bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of F-actin organization in p38 MAP kinase-mediated apoptosis and necrosis in neonatal rat cardiomyocytes subjected to simulated ischemia and reoxygenation
Authors: Okada Takayuki , Otani Hajime , Wu Yue , Kyoi Shiori , Enoki Chiharu , Fujiwara Hiroyoshi , Sumida Tomohiko , Hattori Reiji , Imamura Hiroji
Published: July 2005

Activation of p38 mitogen-activated protein (MAP) kinase (MAPK) has been implicated in the mechanism of cardiomyocyte (CMC) protection and injury. The p38 MAPK controversy may be related to differential effects of this kinase on apoptosis and necrosis. We have hypothesized that p38 MAPK-mediated F-actin reorganization promotes apoptotic cell death, whereas it protects from osmotic stress-induced necrotic cell death. Cultured neonatal rat CMCs were subjected to 2 h of simulated ischemia followed by reoxygenation. p38 MAPK activity measured by phosphorylation of MAP kinase-activated protein (MAPKAP) kinase 2 was increased during simulated ischemia and reoxygenation. This was associated with translocation of heat shock protein 27 (HSP27) from the cytosolic to the cytoskeletal fraction and F-actin reorganization. Cytochrome c release from mitochondria, caspase-3 activation, and DNA fragmentation were increased during reoxygenation. Robust lactate dehydrogenase (LDH) release was observed under hyposmotic (140 mosM) reoxygenation. The p38 MAPK inhibitor SB-203580 abrogated activation of p38 MAPK, translocation of HSP27, and F-actin reorganization and prevented cytochrome c release, caspase-3 activation, and DNA fragmentation. Conversely, SB-203580 enhanced LDH release during hyposmotic reoxygenation. The F-actin disrupting agent cytochalasin D inhibited F-actin reorganization and prevented cytochrome c release, caspase-3 activation, and DNA fragmentation, whereas it enhanced LDH release during hyposmotic reoxygenation. When CMCs were incubated under the isosmotic condition for the first 15 min of reoxygenation, SB-203580 and cytochalasin D increased ATP content of CMCs and prevented LDH release after the conversion to the hyposmotic condition. These results suggest that F-actin reorganization mediated by activation of p38 MAPK plays a differential role in apoptosis and protection against osmotic stress-induced necrosis during reoxygenation in neonatal rat CMCs; however, the sarcolemmal fragility caused by p38 MAPK inhibition can be reversed during temporary blockade of physical stress during reoxygenation.
Acetylcholine and sodium nitroprusside cause long-term inhibition of EDCF-mediated contractions
Authors: Tang Eva H. C. , Feletou Michel , Huang Yu , Man Ricky Y. K. , Vanhoutte Paul M.
Published: July 2005

Preliminary studies suggested that previous exposure to acetylcholine (ACh) exerts a delayed inhibition of subsequent contractions mediated by endothelium-derived contracting factor (EDCF). To confirm this long-term inhibitory effect of ACh and to determine whether nitric oxide (NO) mediates the phenomenon, we suspended rings of spontaneously hypertensive rat (SHR) aortas in organ chambers for the recording of isometric force. The rings were incubated in the absence or presence of Nω-nitro-l-arginine methyl ester (l-NAME; inhibitor of NO synthases) or 1 H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ; inhibitor of soluble guanylyl cyclase) before exposure to increasing concentrations of ACh or sodium nitroprusside (SNP) during contractions to phenylephrine. Thereafter, EDCF-mediated contractions to ACh or the calcium ionophore A-23187 were elicited. If the rings were preexposed to ACh or SNP, the subsequent ACh-induced EDCF-mediated contractions were reduced compared with those obtained in rings of the same arteries not previously exposed to either agent. ODQ did not affect the inhibition caused by preexposure to ACh but significantly reduced that caused by preexposure to SNP. Previous exposure to SNP reduced, whereas previous exposure to ACh did not affect, endothelium-dependent contractions to A-23187. Previous exposure to either ACh or SNP did not affect the contractions to the thromboxane mimetic U-46619. Thus ACh and SNP exert delayed inhibition of EDCF-mediated contractions via distinct pathways. The effect of ACh is NO independent and upstream of the increase in calcium concentration that triggers the release of EDCF. The effect of SNP is downstream of the calcium rise and is mainly NO dependent.
Acetylcholine-induced phosphorylation and membrane translocation of CPI-17 in bronchial smooth muscle of rats
Authors: Sakai Hiroyasu , Hirano Tomona , Chiba Yoshihiko , Misawa Miwa
Published: July 2005

A translocation of protein kinase C (PKC) from cytosol to plasma membrane has been reported as an association with agonist-induced Ca2+ sensitization in smooth muscle contraction. Therefore, it is possible that a downstream target of PKC, CPI-17 [PKC-potentiated inhibitory protein for heterotrimeric myosin light chain (MLC) phosphatase of 17 kDa], might also be translocated to membrane when activated. To confirm this hypothesis, cytosolic and membrane CPI-17 was measured in acetylcholine (ACh)- and high-K+ depolarization-stimulated bronchial smooth muscle of rats. An active form of CPI-17, i.e., Thr38-phosphorylated CPI-17, was also measured in cytosolic and membrane fractions. Immunoblot analyses demonstrated a translocation of CPI-17 from cytosolic to membrane fraction by ACh, but not high-K+ depolarization, stimulation in time- and concentration-dependent manners. Interestingly, phosphorylated CPI-17 was detected only in membrane fractions in the ACh-stimulated tissues. However, in the high-K+ depolarization-stimulated tissues, phosphorylated CPI-17 was not detected both in membrane and cytosolic fraction. To estimate downstream of activated CPI-17, immunoblotting for phosphorylated MLC was performed in ACh- or high-K+ depolarization-stimulated tissues. ACh- and high-K+ depolarization-induced phosphorylation of MLC was observed in its contraction-dependent manner. In conclusion, we, for the first time, suggested that CPI-17 is translocated and phosphorylated by ACh, but not high-K+ depolarization, in rat bronchial smooth muscle. ACh-induced translocation and phosphorylation of CPI-17 might be caused via the activation of muscarinic receptor.
Effects of rottlerin on silica-exacerbated systemic autoimmune disease in New Zealand mixed mice
Authors: Brown Jared M. , Schwanke Corbin M. , Pershouse Mark A. , Pfau Jean C. , Holian Andrij
Published: July 2005

Environmental crystalline silica exposure has been associated with formation of autoantibodies and development of systemic autoimmune disease, but the mechanisms leading to these events are unknown. Silica exposure in autoimmune-prone New Zealand mixed (NZM) mice results in a significant exacerbation of systemic autoimmunity as measured by increases in autoantibodies and glomerulonephritis. Previous studies have suggested that silica-induced apoptosis of alveolar macrophages (AM) contributes to the generation of the autoantibodies and disease. Rottlerin has been reported to inhibit apoptosis in many cell types, possibly through direct or indirect effects on PKCδ. In this study, rottlerin reduced silica-induced apoptosis in bone marrow-derived macrophages as measured by DNA fragmentation. In NZM mice, RNA and protein levels of PKCδ were significantly elevated in AM 14 wk after silica exposure. Therefore, rottlerin was used to reduce apoptosis of AM and evaluate the progress of silica-exacerbated systemic autoimmune disease. Fourteen weeks after silica exposure, NZM mice had increased levels of anti-histone autoantibodies, high proteinuria, and glomerulonephritis. However, silica-instilled mice that also received weekly instillations of rottlerin had significantly lower levels of proteinuria, anti-histone autoantibodies, complement C3, and IgG deposition within the kidney. Weekly instillations of rottlerin in silica-instilled NZM mice also inhibited the upregulation of PKCδ in AM. Together, these data demonstrate that in vivo treatment with rottlerin significantly decreased the exacerbation of autoimmunity by silica exposure.
Sensitization of pulmonary chemosensitive neurons by bombesin-like peptides in rats
Authors: Gu Qihai , Lee Lu-Yuan
Published: July 2005

Small cell lung cancer (SCLC) patients suffer from pulmonary stresses such as dyspnea and chest pain, and the pathogenic mechanisms are not known. SCLC cells secrete a variety of bioactive neuropeptides, including bombesin-like peptides. We hypothesize that these peptides may enhance the sensitivity of the pulmonary chemosensitive nerve endings, contributing to the development of these pulmonary stresses in SCLC patients. This study was therefore carried out to determine the effects of bombesin and gastrin-releasing peptide (GRP), a major bombesin-like peptide, on the sensitivities of pulmonary chemoreflex and isolated pulmonary vagal chemosensitive neurons. In anesthetized, spontaneously breathing rats, intravenous infusion of bombesin or GRP significantly amplified the pulmonary chemoreflex responses to chemical stimulants such as capsaicin and ATP. The enhanced responses were completely abolished by perineural capsaicin treatment of both cervical vagi, suggesting the involvement of pulmonary C-fiber afferents. In isolated pulmonary vagal chemosensitive neurons, pretreatment with bombesin or GRP potentiated the capsaicin-induced Ca2+ transient. This sensitizing effect was further demonstrated in patch-clamp recording studies; the sensitivities of these neurons to both chemical (capsaicin and ATP) and electrical stimuli were significantly enhanced by the presence of either bombesin or GRP. In summary, our results have demonstrated that bombesin and GRP upregulate the pulmonary chemoreflex sensitivity in vivo and the excitability of isolated pulmonary chemosensitive neurons in vitro.
Regulation of reactive oxygen species-induced endothelial cell-cell and cell-matrix contacts by focal adhesion kinase and adherens junction proteins
Authors: Usatyuk Peter V. , Natarajan Viswanathan
Published: July 2005

Oxidants, generated by activated neutrophils, have been implicated in the pathophysiology of vascular disorders and lung injury; however, mechanisms of oxidant-mediated endothelial barrier dysfunction are unclear. Here, we have investigated the role of focal adhesion kinase (FAK) in regulating hydrogen peroxide (H2O2)-mediated tyrosine phosphorylation of intercellular adhesion proteins and barrier function in endothelium. Treatment of bovine pulmonary artery endothelial cells (BPAECs) with H2O2increased tyrosine phosphorylation of FAK, paxillin, β-catenin, and vascular endothelial (VE)-cadherin and decreased transendothelial electrical resistance (TER), an index of cell-cell adhesion and/or cell-matrix adhesion. To study the role of FAK in H2O2-induced TER changes, BPAECs were transfected with vector or FAK wild-type or FAK-related non-kinase (FRNK) plasmids. Overexpression of FRNK reduced FAK expression and attenuated H2O2-mediated tyrosine phosphorylation of FAK, paxillin, β-catenin, and VE-cadherin and cell-cell adhesion. Additionally, FRNK prevented H2O2-induced distribution of FAK, paxillin, β-catenin, or VE-cadherin toward focal adhesions and cell-cell adhesions but not actin stress fiber formation. These results suggest that activation of FAK by H2O2is an important event in oxidant-mediated VE barrier function regulated by cell-cell and cell-matrix contacts.
Regulation of constitutive neutrophil apoptosis by the α,β-unsaturated aldehydes acrolein and 4-hydroxynonenal
Authors: Finkelstein Erik I. , Ruben Jurjen , Koot C. Wendy , Hristova Milena , van der Vliet Albert
Published: July 2005

Reactive α,β-unsaturated aldehydes are major components of common environmental pollutants and are products of lipid oxidation. Although these aldehydes have been demonstrated to induce apoptotic cell death in various cell types, we recently observed that the α,β-unsaturated aldehyde acrolein (ACR) can inhibit constitutive apoptosis of polymorphonuclear neutrophils and thus potentially contribute to chronic inflammation. The present study was designed to investigate the biochemical mechanisms by which two representative α,β-unsaturated aldehydes, ACR and 4-hydroxynonenal (HNE), regulate neutrophil apoptosis. Whereas low concentrations of either aldehyde (<10 μM) mildly promoted apoptosis in neutrophils (reflected by increased phosphatidylserine exposure, caspase-3 activation, and mitochondrial cytochrome c release), higher concentrations prevented critical features of apoptosis (caspase-3 activation, phosphatidylserine exposure) and caused delayed neutrophil cell death with characteristics of necrosis/oncosis. Inhibition of caspase-3 activation by either aldehyde occurred despite increases in mitochondrial cytochrome c release and occurred in close association with depletion of cellular GSH and with cysteine modifications within caspase-3. However, procaspase-3 processing was also prevented, because of inhibited activation of caspases-9 and -8 under similar conditions, suggesting that ACR (and to a lesser extent HNE) can inhibit both intrinsic (mitochondria dependent) and extrinsic mechanisms of neutrophil apoptosis at initial stages. Collectively, our results indicate that α,β-unsaturated aldehydes can inhibit constitutive neutrophil apoptosis by common mechanisms, involving changes in cellular GSH status resulting in reduced activation of initiator caspases as well as inactivation of caspase-3 by modification of its critical cysteine residue.
A Modified Logarithmic Law for Neutrally Stratified Flow over Low-Sloped Hills
Authors: Pellegrini Cláudio C. , Bodstein Gustavo C. R.
Published: July 2005

The study of the atmospheric boundary layer flow over two-dimensional low-sloped hills under a neutral atmosphere finds numerous applications in meteorology and engineering, such as the development of large-scale atmospheric models, the siting of wind turbines, and the estimation of wind loads on transmission towers and antennas. In this paper, the intermediate variable technique is applied to the momentum equations in streamline coordinates to divide the flow into regions, with each characterized by the dominance of different terms. Using a simple mixing-length turbulence closure, a simplified form of the x momentum equation is solved for the fully turbulent region, resulting in a modified logarithmic law. The solution is expressed as a power series correction to the classical logarithmic law that is valid for flat terrain. A new parameter appears: the effective radius of curvature of the hill. The modified logarithmic law is used to obtain new equations for the speedup, the relative speedup, the maximum speedup, and the height at which it occurs. A new speedup ratio is proposed to calculate the relative speedup at specific heights. The results are in very good agreement with the Askervein and Black Mountain field data.
Comparison of Model-Predicted Transport and Diffusion of Seeding Material with NOAA Satellite-Observed Seeding Track in Supercooled Layer Clouds
Authors: Yu Xing , Dai Jin , Rosenfeld Daniel , Lei Hengchi , Xu Xiaohong , Fan Peng , Chen Zhengqi
Published: July 2005

From 0615 to 0749 UTC 14 March 2000, an operation of cloud seeding for precipitation enhancement by aircraft was carried out in the middle part of Shaanxi Province, China. National Oceanic and Atmospheric Administration (NOAA)-14 satellite imagery was received at 0735 UTC for the study region. A vivid cloud track appeared on the satellite imagery; its length was about 350 km, and its average width and width maximum were 9 and 14 km, respectively. Through application of a three-dimensional numerical model of the transport and diffusion of the seeding material, the simulated plume shape, the turning points, and the width and length of seeding lines agree with that of the cloud pattern indicated by the satellite imagery. The track is consistent with the transport and diffusion of the seeding line. All of these factors suggest that the cloud track that is detected by satellite imaging is the direct physical evidence of cloud seeding near the cloud top, with the cloud responding to the transport and diffusion of the seeding material and/or the propagation of the glaciation by secondary effects. The track is indeed caused by the cloud seeding, and the model can predict the evolution of the response zone of cloud seeding. For this seeding case, the duration for segments of the seeding line varies between 20 and 80 min, and the time period for each segment of the seeding line diffusing to the maximum width is about from 40 to 70 min. One hour after cloud seeding, the dispersion rate of the cloud track is 7.0 km h−1, and the predicted expansion rates of the seeding material concentrations of 1 and 4 L−1 are 7.6 and 4.6 km h−1, respectively. The comparison demonstrates that the numerical model of transport and diffusion can predict the main characteristics of transport and diffusion of the seeding effect, and the simulation results are reasonable.
Satellite-Retrieved Microstructure of AgI Seeding Tracks in Supercooled Layer Clouds
Authors: Rosenfeld Daniel , Yu Xing , Dai Jin
Published: July 2005

NOAA Advanced Very High Resolution Radiometer (AVHRR) images revealed conspicuous tracks of glaciated cloud in thick supercooled layer clouds over central China. These tracks were identified as being artificially produced by cloud-seeding operations at the −10°C isotherm, less than 1 km below cloud tops, aimed at precipitation enhancement, by means of AgI acetone generators. The cloud composition was deduced by retrieving the cloud-top effective radius (re) and analyzing its spatial relations with cloud-top temperatures and with the visible reflectance. Cloud-top temperature varied between −13° and −17°C. The glaciation became apparent at cloud tops about 22 min after seeding. The glaciated tops sank and formed a channel in the supercooled layer cloud. The rate of sinking of about 40 cm s−1 is compatible with the fall velocity of ice crystals that are likely to form at these conditions. A thin line of new water clouds formed in the middle of the channel of the seeded track between 38 and 63 min after seeding, probably as a result of rising motions induced by the released latent heat of freezing. These clouds disappeared in the more mature segments of the seeded track, which continued to expand throughout the observation period of more than 80 min. Eventually the seeding tracks started to dissipate by expansion of the ambient cloud tops inward from the sides. Using the brightness temperature difference between 10.8 and 12.0 μm allowed for observation of the seeding signature deep in the clouds, even when it was obscured under thin supercooled layer clouds. This is the third and most detailed report of effects of advertent cloud seeding for precipitation enhancement being detected and analyzed based on satellite observations. It opens new possibilities of using satellites for directing and monitoring weather modification experiments and operations.
Daytime Global Cloud Typing from AVHRR and VIIRS: Algorithm Description, Validation, and Comparisons
Authors: Pavolonis Michael J. , Heidinger Andrew K. , Uttal Taneil
Published: July 2005

Three multispectral algorithms for determining the cloud type of previously identified cloudy pixels during the daytime, using satellite imager data, are presented. Two algorithms were developed for use with 0.65-, 1.6-/3.75-, 10.8-, and 12.0-μm data from the Advanced Very High Resolution Radiometer (AVHRR) on board the National Oceanic and Atmospheric Administration (NOAA) operational polar-orbiting satellites. The AVHRR algorithms are identical except for the near-infrared data that are used. One algorithm uses AVHRR channel 3a (1.6 μm) reflectances, and the other uses AVHRR channel 3b (3.75 μm) reflectance estimates. Both of these algorithms are necessary because the AVHRRs on NOAA-15 through NOAA-17 have the capability to transmit either channel 3a or 3b data during the day, whereas all of the other AVHRRs on NOAA-7 through NOAA-14 can only transmit channel 3b data. The two AVHRR cloud-typing schemes are used operationally in NOAA’s extended Clouds from AVHRR (CLAVR)-x processing system. The third algorithm utilizes additional spectral bands in the 1.38- and 8.5-μm regions of the spectrum that are available on the Moderate Resolution Imaging Spectroradiometer (MODIS) and will be available on the Visible–Infrared Imaging Radiometer Suite (VIIRS). The VIIRS will eventually replace the AVHRR on board the National Polar-Orbiting Operational Environmental Satellite System (NPOESS), which is currently scheduled to be launched in 2009. Five cloud-type categories are employed: warm liquid water, supercooled water–mixed phase, opaque ice, nonopaque high ice (cirrus), and cloud overlap (multiple cloud layers). Each algorithm was qualitatively evaluated through scene analysis and then validated against inferences of cloud type that were derived from ground-based observations of clouds at the three primary Atmospheric Radiation Measurement (ARM) Program sites to help to assess the potential continuity of a combined AVHRR channel 3a–AVHRR channel 3b–VIIRS cloud-type climatology. In this paper, “validation” is strictly defined as comparisons with ground-based estimates that are completely independent of the satellite retrievals. It was determined that the two AVHRR algorithms produce nearly identical results except for certain thin clouds and cloud edges. The AVHRR 3a algorithm tends to incorrectly classify the thin edges of some low- and midlevel clouds as cirrus and opaque ice more often than the AVHRR 3b algorithm. The additional techniques implemented in the VIIRS algorithm result in a significant improvement in the identification of cirrus clouds, cloud overlap, and overall phase identification of thin clouds, as compared with the capabilities of the AVHRR algorithms presented in this paper.
Using a Parameterization of a Radiative Transfer Model to Build High-Resolution Maps of Typical Clear-Sky UV Index in Catalonia, Spain
Authors: Badosa Jordi , González Josep-Abel , Calbó Josep , van Weele Michiel , McKenzie Richard L.
Published: July 2005

To perform a climatic analysis of the annual UV index (UVI) variations in Catalonia, Spain (northeast of the Iberian Peninsula), a new simple parameterization scheme is presented based on a multilayer radiative transfer model. The parameterization performs fast UVI calculations for a wide range of cloudless and snow-free situations and can be applied anywhere. The following parameters are considered: solar zenith angle, total ozone column, altitude, aerosol optical depth, and single-scattering albedo. A sensitivity analysis is presented to justify this choice with special attention to aerosol information. Comparisons with the base model show good agreement, most of all for the most common cases, giving an absolute error within ±0.2 in the UVI for a wide range of cases considered. Two tests are done to show the performance of the parameterization against UVI measurements. One uses data from a high-quality spectroradiometer from Lauder, New Zealand [45.04°S, 169.684°E, 370 m above mean sea level (MSL)], where there is a low presence of aerosols. The other uses data from a Robertson–Berger-type meter from Girona, Spain (41.97°N, 2.82°E, 100 m MSL), where there is more aerosol load and where it has been possible to study the effect of aerosol information on the model versus measurement comparison. The parameterization is applied to a climatic analysis of the annual UVI variation in Catalonia, showing the contributions of solar zenith angle, ozone, and aerosols. High-resolution seasonal maps of typical UV index values in Catalonia are presented.
Modeling of Aerosol Dispersion from a Busy Road in the Presence of Nanoparticle Fragmentation
Authors: Gramotnev Dmitri K. , Gramotnev Galina
Published: July 2005

A simple semianalytical model of dispersion of nanoparticle aerosols from a busy road in the presence of intensive particle fragmentation is developed. In particular, it is predicted that the total number concentration may be characterized by a significant maximum at an optimal distance from the road. Simple analytical existence conditions of such a maximum are derived. Applicability conditions for the model and the effect of turbulent diffusion and dry deposition of nanoparticles on the theoretical predictions are also discussed. As a result of the comparison of the theoretical predictions with the experimental results on the total number concentration as a function of distance from the road, the typical fragmentation rate coefficient has been determined as ≈0.086 s−1, with an estimated error of ∼30%.
Fast Computation of Microwave Radiances for Data Assimilation Using the “Successive Order of Scattering” Method
Authors: Greenwald Thomas , Bennartz Ralf , O’Dell Christopher , Heidinger Andrew
Published: July 2005

Fast and accurate radiative transfer (RT) models are crucial in making use of microwave satellite data feasible under all weather conditions in numerical weather prediction (NWP) data assimilation. A multistream “successive order of scattering” (SOS) RT model has been developed to determine its suitability in NWP for computing microwave radiances in precipitating clouds. Results show that the two-stream SOS model is up to 10 times as fast as and is as accurate as the commonly used delta-Eddington model for weaker scattering [column scattering optical depth (CSOD) < 0.01], but it is less accurate and is slower for higher frequencies (>30 GHz) in cases of moderately strong to strong scattering (CSOD > 5). If two- and four-stream SOS models are used in combination, however, it was found that 85.5-GHz brightness temperatures computed for 1° × 1° global forecast fields were more accurate (<0.5 K vs 1.5 K for CSOD > 0.1) and were executed 4 times as fast as the delta-Eddington model. The SOS method has been demonstrated as an alternative to other fast RT models for providing accurate and very rapid multiple-scattering calculations at thermal wavelengths for remote sensing studies and demanding applications such as operational NWP data assimilation.
An Empirical Investigation of Convective Planetary Boundary Layer Evolution and Its Relationship with the Land Surface
Authors: Santanello Joseph A. , Friedl Mark A. , Kustas William P.
Published: July 2005

Relationships among convective planetary boundary layer (PBL) evolution and land surface properties are explored using data from the Atmospheric Radiation Measurement Program Cloud and Radiation Test Bed in the southern Great Plains. Previous attempts to infer surface fluxes from observations of the PBL have been constrained by difficulties in accurately estimating and parameterizing the conservation equation and have been limited to multiday averages or small samples of daily case studies. Using radiosonde and surface flux data for June, July, and August of 1997, 1999, and 2001, a conservation approach was applied to 132 sets of daily observations. Results highlight the limitations of using this method on daily time scales caused by the diurnal variability and complexity of entrainment. A statistical investigation of the relationship among PBL and both land surface and near-surface properties that are not explicitly included in conservation methods indicates that atmospheric stability in the layer of PBL growth is the most influential variable controlling PBL development. Significant relationships between PBL height and soil moisture, 2-m potential temperature, and 2-m specific humidity are also identified through this analysis, and it is found that 76% of the variance in PBL height can be explained by observations of stability and soil water content. Using this approach, it is also possible to use limited observations of the PBL to estimate soil moisture on daily time scales without the need for detailed land surface parameterizations. In the future, the general framework that is presented may provide a means for robust estimation of near-surface soil moisture and land surface energy balance over regional scales.
Storm Precipitation in the United States. Part II: Soil Erosion Characteristics
Authors: Angel James R. , Palecki Michael A. , Hollinger Steven E.
Published: July 2005

Soil erosion is a major global challenge. An increased understanding of the mechanisms driving soil erosion, especially the storms that produce it, is vital to reducing the impact on agriculture and the environment. The objective of this work was to study the spatial distribution and time trends of the soil erosion characteristics of storms, including the maximum 30-min precipitation intensity (I30), storm kinetic energy of the falling precipitation (KE), and the storm erosivity index (EI) using a long-term 15-min precipitation database. This is the first time that such an extensive climatology of soil erosion characteristics of storms has been produced. The highest mean I30, KE, and EI values occurred in all seasons in the southeastern United States, while the lowest occurred predominantly in the interior west. The lowest mean I30, KE, and EI values typically occurred in winter, and the highest occurred in summer. The exception to this was along the West Coast where winter storms exhibited the largest mean KE and EI values. Linear regression was used to identify trends in mean storm erosion characteristics for nine U.S. zones over the 31-yr study period. The south-central United States showed increases for all three storm characteristics for all four seasons. On the other hand, higher elevations along the West Coast showed strong decreases in all three storm characteristics across all seasons. The primary agricultural region in the central United States showed significant increases in fall and winter mean EI when there is less vegetative cover. These results underscore the need to update the storm climatology that is related to soil erosion on a regular basis to reflect changes over time.
Storm Precipitation in the United States. Part I: Meteorological Characteristics
Authors: Palecki Michael A. , Angel James R. , Hollinger Steven E.
Published: July 2005

Climate studies of precipitation have generally focused on daily or longer time scales of precipitation accumulation. The main objective of this work was to identify the precipitation characteristics of storms based on 15-min precipitation data, including storm total precipitation, storm duration, mean storm intensity, and maximum 15-min intensity. A group of precipitation characteristics was subjected to a cluster analysis that identified nine regions of the conterminous United States with homogeneous seasonal cycles of mean storm precipitation characteristics. Both mean and extreme statistics were derived for each characteristic and season for each zone. Continuous probability density functions were generated that appropriately fit the empirical distributions of storm total precipitation and maximum 15-min intensity. The storm characteristics, in turn, were a function of seasonal water availability from source regions, atmospheric water vapor capacity, and storm precipitation mechanism. This is the first time that such an extensive climatology of storm precipitation characteristics has been produced. A preliminary trend analysis of the 1972–2002 storm characteristic data by zone showed substantial changes that tended to be geographically coherent, with noteworthy differences between the western and eastern United States. The western United States displayed a trend toward decreasing storm total precipitation and storm duration in most seasons, while storm intensity increased. The eastern United States experienced a general pattern of increasing storm total precipitation and storm duration during winter, as well as a tendency for maximum 15-min precipitation intensity to increase.
Assessment of the Performance of the Chilbolton 3-GHz Advanced Meteorological Radar for Cloud-Top-Height Retrieval
Authors: Naud C. M. , Muller J-P. , Slack E. C. , Wrench C. L. , Clothiaux E. E.
Published: July 2005

The Chilbolton 3-GHz Advanced Meteorological Radar (CAMRa), which is mounted on a fully steerable 25-m dish, can provide three-dimensional information on the presence of hydrometeors. The potential for this radar to make useful measurements of low-altitude liquid water cloud structure is investigated. To assess the cloud-height assignment capabilities of the 3-GHz radar, low-level cloud-top heights were retrieved from CAMRa measurements made between May and July 2003 and were compared with cloud-top heights retrieved from a vertically pointing 94-GHz radar that operates alongside CAMRa. The average difference between the 94- and 3-GHz radar-derived cloud-top heights is shown to be −0.1 ± 0.4 km. To assess the capability of 3-GHz radar scans to be used for satellite-derived cloud-top-height validation, multiangle imaging spectroradiometer (MISR) cloud-top heights were compared with both 94- and 3-GHz radar retrievals. The average difference between 94-GHz radar and MISR cloud-top heights is shown to be 0.1 ± 0.3 km, while the 3-GHz radar and MISR average cloud-top-height difference is shown to be −0.2 ± 0.6 km. In assessing the value of the CAMRa measurements, the problems associated with low-reflectivity values from stratiform liquid water clouds, ground clutter, and Bragg scattering resulting from turbulent mixing are all addressed. It is shown that, despite the difficulties, the potential exists for CAMRa measurements to contribute significantly to liquid water cloud-top-height retrievals, leading to the production of two-dimensional transects (i.e., maps) of cloud-top height.
Assimilation of Doppler Radar Observations with a Regional 3DVAR System: Impact of Doppler Velocities on Forecasts of a Heavy Rainfall Case
Authors: Xiao Qingnong , Kuo Ying-Hwa , Sun Juanzhen , Lee Wen-Chau , Lim Eunha , Guo Yong-Run , Barker Dale M.
Published: July 2005

In this paper, the impact of Doppler radar radial velocity on the prediction of a heavy rainfall event is examined. The three-dimensional variational data assimilation (3DVAR) system for use with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) is further developed to enable the assimilation of radial velocity observations. Doppler velocities from the Korean Jindo radar are assimilated into MM5 using the 3DVAR system for a heavy rainfall case that occurred on 10 June 2002. The results show that the assimilation of Doppler velocities has a positive impact on the short-range prediction of heavy rainfall. The dynamic balance between atmospheric wind and thermodynamic fields, based on the Richardson equation, is introduced to the 3DVAR system. Vertical velocity (w) increments are included in the 3DVAR system to enable the assimilation of the vertical velocity component of the Doppler radial velocity observation. The forecast of the hydrometeor variables of cloud water (qc) and rainwater (qr) is used in the 3DVAR background fields. The observation operator for Doppler radial velocity is developed and implemented within the 3DVAR system. A series of experiments, assimilating the Korean Jindo radar data for the 10 June 2002 heavy rainfall case, indicates that the scheme for Doppler velocity assimilation is stable and robust in a cycling mode making use of high-frequency radar data. The 3DVAR with assimilation of Doppler radial velocities is shown to improve the prediction of the rainband movement and intensity change. As a result, an improved skill for the short-range heavy rainfall forecast is obtained. The forecasts of other quantities, for example, winds, are also improved. Continuous assimilation with 3-h update cycles is important in producing an improved heavy rainfall forecast. Assimilation of Doppler radar radial velocities using the 3DVAR background fields from a cycling procedure produces skillful rainfall forecasts when verified against observations.
Ice Cloud Retrievals and Analysis with the Compact Scanning Submillimeter Imaging Radiometer and the Cloud Radar System during CRYSTAL FACE
Authors: Evans K. Franklin , Wang James R. , Racette Paul E. , Heymsfield Gerald , Li Lihua
Published: July 2005

Submillimeter-wave radiometry is a new technique for determining ice water path (IWP) and particle size in upper-tropospheric ice clouds. The first brightness temperatures images of ice clouds above 340 GHz were measured by the Compact Scanning Submillimeter Imaging Radiometer (CoSSIR) during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL) Florida Area Cirrus Experiment (FACE) campaign in July 2002. CoSSIR operated with 12 channels from receivers at 183, 220, 380, 487, and 640 GHz. CoSSIR and the nadir-viewing 94-GHz Cloud Radar System (CRS) flew on the NASA ER-2 airplane based out of Key West, Florida. A qualitative comparison of the CoSSIR brightness temperatures demonstrates that the submillimeter-wave frequencies are more sensitive to anvil ice cloud particles than are the lower frequencies. A Bayesian algorithm, with a priori microphysical information from in situ cloud probes, is used to retrieve the IWP and median mass equivalent sphere particle diameter (Dme). Microwave scattering properties of random aggregates of plates and aggregates of frozen droplets are computed with the discrete dipole approximation (DDA) and an effective medium approximation tuned to DDA results. As a test of the retrievals, the vertically integrated 94-GHz radar backscattering is also retrieved from the CoSSIR data and compared with that measured by the CRS. The integrated backscattering typically agrees within 1–2 dB for IWP from 1000 to 10 000 g m−2, and while the disagreement increases for smaller IWP, it is typically within the Bayesian error bars. Retrievals made with only the three 183- and one 220-GHz channel are generally as good or better than those including 380 ± 6.2 and 640 GHz, because the CoSSIR submillimeter-wave channels were much noisier than expected. An algorithm to retrieve profiles of ice water content and Dme from CRS and CoSSIR data was developed. This Bayesian algorithm also retrieves the coefficients of an IWC–radar reflectivity power-law relation and could be used to evaluate radar-only ice cloud retrieval algorithms.
Doppler Radar Observations of Mesoscale Wind Divergence in Regions of Tropical Convection
Authors: Mapes Brian E. , Lin Jialin
Published: July 2005

A simple new analysis method for large single-Doppler radar datasets is presented, using data from several tropical field experiments. A cylindrical grid is chosen, to respect both the geophysical importance of altitude and the radar importance of range and azimuth. Horizontal and temporal fine structure are sacrificed, by compiling data as hourly histograms in 12 × 24 × 36 spatial grid cells of 15° azimuth × 8 km horizontal range × 500 m height, respectively. Mean Doppler radial velocity in each region is automatically unfolded (dealiased) using a simple histogram method, and fed into a velocity–azimuth display (VAD) analysis. The result is a set of hourly horizontal wind and wind divergence profiles, with associated error estimates, for circles of different radii centered on the radar.

These divergence profiles contain useful heating profile information in many weather situations, not just occasional cases of uniform widespread rainfall. Consistency of independent estimates for concentric circles, continuity from hour to hour, and good mass balance indicate high-quality results in one 48-h example sequence shown, from the East Pacific Investigations of Climate (EPIC 2001) experiment. Linear regression of divergence profiles versus reflectivity-estimated surface rain rates is used to illustrate the dominant systematic pattern: convective rain with low-level wind convergence evolves into stratiform rain with middle-level convergence, on a characteristic time scale of several hours. Absolute estimates of moisture convergence per unit of Z–R calculated rainfall vary strongly among experiments, in ways that appear to indicate reflectivity calibration errors. This indicates that Doppler data may offer a useful and unique bulk constraint on rainfall estimation by radar.
The Influence of Incipient Latent Heat Release on the Precipitation Distribution of the 24–25 January 2000 U.S. East Coast Cyclone
Authors: Brennan Michael J. , Lackmann Gary M.
Published: July 2005

The role of a diabatically produced lower-tropospheric potential vorticity (PV) maximum in determining the precipitation distribution of the 24–25 January 2000 U.S. East Coast cyclone is investigated. Operational numerical weather prediction (NWP) models performed poorly with this storm, even within 24 h of the event, as they were unable to properly forecast the westward extent of heavy precipitation over the Carolinas and mid-Atlantic. The development of an area of incipient precipitation (IP) around 0600 UTC 24 January over the southeastern United States prior to rapid cyclogenesis was also poorly forecasted by the operational NWP models. It is hypothesized that the lower-tropospheric diabatic PV maximum initially produced by the IP was important to subsequent inland moisture transport over the Carolinas and mid-Atlantic. A PV budget confirms that latent heat release in the midtroposphere associated with the IP led to the initial formation of a PV maximum in the lower troposphere that propagated eastward in association with the IP to the Atlantic coast late on 24 January. The impact of this PV maximum on the westward moisture transport was quantified by piecewise Ertel PV inversion. Results from the inversion show that the balanced flow associated with this evolving cyclonic PV maximum contributed substantially to the onshore moisture flux into the Carolinas and Virginia. The balanced flow associated with the PV anomaly also contributed to quasigeostrophic forcing for ascent in the region. These findings suggest that accurate numerical prediction of the precipitation distribution in this event requires adequate representation of the IP and its associated impacts on the PV distribution.
Unintentional Voter Mobilization: Does Participation in Preelection Surveys Increase Voter Turnout?
Authors: Mann Christopher B.
Published: July 2005

Survey researchers have long been concerned with the question of whether participation in preelection surveys increases voter turnout. This article presents findings from three large-scale field experiments conducted during the 2002 general election in Maryland, New York, and Pennsylvania. Unlike early studies, which found that participation in preelection surveys increased voter turnout, this study finds no significant effect. The author argues that the rigorous experimental methodology and large sample size in these three experiments should allay concern that survey participation affects turnout.
Lady, Girl, Female, or Woman
Authors: Cralley Elizabeth L. , Ruscher Janet B.
Published: July 2005

Two studies investigated whether modern sexism predicts men’s use of gender-biased terms for women. When established norms suggest a preference for neutral terms (e.g., woman, female), men lower in sexism should avoid potentially biased terms (e.g., lady, girl). Adhering to such an established norm, however, may require conscious effort. In Study 1, men lower in modern sexism used fewer gender-biased terms in a written format than did men higher in modern sexism. Study 2 replicated this result using an oral format but only when men were not cognitively busy with another task. Cognitive busyness apparently interfered with low modern sexists’ efforts to use more neutral terms. Implications for other forms of gender-biased language, as well as for long-term change in the use of gender-biased language, are discussed.
Exploring the Determinants of Decisions to Privatize State Prisons
Authors: Price Byron E. , Riccucci Norma M.
Published: July 2005

This study examines the potential determinants of state governments to privatize their prisons. Based on prison privatization data across the 50 states, the study finds that political factors such as the political culture of a state and the party controlling the legislature are more likely to influence decisions to privatize than those typically offered by advocates of prison privatization—fiscal or economic concerns, such as cost savings. The interesting twist here, however, is that due to a host of factors such as prison overcrowding and the increased popular demand for privatization as a way to address overcrowding, even those states that have Democrat-controlled legislatures are pursuing prison privatization.
Brain Circulation: Unparalleled Opportunities, Underlying Challenges, and Outmoded Presumptions
Authors: Teferra Damtew
Published: July 2005

An emerging global phenomenon of significant proportions, the mobility of high-level personnel affects the socioeconomic and sociocultural progress of a nation and the world. The information era has conquered the barriers of distance and space, opening up a whole array of opportunities and challenges affecting the mode in which the world interacts and coexists. Instantaneous communication and its declining cost, massive capital movement across borders, the growing hegemony of multinational corporations, greater talent demand to maintain global competitiveness and replenish national pool, relative ease in the movement of people, shift in geopolitics, the emergence of the greener pasture paradigm, and the decline of many Third World countries to provide commensurate living standards have catalyzed the global mobility trend of highly trained personnel. This article explores potentials advanced by the mobility of high-level expertise while examining emerging challenges. It also scrutinizes outmoded assumptions embedded in the current understanding of the mobility process.
Parent-Training Programs in Child Welfare Services: Planning for a More Evidence-Based Approach to Serving Biological Parents
Authors: Barth Richard P. , Landsverk John , Chamberlain Patricia , Reid John B. , Rolls Jennifer A. , Hurlburt Michael S. , Farmer Elizabeth M. Z. , James Sigrid , McCabe Kristin M. , Kohl Patricia L.
Published: July 2005

Child welfare service agencies provide parent training as part of their legally mandated responsibility to provide services to assist families to keep their children at home or to achieve reunification. The use of parent-training programs for families in the child welfare system has undergone relatively little examination. Mental health, special education, and juvenile justice have been identifying evidence-based approaches that have demonstrated effectiveness with children and families with conduct disorders and other behavioral problems, although few of these interventions have been tested with child welfare services clientele. This article brings together evidence about the most promising programs from other child service sectors with information about the current parent training approaches in child welfare and generates a range of proposals about next steps to enhance the capacity of parent training and fulfill the high expectations set in law and practice.
Policing in Black and White: Ethnic Group Differences in Trust and Confidence in the Police
Authors: Tyler Tom R.
Published: July 2005

Public trust and confidence in the police is generally low, with minority group members especially mistrustful of the police. This study uses a sample of New Yorkers to examine, first, whether trust is related to public willingness to cooperate with the police. The results suggest that it is. Second, this study examines the relationship of police policies and practices to trust in the police. The study finds that trust is most strongly influenced by public judgments about the fairness of the procedures that the police follow when exercising their authority. These process-based judgments are more influential than are either assessments of the effectiveness of police crime-control activities or judgments about the fairness of the police distribution of services. These findings support the process-based model of regulation.