bluuebunny/crossref_metadata_2025 huggingface dataset:
Fascin1 Promotes Cell Migration of Mature Dendritic Cells
Authors: Yamakita Yoshihiko , Matsumura Fumio , Lipscomb Michael W. , Chou Po-chien , Werlen Guy , Burkhardt Janis K. , Yamashiro Shigeko
Published: January 2011

Dendritic cells (DCs) play central roles in innate and adaptive immunity. Upon maturation, DCs assemble numerous veil-like membrane protrusions, disassemble podosomes, and travel from the peripheral tissues to lymph nodes to present Ags to T cells. These alterations in morphology and motility are closely linked to the primary function of DCs, Ag presentation. However, it is unclear how and what cytoskeletal proteins control maturation-associated alterations, in particular, the change in cell migration. Fascin1, an actin-bundling protein, is specifically and greatly induced upon maturation, suggesting a unique role for fascin1 in mature DCs. To determine the physiological roles of fascin1, we characterized bone marrow-derived, mature DCs from fascin1 knockout mice. We found that fascin1 is critical for cell migration: fascin1-null DCs exhibit severely decreased membrane protrusive activity. Importantly, fascin1-null DCs have lower chemotactic activity toward CCL19 (a chemokine for mature DCs) in vitro, and in vivo, Langerhans cells show reduced emigration into draining lymph nodes. Morphologically, fascin1-null mature DCs are flatter and fail to disassemble podosomes, a specialized structure for cell-matrix adhesion. Expression of exogenous fascin1 in fascin1-null DCs rescues the defects in membrane protrusive activity, as well as in podosome disassembly. These results indicate that fascin1 positively regulates migration of mature DCs into lymph nodes, most likely by increasing dynamics of membrane protrusions, as well as by disassembling podosomes.
Distinct Different Contributions of the Alternative and Classical Complement Activation Pathway for the Innate Host Response during Sepsis
Authors: Dahlke Katja , Wrann Christiane D. , Sommerfeld Oliver , Soßdorf Maik , Recknagel Peter , Sachse Svea , Winter Sebastian W. , Klos Andreas , Stahl Gregory L. , Ma Yuanyuan Xu , Claus Ralf A. , Reinhart Konrad , Bauer Michael , Riedemann Niels C.
Published: January 2011

Complement activation represents a crucial innate defense mechanism to invading microorganisms, but there is an eminent lack of understanding of the separate contribution of the different complement activation pathways to the host response during sepsis. We therefore investigated different innate host immune responses during cecal ligation and puncture (CLP)-induced sepsis in mice lacking either the alternative (fD−/−) or classical (C1q−/−) complement activation pathway. Both knockout mice strains showed a significantly reduced survival and increased organ dysfunction when compared with control mice. Surprisingly, fD−/− mice demonstrated a compensated bacterial clearance capacity as control mice at 6 h post CLP, whereas C1q−/− mice were already overwhelmed by bacterial growth at this time point. Interestingly, at 24 h after CLP, fD−/− mice failed to clear bacteria in a way comparable to control mice. However, both knockout mice strains showed compromised C3 cleavage during sepsis. Investigating potential causes for this discrepancy, we were able to demonstrate that despite normal bacterial clearance capacity early during the onset of sepsis, fD−/− mice displayed increased inflammatory cytokine generation and neutrophil recruitment into lungs and blood when compared with both control- and C1q−/− mice, indicating a potential loss of control over these immune responses. Further in vitro experiments revealed a strongly increased Nf-κB activation capacity in isolated neutrophils from fD−/− mice, supporting this hypothesis. Our results provide evidence for the new concept that the alternative complement activation pathway exerts a distinctly different contribution to the innate host response during sepsis when compared with the classical pathway.
Distinct Functions for the Glycans of Tapasin and Heavy Chains in the Assembly of MHC Class I Molecules
Authors: Rizvi Syed Monem , Del Cid Natasha , Lybarger Lonnie , Raghavan Malini
Published: January 2011

Complexes of specific assembly factors and generic endoplasmic reticulum (ER) chaperones, collectively called the MHC class I peptide-loading complex (PLC), function in the folding and assembly of MHC class I molecules. The glycan-binding chaperone calreticulin (CRT) and partner oxidoreductase ERp57 are important in MHC class I assembly, but the sequence of assembly events and specific interactions involved remain incompletely understood. We show that the recruitments of CRT and ERp57 to the PLC are codependent and also dependent upon the ERp57 binding site and the glycan of the assembly factor tapasin. Furthermore, the ERp57 binding site and the glycan of tapasin enhance β2m and MHC class I heavy (H) chain recruitment to the PLC, with the ERp57 binding site having the dominant effect. In contrast, the conserved MHC class I H chain glycan played a minor role in CRT recruitment into the PLC, but impacted the recruitment of H chains into the PLC, and glycan-deficient H chains were impaired for tapasin-independent and tapasin-assisted assembly. The conserved MHC class I glycan and tapasin facilitated an early step in the assembly of H chain–β2m heterodimers, for which tapasin–ERp57 or tapasin–CRT complexes were not required. Together, these studies provide insights into how PLCs are constructed, demonstrate two distinct mechanisms by which PLCs can be stabilized, and suggest the presence of intermediate H chain-deficient PLCs.
Activation Receptor-Induced Tolerance of Mature NK Cells In Vivo Requires Signaling through the Receptor and Is Reversible
Authors: Bolanos Fred D. , Tripathy Sandeep K.
Published: January 2011

NK cell responses are determined by signals received through activating and inhibitory cell surface receptors. Ly49H is an NK cell-specific activating receptor that accounts for the genetic resistance to murine CMV (MCMV). The Ly49H receptor has been shown to interact with two adaptor proteins (DAP12 and DAP10). In the context of MCMV infection, interaction of m157 (the MCMV-encoded ligand for Ly49H) with Ly49H results in activation of Ly49H-expressing NK cells. Chronic exposure of Ly49H with m157, however, induces tolerance in these same cells. The mechanism of this tolerance remains poorly understood. Using a transgenic mouse model, we demonstrate that induction of tolerance in Ly49H+ NK cells by chronic exposure to m157, in vivo, requires signaling through the Ly49H adaptor protein DAP12, but not the DAP10 adaptor protein. Furthermore, mature Ly49H-expressing NK cells from wild-type mice can acquire a tolerant phenotype by 24 h posttransfer into a transgenic C57BL/6 mouse that expresses m157. The tolerant phenotype can be reversed, in vivo, if tolerant NK cells are transferred to mice that do not express the m157 protein. Thus, continuous activating receptor engagement can induce a transient tolerance in mature NK cells in vivo. These observations provide new insight into how activating receptor engagement shapes NK cell function and has important implications in how NK cells respond to tumors and during chronic viral infection.
An experimental analysis of harmful algae–zooplankton interactions and the ultimate defense
Authors: Remmel Emily J. , Kohmescher Nicole , Larson James H. , Hambright K. David
Published: January 2011

We examined effects of the invasive, toxigenic haptophyte Prymnesium parvum on grazing rates, feeding behaviors, and life‐history characteristics of clonal lineages of three daphniid zooplankton species. Grazing experiments revealed similar clearance rates for P. parvum and a common green alga. Behavioral observations revealed no significant effects of P. parvum on daphniid feeding behaviors after 30 min, but major declines in appendage beat rates after 1 h. Chronic exposure (10 d) to P. parvum resulted in severe reductions in daphniid growth rates, age at first reproduction, fecundity, and survivorship at densities as low as 7750 cells mL−1. Thus, in addition to direct fish mortality during P. parvum blooms of 50,000–200,000 cells mL−1, the entire food web of an invaded system may be subjected to potentially severe negative consequences even at nonbloom densities of P. parvum.
Effect of seasonal biogenic silica variations on dissolved silicon fluxes and isotopic signatures in the Congo River
Authors: Hughes Harold J. , Sondag Francis , Cocquyt Christine , Laraque Alain , Pandi Albert , André Luc , Cardinal Damien
Published: January 2011

We report 2 yr of monthly data from the Congo River (the second largest river in the world) on dissolved silicon concentrations, biogenic silica particle concentrations, isotopic signatures of dissolved silicon, and biogenic siliceous particle counts. Diatoms predominated in the biogenic silica fraction, especially during low flow; phytoliths and sponge spicules were more abundant than diatoms only during the rainy season, when biogenic silica fluxes are low. Biological processes dominated the seasonal variations of the dissolved δ30Si ratio that are superimposed on a constant abiotic δ30Si value of +0.70‰ ± 0.05‰ throughout the year. The measured biogenic silica concentration is less than the amount required to explain the monthly variations of dissolved δ30Si signatures. We use these signatures and a Rayleigh isotopic fractionation model to calculate that 82% ± 7% of the diatoms produced each month would be exported out of the water column, probably through settling in the Malebo Pool or further upstream. The uptake of dissolved silicon by diatoms during low water flow periods could explain the absence of the dilution effect observed for the other major elements. Annual Si export to the estuary is 1.17 × 1010 mol yr−1 in the form of biogenic silica and 2.23 × 1011 mol< yr−1 in dissolved Si form, with a mean dissolved δ30Si of +0.96‰ ± 0.27‰. Phytoliths make only a minor contribution to the annual biogenic silica flux, and dissolved Si fluxes predominate over biogenic Si fluxes.
Public Entities as Undertakings under Competition Rules
Authors: Repas Martina
Published: January 2011

This paper deals with undertakings, i.e., entities that are obliged to act in accordance with competition rules. This issue is one of the key elements for the application of competition rules. Its importance derives from severe consequences in case of breach of these rules that may give rise to fines, nullity of agreements, and in some regulations, even to criminal offenses. For this purpose, the paper explains the notion of ‘undertaking’ as understood in the EU and Slovenian competition law systems. It deals especially with public bodies such as states, local communities, public institutes, and others that can also qualify as undertakings when they perform activities for pay in the market, and are thus obliged to follow competition rules. A review of the case law shows that many public entities have been under the Competition Authority’s investigation of infringements of competition rules.

KEYWORDS: • competition law • public authority • undertaking • economic activity • association of undertakings • single economic entity • EU • Slovenia
The political effects of local property taxation in Norway
Authors: Hansen Tore , Noer Hanne
Published: January 2011

The property taxation is perhaps the most controversial policy issue in Norwegian local authorities. Municipalities enjoy autonomy to decide whether or not to introduce property taxation. However, national legislation sets limits on property tax rates. The conflict over the property taxation follows the traditional left-right ideological division. This study analyses whether the introduction of property taxation in individual municipalities leads to political repercussions for the pro-tax parties in terms of weakened voter support. By using the data from the 2003 and 2007 local elections, the analysis reveals that, contrary to our expectations, the support for the left-wing parties is stronger in the municipalities that have introduced such taxes than in other municipalities. There are no signs that the pro-tax parties are being punished by the voters. To the extent that there are any such negative repercussions, it seems that the right-wing anti-tax parties suffer vote losses, but these losses are moderate.

KEYWORDS: • local politics • property taxation • economic voting • ideological conflicts
European Union Enlargement and the new Peripheral Regions: Political, Economic and Social Aspects and Related Issues – A Case of Warmia and Mazury Region
Authors: Żukowski Arkadiusz , Chelminiak Marcin
Published: January 2011

This paper analyses the problems of the new peripheral regions after the European Union enlargement. The last EU enlargements in 2004 and 2007 were the logical consequences of political, social and economic changes associated with the break-up of the Soviet Union and the disintegration of the Communist Bloc. These two enlargements led to substantial geopolitical consequences. The European Union’s demographic and territorial potential increased by around one-third. At the same time, the European Union structures moved east and southwards. In 2004, one of the Polish regions, the Warmia and Mazury region, faced some new challenges associated with the Polish accession to the EU. The years of Poland’s membership in the European Union have been a period of gaining experience in submitting EU projects for the region, and in allocating financial resources properly. The total effect of this period is rather positive. However, we must not forget that many negative economic and social phenomena still occur (e.g., a high unemployment rate, emigration of young educated people, etc.). Politically, a new challenge for the Warmia and Mazury region is going to be a continuation and development of the cross-border cooperation with the Kaliningrad region. Poland’s accession to the EU has had no positive impact on improving the Polish-Russian relations at the central decision-making level.

KEYWORDS: • European Union • regional development • new peripheral regions • Warmia and Mazury region
Alternative Service Delivery Arrangements at the Municipal Level in Slovenia and Croatia
Authors: Grafenauer Božo , Klarić Mirko
Published: January 2011

There has been extensive development and rapid expansion of alternative forms of public service provision at the local level in Slovenia and Croatia over the last twenty years. During that time, the private sector began to be intensively involved in performing public service activities and in investment financing for the public infrastructure construction, i.e., by the gradual introduction of the new forms of cooperation between the public and private sectors. However, the new Public-Private Partnership Act, which came into force in Slovenia in 2007 and in Croatia in 2008, signified a milestone in the legal regulation of alternative forms of public service delivery. The Act introduces European comparable arrangements and forms of public-private partnerships that can be either contractual or equity-based. Within public services, local public goods and services are mostly provided by public enterprises and institutions, and by awarding public service concessions. Other forms of public-private partnerships primarily include some forms of build-operate-transfer project financing.

KEYWORDS: • local authorities • local self-government • local public services • public-private partnerships • concession • Slovenia • Croatia
Corrosion Behavior of Pressure Vessel Steel Exposed to Residual Bubbles After Cavitation Bubble Collapse
Authors: Soyama H.
Published: January 2011

The corrosion potential of pressure vessel steel after exposure to residual bubbles and the open-circuit potential of Pt during cavitation were measured to investigate the corrosion behavior induced by residual bubbles after cavitation bubble collapse (as distinct from erosion caused by cavitation impact). The surfaces of the corrosion specimens were also investigated using x-ray photoelectron spectroscopy. It was shown that the residual bubbles shift the potential of a Pt electrode to a more anodic potential and that the oxide layer induced by the residual bubbles is different from that produced by normal water without residual bubbles.
Detecting Critical Crevice Temperature for Duplex Stainless Steels in Chloride Solutions
Authors: Han D. , Jiang Y. , Deng B. , Zhang L. , Gao J. , Tan H. , Li J.
Published: January 2011

A simple and rapid electrochemical method for the evaluation of crevice corrosion in duplex stainless steels (DSS) is described. Three types of DSS—namely, UNS S32101, UNS S31803, and UNS S32750—were tested in 1 mol/L sodium chloride (NaCl) solutions. Results showed good reproducibility with a typical standard deviation of below 3°C. The critical pitting temperature (CPT) for the same specimens was also investigated in 1 mol/L NaCl solutions. An approximately 20°C decrease from CPT to critical crevice temperature (CCT) was observed and subsequently explained. Then, the morphologies of crevice corrosion were studied using scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDS) method. The SEM/EDS study revealed that the ferrite phase was the site where preferential dissolution took place at the initiation step of crevice corrosion, which was in accordance with the prediction by calculating the critical crevice index. Moreover, repassivation was detected with the development of crevice corrosion. The reason was clarified by combining the results obtained with a successful diffusion model, and eventually the crevice corrosion progress was illustrated schematically.
Effects of Environmental and Metallurgical Factors on the Stress Corrosion Cracking of Carbon Steel in Fuel-Grade Ethanol
Authors: Beavers J.A. , Gui F. , Sridhar N.
Published: January 2011

This paper presents the results of a research program to study the effects of metallurgical variables, ethanol-gasoline blends, dissolved oxygen, and inhibitors on the stress corrosion cracking (SCC) of carbon steel in ethanol. The study utilized both slow strain rate (SSR) and fatigue precracked compact tension (CT) tests to characterize the effect of metallurgical and environmental variables on SCC. Metallurgical factors, including steel grade within a range of pipeline grades, welds, and heat-affected zone, do not appear to have a significant effect on the degree or rate of SCC. In terms of environmental factors, it is shown that SCC does not occur even in a fully aerated condition if the ethanol-gasoline blends contain less than approximately 15 vol% ethanol; SCC susceptibility and crack growth rate are higher in 50 vol% ethanol gasoline blend (E-50) than in either lower or higher ethanol concentration blends; oxygen scavenging can be an effective method to prevent SCC; water content above 4.5 wt% prevents SCC in ethanol; and fatigue precracked CT tests show similar trends in SCC susceptibility as SSR tests.
Heterogeneous ice nucleation: bridging stochastic and singular freezing behavior
Authors: Niedermeier D. , Shaw R. A. , Hartmann S. , Wex H. , Clauss T. , Voigtländer J. , Stratmann F.
Published: January 2011

Abstract. Heterogeneous ice nucleation, a primary pathway for ice formation in the atmosphere, has been described alternately as being stochastic, in direct analogy with homogeneous nucleation, or singular, with ice nuclei initiating freezing at deterministic temperatures. We present an idealized model that bridges these stochastic and singular descriptions of heterogeneous ice nucleation. This "soccer ball" model treats statistically similar particles as being covered with surface sites (patches of finite area) characterized by different nucleation barriers, but with each surface site following the stochastic nature of ice embryo formation. The model provides a phenomenological explanation for seemingly contradictory experimental results obtained in our research groups. We suggest that ice nucleation is fundamentally a stochastic process but that for realistic atmospheric particle populations this process can be masked by the heterogeneity of surface properties. Full evaluation of the model will require experiments with well characterized ice nucleating particles and the ability to vary both temperature and waiting time for freezing.
Toward unification of the multiscale modeling of the atmosphere
Authors: Arakawa A. , Jung J.-H. , Wu C.-M.
Published: January 2011

Abstract. This paper suggests two possible routes to achieve the unification of model physics in coarse- and fine-resolution atmospheric models. As far as representation of deep moist convection is concerned, only two kinds of model physics are used at present: highly parameterized as in the conventional general circulation models (GCMs) and explicitly simulated as in the cloud-resolving models (CRMs). Ideally, these two kinds of model physics should be unified so that a continuous transition of model physics from one kind to the other takes place as the resolution changes. With such unification, the GCM can converge to a global CRM (GCRM) as the grid size is refined. ROUTE I for unification continues to follow the parameterization approach, but uses a unified parameterization that is applicable to any horizontal resolutions between those typically used by GCMs and CRMs. It is shown that a key to construct such a unified parameterization is to eliminate the assumption of small fractional area covered by convective clouds, which is commonly used in the conventional cumulus parameterizations either explicitly or implicitly. A preliminary design of the unified parameterization is presented, which demonstrates that such an assumption can be eliminated through a relatively minor modification of the existing mass-flux based parameterizations. Partial evaluations of the unified parameterization are also presented. ROUTE II for unification follows the "multi-scale modeling framework (MMF)" approach, which takes advantage of explicit representation of deep moist convection and associated cloud-scale processes by CRMs. The Quasi-3-D (Q3-D) MMF is an attempt to broaden the applicability of MMF without necessarily using a fully three-dimensional CRM. This is accomplished using a network of cloud-resolving grids with gaps. An outline of the Q3-D algorithm and highlights of preliminary results are reviewed.
A novel technique for extracting clouds base height using ground based imaging
Authors: Hirsch E. , Agassi E. , Koren I.
Published: January 2011

Abstract. The height of a cloud in the atmospheric column is a key parameter in its characterization. Several remote sensing techniques (passive and active, either ground-based or on space-borne platforms) and in-situ measurements are routinely used in order to estimate top and base heights of clouds. In this article we present a novel method that combines thermal imaging from the ground and sounded wind profile in order to derive the cloud base height. This method is independent of cloud types, making it efficient for both low boundary layer and high clouds. In addition, using thermal imaging ensures extraction of clouds' features during daytime as well as at nighttime. The proposed technique was validated by comparison to active sounding by ceilometers (which is a standard ground based method), to lifted condensation level (LCL) calculations, and to MODIS products obtained from space. As all passive remote sensing techniques, the proposed method extracts only the height of the lowest cloud layer, thus upper cloud layers are not detected. Nevertheless, the information derived from this method can be complementary to space-borne cloud top measurements when deep-convective clouds are present. Unlike techniques such as LCL, this method is not limited to boundary layer clouds, and can extract the cloud base height at any level, as long as sufficient thermal contrast exists between the radiative temperatures of the cloud and its surrounding air parcel. Another advantage of the proposed method is its simplicity and modest power needs, making it particularly suitable for field measurements and deployment at remote locations. Our method can be further simplified for use with visible CCD or CMOS camera (although nighttime clouds will not be observed).
Particular uncertainties encountered in using a pre-packaged SEBS model to derive evapotranspiration in a heterogeneous study area in South Africa
Authors: Gibson L. A. , Münch Z. , Engelbrecht J.
Published: January 2011

Abstract. The focus of this paper is on the pre-packaged version of SEBS in ILWIS and the sensitivity of SEBS to some parameters over which the user has some control when using this version of the model, in order to make informed choices to limit uncertainties. The sensitivities of SEBS to input parameters are related to daily ET rather than energy flux results since this is of interest to water managers and other users of the results of the SEBS model. This paper describes some of the uncertainties introduced by the sensitivity of the SEBS model to (a) land surface temperature and air temperature gradient, (b) the choice of fractional vegetation formula, (c) displacement height and the height at which wind speed is measured, and (d) study area heterogeneity. It was shown that SEBS is sensitive to land surface temperature and air temperature gradient and the magnitude of this sensitivity depended on the land cover and whether or not the wet-limit had been reached. The choice of fractional vegetation cover formula was shown to influence the daily ET results by up to 0.7 mm. It was shown that the height of the vegetation canopy should be considered in relation to the weather station reference height to avoid the sensible heat flux from becoming unsolvable due to a negative ln calculation. Finally the study area was shown to be heterogeneous although the resolution at which fluxes were calculated did not significantly impact on energy partitioning results. The differences in the upscaling from evaporative fraction to daily ET at varying resolutions observed implies that the heterogeneity may play the biggest role in the upscaling and the influence of albedo on this calculation should be studied.
Combining remote sensing and GIS climate modelling to estimate daily forest evapotranspiration in a Mediterranean mountain area
Authors: Cristóbal J. , Poyatos R. , Ninyerola M. , Llorens P. , Pons X.
Published: January 2011

Abstract. Evapotranspiration monitoring allows us to assess the environmental stress on forest and agricultural ecosystems. Nowadays, Remote Sensing and Geographical Information Systems (GIS) are the main techniques used for calculating evapotranspiration at catchment and regional scales. In this study we present a methodology, based on the energy balance equation (B-method), that combines remote sensing imagery with GIS climate modelling to estimate daily evapotranspiration (ETd) for several dates between 2003 and 2005. The three main variables needed to compute ETd were obtained as follows: (i) Land surface temperature by means of the Landsat-5 TM and Landsat-7 ETM+ thermal band, (ii) air temperature by means of multiple regression analysis and spatial interpolation from meteorological ground stations data at satellite pass, and (iii) net radiation by means of the radiative balance. We calculated ETd using remote sensing data at different spatial and temporal scales (TERRA/AQUA MODIS and Landsat-5 TM/Landsat-7 ETM+) and combining three different approaches to calculate the B parameter. We then compared these estimates with sap flow measurements from a Scots pine (Pinus sylvestris L.) stand in a Mediterranean mountain area. This procedure allowed us to better understand the limitations of ETd modelling and how it needs to be improved, especially in heterogeneous forest areas. The method using Landsat data resulted in a good agreement, with a mean RMSE value of about 0.6 mm day−1 and an estimation error of ±30%. The poor agreement obtained using MODIS data reveals that ETd retrieval from coarse resolution remote sensing data is troublesome in these heterogeneous areas, and therefore further research is necessary on this issue.
Hydrological differentiation and spatial distribution of high altitude wetlands in a semi-arid Andean region derived from satellite data
Authors: Otto M. , Scherer D. , Richters J.
Published: January 2011

Abstract. High Altitude Wetlands of the Andes (HAWA) are unique types of wetlands within the semi-arid high Andean region. Knowledge about HAWA has been derived mainly from studies at single sites within different parts of the Andes at only small time scales. On the one hand HAWA depend on water provided by glacier streams, snow melt or precipitation. On the other hand, they are suspected to influence hydrology through water retention and vegetation growth altering stream flow velocity. We derived HAWA land cover from satellite data at regional scale and analysed changes in connection with precipitation over the last decade. Perennial and temporal HAWA subtypes can be distinguished by seasonal changes of photosynthetically active vegetation (PAV) indicating the perennial or temporal availability of water during the year. HAWA have been delineated within a region of 11 000 km2 situated in the Northwest of Lake Titicaca. The multi temporal classification method used Normalized Differenced Vegetation Index (NDVI) and Normalized Differenced Infrared Index (NDII) data derived from two Landsat ETM+ scenes at the end of austral winter (September 2000) and at the end of austral summer (May 2001). The mapping result indicates an unexpected high abundance of HAWA covering about 800 km2 of the study region (6%). Annual HAWA mapping was computed using NDVI 16-day composites of Moderate Resolution Imaging Spectroradiometer (MODIS). Analyses on the reletation between HAWA and precipitation was based on monthly precipitation data of the Tropical Rain Measurement Mission (TRMM 3B43) and MODIS Eight Day Maximum Snow Extent data (MOD10A2) from 2000 to 2010. We found HAWA subtype specific dependencies to precipitation conditions. Strong relation exists between perennial HAWA and snow fall (r2: 0.82) in dry austral winter months (June to August) and between temporal HAWA and precipitation (r2: 0.75) during austral summer (March to May). Annual spatial patterns of perennial HAWA indicated spatial alteration of water supply for PAV up to several hundred metres at a single HAWA site.
Debye-scale solitary structures measured in a beam-plasma laboratory experiment
Authors: Lefebvre B. , Chen L.-J. , Gekelman W. , Kintner P. , Pickett J. , Pribyl P. , Vincena S.
Published: January 2011

Abstract. Solitary electrostatic pulses have been observed in numerous places of the magnetosphere such as the vicinity of reconnection current sheets, shocks or auroral current systems, and are often thought to be generated by energetic electron beams. We present results of a series of experiments conducted at the UCLA large plasma device (LAPD) where a suprathermal electron beam was injected parallel to a static magnetic field. Micro-probes with tips smaller than a Debye length enabled the detection of solitary pulses with positive electric potential and half-widths 4–25 Debye lengths (λDe), over a set of experiments with various beam energies, plasma densities and magnetic field strengths. The shape, scales and amplitudes of the structures are similar to those observed in space, and consistent with electron holes. The dependance of these properties on the experimental parameters is shown. The velocities of the solitary structures (1–3 background electron thermal velocities) are found to be much lower than the beam velocities, suggesting an excitation mechanism driven by parallel currents associated to the electron beam.
Scale-dependent measurement and analysis of ground surface temperature variability in alpine terrain
Authors: Gubler S. , Fiddes J. , Gruber S. , Keller M.
Published: January 2011

Abstract. Measurements of environmental variables are often used to validate and calibrate physically-based models. Depending on their application, models are used at different scales, ranging from few meters to tens of kilometers. Environmental variables can vary strongly within the grid cells of these models. Validating a model with a single measurement is therefore delicate and susceptible to induce bias in further model applications. To address the question of uncertainty associated with scale in permafrost models, we present data of 390 spatially-distributed ground surface temperature measurements recorded in terrain of high topographic variability in the Swiss Alps. We illustrate a way to program, deploy and refind a large number of measurement devices efficiently, and present a strategy to reduce data loss reported in earlier studies. Data after the first year of deployment is presented. The measurements represent the variability of ground surface temperatures at two different scales ranging from few meters to some kilometers. On the larger scale, the dependence of mean annual ground surface temperature on elevation, slope, aspect and ground cover type is modelled with a linear regression model. Sampled mean annual ground surface temperatures vary from −4 °C to 5 °C within an area of 16 km2 subject to elevational differences of approximately 1000 m. The measurements also indicate that mean annual ground surface temperatures vary up to 6 °C (i.e., from −2 °C to 4 °C) even within an elevational band of 300 m. Furthermore, variations can be high (up to 2.5 °C) at distances of less than 14 m in homogeneous terrain. The effect of this high variability of an environmental variable on model validation and applications in alpine regions is discussed.
The relationship between organizational commitment and intention to leave: A model of two components of continuance commitment
Authors:   Dept. Organización de Empresas. Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa. Universidad Politécnica de Cataluña. Calle Colom, 11. 08222 Terrassa. jose.maria.sallan@upc.edu, Sallán Jose M. , Simo Pep ,   Dept. Organización de Empresas. Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa. Universidad Politécnica de Cataluña. Calle Colom, 11. 08222 Terrassa. pep.simo@upc. edu, Fernández Vicenc ,   Dept. Organización de Empresas. Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa. Universidad Politécnica de Cataluña. Calle Colom, 11. 08222 Terrassa. vicenc.fernandez@upc.edu, Enache Mihaela ,   Dept. Organización de Empresas. Escuela Técnica Superior de Ingenierías Industrial y Aeronáutica de Terrassa. Universidad Politécnica de Cataluña. Calle Colom, 11. 08222 Terrassa. mihaela.enache@upc.edu
Published: January 2011

The aim of this article is to provide empirical evidence on two questions belonging to the research agenda of organizational commitment research: the possible existence of several facets of continuance commitment, and of non-linear relationships between organizational commitment and various organizational behaviors and their predictors, such as turnover and intention to leave the organization. An empirical research through a survey with 241 respondents has been carried out, and hypotheses have been tested through hierarchic linear regression. The results obtained confirm the relationship between affective commitment and intention to leave found in previous research, and the existence of two distinct components of continuance commitment. There have not been found non-linear relationships between organizational commitment and the intention to leave the organization. One of the most important managerial implications of this research is that in order to reduce turnover, human resource managers should foster affective and continuance organizational commitment among the employees.
Cemented impaction grafting with moulded intramedullary mesh for femoral stem revision – long-term results
Authors: Girard Julien , Riera Philippe , Pearce Olivier , Duquennoy Antoine , Migaud Henri
Published: January 2011

To address femoral bone loss in revision total hip arthroplasty (THA) we developed a technique involving impaction allografting with intramedullary mesh moulded around the revision stem, to prevent excessive cement penetration of the allograft. The length of the revision stem was determined by the extent of femoral bone loss.

Between 1986 and 1998, 32 such procedures were undertaken on 28 patients. The mean pre-operative HHS for function was 22 (range 5 to 42), improving to 41 (range 12 to 47) at final follow-up. Only 1 patient presented with aseptic loosening after revision at 147 months (12.2 years). The 12.5 year survivorship for the stem was 92.8%.

The technique has provided stable and durable reconstruction, with good new bone formation visible radiologically. It is technically demanding and time consuming, but it avoids the previously published problem of massive subsidence within the bone graft.
Tuberculous arthritis in Cambodia
Authors: Swenson Alan K. , Gollogly James G. , Ngiep Ou Cheng , Braidwood Mark
Published: January 2011

Background: Cambodia boasts one of the highest incidences of TB in the world. As such, healthcare providers are experienced with types of extrapulmonary TB such as septic Mycobacterium tuberculosis arthritic infections, not seen in developed countries.

Objective: Examine the incidence and distribution of TB arthritis cases at a Cambodian surgical center, explore the problems of diagnosis and current methods of treatment for this disease.

Methods: The written charts, operation records, and electronic database of patients with clinically diagnosed extrapulmonary TB, confirmed with a positive biopsy between January 2001 and July 2010 were searched. While medical treatment for the TB was given at other facilities, the operations performed and the result for patients with follow-up was reviewed.

Results: Between January 2001 and July 2010, 38 cases of TB arthritis at the CSC in Cambodia were histologically confirmed. Twenty-eight cases affected the lower extremity with the majority affecting the knee and ankle. All 13 patients receiving arthrodesis reported positive surgical outcomes.

Discussion/Conclusion: TB arthritis persists as an ongoing problem at CSC with a significant level of incidence. Arthrodesis is a viable and cost effective mean of treating TB arthritis in Cambodia.
Human IgG inhibits IgA1 protease-dependent adherence of Haemophilus influenza strains to human lung epithelial cells
Authors: He Shiping , Chang Hui-Hsuan , Kuo Hsiu-Maan , Lin Ya-Ling
Published: January 2011

Background: IgA1 protease may enhance the bacterial infection in human beings. However, the molecular mechanism of bacterial adherence to eukaryotic cells is unclear.

Objective: Reveal the mechanisms of IgA1 protease-dependent and non-protease bacterial adherence to eukaryotic cells.

Method: Type I and type II IgA1 proteases from iga genes (GenBank DQ683355 for NTHi465, DQ683356 for NTHi500 and DQ683357 for Nm430) were cloned, expressed, and purified. Cellular assays for adherence of IgA1 protease-producing and -non-producing and typable and nontypable strains of H. influenzae to human lung carcinoma cells (A549) were carried out in the presence of human antibodies.

Results: Adherence of protease-producing strains and non-producing strains to human epithelial cells was significantly dependent on the enzyme activity. In addition, human IgG was an inhibitor to IgA1 proteasedependent adherence of H. influenzae strains to human cells. However, IgA1 antibodies were irrelevant to IgA1 protease-dependent adherence.

Conclusion: IgA1 protease was required for adherence of pathogenic bacteria to human epithelial cells in IgA1 protease-producing bacteria, and human IgG inhibits the adherence, but not for IgA1 protease non-producing bacteria.
Associations between evaluation anxiety, cognitive interference and performance on working memory tasks
Authors: Coy Brent , O'Brien William H. , Tabaczynski Tracy , Northern Jebediah , Carels Robert
Published: January 2011

According to Cognitive Interference Theory, evaluation anxiety leads to increased negative off‐task self‐dialogue which then results in diminished cognitive performance. Given that negative off‐task self‐dialogue is primarily verbal, the phonological loop and central executive components of the working memory system should be most affected by evaluation anxiety. Eighty‐eight participants were randomly assigned to receive evaluation anxiety inducing instructions or supportive instructions prior to administration of three tests (Digit Span, Visual Memory Span, and StroopColour‐Word) that measured the phonological loop, visuospatial sketchpad, and central executive components of working memory. Measures of evaluation anxiety and negative off‐task self‐dialogue were obtained during and after testing. Results showed that participants receiving anxiety inducing instructions reported significantly more evaluation anxiety and off‐task self‐dialogue. They also had significantly lower performance on the Digit Span Test and the StroopColour‐Word Test. Negative off‐task self‐dialogue also mediated the relationship between evaluation anxiety and performance on the Digit Span Test. Copyright © 2011 John Wiley & Sons, Ltd.
Five‐Parameter Grain Boundary Analysis by 3D EBSD of an Ultra Fine Grained CuZr Alloy Processed by Equal Channel Angular Pressing
Authors: Khorashadizadeh A. , Raabe D. , Zaefferer S. , Rohrer G. S. , Rollett A. D. , Winning M.
Published: January 2011

The 3D grain boundary character distribution (GBCD) of a sample subjected to equal channel angular pressing (ECAP) after eight passes and successive annealing at 650 °C for about 10 min is analyzed. The experiments are conducted using a dual beam system, which is a combination of a focused ion beam and a scanning electron microscope to collect a series of electron backscatter diffraction (EBSD) maps of the microstructure (3D EBSD). The data set was aligned and reconstructed to a 3D microstructure. The crystallographic character of the grain boundary planes was determined using three different methods, namely, the line segment method, the stereological method, and the triangular surface mesh method. The line segment and triangular surface mesh methods produce consistent data sets, both yielding approximately a 7% area fraction of coherent twins. These results starkly contrast that of the statistical stereological method, which produced a 44% area fraction of coherent twins.
Charcot‐marie‐tooth disease subtypes and genetic testing strategies
Authors: Saporta Anita S.D. , Sottile Stephanie L. , Miller Lindsey J. , Feely Shawna M.E. , Siskind Carly E. , Shy Michael E.
Published: January 2011

Objective

Charcot‐Marie‐Tooth disease (CMT) affects 1 in 2,500 people and is caused by mutations in more than 30 genes. Identifying the genetic cause of CMT is often necessary for family planning, natural history studies, and for entry into clinical trials. However genetic testing can be both expensive and confusing to patients and physicians.

Methods

We analyzed data from 1,024 of our patients to determine the percentage and features of each CMT subtype within this clinic population. We identified distinguishing clinical and physiological features of the subtypes that could be used to direct genetic testing for patients with CMT.

Results

Of 1,024 patients evaluated, 787 received CMT diagnoses. A total of 527 patients with CMT (67%) received a genetic subtype, while 260 did not have a mutation identified. The most common CMT subtypes were CMT1A, CMT1X, hereditary neuropathy with liability to pressure palsies (HNPP), CMT1B, and CMT2A. All other subtypes accounted for less than 1% each. Eleven patients had >1 genetically identified subtype of CMT. Patients with genetically identified CMT were separable into specific groups based on age of onset and the degree of slowing of motor nerve conduction velocities.

Interpretation

Combining features of the phenotypic and physiology groups allowed us to identify patients who were highly likely to have specific subtypes of CMT. Based on these results, we propose a strategy of focused genetic testing for CMT, illustrated in a series of flow diagrams created as testing guides. ANN NEUROL 2011;69:22–33.
Longitudinal assessment of Aβ and cognition in aging and Alzheimer disease
Authors: Villemagne Victor L. , Pike Kerryn E. , Chételat Gaël , Ellis Kathryn A. , Mulligan Rachel S. , Bourgeat Pierrick , Ackermann Uwe , Jones Gareth , Szoeke Cassandra , Salvado Olivier , Martins Ralph , O'Keefe Graeme , Mathis Chester A. , Klunk William E. , Ames David , Masters Colin L. , Rowe Christopher C.
Published: January 2011

Objective

Assess Aβ deposition longitudinally and explore its relationship with cognition and disease progression.

Methods

Clinical follow‐up was obtained 20 ± 3 months after [11C]Pittsburgh compound B (PiB)‐positron emission tomography in 206 subjects: 35 with dementia of the Alzheimer type (DAT), 65 with mild cognitive impairment (MCI), and 106 age‐matched healthy controls (HCs). A second PiB scan was obtained at follow‐up in 185 subjects and a third scan after 3 years in 57.

Results

At baseline, 97% of DAT, 69% of MCI, and 31% of HC subjects showed high PiB retention. At 20‐month follow‐up, small but significant increases in PiB standardized uptake value ratios were observed in the DAT and MCI groups, and in HCs with high PiB retention at baseline (5.7%, 2.1%, and 1.5%, respectively). Increases were associated with the number of apolipoprotein E ε4 alleles. There was a weak correlation between PiB increases and decline in cognition when all groups were combined. Progression to DAT occurred in 67% of MCI with high PiB versus 5% of those with low PiB, but 20% of the low PiB MCI subjects progressed to other dementias. Of the high PiB HCs, 16% developed MCI or DAT by 20 months and 25% by 3 years. One low PiB HC developed MCI.

Interpretation

Aβ deposition increases slowly from cognitive normality to moderate severity DAT. Extensive Aβ deposition precedes cognitive impairment, and is associated with ApoE genotype and a higher risk of cognitive decline in HCs and progression from MCI to DAT over 1 to 2 years. However, cognitive decline is only weakly related to change in Aβ burden, suggesting that downstream factors have a more direct effect on symptom progression. Ann Neurol 2011;69:181–192.
Biological implications of recreational shore angling and harvest in a marine reserve: the case of Cape Creus
Authors: Font Toni , Lloret Josep
Published: January 2011

Recreational shore fishing along the coast of the marine reserve of Cap de Creus (NW Mediterranean) was studied in 2007 and 2009 based on roving creel surveys (on‐site angler surveys during which anglers' harvests are examined by the survey clerk). The study aimed to assess the biological impacts of this leisure activity on coastal fish stocks and the potential risks arising from the use of exotic baits.

Recreational shore fishers employ seven different fishing techniques, of which the bottom fishing rod (a fishing rod whose hooks, together with the bait, lie on the bottom or near it by means of a heavy weight) is by far the most widely used method (nearly 90% of observations). In total, 25 fish species were identified in the catch from the bottom fishing rod.

The estimated annual shore fishing catches (c.3 tons) are much lower than those obtained by recreational boat and spear fishing (c.20 tons each), and those from commercial (artisanal) fishing (c.50 tons). The weighted mean vulnerability index and trophic level values in the catch from the bottom fishing rod are 52.2 and 4.03, respectively.

A minimum of 43% of the baits used by the shore anglers were live, non‐native species (mostly polychaetes).

Overall, results highlight the impact of shore angling on coastal fish communities of a protected area and the increasing environmental risks arising from the use of exotic marine baits, which constitute a potential and unregulated vector of introduction of non‐native species in the Mediterranean. Copyright © 2011 John Wiley & Sons, Ltd.