bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferon-γ and the Interferon-Inducible Chemokine CXCL10 Protect Against Aneurysm Formation and Rupture
Authors: King Victoria L. , Lin Alexander Y. , Kristo Fjoralba , Anderson Thomas J.T. , Ahluwalia Neil , Hardy Gregory J. , Owens A. Phillip , Howatt Deborah A. , Shen Dongxiao , Tager Andrew M. , Luster Andrew D. , Daugherty Alan , Gerszten Robert E.
Published: January 2009

Background—

Vascular disease can manifest as stenotic plaques or ectatic aneurysms, although the mechanisms culminating in these divergent disease manifestations remain poorly understood. T-helper type 1 cytokines, including interferon-γ and CXCL10, have been strongly implicated in atherosclerotic plaque development.

Methods and Results—

Here, we specifically examined their role in the formation of abdominal aortic aneurysms in the angiotensin II–induced murine model. Unexpectedly, we found increased suprarenal aortic diameters, abdominal aortic aneurysm incidence, and aneurysmal death in apolipoprotein E– and interferon-γ–deficient (

Apoe
−/−
/Ifng
−/−

) mice compared with

Apoe
−/−

controls, although atherosclerotic luminal plaque formation was attenuated. The interferon-γ–inducible T-cell chemoattractant CXCL10 was highly induced by angiotensin II infusion in

Apoe
−/−

mice, but this induction was markedly attenuated in

Apoe
−/−
/Ifng
−/−

mice.

Apoe
−/−
/Cxcl10
−/−

mice had decreased luminal plaque but also increased aortic size, worse morphological grades of aneurysms, and a higher incidence of death due to aortic rupture than Apoe
−/−
controls. Furthermore, abdominal aortic aneurysms in

Apoe
−/−
/Cxcl10
−/−

mice were enriched for non–T-helper type 1–related signals, including transforming growth factor-β1. Treatment of

Apoe
−/−
/Cxcl10
−/−

mice with anti-transforming growth factor-β neutralizing antibody diminished angiotensin II–induced aortic dilation.

Conclusions—

The present study defines a novel pathway in which interferon-γ and its effector, CXCL10, contribute to divergent pathways in abdominal aortic aneurysm versus plaque formation, inhibiting the former pathology but promoting the latter. Thus, efforts to develop antiinflammatory strategies for atherosclerosis must carefully consider potential effects on all manifestations of vascular disease.
Prevalence and Progression of Subclinical Atherosclerosis in Younger Adults With Low Short-Term but High Lifetime Estimated Risk For Cardiovascular Disease
Authors: Berry Jarett D. , Liu Kiang , Folsom Aaron R. , Lewis Cora E. , Carr J. Jeffrey , Polak Joseph F. , Shea Steven , Sidney Stephen , O'Leary Daniel H. , Chan Cheeling , Lloyd-Jones Donald M.
Published: January 2009

Background—

We hypothesized that individuals with low 10-year but high lifetime cardiovascular disease risk would have a greater burden of subclinical atherosclerosis than those with low 10-year but low lifetime risk.

Methods and Results—

We included 2988 individuals ≤50 years of age at examination year 15 from the Coronary Artery Risk Development in Young Adults (CARDIA) study and 1076 individuals ≤50 of age at study entry from the Multi-Ethnic Study of Atherosclerosis (MESA). The 10-year risk and lifetime risk for cardiovascular disease were estimated for each participant, permitting stratification into 3 groups: low 10-year (<10%)/low lifetime (<39%) risk, low 10-year (<10%)/high lifetime risk (≥39%), and high 10-year risk (≥10%) or diagnosed diabetes mellitus. Baseline levels and change in levels of subclinical atherosclerosis (coronary artery calcium or carotid intima-media thickness) were compared across risk strata. Among participants with low 10-year risk (91% of all participants) in CARDIA, those with a high lifetime risk compared with low lifetime risk had significantly greater common (0.83 versus 0.80 mm in men; 0.79 versus 0.75 mm in women) and internal (0.85 versus 0.80 mm in men; 0.80 versus 0.76 mm in women) carotid intima-media thickness, higher coronary artery calcium prevalence (16.6% versus 9.8% in men; 7.1% versus 2.3% in women), and significantly greater incidence of coronary artery calcium progression (22.3% versus 15.4% in men; 8.7% versus 5.3% in women). Similar results were observed in MESA.

Conclusions—

Individuals with low 10-year but high lifetime risk have a greater subclinical disease burden and greater incidence of atherosclerotic progression compared with individuals with low 10-year and low lifetime risk, even at younger ages.
Circulating Endothelial Cells
Authors: Smadja David M. , Gaussem Pascale , Mauge Laetitia , Israël-Biet Dominique , Dignat-George Françoise , Peyrard Séverine , Agnoletti Gabriella , Vouhé Pascal R. , Bonnet Damien , Lévy Marilyne
Published: January 2009

Background—

Congenital heart disease can be complicated by pulmonary arterial hypertension (PAH), the reversibility of which is often difficult to predict. We recently reported a lung biopsy study showing impaired apoptotic regulation of endothelial cells in irreversible PAH. The objective of the present study was to identify noninvasive biomarkers of endothelial turnover that could be used to identify congenital heart disease patients at risk of irreversible PAH.

Methods and Results—

Circulating endothelial cells (CECs) isolated with CD146-coated beads and circulating CD34
+
CD133
+
progenitor cells (CPCs) were quantified in peripheral vein, pulmonary artery, and pulmonary vein blood samples from 26 patients with congenital heart disease (16 with reversible PAH [median age 2 years] and 10 with irreversible PAH [median age 9 years]) and 5 control patients. Surgical lung biopsy was performed in 19 cases. As expected, endothelial remodeling was observed in irreversible PAH but not in reversible PAH. CEC and CPC numbers were each similar in the 3 types of blood samples. CEC numbers were significantly higher in patients with irreversible PAH (median 57 CEC/mL) than in patients with reversible PAH and control subjects (median 3 CEC/mL in the 2 groups). In contrast, CPC numbers did not differ among patients with irreversible or reversible PAH and control subjects (median 84, 64, and 44 CPC/10
5
lymphocytes, respectively, in the 3 groups).

Conclusions—

Irreversible PAH in congenital heart disease is associated with endothelial damage and with increased circulating endothelial cell counts. The present study suggests that CECs could be a valuable tool to define therapeutic strategies in congenital heart disease patients with PAH.
Patient Health Status and Costs in Heart Failure
Authors: Chan Paul S. , Soto Gabriel , Jones Philip G. , Nallamothu Brahmajee K. , Zhang Zefeng , Weintraub William S. , Spertus John A.
Published: January 2009

Background—

Although a variety of prognostic tools have been shown to predict rehospitalization and mortality in heart failure patients, their utility in assessing future costs is less clear. We assessed whether health status assessment with the Kansas City Cardiomyopathy Questionnaire (KCCQ) predicts future costs in stable heart failure outpatients with left ventricular dysfunction after myocardial infarction.

Methods and Results—

We evaluated 12-month cost utilization data from 1516 heart failure outpatients enrolled in the Quality-of-Life Substudy of the Eplerenone Post–Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS). Multivariable hierarchical models assessed whether the KCCQ (categorized as 0 to <25, 25 to <50, 50 to <75, and 75 to 100) was an independent predictor of future resource use. At baseline, 685 patients (45.2%) had good health status (KCCQ scores ≥75), whereas 510 (33.6%), 262 (17.3%), and 59 (3.9%) had fair (KCCQ, 50 to 74), poor (KCCQ, 25 to 49), and the worst (KCCQ <25) health status, respectively. After multivariable adjustment, compared with patients with good health status, patients with fair health status incurred incremental 1-year costs of $1520 (cost ratio, 1.23; 95% confidence interval, 1.05 to 1.43), whereas patients with poor and the worst health status incurred incremental 1-year costs of $4265 (cost ratio, 1.63; 95% confidence interval, 1.34 to 1.99) and $8999 (cost ratio, 2.34; 95% confidence interval, 1.62 to 3.38), respectively (
P
<0.0001 for association with KCCQ). Further adjustment for New York Heart Association class led to only partial attenuation of this relationship (
P
=0.0002).

Conclusion—

Health status assessment predicts resource use and costs over the next year in stable heart failure outpatients with left ventricular dysfunction after myocardial infarction.
Impaired Vasodilator Activity in Deoxycorticosterone Acetate-Salt Hypertension Is Associated With Increased Protein O-GlcNAcylation
Authors: Lima Victor V. , Giachini Fernanda R.C. , Choi Hyehun , Carneiro Fernando S. , Carneiro Zidonia N. , Fortes Zuleica B. , Carvalho Maria Helena C. , Webb R. Clinton , Tostes Rita C.
Published: January 2009

Hyperglycemia, which increases O-linked β-
N
-acetylglucosamine (O-GlcNAc) proteins, leads to changes in vascular reactivity. Because vascular dysfunction is a key feature of arterial hypertension, we hypothesized that vessels from deoxycorticosterone acetate and salt (DOCA-salt) rats exhibit increased O-GlcNAc proteins, which is associated with increased reactivity to constrictor stimuli. Aortas from DOCA rats exhibited increased contraction to phenylephrine (E
max
[mN]=17.6±4 versus 10.7±2 control; n=6) and decreased relaxation to acetylcholine (47.6±6% versus 73.2±10% control; n=8) versus arteries from uninephrectomized rats. O-GlcNAc protein content was increased in aortas from DOCA rats (arbitrary units=3.8±0.3 versus 2.3±0.3 control; n=5). PugNAc (O-GlcNAcase inhibitor; 100 μmol/L; 24 hours) increased vascular O-GlcNAc proteins, augmented phenylephrine vascular reactivity (18.2±2 versus 10.7±3 vehicle; n=6), and decreased acetylcholine dilation in uninephrectomized (41.4±6 versus 73.2±3 vehicle; n=6) but not in DOCA rats (phenylephrine, 16.5±3 versus 18.6±3 vehicle, n=6; acetylcholine, 44.7±8 versus 47.6±7 vehicle, n=6). PugNAc did not change total vascular endothelial nitric oxide synthase levels, but reduced endothelial nitric oxide synthase
Ser-1177
and Akt
Ser-473
phosphorylation (
P
<0.05). Aortas from DOCA rats also exhibited decreased levels of endothelial nitric oxide synthase
Ser-1177
and Akt
Ser-473
(
P
<0.05) but no changes in total endothelial nitric oxide synthase or Akt. Vascular O-GlcNAc–modified endothelial nitric oxide synthase was increased in DOCA rats. Blood glucose was similar in DOCA and uninephrectomized rats. Expression of O-GlcNAc transferase, glutamine:fructose-6-phosphate amidotransferase, and O-GlcNAcase, enzymes that directly modulate O-GlcNAcylation, was decreased in arteries from DOCA rats (
P
<0.05). This is the first study showing that O-GlcNAcylation modulates vascular reactivity in normoglycemic conditions and that vascular O-GlcNAc proteins are increased in DOCA-salt hypertension. Modulation of increased vascular O-GlcNAcylation may represent a novel therapeutic approach in mineralocorticoid hypertension.
When Right Makes Might: How Prussia Overturned the European Balance of Power
Authors: Goddard Stacie E.
Published: January 2009

From 1864 to 1871, Prussia mounted a series of wars that fundamentally altered the balance of power in Europe. Yet no coalition emerged to check Prussia's rise. Rather than balance against Prussian expansion, the great powers sat on the sidelines and allowed the transformation of European politics. Traditionally, scholars have emphasized structural variables, such as mulitpolarity, or domestic politics as the cause of this “underbalancing.” It was Prussia's legitimation strategies, however—the way Prussia justified its expansion—that undermined a potential balancing coalition. As Prussia expanded, it appealed to shared rules and norms, strategically choosing rhetoric that would resonate with each of the great powers. These legitimation strategies undermined balancing coalitions through three mechanisms: by signaling constraint, laying rhetorical traps (i.e., framing territorial expansion in a way that deprived others states grounds on which to resist), and increasing ontological security (i.e., demonstrating its need to secure its identity in international politics), Prussia effectively expanded without opposition. An analysis of Prussia's expansion in 1864 demonstrates how legitimation strategies prevented the creation of a balancing coalition.
Linkage Diplomacy: Economic and Security Bargaining in the Anglo-Japanese Alliance, 1902–23
Authors: Davis Christina L.
Published: January 2009

How do states use economic-security linkages in international bargaining? Governments can provide economic benefits as a side payment to reinforce security cooperation and use close security ties as a source of bargaining leverage in economic negotiations. Domestic political pressures, however, may constrain the form of linkage. First, economic side payments are more likely to be chosen in areas that will not harm the key interests of the ruling party. Second, involvement by the legislature pushes governments toward using security ties as bargaining leverage for economic gains. Evidence from negotiations between Britain and Japan during the Anglo-Japanese alliance of 1902 to 1923 supports the constraining role of domestic politics. Economic-security linkages occurred as Britain gave favorable economic treatment to Japan in order to strengthen the alliance. Economic competition between the allies, however, made it difficult for Britain to grant asymmetrical economic benefits. In tariff negotiations where business interests had more influence in the domestic policy process, the alliance was used as leverage to force reciprocity.
Motives for Martyrdom: Al-Qaida, Salafi Jihad, and the Spread of Suicide Attacks
Authors: Moghadam Assaf
Published: January 2009

Suicide missions made their modern debut in 1981. In recent years, however, they have witnessed an unprecedented increase according to several indicators, including number of attacks, number of organizations conducting these attacks, number of countries targeted, and number of victims. Existing explanations, including the occupation and outbidding theses, cannot account for the dramatic increase and spread of suicide attacks. A combination of quantitative and qualitative methods, including analysis of a data set of 1,857 suicide attacks from December 1981 through March 2008, suggests that two interrelated factors have contributed to the “globalization of martyrdom”: al-Qaida's evolution into a global terrorist actor and the growing appeal of its guiding ideology, Salafi jihad. As localized patterns of suicide missions have given way to more globalized patterns, states must rethink their counterterrorism strategies. At the same time, because Salafi jihadist groups tend to target Muslims, moderate Muslims and nonviolent Salafists must take the lead in challenging these groups.
Genesis of Tropical Storm Eugene (2005) from Merging Vortices Associated with ITCZ Breakdowns. Part II: Roles of Vortex Merger and Ambient Potential Vorticity
Authors: Kieu Chanh Q. , Zhang Da-Lin
Published: January 2009

In this study, the roles of merging midlevel mesoscale convective vortices (MCVs) and convectively generated potential vorticity (PV) patches embedded in the intertropical convergence zone (ITCZ) in determining tropical cyclogenesis are examined by calculating PV and absolute vorticity budgets with a cloud-resolving simulation of Tropical Storm Eugene (2005). Results show that the vortex merger occurs as the gradual capture of small-scale PV patches within a slow-drifting MCV by another fast-moving MCV, thus concentrating high PV near the merger’s circulation center, with its peak amplitude located slightly above the melting level. The merging phase is characterized by sharp increases in surface heat fluxes, low-level convergence, latent heat release (and upward motion), lower tropospheric PV, surface pressure falls, and growth of cyclonic vorticity from the bottom upward. Melting and freezing appear to affect markedly the vertical structures of diabatic heating, convergence, absolute vorticity, and PV, as well the production of PV during the life cycle of Eugene. Results also show significant contributions of the horizontal vorticity to the magnitude of PV and its production within the storm.

The storm-scale PV budgets show that the above-mentioned amplification of PV results partly from the net internal dynamical forcing between the PV condensing and diabatic production and partly from the continuous lateral PV fluxes from the ITCZ. Without the latter, Eugene would likely be shorter lived after the merger under the influence of intense vertical shear and colder sea surface temperatures. The vorticity budget reveals that the storm-scale rotational growth occurs in the deep troposphere as a result of the increased flux convergence of absolute vorticity during the merging phase. Unlike the previously hypothesized downward growth associated with merging MCVs, the most rapid growth rate is found in the bottom layers of the merger because of the frictional convergence. It is concluded that tropical cyclogenesis from merging MCVs occurs from the bottom upward.
Atlantic Subtropical Storms. Part II: Climatology
Authors: Guishard Mark P. , Evans Jenni L. , Hart Robert E.
Published: January 2009

A 45-yr climatology of subtropical cyclones (ST) for the North Atlantic is presented and analyzed. The STs pose a warm-season forecasting problem for subtropical locations such as Bermuda and the southern United States because of the potentially rapid onset of gale-force winds close to land. Criteria for identification of ST have been developed based on an accompanying case-study analysis. These criteria are applied here to the 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) to construct a consistent historical database of 197 North Atlantic ST in 45 yr.

Because ST may eventually evolve into tropical cyclones, sea surface temperatures (SST) and vertical wind shear conditions for tropical cyclogenesis are contrasted with the conditions for ST genesis identified here. Around 60% of the 197 ST formed over SST in excess of 25°C in a region of weak static stability. Further, the mean environmental vertical wind shear at formation for these storms is 10.7 m s−1, a magnitude generally considered to be unfavorable for tropical cyclogenesis.

The STs have hybrid structure, so the potential for baroclinic and thermodynamic development is explored through the baroclinic zone (characterized by the Eady growth rate σ) and SST field. Seasonal evolution in the location and frequency of ST formation in the basin is demonstrated to correspond well to the changing region of overlap between SST > 25°C and σ > 0.1 day−1.

This climatology is contrasted with two alternative ST datasets. The STs contribute to 12% of tropical cyclones (TC) in the current National Hurricane Center (NHC) Hurricane Database (HURDAT); this equivalent to about 1 in 8 genesis events from an incipient ST disturbance. However, with the addition of 144 ST that are newly identified in this climatology (and not presently in HURDAT) and the reclassification (as not ST) of 65 existing storms in HURDAT, 197/597 storms (33%) in the newly combined database are ST, which emphasizes the potential importance of these warm-season storms.
Linking the Pacific Meridional Mode to ENSO: Coupled Model Analysis
Authors: Zhang Li , Chang Ping , Ji Link
Published: January 2009

The occurrence of a boreal spring phenomenon referred to as the Pacific meridional model (MM) is shown to be intimately linked to the development of El Niño–Southern Oscillation (ENSO) in a long simulation of a coupled model. The MM, characterized by an anomalous north–south SST gradient and anomalous surface circulation in the northeasterly trade regime with maximum variance in boreal spring, is shown to be inherent to thermodynamic ocean–atmosphere coupling in the intertropical convergence zone (ITCZ) latitude, and the MM existence is independent of ENSO. The thermodynamic coupling enhances the persistence of the anomalous winds in the deep tropics, forcing energetic equatorially trapped oceanic waves to occur in the central western Pacific, which in turn initiate an ENSO event. The majority of ENSO events in both nature and the coupled model are preceded by MM events.
An Analysis of Tropical Ocean Diurnal Warm Layers
Authors: Bellenger Hugo , Duvel Jean-Philippe
Published: January 2009

During periods of light surface wind, a warm stable layer forms at the ocean surface with a maximum sea surface temperature (SST) in the early afternoon. The diurnal SST amplitude (DSA) associated with these diurnal warm layers (DWLs) can reach several degrees and impact the tropical climate variability. This paper first presents an approach to building a daily time series of the DSA over the tropics between 1979 and 2002. The DSA is computed over 2.5° of latitude–longitude regions using a simple DWL model forced by hourly-interpolated surface radiative and turbulent fluxes given by the 40-yr ECMWF Re-Analysis (ERA-40). One advantage of this approach is the homogeneity of the results given by the relative homogeneity of ERA-40. The approach is validated at the global scale using empirical DWL models reported in the literature and the Surface Velocity Program (SVP) drifters of the Marine Environmental Data Service (MEDS). For the SVP dataset, a new technique is introduced to derive the diurnal variation of the temperature from raw measurements.

This DWL time series is used to analyze the potential role of DWLs in the variability of the tropical climate. The perturbation of the surface fluxes by DWLs can give a cooling of the ocean mixed layer as large as 2.5 K yr−1 in some tropical regions. On a daily basis, this flux perturbation is often above 10 W m−2 and sometimes exceeds 50 W m−2. DWLs can be organized on regions up to a few thousand kilometers and can persist for more than 5 days. It is shown that strong DWLs develop above the equatorial Indian Ocean during the suppressed phase of the intraseasonal oscillation (ISO). DWLs may trigger large-scale convective events and favor the eastward propagation of the ISO convective perturbation during boreal winter. This study also suggests that the simple approach presented here may be used as a DWL parameterization for atmospheric general circulation models.
Correcting Unintended Perturbation Biases in Hydrologic Data Assimilation
Authors: Ryu Dongryeol , Crow Wade T. , Zhan Xiwu , Jackson Thomas J.
Published: January 2009

Hydrologic data assimilation has become an important tool for improving hydrologic model predictions by using observations from ground, aircraft, and satellite sensors. Among existing data assimilation methods, the ensemble Kalman filter (EnKF) provides a robust framework for optimally updating nonlinear model predictions using observations. In the EnKF, background prediction uncertainty is obtained using a Monte Carlo approach where state variables, parameters, and forcing data for the model are synthetically perturbed to explicitly simulate the error-prone representation of hydrologic processes in the model. However, it is shown here that, owing to the nonlinear nature of these processes, an ensemble of model forecasts perturbed by mean-zero Gaussian noise can produce biased background predictions. This ensemble perturbation bias in soil moisture states can lead to significant mass balance errors and degrade the performance of the EnKF analysis in deeper soil layers. Here, a simple method of bias correction is introduced in which such perturbation bias is corrected using an unperturbed model simulation run in parallel with the EnKF analysis. The proposed bias-correction scheme effectively removes biases in soil moisture and reduces soil water mass balance errors. The performance of the EnKF is improved in deeper layers when the filter is applied with the bias-correction scheme. The interplay of nonlinear hydrologic processes is discussed in the context of perturbation biases, and implications of the bias correction for real-data assimilation cases are presented.
Validation of a Dual-Pass Microwave Land Data Assimilation System for Estimating Surface Soil Moisture in Semiarid Regions
Authors: Yang Kun , Koike Toshio , Kaihotsu Ichirow , Qin Jun
Published: January 2009

This study examines the capability of a new microwave land data assimilation system (LDAS) for estimating soil moisture in semiarid regions, where soil moisture is very heterogeneous. This system assimilates the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) 6.9- and 18.7-GHz brightness temperatures into a land surface model (LSM), with a radiative transfer model as an observation operator. To reduce errors caused by uncertainties of system parameters, the LDAS uses a dual-pass assimilation algorithm, with a calibration pass to estimate major model parameters from satellite data and an assimilation pass to estimate the near-surface soil moisture. Validation data of soil moisture were collected in a Mongolian semiarid region. Results show that (i) the LDAS-estimated soil moistures are comparable to areal averages of in situ measurements, though the measured soil moistures were highly variable from site to site; (ii) the LSM-simulated soil moistures show less biases when the LSM uses LDAS-calibrated parameter values instead of default parameter values, indicating that the satellite-based calibration does contribute to soil moisture estimations; and (iii) compared to the LSM, the LDAS produces more robust and reliable soil moisture when forcing data become worse. The lower sensitivity of the LDAS output to precipitation is particularly encouraging for applying this system to regions where precipitation data are prone to errors.
Nonstationary Westward Translation of Nonlinear Frontal Warm-Core Eddies
Authors: Rubino Angelo , Dotsenko Sergey , Brandt Peter
Published: January 2009

For the first time, an analytical theory and a very high-resolution, frontal numerical model, both based on the unsteady, nonlinear, reduced-gravity shallow water equations on a β plane, have been used to investigate aspects of the migration of homogeneous surface, frontal warm-core eddies on a β plane. Under the assumption that, initially, such vortices are surface circular anticyclones of paraboloidal shape and having both radial and azimuthal velocities that are linearly dependent on the radial coordinate (i.e., circular pulsons of the first order), approximate analytical expressions are found that describe the nonstationary trajectories of their centers of mass for an initial stage as well as for a mature stage of their westward migration. In particular, near-inertial oscillations are evident in the initial migration stage, whose amplitude linearly increases with time, as a result of the unbalanced vortex initial state on a β plane. Such an initial amplification of the vortex oscillations is actually found in the first stage of the evolution of warm-core frontal eddies simulated numerically by means of a frontal numerical model initialized using the shape and velocity fields of circular pulsons of the first order. In the numerical simulations, this stage is followed by an adjusted, complex nonstationary state characterized by a noticeable asymmetry in the meridional component of the vortex’s horizontal pressure gradient, which develops to compensate for the variations of the Coriolis parameter with latitude. Accordingly, the location of the simulated vortex’s maximum depth is always found poleward of the location of the simulated vortex’s center of mass. Moreover, during the adjusted stage, near-inertial oscillations emerge that largely deviate from the exactly inertial ones characterizing analytical circular pulsons: a superinertial and a subinertial oscillation in fact appear, and their frequency difference is found to be an increasing function of latitude. A comparison between vortex westward drifts simulated numerically at different latitudes for different vortex radii and pulsation strengths and the corresponding drifts obtained using existing formulas shows that, initially, the simulated vortex drifts correspond to the fastest predicted ones in many realistic cases. As time elapses, however, the development of a β-adjusted vortex structure, together with the effects of numerical dissipation, tend to slow down the simulated vortex drift.
Role of Eddy Forcing in the Dynamics of Multiple Zonal Jets in a Model of the North Atlantic
Authors: Kamenkovich Igor , Berloff Pavel , Pedlosky Joseph
Published: January 2009

Multiple zonal jets are observed in satellite data–based estimates of oceanic velocities, float measurements, and high-resolution numerical simulations of the ocean circulation. This study makes a step toward understanding the dynamics of these jets in the real ocean by analyzing the vertical structure and dynamical balances within multiple zonal jets simulated in an eddy-resolving primitive equation model of the North Atlantic. In particular, the authors focus on the role of eddy flux convergences (“eddy forcing”) in supporting the buoyancy and relative/potential vorticity (PV) anomalies associated with the jets. The results suggest a central role of baroclinic eddies in the barotropic and baroclinic dynamics of the jets, and significant differences in the effects of eddy forcing between the subtropical and subpolar gyres. Additionally, diabatic potential vorticity sources and sinks, associated with vertical diffusion, are shown to play an important role in supporting the potential vorticity anomalies. The resulting potential vorticity profile does not resemble a “PV staircase”—a distinct meridional structure observed in some idealized studies of geostrophic turbulence.
A New Technique for Estimation of Lower-Tropospheric Temperature and Water Vapor Profiles from Radio Occultation Refractivity
Authors: Jagadheesha D. , Simon B. , Pal P-K. , Joshi P. C. , Maheshwari A.
Published: January 2009

An empirical technique is proposed to obtain temperature and humidity profiles over the tropics using radio occultation refractivity profiles and surface/available lower-altitude temperature and pressure measurements over humid tropical regions. The technique is tested on a large number of diverse radiosonde-derived refractivity profiles over the tropics (30°S–30°N) and selected Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation refractivity profiles that have collocated radiosonde observations over the region 10°S–30°N during the boreal summer of 2006. In a number of cases, the results were in good agreement with the collocated radiosonde data. The error statistics of temperature and humidity profiles obtained from the proposed technique are discussed and compared with the previously published results from another technique and also with the results of a one-dimensional variational data assimilation (1DVAR) technique given with COSMIC data. It is found that the previously published results and proposed technique are marginally better (worse) in reproducing observed relative humidity (specific humidity) when compared to the 1DVAR technique. The proposed new technique is applied on COSMIC refractivity profiles over the Bay of Bengal during summer 2007 to derive changes in vertical thermal and moisture changes in the troposphere between active and break phases of the monsoon pattern and many of the observed features are captured reasonably well.
Impact of Transport Schemes on Modeled Dust Concentrations
Authors: Vuolo Maria Raffaella , Menut Laurent , Chepfer Hélène
Published: January 2009

A sensitivity study is performed with the CHIMERE-DUST chemistry transport model in order to evaluate the modeled mineral dust spread due to the horizontal transport scheme accuracy. Three different schemes are implemented in the model: the simple first-order UPWIND scheme, the second-order Van Leer scheme, and the third-order parabolic piecewise method (PPM) scheme. The results showed that a large part of the uncertainty in dust modeling may be due to the transport scheme only. Compared to the PPM scheme, it is shown that, over a large domain encompassing western Africa and the North Atlantic, a significant increase in the dust plume extension is locally diagnosed (+25% with Van Leer and +48% with UPWIND) and linked to a decrease in the dust maxima (−17% with Van Leer and −32% with UPWIND) to PPM. Far from the sources, hourly surface concentration differences may be up to 30 μg m−3 in Europe, highlighting the high uncertainty of dust modeling for air quality use.
Notes on Temperature-Dependent Lidar Equations
Authors: Adam Mariana
Published: January 2009

The temperature dependence of molecular backscatter coefficients must be taken into account when narrowband interference filters are used in lidar measurements. Thus, the spectral backscatter differential cross section of the molecules involved in the backscattering of the radiation has to be calculated or measured and the interference filter transmission efficiency must be known. The present paper is intended to describe in an easily reproducible manner the procedure involved in calculating the temperature-dependent functions introduced in the lidar equations, including the computation of the differential cross sections for air, nitrogen, and water vapor. The temperature-dependent functions are computed for the Howard University Raman lidar (HURL). The interference filter efficiencies are given by the manufacturer. Error estimates in water vapor mixing ratio and aerosol backscatter ratio involved when temperature-dependent functions are omitted are given for measurements taken with HURL. For the data analyzed, it is found that errors in estimating the water vapor mixing ratio are up to ∼6% while in estimating the aerosol backscattering ratio the errors are up to ∼1.3% in the planetary boundary layer and ∼2.2% in cirrus clouds. Theoretical computations are performed to determine temperature-dependent functions for nitrogen, water vapor, and their ratio, using simulated Gaussian-shaped filters. The goal is to find the optimum combination of different filters that will determine the ratio profiles of the temperature-dependent functions that are either the closest to unity or the least variable. The analyses reveal that quite constant profiles can be obtained for several combinations of the filters.
A Microdrop Generator for the Calibration of a Water Vapor Isotope Ratio Spectrometer
Authors: Iannone Rosario Q. , Romanini Daniele , Kassi Samir , Meijer Harro A. J. , Kerstel Erik R. Th
Published: January 2009

A microdrop generator is described that produces water vapor with a known isotopic composition and volume mixing ratio for the calibration of a near-infrared diode laser water isotope ratio spectrometer. The spectrometer is designed to measure in situ the water vapor deuterium and oxygen (17O and 18O) isotope ratios from the low troposphere up to the lower stratosphere with a high temporal resolution, and is based on ultrasensitive optical-feedback cavity-enhanced absorption spectroscopy.

To calibrate the spectrometer, a commercial microdrop generator (Microdrop GmbH) is used to inject water droplets of known size at a preset repetition frequency into a stream of dry nitrogen or synthetic air. Complete evaporation of the small droplets ensures that there is no isotopic fractionation between the liquid phase and the generated moist “air.” The water mixing ratio of the synthetic air is controlled by the repetition rate and gas flow.

The current system spans a water mixing ratio range from about 10 to 5000 ppmv, representing the range of conditions expected in the lower to upper troposphere. Both lower and higher mixing ratios can be produced after small modifications to the injector’s operating conditions or the system’s design.
Four Years of Tropical ERA-40 Vorticity Maxima Tracks. Part II: Differences between Developing and Nondeveloping Disturbances
Authors: Kerns Brandon , Zipser Edward
Published: January 2009

Using a subset of the relative vorticity maxima (VM) tracks described in Part I, large-scale environmental fields, cold cloud area, and rainfall area are used to discriminate between developing and nondeveloping tropical disturbances in the eastern North Pacific (EPAC) and Atlantic Oceans. By using a minimum cold cloud coverage requirement, the nondeveloping VM are limited to disturbances with enhanced low-level relative vorticity and widespread deep convection. Linear discriminant analysis is used to determine the overall discrimination and the relative importance of each predictor for each basin separately. It is important to distinguish the two basins because, for many predictors, the differences between the basins are greater than the differences between developing and nondeveloping VM in each basin. Using the parametric forecast method, there is greater discrimination and prediction skill in the EPAC than in the Atlantic. There are also significant differences between the two basins in terms of the degree of discrimination provided by each of the predictors. Surprisingly, the mean vertical wind shear magnitude is greater for EPAC developing VM than for EPAC nondeveloping VM. Incorporating the satellite-derived predictors marginally improves the potential forecast skill in the EPAC but not in the Atlantic. The prediction skill (Heidke skill score) of tropical cyclogenesis in the Atlantic is similar to what has been obtained in previous studies using cloud cluster tracks. There is greater predictive skill in the EPAC.
Explicit Two-Step Peer Methods for the Compressible Euler Equations
Authors: Jebens Stefan , Knoth Oswald , Weiner Rüdiger
Published: January 2009

A new time-splitting method for the integration of the compressible Euler equations is presented. It is based on a two-step peer method, which is a general linear method with second-order accuracy in every stage. The scheme uses a computationally very efficient forward–backward scheme for the integration of the high-frequency acoustic modes. With this splitting approach it is possible to stably integrate the compressible Euler equations without any artificial damping. The peer method is tested with the dry Euler equations and a comparison with the common split-explicit second-order three-stage Runge–Kutta method by Wicker and Skamarock shows the potential of the class of peer methods with respect to computational efficiency, stability, and accuracy.
Radar and Profiler Analysis of Colliding Boundaries: A Case Study
Authors: Karan Haldun , Knupp Kevin
Published: January 2009

The kinematics of a head-on collision between two gust fronts, followed by a secondary collision between a third gust front and a bore generated by the initial collision, are described using analyses of Weather Surveillance Radar-1988 Doppler (WSR-88D) and Mobile Integrated Profiling System (MIPS) data. Each gust front involved in the initial collision exhibited a nearly north–south orientation and an east–west movement. The eastward-moving boundary was 2°C colder and moved 7 m s−1 faster than the westward-moving boundary. Two-dimensional wind retrievals reveal contrasting flows within each gravity current. One exhibited a typical gravity current flow structure, while the other assumed the form of a gravity wave/current hybrid with multiple vortices atop the outflow. One of the after-collision boundaries exhibited multiple radar finelines resembling a solitary wave shortly after the collision. About 1 h after the initial collision, a vigorous gust front intersected the eastward-moving bore several minutes before both circulations were sampled by the MIPS. The MIPS measurements indicate that the gust front displaced the bore upward into a neutral residual layer. The bore apparently propagated upward even farther to the next stable layer between 2 and 3 km AGL. MIPS measurements show that the elevated turbulent bore consisted of an initial vigorous wave, with updraft/downdraft magnitudes of 3 and −6 m s−1, respectively, followed by several (elevated) waves of decreasing amplitude.
Understanding the Relationship Between Christian Orthodoxy and Environmentalism
Authors: Truelove Heather Barnes , Joireman Jeff
Published: January 2009

The present study evaluated the hypothesis that people who strongly adhere to Christian orthodoxy may be less proenvironmental to the extent that they are less aware of the biospheric consequences of environmental problems (biospheric AC) but that they may be more proenvironmental than others to the extent that they are more aware of the egoistic and social-altruistic consequences of environmental problems (egoistic AC and social-altruistic AC, respectively). College students ( N = 192) completed measures of awareness of negative consequences (AC), Christian orthodoxy, and environmental behavior. Results showed that Christian orthodoxy negatively related to all measures of environmental behavior. Additionally, biospheric AC was a complete mediator in Christian orthodoxy’s relationships with environmental intentions and willingness to pay for environmental protection and was a partial mediator in Christian orthodoxy’s relationship with proenvironmental political behavior. Neither egoistic AC nor social-altruistic AC correlated with Christian orthodoxy, so their mediating properties were not assessed. Theoretical and practical implications are discussed.
Structure and Compression Behavior of Macro-composite Starch Foams
Authors: Kang Yong-Gang , Song Jim
Published: January 2009

Using a method known as regular packing and stacking (RPS) technology, starch foams made by extrusion foaming of wheat flour can be converted by self-adhesion to produce bulk foams of any required sizes for much more broad applications. These block foams are reinforced by a network of the bonding interfaces and hence can be regarded as macrocomposites. The influence of the reinforcing interfaces on compression behavior of the RPS blocks was investigated by mechanical testing of foams with different geometry of the interface network and interface thickness. It is demonstrated that the interface network of the block foams can be designed to manipulate the macrostructure and compression behavior of the foam for protective packaging.
Environmentally Compatible Foamed Articles Based on Potato Starch, Corn Fiber, and Poly(Vinyl Alcohol)
Authors: Chiellini E. , Cinelli P. , Ilieva V.I. , Imam S.H. , Lawton J.W.
Published: January 2009

Potato starch foam trays based on blends of poly(vinyl alcohol) and corn fibers (CFs), co-product of the corn-wheat wet-milling process, are prepared by baking the blended mixtures in a preheated mold. Materials are evaluated for processing parameters, foam strength, flexibility, and water resistance as a function of fibers content. Addition of CF in formulations improved not only moisture resistance of foam, but has a potential to lower the overall cost of the foamed materials substantially. Interestingly, addition of up to 45% fiber in formulations was possible without compromising the foaming process. Degradability is evaluated both in compost than simulating a disposal in the environment (soil burying and soil surface). Trays are biodegraded within 30—60 days in compost and soil. Particularly, trays containing starch and fiber degraded at much faster rates than trays prepared using starch without natural fillers.
Processing and Properties of Expanded Starch Materials
Authors: Sjöqvist Mia , Boldizar Antal , Rigdahl Mikael
Published: January 2009

Expanded starch materials are prepared from normal potato starch (NPS) and amylopectin potato starch (PAP) using two-step extrusion with an intermediate conditioning in order to control the moisture content. The moisture content is the driving force for the expansion during the second extrusion. The effect of two different plasticizers, urea and glycerol, are compared with regard to the foaming ability in the presence of wheat gluten, acting as a processing aid. Melt strength, moisture content, and elongation at break of the melt of the starch materials prior to expansion are evaluated. The expanded structures are characterized using environmental scanning electron microscopy and density measurements. The water absorption capability of the starch-based foams is also investigated. The processing of starch is facilitated by the addition of gluten and the properties of the foam are improved. The fraction of small cells in the foams is increased and the foam exhibits an improved water absorption ability. PAP in this case is found to be a more suitable raw material than NPS for preparing starch-based foams.
Disability Prototypes in the United States and the Russian Federation:An International Comparison
Authors: Martz Erin , Strohmer Douglas , Fitzgerald Debra , Daniel Samantha , Arm Jennifer
Published: January 2009

The purpose of this cross-cultural research is to examine prototypical perspectives about disability groups in the United States and Russia by extending the research on disability prototypes that was conducted by McCaughey and Strohmer. Open-ended questions permitted participants to describe what they thought were prototypical characteristics of people in three disability groups (AIDS, hearing impairment, and spinal cord injury). A series of chi-square analyses indicate that there are significant differences across superordinate categories between the two countries, in addition to significant differences within two superordinate categories when examining the two samples across three disability categories.Tentative conclusions of the findings, possible implications for rehabilitation counselors, and directions for further research are briefly discussed.
The Realist Approach to Explanatory Mechanisms in Social Science
Authors: Demetriou Chares
Published: January 2009

The mechanism-realist paradigm in the philosophy of science, championed by Mario Bunge and Roy Bhaskar, sets certain expectations for the substantive social-scientific application of the paradigm. To evaluate the application of the paradigm in accomplished substantive research, as well as the potential for future research, I examine the work of Charles Tilly, the exemplary substantive work in the mechanism-realist tradition. Based on this examination, I argue for the usefulness of explanatory mechanisms, provided that they are couched in terms of a heuristic. Such a position is the most reasonable one to adopt given the expectations set by the paradigm in relation to complexity stemming from mechanism interaction and to a notion of causality that is deeper than that acknowledged by empiricism and positivism.
Troubles with Stereotypes for Spinozan minds
Authors: Huebner Bryce
Published: January 2009

Some people succeed in adopting feminist ideals in spite of the prevalence of asymmetric power relations. However, those who adopt such ideals face a number of psychological difficulties in inhibiting stereotype-based judgments. I argue that a Spinozan theory of belief fixation offers a more complete understanding of the mechanisms that underwrite our intuitive stereotype-based judgments. I also argue that a Spinozan theory of belief fixation offers resources for avoiding stereotype-based judgments where they are antecedently recognized to be pernicious and insidious.
The Influence of Discrimination and Fairness on Collective Self-Esteem
Authors: Scheepers Daan , Spears Russell , Manstead Antony S. R. , Doosje Bertjan
Published: January 2009

This article examines the influence of discrimination and fairness on collective self-esteem. Whereas social identity theory's self-esteem hypothesis emphasizes that discrimination can enhance self-esteem, the authors contend that this self-esteem advantage will actually reverse when groups are primed with the idea of engaging in a fair intergroup competition. They measured (Study 1) and manipulated (Study 2) discrimination and fairness in real (Study 1) and minimal (Study 2) groups, after which they manipulated the presence of an intergroup competition in both studies. Collective self-esteem served as the main dependent measure. Results indicated that when an intergroup competition was present or impending, previously expressed fairness (or less discrimination) was positively related to self-esteem, whereas discrimination was positively related to collective self-esteem in the absence of an intergroup competition. Results are discussed in terms of social identity theory and the importance of the broader social context for examining the relationship between discrimination and self-esteem.