bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambient glucose levels qualify the potency of insulin myogenic actions by regulating SIRT1 and FoxO3a in C2C12 myocytes
Authors: Nedachi Taku , Kadotani Akito , Ariga Miyako , Katagiri Hideki , Kanzaki Makoto
Published: January 2008

Nutrition availability is one of the major environmental signals influencing cell fate, such as proliferation, differentiation, and apoptosis, often functioning in concert with other humoral factors, including insulin. Herein, we show that low-serum-induced differentiation of C2C12 myocytes is significantly hampered under low glucose (LG; 5 mM) compared with high glucose (HG; 22.5 mM) conditions, concurrently with nuclear accumulation of SIRT1, an NAD+-dependent deacetylase, and FoxO3a, both of which are implicated in the negative regulation of myogenesis. Intriguingly, insulin appears to exert opposite actions, depending on glucose availability, with regard to the regulation of SIRT1 and FoxO3a abundance, which apparently contributes to modulating the potency of insulin's myogenic action. Namely, insulin exerts a potent myogenic effect in the presence of sufficient glucose, whereas insulin is unable to exert its myogenic action under LG conditions, since insulin evokes massive upregulation of both SIRT1 and FoxO3a in the absence of sufficient ambient glucose. In addition, the hampered differentiation state under LG is significantly restored by sirtinol, a SIRT1 inhibitor, whereas insulin abolished this sirtinol-dependent restoration, indicating that insulin can function as a negative as well as a positive myogenic factor depending on glucose availability. Taken together, our data reveal the importance of ambient glucose levels in the regulation of myogenesis and also in the determination of insulin's myogenic potency, which is achieved, at least in part, through regulation of the cellular contents and localization of SIRT1 and FoxO3a in differentiating C2C12 myocytes.
Technetium 99m–Labeled Annexin V Scintigraphy of Platelet Activation in Vegetations of Experimental Endocarditis
Authors: Rouzet Francois , Hernandez Miguel Dominguez , Hervatin Florence , Sarda-Mantel Laure , Lefort Agnes , Duval Xavier , Louedec Liliane , Fantin Bruno , Le Guludec Dominique , Michel Jean-Baptiste
Published: January 2008

Background—

The pathophysiology of infective endocarditis involves a pathogen/host tissue interaction, leading to formation of infected thrombotic vegetations. Annexin V is a ligand of phosphatidylserines exposed by activated platelets and apoptotic cells. Because vegetations are platelet-fibrin clots in which platelet proaggregant activity is enhanced by bacterial colonization, we investigated the ability of annexin V labeled with technetium Tc 99m (
99m
Tc-ANX) to provide functional imaging of these vegetations in experimental models of infective endocarditis. This ability was assessed in rabbits and rats because of the different interest of these 2 species in preclinical analysis.

Methods and Results—

Nonbacterial thrombotic endocarditis was induced with the use of a catheter left indwelling through the aortic or tricuspid valve, and animals were injected with either a bacterial inoculum or saline. Scintigraphic investigations were performed 5 days later and showed a higher
99m
Tc-ANX uptake by vegetations in infected versus noninfected animals (ratio, 1.3 for in vivo acquisitions and 2 for autoradiography;
P
<0.0001 for all), whereas no significant uptake was present in controls. Right-sided endocarditis was associated with pulmonary uptake foci corresponding to emboli. Histological analysis of vegetations showed a specific uptake of
99m
Tc-ANX at the interface between circulating blood and vegetation. In parallel, underlying myocardial tissue showed myocyte apoptosis and mucoid degeneration, without extracellular matrix degradation at this stage.

Conclusions—

99m
Tc-ANX is suitable for functional imaging of platelet-fibrin vegetations in endocarditis, as well as embolic events.
99m
Tc-ANX uptake reflects mainly platelet activation in the luminal layer of vegetations. This uptake is enhanced by bacterial colonization.
Identification of Target Domains of the Cardiac Ryanodine Receptor to Correct Channel Disorder in Failing Hearts
Authors: Yamamoto Takeshi , Yano Masafumi , Xu XiaoJuan , Uchinoumi Hitoshi , Tateishi Hiroki , Mochizuki Mamoru , Oda Tetsuro , Kobayashi Shigeki , Ikemoto Noriaki , Matsuzaki Masunori
Published: January 2008

Background—

We previously demonstrated that defective interdomain interaction between N-terminal (0 to 600) and central regions (2000 to 2500) of ryanodine receptor 2 (RyR2) induces Ca
2+
leak in failing hearts and that K201 (JTV519) inhibits the Ca
2+
leak by correcting the defective interdomain interaction. In the present report, we identified the K201-binding domain and characterized the role of this novel domain in the regulation of the RyR2 channel.

Methods and Results—

An assay using a quartz-crystal microbalance technique (a very sensitive mass-measuring technique) revealed that K201 specifically bound to recombinant RyR2 fragments 1741 to 2270 and 1981 to 2520 but not to other RyR2 fragments from the 1 to 2750 region (1 to 610, 494 to 1000, 741 to 1260, 985 to 1503, 1245 to 1768, 2234 to 2750). By further analysis of the fragment
1741–2270
, K201 was found to specifically bind to its subfragment
2114–2149
. With the use of the peptide matching this subfragment (DP
2114–2149
) as a carrier, the RyR2 was fluorescently labeled with methylcoumarin acetate (MCA) in a site-directed manner. After tryptic digestion, the major MCA-labeled fragment of RyR2 (155 kDa) was detected by an antibody raised against the central region (Ab
2132
). Moreover, of several recombinant RyR2 fragments, only fragment
2234–2750
was specifically MCA labeled; this suggests that the K201-binding domain
2114–2149
binds with domain
2234–2750
. Addition of DP
2114–2149
to the MCA-labeled sarcoplasmic reticulum interfered with the interaction between domain
2114–2149
and domain
2234–2750
, causing domain unzipping, as evidenced by an increased accessibility of the bound MCA to a large-size fluorescence quencher. In failing cardiomyocytes, the frequency of spontaneous Ca
2+
spark was markedly increased compared with normal cardiomyocytes, whereas incorporation of DP
2114–2149
markedly decreased the frequency of spontaneous Ca
2+
spark.

Conclusions—

We first identified the K201-binding site as domain
2114–2149
of RyR2. Interruption of the interdomain interaction between the domain
2114–2149
and central domain
2234–2750
seems to mediate stabilization of RyR2 in failing hearts, which may lead to a novel therapeutic strategy against heart failure and perhaps lethal arrhythmia.
Symptomatic Peripheral Arterial Disease in Women
Authors: Pradhan Aruna D. , Shrivastava Sanjay , Cook Nancy R. , Rifai Nader , Creager Mark A. , Ridker Paul M
Published: January 2008

Background—

Most investigations of novel biomarkers for prediction of cardiovascular disease pertain to coronary artery disease. Few large-scale prospective studies have critically assessed plasma-based factors as predictors of peripheral arterial disease (PAD), and comparative data between individual biomarkers and lipid levels are sparse, especially among women.

Methods and Results—

We evaluated the relationship between baseline levels of several novel biomarkers and confirmed incident symptomatic PAD (n=100) in a prospective cohort study (median follow-up, 12.3 years) involving 27 935 US female health professionals ≥45 years of age without diagnosed vascular disease at baseline. Biomarkers assessed were high-sensitivity C-reactive protein, fibrinogen, soluble intercellular adhesion molecule-1 (sICAM-1), homocysteine, lipoprotein(a), hemoglobin A
1c
, creatinine, and conventional lipid levels. In univariate analyses, levels of high-sensitivity C-reactive protein, fibrinogen, sICAM-1, homocysteine, lipoprotein(a), creatinine clearance, high-density lipoprotein cholesterol (HDL-C), non–HDL-C, and the ratio of total cholesterol to HDL-C (TC:HDL-C) were significantly related to PAD (all
P
<0.05). However, after multivariable adjustment, risk associations were significant only for high-sensitivity C-reactive protein (adjusted hazard ratio [HR] extreme tertiles, 2.1; 95% confidence interval, 1.2 to 3.7), sICAM-1 (adjusted HR, 4.0; 95% confidence interval, 1.9 to 8.6), HDL-C (adjusted HR, 0.4; 95% confidence interval, 0.3 to 0.8), and TC:HDL-C (adjusted HR, 2.2; 95% confidence interval, 1.2 to 3.9). In a model simultaneously controlling for traditional risk factors plus these significant biomarkers, sICAM-1 remained independently predictive of PAD (adjusted HR in each tertile, 1.0 [reference], 2.3, and 3.5).

Conclusions—

Among a broad range of biomarkers of cardiovascular risk, only 4 factors, sICAM-1, high-sensitivity C-reactive protein, HDL-C, and TC:HDL-C, were significantly associated with incident symptomatic PAD in women. Findings pertaining to novel biomarkers provide clinical confirmation of a prominent role of endothelial activation and leukocyte recruitment in lower-extremity arterial disease.
Remodeling Phenotype of Human Subcutaneous Adipose Tissue Macrophages
Authors: Bourlier V. , Zakaroff-Girard A. , Miranville A. , De Barros S. , Maumus M. , Sengenes C. , Galitzky J. , Lafontan M. , Karpe F. , Frayn K.N. , Bouloumié A.
Published: January 2008

Background—

Adipose tissue macrophages (ATMs) have become a focus of attention recently because they have been shown to accumulate with an increase in fat mass and to be involved in the genesis of insulin resistance in obese mice. However, the phenotype and functions of human ATMs are still to be defined.

Methods and Results—

The present study, performed on human subcutaneous AT, showed that ATMs from lean to overweight individuals are composed of distinct macrophage subsets based on the expression of several cell surface markers: CD45, CD14, CD31, CD44, HLA-DR, CD206, and CD16, as assessed by flow cytometry. ATMs isolated by an immunoselection protocol showed a mixed expression of proinflammatory (tumor necrosis factor-α, interleukin-6 [IL-6], IL-23, monocyte chemoattractant protein-1, IL-8, cyclooxygenase-2) and antiinflammatory (IL-10, transforming growth factor-β, alternative macrophage activation–associated cc chemokine-1, cyclooxygenase-1) factors. Fat mass enlargement is associated with accumulation of the CD206
+
/CD16
−
macrophage subset that exhibits an M2 remodeling phenotype characterized by decreased expression of proinflammatory IL-8 and cyclooxygenase-2 and increased expression of lymphatic vessel endothelial hyaluronan receptor-1. ATMs specifically produced and released matrix metalloproteinase-9 compared with adipocytes and capillary endothelial cells, and secretion of matrix metalloproteinase-9 from human AT in vivo, assessed by arteriovenous difference measurement, was correlated with body mass index. Finally, ATMs exerted a marked proangiogenic effect on AT-derived endothelial and progenitor cells.

Conclusions—

The present results showed that the ATMs that accumulate with fat mass development exhibit a particular M2 remodeling phenotype. ATMs may be active players in the process of AT development through the extension of the capillary network and in the genesis of obesity-associated cardiovascular pathologies.
Does Aldosterone Upregulate the Brain Renin-Angiotensin System in Rats With Heart Failure?
Authors: Yu Yang , Wei Shun-Guang , Zhang Zhi-Hua , Gomez-Sanchez Elise , Weiss Robert M. , Felder Robert B.
Published: January 2008

The brain renin-angiotensin system (RAS) contributes to increased sympathetic drive in heart failure (HF). The factors upregulating the brain RAS in HF remain unknown. We hypothesized that aldosterone (ALDO), a downstream product of the systemic RAS that crosses the blood-brain barrier, signals the brain to increase RAS activity in HF. We examined the relationship between circulating and brain ALDO in normal intact rats, in adrenalectomized rats receiving subcutaneous infusions of ALDO, and in rats with ischemia-induced HF and sham-operated controls. Brain ALDO levels were proportional to plasma ALDO levels across the spectrum of rats studied. Compared with sham-operated controls rats, HF rats had higher plasma and hypothalamic tissue levels of ALDO. HF rats also had higher expression of mRNA and protein for angiotensin-converting enzyme and angiotensin type 1 receptors in the hypothalamus, increased reduced nicotinamide-adenine dinucleotide phosphate oxidase activity and superoxide generation in the paraventricular nucleus of the hypothalamus, increased excitation of paraventricular nucleus neurons, and increased plasma norepinephrine. HF rats treated for 4 weeks with intracerebroventricular RU28318 (1 μg/h), a selective mineralocorticoid receptor antagonist, had less hypothalamic angiotensin-converting enzyme and angiotensin type 1 receptor mRNA and protein, less reduced nicotinamide-adenine dinucleotide phosphate–induced superoxide in the paraventricular nucleus, fewer excited paraventricular nucleus neurons, and lower plasma norepinephrine. RU28318 had no effect on plasma ALDO or on angiotensin-converting enzyme or angiotensin type 1 receptor expression in brain cortex. The data demonstrate that ALDO of adrenal origin enters the hypothalamus in direct proportion to plasma levels and suggest that ALDO contributes to the upregulation of hypothalamic RAS activity and sympathetic drive in heart failure.
Description of Diplogastrellus gracilis (Bütschli, 1876) Paramonov, 1952, D. sikorai sp. n. and Fictor composticola sp. n. (Nematoda: Diplogastrina) from India
Authors: Tahseen Qudsia , Khan Rahmat , Sultana Razia , Bajaj Harish
Published: January 2008

Two new diplogastrid species, Diplogastrellus sikorai sp. n. and Fictor composticola sp. n., are described and illustrated. Another species, D. gracilis, is reported for the first time from India and is redescribed with an emended diagnosis and SEM details. Diplogastrellus sikorai sp. n. is characterised by relatively small-sized body (female: L = 0.49-0.65 mm, a = 24-30, b = 4.9-6.3, c = 2.4-2.8), with a prominent, upright, dagger-like dorsal tooth and well developed subventral ridge; pore-like vulva, large post-uterine sac; ventrally arcuate spicules with rounded capitula and rosethorn-shaped gubernaculum with proximal spur and lateral sleeves around the spicules. Fictor composticola sp. n. is characterised by medium-sized body, eight cheilostomal plates with 18-22 cheilostomal filaments; gymnostom and stegostom with serrated anterior margins; dorsal and right subventral stegostomal walls each bearing a more or less equal tooth; left subventral stegostomal wall with two adjacent serrated plates; males with weakly cephalated, slender, ventrally arcuate spicules; wedge-shaped gubernaculum with tapering proximal end and lateral sleeves surrounding the distal ends of the spicules; and nine pairs of caudal papillae.
Preocupación ambiental y bienestar humano. Contribuciones desde la Psicología Ambiental
Authors: Corraliza José-Antonio , Berenguer Jaime , Martín Rocío
Published: January 2008

En este artículo se presentan una serie de contribuciones desde la Psicología Ambiental. Se describe la Psicología Ambiental como un campo dinámico que en las últimas dos décadas ha vivido un cambio de acento desde el interés por la investigación de los aspectos espaciales y sociofísicos, incorporando la investigación sobre las dimensiones psicosociales de la crisis ecológica. Se presentan diferentes contribuciones desde la Psicología Ambiental que abordan dos aspectos complementarios: la preocupación ambiental y el bienestar humano en los escenarios urbanos.
¿Qué motiva la valoración del medio ambiente? La relación del ecocentrismo y del antropocentrismo con la motivación interna y externa
Authors: Suárez Ernesto , Salazar María-Esther , Hernández Bernardo , Martín Ana-María
Published: January 2008

Antropocentrismo y ecocentrismo constituyen los dos ejes esenciales sobre los que se sostienen las actitudes ambientales y, en general, los juicios valorativos sobre el medio natural. No obstante, aunque inicialmente se plantea que se trata de dimensiones independientes entre sí, al revisar los trabajos que han analizado la relación entre ambos conceptos se pone de manifiesto que nada definitivo puede decirse sobre el grado de independencia existente entre ambos factores. La investigación que aquí se presenta tiene como objetivo analizar la relación entre los factores de ecocentrismo y antropocentrismo atendiendo a la base motivacional sobre la que se sustentan. Así, el ecocentrismo estaría intrínsecamente motivado y persigue satisfacer necesidades psicológicas de relación, autonomía y competencia, mientras que el antropocentrismo estaría motivado por la necesidad de ajuste social aunque no como mera respuesta de conformidad. Los resultados obtenidos en esta investigación confirman la ausencia de correlación entre los factores actitudinales de antropocentrismo y ecocentrismo, que se interpreta a la luz de la ausencia de correlación entre las medidas motivacionales. También se ha puesto de manifiesto una relación positiva y significativa entre el factor de ecocentrismo y la motivación interna, así como entre antropocentrismo y motivación externa.
Unfiltering of the Geostationary Earth Radiation Budget (GERB) Data. Part I: Shortwave Radiation
Authors: Clerbaux N. , Dewitte S. , Bertrand C. , Caprion D. , De Paepe B. , Gonzalez L. , Ipe A. , Russell J. E. , Brindley H.
Published: January 2008

The method used to estimate the unfiltered shortwave broadband radiance from the filtered radiances measured by the Geostationary Earth Radiation Budget (GERB) instrument is presented. This unfiltering method is used to generate the first released edition of the GERB-2 dataset. The method involves a set of regressions between the unfiltering factor (i.e., the ratio of the unfiltered and filtered broadband radiances) and the narrowband observations of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument. The regressions are theoretically derived from a large database of simulated spectral radiance curves obtained by radiative transfer computations. The generation of the database is fully described.

Different sources of error that may affect the GERB unfiltering have been identified and the associated error magnitudes are assessed on this database. For most of the earth–atmosphere conditions, the error introduced during the unfiltering process is below 1%. In some conditions (e.g., low sun elevation above the horizon) the error can present a higher relative value, but the absolute error value remains well under the accuracy goal of 1% of the full instrument scale (2.4 W m−2 sr−1).

To increase the confidence level, the edition 1 unfiltered radiances of GERB-2 are validated by cross comparison with collocated and coangular Clouds and the Earth’s Radiant Energy System (CERES) observations for different scene types. In addition to an overall offset between the two instruments, the intercomparisons indicate a scene-type dependency up to 4% in unfiltered radiance. Further studies are required to confirm the cause, but an insufficiently accurate characterization of the shortwave spectral response of the GERB instrument in the visible part of the spectrum is one area under further investigation.
Aerosol Impacts on the Diurnal Cycle of Marine Stratocumulus
Authors: Sandu Irina , Brenguier Jean-Louis , Geoffroy Olivier , Thouron Odile , Masson Valery
Published: January 2008

Recent large-eddy simulation (LES) studies of the impact of aerosol on the dynamics of nocturnal marine stratocumulus revealed that, depending on the large-scale forcings, an aerosol-induced increase of the droplet concentration can lead to either an increase or a decrease of the liquid water path, hence contrasting with the cloud thickening that is expected from a reduction of the precipitation efficiency. In this study, the aerosol impacts on cloud microphysics are examined in the context of the boundary-layer diurnal cycle using 36-h LES simulations of pristine and polluted clouds. These simulations corroborate previous findings that during nighttime aerosol-induced liquid water path changes are sensitive to the large-scale forcings via enhancement of cloud-top entrainment such that, ultimately, the liquid water path may be reduced when the free-tropospheric-entrained air is drier. During the day, however, enhanced entrainment, inhibition of drizzle evaporation below cloud base, and reduced sensible heat flux from the surface lead to a more pronounced decoupling of the boundary layer, which significantly amplifies the liquid water path reduction of the polluted clouds. At night the sign of the liquid water path difference between pristine and polluted clouds depends upon large-scale forcings, while during the day the liquid water path of polluted clouds is always smaller than the one of the pristine clouds. Suggestions are made on how observational studies could be designed for validation of these simulations.
A Baroclinic Laminar State for Rotating Stratified Flows
Authors: Sun Che
Published: January 2008

A baroclinic laminar model is developed as the late-time equilibrium state in the free decay of rotating stratified turbulence under low-Froude-number scaling. Vertical motions are suppressed by stratification and ambient rotation, and in the laminar end state the flow assumes a quasi-two-dimensional form. Geometric analyses of this nonlinear conservative model reveal an f-plane baroclinic topology characterized by vertical alignment, vanishing nonlinearity, and the complete absence of helicity. Equivalent-barotropic flow is the only nonunique baroclinic solution, and its horizontal topology is restricted to a unidirectional jet and a circular vortex. Such a depleted geometry results from the constraint of basic equations where density is advected as an active scalar. It provides a baroclinic mechanism for the formation of coherent structures in geophysical flows.
Consequences of Considering Carbon–Nitrogen Interactions on the Feedbacks between Climate and the Terrestrial Carbon Cycle
Authors: Sokolov Andrei P. , Kicklighter David W. , Melillo Jerry M. , Felzer Benjamin S. , Schlosser C. Adam , Cronin Timothy W.
Published: January 2008

The impact of carbon–nitrogen dynamics in terrestrial ecosystems on the interaction between the carbon cycle and climate is studied using an earth system model of intermediate complexity, the MIT Integrated Global Systems Model (IGSM). Numerical simulations were carried out with two versions of the IGSM’s Terrestrial Ecosystems Model, one with and one without carbon–nitrogen dynamics.

Simulations show that consideration of carbon–nitrogen interactions not only limits the effect of CO2 fertilization but also changes the sign of the feedback between the climate and terrestrial carbon cycle. In the absence of carbon–nitrogen interactions, surface warming significantly reduces carbon sequestration in both vegetation and soil by increasing respiration and decomposition (a positive feedback). If plant carbon uptake, however, is assumed to be nitrogen limited, an increase in decomposition leads to an increase in nitrogen availability stimulating plant growth. The resulting increase in carbon uptake by vegetation exceeds carbon loss from the soil, leading to enhanced carbon sequestration (a negative feedback). Under very strong surface warming, however, terrestrial ecosystems become a carbon source whether or not carbon–nitrogen interactions are considered.

Overall, for small or moderate increases in surface temperatures, consideration of carbon–nitrogen interactions result in a larger increase in atmospheric CO2 concentration in the simulations with prescribed carbon emissions. This suggests that models that ignore terrestrial carbon–nitrogen dynamics will underestimate reductions in carbon emissions required to achieve atmospheric CO2 stabilization at a given level. At the same time, compensation between climate-related changes in the terrestrial and oceanic carbon uptakes significantly reduces uncertainty in projected CO2 concentration.
Ocean Forcing to Changes in Global Monsoon Precipitation over the Recent Half-Century
Authors: Zhou Tianjun , Yu Rucong , Li Hongmei , Wang Bin
Published: January 2008

Previous examination of changes in global monsoon precipitation over land reveals an overall weakening over the recent half-century (1950–2000). The present study suggests that this significant change in global land monsoon precipitation is deducible from the atmosphere’s response to the observed SST variations. When forced by historical sea surface temperatures covering the same period, the ensemble simulation with the NCAR Community Atmosphere Model, version 2 (CAM2) model successfully reproduced the weakening tendency of global land monsoon precipitation. This decreasing tendency was mainly caused by the warming trend over the central-eastern Pacific and the western tropical Indian Ocean. At the interannual time scale, the global land monsoon precipitation is closely correlated with ENSO. The simulated interannual variation of the global land monsoon index matches well with the observation, indicating that most monsoon precipitation variations arise from the ocean forcing. There are uncertainties between the GPCP and the CMAP data in describing the evolution of global ocean monsoon precipitation. There is very little correspondence between the simulated and the observed global monsoon index over the ocean area. Uncertainties in the satellite data and model deficiencies in describing the ocean monsoon domain are partly to blame. Among the components of global monsoon systems, the Asian–Australian monsoon system has the lowest reproducibility with prescribed SST forcing due to the neglect of air–sea feedback.
Mesoscale Eddies in the Labrador Sea and Their Contribution to Convection and Restratification
Authors: Chanut Jérôme , Barnier Bernard , Large William , Debreu Laurent , Penduff Thierry , Molines Jean Marc , Mathiot Pierre
Published: January 2008

The cycle of open ocean deep convection in the Labrador Sea is studied in a realistic, high-resolution (4 km) regional model, embedded in a coarser (⅓°) North Atlantic setup. This configuration allows the simultaneous generation and evolution of three different eddy types that are distinguished by their source region, generation mechanism, and dynamics. Very energetic Irminger Rings (IRs) are generated by barotropic instability of the West Greenland and Irminger Currents (WGC/IC) off Cape Desolation and are characterized by a warm, salty subsurface core. They densely populate the basin north of 58°N, where their eddy kinetic energy (EKE) matches the signal observed by satellite altimetry. Significant levels of EKE are also found offshore of the West Greenland and Labrador coasts, where boundary current eddies (BCEs) are spawned by weakly energetic instabilities all along the boundary current system (BCS). Baroclinic instability of the steep isopycnal slopes that result from a deep convective overturning event produces convective eddies (CEs) of 20–30 km in diameter, as observed and produced in more idealized models, with a distinct seasonal cycle of EKE peaking in April. Sensitivity experiments show that each of these eddy types plays a distinct role in the heat budget of the central Labrador Sea, hence in the convection cycle.

As observed in nature, deep convective mixing is limited to areas where adequate preconditioning can occur, that is, to a small region in the southwestern quadrant of the central basin. To the east, west, and south, BCEs flux heat from the BCS at a rate sufficient to counteract air–sea buoyancy loss. To the north, this eddy flux alone is not enough, but when combined with the effects of Irminger Rings, preconditioning is effectively inhibited here too. Following a deep convective mixing event, the homogeneous convection patch reaches as deep as 2000 m and a horizontal scale on the order of 200 km, as has been observed. Both CEs and BCEs are found to play critical roles in the lateral mixing phase, when the patch restratifies and transforms into Labrador Sea Water (LSW). BCEs extract the necessary heat from the BCS and transport it to the deep convection site, where it fluxed into convective patches by CEs during the initial phase. Later in the phase, BCE heat flux maintains and strengthens the restratification throughout the column, while solar heating establishes a near-surface seasonal stratification. In contrast, IRs appear to rarely enter the deep convection region. However, by virtue of their control on the surface area preconditioned for deep convection and the interannual variability of the associated barotropic instability, they could have an important role in the variability of LSW.
Unfiltering of the Geostationary Earth Radiation Budget (GERB) Data. Part II: Longwave Radiation
Authors: Clerbaux N. , Dewitte S. , Bertrand C. , Caprion D. , De Paepe B. , Gonzalez L. , Ipe A. , Russell J. E.
Published: January 2008

The method used to estimate the unfiltered longwave broadband radiance from the filtered radiances measured by the Geostationary Earth Radiation Budget (GERB) instrument is presented. This unfiltering method is used to generate the first released edition of the GERB-2 dataset. This method involves a set of regressions between the unfiltering factor (i.e., the ratio of the unfiltered and filtered broadband radiances) and the narrowband observations of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument. The regressions are theoretically derived from a large database of simulated spectral radiance curves obtained by radiative transfer computations. The generation of this database is fully described.

Different sources of error that may affect the GERB unfiltering have been identified and the associated error magnitudes are assessed on the database. For most of the earth–atmosphere conditions, the error introduced during the unfiltering processes is well under 0.5% (RMS error of about 0.1%). For more confidence, the unfiltered radiances of GERB-2 are validated by cross comparison with collocated and coangular Clouds and the Earth’s Radiant Energy System (CERES) observations. The agreement between the unfiltered radiances is within the science goals (1% accuracy for GERB and 0.5% for CERES) for the Flight Model 2 (FM2). For the CERES Flight Model 3 (FM3) instrument, an overall difference of 1.8% is observed. The intercomparisons indicate some scene-type dependency, which is due to the unfiltering for the cloudy scenes. This should be corrected for subsequent editions of the database.
Vortex Lines within Low-Level Mesocyclones Obtained from Pseudo-Dual-Doppler Radar Observations
Authors: Markowski Paul , Richardson Yvette , Rasmussen Erik , Straka Jerry , Davies-Jones Robert , Trapp Robert J.
Published: January 2008

Vortex lines passing through the low-level mesocyclone regions of six supercell thunderstorms (three nontornadic, three tornadic) are computed from pseudo-dual-Doppler airborne radar observations obtained during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX). In every case, at least some of the vortex lines emanating from the low-level mesocyclones form arches, that is, they extend vertically from the cyclonic vorticity maximum, then turn horizontally (usually toward the south or southwest) and descend into a broad region of anticyclonic vertical vorticity. This region of anticyclonic vorticity is the same one that has been observed almost invariably to accompany the cyclonic vorticity maximum associated with the low-level mesocyclone; the vorticity couplet straddles the hook echo of the supercell thunderstorm. The arching of the vortex lines and the orientation of the vorticity vector along the vortex line arches, compared to the orientation of the ambient (barotropic) vorticity, are strongly suggestive of baroclinic vorticity generation within the hook echo and associated rear-flank downdraft region of the supercells, and subsequent lifting of the baroclinically altered/generated vortex lines by an updraft. Discussion on the generality of these findings, possible implications for tornadogenesis, and the similarity of the observed vortex lines to vortex lines in larger-scale convective systems are included as well.
Searching for Kinship
Authors: Smith Hilary
Published: January 2008

Drawing on in-depth interviews with 30 homeless youth, this study depicts a unique aspect of homeless youth street culture—the formation of “street families.” This article examines youth's motivations for creating street families, their organization and maintenance, and the role gender plays in adopting familial identities. Although many homeless adolescents come from dysfunctional families, street family members often recreate traditional family roles. Membership often mitigates the demands of street life, yet intragroup violence/victimization is common. The findings highlight the unique nature of street families and implications for research, policy, and practice, including the need for involving peers in intervention efforts.
Psychosocial Status of Homeless Children and Youth in Family Supportive Housing
Authors: Gewirtz Abigail , Hart-Shegos Ellen , Medhanie Amanuel
Published: January 2008

Shelter-based studies have documented risks to homeless children's development, but scant information is available about children residing in family supportive housing, a key strategy for preventing long-term homelessness. This study assessed the psychosocial and health status of 454 formerly homeless children living with their families in 17 supportive housing communities. Findings indicated that children had good access to physical health care. However, children faced significant psychosocial risks and manifested behavioral, emotional, and school challenges. Housing agencies lacked infrastructure or expertise in children's mental health. The authors propose that supportive housing provides a valuable but hitherto underused opportunity to support children's psychosocial functioning.
Outsourcing and transborder data flows: the challenge of protecting personal information under the shadow of the USA Patriot Act
Authors: Stefanick Lorna
Published: January 2008

Governments are increasingly outsourcing service provision to private contractors in an effort to realize cost efficiencies. The passage of the USA Patriot Act, however, has caused concern that government outsourcing of data management to US-based companies could result in the violation of fundamental civil liberties. What follows is a case study of a Canadian provincial government's plan to out-source the administration of a public health insurance and drug plan to a Canadian subsidiary of an American company. Within the context of the larger international concern about the reach of the USA Patriot Act, the article discusses the Canadian response to the fear that outsourcing will compromise the security of personal health information. It concludes that while different privacy protection experts worldwide have drawn different conclusions as to the implications of the USA Patriot Act, the ability of governments to protect the large amounts of data that are entrusted to them is becoming increasingly difficult.

Points for practitioners

Globalization and electronic communication not only challenge the sovereignty of the nation-state, but complicate the environment that both companies and governments `do business' in. This is particularly true given the swift passage of the USA Patriot Act 45 days after the September 11 attacks on New York's twin towers. This study of public sector data management outsourcing demonstrates that accountability, transparency and control over governments and their agents must not be compromised in the face of high profile demands to enhance national security or due to more mundane pressure to increase administrative efficiency.
Citizen or customer? Complaints handling in the public sector
Authors: Brewer Brian
Published: January 2008

Ensuring that public service complaints are handled effectively and rights of redress upheld is an integral feature of good governance and effective service delivery. A review of the academic literature and a number of key government reports reveals what citizen complaint and redress systems exist currently, how they can be designed and enabled to operate with the greatest positive impact, and why they are important in holding public officials accountable for the use of discretionary decision-making authority. With the development of new public management (NPM) and public sector reforms in many jurisdictions, a consumerist model for handling complaints has come increasingly to the fore. When combined with the traditional citizenship perspective, this would appear to have considerable potential for improving complaints handling and redress. However, the consumerist model's narrow focus on customer satisfaction and the risk of weakening citizenship values such as fairness and social justice suggest a cautious approach may be best. Public sector managers and professionals need an awareness of how public reform strategies oriented exclusively towards a strengthened consumer role do risk undermining important aspects of the complaints handling and redress strategies embedded in the `rule of law' and `due process' features of citizen-oriented public administration. Accountability may be weakened when service recipients are defined less in terms of their citizenship and more on the basis of a narrowly defined status as a marketplace consumer. This is a key implication of current trends by governments to rely increasingly on privatization, contracting-out and public—private partnerships to deliver services.

Points for practitioners

How well service complaints are handled is a key determinant of quality in the public services at both systemic and service-recipient levels. Procedures that are easily accessible, simple to invoke and operate, transparent, ensure stakeholders are kept informed, and sensitive to different social groups help build confidence in complaints handling and redress processes. However, as more public services are delivered by quasi-public and private organizations using contracting and subcontracting arrangements, the challenge facing practitioners is how to ensure that citizen-centric values are maintained even as external review agencies like the Ombudsman and traditional accountability promoting procedures are replaced by narrower consumerist-oriented approaches.
Transforming service to Canadians: the Service Canada model
Authors: Flumian Maryantonett , Coe Amanda , Kernaghan Kenneth
Published: January 2008

Over the past decade, the pursuit of citizen-centred service, combined with rapid advances in information and communication technologies, has stimulated innovative approaches to the organizational design of governments' service delivery systems. Service delivery organizations in Canada and elsewhere have taken a variety of organizational forms, thereby providing a range of models for adoption or adaptation. Service Canada offers Canadians a new model for the delivery of government services. It is a one-stop, multi-channel and multi-jurisdictional initiative that is dedicated to delivering seamless citizen-centred service. It brings together a wide range of government programmes and services from across federal departments and other levels of government to provide citizens with integrated, easy-to-access, personalized service. This article assesses the possibilities that the Service Canada model presents for service transformation through integrated service delivery (ISD) and discusses political, structural, operational, managerial and cultural barriers to its implementation.

Points for practitioners

Successful ISD initiatives can take a variety of organizational forms with an array of governance arrangements. While some of the ISD challenges are not faced by all countries, many of the challenges (e.g. privacy and security issues) are of a generic nature. Many of the solutions to ISD challenges are also of general application, including those utilized by Service Canada — the innovative use of partnerships, adequate funding, guaranteed privacy and security and effective human resource management. Note also that successful service transformation requires the creation of a culture of service excellence among employees, the demonstration of frequent and tangible results, and understanding that leadership in service integration requires a capacity for adapting to an ambiguous and ever-changing environment.
Administrative reform in Portugal: problems and prospects
Authors: Rocha J.A. Oliveira , Ferraz Esteves de Araujo Joaquim Filipe
Published: January 2008

Administrative reform has been an important issue for several decades in Western countries. Like other Western countries, Portugal developed an increasing interest in administrative reform. This article is a contemporary analysis of Portuguese administrative reform. It introduces the Portuguese system and outlines its major features. Briefly stated, the decrease in State expenditure is represented by the proletarization of the middle class that lives off the State; there is an increase in party clientelism, since the old systems based on legal statutes are subject to flexibilization; and, finally, privatizations increase economic monopolies because the regulatory agencies do not work. This means that if this therapy was to be applied to small countries like Portugal, it could have serious consequences for Europe.

Points for practitioners

The article reflects the consequences of New Public Management when applied to a traditional bureaucracy. The introduction of administrative reform is more difficult in legal systems such as Portugal. So practitioners and politicians can learn from this case study when dealing with reforms in similar systems.
Reforming local public administration in Romania: trends and obstacles
Authors: Dragoş Dacian C. , Neamţu Bogdana
Published: January 2008

This article endeavors to diagnose and critically assess some of the challenges Romanian public administration is confronted with and to discuss some of the reform efforts that have been made in order to cope with these challenges. The concept of administrative capacity is central to this analysis — the authors examine the practical implications of this concept and try to assess what could be done in order to increase the administrative capacity of local public administration and to complete the decentralization process. From a methodological standpoint, the article employs qualitative analysis. Secondary data analysis and document analysis (scientific papers and official documents such as laws, reports issued by the EU institutions) were used in order to justify some of the comments and assumptions made throughout the article.

Points for practitioners

The article highlights several of the reform efforts in the field of public administration undertaken recently by Romania. It points out that the process of decentralization is closely intertwined with the development of the administrative capacity of the territorial units. The authors argue in favor of seeking a balance between focus on internal reform and changing the relations between the public administration and society. One of the main conclusions is that although Romania has improved the legislation in the field of decentralization and local autonomy, there are still steps that need to be taken towards better implementation.
Examining the Antecedents of Brand Loyalty from an Investment Model Perspective
Authors: Li Xiang (Robert) , Petrick James F.
Published: January 2008

The primary purpose of this study is to theoretically identify the key determinants of brand loyalty. Based on the investment model in social psychology, this article suggests that customers'attitudinal loyalty to a brand is weakened by the quality of alternative options but strengthened by their satisfaction with, and investment in, the brand. An online panel survey was conducted, and the data supported all hypothesized relationships. Collectively, satisfaction, quality of alternatives, and investment accounted for more than 74% of the variance in attitudinal loyalty. The findings suggest that the investment model may lend a theoretical foundation to the explanation of tourists'brand loyalty formation.
Factors That Contribute to Levels of Independent Activity Functioning Among a Group of Navajo Elders
Authors: Fitzpatrick Tanya R. , Alemán Sara , Van Tran Thanh
Published: January 2008

The purpose of this study was to examine factors that contribute to levels of independent activity functioning among a group of elder Navajos. Data were collected from a sample of Navajo elders from Tuba City, Arizona, and a health assessment survey was administered. Multiple regression analysis was used to examine the effects of social support and demographic factors on levels of independent activity functioning, such as bathing, toileting, dressing, eating, walking, and getting in and out of bed. The results indicated that assistive devices, marital status, the frequency of visits to Tuba City, and visits to the elders significantly affected independent activity functioning. Although other factors of social support were not significant, it appeared that visiting Tuba City and visits to the elders in their homes were important factors in maintaining higher levels of independent activity functioning among elder Navajos. Implications for practice, policy, and future research are discussed.
Self-Reported Injury History and Lower Limb Function as Risk Factors for Injuries in Female Youth Soccer
Authors: Steffen Kathrin , Myklebust Grethe , Andersen Thor Einar , Holme Ingar , Bahr Roald
Published: January 2008

Background

Identifying and understanding injury risk factors are necessary to develop and target measures to prevent injuries. Because youth teams rarely have health care professionals working directly with the team, identifying players at increased risk through elaborate clinical tests is not feasible. Questionnaires may be a possible alternative as screening instruments.

Purpose

To examine whether injury history and lower limb function assessed by a self-administered questionnaire represent risk factors for injury.

Study Design

Cohort study; Level of evidence, 2.

Methods

At baseline, female soccer players (aged 14–16 years) were asked to complete a detailed questionnaire covering sports participation; history of previous injuries to the ankle, knee, hamstring, or groin; as well as present function of these 4 specific regions. A total of 1430 (71 % of the entire cohort) were followed up to record injuries during the subsequent 8 months.

Results

A history of a previous injury to the ankle (rate ratio, 1.2 [1.1–1.3]; P < .001), knee (rate ratio, 1.4 [1.2–1.6]; P< .001), or groin (rate ratio, 1.6 [1.2–2.1]; P = .004) increased the risk of new injuries to the same region. Reporting a reduced function (defined as <80% of the maximum score) for the ankle (rate ratio, 1.7 [1.1–2.7]; P = .021) or knee (rate ratio, 3.2 [1.8–5.7]; P < .001) was also a significant risk factor. However, the sensitivity of previous injuries and lower limb function in predicting new injuries was low.

Conclusion

A history of previous injury and reduced function at baseline were significant risk factors for new injuries to the same region during the following season.
The Role of Mentoring and Supervisor Support for State IT Employees' Affective Organizational Commitment
Authors: Reid Margaret F. , Allen Myria Watkins , Riemenschneider Cynthia K. , Armstrong Deborah J.
Published: January 2008

This article assesses the effects of psychosocial and career mentoring, leader—member exchange (LMX), and gender on the affective organizational commitment (AOC) of information technology (IT) employees working in one state government. Few studies have examined the relationship between mentoring and associated antecedents of the AOC of IT employees, and none has examined these relationships for public-sector workforces. The research finds that when both psychosocial and career mentoring are considered, only psychosocial mentoring was significant in predicting the AOC of state government IT employees. When considering just LMX, it was significant in predicting AOC. Neither psychosocial mentoring nor career mentoring was significant in predicting AOC if LMX is also considered. No gender differences were found for any of the variables examined.