bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrarenal Dopaminergic System Regulates Renin Expression
Authors: Zhang Ming-Zhi , Yao Bing , Fang Xiaofeng , Wang Suwan , Smith James P. , Harris Raymond C.
Published: January 2009

Dopamine is a major regulator of proximal tubule salt reabsorption and is a modulator of renin release. Dopamine has been reported to stimulate renin release in vitro through activation of D1-like receptors. However, previous studies investigating dopamine regulation of renin release in vivo have provided contradictory results, indicating stimulation, inhibition, or no effect. We have reported previously that macula densa cyclooxygenase-2 (COX-2) is suppressed by dopamine. Because macula densa COX-2 stimulates renal renin expression, our current studies investigated dopamine regulation of renal renin release and synthesis in vivo. Acute treatment with a D1-like receptor agonist, fenoldopam, significantly inhibited renin release, as did acute inhibition of proximal tubule salt reabsorption with acetazolamide. In catechol-
O
-methyl transferase knockout (COMT
−/−
) mice, which have increased kidney dopamine levels because of deletion of the major intrarenal dopamine metabolizing enzyme, there was attenuation in response to a low-salt diet of the increases of renal cortical COX-2 and renin expression and renin release. A high-salt diet led to significant decreases in renal renin expression but much less significant decreases in COMT
−/−
mice than wild type mice, resulting in higher renal renin expression in COMT
−/−
mice. In high salt–treated wild-type mice or COX-2 knockout mice on a normal salt diet, fenoldopam stimulated renal renin expression. These results suggest that dopamine predominantly inhibits renal renin expression and release by inhibiting macula densa COX-2, but suppression of renal cortical COX-2 activity reveals a contrasting effect of dopamine to stimulate renal renin expression through activation of D1-like receptors.
The Heart of the Matter: The Security of Women and the Security of States
Authors: Hudson Valerie M. , Caprioli Mary , Ballif-Spanvill Bonnie , McDermott Rose , Emmett Chad F.
Published: January 2009

Does the security of women influence the security and behavior of states? Existing evidence linking the situation of women to state-level variables such as economic prosperity and growth, health, and corruption is fairly conclusive. Questions remain, however, concerning the degree to which state security and state security-related behavior is linked to the security of women. The “women and peace” thesis draws upon evolutionary biology/psychology for ultimate causes of this linkage, and sociological theories of social diffusion and psychological theories of social learning for more proximate causal mechanisms. Together, a new data resource—the WomanStats Database—and conventional methodology find a robust, positive relationship between the physical security of women and three measures of state security and peacefulness. In addition, a comparison of this proposition to alternative explanations involving level of democracy, level of economic development, and civilizational identity shows that the physical security of women is a better predictor of state security and peacefulness. Although these results are preliminary, it is still possible to conclude that the security of women must not be overlooked in the study of state security, especially given that the research questions to be raised and the policy initiatives to be considered in the promotion of security will differ markedly if the security of women is seriously considered as a significant influence on state security.
Spoiling Inside and Out: Internal Political Contestation and the Middle East Peace Process
Authors: Pearlman Wendy
Published: January 2009

Actors turn to negotiating or spoiling as a means of contesting not only what a proposed peace settlement entails but also who has the power to decide the terms. Conflicts are more likely to witness negotiating and spoiling for purposes of internal contestation to the degree that one or both of the warring parties lack an institutionalized system of legitimate representation. Whether internal contestation leads a group to act as a peace maker or as a peace breaker is conditioned by its position in the internal balance of power. Two eras in the Palestinian national movement—the Palestine Liberation Organization's bid to join the Geneva peace conference in 1973–74 and its engagement in the Oslo peace process from 1993 to 2000—illustrate these propositions. Leaders of national movements and rebel groups, no less than leaders of states, are systematically influenced by domestic politics. As such, sponsors of peace processes should expect spoiler problems unless a movement heals rifts within its ranks.
On the Combined Effects of Turbulence and Gravity on Droplet Collisions in Clouds: A Numerical Study
Authors: Woittiez Eric J. P. , Jonker Harm J. J. , Portela Luís M.
Published: January 2009

This paper examines the combined influences of turbulence and gravity on droplet collision statistics in turbulent clouds by means of direct numerical simulation (DNS). The essential microphysical mechanisms that determine the geometric collision kernel are explored by studying how gravity affects droplet relative velocities and preferential concentration of both monodisperse and bidisperse droplet distributions. To this end, collision statistics of large amounts of droplets with radii ranging from 10 to 90 μm, driven by a turbulent flow field and gravity, are calculated. The flow is homogeneous and isotropic and has a dissipation rate of ε = 4.25 × 10−2 m2 s−3. The results show that in the calculation of collision statistics, the interplay between gravity and turbulence is an essential element and not merely an addition of separate phenomena. For example, the presence of gravity leads to clustering of large droplets interacting with the larger scales of turbulence in the DNS. The collision statistics of a bidisperse droplet distribution, even with a very small radius difference, shows profoundly different behavior than the monodisperse case.
Reconstructing the Past Wind Stresses over the Tropical Pacific Ocean from 1875 to 1947
Authors: Deng Ziwang , Tang Youmin
Published: January 2009

An important step in understanding the climate system is simulating and studying the past climate variability, using oceanic models, atmospheric models, or both. Toward this goal, long-term wind stress data, as the forcing of oceanic or climate models, are often required. In this study, the possibility of reconstructing the past winds of the tropical Pacific Ocean using historical sea surface temperature (SST) and sea level pressure (SLP) datasets was explored. Four statistical models, based on principal component (PC) regression and singular vector decomposition (SVD), were developed for reconstructing monthly pseudo wind stress over the tropical Pacific for the period 1875–1947. The high-frequency noise was removed from the raw data prior to the reconstruction. These models are SST-based PC regression (model 1), SLP-based PC regression (model 2), SST-based SVD (model 3), and SLP-based SVD (model 4). The results show that reconstructed wind stresses from all models can account for more than one-half of the total variances. In general, the SLP is better than SST as a predictor and the SVD method is superior to the PC regression. Forced by these reconstructed wind stresses, an oceanic general circulation model can simulate realistic interannual variability of the tropical Pacific SST. However, the wind stress reconstructed by SST-based models leads to better simulation skill in comparison with that from SLP-based models. Last, a long-term wind stress dataset was constructed for the period from 1875 to 1947 by the SST-based SVD model, which provides a useful tool for studying the past climate variability over the tropical Pacific, especially for El Niño–Southern Oscillation.
Cloud Microphysics Impact on Hurricane Track as Revealed in Idealized Experiments
Authors: Fovell Robert G. , Corbosiero Kristen L. , Kuo Hung-Chi
Published: January 2009

Analyses of tropical cyclones created in an idealized environment reveal how and why cloud microphysical assumptions can influence storm motion, including speed and direction. It is well known that in the absence of a mean flow, a leading factor in storm propagation is the establishment of “beta gyres” owing to planetary vorticity advection by the storm’s circulation. Previous research demonstrated that tangential winds well beyond the core influence storm motion by helping to determine the gyres’ orientation and intensity.

Microphysical assumptions, especially involving average particle fall speeds, can strongly influence the winds at outer radius. More specifically, microphysics modulates the radial distribution of column-average virtual temperature, which largely determines the radial surface pressure gradient and therefore the winds because they tend to be in gradient balance beyond the core. Microphysics schemes can differ markedly with respect to average fall speed, depending on the complexity of the scheme and how interactions among condensation types are handled. Average fall speed controls the outward movement of particles produced in the eyewall into the anvil, where they can influence the environment through cloud–radiative interactions and phase changes.

With the assistance of some special sensitivity tests, the influence of microphysics and fall speed on radial temperature gradients, leading to different outer wind strengths and tracks, is shown. Among other things, this work demonstrates that the treatment of outer rainbands in operational models can potentially influence how simulated storms move, thus affecting position forecasts.
Baroclinic Instability in the Eady Model: Interpretations
Authors: Egger Joseph
Published: January 2009

The mechanism of baroclinic instability in the Eady model is interpreted by explicitly calculating the ageostrophic circulations related to the model’s hyperbolic basic functions. It is advantageous to perform the analysis at the midlevel where the model’s “barotropic” mode provides the streamfunction and the “baroclinic” mode represents the temperature. These modes interact and instability occurs if the horizontal advection of background potential temperature by the barotropic mode dominates over the vertical one because of the same mode at the midlevel. A rather simple picture of the stable as well as the unstable flow configurations emerges. Other interpretations are discussed briefly.
A Homogeneous Stochastic Model of the Madden–Julian Oscillation
Authors: Jones Charles
Published: January 2009

This paper presents a new empirical model to simulate the Madden–Julian oscillation (MJO), which is the most prominent mode of tropical intraseasonal variability. Zonal wind components at 850 and 200 hPa from reanalysis (1948–2007) and outgoing longwave radiation from satellites (1979–2007) are used to identify MJOs and characterize their statistical properties.

The temporal variability of the MJO is represented with a nine-state first-order Markov chain in which state 0 represents quiescent days and states 1–8 are phases of the MJO when it is active. Transition probabilities are estimated based on the historical record of MJO events, and sensitivity tests were performed to evaluate the best estimates for a homogeneous model. Once the model simulates time series of phase transitions, composites of convective and circulation anomalies determine the spatial structure of the events. The amplitudes of the MJOs are stochastically generated with an amplitude factor that has a Gaussian frequency distribution.

MJO events generated by the homogeneous stochastic model occur irregularly in time and can appear as single isolated events or sequences of successive MJOs. The MJO in the model can have different eastward propagations and the zonal scale is consistent with the observations. The simulated MJOs have different durations (30–90 days), and each event can be stronger or weaker than the mean composite according to a normal distribution. The results show that the homogeneous stochastic model simulates the irregularity of the MJO and model biases are small. Possible applications and future extensions of the homogeneous stochastic model are discussed.
On the Relationship between Synoptic Wintertime Atmospheric Variability and Path Shifts in the Gulf Stream and the Kuroshio Extension
Authors: Joyce Terrence M. , Kwon Young-Oh , Yu Lisan
Published: January 2009

Coherent, large-scale shifts in the paths of the Gulf Stream (GS) and the Kuroshio Extension (KE) occur on interannual to decadal time scales. Attention has usually been drawn to causes for these shifts in the overlying atmosphere, with some built-in delay of up to a few years resulting from propagation of wind-forced variability within the ocean. However, these shifts in the latitudes of separated western boundary currents can cause substantial changes in SST, which may influence the synoptic atmospheric variability with little or no time delay. Various measures of wintertime atmospheric variability in the synoptic band (2–8 days) are examined using a relatively new dataset for air–sea exchange [Objectively Analyzed Air–Sea Fluxes (OAFlux)] and subsurface temperature indices of the Gulf Stream and Kuroshio path that are insulated from direct air–sea exchange, and therefore are preferable to SST. Significant changes are found in the atmospheric variability following changes in the paths of these currents, sometimes in a local fashion such as meridional shifts in measures of local storm tracks, and sometimes in nonlocal, broad regions coincident with and downstream of the oceanic forcing. Differences between the North Pacific (KE) and North Atlantic (GS) may be partly related to the more zonal orientation of the KE and the stronger SST signals of the GS, but could also be due to differences in mean storm-track characteristics over the North Pacific and North Atlantic.
Analyzing the Concurrence of Meteorological Droughts and Warm Periods, with Implications for the Determination of Evaporative Regime
Authors: Koster R. D. , Schubert S. D. , Suarez M. J.
Published: January 2009

The hydroclimatic conditions under which a seasonal meteorological drought (below-normal seasonal rainfall) can induce an increase in seasonal air temperature are investigated, first with an atmospheric general circulation model (AGCM) and then with observations. Geographical differences in the dryness–warmth connection abound in the AGCM; in the United States, for example, identified evaporative controls tend to tie meteorological droughts to warmer temperatures in the South but not in the Northeast. The strong agreement between AGCM and observations-based geographical patterns of drought-induced warming supports the idea that the same evaporative controls are also present in nature. A powerful side benefit of the analysis of drought-induced warming is a Northern Hemisphere map, derived solely from observations, showing where total boreal summer evaporation is controlled by soil moisture, energy availability, or both.
PDFs of Tropical Tropospheric Humidity: Measurements and Theory
Authors: Ryoo Ju-Mee , Igusa Takeru , Waugh Darryn W.
Published: January 2009

The spatial variations in the probability density functions (PDFs) of relative humidity (RH) in the tropical and subtropical troposphere are examined using observations from the Atmospheric Infrared Sounder (AIRS) and the Microwave Limb Sounder (MLS) instruments together with a simple statistical model. The model, a generalization of that proposed by Sherwood et al., assumes the RH is determined by a combination of drying by uniform subsidence and random moistening events and has two parameters: r, the ratio of the drying time by subsidence to the time between moistening events, and k, a measure of the variability of the moistening events. The observations show that the characteristics of the PDFs vary between the tropics and subtropics, within the tropics or subtropics, and with altitude. The model fits the observed PDFs well, and the model parameters concisely characterize variations in the PDFs and provide information on the processes controlling the RH distributions. In tropical convective regions, the model PDFs that match the observations have large r and small k, indicating rapid random remoistening, which is consistent with direct remoistening in convection. In contrast, in the nonconvective regions there are small r and large k, indicating slower, less random remoistening, consistent with remoistening by slower, quasi-horizontal transport. The statistical model derived will be useful for quantifying differences between, or temporal changes in, RH distributions from different datasets or models, and for examining how changes in physical processes could alter the RH distribution.
Dynamics of Late Spring Rainfall Reduction in Recent Decades over Southeastern China
Authors: Qiu Yun , Cai Wenju , Guo Xiaogang , Pan Aijun
Published: January 2009

Since 1951, late spring (May) rainfall over southeastern China (SEC) has decreased by more than 30% from its long-term average, in contrast to a rainfall increase in boreal summer. The dynamics have yet to be fully determined. This paper shows that as the Indo-Pacific enters into a La Niña phase, significant negative mean sea level pressure (MSLP) anomalies grow over the Indian Ocean and the western Pacific sector. The associated large-scale southwesterly anomalies transport moisture to the nearby South China Sea and the SEC region, contributing to a higher rainfall. A presence of a Philippine Sea anticyclonic (PSAC) pattern, arising from a decaying El Niño, strengthens the rain-conducive flow to SEC, but it is not a necessary condition. During the past decades, an increase in protracted El Niño events accompanied by a reduction in La Niña episodes has contributed to the May rainfall decline. The extent to which climate change is contributing is discussed.
Seasonal-to-Interannual Variability of Ethiopia/Horn of Africa Monsoon. Part I: Associations of Wavelet-Filtered Large-Scale Atmospheric Circulation and Global Sea Surface Temperature
Authors: Segele Zewdu T. , Lamb Peter J. , Leslie Lance M.
Published: January 2009

Horn of Africa rainfall varies on multiple time scales, but the underlying climate system controls on this variability have not been examined comprehensively. This study therefore investigates the linkages between June–September Horn of Africa (especially Ethiopian) rainfall and regional atmospheric circulation and global sea surface temperature (SST) variations on several key time scales. Wavelet analysis of 5-day average or monthly total rainfall for 1970–99 identifies the dominant coherent modes of rainfall variability. Several regional atmospheric variables and global SST are then identically wavelet filtered, based on the rainfall frequency bands. Regression, correlation, and composite analyses are subsequently used to identify the most important rainfall–climate system time-scale relationships.

The results show that Ethiopian monsoon rainfall variation is largely linked with annual time-scale atmospheric circulation patterns involving variability in the major components of the monsoon system. Although variability on the seasonal (75–210 days), quasi-biennial (QB; 1.42–3.04 yr), and El Niño–Southern Oscillation (ENSO; 3.04–4.60 yr) time scales accounts for much less variance than the annual mode (210 days–1.42 yr), they significantly affect Ethiopian rainfall by preferentially modulating the major regional monsoon components and remote teleconnection linkages. The seasonal time scale largely acts in phase with the annual mode, by enhancing or reducing the lower-tropospheric southwesterlies from the equatorial Atlantic during wet or dry periods. The wet QB phase strengthens the Azores and Saharan high and the tropical easterly jet (TEJ) over the Arabian Sea, while the wet ENSO phase enhances the Mascarene high, the TEJ, and the monsoon trough more locally. The effects of tropical SST on Ethiopian rainfall also are prominent on the QB and ENSO time scales. While rainfall–SST correlations for both the QB and ENSO modes are strongly positive (negative) over the equatorial western (eastern) Pacific, only ENSO exhibits widespread strong negative correlations over the Indian Ocean. Opposite QB and ENSO associations tend to characterize dry Ethiopian conditions. The relationships identified on individual time scales now are being used to develop and validate statistical prediction models for Ethiopia.
Efficiency of Mixing Forced by Unsteady Shear Flow
Authors: Inoue Ryuichiro , Smyth William D.
Published: January 2009

The dependence of mixing efficiency on time-varying forcing is studied by direct numerical simulation (DNS) of Kelvin–Helmholtz (KH) instability. Time-dependent forcing fields are designed to reproduce a wavelike oscillation by solving the equations of motion in a tilted coordinate frame and allowing the tilt angle to vary in time. Mixing efficiency Γc is defined as the ratio of potential energy gain to dissipation, both averaged over one forcing cycle and first examined via parameters characterizing waves: the minimum Richardson number Rimin and the normalized frequency of the forcing ω/N. The effect of Reynolds number Re0 and the initial random disturbance amplitude b are also examined. In the experiments presented, Γc varies between 0.21 and 0.36 and is controlled by the timing of two events: the emergence of KH billows and the arrival of the deceleration of the mean shear by the wavelike forcing. Here, Γc is higher than a canonical value of 0.2 when the deceleration phase of the forcing suppresses the less efficient turbulence after breakdown of KH billows. However, when Rimin and ω/N are small, KH billows start to develop before Rimin is achieved. Therefore, the forcing accelerates the mean shear and thereby sustains turbulence after the breakdown of KH billows. The canonical value is then reproduced in the DNS. Although larger values of Re0 and b intensify the development of KH billows and modify Γc, this effect is less significant when forcing fields act to sustain turbulence. The time-averaged Thorpe scale and Ozmidov scale are also used to see how mixing is modified by forcing fields and compared with past microstructure measurements. It is found that DNS also corresponds to past observations if the forcing accelerates the mean shear to sustain turbulence.
Accelerating Dense-Water Flow down a Slope
Authors: Huthnance John M.
Published: January 2009

Where water is denser on a shallow shelf than in the adjacent deep ocean, it tends to flow down the slope from shelf to ocean. The flow can be in a steady bottom boundary layer for moderate combinations of upslope density gradient −ρx∞ and bottom slope (angle θ to horizontal):Here g is acceleration due to gravity, ρ0 is a mean density, and f is twice the component of the earth’s rotation normal to the sloping bottom. For stronger combinations of the horizontal density gradient and bottom slope, the flow accelerates. Analysis of an idealized initial value problem shows that, when b ≥ 1, there is a bottom boundary layer with downslope flow, intensifying exponentially at a rate fb2(1 + b)−1/2/2, and slower-growing flow higher up. For stronger stratification b > 21/2, that is, a relatively weak Coriolis constraint, the idealized problem posed here may not be the most apposite but suggests that the whole water column accelerates, at a rate [ρ0−1|ρx∞|g sinθ]1/2 if f is negligible.
A New Climatology of Air–Sea Density Fluxes and Surface Water Mass Transformation Rates Constrained by WOCE
Authors: Howe Nicola , Czaja Arnaud
Published: January 2009

Global air–sea heat and freshwater flux data, constrained by World Ocean Circulation Experiment (WOCE) hydrographic section transports, is used to construct a new global density flux climatology. Global transformations calculated using this density flux dataset show two regimes: surface waters with density less than ∼1023.3 kg m−3 are transformed to lighter density classes with a maximum rate of 130 Sv (1 Sv ≡ 106 m3 s−1) at σ ∼ 1021.6 kg m−3, and surface waters with density greater than 1023.3 kg m−3 are transformed to denser density classes with a maximum rate of 100 Sv at σ = 1025.4 kg m−3. At higher density (σ = 1027 kg m−3) the net transformation rates vanish, reflecting heat loss in the Northern Hemisphere balanced by Southern Hemisphere freshening. This results in a kink in the global transformation rate, which is attributed to the presence of Drake Passage. Further analysis of the control run of the third Hadley Centre global climate model, HadCM3, suggests this feature to be robust and to reflect the “channel” geometry of the Southern Ocean and the “basin” geometry of the Northern Hemisphere.
A Field Study of Reflectivity and Z–R Relations Using Vertically Pointing Radars and Disdrometers
Authors: Tokay Ali , Hartmann Peter , Battaglia Alessandro , Gage Kenneth S. , Clark Wallace L. , Williams Christopher R.
Published: January 2009

Observations from a 16-month field study using two vertically pointing radars and a disdrometer at Wallops Island are analyzed to examine the consistency of the multi-instrument observations with respect to reflectivity and Z–R relations. The vertically pointing radars were operated at S and K bands and had a very good agreement in reflectivity at a gate centered on 175 and 177 m above ground level over a variety of storms. This agreement occurred even though the sampling volumes were of different size and even though the S band measured the reflectivity factor directly, whereas the K-band radar deduced it from attenuated K-band measurements. Indeed, the radar agreement in reflectivity at the collocated range gates was superior to that between the disdrometer and either radar. This is attributed in large part to the spatial separation of the disdrometer and radar sample volumes, although the lesser agreement observed in a prior collocated disdrometer–disdrometer comparison suggests the larger size of the radar sample volumes as well as the better overlap also play a role. Vertical variations in the observations were examined with the aid of the two radar profilers. As expected, the agreement between the disdrometer reflectivity and the reflectivity seen in the vertically pointing radars decreased with height. The effect of these vertical variations on determinations of Z–R relation coefficients was then examined, using a number of different methods for finding the best-fitting coefficients. The coefficient of the Z–R relation derived from paired disdrometer rain rate and radar reflectivity decreased with height, while the exponent of the Z–R relation increased with height. The coefficient and exponent of the Z–R relations also showed sensitivity to the choice of derivation method [linear and nonlinear least squares, fixed exponent, minimizing the root-mean-square difference (RMSD), and probability matching]. The influence of the time lag between the radar and disdrometer measurements was explored by examining the RMSD in reflectivity for paired measurements between 0- and 4-min lag. The no-lag conditions had the lowest RMSD up to 400 m, while 1-min lag gave the lowest RMSD at higher heights. The coefficient and exponent of the Z–R relations, on the other hand, did not have a significant change between no-lag- and 1-min-lag-based pairs.
Construction of the Remote Sensing Systems V3.2 Atmospheric Temperature Records from the MSU and AMSU Microwave Sounders
Authors: Mears Carl A. , Wentz Frank J.
Published: January 2009

Measurements made by microwave sounding instruments provide a multidecadal record of atmospheric temperature change. Measurements began in late 1978 with the launch of the first Microwave Sounding Unit (MSU) and continue to the present. In 1998, the first of the follow-on series of instruments—the Advanced Microwave Sounding Units (AMSUs)—was launched. To continue the atmospheric temperature record past 2004, when measurements from the last MSU instrument degraded in quality, AMSU and MSU measurements must be intercalibrated and combined to extend the atmospheric temperature data records. Calibration methods are described for three MSU–AMSU channels that measure the temperature of thick layers of the atmosphere centered in the middle troposphere, near the tropopause, and in the lower stratosphere. Some features of the resulting datasets are briefly summarized.
Computationally Efficient Methods of Collocating Satellite, Aircraft, and Ground Observations
Authors: Nagle Frederick W. , Holz Robert E.
Published: January 2009

The usefulness of measurements from satellite-borne instruments is enhanced if these measurements can be compared to measurements from other instruments mounted aboard the same or different satellite, with measurements from aircraft, or with ground measurements. The process of associating measurements from disparate instruments and platforms is referred to as collocation. In a few cases, two instruments mounted aboard the same spacecraft have been engineered to function in tandem, but commonly this is not the case. The collocation process may then become an awkward geometric problem of finding which of many observations within one dataset corresponds to an observation in another set, possibly from another platform. This paper presents methods that can be applied to a wide range of satellite, aircraft, and surface measurements that allow for efficient collocation with measurements having varying spatial and temporal sampling. Examples of applying the methods are presented that highlight the benefits of efficient collocation. This includes identifying the occurrence of simultaneous nadir observations (SNOs); collocation of sounder, imager, and active remotely sensed measurements on the NASA Earth Observation System (EOS); and collocation of the polar orbiting imager, sounder, and microwave measurements with geostationary observations. It is possible, using an inexpensive laptop computer, to collocate Moderate Resolution Imaging Spectroradiometer (MODIS) imager observations from the Aqua satellite with geostationary observations rapidly enough to deal with these measurements in real time, making either dataset, enhanced by the other, a potentially operational product. A “tool kit” is suggested consisting of computer procedures useful in collocation.
Development and Forcing of the Rear Inflow Jet in a Rapidly Developing and Decaying Squall Line during BAMEX
Authors: Grim Joseph A. , Rauber Robert M. , McFarquhar Greg M. , Jewett Brian F. , Jorgensen David P.
Published: January 2009

This study examines the development, structure, and forcing of the rear inflow jet (RIJ) through the life cycle of a small, short-lived squall line over north-central Kansas on 29 June 2003. The analyses were developed from airborne quad-Doppler tail radar data from the NOAA and NRL P-3 aircraft, obtained over a 2-h period encompassing the formation, development, and decay of the squall line during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX). The strengthening of the system-relative rear inflow to 17 m s−1 was concurrent with the formation of a bow echo, an increased dynamic pressure gradient beneath the rearward-tilted updraft, and two counterrotating vortices at either end of the bow. The later weakening of the RIJ to 8 m s−1 was concurrent with the weakening of the bow, a decreased dynamic pressure gradient at midlevels behind the bow, and the weakening and spreading of the vortices. In a modeling study, Weisman quantified the forcing mechanisms responsible for the development of an RIJ. This present study is the first to quantitatively analyze these mechanisms using observational data. The forcing for the horizontal rear inflow was analyzed at different stages of system evolution by evaluating the contributions of four forcing mechanisms: 1) the horizontal pressure gradient resulting from the vertical buoyancy distribution (δPB), 2) the dynamic pressure gradient induced by the circulation between the vortices (δPV), 3) the dynamic irrotational pressure gradient (δPI), and 4) the background synoptic-scale dynamic pressure gradient (δPS). During the formative stage of the bow, δPI was the strongest forcing mechanism, contributing 50% to the rear inflow. However, during the mature and weakening stages, δPI switched signs and opposed the rear inflow while the combination of δPB and δPV accounted for at least 70% of the rear inflow. The δPS forced 4%–25% of the rear inflow throughout the system evolution.
Ensemble Regression
Authors: Unger David A. , van den Dool Huug , O’Lenic Edward , Collins Dan
Published: January 2009

A regression model was developed for use with ensemble forecasts. Ensemble members are assumed to represent a set of equally likely solutions, one of which will best fit the observation. If standard linear regression assumptions apply to the best member, then a regression relationship can be derived between the full ensemble and the observation without explicitly identifying the best member for each case. The ensemble regression equation is equivalent to linear regression between the ensemble mean and the observation, but is applied to each member of the ensemble. The “best member” error variance is defined in terms of the correlation between the ensemble mean and the observations, their respective variances, and the ensemble spread. A probability density function representing the ensemble prediction is obtained from the normalized sum of the best-member error distribution applied to the regression forecast from each ensemble member. Ensemble regression was applied to National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS) forecasts of seasonal mean Niño-3.4 SSTs on historical forecasts for the years 1981–2005. The skill of the ensemble regression was about the same as that of the linear regression on the ensemble mean when measured by the continuous ranked probability score (CRPS), and both methods produced reliable probabilities. The CFS spread appears slightly too high for its skill, and the CRPS of the CFS predictions can be slightly improved by reducing its ensemble spread to about 0.8 of its original value prior to regression calibration.
Control of Porosity and Expansion in Starch Extrusion by Monitoring Pressure at Die Outlet
Authors: Plews Andrew G. , Atkinson Alan , Trampe Torsten , Mcgrane Scott
Published: January 2009

Pore structure of starch extrudates is an important area of study in the food industry. Usually, changes in porosity also results in variations in skeletal material due to influence from degree of cook and type of cook (e.g., pure gelatinization vs. mechanical degradation). However, changing the pressure differential across the extruder die face provides a method by which expansion is controlled without influencing the skeletal material. Results from this study have shown that the volume fraction porosity can be varied from 0.23 to 0.53 with negligible effect on skeletal density. The expansion control method does not control pore sizes with distributions and means having an element of randomness. However, average pore wall thickness is linearly related to the pressure differential across the die face with a reduced pressure differential giving increased pore wall thickness and vice versa. Thus, controlled expansion can be used to produce products/samples that have the same skeletal material but different average pore wall thickness and total porosity.
Affective and Sensory Correlates of Hair Pulling in Pediatric Trichotillomania
Authors: Meunier Suzanne A. , Tolin David F. , Franklin Martin
Published: January 2009

Hair pulling in pediatric populations has not received adequate empirical study. Investigations of the affective and sensory states contributing to the etiology and maintenance of hair pulling may help to elucidate the classification of trichotillomania (TTM) as an impulse control disorder or obsessive-compulsive spectrum disorder. The current study aimed to examine children's self-reported affective and sensory states associated with hair pulling. Fifteen participants completed a questionnaire assessing children's experiences during first and recent hair pulling episodes. Results revealed that pulling hair for the first time was associated with pleasure and pain whereas recent hair pulling was associated with pleasure only, suggesting that the punishing quality of hair pulling may diminish over time. The findings also support the notion that hair pulling may be maintained primarily through positive reinforcement, which is consistent with its classification as an impulse control disorder.
Evaluation of a Self-Instructional Manual for Conducting Discrete-Trials Teaching With Children With Autism
Authors: Thiessen Carly , Fazzio Daniela , Arnal Lindsay , Martin Garry L. , Yu C.T. , Keilback Lukas
Published: January 2009

Discrete-trials teaching (DTT) is commonly used to implement applied behavior analysis treatment for children with autism. The authors investigated a revised self-instructional manual for teaching university students to implement a 21-component DTT procedure to teach three tasks to confederates role-playing children with autism. Also, as a motivational contingency, for each DTT session in which a student scored at or above 90% accuracy, they received US$10. After an average of 4.5 hr to master the training manual, students' average DTT performance improved from 52% in baseline to 88% while teaching a confederate. Students averaged 77% DTT performance during subsequent generalization sessions with a child with autism.
Creative Terror Management: Creativity as a Facilitator of Cultural Exploration After Mortality Salience
Authors: Routledge Clay D. , Arndt Jamie
Published: January 2009

Research indicates that people respond to the elicitation of death thoughts by dogmatically defending their cultural worldviews. The current research examines the potential for conditions of creativity, a construct associated with open-mindedness, to promote a more explorative reaction to the threat of death thoughts. In Studies 1 and 2, thoughts of death or a control topic were activated and then participants engaged in either a creative or a control task. In Study 3, thoughts of death or a control topic were activated and then participants were presented with information suggesting that creativity is or is not culturally valued. After these conditions, social, intellectual, and environmental exploration (Study 1) and cultural worldview exploration (Studies 2 and 3) were measured. Results indicated that both engaging in a creative task and being informed that creativity is culturally valued facilitated exploration in response to thinking about death. Conceptual and applied implications are discussed.
Thermal-mechanical Analysis of Satin Weave CFRP Composites with Cracks at Cryogenic Temperatures
Authors: Watanabe Shinya , Shindo Yasuhide , Narita Fumio , Takeda Tomo
Published: January 2009

This study deals with the thermal-mechanical behavior of satin weave carbon fiber-reinforced polymer (CFRP) laminates with internal and/or edge cracks and temperature-dependent material properties under tension at cryogenic temperatures. Cracks are assumed to be located in the transverse fiber bundles and extend to the interfaces between two fiber bundles. Young's modulus and stress distributions near the crack tip under combined mechanical and thermal loads are predicted by finite element models that assume generalized plane strain. The effects of residual thermal stresses and cracks on the mechanical behavior of CFRP woven laminates at cryogenic temperatures are calculated, and the numerical results are presented in graphical form.
Analysis of chloroethane toxicity and carcinogenicity including a comparison with bromoethane
Authors: Holder JW
Published: January 2009

Chloroethane (CE) gas carcinogenicity is analyzed and determined from a National Toxicology Program (NTP) bioassay where an inhalation concentration of 15,000 ppm CE gas in air produced the highest incidence of an uncommon-to-rare tumor ever observed by the NTP. Persistently inhaled CE produces endometrial cancers in female mice. The first-tumor-corrected uterine endometrial incidence (I) in B6C3F1 mice is 90%, but no significant tumors occurred in F344 rats. The endometrial cancers dispersed by 1) migrating locally to the adjacent myometrium, 2) then migrating to the bloodstream by intravasation, 3) entering 17 distal organs by extravasation and adapting to the new tissue environment. Distal cancers retained sufficient endometrial cell features to be recognized at each metastatic site. CE produced one of the highest metastasis rates ever observed by NTP of 79%. Comparing CE with bromoethane (BE), a structural analogue, it was found that BE too produced rare murine endometrial cancers yielding the second highest NTP incidence rate of I = 58% with a similar high malignancy rate of 56%. Because of the historical rarity of endometrial tumors in the B6C3F1 mouse, both of these SAR haloethanes seem to be evoking a strong, related carcinogenic potential in B6C3F1 mice, but not in F344 rats. The question of whether humans are similar to mice or to rats is addressed here and in Gargas, et al., 2008. The powerful carcinogenesis caused by these halohydrocarbons may have been caused by excessive and metabolically unresolved acetaldehyde (AC) which is directly generated by Cyp2E1 in the oxidative elimination of CE. With >95% AC metabolic production, as predicted from pharmacokinetic (PK) studies depending on CE exposure, AC is the main elimination intermediate. AC is a known animal carcinogen and a strongly suspected human carcinogen. Also, CE causes incipient decreases of tissue essential glutathione pools [GSH] by Phase II conjugation metabolic elimination of CE (and BE), by glutantione transferase (GST), in most organs (except brain) exposed to high circulating CE and it metabolites. In three laboratories, an excessive stress reaction of hyperkinesis was observed only during 15,000 ppm gas exposure but not when the exposure ceased or when exposure was presented at 150 ppm. Test rodents other than the female mice did not exhibit a pattern of visible stress nor did they have a carcinogenic response to CE gas. Unremitting stress has been documented to contribute a feedback to the hypothalamus which stimulates the hypothalamic-pituitary-axis (HPA), which in turn, induces the adrenal glands. Because estrus and estrogen and progesterone levels were unaltered by CE gas, the adrenal over stimulation, causing high steroid output, may be the penultimate step in this extraordinary carcinogenic response. High adrenal production of corticosteroids could adversely promote endometrial cells to cancers in mice − a mechanism that has already been observed in humans.
Cluster of Hodgkin’s lymphoma in residents near a non-operational petroleum refinery
Authors: Dahlgren J , Klein J , Takhar H
Published: January 2009

This report examines the prevalence rate of Hodgkin’s disease in an American mid-west town located directly south of a non-operational oil refinery. The refinery has a history of benzene-containing gasoline leaks dating back to the early 1900s. Exposure data were assessed through the Toxic Release Inventory (TRI) data as published by the Environmental Protection Agency (EPA) and supplemented by exposure simulations using variations of residential exposure times and odour levels and the benzene content of the gasoline. Prevalence rates depended on the size of the population in question. The population size varied greatly between sources, with the more conservative and consistent estimates being reported by the local government and United States Census Bureau and the highest population figure being reported by the Agency for Toxic Substances Disease Registry. The prevalence of Hodgkin’s disease for the residents within 1 mile from the refinery was found to be elevated for every population figure, ranging from 72.11 cases per 100,000 using the ATSDR’s population to 182.34 per 100,000, whereas the prevalence for Hodgkin’s disease in all the United States is only 22 cases of Hodgkin’s disease per 100,000 people. The prevalence value reported in this report should be given greater weight than what would have been calculated using data from the ATSDR. Because of its significantly increased value compared with the rest of the United States, it provides evidence of benzene’s role as a causative agent in the etiology of Hodgkin’s disease.
Deleterious effects induced by oxidative stress in liver nuclei from rats receiving an alcohol-containing liquid diet
Authors: Díaz Gómez MI , Fanelli SL , Delgado de Layño AMA , Bietto FM , Castro JA , Castro GD
Published: January 2009

Highly purified rat-liver nuclei were previously shown to have nuclear ethanol (EtOH) metabolizing system able to bioactivate alcohol to acetaldehyde and 1-hydroxyethyl radicals. These reactive metabolites were able to covalently bind to nuclear proteins and lipids potentially being able to provoke oxidative stress of nuclear components. In this study, the above-mentioned possibility was explored. Sprague Dawley male rats (125–150 g) were fed a standard Lieber and De Carli liquid diet for 28 days. Controls were pair-fed with a diet, in which EtOH was isocalorically replaced with carbohydrate. The presence of a chlorzoxazone hydroxylase activity inducible by the repetitive EtOH drinking further suggested the presence of CYP2E1 in the highly purified nuclei. Nuclei from EtOH-drinking rats evidenced significantly increased susceptibility to a t-butyl hydroperoxide challenge as detected by chemiluminescence emission, increased formation of protein carbonyls, and decreased content of protein sulfhydryls. In contrast, no significant changes in the nuclear lipid hydroperoxides formation or even decreases in the 8-oxo-7,8-dihydro-2-deoxyguanosine were observed. No significant differences were observed in different parameters of the alkaline Comet assay. In immunohistochemical studies performed, no expression of p53 was observed in the livers of the animals under the experimental conditions tested. Since nuclear proteins and lipids are known to play a role in cell growth, differentiation, repair and signaling, their alterations by either oxidative stress, or by covalent binding might be of relevance to liver tumor promotion.
Endogenous lipid pneumonia in rats after subacute exposure to CdCl2
Authors: Molina AM , Raya AI , Carrasco L , Blanco A , Monterde JG , Rueda A , Moyano R
Published: January 2009

The objective of this report was to study lung cellular lesions in Wistar rats after subacute oral exposition to CdCl2. The experimental groups were exposed to CdCl2, through their drinking water in a concentration of 1 g/L, continuously for a period of 9 days. Histologically, all the exposed animals showed the incidence of interstitial pneumonia; hyperplasia of type II pneumocytes and Clara cells; the presence of foamy macrophages; and lesions linked to the existence of endogenous lipid pneumonia. Endogenous lipid pneumonia after CdCl2 exposure has not been previously described; and in its pathogenesis, hyperplasia of type II pneumocytes and Clara cells activation could play an important role.
Influence of alpha lipoic acid on antioxidant status in D-galactosamine-induced hepatic injury
Authors: Shanmugarajan TS , Sivaraman D , Somasundaram I , Arunsundar M , Krishnakumar E , Balaji R , Ravichandiran V
Published: January 2009

D-Galactosamine (GalN)-induced liver injury is associated with reactive oxygen species and oxidative stress. In the present study, we evaluated the effect of alpha lipoic acid (ALA) supplementation on acute GalN-induced oxidative liver injury. Hepatotoxicity induced by single intraperitoneal injection of GalN (500 mg/kg body wt) was evident from increase in lipid peroxidation and serum marker enzymes (asparate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase). The decreased activities of enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) as well as glutathione levels were the salient features observed in GalN-induced hepatotoxicity. Pretreatment with ALA (50 mg/kg body weight for 7 days) significantly precluded these changes and prevents the hepatic injury. Hence, this study clearly exemplified that ALA might be a suitable candidate against GalN-induced cellular abnormalities.