bluuebunny/crossref_metadata_2025 huggingface dataset:
Desert Bighorn Sheep: Changes in Genetic Variation Over Time and the Impact of Merging Populations
Authors: Hedrick Philip W. , Wehausen John D.
Published: February 2014

Founder effects, genetic bottlenecks, and genetic drift in general can lead to low levels of genetic diversity, which can influence the persistence of populations. We examine genetic variation in two populations of desert bighorn sheep Ovis canadensis from New Mexico and Mexico to measure change over time and evaluate the impact of introducing individuals from one population into the other. Over about three generations, the amount of genetic variation in the New Mexico population increased. In contrast, over about two generations the amount of genetic variation in the Mexican population decreased by a great extent compared with an estimate from another Mexican population from which it is primarily descended. The potential reasons for these changes are discussed. In addition, although both populations have low genetic variation, introduction of Mexican rams into the New Mexico population might increase the amount of genetic variation in the New Mexico population. Overall, it appears that management to increase genetic variation might require substantial detailed monitoring and evaluation of ancestry from the different sources and fitness components.
Regulation of Spontaneous Eosinophil Apoptosis—A Neglected Area of Importance
Authors: Ilmarinen Pinja , Moilanen Eeva , Kankaanranta Hannu
Published: February 2014

Asthma is characterized by the accumulation of eosinophils in the airways in most phenotypes. Eosinophils are inflammatory cells that require an external survival-prolonging stimulus such as granulocyte macrophage-colony-stimulating factor (GM-CSF), interleukin (IL)-5, or IL-3 for survival. In their absence, eosinophils are programmed to die by spontaneous apoptosis in a few days. Eosinophil apoptosis can be accelerated by Fas ligation or by pharmacological agents such as glucocorticoids. Evidence exists for the relevance of these survival-prolonging and pro-apoptotic agents in the regulation of eosinophilic inflammation in inflamed airways. Much less is known about the physiological significance and mechanisms of spontaneous eosinophil apoptosis even though it forms the basis of regulation of eosinophil longevity by pathophysiological factors and pharmacological agents. This review concentrates on discussing the mechanisms of spontaneous eosinophil apoptosis compared to those of glucocorticoid- and Fas-induced apoptosis. We aim to answer the question whether the external apoptotic stimuli only augment the ongoing pathway of spontaneous apoptosis or truly activate a specific pathway.
Stem Cells: The Future of Personalised Medicine?
Authors: Irfan Ahmer , Ahmed Irfan
Published: February 2014

After hitting the headlines in the 1960s, stem cell therapy has been the subject of great optimism in the treatment of many conditions. Discoveries of new procurement methods for various stem cells has allowed the technology and research to progress to a stage where real therapeutic alternatives are potentially viable.

In order to determine the direction to move forward, it is first important to analyse the data that has been collected across well researched stem cell types (Embryonic Stem cells, Induced pluripotent stem cells, Haematopoetic stem cells and Mesenchymal stem cells) as well as emerging stem cell types (Very-small-embryonic-like stem cells, Spermatogonial stem cells and Parthenogenetic stem cells).

Whilst by no means conclusive, the data does support the optimism surrounding these cells. Whilst stem cells may be embraced as the future of personalised medicine, following these pilot trials, research needs to become more focussed to allow advancement.
Substance Misuse in the Psychiatric Emergency Service; A Descriptive Study
Authors: Chaput Yves , Lebel Marie-Josέe , Beaulieu Lucie , Paradis Michel , Labonté Edith
Published: February 2014

Substance misuse is frequently encountered in the psychiatric emergency service (PES) and may take many forms, ranging from formal DSM-IV diagnoses to less obvious entities such as hazardous consumption. Detecting such patients using traditional screening instruments has proved problematic. We therefore undertook this study to more fully characterize substance misuse in the PES and to determine whether certain variables might help better screen these patients. We used a prospectively acquired database of over 18,000 visits made to four PESs during a 2-year period in the province of Quebec, Canada. One of the variables acquired was a subjective rating by the nursing staff as to whether substance misuse was a contributing factor to the visit (graded as direct, indirect, or not at all). Substance misuse accounted for 21% of all diagnoses and alcohol was the most frequent substance used. Patients were divided into those with primary (PSM), comorbid (CSM) or no substance misuse (NSM). Depressive disorders were the most frequent primary diagnoses in CSM, whereas personality and substance misuse disorders were frequent secondary diagnoses in PSM. Although many variables significantly differentiated the three groups, few were sufficiently detailed to be used as potential screening tools. Those situations that did have sufficient details included those with a previous history of substance misuse, substance misuse within 48 hours of the visit, and visits graded by the nursing staff as being directly and/or indirectly related to substance misuse. Variables related to substance misuse itself were the primary predictors of PSM and, less significantly, CSM. The nursing staff rating, although promising, was obtained in less than 30% of all visits, rendering its practical use difficult to assess.
Psychosocial and Behavioral Characteristics among Subgroups of Nondaily College Student Smokers
Authors: Romero Devan R. , Pulvers Kim , Scheuermann Taneisha S. , Ahluwalia Jasjit S.
Published: February 2014

Nondaily smoking is becoming common in young adults and there appear to be different characteristics associated with past month smoking frequency among nondaily smokers. The present study examines behavioral and psychosocial correlates of smoking among subgroups of nondaily college student smokers ( N = 80; 18–25 years of age) attending a large, public university. Nondaily smokers were categorized based on the frequency of days smoked in the past month and were divided into two subgroups: 1–5 days and 6–29 days. A quarter of nondaily smokers considered themselves as a smoker and significantly more 6–29 nondaily smokers were identified as a smoker and smoked more cigarettes per day (CPD). Almost half (45%) of nondaily smokers have attempted to quit smoking completely and 71% of the 6–29 nondaily smokers reported significantly higher quit attempts. The 6–29 nondaily smokers had significantly higher perceived risk related to smoking. Self-efficacy to abstain from smoking was significantly higher for 1–5 nondaily smokers. These results suggest heterogeneity among subgroups of nondaily college student smokers exists in a number of behavioral and psychosocial factors. Prevention and cessation strategies may be improved by considering frequency of nondaily smoking and targeting subgroups differently.
Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR
Authors: Pérot K. , Urban J. , Murtagh D. P.
Published: February 2014

Abstract. The middle atmosphere has been affected by an exceptionally strong midwinter stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These unusual meteorological conditions led to a breakdown of the polar vortex, followed by the reformation of a strong upper stratospheric vortex associated with particularly efficient descent of air. Measurements by the Sub-Millimetre Radiometer (SMR), on board the Odin satellite, show that very large amounts of nitric oxide (NO), produced by Energetic Particle Precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus enter the polar stratosphere in early 2013. The mechanism referring to the downward transport of EPP generated-NOx during winter is generally called the EPP indirect effect. SMR observed up to 20 times more NO in the upper stratosphere than the average NO measured at the same latitude, pressure and time during three previous winters where no mixing between mesospheric and stratospheric air was noticeable. This event turned out to be an unprecedently strong case of this effect. Our study is based on a comparison with the Arctic winter 2008/2009, when a similar situation was observed and which was so far considered as a record-breaking winter for this kind of events. This outstanding situation is the result of the combination between a relatively high geomagnetic activity and an unusually high dynamical activity, which makes this case a prime example to study the EPP impacts on the atmospheric composition.
Functional characterization of the water-soluble organic carbon of size fractionated aerosol in the Southern Mississippi Valley
Authors: Chalbot M.-C. G. , Brown J. , Chitranshi P. , Gamboa da Costa G. , Pollock E. D. , Kavouras I. G.
Published: February 2014

Abstract. The chemical content of the water soluble organic carbon (WSOC) as a function of particle size was characterized in Little Rock, Arkansas in winter and spring 2013. The objectives of this study were to: (i) compare the functional characteristics of coarse, fine and ultrafine WSOC and (ii) reconcile the sources of WSOC for the period when carbonaceous aerosol was the most abundant particulate component. The WSOC accounted for 5% of particle mass for particles with dp > 0.96 μm and 10% of particle mass for particles with dp < 0.96 μm. Non-exchangeable aliphatic (H-C), unsaturated aliphatic (H-C-C=), oxygenated saturated aliphatic (H-C-O), acetalic (O-CH-O) and aromatic (Ar-H) protons were determined by proton nuclear magnetic resonance. The total non-exchangeable organic hydrogen concentrations varied from 4.1 ± 0.1 nmol m−3 for particles with 0.96 < dp < 1.5 μm to 73.9 ± 12.3 nmol m−3 for particles with dp < 0.49 μm, resulting in molar H / C ratios of 0.48 ± 0.05 to 0.92 ± 0.09 observed in combustion-related organic aerosol. The R-H was the most abundant group representing about 45% of measured total non-exchangeable organic hydrogen concentration followed by H-C-O (27%) and H-C-C= (26%). Levoglucosan, amines, ammonium and methanosulfonate were tentatively identified in NMR fingerprints of fine particles. Sucrose, fructose, glucose, formate and acetate were associated with coarse particles. These qualitative differences of 1H-NMR profiles for different particle sizes indicated the possible contribution of biological aerosol and a mixture of aliphatic and oxygenated compounds from biomass burning and traffic exhausts. The concurrent presence of ammonium and amines also suggested the presence of ammonium/aminium nitrate and sulfate secondary aerosol. The size-dependent origin of WSOC was further corroborated by the increasing δ13C abundance from −26.81 ± 0.18‰ for the smallest particles to −25.93 ± 0.31‰ for the largest particles and the relative distribution of the functional groups as compared to those previously observed for marine, biomass burning and secondary organic aerosol. The latter also allowed for the differentiation of urban combustion-related aerosol and biological particles. The five types of organic hydrogen accounted for the majority of WSOC for particles with dp > 3.0 μm and dp < 0.96 μm.
Factors controlling temporal variability of near-ground atmospheric 222Rn concentration over Central Europe
Authors: Zimnoch M. , Wach P. , Chmura L. , Gorczyca Z. , Rozanski K. , Godlowska J. , Mazur J. , Kozak K. , Jeričević A.
Published: February 2014

Abstract. Specific activity of 222Rn in near-ground atmosphere has been measured quasi-continuously from January 2005 to December 2009 at two continental sites in Europe: Heidelberg (south-west Germany) and Krakow (southern Poland). Atmosphere was sampled at ca. 30 m and 20 m, respectively, above the local ground. Both stations were equipped with identical instrumentation. Regular observations of 222Rn were supplemented by measurements of surface fluxes of this gas in Krakow urban area, using two entirely different approaches. Atmospheric 222Rn concentrations varied at both sites in a wide range, from less than 2 Bq m−3 to approximately 40 Bq m−3 in Krakow and ca. 35 Bq m−3 in Heidelberg. Averaged over entire observation period, the 222Rn content in Krakow was approximately 30 % higher when compared to Heidelberg (5.86 ± 0.09 Bq −3 and 4.50 ± 0.07 Bq m−3, respectively). Distinct seasonality of 222Rn signal was visible in both presented time series, with higher values recorded generally during late summer and autumn. The surface 222Rn fluxes in Krakow also revealed a distinct seasonality, with broad maximum observed during summer and early autumn and minimum during the winter. Averaged over 5 yr observation period, the night-time surface 222Rn flux was equal 46.8 ± 2.4 Bq m−2 h−1. Although the atmospheric 222Rn levels at Heidelberg and Krakow appeared to be controlled primarily by local factors, it was possible to evaluate the "continental effect" in atmospheric 222Rn content between both sites, related to the gradual build-up of 222Rn concentration in the air masses travelling between Heidelberg and Krakow. The mean value of this load was equal 0.78 ± 0.12 Bq m−3. The measured minimum 222Rn concentrations at both sites and the difference between them was interpreted in the framework of a simple box model coupled with HYSPLIT analysis of air mass trajectories. Best fit of experimental and model data was obtained for the average 222Rn flux over the European continent equal 52 Bq m−2 h−1, the mean transport velocity of the air masses within convective mixed layer of PBL on their route from the Atlantic coast to Heidelberg and Krakow equal 3.5 m s−1, the mean rate constant of 222Rn removal across the top of PBL equal to the 222Rn decay constant and the mean height of the convective mixed layer height equal 1600 m.
Climatology of aerosol optical properties and black carbon mass absorption cross section at a remote high altitude site in the Western Mediterranean Basin
Authors: Pandolfi M. , Ripoll A. , Querol X. , Alastuey A.
Published: February 2014

Abstract. Aerosol light scattering, backscattering and absorption were measured at Montsec (MSC; 42°3' N, 0°44' E, 1570 m a.s.l.), a remote high-altitude site in the Western Mediterranean Basin. Mean (± sd) scattering, hemispheric backscattering and absorption were 18.9 ± 20.8 Mm−1, 2.6 ± 2.8 Mm−1 and 1.5 ± 1.4 Mm−1, respectively at 635 nm during the period under study (June 2011–June 2013). Mean values of single scattering albedo (635 nm), scattering Ångström exponent (450–635 nm), backscatter-to-scatter ratio (635 nm), asymmetry parameter (635 nm) and black carbon mass absorption cross section (637 nm) were 0.92 ± 0.03, 1.56 ± 0.88, 0.16 ± 0.09, 0.53 ± 0.16 and 10.9 ± 3.5 m2 g−1 respectively. The scattering measurements performed at MSC locate this site in the medium/upper range of values reported for other mountaintop sites in Europe mainly due to the frequent African dust episodes and regional recirculation scenarios occurring mostly in spring/summer and causing the presence of polluted layers at the MSC altitude. Under these conditions no clear diurnal cycles were observed for the measured extensive aerosol optical properties (scattering, absorption and extinction). Conversely, the mean particle absorption at MSC was relatively lower compared with other EU remote stations thus leading to relatively higher single scattering albedo compared with most European data. A season-dependent decrease in the magnitude of aerosol extensive properties was observed when MSC was in the free troposphere with the highest free-troposphere vs. all-data difference observed in winter and the lowest in spring/summer. The slope of the scattering vs. absorption relationship (among the lowest reported for other mountain top sites worldwide) indicates that the MSC site is dominated by dust aerosols at high aerosol loading. Correspondingly, scattering Ångström exponent and asymmetry parameter respectively decreased and increased indicating the shift toward larger particles associated with African dust episodes. The black carbon mass absorption cross section showed a clear annual cycle with higher values in summer when the occurrence of African dust outbreaks and regional recirculation scenarios favour the presence of aged black carbon particles in polluted layers at the MSC altitudes. The optical measurements performed at the MSC remote site were compared with those simultaneously performed at a regional background station in the Western Mediterranean Basin.
A novel gridding algorithm to create regional trace gas maps from satellite observations
Authors: Kuhlmann G. , Hartl A. , Cheung H. M. , Lam Y. F. , Wenig M. O.
Published: February 2014

Abstract. The recent increase in spatial resolution for satellite instruments has made it feasible to study distributions of trace gas column densities on a regional scale. For this application a new gridding algorithm was developed to map measurements from the instrument's frame of reference (level 2) onto a longitude–latitude grid (level 3). The algorithm is designed for the Ozone Monitoring Instrument (OMI) and can easily be employed for similar instruments – for example, the upcoming TROPOspheric Monitoring Instrument (TROPOMI). Trace gas distributions are reconstructed by a continuous parabolic spline surface. The algorithm explicitly considers the spatially varying sensitivity of the sensor resulting from the instrument function. At the swath edge, the inverse problem of computing the spline coefficients is very sensitive to measurement errors and is regularised by a second-order difference matrix. Since this regularisation corresponds to the penalty term for smoothing splines, it similarly attenuates the effect of measurement noise over the entire swath width. Monte Carlo simulations are conducted to study the performance of the algorithm for different distributions of trace gas column densities. The optimal weight of the penalty term is found to be proportional to the measurement uncertainty and the width of the instrument function. A comparison with an established gridding algorithm shows improved performance for small to moderate measurement errors due to better parametrisation of the distribution. The resulting maps are smoother and extreme values are more accurately reconstructed. The performance improvement is further illustrated with high-resolution distributions obtained from a regional chemistry model. The new algorithm is applied to tropospheric NO2 column densities measured by OMI. Examples of regional NO2 maps are shown for densely populated areas in China, Europe and the United States of America. This work demonstrates that the newly developed gridding algorithm improves regional trace gas maps; its application could be very helpful for the study of satellite-derived trace gas distributions.
Retrieval techniques for airborne imaging of methane concentrations using high spatial and moderate spectral resolution: application to AVIRIS
Authors: Thorpe A. K. , Frankenberg C. , Roberts D. A.
Published: February 2014

Abstract. Two quantitative retrieval techniques were evaluated to estimate methane (CH4) enhancement in concentrated plumes using high spatial and moderate spectral resolution data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). An iterative maximum a posteriori differential optical absorption spectroscopy (IMAP-DOAS) algorithm performed well for an ocean scene containing natural CH4 emissions from the Coal Oil Point (COP) seep field near Santa Barbara, California. IMAP-DOAS retrieval precision errors are expected to equal between 0.31 to 0.61 ppm CH4 over the lowest atmospheric layer (height up to 1.04 km), corresponding to about a 30 to 60 ppm error for a 10 m thick plume. However, IMAP-DOAS results for a terrestrial scene were adversely influenced by the underlying land cover. A hybrid approach using singular value decomposition (SVD) was particularly effective for terrestrial surfaces because it could better account for spectral variability in surface reflectance. Using this approach, a CH4 plume was observed extending 0.1 km downwind of two hydrocarbon storage tanks at the Inglewood Oil Field in Los Angeles, California (USA) with a maximum near surface enhancement of 8.45 ppm above background. At COP, the distinct plume had a maximum enhancement of 2.85 ppm CH4 above background, and extended more than 1 km downwind of known seep locations. A sensitivity analysis also indicates CH4 sensitivity should be more than doubled for the next generation AVIRIS sensor (AVIRISng) due to improved spectral resolution and sampling. AVIRIS-like sensors offer the potential to better constrain emissions on local and regional scales, including sources of increasing concern like industrial point source emissions and fugitive CH4 from the oil and gas industry.
Estimation of atmospheric mixing layer height from radiosonde data
Authors: Wang X. Y. , Wang K. C.
Published: February 2014

Abstract. Mixing layer height (h) is an important parameter for understanding the transport process in the troposphere, air pollution, weather and climate change. Many methods have been proposed to determine h by identifying the turning point of the radiosonde profile. However, substantial differences have been observed in the existing methods (e.g., the potential temperature (θ), relative humidity (RH), specific humidity (q) and atmospheric refractivity (N) methods). These differences are associated with the inconsistency of the temperature and humidity profiles in a boundary layer that is not well mixed, the changing measurability of the specific humidity and refractivity with height, the measurement error of humidity instruments within clouds, and the general existence of clouds. This study proposes a method to integrate the information of temperature, humidity and cloud to generate a consistent estimate of h. We apply this method to high vertical resolution (~ 30 m) radiosonde data that were collected at 79 stations over North America during the period from 1998 to 2008; the data are obtained from the Stratospheric Processes and their Role in Climate Data Center (SPARC). The results show good agreement with those from N method as the information of temperature and humidity contained in N; however cloud effects that are included in our method increased the reliability of h. Furthermore, our results agree well with the independent h that was determined from lidar observations. From 1988 to 2008, the climatological h over North America was 1675± 303 m with a strong east–west gradient: higher values (generally greater than 1800 m) occurred over the Midwest US, and lower values (usually less than 1400 m) occurred over Alaska and the US west coast.
Variable anisotropy of small-scale stratospheric irregularities retrieved from stellar scintillation measurements by GOMOS/Envisat
Authors: Kan V. , Sofieva V. F. , Dalaudier F.
Published: February 2014

Abstract. In this paper, we consider possibilities for studying the anisotropy of small-scale air density irregularities using satellite observations of bi-chromatic stellar scintillations during tangential occultations. Estimation of the anisotropy coefficient (the ratio of the characteristic horizontal to vertical scales) and other atmospheric parameters is based on the comparison of simulated/theoretical and experimental auto-spectra and coherency spectra of scintillation. Our analyses exploit a 3-D model of the spectrum of atmospheric inhomogeneities, which consists of anisotropic and isotropic components. For the anisotropic component, a spectral model with variable anisotropy is used. Using stellar scintillation measurements by GOMOS (Global Ozone Monitoring by Occultation of Stars) fast photometers, estimates of the anisotropy coefficient are obtained for atmospheric irregularities with vertical scales of 8–55 m at altitudes of 43–30 km. It is shown that the anisotropy increases from about 10 to 50 with increasing vertical scales.
Study of cloud effect on the tropospheric temperature retrievals
Authors: Navas-Guzmán F. , Stähli O. , Kämpfer N.
Published: February 2014

Abstract. In this paper, we address the characterization of clouds and its inclusion in microwave retrievals in order to study its effect on tropospheric temperature profiles measured by TEMPERA radiometer. TEMPERA is the first ground-based microwave radiometer that allows to obtain temperature profiles in the troposphere and stratosphere at the same time. In order to characterize the clouds a multi-instrumental approach has been performed. Cloud base altitudes were detected using ceilometer measurements while the integrated liquid water was measured by TROWARA radiometer. Both instruments are co-located with TEMPERA in Bern (Switzerland). Using this information and a constant Liquid Water Content value inside the cloud a liquid profile is provided to characterize the clouds in the inversion algorithm. Microwave temperature profiles have been obtained incorporating this water liquid profile in the inversion algorithm and also without considering the clouds, in order to asses its effect on the retrievals. The results have been compared with the temperature profiles from radiosondes which are launched twice a day at the aerological station of MeteoSwiss in Payerne (40 km W of Bern). Almost one year of data has been analyzed and 60 non-precipitating cloud cases were studied. The statistical analysis carried out over all the cases evidenced that temperature retrievals improved in most of the cases when clouds were incorporated in the inversion algorithm.
A stand-alone tree demography and landscape structure module for Earth system models: integration with global forest data
Authors: Haverd V. , Smith B. , Nieradzik L. P. , Briggs P. R.
Published: February 2014

Abstract. Poorly constrained rates of biomass turnover are a key limitation of Earth system models (ESM). In light of this, we recently proposed a new approach encoded in a model called Populations-Order-Physiology (POP), for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity. POP is suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any ESM. POP bridges the gap between first generation Dynamic Vegetation Models (DVMs) with simple large-area parameterisations of woody biomass (typically used in current ESMs) and complex second generation DVMs, that explicitly simulate demographic processes and landscape heterogeneity of forests. The key simplification in the POP approach, compared with second-generation DVMs, is to compute physiological processes such as assimilation at grid-scale (with CABLE or a similar land surface model), but to partition the grid-scale biomass increment among age classes defined at sub grid-scale, each subject to its own dynamics. POP was successfully demonstrated along a savanna transect in northern Australia, replicating the effects of strong rainfall and fire disturbance gradients on observed stand productivity and structure. Here, we extend the application of POP to a range of forest types around the globe, employing paired observations of stem biomass and density from forest inventory data to calibrate model parameters governing stand demography and biomass evolution. The calibrated POP model is then coupled to the CABLE land surface model and the combined model (CABLE-POP) is evaluated against leaf-stem allometry observations from forest stands ranging in age from 3 to 200 yr. Results indicate that simulated biomass pools conform well with observed allometry. We conclude that POP represents a preferable alternative to large-area parameterisations of woody biomass turnover, typically used in current ESMs.
Evaluation of the ECHAM family radiation codes performance in the representation of the solar signal
Authors: Sukhodolov T. , Rozanov E. , Shapiro A. I. , Anet J. , Cagnazzo C. , Peter T. , Schmutz W.
Published: February 2014

Abstract. Solar radiation is the main source of energy for the Earth's atmosphere and in many respects defines its composition, photochemistry, temperature profile and dynamics. The magnitude of the solar irradiance variability strongly depends on the wavelength making difficult its representation in climate models. Due to some deficiencies of the applied radiation codes several models fail to show a clear response in middle stratospheric heating rates to solar spectral irradiance variability, therefore it is important to prove reasonable model performance in this respect before doing multiple model runs. In this work we evaluate the performance of three generations of ECHAM (4, 5 and 6) radiation schemes by comparison with the reference high resolution libRadtran code. We found that both original ECHAM5 and 6 solar radiation codes miss almost all solar signal in the heating rates in the mesosphere. In the stratosphere ECHAM5 code reproduces only about a half of the reference signal, while representation of ECHAM6 code is better – it maximally misses about 17% in the upper stratosphere. On the basis of the comparison results we suggest necessary improvements of the ECHAM family codes by inclusion of available parameterizations of the heating rate due to absorption by oxygen (O2) and ozone (O3). Both codes with the introduced parameterizations represent the heating rate response to the spectral solar irradiance variability simulated with libRadtran much better without substantial increase of computer time. The suggested parameterizations are recommended to apply in the middle atmosphere version of the ECHAM-5 and 6 models for the study of the solar irradiance influence on climate.
Globalization of agricultural pollution due to international trade
Authors: O'Bannon C. , Carr J. , Seekell D. A. , D'Odorico P.
Published: February 2014

Abstract. Almost 90% of freshwater resources consumed globally are used to produce plant and animal commodities. Water-scarce countries can balance their water needs by importing food from other countries. This process, known as virtual water transfer, represents the externalization of water use. The volume and geographic reach of virtual water transfers is increasing, but little is known about how these transfers redistribute the environmental costs of agricultural production. The grey water footprint quantifies the environmental costs of virtual water transfers. The grey water footprint is calculated as the amount of water necessary to reduce nitrogen concentrations from fertilizers and pesticides released into streams and aquifers to allowed standards. We reconstructed the global network of virtual grey water transfers for the period 1986–2010 based on international trade data and grey water footprints for 309 commodities. We tracked changes in the structure of the grey water transfer network with network and inequality statistics. Pollution is increasing and is becoming more strongly concentrated in only a handful of countries. The global external grey water footprint, the pollution created by countries outside of their borders, increased 136% during the period. The extent of externalization of pollution is highly unequal between countries, and most of this inequality is due to differences in social development status. Our results demonstrate a growing globalization of pollution due to virtual water transfers.
Contribution of snow and glacier melt to discharge for highly glacierised catchments in Norway
Authors: Engelhardt M. , Schuler T. V. , Andreassen L. M.
Published: February 2014

Abstract. Glacierised catchments show a discharge regime that is strongly influenced by snow and glacier meltwaters. In this study, we modelled the mass balance and discharge rates for three highly glacierised catchments (>50% glacier cover) in western Norway over the period 1961–2012. The spatial pattern of the catchments follows a gradient in climate continentality from west to east. The model input were gridded temperature and precipitation values from seNorge (http://senorge.no) which are available at daily resolution. The model accounted for accumulation of snow, transformation of snow to firn and ice, evaporation and melt. Calibration and validation were performed for each catchment based on measurements of seasonal glacier mass balances and daily discharge rates, as additional validation data served daily melt rates from sonic rangers located in the ablation zones of two of the glaciers. The discharge sources snowmelt, glacier melt and rain were analysed with respect to spatial variations and temporal evolution. Model simulations reveal an increase in the relative contribution from glacier melt to total discharge for the three catchments from less than 10% in the early 1990s to 15–30% in the late 2000s. The decline in precipitation by 10–20% in the same period was therefore overcompensated, resulting in an increase in annual discharge by 5–20%. Annual discharge sums and annual glacier melt are most strongly correlated with annual and winter precipitation at the most maritime glacier and, with increased climate continentality, variations in both glacier melt contribution and annual discharge are becoming more strongly correlated with variations in summer temperatures. Therefore, glaciers in more continental climates are especially vulnerable to decrease in both annual and summer discharge with continued rise in summer temperatures and subsequent decrease in glacier extent. This may lead to significant changes to the discharge regime, with increase during spring but decline later in the year, especially for catchments in less maritime climate conditions.
A 2-D hydro-morphodynamic modelling approach for predicting suspended sediment propagation and related heavy metal contamination in floodplain: a sensitivity analysis
Authors: Hostache R. , Hissler C. , Matgen P. , Guignard C. , Bates P.
Published: February 2014

Abstract. Fine sediments represent an important vector of pollutant diffusion in rivers. When deposited in floodplains and riverbeds they can be responsible for soil pollution. In this context, this paper proposes a hydro-morphodynamic modelling exercise aiming at predicting transport and diffusion of fine sediments and dissolved pollutants. The model is based upon the Telemac hydro-informatic system (dynamical coupling Telemac-2D-Sysiphe). As empirical and semi-empirical parameters need to be calibrated for such a modelling exercise, a sensitivity analysis is proposed. In parallel to the modelling exercise, an extensive hydrological/geochemical database has been set up during two flood events. The main sensitive parameters were found to be the hydraulic friction coefficient and the sediment particle settling velocity in water. Using the two monitored hydrological events as calibration and validation, it was found that the model is able to satisfyingly predict suspended sediment and dissolve pollutant transport in the river channel. In addition, a qualitative comparison between simulated sediment deposition in the floodplain and a soil contamination map shows that the preferential zones for deposition identified by the model are realistic.
Stochastic daily precipitation model with a heavy-tailed component
Authors: Neykov N. M. , Neytchev P. N. , Zucchini W.
Published: February 2014

Abstract. Stochastic daily precipitation models are commonly used to generate scenarios of climate variability or change on a daily time scale. The standard models consist of two components describing the occurrence and intensity series, respectively. Binary logistic regression is used to fit the occurrence data, and the intensity series is modeled by a continuous-valued right-skewed distribution, such as gamma, Weibull or lognormal. The precipitation series is then modeled using the joint density and standard software for generalized linear models can be used to perform the computations. A drawback of these precipitation models is that they do not produce a sufficiently heavy upper tail for the distribution of daily precipitation amounts; they tend to underestimate the frequency of large storms. In this study we adapted the approach of Furrer and Katz (2008) based on hybrid distributions in order to correct for this shortcoming. In particular we applied hybrid gamma – generalized Pareto (GP) and hybrid Weibull–GP distributions to develop a stochastic precipitation model for daily rainfall at Ihtiman in western Bulgaria. We report the results of simulations designed to compare the models based on the hybrid distributions and those based on the standard distributions. Some potential difficulties are outlined.
Flood risk analysis of the Limpopo River basin through past evolution reconstruction and geomorphological approach
Authors: Spaliviero M. , De Dapper M. , Maló S.
Published: February 2014

Abstract. This research reconstructs the past evolution of the Limpopo River, a transboundary system located in south-eastern Africa, and describes its geomorphological settings through literature review and field work activities, with aim to analyse the risk of floods in the basin. Major changes have occurred since the late Jurassic – early Cretaceous period due to successive tectonic events. The paper demonstrates that the apparently abandoned drainage conformation of the palaeo-Limpopo in the upper and middle stretches of the river constitutes today preferential flood-prone areas in case of major rainfall events. An important palaeo-delta is identified in the lower Limpopo, which imposes a particular drainage pattern to the floodplain in Mozambique and influences the floods dynamics at present. The adopted method is helpful in determining flood risk in a data-scarce area showing complex fluvial dynamics, and allows identifying unsuitable locations for human settlements.
Enhancing the accuracy of automatic eddy detection and the capability of recognizing the multi-core structures from maps of sea level anomaly
Authors: Yi J. , Du Y. , He Z. , Zhou C.
Published: February 2014

Abstract. Automated methods are important for automatically detecting mesoscale eddies in large volumes of altimeter data. While many algorithms have been proposed in the past, this paper presents a new method, called hybrid detection (HD), to enhance the eddy detection accuracy and the capability of recognizing eddy multi-core structures from maps of sea level anomaly (SLA). The HD method has integrated the criteria of the Okubo–Weiss (OW) method and the sea surface height-based (SSH-based) method, two commonly used eddy detection algorithms. Evaluation of the detection accuracy shows that the successful detection rate of HD is ~ 96.6% and the excessive detection rate is ~ 14.2%, which outperforms the OW and those methods using SLA extrema to identify eddies. The capability of recognizing multi-core structures and its significance in tracking eddy splitting or merging events have been illustrated by comparing with the detection results of different algorithms and observations in previous literature.
The impact of ice layers on gas transport through firn
Authors: Keegan K. , Albert M. R. , Baker I.
Published: February 2014

Abstract. Typically, gas transport through firn is modeled in the context of an idealized firn column. However, in natural firn, imperfections are present which may alter transport dynamics in ways that may reduce the accuracy of climate records. For example, ice layers have been found in several firn cores collected in the polar regions. Here, we examined the effects of two ice layers found in a NEEM, Greenland firn core on gas transport through the firn. Both ice layers were somewhat permeable. However, only the shallower ice layer was significantly less permeable than the surrounding firn and is therefore likely to retard gas transport. Large closed bubbles were found in one ice layer, which would contain older atmospheric samples than expected. Theses bubbles are likely to significantly bias age estimates. Conversely, the permeability and thickness of ice layers at NEEM suggest that they will not significantly bias the expected firn air concentration profiles at the present spatial resolution at which these data are collected. Therefore, ice layers do not need to be accounted for in gas transport models at NEEM. However, the microstructure of these ice layers indicates that larger melting events could significantly bias ice core records.
El estudio de la comunicación interna en el contexto del grado de publicidad y RR PP de la universidad de Cádiz
Authors: Marín Dueñas Pedro Pablo , García García María
Published: February 2014

Frente a la creciente importancia y necesidad de comunicación con los públicos que tienen las organizaciones de todo tipo, la atención que las empresas prestan a la comunicación interna es todavía escasa. A nivel material la comunicación interna adolece de presupuestos poco consolidados y de personal poco cualificado para su gestión. Además, a nivel psicológico recibe escasa atención desde las direcciones de las organizaciones. Numerosos autores (Piñuel, 1997: 103; Villafañe, 1999: 301; Hernández, 1991: 268) han puesto de manifiesto la escasa importancia que le otorgan las empresas a este tipo de comunicación. Formar a universitarios competentes en este tipo de comunicación debería ayudar a solventar esta situación. De acuerdo con el Libro blanco de los títulos de grado en Ciencias de la Comunicación los estudiantes del grado de Publicidad y Relaciones Públicas, como gestores de la comunicación corporativa, serán capaces de gestionar la comunicación interna de la empresa correctamente. En este trabajo se analiza el proceso de aprendizaje de los estudiantes del Grado en Publicidad y Relaciones Públicas de la Universidad de Cádiz desde el punto de vista de la formación en comunicación interna. De esta forma se reflexiona sobre el propio proceso de aprendizaje de la comunicación interna y se detectan carencias presentes que permitan prever insuficiencias futuras. Para ello se eligió a los 119 alumnos de la asignatura de Sistemas de Comunicación Empresarial I a quienes se les encargó la tarea de desarrollar un plan de comunicación interna para pequeñas y medianas empresas creadas por ellos mismos en el que desarrollasen un análisis situacional, estrategias, objetivos, y herramientas para poder llevar a cabo la implementación real de dicho plan. Los resultados muestran dificultades para definir los públicos internos de una organización que se traducen en objetivos y herramientas poco acordes a un plan de comunicación interna. Esta confusión podría justificar la escasa concienciación con la comunicación interna detectada
Compensation Ethics and Organizational Commitment
Authors: Moriarty Jeffrey
Published: February 2014

If an employee is committed to his firm—if he is “attached” or “bound” to it—then his firm may be able to obtain a discount on his labor. This paper asks: Is it wrong for firms to do so? If we understand just or fair pay solely in terms of voluntary agreements between employers and employees, the answer seems to be ‘no.’ Against this, I argue that, in some cases, it is ‘yes.’ In particular, it is wrong for firms to try to obtain discounts on their committed employees’ labor when their employees reasonably expect that they will not try to obtain them. In the process, I probe the limits of exploitation and question the relevance of contribution to fairness in compensation.
A Case Report of Visual Disturbance Caused by Thrombosis of the Superior Sagittal Sinus
Authors: Daiki Taniyama  , Tsuyoshi Torii  , Junichiro Kuga  , Yoriko Dodo  , Hitomi Tanaka  , Yoshimasa Sueda  , Kiyomi Taniyama
Published: February 2014

Superior sagittal sinus thrombosis is a rare condition caused by several diseases including malignancy. Major symptoms include headache, seizure, and motor weakness. Ocular sign is a minor symptom. The present case had visual disturbance caused by thrombosis of the superior sagittal sinus, which is an extremely rare case that was treated successfully by our team.
Chocs de prix internationaux et transmission : cas du marché du riz au Burkina Faso
Authors: Badolo Félix
Published: February 2014

Comment les marchés des produits agricoles dans les pays en développement répondent-ils aux chocs de prix sur les marchés internationaux est une question cruciale en économie agricole qui n’est pas totalement résolue. La hausse des prix des produits agricoles sur les marchés internationaux durant la période 2006-2008 a entraîné une flambée des prix intérieurs dans certains pays en développement, mais cela n’a pas été le cas dans d’autres pays. La littérature empirique sur l’analyse de l’ampleur de la transmission des chocs des prix internationaux aux prix intérieurs dans les pays en développement reste très mitigée. L’objectif de cet article est d’évaluer la relation entre le prix du riz importé au Burkina Faso et le prix international, à partir des tests de coïntégration linéaires et non linéaires (modèle autorégressif à seuil ou modèle TAR). L’analyse empirique se base sur des séries mensuelles de prix pour deux marchés du Burkina Faso : le marché de Sankaryaré à Ouagadougou et le marché de Dori au nord du pays. Les résultats montrent que les prix du riz importé sur ces deux marchés sont intégrés au prix international. L’élasticité de transmission de long terme apparaît être importante. Le modèle TAR révèle une transmission asymétrique dont l’ampleur diffère en fonction de la nature des chocs. Les hausses du prix international se transmettent plus rapidement aux prix intérieurs par rapport aux baisses. Ces résultats s’expliquent par le pouvoir de marché des intermédiaires commerciaux, les coûts de transport et les mécanismes d’intervention du gouvernement.
La valeur psychologique du temps : une synthèse de la littérature
Authors: de La Bruslerie Hubert , Pratlong Florent
Published: February 2014

Cet article procède à une synthèse de la littérature sur la question de la valeur psychologique du temps. Il discute des différents déterminants du taux d’actualisation et la possibilité d’avoir une fonction d’escompte de type hyperbolique. L’approche historique permet de retracer les origines du concept de valeur psychologique du temps. Ce concept est ensuite rediscuté dans le cadre de la théorie des perspectives, en considérant que l’utilité ressentie de l’agent vient modifier la structure de sa valeur psychologique du temps. L’analyse des résultats empiriques et des méthodologies d’identification permet de mettre en évidence que motifs individuels et psychologiques conditionnent le caractère intertemporel des choix.
Worker Education in South Africa: Lessons and contradictions
Authors: Vally Salim , wa Bofelo Mphutlane , Treat John
Published: February 2014

Worker education played a crucial role in the development of the trade union movement in South Africa and in the broader struggle for social transformation. This article reviews key moments and dynamics in the trajectory of worker education in South Africa. We argue that international developments, the rise of neoliberalism, and the negotiated compromise between the African National Congress (ANC) and the apartheid state, as well as corporatism resulted in changes to worker education. While the latter as it existed in the past has weakened, the centre of gravity has shifted to community organizations where various forms of learning and creativity continue. Despite the challenges and setbacks of recent years, there remains a significant legacy and influence of the traditions of worker education and militant trade unionism in South Africa, which can and should be drawn upon.