bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodynamic Activation of β-Catenin and T-Cell-Specific Transcription Factor Signaling in Vascular Endothelium Regulates Fibronectin Expression
Authors: Gelfand Bradley D. , Meller Julia , Pryor Andrew W. , Kahn Michael , Bortz Pamela D. Schoppee , Wamhoff Brian R. , Blackman Brett R.
Published: April 2011

Objective—

The goal of this study was to assess the activity of β-catenin/T-cell-specific transcription factor (TCF) signaling in atherosclerosis development and its regulation of fibronectin in vascular endothelium.

Methods and Results—

Histological staining identified preferential nuclear localization of β-catenin in the endothelium of atheroprone aorta before and during lesion development. Transgenic reporter studies revealed that increased levels of TCF transcriptional activity in endothelium correlated anatomically with β-catenin nuclear localization and fibronectin deposition. Exposure of endothelial cells to human-derived atheroprone shear stress induced nuclear localization of β-catenin, transcriptional activation of TCF, and expression of fibronectin. Activation of fibronectin expression required β-catenin, TCF, and the transcriptional coactivator CRBP-binding protein. Finally, we identified platelet endothelial cell adhesion molecule-1 as a critical regulator of constitutive β-catenin and glycogen synthase kinase-3β activities.

Conclusion—

These data reveal novel constitutive activation of the endothelial β-catenin/TCF signaling pathway in atherosclerosis and regulation of fibronectin through hemodynamic shear stress.
Phosphatase-Resistant Gap Junctions Inhibit Pathological Remodeling and Prevent Arrhythmias
Authors: Remo Benjamin F. , Qu Jiaxiang , Volpicelli Frank M. , Giovannone Steven , Shin Daniel , Lader Joshua , Liu Fang-yu , Zhang Jie , Lent Danielle S. , Morley Gregory E. , Fishman Glenn I.
Published: April 2011

Rationale:

Posttranslational phosphorylation of connexin43 (Cx43) has been proposed as a key regulatory event in normal cardiac gap junction expression and pathological gap junction remodeling. Nonetheless, the role of Cx43 phosphorylation in the context of the intact organism is poorly understood.

Objective:

To establish whether specific Cx43 phosphorylation events influence gap junction expression and pathological remodeling.

Methods and Results:

We generated Cx43 germline knock-in mice in which serines 325/328/330 were replaced with phosphomimetic glutamic acids (S3E) or nonphosphorylatable alanines (S3A). The S3E mice were resistant to acute and chronic pathological gap junction remodeling and displayed diminished susceptibility to the induction of ventricular arrhythmias. Conversely, the S3A mice showed deleterious effects on cardiac gap junction formation and function, developed electric remodeling, and were highly susceptible to inducible arrhythmias.

Conclusions:

These data demonstrate a mechanistic link between posttranslational phosphorylation of Cx43 and gap junction formation, remodeling, and arrhythmic susceptibility.
Molecular Pathophysiology of Cerebral Hemorrhage
Authors: Aronowski Jaroslaw , Zhao Xiurong
Published: April 2011

Intracerebral hemorrhage (ICH) is an often fatal type of stroke that kills ≈30 000 people annually in the United States. If the patient survives the ictus, then the resulting hematoma within brain parenchyma triggers a series of adverse events causing secondary insults and severe neurological deficits. This article discusses selected aspects of secondary brain injury after ICH and outlines key mechanisms associated with hematoma toxicity, oxidative stress, and inflammation. Finally, this review discusses the relevance of hematoma resolution processes as a target for ICH therapy and presents potential clinically relevant molecular targets that could be harnessed to treat secondary injury associated with ICH injury.
Heart Rate Contributes to the Vascular Effects of Chronic Mental Stress
Authors: Custodis Florian , Gertz Karen , Balkaya Mustafa , Prinz Vincent , Mathar Ilka , Stamm Christoph , Kronenberg Golo , Kazakov Andrey , Freichel Marc , Böhm Michael , Endres Matthias , Laufs Ulrich
Published: April 2011

Background and Purpose—

Vascular effects of mental stress are only partially understood. Therefore, we studied effects of chronic stress and heart rate (HR) on endothelial function and cerebral ischemia.

Methods—

129S6/SvEv mice were randomized to the I(
f
)-channel inhibitor ivabradine (10 mg/kg per day) or vehicle and underwent a chronic stress protocol for 28 days.

Results—

Stress increased HR from 514±10 bpm to 570±14 bpm, this was prevented by ivabradine (485±7 bpm). Endothelium-dependent relaxation of aortic rings was impaired in mice exposed to stress. HR reduction restored endothelial function to the level of naive controls. Vascular lipid hydroperoxides were increased to 333%±24% and vascular NADPH oxidase activity was upregulated to 223±38% in stressed mice, which was prevented by ivabradine. Stress reduced aortic endothelial nitric oxide synthase mRNA expression to 84%±3% and increased AT1 receptor mRNA to 168%±18%. Both effects were attenuated by HR reduction. In brain tissue, stress resulted in an upregulation of lipid hydroperoxides to 140%±11%, which was attenuated by HR reduction. Ivabradine increased brain capillary density in naive and in stressed mice. Mice exposed to chronic stress before induction of ischemic stroke by transient middle cerebral artery occlusion exhibited increased lesion size (33.7±2.3 mm
3
versus 23.9±2.4 mm
3
). HR reduction led to a marked reduction of the infarct volume to 12.9±3.3 mm
3
.

Conclusions—

Chronic stress impairs endothelial function and aggravates ischemic brain injury. HR reduction protects from cerebral ischemia via improvement of endothelial function and reduction of oxidative stress. These results identify heart rate as a mediator of vascular effects induced by chronic stress.
Does Impaired Cerebrovascular Reactivity Predict Stroke Risk in Asymptomatic Carotid Stenosis?
Authors: King Alice , Serena Joaquin , Bornstein Natan M. , Markus Hugh S.
Published: April 2011

Background and Purpose—

Improved methods are required to identify the subgroup of patients with asymptomatic carotid stenosis who will have stroke develop. It has been suggested that impaired cerebral reactivity (CVR) may predict high risk, but no multicenter studies have examined this.

Methods—

In a preplanned substudy of Asymptomatic Carotid Emboli Study, 106 patients were recruited with ≥70% asymptomatic carotid stenosis. Transcranial Doppler was used to measure CVR with a vasodilatory response of carbon dioxide or acetazolamide. A meta-analysis of the data with previously published studies was performed.

Results—

Thirty-two of 106 (30.2%) had severely impaired CVR ipsilateral to the study artery. Mean follow-up was 680 days. There were no ipsilateral strokes. There was a nonsignificant trend to more secondary end points of any stroke/TIA in patients with severely impaired CVR. Three of 32 (9.4%) had impaired CVR compared with 2 of 74 (2.7%) without (hazard ratio, 2.54; 95% CI, 0.61–21.74;
P
=0.158). On meta-analysis of the Asymptomatic Carotid Emboli Study data with previous studies, impaired CVR was associated with increased risk of ipsilateral stroke alone (OR, 6.14; 95% CI, 1.27–29.5;
P
=0.02), ipsilateral stroke or TIA (OR, 4.76; 95% CI, 1.86–12.16;
P
=0.001), and any stroke (OR, 4.66; 95% CI, 1.69–12.85;
P
=0.003).

Conclusions—

In this international multicenter study, we found no association between impaired CVR and recurrent events, but the study was underpowered because of the low event rate. Meta-analysis of available data suggested an association between impaired CVR and future risk. However, currently there are insufficient data to justify the routine clinical use of CVR to stratify risk in patients with asymptomatic carotid stenosis for selection for carotid endarterectomy.
A Daring Hospitality:Towards a Poetics of Time
Authors: Amato Andy
Published: April 2011

The aim of this paper is to approach an understanding of time through the concept of “poetic time,” and to do so by exploring the connections between theorizing, creativity, and ethics. Poetic time, in this sense, is a subjective phenomenon that we experience in our moment-to-moment acceptance of our ethical relationship to others. This acceptance is enacted by the decision to share our own allotment of time—our finite amount of time—with others, and others with us. This sharing of time finds and simultaneously creates spaces of mutuality and moments of poetry; it reveals and constructs worlds of mutuality.
Trends in Precipitable Water and Relative Humidity in China: 1979–2005
Authors: Xie Baoguo , Zhang Qinghong , Ying Yue
Published: April 2011

Annual and seasonal trends of precipitable water (PW) and relative humidity (RH) at 850, 700, and 500 hPa are studied using the data from 106 radiosonde stations over China during the period 1979–2005. Analysis shows evidence of an increase in PW associated with the slight warming observed in the lower to midtroposphere over China. The northern part of China shows a significant upward trend of PW in summer, and drying of the atmosphere in winter is found in most regions over China. Annual and seasonal trends in RH at the 850-, 700-, and 500-hPa levels show no significant trends in most regions in China except for Xinjiang, which shows an upward trend, and central China, where there was a downward trend in RH at 500 hPa. It is found that changes in PW are coincident with the warming of the surface and the lower to midtroposphere. The RH in the lower to midtroposphere in most regions over China has remained steady during the most recent 30 years, as might be expected given the increasing of PW and the warming above the surface. The long-term trend of precipitation over China may be linked to the trends of PW and RH at the lower level and midlevel.
Physics of U.S. Surface Temperature Response to ENSO
Authors: Zhang Tao , Hoerling Martin P. , Perlwitz Judith , Sun De-Zheng , Murray Donald
Published: April 2011

To elucidate physical processes responsible for the response of U.S. surface temperatures to El Niño–Southern Oscillation (ENSO), the surface energy balance is diagnosed from observations, with emphasis on the role of clouds, water vapor, and land surface properties associated with snow cover and soil moisture. Results for the winter season (December–February) indicate that U.S. surface temperature conditions associated with ENSO are determined principally by anomalies in the surface radiative heating—the sum of absorbed solar radiation and downward longwave radiation. Each component of the surface radiative heating is linked with specific characteristics of the atmospheric hydrologic response to ENSO and also to feedbacks by the land surface response. During El Niño, surface warming over the northern United States is physically consistent with three primary processes: 1) increased downward solar radiation due to reduced cloud optical thickness, 2) reduced reflected solar radiation due to an albedo decline resulting from snow cover loss, and 3) increased downward longwave radiation linked to an increase in precipitable water. In contrast, surface cooling over the southern United States during El Niño is mainly the result of a reduction in incoming solar radiation resulting from increased cloud optical thickness. During La Niña, surface warming over the central United States results mainly from snow cover losses, whereas warming over the southern United States results mainly from a reduction in cloud optical thickness that yields increased incoming solar radiation and also from an increase in precipitable water that enhances the downward longwave radiation. For both phases of ENSO the surface radiation budget is closely linked to large-scale horizontal and vertical motions in the free atmosphere through two main processes: 1) the convergence of the atmospheric water vapor transport that largely determines cloud optical thickness and thereby affects incoming shortwave radiation and 2) the changes in tropospheric column temperature resulting from the characteristic atmospheric teleconnections that largely determine column precipitable water and thereby affect downward longwave radiation.
Higher Hydroclimatic Intensity with Global Warming
Authors: Giorgi F. , Im E.-S. , Coppola E. , Diffenbaugh N. S. , Gao X. J. , Mariotti L. , Shi Y.
Published: April 2011

Because of their dependence on water, natural and human systems are highly sensitive to changes in the hydrologic cycle. The authors introduce a new measure of hydroclimatic intensity (HY-INT), which integrates metrics of precipitation intensity and dry spell length, viewing the response of these two metrics to global warming as deeply interconnected. Using a suite of global and regional climate model experiments, it is found that increasing HY-INT is a consistent and ubiquitous signature of twenty-first-century, greenhouse gas–induced global warming. Depending on the region, the increase in HY-INT is due to an increase in precipitation intensity, dry spell length, or both. Late twentieth-century observations also exhibit dominant positive HY-INT trends, providing a hydroclimatic signature of late twentieth-century warming. The authors find that increasing HY-INT is physically consistent with the response of both precipitation intensity and dry spell length to global warming. Precipitation intensity increases because of increased atmospheric water holding capacity. However, increases in mean precipitation are tied to increases in surface evaporation rates, which are lower than for atmospheric moisture. This leads to a reduction in the number of wet days and an increase in dry spell length. This analysis identifies increasing hydroclimatic intensity as a robust integrated response to global warming, implying increasing risks for systems that are sensitive to wet and dry extremes and providing a potential target for detection and attribution of hydroclimatic changes.
Interdecadal Variability of Summer Rainfall in Taiwan Associated with Tropical Cyclones and Monsoon
Authors: Chen Jau-Ming , Chen Hui-Shan
Published: April 2011

This study investigates interdecadal variability of summer (June–August) rainfall in Taiwan for the 1950–2008 period. Summer rainfall in Taiwan is partitioned into two components: tropical cyclone (TC) rainfall caused by TC passage and seasonal monsoon rainfall associated with monsoon southwesterly flows. The joint interdecadal mode of TC rainfall and seasonal monsoon rainfall is extracted by empirical orthogonal function (EOF) analysis. The first interdecadal mode features an increasing trend plus a near-20-yr oscillation. The spatial patterns of this mode are uniform in sign over the entirety of Taiwan with positive anomalies for TC rainfall and negative anomalies for seasonal monsoon rainfall. These results reveal that TC rainfall and seasonal monsoon rainfall tend to vary inversely in interdecadal variability, with a positive trend in TC rainfall and a negative trend in seasonal monsoon rainfall. Large-scale regulating processes associated with this interdecadal rainfall mode are interpreted from the correlation patterns. Significant warm sea surface temperature (SST) anomalies exist in the tropical central and eastern Pacific and the Indian Ocean. At the low levels, an anomalous large-scale divergent center occurs in the Australian regions, which in turn evokes an anomalous cyclonic circulation in the subtropical North Pacific. Taiwan is on its western edge and affected by anomalous northeasterly flows, in company with weakening in the prevailing southwesterly flows and moisture transport from the South China Sea into Taiwan. As such, negative seasonal monsoon rainfall anomalies occur in Taiwan with a decreasing trend. The subtropical anomalous cyclonic circulation also weakens vertical wind shear over the major TC genesis region, that is, the Philippine Sea. Warm SST anomalies in this region and accompanying anomalous ascending motion provide additional favorable conditions for TC genesis. More TCs are thus formed in the Philippine Sea. The appearance of an anomalous cyclonic circulation in the subtropical North Pacific reflects a weakening of the Pacific subtopical high, which tends to retreat eastward and provides southeasterly or southerly flows on its western boundary to guide TCs formed in the Philippine Sea northwestward toward Taiwan. TC frequency and TC rainfall thus increase in Taiwan with an increasing trend.
The Distribution of Cloud Horizontal Sizes
Authors: Wood Robert , Field Paul R.
Published: April 2011

Cloud horizontal size distributions from near-global satellite data, from aircraft, and from a global high-resolution numerical weather prediction model, are presented for the scale range 0.1–8000 km and are shown to be well-represented using a single power-law relationship with an exponent of β = 1.66 ±0.04 from 0.1 to 1500 km or more. At scales longer than 1500 km, there is a statistically significant scale break with fewer very large clouds than expected from the power law. The size distribution is integrated to determine the contribution to cloud cover and visible reflectance from clouds larger than a given size. Globally, clouds with a horizontal dimension of 200 km or more constitute approximately 50% of the cloud cover and 60% of the reflectance, and this result is not sensitive to the minimum size threshold assumed in the integral assuming that the power law can be extrapolated below 100-m scale. The result is also not sensitive to whether the size distribution is determined using cloud segment length or cloud area. This emphasizes the great role played by large cloud sheets in determining the earth’s albedo. On the other hand, some 15% of global cloud cover comes from clouds smaller than 10 km, thus emphasizing the broad range of cloud sizes that contribute significantly to the earth’s radiation budget. Both of these results stem from the fact that β is slightly less than 2. The data are further divided and geographical and seasonal variations in the cloud size L50 for which clouds larger than L50 constitute 50% of the cloud cover are determined. The largest clouds (L50 > 300 km) are found over the midlatitude oceans, particularly in summer, and over the tropical convective regions of the west Pacific and Indian Oceans and the monsoon-influenced landmasses. The smallest clouds (L50 < 100 km) are found over the trade wind regions of the tropics/subtropics and over arid land areas. Small variations in the exponent β contribute significantly to the variations in L50. Finally, it is shown that a bounded cascade model can faithfully simulate the observed cloud size distributions and use this to examine the effects of limiting sensor resolution (pixel size) and domain size (number of pixels across image). Sensor resolution is not found to strongly impact the cloud size distribution provided the ratio of the domain to pixel size remains greater than ~1000. Thus, previous studies with small domain–pixel size ratios may provide biased information about the true cloud size distribution, and should be interpreted with caution.
Atmospheric Moisture Transports from Ocean to Land and Global Energy Flows in Reanalyses
Authors: Trenberth Kevin E. , Fasullo John T. , Mackaro Jessica
Published: April 2011

An assessment is made of the global energy and hydrological cycles from eight current atmospheric reanalyses and their depiction of changes over time. A brief evaluation of the water and energy cycles in the latest version of the NCAR climate model referred to as CCSM4 is also given. The focus is on the mean ocean, land, and global precipitation P; the corresponding evaporation E; their difference corresponding to the surface freshwater flux E–P; and the vertically integrated atmospheric moisture transports. Using the model-based P and E, the time- and area-average E–P for the oceans, P–E for land, and the moisture transport from ocean to land should all be identical but are not close in most reanalyses, and often differ significantly from observational estimates of the surface return flow based on net river discharge into the oceans. Their differences reveal outstanding issues with atmospheric models and their biases, which are manifested as analysis increments in the reanalyses. The NCAR CCSM4, along with most reanalysis models, the exception being MERRA, has too-intense water cycling (P and E) over the ocean although ocean-to-land transports are very close to observed. Precipitation from reanalyses that assimilate moisture from satellite observations exhibits large changes identified with the changes in the observing system, as new and improved temperature and water vapor channels are assimilated and, while P improves after about 2002, E–P does not. Discrepancies among hydrological cycle components arise from analysis increments that can add or subtract moisture. The large-scale moisture budget divergences are more stable in time and similar across reanalyses than model-based estimates of E–P. Results are consistent with the view that recycling of moisture is too large in most models and the lifetime of moisture is too short. For the energy cycle, most reanalyses have spurious imbalances of ~10 W m−2 within the atmosphere, and ~5–10 W m−2 in net fluxes into the surface and to space. Major improvements are needed in model treatment and assimilation of moisture, and surface fluxes from reanalyses should only be used with great caution.
Flooding in Western Washington: The Connection to Atmospheric Rivers*
Authors: Neiman Paul J. , Schick Lawrence J. , Ralph F. Martin , Abel Mimi R. , Wick Gary A.
Published: April 2011

This study utilizes multiple decades of daily streamflow data gathered in four major watersheds in western Washington to determine the meteorological conditions most likely to cause flooding in those watersheds. Two are located in the Olympic Mountains and the other two in the western Cascades; and each has uniquely different topographic characteristics. The flood analysis is based on the maximum daily flow observed during each water year (WY) at each site [i.e., the annual peak daily flow (APDF)], with an initial emphasis on the 12 most recent water years between WY1998 and 2009, and then focusing on a 30-year interval between WY1980 and 2009. The shorter time period coincides with relatively complete passive microwave satellite coverage of integrated water vapor (IWV) over the Pacific basin. The combination of IWV imagery and streamflow data highlights a close link between landfalling atmospheric rivers (ARs) and APDFs (i.e., 46 of the 48 APDFs occurred with landfalling ARs). To complement this approach, the three-decade time series of APDFs, which correspond to the availability of the North American Regional Reanalysis (NARR) dataset, are examined. The APDFs occur most often, and are typically largest in magnitude, from November to January. The NARR is used to assess the composite meteorological conditions associated with the 10 largest APDFs at each site during this 30-year period. Heavy precipitation fell during the top 10 APDFs, and anomalously high composite NARR melting levels averaged ~1.9 km MSL, which is primarily above the four basins of interest. Hence, on average, mostly rain rather than snow fell within these basins, leading to enhanced runoff. The flooding on the four watersheds shared common meteorological attributes, including the presence of landfalling ARs with anomalous warmth, strong low-level water vapor fluxes, and weak static stability. There were also key differences that modulated the orographic control of precipitation. Notably, two watersheds experienced their top 10 APDFs when the low-level flow was southwesterly, while the other two basins had their largest APDFs with west–southwesterly flow. These differences arose because of the region’s complex topography, basin orientations, and related rain shadowing.
Oceanic Rings and Jets as Statistical Equilibrium States
Authors: Venaille Antoine , Bouchet Freddy
Published: April 2011

Equilibrium statistical mechanics of two-dimensional flows provides an explanation and a prediction for the self-organization of large-scale coherent structures. This theory is applied in this paper to the description of oceanic rings and jets, in the framework of a 1.5-layer quasigeostrophic model. The theory predicts the spontaneous formation of regions where the potential vorticity is homogenized, with strong and localized jets at their interface. Mesoscale rings are shown to be close to a statistical equilibrium: the theory accounts for their shape, drift, and ubiquity in the ocean, independently of the underlying generation mechanism. At basin scale, inertial states presenting midbasin eastward jets (and then different from the classical Fofonoff solution) are described as marginally unstable states. In that case, considering a purely inertial limit is a first step toward more comprehensive out-of-equilibrium studies that would take into account other essential aspects, such as wind forcing.
The Origin of Along-Shelf Pressure Gradient in the Middle Atlantic Bight
Authors: Xu F.-H. , Oey L.-Y.
Published: April 2011

It is quite widely accepted that the along-shelf pressure gradient (ASPG) contributes in driving shelf currents in the Middle Atlantic Bight (MAB) off the northeastern U.S. coast; its origin, however, remains a subject for debate. Based on analyses of 16 yr (1993–2008) of satellite, tide gauge, river, and wind data and numerical experiments, the authors suggest that river and Coastal Labrador Sea Water (CLSW) transport contribute to a positive mean ASPG (tilt up northward) in the ratio of approximately 1:7 (i.e., CLSW dominates), whereas wind and the Gulf Stream tend to produce a negative mean ASPG in the ratio of approximately 1:6.

Data also indicate seasonal and interannual variations of ASPG that correlate with the Gulf Stream’s shift and eddy kinetic energy north of the Gulf Stream (N-EKE) due to warm-core rings. A southward shift in the Gulf Stream produces a sea level drop north of Cape Hatteras, which is most rapid in winter. The N-EKE peaks in late spring to early summer and is larger in some years than others. A process model is used to show that ring propagation along the MAB slope and ring impingement upon the shelf break north of Cape Hatteras generate along-isobath density gradients and cross-shelfbreak transports that produce sea level change on the shelf; the dominant ageostrophic term in the depth-integrated vorticity balance is the joint effect of baroclinicity and relief (JEBAR) term. In particular, the shelf’s sea surface slopes down to the north when rings approach Cape Hatteras.
Stress Training Improves Performance During a Stressful Flight
Authors: McClernon Christopher K. , McCauley Michael E. , O’Connor Paul E. , Warm Joel S.
Published: April 2011

Objective: This study investigated whether stress training introduced during the acquisition of simulator-based flight skills enhances pilot performance during subsequent stressful flight operations in an actual aircraft.

Background: Despite knowledge that preconditions to aircraft accidents can be strongly influenced by pilot stress, little is known about the effectiveness of stress training and how it transfers to operational flight settings.

Method: For this study, 30 participants with no flying experience were assigned at random to a stress-trained treatment group or a control group. Stress training consisted of systematic pairing of skill acquisition in a flight simulator with stress coping mechanisms in the presence of a cold pressor. Control participants received identical flight skill acquisition training but without stress training. Participants then performed a stressful flying task in a Piper Archer aircraft.

Results: Stress-trained research participants flew the aircraft more smoothly, as recorded by aircraft telemetry data, and generally better, as recorded by flight instructor evaluations, than did control participants.

Conclusions: Introducing stress coping mechanisms during flight training improved performance in a stressful flying task.

Application: The results of this study indicate that stress training during the acquisition of flight skills may serve to enhance pilot performance in stressful operational flight and, therefore, might mitigate the contribution of pilot stress to aircraft mishaps.
Fluid flow in coat-hanger die of melt blowing process: comparison of numerical simulations and experimental measurements
Authors: Kai Meng  , Xinhou Wang  , Qingguan Chen
Published: April 2011

The coat-hanger die is an important part in the melt blowing process, the performance of which is characterized by the flow uniformity at its outlet. The primary objective of this study is to validate the finite element method applied in the simulation of fluid flow in the coat-hanger die, so as to search for the optimal flow channel geometry based on simulation and optimization algorithms. The fluid flow in the coat-hanger die is simulated through three-dimensional finite element method in this paper. Simulation results are experimentally verified qualitatively and quantitatively using particle image velocimetry. Good agreements are obtained in the flow patterns and velocities calculated at the die outlet, which suggests that the numerical methodology can reliably predict the details of fluid flow in the coat-hanger die.
Subjective Well-Being in Urban, Ethnically Diverse Adolescents The Role of Stress and Coping
Authors: Vera Elizabeth M. , Vacek Kimberly , Blackmon Sha’kema , Coyle Laura , Gomez Kenia , Jorgenson Katherine , Luginbuhl Paula , Moallem Isabel , Steele John C.
Published: April 2011

This study examines stressors, general stress levels, coping strategies, and subjective well-being in a sample of 144 ethnically diverse, urban adolescents (mean age of 13). The most frequently reported stressors include the death of a family member, feeling socially isolated, family financial problems, injury of a family member, and parents arguing. The most common coping strategies are seeking support, acceptance, active coping, using distraction, and venting. Positive and negative affect are related to many coping strategies, but only humor buffered the relationship between stress and negative affect. Venting exacerbates the negative relationship between stress and life satisfaction. Implications for helping ethnically diverse, urban adolescents cope with stressors and maintain well-being are discussed.
Toxic Equine Parkinsonism: An Immunohistochemical Study of 10 Horses With Nigropallidal Encephalomalacia
Authors: Chang H. T. , Rumbeiha W. K. , Patterson J. S. , Puschner B. , Knight A. P.
Published: April 2011

Chronic ingestion of yellow star thistle ( Centaurea solstitialis) or Russian knapweed ( Acroptilon repens) causes nigropallidal encephalomalacia (NPE) in horses with an abrupt onset of neurologic signs characterized by dystonia of lips and tongue, inability to prehend food, depression, and locomotor deficits. The objectives of this study were to reexamine the pathologic alterations of NPE and to conduct an immunohistochemistry study using antibodies to tyrosine hydroxylase and α-synuclein, to determine whether NPE brains show histopathologic features resembling those in human Parkinson disease. Results confirm that the NPE lesions are located within the substantia nigra pars reticulata, sparing the cell bodies of the dopaminergic neurons in the substantia nigra pars compacta, and in the rostral portion of the globus pallidus, with partial disruption of dopaminergic (tyrosine hydroxylase–positive) fibers passing through the globus pallidus. No abnormal cytoplasmic inclusions like the Lewy bodies of human Parkinson disease were seen in these NPE brains. These findings indicate that equine NPE may serve as a large animal model of environmentally acquired toxic parkinsonism, with clinical phenotype directly attributable to lesions in globus pallidus and substantia nigra pars reticulata rather than to the destruction of dopaminergic neurons.
Truly Satisfied With Your Retirement or Just Resigned? Pathways Toward Different Patterns of Retirement Satisfaction
Authors: Potočnik Kristina , Tordera Núria , Peiró José María
Published: April 2011

The main aim of the present study was to explore different patterns of retirement satisfaction. Following the dynamic model of job satisfaction, we identify different retirement satisfaction forms. We also examined a set of antecedents of observed retirement satisfaction forms and their impact on psychological well-being. Using a sample of 270 Spanish retirees, cluster analytical results showed four retirement satisfaction forms. These were stabilized-progressive, resigned-stabilized, and resigned retirement satisfaction and constructive-fixated retirement dissatisfaction. Gender, retirement intentions, and voluntariness of retirement transition predicted retirement satisfaction forms. Finally, our findings showed that participants experiencing constructive-fixated retirement dissatisfaction reported lower psychological well-being compared with participants from stabilized-progressive and resigned-stabilized retirement satisfaction forms. These findings provide preliminary support for the study of retirement satisfaction from the dynamic perspective and call for more research on this issue. The findings could also imply the potential value of attending to retirement transition factors to achieve better adjustment to retirement.
Setting properties and biocompatibility of dicalcium silicate with varying additions of tricalcium aluminate
Authors: Liu Weining , Chang Jiang
Published: April 2011

This study sought to prepare biphasic mixtures by adding tricalcium aluminate (Ca3Al2O6) into dicalcium silicate (Ca2SiO4) and to evaluate the effect of Ca3Al2O6 on setting properties and biocompatibility of the Ca2SiO4/Ca3Al2O6 mixtures as compared to pure Ca2SiO4. The results indicated that the addition of Ca3Al2O6 into Ca2SiO4 reduced the setting time and improved the compressive strength. Furthermore, Ca2SiO4/Ca3Al2O6 mixtures were bioactive and biocompatible, and had a stimulatory effect on the L929 cell growth when the content of Ca3Al2O6 was below 10%. Therefore, the mixtures with 10% Ca3Al2O6 produced the best compromise between setting and in vitro biological properties.
Improved synthesis of hyaluronic acid hydrogel and its effect on tissue augmentation
Authors: Yan Xiang Mei , Seo Moo Seok , Hwang Eui Jin , Cho Il Hwan , Hahn Sei Kwang , Sohn Uy Dong
Published: April 2011

HA–HMDA hydrogels were developed by direct amide bond formation between the carboxyl groups of hyaluronic acid (HA) and hexamethylenediamine (HMDA) with an optimized carboxyl group modification in the preliminary experiment. However, these HA–HMDA hydrogels transformed into an unstable liquid form after steam sterilization, and were problematic for application to actual dermal filler. A new method to overcome the problem of the previously developed HA–HMDA hydrogels is to prepare them by adjusting the pH in this study. Not only are these improved HA–HMDA hydrogels prepared with lower amounts of cross-linking and activation agents compared to the previously developed hydrogels, but they also maintain a stable form after steam sterilization. These improved HA–HMDA hydrogels showed higher viscoelasticity and longer lasting effects than the previous ones, despite the fact that the amount of the HMDA used as a cross-linking agent as well as 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole monohydrated (HOBt) used as activation agents were substantially reduced. According to an in vivo test using a wrinkled mouse model, the improved HA–HMDA hydrogels exhibited significantly improved tissue augmentation effects compared to a positive control of Restylane, which is widely used for the tissue augmentation throughout the world. Furthermore, histological analysis revealed excellent biocompatibility and safety of the improved synthesized HA–HMDA hydrogels.
Binary system thermodynamics to control pore architecture of PCL scaffold via temperature-driven phase separation process
Authors: Guarino Vincenzo , Guaccio Angela , Guarnieri Daniela , Netti Paolo A , Ambrosio Luigi
Published: April 2011

The use of scaffold-aided strategies for the regeneration of biological tissues requires the fulfilment of an accurate architectural design, that is, micro and macrostructure, with the final goal of realizing architectures to adopt as guidance for those cell activities specific to the formation of novel tissues. Here, highly porous scaffolds made up of biodegradable poly(ε-caprolactone) (PCL) have been realized by thermally induced phase separation (TIPS). Two different polymer/solvent systems, derived by the dissolution of PCL in dioxane and DMSO respectively, were investigated. The aim was to demonstrate the high potential of TIPS technique, in imprinting specific pore features to the polymer matrices, by a conscious selection of polymer/solvent systems. The investigation of pore architecture by SEM/mercury intrusion porosimetry/image analyses, firstly allow to detect remarkable variations in porosity (from 92% to 78%,) and pore sizes, ranging from micro-scale ( ca 10 µm) to macro-scale (greater than 100 µm) as a function of the used polymer/solvent systems. Moreover, experimental and theoretical evidences referred to scaffold shaped in custom-made molds – a thin Teflon ring between two copper plates – allow exploring how the sensitivity of polymer solution features (i.e., crystallinity, thermal inertia) to the cooling temperature can affect the alignment of polymer phases and, ultimately, scaffold pore anisotropy. Analytical results supported by preliminary biological studies demonstrate the higher ability of PCL/dioxane solution to promote the formation of aligned pores which provide a morphological guidance to cell advance during the preliminary stage of culture. These findings, taken as a whole, put the basis for a better informed regeneration of structurally complex tissues based on the modeling of scaffold micro and macro-architecture by thermodynamic forces.
The Health Care Costs of Violence Against Women
Authors: Kruse Marie , Sørensen Jan , Brønnum-Hansen Henrik , Helweg-Larsen Karin
Published: April 2011

The aim of this study is to analyze the health care costs of violence against women. For the study, we used a register-based approach where we identified victims of violence and assessed their actual health care costs at individual level in a bottom-up analysis. Furthermore, we identified a reference population. We computed the attributable costs, that is, the excess health care costs for victims compared to an identified reference population of nonvictims. Only costs within the health care sector were included, that is, somatic and psychiatric hospital costs, costs within the primary health care sector and costs of prescription pharmaceuticals. We estimated the attributable health care costs of violence against women in Denmark, using a generalized linear model where health care costs were modeled as a function of age, childbirth, and exposure to violence. In addition we tested whether socioeconomic status, multiple episodes of violence, and psychiatric contacts had any impact on health care costs. We found that the health care costs were about €1,800 higher for victims of violence than for nonvictims per year, driven mostly by higher psychiatric costs and multiple episodes of violence.
Review: Immune Markers in Breast Milk and Fetal and Maternal Body Fluids: A Systematic Review of Perinatal Concentrations
Authors: Agarwal Saroochi , Karmaus Wilfried , Davis Susan , Gangur Venu
Published: April 2011

Breastfeeding represents the continued exposure of the infant to the maternal immune environment. Uterine, perinatal, and postnatal exposure to immune factors may contribute to an infant’s risk of developing immune-mediated disorders, including allergies. A PubMed search was conducted to review studies in humans and analyze concentrations of immune markers (TGF-β, IFN-γ, eotaxin, CCL5, CXCL10, TNF-α, MCP-1, IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, sCD14, sIgA, IgG4, IgM) found in maternal serum, amniotic fluid, cord serum, colostrum, transition and mature milk. Concentrations of immune markers showed large variations across samples and studies. Reports documented conflicting results. Small sample sizes, differences in population characteristics, inconsistent sample collection times, and various sample collection and measurement methods may have led to wide variations in the concentrations of immune markers. Studies analyzing the associations between immune markers in maternal fluids and infant allergies remain inconclusive because of gaps in knowledge and a lack of standardized methods.
Defining Lactation Acuity to Improve Patient Safety and Outcomes
Authors: Mannel Rebecca
Published: April 2011

While substantial evidence exists identifying risks factors associated with premature weaning from breastfeeding, there are no previously published definitions of patient acuity in the lactation field. This article defines evidence-based levels of lactation acuity based on maternal and infant characteristics. Patient acuity, matching severity of illness to intensity of care required, is an important determinant of patient safety and outcomes. It is often used as part of a patient classification system to determine staffing needs and acceptable workloads in health care settings. As acuity increases, more resources, including more skilled clinicians, are needed to provide optimal care. Developing an evidence-based definition of lactation acuity can help to standardize terminology, more effectively distribute health care staff resources, encourage research to verify the validity and reliability of lactation acuity, and potentially improve breastfeeding initiation and duration rates.
Racial Diversity and Public Policy in the States
Authors: Matsubayashi Tetsuya , Rocha Rene R.
Published: April 2011

How does racial diversity affect public policy outcomes in the states? The policy backlash hypothesis suggests that the presence of blacks increases antagonistic attitudes toward minorities among whites and thus produces racially conservative policies. The electoral constraint hypothesis argues that the presence of blacks increases the size of population that supports policy liberalism and thus results in more liberal policies. The authors reconcile these competing explanations by arguing that the hypothesized negative impact of minority group size on policy liberalism varies across states in accordance with socioeconomic and institutional conditions that strengthen or weaken the impacts of electoral constraint or backlash.
Reviving the Schoolmaster
Authors: Hanley John , Salamone Michael , Wright Matthew
Published: April 2011

Many recent studies of the judiciary and public opinion adopt a model that views court decisions as aggravating division within the public. The authors question the image of Court as polarizer, arguing that the persuading influence of the U.S. Supreme Court is broader than contemporary authors acknowledge. Using a potential outcomes framework, the authors analyze public attitudes in response to the decision in Roe v. Wade, the original test case in Franklin and Kosaki’s seminal article. The authors’ evidence suggests that members of diverse groups who were aware of the Roe decision were more supportive of abortion than their decision-unaware counterparts.
Social Risk-Management Strategies in Pastoral Systems: A Qualitative Comparative Analysis
Authors: Moritz Mark , Giblin Julia , Ciccone Miranda , Davis Andréa , Fuhrman Jesse , Kimiaie Masoumeh , Madzsar Stefanie , Olson Kyle , Senn Matthew
Published: April 2011

Pastoralists risk losing their livelihood overnight due to drought, disease, and other disasters. They employ different strategies to minimize these risks, including the following: Mobility, herd maximization, diversification, and social strategies. Social strategies are considered critical because they provide not only a safety net during disasters but also contribute to the resilience of pastoral societies by allowing pastoralists to rebuild herds after disasters. There is, however, much variation in social risk-management strategies (SRMS) across pastoral societies. To understand this variation, we conducted a comparative study of 20 pastoral societies from different socioeconomic, historical, and environmental settings. We used Qualitative Comparative Analysis (QCA) to examine which causal configurations explain the variation in SRMS. This analytical approach helped us to identify four clusters of pastoral groups, in which different causal configurations are associated with exchange networks, patron—client relations, and noninstitutional SRMS.
The Ontology of Epistemological Production: Cases in Ethnography and Psychotherapy
Authors: Borck Cathy R.
Published: April 2011

The author draws on experiences as a researcher in a qualitative study that employed both ethnographic and interview methodologies as well as experiences as a patient in psychotherapy to theorize the subjective productions immanent to becoming a subject of knowledge discourses, where becoming a researcher and becoming a patient are two exemplary cases. The object of the present analysis are these disciplinary discourses and the use of them for knowledge production, exposing how they govern the ways that technologies simultaneously call forth and emerge from power to produce the subject as the object of their analyses. Drawing from experiences in the field and in session, the author demonstrates how disciplines produce discourses that categorize lived experience for the production of knowledge. The article traverses between subject positions and subjective experiences, equally interpellated within knowledge discourses that claim to make sense of various social and psychic conditions.
Exploring Performativity and Resistance in Qualitative Research Interviews: A Play in Four Acts
Authors: Beaunae Cathrine , Wu Chiu-Hui , Koro-Ljungberg Mirka
Published: April 2011

This play describes how the authors become aware of the complexities of resistance and performativity in the qualitative interview process. It also illustrates how this awareness and subsequent acquisition of knowledge changed and informed the way they viewed qualitative research interviewing. More specifically, performativity is put into work in this play through various theorists and examples from two qualitative research studies. As Cathrine and Vivian work together to understand resistance during the interviewing situations, with the assistance of a faculty member, Mirka, they discover theories and concepts that help them to better articulate their thoughts and describe their experiences in complex research situations. The authors learn that both performativity and resistance can challenge the normative nature of interviewing by opening up more complex knowledge construction and new spaces for interpretation.
Negotiating the Legacy of Hearingness
Authors: Sutton-Spence Rachel , West Donna
Published: April 2011

Rachel and Donna are hearing, sign-language-using researchers who, since 1989/1999, respectively, have worked in the field of Deaf Studies. In 2008, they were both invited, separately, to present at a conference called “I am Deaf: Deaf Studies in the 21st Century” that caused them to reassess who they are and where they fit with Deaf Studies. Donna presented, and Rachel booked a foreign holiday.
Fréchet differentiation of the stretch and rotation tensors
Authors: Wheeler Lewis T. , Casey James
Published: April 2011

Explicit formulas are derived for the Fréchet differentials and Fréchet derivatives of the right and left stretch tensors and the rotation tensor, regarded as functions of the deformation gradient. Novel decompositions, due to Chen and Wheeler, are re-interpreted.