased by ∼ 1°C (∼ 0.028°C yr−1). Average hypolimnetic temperature remained constant (∼ 15°C), so that the thermal gradient across the metalimnion increased. The average duration of the stratification period (∼ 286 d) remained unchanged. We show that the stratification changes were the result of a decrease in lake level, a slight increase in air temperature during the spring and summer, and a reduction of inflows to the lake. These changes in time affected the stratification pattern in the same direction, i.e., an increase in the lake epilimnetic temperature and an increase in the thermal gradient across the metalimnion. Analysis of the data indicates that the effect of overpumping, which leads to a reduction in lake level, is larger than the effect of changes due to air‐temperature increase and the reduction in inflow volumes.
Importance of N2 fixation vs. nitrate eddy diffusion along a latitudinal transect in the Atlantic Ocean
Authors: Mouriño-Carballido Beatriz , Graña Rocío , Fernàndez Ana , Bode Antonio , Varela Manuel , Domínguez J. Francisco , Escànez José , de Armas Demetrio , Marañón Emilio
Published: April 2011

We present ocean, basin‐scale simultaneous measurements of N2‐fixation, nitrate diffusion, and primary production along a south–north transect in the Atlantic Ocean crossing three biogeographic provinces: the south subtropical Atlantic (SSA; ∼ 31°S–12°S), the equatorial Atlantic (EA; ∼ 12°S–16°N), and the north subtropical Atlantic (NSA, ∼ 16°N–9°N) in April–May 2008. N2‐fixation and primary production were measured as 15N2 and 14C uptake, respectively. Dissipation rates of turbulent kinetic energy (ε) were measured with a microstructure profiler. The vertical input of nitrate through eddy diffusion was calculated from the product of diffusivity, derived from ε, and the gradient of nanomolar nitrate concentration across the base of the euphotic zone. The mean N2‐fixation rate in EA was 56 ± 49 μmol N m−2 d−1, whereas SSA and NSA had much lower values (∼ 10 μmol N m−2 d−1). Because of the large spatial variability in nitrate diffusion (34 ± 50, 405 ± 888, and 844 ± 1258 μmol N m−2 d−1 in SSA, EA, and NSA, respectively), the contribution of N2‐fixation to new production in the SSA, EA, and NSA was 44% ± 30%, 22% ± 19%, and 2% ± 2%, respectively. The differences between SSA and NSA in the contribution of N2 fixation were partly due to the contrasting seasonal forcing in each hemisphere, which likely affected both N2 fixation rates and vertical nitrate diffusion. The variability in the nitrogen budget of the Atlantic subtropical gyres was unexpectedly high and largely uncoupled from relatively constant phytoplankton standing stocks and primary production rates.
The effect of vitamin B12 on phytoplankton growth and community structure in the Gulf of Alaska
Authors: Koch Florian , Marcoval Maria Alejandra , Panzeca Caterina , Bruland Kenneth W. , Sañudo-Wilhelmy Sergio A. , Gobler Christopher J.
Published: April 2011

A majority of eukaryotic phytoplankton species require an exogenous source of vitamin B12 for growth and recent field studies in some coastal and polar regions indicate that the addition of vitamin B12 alone, or with another limiting nutrient can influence the accumulation of phytoplankton biomass. We quantified the concentrations and uptake rates of vitamin B12, characterized phytoplankton community composition, and examined the ability of vitamin B12 to alter the growth and composition of phytoplankton communities in the Gulf of Alaska. Picoplankton (0.2–2 μm) were responsible for the majority of vitamin B12 uptake in both coastal and high‐nutrient low‐chlorophyll (HNLC) regions and B12 concentrations and uptake rates were higher in HNLC regions compared to coastal regions with higher iron (Fe) concentrations. During vitamin amendment experiments, B12 alone or in conjunction with other limiting nutrients (N or Fe) significantly enhanced algal biomass and increased the growth rates of multiple groups of larger (> 2 μm) phytoplankton. This included ecologically significant, B12 auxotrophs such as Gymnodinium sp. and Alexandrium sp. (in the costal experiment) as well as Chaetoceros sp. and Gymnodinium sp. (in the HNLC experiment). The ability of vitamin B12 to shape algal community composition in coastal and HNLC areas of the Gulf of Alaska, even in cases where it does not limit total phytoplankton production, suggests that it may influence carbon export in this and other polar ecosystems.
Biofilm recovery in a wastewater treatment plant‐influenced stream and spatial segregation of ammonia‐oxidizing microbial populations
Authors: Merbt Stephanie N. , Auguet Jean-Christophe , Casamayor Emilio O. , Marti Eugènia
Published: April 2011

We monitored the effects of wastewater treatment plant (WWTP) inputs on the recovery of stream biofilms after a large flood event that eroded most of the former biofilm communities. We monitored biomass recovery, chlorophyll a, nitrogen content, and stable isotope natural abundance (15N) over 8 weeks in light‐ and dark‐exposed biofilms upstream and downstream from WWTP inputs, respectively, as well as the abundance of ammonia oxidizers by quantitative polymerase chain reaction. Biomass and chlorophyll a recovered quickly (< 2 weeks), and were significantly higher for light‐ than for dark‐exposed biofilms. There was no consistent effect of WWTP inputs on these parameters, except for the biomass on dark‐exposed biofilm that was higher at the WWTP‐influenced sites. The influence of the WWTP inputs on stream‐water ammonium concentration and its isotopic 15N signature increased as the flood receded. Biofilm 15N downstream of WWTP increased over time, tracking the increase in 15N‐ammonium from the WWTP waters. Bacterial and archaeal ammonia oxidizers were present within the biofilm assemblages from early stages of postflood recovery. However, spatial distribution of these two clades was clearly segregated among sites and between light‐ and dark‐exposed biofilms, probably related to ammonium availability and the development of photoautotrophic organisms.
Long‐term pigment dynamics and diatom survival in dark sediment
Authors: Veuger Bart , van Oevelen Dick
Published: April 2011

In order to investigate survival of diatoms and long‐term pigment dynamics in dark sediment, we incubated samples of homogenized, sieved, tidal‐flat sediment for 1 yr in darkness. Microscopic observations revealed that some diatoms survived the full year in darkness and retained their pigments. Concentrations of the diatom‐specific phospholipid‐derived fatty acid (PLFA) 20:5ω3 indicate that these survivors represented only a small fraction of the original diatom community, probably no more than a few percent. Consequently, the effect of pigment retention in living diatoms on the overall pigment dynamics was negligible. The photosynthetic potential of the surviving diatoms was further investigated by re‐exposing the sediment to light in the presence of 13C‐bicarbonate. Rapid 13C fixation into algal PLFAs at a level similar to that in sediment freshly collected from the field indicates that surviving diatoms fully retained their photosynthetic capacity. Concentration dynamics of photosynthetic pigments generally reflected degradation of two different pools with clearly different loss rates. Losses during the first 1–2 months of the experiment (half lives of 6–22 d) reflected degradation of fresh algal material, while losses during the rest of the experiment reflected much slower degradation of more refractory pigment pools (half lives of ≥ 1 yr). Individual pigments showed distinctly different labilities, with losses ranging from 0% to 86% over the full year. The order of overall loss was fucoxanthin > chlorophyll c > chlorophyll a > diadinoxanthin > pheophorbide > pheophytin > diatoxanthin.
Phosphorus composition of sinking particles in the Guaymas Basin, Gulf of California
Authors: Lyons Gabrielle , Benitez-Nelson Claudia R. , Thunell Robert C.
Published: April 2011

Phosphorus (P) composition and fluxes were measured in samples collected using a moored sediment trap located at 500 m in depth in the center of Guaymas Basin, Gulf of California, from February 1991 through September 1997. P composition was measured using a sequential extraction technique that chemically separates the particulate inorganic P (PIP) pool into exchangeable, oxide‐bound, authigenic, and detrital phases. PIP comprised 69% ± 15% of the total particulate P pool, with significantly higher concentrations during the rainy summer. Strong relationships between authigenic and detrital P fluxes with lithogenic material (r2 ≥ 0.85) indicate that a significant component of PIP is terrestrially derived and varies with large‐scale changes in regional climate. Particulate organic P (POP) fluxes were significantly higher during the winter as a result of stimulation of biological production during upwelling. Average particulate organic carbon (POC) : POP ratios also varied seasonally, with higher ratios in the summer (221) vs. the winter (158). The fact that POC fluxes remained relatively constant throughout the year indicates that in winter, fresher, less degraded organic material was more effectively transported to depth. Strong correlations between POP and opal fluxes (r2 = 0.63) further support a ballast mechanism, whereby enhanced sinking rates reduce the time during which organic matter is subjected to water column degradation. Compared to trap concentrations, POP is preferentially remineralized over PIP, in concert with an increase in the authigenic P pool; this signifies rapid diagenetic transformations of sedimentary P between the sediment trap and underlying sediments.
Spatial and temporal variability in the ratio of trace gases emitted from biomass burning
Authors: van Leeuwen T. T. , van der Werf G. R.
Published: April 2011

Abstract. Fires are a major source of trace gases and aerosols to the atmosphere. The amount of biomass burned is becoming better known, most importantly due to improved burned area datasets and a better representation of fuel consumption. The spatial and temporal variability in the partitioning of biomass burned into emitted trace gases and aerosols, however, has received relatively little attention. To convert estimates of biomass burned to trace gas and aerosol emissions, most studies have used emission ratios (or emission factors (EFs)) based on the arithmetic mean of field measurement outcomes, stratified by biome. However, EFs vary substantially in time and space, even within a single biome. In addition, it is unknown whether the available field measurement locations provide a representative sample for the various biomes. Here we used the available body of EF literature in combination with satellite-derived information on vegetation characteristics and climatic conditions to better understand the spatio-temporal variability in EFs. While focusing on CO, CH4, and CO2, our findings are also applicable to other trace gases and aerosols. We explored relations between EFs and different measurements of environmental variables that may correlate with part of the variability in EFs (tree cover density, vegetation greenness, temperature, precipitation, and the length of the dry season). Although reasonable correlations were found for specific case studies, correlations based on the full suite of available measurements were lower and explained about 33%, 38%, 19%, and 34% of the variability for respectively CO, CH4, CO2, and the Modified Combustion Efficiency (MCE). This may be partly due to uncertainties in the environmental variables, differences in measurement techniques for EFs, assumptions on the ratio between flaming and smoldering combustion, and incomplete information on the location and timing of EF measurements. We derived new mean EFs, using the relative importance of each measurement location with regard to fire emissions. These weighted averages were relatively similar to the arithmetic mean. When using relations between the environmental variables and EFs to extrapolate to regional and global scales, we found substantial differences, with for savannas 13% and 22% higher CO and CH4 EFs than the arithmetic mean of the field studies, possibly linked to an underrepresentation of woodland fires in EF measurement locations. We argue that from a global modeling perspective, future measurement campaigns could be more beneficial if measurements are made over the full fire season, and if relations between ambient conditions and EFs receive more attention.
Episodes of cross-polar transport in the Arctic troposphere during July 2008 as seen from models, satellite, and aircraft observations
Authors: Sodemann H. , Pommier M. , Arnold S. R. , Monks S. A. , Stebel K. , Burkhart J. F. , Hair J. W. , Diskin G. S. , Clerbaux C. , Coheur P.-F. , Hurtmans D. , Schlager H. , Blechschmidt A.-M. , Kristjánsson J. E. , Stohl A.
Published: April 2011

Abstract. During the POLARCAT summer campaign in 2008, two episodes (2–5 July and 7–10 July 2008) occurred where low-pressure systems traveled from Siberia across the Arctic Ocean towards the North Pole. The two cyclones had extensive smoke plumes from Siberian forest fires and anthropogenic sources in East Asia embedded in their associated air masses, creating an excellent opportunity to use satellite and aircraft observations to validate the performance of atmospheric transport models in the Arctic, which is a challenging model domain due to numerical and other complications. Here we compare transport simulations of carbon monoxide (CO) from the Lagrangian transport model FLEXPART and the Eulerian chemical transport model TOMCAT with retrievals of total column CO from the IASI passive infrared sensor onboard the MetOp-A satellite. The main aspect of the comparison is how realistic horizontal and vertical structures are represented in the model simulations. Analysis of CALIPSO lidar curtains and in situ aircraft measurements provide further independent reference points to assess how reliable the model simulations are and what the main limitations are. The horizontal structure of mid-latitude pollution plumes agrees well between the IASI total column CO and the model simulations. However, finer-scale structures are too quickly diffused in the Eulerian model. Applying the IASI averaging kernels to the model data is essential for a meaningful comparison. Using aircraft data as a reference suggests that the satellite data are biased high, while TOMCAT is biased low. FLEXPART fits the aircraft data rather well, but due to added background concentrations the simulation is not independent from observations. The multi-data, multi-model approach allows separating the influences of meteorological fields, model realisation, and grid type on the plume structure. In addition to the very good agreement between simulated and observed total column CO fields, the results also highlight the difficulty to identify a data set that most realistically represents the actual pollution state of the Arctic atmosphere.
Simulation of the diurnal variations of the oxygen isotope anomaly (Δ17O) of reactive atmospheric species
Authors: Morin S. , Sander R. , Savarino J.
Published: April 2011

Abstract. The isotope anomaly (Δ17O) of secondary atmospheric species such as nitrate (NO3−) or hydrogen peroxide (H2O2) has potential to provide useful constrains on their formation pathways. Indeed, the Δ17O of their precursors (NOx, HOx etc.) differs and depends on their interactions with ozone, which is the main source of non-zero Δ17O in the atmosphere. Interpreting variations of Δ17O in secondary species requires an in-depth understanding of the Δ17O of their precursors taking into account non-linear chemical regimes operating under various environmental settings. This article reviews and illustrates a series of basic concepts relevant to the propagation of the Δ17O of ozone to other reactive or secondary atmospheric species within a photochemical box model. We present results from numerical simulations carried out using the atmospheric chemistry box model CAABA/MECCA to explicitly compute the diurnal variations of the isotope anomaly of short-lived species such as NOx and HOx. Using a simplified but realistic tropospheric gas-phase chemistry mechanism, Δ17O was propagated from ozone to other species (NO, NO2, OH, HO2, RO2, NO3, N2O5, HONO, HNO3, HNO4, H2O2) according to the mass-balance equations, through the implementation of various sets of hypotheses pertaining to the transfer of Δ17O during chemical reactions. The model results confirm that diurnal variations in Δ17O of NOx predicted by the photochemical steady-state relationship during the day match those from the explicit treatment, but not at night. Indeed, the Δ17O of NOx is "frozen" at night as soon as the photolytical lifetime of NOx drops below ca. 10 min. We introduce and quantify the diurnally-integrated isotopic signature (DIIS) of sources of atmospheric nitrate and H2O2, which is of particular relevance to larger-scale simulations of Δ17O where high computational costs cannot be afforded.
The isotopic composition of methane in the stratosphere: high-altitude balloon sample measurements
Authors: Röckmann T. , Brass M. , Borchers R. , Engel A.
Published: April 2011

Abstract. The isotopic composition of stratospheric methane has been determined on a large suite of air samples from stratospheric balloon flights covering subtropical to polar latitudes and a time period of 16 yr. 154 samples were analyzed for δ
Satellite- and ground-based CO total column observations over 2010 Russian fires: accuracy of top-down estimates based on thermal IR satellite data.
Authors: Yurganov L. , Rakitin V. , Dzhola A. , August T. , Fokeeva E. , Gorchakov G. , Grechko E. , Hannon S. , Karpov A. , Ott L. , Semutnikova E. , Shumsky R. , Strow L.
Published: April 2011

Abstract. Data are presented from three space sounders and two ground-based spectrometers in Moscow and its suburbs during the forest and peat fires that occurred in Central Russia in July–August 2010. The Moscow area was strongly impacted by the CO plume from these fires. Concurrent satellite- and ground-based observations were used to quantify the errors of CO top-down emission estimates. On certain days, CO total columns retrieved from the data of the space-based sounders were 2–3 times less than those obtained from the ground-based sun-tracking spectrometers. The depth of the polluted layer over Moscow was estimated using total column measurements compared with CO volume mixing ratios in the surface layer and on the TV tower and found to be between 180 and 360 m. The missing CO that is the average difference between the CO total column accurately determined by the ground spectrometer and that retrieved by MOPITT and AIRS, was determined for the Moscow area as ∼3 E18 molec cm−2. This value was extrapolated onto the entire plume; subsequently, the CO burden (total mass) over Russia during the fire event was corrected. A top-down estimate of the total emitted CO, obtained by a simple mass balance model increased by 80%–100% due to this correction (up to 40 Tg).
Large Asian dust layers continuously reached North America in April 2010
Authors: Uno I. , Eguchi K. , Yumimoto K. , Liu Z. , Hara Y. , Sugimoto N. , Shimizu A. , Takemura T.
Published: April 2011

Abstract. The NASA space-borne Mie-lidar system CALIPSO/CALIOP revealed that multiple large Asian dust layers with a horizontal scale of 2000–3000 km reached North America, occupying the full troposphere, in April 2010. This kind of dust layer transport has not been reported before. Our analysis of CALIOP data and global aerosol model results revealed that frequent dust emissions occurred in northwestern China because of stronger-than-average near-surface winds, and that strong stable westerly winds carried the Asian dust from northwestern China to the central Pacific Ocean. A negative pressure anomaly was located in the eastern Pacific Ocean, and the main dust transport path was split into two branches: a northern path and a southern path over North America. Northern-path dust was trapped and stagnant for a longer time than southern path dust and finally subsided under a high pressure system. Dust along the southern path reached the central US. These complex conditions resulted in a multi-layered structure of dust over North America.
A study of uncertainties in the sulfate distribution and its radiative forcing associated with sulfur chemistry in a global aerosol model
Authors: Goto D. , Nakajima T. , Takemura T. , Sudo K.
Published: April 2011

Abstract. The direct radiative forcing by sulfate aerosols is still uncertain, mainly because the uncertainties are largely derived from differences in sulfate column burdens and its vertical distributions among global aerosol models. One of possible reasons of the large difference in the computed values is that the radiative forcing delicately depends on various simplifications of the sulfur processes made in the models. In this study, therefore, we investigated impacts of different parts of the sulfur chemistry module in a global aerosol model, SPRINTARS, on the sulfate distribution and its radiative forcing. Important studies were effects of simplified and more physical-based sulfur processes in terms of treatment of sulfur chemistry, oxidant chemistry, and dry deposition process of sulfur components. The results showed that the difference in the aqueous-phase sulfur chemistry among these treatments has the largest impact on the sulfate distribution. Introduction of all the improvements mentioned above brought the model values noticeably closer to in-situ measurements than those in the simplified methods used in the original SPRINTARS model. At the same time, these improvements also led the computed sulfate column burdens and its vertical distributions in good agreement with other AEROCOM model values. The global annual mean radiative forcings due to aerosol direct effect of anthropogenic sulfate was thus estimated to be −0.3 W m−2, whereas the original SPRINTARS model showed −0.2 W m−2. The magnitude of the difference between original and improved methods was approximately 50% of the uncertainty among estimates by the world's global aerosol models reported by the IPCC-AR4 assessment report. Findings in the present study, therefore, may suggest that the model differences in the simplifications of the sulfur processes are still a part of the large uncertainty in their simulated radiative forcings.
Spatial variation of chemical composition and sources of submicron aerosol in Zurich: factor analysis of mobile aerosol mass spectrometer data
Authors: Mohr C. , Richter R. , DeCarlo P. F. , Prévôt A. S. H. , Baltensperger U.
Published: April 2011

Abstract. Mobile measurements of PM1 (PM with an aerodynamic diameter D<1 μm) chemical composition using a quadrupole aerosol mass spectrometer and a multi-angle absorption photometer were performed using the PSI mobile laboratory during winter 2007/2008 and December 2008 in the metropolitan area of Zurich, Switzerland. Positive matrix factorization (PMF) applied to the organic fraction of PM1 yielded 3 factors: Hydrocarbon-like organic aerosol (HOA) related to traffic emissions; organic aerosol from wood burning for domestic heating purposes (WBOA); and oxygenated organic aerosol (OOA), assigned to secondary organic aerosol formed by oxidation of volatile precursors. The spatial variation of the chemical composition of PM1 shows a uniform distribution throughout the city: for primary emissions, road traffic is important along major roads (varying between 7 and 14% of PM1 for different sites within the city), but overall, domestic wood burning is more important for the organic aerosol concentrations in Zurich during winter time (varying between 8–15% of PM1 for different sites within the city). OOA makes up the largest fraction of organic aerosol (44% on average). A new method, based on simultaneous on-road mobile and stationary background measurements and using the ratio of on-road sulfate to stationary sulfate to correct for small-scale dynamic effects, allows for the separation of PM1 emitted or produced locally and the PM1 from the regional background. It could be shown that especially during thermal inversions over the Swiss plateau, regional background concentrations contribute substantially to particulate number concentrations (60% on average) as well as to the concentrations of PM1 components (on average 60% for black carbon and HOA, over 97% for WBOA and OOA, and more than 94% for the measured inorganic components) in downtown Zurich. The results emphasize, on a scientific level, the advantage of mobile measurements for distinguishing local from regional air pollution, and on a political level, the importance of regional collaboration for mitigating air pollution issues.
Large-eddy simulation of plume dispersion within regular arrays of cubic buildings
Authors: Nakayama H. , Jurcakova K. , Nagai H.
Published: April 2011

Abstract. There is a potential problem that hazardous and flammable materials are accidentally or intentionally released within populated urban areas. For the assessment of human health hazard from toxic substances, the existence of high concentration peaks in a plume should be considered. For the safety analysis of flammable gas, certain critical threshold levels should be evaluated. Therefore, in such a situation, not only average levels but also instantaneous magnitudes of concentration should be accurately predicted. In this study, we perform Large-Eddy Simulation (LES) of plume dispersion within regular arrays of cubic buildings with large obstacle densities and investigate the influence of the building arrangement on the characteristics of mean and fluctuating concentrations.
Amplification and dampening of soil respiration by changes in temperature variability
Authors: Sierra C. A. , Harmon M. E. , Thomann E. , Perakis S. S. , Loescher H. W.
Published: April 2011

Abstract. Accelerated release of carbon from soils is one of the most important feedbacks related to anthropogenically induced climate change. Studies addressing the mechanisms for soil carbon release through organic matter decomposition have focused on the effect of changes in the average temperature, with little attention to changes in temperature variability. Anthropogenic activities are likely to modify both the average state and the variability of the climatic system; therefore, the effects of future warming on decomposition should not only focus on trends in the average temperature, but also variability expressed as a change of the probability distribution of temperature. Using analytical and numerical analyses we tested common relationships between temperature and respiration and found that the variability of temperature plays an important role determining respiration rates of soil organic matter. Changes in temperature variability, without changes in the average temperature, can affect the amount of carbon released through respiration over the long-term. Furthermore, simultaneous changes in the average and variance of temperature can either amplify or dampen the release of carbon through soil respiration as climate regimes change. These effects depend on the degree of convexity of the relationship between temperature and respiration and the magnitude of the change in temperature variance. A potential consequence of this effect of variability would be higher respiration in regions where both the mean and variance of temperature are expected to increase, such as in some low latitude regions; and lower amounts of respiration where the average temperature is expected to increase and the variance to decrease, such as in northern high latitudes.
Ecosystem metabolism in a temporary Mediterranean marsh (Doñana National Park, SW Spain)
Authors: Geertz-Hansen O. , Montes C. , Duarte C. M. , Sand-Jensen K. , Marbá N. , Grillas P.
Published: April 2011

Abstract. The metabolic balance of the open waters supporting submerged macrophytes of the Doñana marsh (SW Spain) was investigated in spring, when community production is highest. The marsh community (benthic + pelagic) was net autotrophic with net community production rates averaging 0.61 g C m−2 d−1, and gross production rates exceeding community respiration rates by, on average, 43%. Net community production increased greatly with increasing irradiance, with the threshold irradiance for communities to become net autotrophic ranging from 42 to 255 μE m−2 s−1, with net heterotrophic at lower irradiance. Examination of the contributions of the benthic and the pelagic compartments showed the pelagic compartment to be strongly heterotrophic (average P/R ratio = 0.27), indicating that the metabolism of the pelagic compartment is highly subsidised by excess organic carbon produced in the strongly autotrophic benthic compartment (average P/R = 1.58).
Effectiveness of a Protocol for the Prevention of Hemodialysis Venous Catheter-Related Infections
Authors: Cornacchiari Marina , Heidempergher Marco , Stasi Antonia , Baroli Ambrogio , Bertoncini Lucio , Turri Corrado , Bellotti Nicoletta , Guastoni Carlo
Published: April 2011

Purpose

Infections are a major complication of the use of hemodialysis central venous catheters. In our study we evaluated the efficacy of the hemodialysis central venous catheter protocol management adopted in our center, through a retrospective analysis of all hemodialysis central venous catheters inserted over a period of 6 years.

Methods

Seventy-three tunneled central venous catheters and 75 temporary central venous catheters were inserted in our center from 2003 to 2008 in 148 patients.

Results

During the follow-up we observed 30 infective events (16 assessed as bacteremias, 14 subcutaneous tunnel or exit site infections) with a rate of 0.65/1,000 days of central venous catheter implantation.

Conclusions

Our experience confirms, in a 72-month follow-up, the importance of careful central venous catheter management as a crucial feature in reducing the incidence of infective events in patients with central venous catheters in dialytic treatment.
Mule Bite to the Male Genitalia with Complete Penile and Anterior Urethra Amputation: Unusual Case and Review of the Literature
Authors: Lakmichi M. A. , Wakrim B. , Jarir R. , Dahami Z. , Moudouni M. S. , Sarf I.
Published: April 2011

Animal bite is rare with few cases reported in the literature. The morbidity of animal bites is directly related to the severity of the initial wound. Most victims are boys, and dog bites are the most common injury. Infectious complications are unusual, since treatment is sought early (Wein 2007). Thus, urologists are not usually familiar with management and principles for treating this condition. The authors report the case of a 38-year-old male with a severe mule bite injury to the genitalia causing complete penile and anterior urethra amputation and scrotal wound with no involvement of its contents. To our knowledge, no such case had ever been reported in the medical literature. This kind of emergencies is challenging for urologists.