bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel missense mutation in the FGB g. 3354 T>A (p. Y41N), Fibrinogen Caracas VIII
Authors: Rojas Héctor , Meyer Michael , Castillo Oscar , Sáez Ruiz Arlette De , Weisel John , Marchi Rita
Published: February 2011

A novel dysfibrinogenaemia with a replacement of Tyr by Asn at Bβ41 has been discovered (fibrinogen Caracas VIII). An asymptomatic 39-year-old male was diagnosed as having dysfibrinogenaemia due to a mildly prolonged thrombin time (+ 5.8 seconds); his fibrinogen concentration was in the low normal range, both by Clauss and gravimetric determination, 1.9 g/l and 2.1 g/l, respectively. The plasma polymerization process was slightly impaired, characterised by a mildly prolonged lag time and a slightly increased final turbidity. Permeation through the patients´ clots was dramatically increased, with the Darcy constant around four times greater than that of the control (22 ± 2 x10–9 cm2 compared to 6 ± 0.5 x10–9 cm2 in controls). The plasma fibrin structure of the patient, by scanning electron microscopy, featured a mesh composed of thick fibres (148 ± 50 nm vs. 120 ± 31 nm in controls, p<0.05) and larger pores than those of the control fibrin clot. The viscoelastic properties of the clot from the patient were also altered, as the storage modulus (G‘, 310 ± 30) was much lower than in the control (831 ± 111) (p ≤0.005). The interaction of the fibrin clot with a monolayer of human microvascular endothelial cells, by confocal laser microscopy, revealed that the patients´ fibrin network had less interaction with the cells. These results demonstrate the significance of the amino terminal end of the β chain of fibrin in the polymerisation process and its consequences on the clot organisation on the surface of endothelial cells.
Frequency of Platelet type versus Type 2B von Willebrand Disease
Authors: Hamilton Alexander , Ozelo Margareth , Leggo Jayne , Notley Colleen , Brown Hannah , Pablo Frontroth Juan , Angelillo-Scherrer Anne , Baghaei Fariba , Enayat Said , Favaloro Emmanuel , Lillicrap David , Othman Maha
Published: February 2011

Less than 50 patients are reported with platelet type von Willebrand disease (PT-VWD) worldwide. Several reports have discussed the diagnostic challenge of this disease versus the closely similar disorder type 2B VWD. However, no systematic study has evaluated this dilemma globally. Over three years, a total of 110 samples/data from eight countries were analysed. A molecular approach was utilised, analysing exon 28 of the von Willebrand factor (VWF) gene, and in mutation negative cases the platelet GP1BA gene. Our results show that 48 cases initially diagnosed as putative type 2B/PT-VWD carried exon 28 mutations consistent with type 2B VWD, 17 carried GP1BA mutations consistent with a PT-VWD diagnosis, three had other VWD types (2A and 2M) and five expressed three non-previously published exon 28 mutations. Excluding 10 unaffected family members and one acquired VWD, 26 cases did not have mutations in either genes. Based on our study, the percentage of type 2B VWD diagnosis is 44% while the percentage of misdiagnosis of PT-VWD is 15%. This is the first large international study to investigate the occurrence of PT-VWD and type 2B VWD worldwide and to evaluate DNA analysis as a diagnostic tool for a large cohort of patients. The study highlights the diagnostic limitations due to unavailability/poor application of RIPA and related tests in some centres and proposes genetic analysis as a suitable tool for the discrimination of the two disorders worldwide. Cases that are negative for both VWF and GP1BA gene mutations require further evaluation for alternative diagnoses.
Increased platelet aggregation and in vivo platelet activation after granulocyte colony-stimulating factor administration
Authors: Spiel Alexander , Bartko Johann , Schwameis Michael , Firbas Christa , Siller-Matula Jolanta , Schuetz Matthias , Weigl Manuela , Jilma Bernd
Published: February 2011

Granulocyte colony-stimulating factor (G-CSF) stimulates the bone marrow to produce granulocytes and stem cells and is widely used to accelerate neutrophil recovery after chemotherapy. Interestingly, specific G-CSF receptors have been demonstrated not only on myeloid cells, but also on platelets. Data on the effects of G-CSF on platelet function are limited and partly conflicting. The objective of this study was to determine the effect of G-CSF on platelet aggregation and in vivo platelet activation. Seventy-eight, healthy volunteers were enrolled into this randomised, placebo-controlled trial. Subjects received 5 μg/kg methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF, filgrastim) or placebo subcutaneously for four days. We determined platelet aggregation with a whole blood impedance aggregometer with various, clinically relevant platelet agonists (adenosine diphosphate [ADP], collagen, arachidonic acid [AA], ristocetin and thrombin receptor activating peptide 6 [TRAP]). Filgrastim injection significantly enhanced ADP (+40%), collagen (+60%) and AA (+75%) -induced platelet aggregation (all p<0.01 as compared to placebo and p<0.001 as compared to baseline). In addition, G-CSF enhanced ristocetin-induced platelet aggregation (+18%) whereas TRAP-induced platelet aggregation decreased slightly (-14%) in response to filgrastim. While baseline aggregation with all agonists was only slightly but insignificantly higher in women than in men, this sex difference was enhanced by G-CSF treatment, and became most pronounced for ADP after five days (p<0.001). Enhanced platelet aggregation translated into a 75% increase in platelet activation as measured by circulating soluble P-selectin. G-CSF enhances platelet aggregation and activation in humans. This may put patients suffering from cardiovascular disease and cancer at risk for thrombotic events.
An improved method for specific and quantitative determination of the clopidogrel active metabolite isomers in human plasma
Authors: Roy Sebastien , Lavisse Melanie , Brasseur Denis , Schofield Joe , Touchard Nathalie Delesque , Savi Pierre , Bremond Nicolas , Rouchon Marie-Claude , Hurbin Fabrice , Sultan Eric , Tuffal Gilles
Published: February 2011

Pharmacokinetic analyses of clopidogrel are hampered by the existence of multiple active metabolite isomers (H1 to H4) and their instability in blood. We sought to retest the pharmacodynamic activities of the four individual active metabolite isomers in vitro, with the ultimate aim of determining the isomers responsible for clopidogrel activity in vivo. In vitro activity was evaluated by measuring binding of [33P]-2-methylthio-ADP on P2Y12-expressing Chinese hamster ovary (CHO) cells and human platelets in platelet-rich plasma (PRP). A stereoselective method that used reverse-phase ultra high-performance liquid chromatography (UHPLC) and tandem mass spectrometry (MS) was developed to measure individual concentrations of the stable 3’-methoxyacetophe-none (MP) derivatives of H1–H4. The new method was used to analyze plasma samples from clopidogrel-treated subjects enrolled in a phase I clinical trial. In vitro binding assays confirmed the previously observed biological activity of H4 (IC50: CHO-P2Y12: 0.12 μM; PRP: 0.97 μM) and inactivity of H3, and demonstrated that H1 was also inactive. Furthermore, H2 demonstrated approximately half of the biological activity in vitro compared with H4. Optimisation of UHPLC conditions and MS collision parameters allowed the resolution and detection of the four derivatised active metabolite isomers (MP-H1 to MP-H4). The stereoselective assay was extensively validated, and was accurate and precise over the concentration range 0.5–250 ng/ml. Only MP-H3 and MP-H4 were quantifiable in incurred clinical samples. Based on in vitro pharmacodynamic data and found concentrations, the active metabolite isomer H4 is the only diastereoisomer of clinical relevance for documenting the pharmacokinetic profile of the active metabolite of clopidogrel.
Characterisation of factor IX with a glycine-to-valine missense mutation at residue 190 in a patient with severe haemophilia B
Authors: Kao Chung-Yang , Lin Chia-Ni , Yang Yung-Li , Hamaguchi Nobuko , Yang Shu-Jhu , Shen Ming-Ching , Kao Jau-Tsuen , Lin Shu-Wha
Published: February 2011

A patient with severe haemophilia B with a glycine-to-valine missense mutation at residue 190 (c25, chymotrypsin numbering) in factor IX (FIX; FIX-G190V or FIX-FuChou) had <1% of normal FIX clotting activity and 36% of normal FIX antigen levels (cross-reacting material-reduced, CRMr). Residue 190 in the C-terminal protease domain of human FIX is highly conserved in mammalian species and the serine protease family, suggesting that it has an indispensable role in protein function. To explore the pathological mechanism by which this mutation contributes to dysfunction of the FIX molecule, we functionally characterised FIX-G190V in vitro and in vivo. Liver-specific FIX-G190V gene expression following hydrodynamic plasmid delivery into haemophilia B mice revealed a 5.7-fold reduction in specific clotting activity compared with FIX-WT (wild type) and a two-fold decrease in plasma FIX-G190V concentration. Pulse-chase analysis demonstrated that FIX-G190V was secreted at a significantly slower rate than was FIX-WT. Purified FIX-G190V and FIX-WT displayed normal calcium-dependent conformational changes as shown by intrinsic fluorescence quenching. The in vivo half-lives of FIX-G190V and FIX-WT were indistinguishable. FIX-G190V was, however, more readily degraded than FIX-WT, especially after being activated by the active form of FXI. The vulnerable sites were mapped to the peptide bonds at Arg116-Leu117, Lys265-Tyr266, Arg327-Val328, and Arg338-Ser339, which are in the exposed loops of the FIX molecule. Also, failure of FXIa-activated FIX-G190V to bind p-aminobenzamidine indicated an abnormal conformation of the active-site pocket. Thus, the mutation at residue 190 of FIX may result in protein misfolding that affects secretion, clotting function, and hydrolysis.
IScore
Authors: Saposnik Gustavo , Kapral Moira K. , Liu Ying , Hall Ruth , O'Donnell Martin , Raptis Stavroula , Tu Jack V. , Mamdani Muhammad , Austin Peter C.
Published: February 2011

Background—

A predictive model of stroke mortality may be useful for clinicians to improve communication with and care of hospitalized patients. Our aim was to identify predictors of mortality and to develop and validate a risk score model using information available at hospital presentation.

Methods and Results—

This retrospective study included 12 262 community-based patients presenting with an acute ischemic stroke at multiple hospitals in Ontario, Canada, between 2003 and 2008 who had been identified from the Registry of the Canadian Stroke Network (8223 patients in the derivation cohort, 4039 in the internal validation cohort) and the Ontario Stroke Audit (3720 for the external validation cohort). The mortality rates for the derivation and internal validation cohorts were 12.2% and 12.6%, respectively, at 30 days and 22.5% and 22.9% at 1 year. Multivariable predictors of 30-day and 1-year mortality included older age, male sex, severe stroke, nonlacunar stroke subtype, glucose ≥7.5 mmol/L (135 mg/dL), history of atrial fibrillation, coronary artery disease, congestive heart failure, cancer, dementia, kidney disease on dialysis, and dependency before the stroke. A risk score index stratified the risk of death and identified low- and high- risk individuals. The c statistic was 0.850 for 30-day mortality and 0.823 for 1-year mortality for the derivation cohort, 0.851 for the 30-day model and 0.840 for the 1-year mortality model in the internal validation set, and 0.790 for the 30-day model and 0.782 for the 1-year model in the external validation set.

Conclusion—

Among patients with ischemic stroke, factors identifiable within hours of hospital presentation predicted mortality risk at 30 days and 1 year. The predictive score may assist clinicians in estimating stroke mortality risk and policymakers in providing a quantitative tool to compare facilities.
Equol-Stimulated Mitochondrial Reactive Oxygen Species Activate Endothelial Nitric Oxide Synthase and Redox Signaling in Endothelial Cells
Authors: Rowlands David J. , Chapple Sarah , Siow Richard C.M. , Mann Giovanni E.
Published: February 2011

We reported previously that dietary isoflavones modulate arterial blood pressure in vivo and that the daidzein metabolite equol rapidly activates endothelial NO synthase (eNOS) via Akt and extracellular signal–regulated kinase 1/2–dependent signaling. In this study, we report the first evidence in human endothelial cells that acute stimulation of mitochondrial superoxide generation by equol (100 nmol/L) is required for eNOS activation. Scavengers of superoxide (superoxide dismutase and manganese [III] tetrakis[1-methyl-4-pyridyl]porphyrin) abrogated equol stimulated Akt and eNOS phosphorylation, and the mitochondrial complex I inhibitor rotenone inhibited Akt, extracellular signal–regulated kinase 1/2, and eNOS phosphorylation, as well as NO-mediated increases in intracellular cGMP. Equol also induced rapid alterations in F-actin fiber distribution, with depolymerization of F-actin with cytochalasin D abrogating equol-stimulated mitochondrial superoxide generation. Treatment of cells with pertussis toxin or inhibition of GPR30/epidermal growth factor receptor kinase transactivation prevented equol-induced activation of extracellular signal–regulated kinase 1/2 via c-Src, Akt, and eNOS. Moreover, inhibition of epidermal growth factor receptor kinase activation with AG-1478 abrogated equol-stimulated mitochondrial reactive oxygen species generation and subsequent kinase and eNOS activation. Our findings suggest that equol-stimulated mitochondrial reactive oxygen species modulate endothelial redox signaling and NO release involving transactivation of epidermal growth factor receptor kinase and reorganization of the F-actin cytoskeleton. Identification of these novel actions of equol may provide valuable insights for therapeutic strategies to restore endothelial function in cardiovascular disease.
Early Sympathetic Activation in the Initial Clinical Stages of Chronic Renal Failure
Authors: Grassi Guido , Quarti-Trevano Fosca , Seravalle Gino , Arenare Francesca , Volpe Marco , Furiani Silvia , Dell'Oro Raffaella , Mancia Giuseppe
Published: February 2011

Direct and indirect indices of neuroadrenergic function have shown that end-stage renal disease is characterized by a marked sympathetic overdrive. It is unknown, however, whether this phenomenon represents a peculiar feature of end-stage renal disease or whether it is also detectable in the early clinical phases of the disease. The study has been performed in 73 hypertensive patients, of which there were 42 (age: 60.7±1.8 years, mean±SEM) with a stable moderate chronic renal failure (mean estimated glomerular filtration rate: 40.7 mL/min per 1.73 m
2
, MDRD formula) and 31 age-matched controls with a preserved renal function. Measurements included anthropometric variables, sphygmomanometric and beat-to-beat blood pressure, heart rate (ECG), venous plasma norepinephrine (high-performance liquid chromatography), and efferent postganglionic muscle sympathetic nerve activity (microneurography, peroneal nerve). For similar anthropometric and hemodynamic values, renal failure patients displayed muscle sympathetic nerve activity values significantly and markedly greater than controls (60.0±2.1 versus 45.7±2.0 bursts per 100 heartbeats;
P
<0.001). Muscle sympathetic nerve activity showed a progressive and significant increase from the first to the fourth quartile of the estimated glomerular filtration rate values (first: 41.0±2.7; second: 51.9±1.7; third: 59.8±3.0; fourth: 61.9±3.3 bursts per 100 heartbeats), the statistical significance (
P
<0.05) between groups being maintained after adjustment for confounders. In the population as a whole, muscle sympathetic nerve activity was significantly and inversely correlated with the estimated glomerular filtration rate (
r
=−0.59;
P
<0.0001). Thus, adrenergic activation is a phenomenon not confined to advanced renal failure but already detectable in the initial phases of the disease. The sympathetic overdrive parallels the severity of the renal failure, state and, thus, it might participate, in conjunction with other factors, at the disease progression.
Estrogen Receptor-β Signals Left Ventricular Hypertrophy Sex Differences in Normotensive Deoxycorticosterone Acetate-Salt Mice
Authors: Gürgen Dennis , Hegner Björn , Kusch Angelika , Catar Rusan , Chaykovska Lyubov , Hoff Uwe , Gross Volkmar , Slowinski Torsten , da Costa Goncalves Andrey C. , Kintscher Ulrich , Gustafsson Jan-Åke , Luft Friedrich C. , Dragun Duska
Published: February 2011

We found earlier that deoxycorticosterone acetate-salt treatment causes blood pressure–independent left ventricular hypertrophy, but only in male mice. To test the hypothesis that the estrogen receptor-β (ERβ) protects the females from left ventricular hypertrophy, we treated male and female ERβ-deficient (ERβ
−/−
) mice and their male and female littermates (wild-type [WT]) with deoxycorticosterone acetate-salt and made them telemetrically normotensive with hydralazine. WT males had increased (+16%) heart weight/tibia length ratios compared with WT females (+7%) at 6 weeks. In ERβ
−/−
mice, this situation was reversed. Female WT mice had the greatest heart weight/tibia length ratio increases of all of the groups (+23%), even greater than ERβ
−/−
males (+10%). Echocardiography revealed concentric left ventricular hypertrophy in male WT mice, whereas ERβ
−/−
females developed dilative left ventricular hypertrophy. The hypertrophic response in female ERβ
−/−
mice was accompanied by the highest degree of collagen deposition, indicating maladaptive remodeling. ERβ
+/+
females showed robust protective p38 and extracellular signal–regulated kinase 1/2 signaling relationships compared with other groups. Calcineurin Aβ expression and its positive regulator myocyte-enriched calcineurin-interacting protein 1 were increased in deoxycorticosterone acetate-salt female ERβ
−/−
mice, yet lower than in WT males. Endothelin increased murine cardiomyocyte hypertrophy in vitro, which could be blocked by estradiol and an ERβ agonist. We conclude that a functional ERβ is essential for inducing adaptive p38 and extracellular signal–regulated kinase signaling, while reducing maladaptive calcineurin signaling in normotensive deoxycorticosterone acetate female mice. Our findings address the possibility of sex-specific cardiovascular therapies.
Tropical Oceanic Response to Extratropical Thermal Forcing in a Coupled Climate Model: A Comparison between the Atlantic and Pacific Oceans*
Authors: Yang Haijun , Wang Lu
Published: February 2011

The tropical oceanic response to the extratropical thermal forcing is quantitatively estimated in a coupled climate model. This work focuses on comparison of the responses between the tropical Atlantic and Pacific. Under the same extratropical forcing, the tropical sea surface temperature responses are comparable. However, the responses in the tropical subsurface in the two oceans are distinct. The tropical subsurface response in the Atlantic can be twice of that in the Pacific. The maximum subsurface temperature change in the tropical Pacific occurs in the eastern lower thermocline, while that in the tropical Atlantic occurs in the west and well below the lower thermocline. The different responses in the tropical Atlantic and Pacific are closely related to the different changes in the meridional overturning circulations. The Pacific shallow overturning circulation, or the subtropical cell, tends to slow down (speed up) in response to the extratropical warming (cooling) forcing. The changes in the upwelling in the eastern equatorial Pacific as well as the shallow subduction from the extratropical southern Pacific along the eastern boundary are accountable for the eastern Pacific temperature change. The Atlantic overturning circulation consists of the shallow subtropical cell and the deep thermohaline circulation. A weakened thermohaline circulation will result in a strengthened northern subtropical cell, in which the change in the lower branch, or the low-latitude North Brazil Current, can cause strong response below the western tropical thermocline. Here the coastal Kelvin wave along the western boundary on the intermediate isopycnal level also plays an important role in the equatorward conveying of the climate anomalies in the mid-to-high-latitude Atlantic, particularly during the initial stage of the extratropical forcing.
Verification and Intercomparison of Multimodel Simulated Land Surface Hydrological Datasets over the United States
Authors: Fan Yun , van den Dool Huug M. , Wu Wanru
Published: February 2011

Several land surface datasets, such as the observed Illinois soil moisture dataset; three retrospective offline run datasets from the Noah land surface model (LSM), Variable Infiltration Capacity (VIC) LSM, and Climate Prediction Center leaky bucket soil model; and three reanalysis datasets (North American Regional Reanalysis, NCEP/Department of Energy Global Reanalysis, and 40-yr ECMWF Re-Analysis), are used to study the spatial and temporal variability of soil moisture and its response to the major components of land surface hydrologic cycles: precipitation, evaporation, and runoff. Detailed analysis was performed on the evolution of the soil moisture vertical profile. Over Illinois, model simulations are compared to observations, but for the United States as a whole some impressions can be gained by comparing the multiple soil moisture–precipitation–evaporation–runoff datasets to one another. The magnitudes and partitioning of major land surface water balance components on seasonal–interannual time scales have been explored. It appears that evaporation has the most prominent annual cycle but its interannual variability is relatively small. For other water balance components, such as precipitation, runoff, and surface water storage change, the amplitudes of their annual cycles and interannual variations are comparable. This study indicates that all models have a certain capability to reproduce observed soil moisture variability on seasonal–interannual time scales, but offline runs are decidedly better than reanalyses (in terms of validation against observations) and more highly correlated to one another (in terms of intercomparison) in general. However, noticeable differences are also observed, such as the degree of simulated drought severity and the locations affected—this is due to the uncertainty in model physics, input forcing, and mode of running (interactive or offline), which continue to be major issues for land surface modeling.
Erosion of a Surface Vortex by a Seamount
Authors: Herbette Steven , Morel Yves , Arhan Michel
Published: February 2011

Numerical experiments are carried out on the f plane, using a shallow-water isopycnal model, to analyze the behavior of a surface-intensified anticyclonic vortex when it encounters an isolated seamount. The advection by the vortex of deep fluid parcels across the isobaths is known to generate deep anticyclonic and cyclonic circulations above and near the bathymetry, respectively. These circulations are shown to exert a strong shear on the upper layers, which causes an erosion of the initial vortex by filamentation. The erosion often results in a subdivision of the eddy. While the eroded original structure forms a dipole with the deep cyclone and is advected away, the filaments torn off from the original core aggregate into a new eddy above the seamount. Splitting in more than two structures is sometimes observed. The erosion process is quantified by the bulk volume integral of the eddy potential vorticity anomaly. A sensitivity study to different parameters of the configuration (distance between vortex and seamount, vortex radius, seamount radius, seamount height, or stratification) shows that the intensities of the deep anticyclonic and cyclonic circulations and the vortex erosion are governed both by the reservoir of positive potential vorticity associated with the seamount and by the strength of the cross-isobath flow induced by the eddy.
Influence of Vertical Mixing on the Thermohaline Hysteresis: Analyses of an OGCM
Authors: Prange Matthias , Lohmann Gerrit , Paul André
Published: February 2011

The thermohaline hysteresis response to varying North Atlantic freshwater forcing is studied by means of a three-dimensional global ocean general circulation model (OGCM). The influence of vertical diffusivity is examined using a wide range of mixing coefficients. For sufficiently large vertical diffusivity the model shows a pronounced hysteresis behavior, so that two equilibrium states of the thermohaline circulation are found: one mode with intense deep-water formation in the North Atlantic (“on” mode) and one mode with strongly reduced convective activity (“off” mode). By decreasing the diffusivity, the two branches of the hysteresis merge. In addition, the effect of numerical diffusion is analyzed by applying different advection schemes. A positive feedback between overturning strength and the numerical diffusivity of upstream advection is found, resulting in a reduced stability of the “on” mode. Comparing the results with those from zonally averaged models exhibits substantial differences regarding the stability properties of the thermohaline circulation. Freshwater transports by horizontal gyres have an important effect on the overturning circulation in the OGCM.
The M2 Internal Tide off Oregon: Inferences from Data Assimilation
Authors: Kurapov Alexander L. , Egbert Gary D. , Allen J. S. , Miller Robert N. , Erofeeva Svetlana Y. , Kosro P. M.
Published: February 2011

A linearized baroclinic, spectral-in-time tidal inverse model has been developed for assimilation of surface currents from coast-based high-frequency (HF) radars. Representer functions obtained as a part of the generalized inverse solution show that for superinertial flows information from the surface velocity measurements propagates to depth along wave characteristics, allowing internal tidal flows to be mapped throughout the water column. Application of the inverse model to a 38 km × 57 km domain off the mid-Oregon coast, where data from two HF radar systems are available, provides a uniquely detailed picture of spatial and temporal variability of the M2 internal tide in a coastal environment. Most baroclinic signal contained in the data comes from outside the computational domain, and so data assimilation (DA) is used to restore baroclinic currents at the open boundary (OB). Experiments with synthetic data demonstrate that the choice of the error covariance for the OB condition affects model performance. A covariance consistent with assumed dynamics is obtained by nesting, using representers computed in a larger domain. Harmonic analysis of currents from HF radars and an acoustic Doppler profiler (ADP) mooring off Oregon for May–July 1998 reveals substantial intermittence of the internal tide, both in amplitude and phase. Assimilation of the surface current measurements captures the temporal variability and improves the ADP/solution rms difference. Despite significant temporal variability, persistent features are found for the studied period; for instance, the dominant direction of baroclinic wave phase and energy propagation is always from the northwest. At the surface, baroclinic surface tidal currents (deviations from the depth-averaged current) can be 10 cm s–1, 2 times as large as the depth-averaged current. Barotropic-to-baroclinic energy conversion is generally weak within the model domain over the shelf but reaches 5 mW m–2 at times over the slopes of Stonewall Bank.
Numerical Simulation of Sea Surface Directional Wave Spectra under Hurricane Wind Forcing
Authors: Moon Il-Ju , Ginis Isaac , Hara Tetsu , Tolman Hendrik L. , Wright C. W. , Walsh Edward J.
Published: February 2011

Numerical simulation of sea surface directional wave spectra under hurricane wind forcing was carried out using a high-resolution wave model. The simulation was run for four days as Hurricane Bonnie (1998) approached the U.S. East Coast. The results are compared with buoy observations and NASA Scanning Radar Altimeter (SRA) data, which were obtained on 24 August 1998 in the open ocean and on 26 August when the storm was approaching the shore. The simulated significant wave height in the open ocean reached 14 m, agreeing well with the SRA and buoy observations. It gradually decreased as the hurricane approached the shore. In the open ocean, the dominant wavelength and wave direction in all four quadrants relative to the storm center were simulated very accurately. For the landfall case, however, the simulated dominant wavelength displays noticeable overestimation because the wave model cannot properly simulate shoaling processes. Direct comparison of the model and SRA directional spectra in all four quadrants of the hurricane shows excellent agreement in general. In some cases, the model produces smoother spectra with narrower directional spreading than do the observations. The spatial characteristics of the spectra depend on the relative position from the hurricane center, the hurricane translation speed, and bathymetry. Attempts are made to provide simple explanations for the misalignment between local wind and wave directions and for the effect of hurricane translation speed on wave spectra.
Reconciling the Stommel Box Model with the Stommel–Arons Model: A Possible Role for Southern Hemisphere Wind Forcing?
Authors: Greatbatch Richard J. , Lu Jian
Published: February 2011

In the Stommel box model, the strength of the overturning circulation is parameterized in terms of the density (and hence the pressure) difference between the two boxes. Straub has pointed out that this parameterization is not consistent with the Stommel–Arons model for the abyssal circulation. In particular, the zonally averaged density field implied by the Stommel–Arons model is unrelated to the strength or the direction of the meridional overturning circulation. Here, the inconsistency is examined using the abyssal circulation model of Kawase and a variant to include the effect of Southern Hemisphere wind forcing. The important parameter is R, the ratio of two timescales: the timescale for a perturbation to the density field to propagate, by either wave or advective processes, from a high-latitude source to the equator and the timescale for the dissipation of a perturbation to the density field by diapycnal mixing. If the model is forced only by a deep water source in the northern basin, it is found that the model behaves like the Stommel–Arons model when R ≪ 1 (the “weak” damping regime) and like the Stommel box model when R ≫ 1 (the “strong” damping regine). Estimates of R suggest that coarse-resolution models generally reside in or near the Stommel box model regime (R ≫ 1), which is probably why these models generally support the Stommel box model hypothesis and corroborate the momentum-based closure used in zonally averaged models. On the other hand, it is not clear that the real world is also in the strong damping regime. Indeed, it is easy to obtain estimates for R, using realistic parameter values, that sit in the weak damping regime. It is shown that, even in the weak damping regime (R ≪ 1), adding forcing by the Southern Hemisphere circumpolar westerlies generally moves the model into the Stommel box model regime. It therefore is concluded that, at least in the context of the Kawase model, the inconsistency noted by Straub can be removed by including the effect of Southern Hemisphere wind forcing and that the Stommel box model approach probably has wider applicability than is suggested by estimates of R alone.
Annual ENSO
Authors: Tozuka Tomoki , Yamagata Toshio
Published: February 2011

Using various observational data, the seasonal cycle of the tropical Pacific is investigated, suggesting the existence of an “annual El Niño–Southern Oscillation (ENSO).” A positive sea surface temperature anomaly (SSTA) appearing off Peru in boreal winter triggers a series of air–sea interactions that consist of westward propagations of positive SSTA, westerly wind anomalies, and negative outgoing longwave radiation anomalies. At the same time, the westerly wind anomaly generates cold temperature anomalies in the off-equatorial region, and they propagate westward as a “cold” Rossby wave, reaching the western tropical Pacific in boreal summer to autumn. A semiresonant condition between the westward propagating component of winds and the first-meridional-mode Rossby wave plays an important role in the amplification. The evolution of cold phase in the latter half of the year is almost a mirror image of the warm phase. From a new viewpoint of the annual ENSO, the ENSO is interpreted as the interaction between two distinct modes of air–sea interaction: the annual ENSO mode and an “interannual ENSO” mode. The eastward-propagating interannual ENSO mode is an air–sea coupled mode, which is triggered by the westerly wind stress anomaly in the western equatorial Pacific and leads to the deepening of the thermocline and the warming of SST in the central and eastern equatorial Pacific. This results in a modulation of the annual ENSO mode with a weaker cold season and stronger warm season owing to less effective upwelling of the cold subsurface water. The decadal variation of ENSO is explained by changes in the relative phase and amplitude of these two modes. The increase in the amplitude of the interannual ENSO mode after the late 1970s favors the appearance of the eastward propagation of ENSO signals.
Subinertial Response of a Density-Driven Eastern Boundary Poleward Current to Wind Forcing
Authors: Peliz Álvaro , Dubert Jesús , Haidvogel Dale B.
Published: February 2011

A high-resolution primitive equation numerical model is used to generate a poleward flow along a meridionally oriented eastern boundary slope/shelf system by imposing an along-coast density gradient as the forcing mechanism. Wind forcing is applied to the resulting quasi-steady current system, and the subinertial response is analyzed. Parallel experiments with no slope-poleward flow are conducted for comparison. Moderately strong upwelling- and downwelling-favorable, week-to-month-scale wind events modify the poleward flow but do not significantly change the density-driven current structure at the slope. The alongshore transport within the slope region is reduced by 0.2–0.3 Sv (from 1.2 Sv, where Sv ≡ 106 m3 s–1), under the influence of either downwelling or upwelling winds. Independent of the wind direction, the density-driven poleward flow always remains surface intensified. Wind-driven shelf currents develop with a considerable degree of independence from the slope-poleward circulation. On the shelf, the density field is modified by cross-shelf buoyancy advection within the boundary layers and by strong vertical mixing. The presence of the poleward flow over the slope constitutes an important factor in the behavior of the bottom boundary layer at the shelf break and for the patterns of cross-slope circulation.
Kuroshio Extension Variability and Forcing of the Pacific Decadal Oscillations: Responses and Potential Feedback
Authors: Qiu Bo
Published: February 2011

A forcing mechanism is sought for the large-scale circulation changes in the Kuroshio Extension region of the western North Pacific Ocean as inferred by TOPEX/Poseidon sea surface height (SSH) data. The low-frequency signal of the Kuroshio Extension over the last decade was characterized by a modulation in its zonal mean flow intensity: the mean Kuroshio Extension jet weakened progressively from 1993 to 1996 and this trend reversed after 1997. The ability to simulate the major trends in the observed SSH signals with linear vorticity dynamics leads the authors to conclude that the modulation in the zonal mean jet was remotely forced by wind stress curl anomalies in the eastern North Pacific Ocean related to the Pacific decadal oscillations (PDOs). To be specific, the weakening (strengthening) trend in 1993–96 (1997–2001) was caused by westward expansions of negative (positive) SSH anomalies south of the Kuroshio Extension and positive (negative) SSH anomalies north of the Kuroshio Extension. Emergence of oppositely signed SSH anomalies on the two sides of the Kuroshio Extension jet is due to the different propagating speeds of the baroclinic Rossby waves, which carry the wind-induced SSH anomalies generated in the eastern North Pacific at different phases of the PDOs. Hindcasting the Kuroshio Extension jet strength over the last 45 years reveals that the jet modulation has a dominant timescale of ∼12 yr. Given the location of the Kuroshio Extension jet relative to the maximum atmospheric forcing, it is found that this dominant timescale is consistent with the preferred timescale under a stochastic white-noise atmospheric forcing. It is hypothesized that this connection between the Kuroshio Extension strength and the latitudinally dependent baroclinic adjustment contributes to an increase in variance and persistence of the North Pacific midlatitude coupled system on the decadal timescale.
Computerized Classification Testing Under the Generalized Graded Unfolding Model
Authors: Wang Wen-Chung , Liu Chen-Wei
Published: February 2011

The generalized graded unfolding model (GGUM) has been recently developed to describe item responses to Likert items (agree—disagree) in attitude measurement. In this study, the authors (a) developed two item selection methods in computerized classification testing under the GGUM, the current estimate/ability confidence interval method and the cut score/sequential probability ratio test method and (b) evaluated their accuracy and efficiency in classification through simulations. The results indicated that both methods were very accurate and efficient. The more points each item had and the fewer the classification categories, the more accurate and efficient the classification would be. However, the latter method may yield a very low accuracy in dichotomous items with a short maximum test length. Thus, if it is to be used to classify examinees with dichotomous items, the maximum text length should be increased.
A Reliability Generalization Meta-Analysis of Coefficient Alpha for the Maslach Burnout Inventory
Authors: Wheeler Denna L. , Vassar Matt , Worley Jody A. , Barnes Laura L. B.
Published: February 2011

The purpose of this study was to synthesize internal consistency reliability for the subscale scores on the Maslach Burnout Inventory (MBI). The authors addressed three research questions: (a) What is the mean subscale score reliability for the MBI across studies? (b) What factors are associated with observed variance in MBI subscale score reliability? (c) What are the implications for appropriate use based on MBI subscale mean internal consistency estimates? Of the 221 studies reviewed, 84 provided alpha coefficients and were used in the current analysis. Results suggest that mean alpha estimates across subscales generally fell within the .70 to .80 range. Scale variance and language most often accounted for the variance in coefficient alpha, although some variations were apparent between subscales. Of the three MBI subscales, Personal Accomplishment and Depersonalization mean alpha estimates were well below recommended levels for high-stakes decisions, such as the diagnosis of burnout syndrome. Recommendations for the use of the current version of the instrument’s scale scores as well as suggestions for scale refinement are provided.
Development and Assessment of the Social Issues Advocacy Scale
Authors: Nilsson Johanna E. , Marszalek Jacob M. , Linnemeyer Rachel M. , Bahner Angela D. , Misialek Leah Hanson
Published: February 2011

This article describes the development and the initial psychometric evaluation of the Social Issues Advocacy Scale in two studies. In the first study, an exploratory factor analysis (n = 278) revealed a four-factor scale, accounting for 71.4% of the variance, measuring different aspects of social issue advocacy: Political and Social Advocacy, Confronting Discrimination, Political Awareness, and Social Issue Awareness. The second study (n = 509) supported the structure. Results indicated excellent internal reliability and associations with another social advocacy scale, political interest, and multicultural empathy, but not with self-esteem and life satisfaction; all of which provided initial evidence of construct and discriminant validity.
Change Recipients’ Reactions to Organizational Change
Authors: Oreg Shaul , Vakola Maria , Armenakis Achilles
Published: February 2011

This study reviews quantitative empirical studies of change recipients’ reactions to organizational change. The authors reviewed studies published between 1948 and 2007, out of which 79 met the criteria of being quantitative studies of change recipients’ reactions to an organizational change. Through an inductive review, the authors unravel a model of (a) explicit reactions to change, in which these reactions are conceptualized as tridimensional attitudes; (b) reaction antecedents that comprise prechange antecedents (viz., change recipient characteristics and internal context) and change antecedents (viz., change process, perceived benefit/harm, and change content); and (c) change consequences, including work-related and personal consequences. On the basis of their review the authors conclude by proposing directions for future research and practical managerial implications.
Networks of Collaborating Criminals: Assessing the Structural Vulnerability of Drug Markets
Authors: Malm Aili , Bichler Gisela
Published: February 2011

Uncovering the resiliency of ties between individuals involved in criminal enterprise will contribute to our understanding of how illicit markets function. To examine activities along the entire drug market commodity chain, this study extracted information about individuals involved or associated with trafficking (1,998 people) from police intelligence reports generated from 2004 to 2006. Significant differences were found for centrality and cohesion across market niches. Results show that the highest fragmentation potential lies with individuals who are involved with smuggling, supply, and financing, particularly when these individuals are also involved in other niches. Variability in small-world and scale-free properties suggest that interdiction strategies must be tailored to niche characteristics.
Examining Juvenile Delinquency within Activity Space: Building a Context for Offender Travel Patterns
Authors: Bichler Gisela , Christie-Merrall Jill , Sechrest Dale
Published: February 2011

Researchers modeling offender travel patterns typically assume that crime locations are well within the offenders’ activity space. Using information about the places frequented by 2,563 delinquent youths residing in Southern California, this study examined distances traveled to delinquent and nondelinquent hangout locations. Travel to known delinquent sites was substantively farther from home than expected and exhibited a segmented nonlinear curve, joining logarithmic and negative exponential functions. Significant variation was found for place-specific (trip distance) and person-specific (individual travel) distances by city classification, travel method, and age cohort; age effects disappeared in multivariate analyses. Several implications follow, highlighting the need to infuse a place-oriented approach to studying journey-to-crime.
Differences in Myers-Briggs Personality Types Among High School Band, Orchestra, and Choir Members
Authors: Reardon MacLellan Christin
Published: February 2011

The purpose of this study was to explore personality type differences among high school band, string orchestra, and choir students according to ensemble membership. Participants ( N = 355) were high school students who had participated in their school’s band, orchestra, or choir for 1 year or more. The author administered the Myers-Briggs Type Indicator (MBTI) to determine the personality type for each participant. Personality types were compared among the three ensembles as well as with published MBTI high school norms. Results indicated that personality type differences existed among the ensembles and that there were significant differences in the comparisons with MBTI norms. A significant personality type difference was found between orchestra and choir students along the Extraversion-Introversion dichotomy, indicating that choir students were more likely to be Extraverted when compared to orchestra students. There were no significant differences among the ensembles on the Sensing-Intuition, Thinking-Feeling, or Judging-Perceiving scales. Compared to high school norms, the students in each ensemble were significantly more likely to be Intuitive and Feeling. The band students were significantly more likely to be Perceiving, and the choir students were significantly more likely to be Extraverted.
The Effect of Pitch and Rhythm Difficulty on Vocal Sight-Reading Performance
Authors: Henry Michele L.
Published: February 2011

Singing music at sight is a complex skill, requiring the singer to perform pitch and rhythm simultaneously. Previous research has identified difficulty levels for pitch and rhythm skills individually but not in combination. In this study, the author sought to determine the relationship between pitch and rhythm tasks occurring concurrently. High school singers ( N = 252) sang melodies with varying combinations of pitch and rhythm difficulty. Results indicate that pitch and rhythm skills retained their relative difficulty levels, regardless of the presence of other factors. Rhythmic success was significantly related to pitch success. Rhythm accuracy without pitch success occurred least frequently. Pitch accuracy without rhythm success occurred most frequently. Singers appeared to give priority to pitch over rhythm, performing pitch correctly at the expense of rhythmic accuracy. Singers with instrument/piano experience and singers with piano experience only scored significantly higher than did those with no instrument/piano training ( p < .05). Those with instrument and/or piano experience were more proficient at performing pitch and rhythm together than those without such experience. Implications for teachers include the necessity of emphasizing rhythmic continuity. Future research should explore the pitch and rhythm reading capabilities for instrumentalists, and singers’ ability to sight-read additional musical elements.
Public Policy Design in Developing Societies
Authors: Pessali Huascar
Published: February 2011

The transplantation of public policies is a powerful tool in the hands of economic development. Powerful as it may be, transplantation verbatim et litteratim is not inevitably successful, thus not always desirable. There are good economic reasons to consider the practice of grafting in public policy transplants, i.e., consideration for the specificities of existing local institutions and how they may interact with a set of more overarching policy requirements and guidelines. An architecture for public policy design that institutionalizes some sort of negotiation between policy makers and stakeholders may provide a midway that avoids some of the intrinsic risks of standard transplantation architectures.