bluuebunny/crossref_metadata_2025 huggingface dataset:
RGS6, a Modulator of Parasympathetic Activation in Heart
Authors: Yang Jianqi , Huang Jie , Maity Biswanath , Gao Zhan , Lorca Ramón A. , Gudmundsson Hjalti , Li Jingdong , Stewart Adele , Swaminathan Paari Dominic , Ibeawuchi Stella-Rita , Shepherd Andrew , Chen Ching-Kang , Kutschke William , Mohler Peter J. , Mohapatra Durga P. , Anderson Mark E. , Fisher Rory A.
Published: September 2010

Rationale:

Parasympathetic regulation of heart rate is mediated by acetylcholine binding to G protein–coupled muscarinic M2 receptors, which activate heterotrimeric G
i/o
proteins to promote G protein–coupled inwardly rectifying K
+
(GIRK) channel activation. Regulator of G protein signaling (RGS) proteins, which function to inactivate G proteins, are indispensable for normal parasympathetic control of the heart. However, it is unclear which of the more than 20 known RGS proteins function to negatively regulate and thereby ensure normal parasympathetic control of the heart.

Objective:

To examine the specific contribution of RGS6 as an essential regulator of parasympathetic signaling in heart.

Methods and Results:

We developed RGS6 knockout mice to determine the functional impact of loss of RGS6 on parasympathetic regulation of cardiac automaticity. RGS6 exhibited a uniquely robust expression in the heart, particularly in sinoatrial and atrioventricular nodal regions. Loss of RGS6 provoked dramatically exaggerated bradycardia in response to carbachol in mice and isolated perfused hearts and significantly enhanced the effect of carbachol on inhibition of spontaneous action potential firing in sinoatrial node cells. Consistent with a role of RGS6 in G protein inactivation, RGS6-deficient atrial myocytes exhibited a significant reduction in the time course of acetylcholine-activated potassium current (
I
K
ACh
) activation and deactivation, as well as the extent of
I
K
ACh
desensitization.

Conclusions:

RGS6 is a previously unrecognized, but essential, regulator of parasympathetic activation in heart, functioning to prevent parasympathetic override and severe bradycardia. These effects likely result from actions of RGS6 as a negative regulator of G protein activation of GIRK channels.
Severity of Dilated Virchow-Robin Spaces Is Associated With Age, Blood Pressure, and MRI Markers of Small Vessel Disease
Authors: Zhu Yi-Cheng , Tzourio Christophe , Soumaré Aïcha , Mazoyer Bernard , Dufouil Carole , Chabriat Hugues
Published: September 2010

Background and Purpose—

Little is known about the risk factors of dilated Virchow-Robin spaces (dVRS) and their relation with other markers of brain small vessel disease. We investigated both issues in a large population-based sample of elderly individuals.

Methods—

Severity of dVRS was semiquantitatively graded in both white matter and basal ganglia using high-resolution 3-dimensional MRI images taken from 1818 stroke- and dementia-free subjects enrolled in the Three-City Dijon MRI study. Multinomial logistic regression models were used to model the association of cardiovascular risk factors, APOE genotype, brain atrophy, and MRI markers of small vessel disease with the degree of dVRS.

Results—

Severity of dVRS was found to be strongly associated with age in both basal ganglia (degree 4 versus 1: OR, 2.1; 95% CI, 1.4 to 3.2) and white matter (OR, 1.5; 95% CI, 1.2 to 1.9). The proportion of hypertensive subjects increased with the degrees of dVRS in both basal ganglia (
P
=0.02) and white matter (
P
=0.048). Men presented a higher risk of severe dVRS in basal ganglia than women, particularly degree 4 (OR, 6.0; 95% CI, 1.8 to 19.8). The degree of dVRS was associated with the volume of white matter hyperintensities and the prevalence of lacunes, but not with brain atrophy.

Conclusion—

In this large cohort study of elderly subjects, the degree of dVRS appears independently associated with age, hypertension, volume of white matter hyperintensities, and lacunar infarctions. dVRS should be considered as another MRI marker of cerebral small vessel disease in the elderly with regional variations in their severity.
Analysis of (1+1) Evolutionary Algorithm and Randomized Local Search with Memory
Authors: Sung Chi Wan , Yuen Shiu Yin
Published: September 2010

This paper considers the scenario of the (1+1) evolutionary algorithm (EA) and randomized local search (RLS) with memory. Previously explored solutions are stored in memory until an improvement in fitness is obtained; then the stored information is discarded. This results in two new algorithms: (1+1) EA-m (with a raw list and hash table option) and RLS-m+ (and RLS-m if the function is a priori known to be unimodal). These two algorithms can be regarded as very simple forms of tabu search. Rigorous theoretical analysis of the expected time to find the globally optimal solutions for these algorithms is conducted for both unimodal and multimodal functions. A unified mathematical framework, involving the new concept of spatially invariant neighborhood, is proposed. Under this framework, both (1+1) EA with standard uniform mutation and RLS can be considered as particular instances and in the most general cases, all functions can be considered to be unimodal. Under this framework, it is found that for unimodal functions, the improvement by memory assistance is always positive but at most by one half. For multimodal functions, the improvement is significant; for functions with gaps and another hard function, the order of growth is reduced; for at least one example function, the order can change from exponential to polynomial. Empirical results, with a reasonable fitness evaluation time assumption, verify that (1+1) EA-m and RLS-m+ are superior to their conventional counterparts. Both new algorithms are promising for use in a memetic algorithm. In particular, RLS-m+ makes the previously impractical RLS practical, and surprisingly, does not require any extra memory in actual implementation.
Evaluation of the Research-Version TMPA Rainfall Estimate at Its Finest Spatial and Temporal Scales over the Rome Metropolitan Area
Authors: Villarini Gabriele
Published: September 2010

The focus of this study is the evaluation of the research-version Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) rainfall product at its finest spatial and temporal resolutions (3-hourly and 0.25° × 0.25°) over the Rome, Italy, metropolitan area during the period from October 2008 to January 2009. Accurate ground reference rainfall estimates for two satellite pixels are obtained from a dense rain gauge network (22 rain gauges in one pixel and 16 in the other one). The evaluation is based on examination of time series, scatterplots, and survival functions, as well as measures of agreement and disagreement. The results of this study point to the importance of using the TRMM satellite for rainfall estimation. Suggestions in terms of minimum number of rain gauges required to estimate ground reference rainfall are also provided.
Characteristics of CALIPSO and CloudSat Backscatter at the Top Center Layers of Mesoscale Convective Systems and Relation to Cloud Microphysics
Authors: Platt C. M. R. , Vaughan M. A. , Austin R. T.
Published: September 2010

Following the discovery of anomalously high values of lidar integrated attenuated backscatter near the top center layers of mesoscale convective systems (MCSs) observed by the NASA Lidar In-Space Technology Experiment (LITE), a search of Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) data on board the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) platform revealed the same phenomena in a sample of eight MCSs investigated. The backscatter depolarization ratio also showed changes concurrent with the high integrated backscatter and either increased or decreased concurrently with the anomalous backscatter. Simultaneous CloudSat data in the A-Train formation showed a cloud-top altitude similar to that measured by CALIOP, indicating fairly large ice crystals were reaching cloud top. Based on previous work, the CALIOP and CloudSat returns were likely due to a mix of small ice droxtals or frozen drops extending in a continuous spectrum to large crystals composed of well-formed hexagonal columns, thick hexagonal plates, spheroids, and irregular particles. The CALIOP lidar would detect the whole spectrum whereas CloudSat would detect ice crystals greater than ∼30 μm in effective radius; there were apparently enough of such crystals to allow CloudSat to detect a cloud-top height similar to that found by CALIOP. Using such a model, it was estimated that the measured backscatter phase function in the most active part of the cloud could be reconciled approximately with theoretical values of the various crystal habits. However, it was harder to reconcile the changes in depolarization ratio given the absence of values of this parameter for small droxtal crystals.
Bred Vector and ENSO Predictability in a Hybrid Coupled Model during the Period 1881–2000
Authors: Tang Youmin , Deng Ziwang
Published: September 2010

In this study, a breeding analysis was conducted for a hybrid coupled El Niño–Southern Oscillation (ENSO) model that assimilated a historic dataset of sea surface temperature (SST) for the 120 yr between 1881 and 2000. Meanwhile, retrospective ENSO forecasts were performed for the same period. For a given initial state, 15 bred vectors (BVs) of both SST and upper-ocean heat content (HC) were derived. It was found that the average structure of the 15 BVs was insensitive to the initial states and independent of season and ENSO phase. The average structure of the BVs shared many features already seen in both the final patterns of leading singular vectors and the ENSO BVs of other models. However, individual BV patterns were quite different from case to case. The BV rate (the average cumulative growth rate of BVs) varied seasonally, and the maximum value appeared at the time when the model ran through the boreal spring and summer. It was also sensitive to the strength of the ENSO signal (i.e., the stronger ENSO signal, the smaller the BV rate).

Furthermore, ENSO predictability was explored using BV analysis. Emphasis was placed on the relationship between BVs, which are able to characterize potential predictability without requiring observations, and actual prediction skills, which make use of real observations. The results showed that the relative entropy, defined using breeding vectors, was a good measure of potential predictability. Large relative entropy often leads to a good prediction skill; however, when the relative entropy was small, the prediction skill seemed much more variable. At decadal/interdecadal scales, the variations in prediction skills correlated with relative entropy.
Circulation Mechanisms of Kenya Rainfall Anomalies
Authors: Hastenrath Stefan , Polzin Dierk , Mutai Charles
Published: September 2010

Expanding earlier studies on the boreal spring and autumn rainy seasons in equatorial East Africa, pending challenges on the mechanisms of rainfall variability, are investigated. Eastward pressure gradient and slack south Indian Ocean trade winds allow surface equatorial westerlies in spring and autumn. Complementing that, upper-tropospheric easterlies are required for the development of a zonal vertical circulation cell along the Indian Ocean equator. Because of the summer warming and high stand of upper-tropospheric topography over South Asia, strong upper-tropospheric easterlies over the tropical northern and equatorial Indian Ocean persist from summer into autumn, thus allowing the development of a zonal vertical circulation cell. By contrast, the winter cooling entails low stand of upper-tropospheric topography in the north, thus hindering easterlies over the equator. Consequently, an equatorial zonal circulation cell does not develop in boreal spring. The equatorial zonal circulation cell, with subsidence over East Africa, strongly controls the boreal autumn rains, as evidenced in their tight correlation with the equatorial westerlies. In a related vein, rain gauge stations show much shared variance in boreal autumn as compared to spring. Plausibly consistent with this, boreal autumn rather than spring has brought the extreme flood and drought disasters in the course of the past half-century.
On the Persistence and Predictability Properties of North Atlantic Climate Variability
Authors: Franzke Christian , Woollings Tim
Published: September 2010

The persistence and climate noise properties of North Atlantic climate variability are of importance for trend identification and assessing predictability on all time scales from several days to many decades. Here, the authors analyze these properties by applying empirical mode decomposition to a time series of the latitude of the North Atlantic eddy-driven jet stream. In previous studies, it has been argued that a slow decay of the autocorrelation function at large lags suggests potential extended-range predictability during the winter season. The authors show that the increased autocorrelation time scale does not necessarily lead to enhanced intraseasonal predictive skill. They estimate the fraction of interannual variability that likely arises due to climate noise as 43%–48% in winter and 70%–71% in summer. The analysis also indentifies a significant poleward trend of the jet stream that cannot be explained as arising from climate noise. These findings have important implications for the predictability of North Atlantic climate variability.
Projected Future Seasonal Changes in Tropical Summer Climate
Authors: Sobel Adam H. , Camargo Suzana J.
Published: September 2010

The authors analyze changes in the tropical sea surface temperature (SST), surface wind, and other fields from the twentieth to the twenty-first century in climate projections using the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel ensemble, focusing on the seasons January–March (JFM) and July–September (JAS). When the annual mean change is subtracted, the remaining “seasonal changes” have robust, coherent structures. The JFM and JAS changes resemble each other very closely after either a change of sign or reflection about the equator. The seasonal changes include an increase in the summer hemisphere SST and a decrease in the winter hemisphere SST. These appear to be thermodynamic consequences of easterly trade winds strengthening in the winter subtropics and weakening in the summer subtropics. These in turn are associated with the weakening and expansion of the Hadley circulation, documented by previous studies, which themselves are likely consequences of changes in extratropical eddies. The seasonal SST changes influence the environment for deep convection: peak precipitation in the summer hemisphere increases by around 10% and convective available potential energy (CAPE) increases by as much as 25%. Comparable fractions of these changes are attributable to the annual mean change and the seasonal changes, though the two have very different spatial structures. Since the annual mean change is marked by relative warming in the Northern Hemisphere compared to the Southern Hemisphere, the seasonal changes oppose the annual mean change in JFM and enhance it in JAS.
Stratospheric Ozone Depletion: The Main Driver of Twentieth-Century Atmospheric Circulation Changes in the Southern Hemisphere
Authors: Polvani Lorenzo M. , Waugh Darryn W. , Correa Gustavo J. P. , Son Seok-Woo
Published: September 2010

The importance of stratospheric ozone depletion on the atmospheric circulation of the troposphere is studied with an atmospheric general circulation model, the Community Atmospheric Model, version 3 (CAM3), for the second half of the twentieth century. In particular, the relative importance of ozone depletion is contrasted with that of increased greenhouse gases and accompanying sea surface temperature changes. By specifying ozone and greenhouse gas forcings independently, and performing long, time-slice integrations, it is shown that the impacts of ozone depletion are roughly 2–3 times larger than those associated with increased greenhouse gases, for the Southern Hemisphere tropospheric summer circulation. The formation of the ozone hole is shown to affect not only the polar tropopause and the latitudinal position of the midlatitude jet; it extends to the entire hemisphere, resulting in a broadening of the Hadley cell and a poleward extension of the subtropical dry zones. The CAM3 results are compared to and found to be in excellent agreement with those of the multimodel means of the recent Coupled Model Intercomparison Project (CMIP3) and Chemistry–Climate Model Validation (CCMVal2) simulations. This study, therefore, strongly suggests that most Southern Hemisphere tropospheric circulation changes, in austral summer over the second half of the twentieth century, have been caused by polar stratospheric ozone depletion.
The Seasonal Structure of Temperature Trends in the Tropical Lower Stratosphere
Authors: Free Melissa
Published: September 2010

Radiosonde data show a large seasonal difference in trends since 1979 in the tropical lower stratosphere, with a maximum cooling of ∼1 K decade−1 in December and January and a minimum in March or April at 50 mb between 10°N and 10°S. The statistically significant difference of up to ∼1 K decade−1 between trends in December and those in March amounts to up to 20% of the climatological seasonal cycle. Although the size of annual mean cooling trends differs substantially among datasets, the seasonal pattern of trends is similar in all six radiosonde datasets used here and is consistent with MSU satellite data for the lower stratosphere. This greater cooling in boreal winter essentially disappears below 100 mb, and the troposphere has a different and smaller seasonal trend pattern.

Trends in the tropical stratosphere show an inverse relationship with those in the Arctic for 1979–2009, which might be related to changes in stratospheric circulation. In most radiosonde data, however, the seasonal pattern of tropical trends at 50 mb since 1979 seems to come from a seasonal difference in the size of the stratospheric cooling in the mid-1990s, and trends for longer time periods or those for 1995–2009 do not show the same seasonal dependence. Whether the strengthening of the seasonal cycle in the stratosphere represents a long-term change related to greenhouse gas forcing, a shorter-lived shift related to ozone depletion or unforced interdecadal variability requires careful further study.
Instabilities in an Internal Solitary-like Wave on the Oregon Shelf
Authors: Lamb Kevin G. , Farmer David
Published: September 2010

Observations of internal solitary-like waves (ISWs) on the Oregon Shelf suggest the presence of Kelvin–Helmholtz billows in the pycnocline and larger-scale overturns at the back of the wave above the pycnocline. Numerical simulations designed to explore the mechanisms responsible for these features in one particular wave reveal that shear instabilities occur when (i) the minimum Richardson number Ri in the pycnocline is less than about 0.1; (ii) Lx/λ > 0.8, where Lx is the length of the unstable region with Ri < 0.25 and λ is a half wavelength of the wave; and (iii) a linear spatial stability analysis predicts that ln(af/ai) >≈ 4, where ai and af are the amplitudes of perturbations entering and leaving the unstable region. The maximum energy loss rate in our simulations is 50 W m−1, occurring at a frequency 8% below that with the maximum spatial growth rate.

The observations revealed the presence of anomalously light fluid in the center of the wave above the pycnocline. Simulations of a wave encountering a patch of light surface water were used to model this effect. In the presence of a background current with near-surface shear, the simulated ISW has a trapped surface core. As this wave encounters a patch of lighter surface water, the light surface water at first passes beneath the core. Convective instabilities set in and the light fluid is entrained into the core. This results in the formation of overturning features, which exhibit some similarities with the observed overturns.
Improving Satellite-Derived Sea Surface Temperature Accuracies Using Water Vapor Profile Data
Authors: Barton Ian J.
Published: September 2010

Analyses based on atmospheric infrared radiative transfer simulations and collocated ship and satellite data are used to investigate whether knowledge of vertical atmospheric water vapor distributions can improve the accuracy of sea surface temperature (SST) estimates from satellite data. Initially, a simulated set of satellite brightness temperatures generated by a radiative transfer model with a large maritime radiosonde database was obtained. Simple linear SST algorithms are derived from this dataset, and these are then reapplied to the data to give simulated SST estimates and errors. The concept of water vapor weights is introduced in which a weight is a measure of the layer contribution to the difference between the surface temperature and that measured by the satellite. The weight of each atmospheric layer is defined as the layer water vapor amount multiplied by the difference between the SST and the midlayer temperature. Satellite-derived SST errors are then plotted against the difference in the sum of weights above an altitude of 2.5 km and that below. For the simple two-channel (with typical wavelengths of 11 and 12 μm) analysis, a clear correlation between the weights differences and the SST errors is found.

A second group of analyses using ship-released radiosondes and satellite data also show a correlation between the SST errors and the weights differences. The analyses suggest that, for an SST derived using a simple two-channel algorithm, the accuracy may be improved if account is taken of the vertical distribution of water vapor above the ocean surface. For SST estimates derived using algorithms that include data from a 3.7-μm channel, there is no such correlation found.
Multiwavelet Discontinuous Galerkin-Accelerated Exact Linear Part (ELP) Method for the Shallow-Water Equations on the Cubed Sphere
Authors: Archibald Rick , Evans Katherine J. , Drake John , White James B.
Published: September 2010

In this paper a new approach is presented to increase the time-step size for an explicit discontinuous Galerkin numerical method. The attributes of this approach are demonstrated on standard tests for the shallow-water equations on the sphere. The addition of multiwavelets to the discontinuous Galerkin method, which has the benefit of being scalable, flexible, and conservative, provides a hierarchical scale structure that can be exploited to improve computational efficiency in both the spatial and temporal dimensions. This paper explains how combining a multiwavelet discontinuous Galerkin method with exact-linear-part time evolution schemes, which can remain stable for implicit-sized time steps, can help increase the time-step size for shallow-water equations on the sphere.
Evaluation of Probabilistic Quality and Value of the ENSEMBLES Multimodel Seasonal Forecasts: Comparison with DEMETER
Authors: Alessandri Andrea , Borrelli Andrea , Navarra Antonio , Arribas Alberto , Déqué Michel , Rogel Philippe , Weisheimer Antje
Published: September 2010

The performance of the new multimodel seasonal prediction system developed in the framework of the European Commission FP7 project called ENSEMBLE-based predictions of climate changes and their impacts (ENSEMBLES) is compared with the results from the previous project [i.e., Development of a European Multimodel Ensemble System for Seasonal-to-Interannual Prediction (DEMETER)]. The comparison is carried out over the five seasonal prediction systems (SPSs) that participated in both projects. Since DEMETER, the contributing SPSs have improved in all aspects with the main advancements including the increase in resolution, the better representation of subgrid physical processes, land, sea ice, and greenhouse gas boundary forcing, and the more widespread use of assimilation for ocean initialization.

The ENSEMBLES results show an overall enhancement for the prediction of anomalous surface temperature conditions. However, the improvement is quite small and with considerable space–time variations. In the tropics, ENSEMBLES systematically improves the sharpness and the discrimination attributes of the forecasts. Enhancements of the ENSEMBLES resolution attribute are also reported in the tropics for the forecasts started 1 February, 1 May, and 1 November. Our results indicate that, in ENSEMBLES, an increased portion of prediction signal from the single-models effectively contributes to amplify the multimodel forecasts skill. On the other hand, a worsening is shown for the multimodel calibration over the tropics compared to DEMETER.

Significant changes are also shown in northern midlatitudes, where the ENSEMBLES multimodel discrimination, resolution, and reliability improve for February, May, and November starting dates. However, the ENSEMBLES multimodel decreases the capability to amplify the performance with respect to the contributing single models for the forecasts started in February, May, and August. This is at least partly due to the reduced overconfidence of the ENSEMBLES single models with respect to the DEMETER counterparts.

Provided that they are suitably calibrated beforehand, it is shown that the ENSEMBLES multimodel forecasts represent a step forward for the potential economical value they can supply. A warning for all potential users concerns the need for calibration due to the degraded tropical reliability compared to DEMETER. In addition, the superiority of recalibrating the ENSEMBLES predictions through the discrimination information is shown.

Concerning the forecasts started in August, ENSEMBLES exhibits mixed results over both tropics and northern midlatitudes. In this case, the increased potential predictability compared to DEMETER appears to be balanced by the reduction in the independence of the SPSs contributing to ENSEMBLES. Consequently, for the August start dates no clear advantage of using one multimodel system instead of the other can be evidenced.
Surface Analysis near and within the Tipton, Kansas, Tornado on 29 May 2008
Authors: Lee Bruce D. , Finley Catherine A. , Samaras Timothy M.
Published: September 2010

Data collected by a mesonet within the near-tornado environment and in the Tipton tornado on 29 May 2008 provided a rare opportunity to analyze rear-flank downdraft (RFD) outflow properties closely bounding a tornado and to characterize parcel thermodynamics being ingested into a tornado from the rear-flank downdraft. Parcels moving into the tornado on its right flank had very small negative buoyancy and considerable potential buoyancy. Measurements within and very near the tornado showed similar buoyancy characteristics to the storm inflow. Analyzed surface divergence and videographic evidence indicated that the RFD outflow just to the right and wrapping in front of the tornado was supported by parcels moving out of a narrow downdraft bordering the right flank of the tornado. Surface flow field analysis showed that parcels moved out of the downdraft-associated divergence region and into the right side of, as well as in front of, the tornado. An internal RFD surge boundary was positioned roughly 0.5 km in front of the eastern edge of the analyzed divergence region and implied downdraft.

The broader RFD outflow thermodynamic characteristics were consistent with recent research with only small negative buoyancy and substantial potential buoyancy; however, convective inhibition was considerably higher than typically found in other tornadic cases. This latter characteristic was emblematic of the broader storm environment on this day. Parcels making up the RFD outflow originated from low-levels, consistent with recent findings for tornadic rear-flank downdrafts and in contrast to past historical indications for the rear-flank downdraft source region.
Interpolation of LES Cloud Surfaces for Use in Direct Calculations of Entrainment and Detrainment
Authors: Dawe Jordan T. , Austin Philip H.
Published: September 2010

Direct calculations of the entrainment and detrainment of air into and out of clouds require knowledge of the relative velocity difference between the air and the cloud surface. However, a discrete numerical model grid forces the distance moved by a cloud surface over a time step to be either zero or the width of a model grid cell. Here a method for the subgrid interpolation of a cloud surface on a discrete numerical model grid is presented. This method is used to calculate entrainment and detrainment rates for a large-eddy simulation (LES) model, which are compared with rates calculated via the direct flux method of Romps. The comparison shows good agreement between the two methods as long as the model clouds are well resolved by the model grid spacing. This limitation of this technique is offset by the ability to resolve fluxes on much finer temporal and spatial scales, making it suitable for calculating entrainment and detrainment profiles for individual clouds.
Investigation of Microphysical Processes Occurring in Isolated Convection during NAME
Authors: Rowe Angela K. , Rutledge Steven A. , Lang Timothy J.
Published: September 2010

To address questions regarding microphysical processes occurring in the core North American monsoon region, data from NCAR’s S-band polarimetric Doppler radar (S-Pol) deployed during the North American Monsoon Experiment (NAME) in the summer of 2004, were used to investigate the location, size, and type of hydrometeors in convection. A cell identification and tracking algorithm was applied to this data over 100 h of microphysical scans, characterized by increased temporal and vertical resolution, to locate and track individual convective elements. Only isolated cells over land were included for this study to investigate potential elevation-dependent trends in microphysical processes in this region.

Examples of intense, isolated convection over all elevations revealed deep cells and polarimetric signatures comparable to other studies of tropical and midlatitude convection. A case over the low terrain highlighted deep, isolated convection with precipitation-sized ice extending to 15 km. In addition, the presence of differential reflectivity ZDR columns in these cells indicated the lofting of supercooled water above the melting level, and an enhanced linear depolarization ratio LDR “cap” above the column implied subsequent freezing to produce graupel. Similar features were also observed in an isolated cell over the western slopes, highlighting the combined roles of collision–coalescence and melting precipitation-sized ice for producing intense rainfall over the lower elevations. Despite previous observations of weaker and shallower cells with less precipitation ice over the Sierra Madre Occidental (SMO), case studies and general statistics using polarimetric data reveal the potential for accretional processes to also play an important role in producing intense rainfall over these higher elevations. For these isolated SMO cells, reduced warm-cloud depths, increased ice mass observed just above the melting level, and a narrower distribution of drop sizes suggest a reduced role of warm-rain processes compared to intense cells over the lower terrain. A potential relationship between microphysical processes and degree of organization is also hypothesized and will be the focus of a future study.
Creating a Capable Bureaucracy With Loyalists: The Internal Dynamics of the South Korean Developmental State, 1948-1979
Authors: Ha Yong-Chool , Kang Myung-koo
Published: September 2010

This study explores why South Korea’s top leadership combined a merit-based principle with region-based particularistic elements in the recruitment and promotion of career bureaucrats of the Ministry of Commerce and Industry (MCI) during its industrial takeoff in the 1960s and 1970s. It also investigates how this recruitment and promotion style was emulated by business sectors as a way of securing means to penetrate into the MCI. The authors argue that (a) South Korea’s top leadership utilized region-based particularistic elements to secure loyalty to the authoritarian leader and (b) state bureaucrats fell back on the readily available social resources of the time—informal social ties—to reduce the uncertainty innate to policy implementation and to achieve short-term policy goals, and this practice bred the organizational foundation that might undermine the bureaucratic character of the state—legalism and impersonalism—at the later stage of economic development.
The Nature, Determinants, and Consequences of Chávez’s Charisma: Evidence From a Study of Venezuelan Public Opinion
Authors: Merolla Jennifer L. , Zechmeister Elizabeth J.
Published: September 2010

Venezuelan President Hugo Chávez is frequently labeled “charismatic,” but this aspect of his leadership has mostly escaped direct argument and analysis. The authors offer a measure of charisma and a reciprocal account of the relationship between charisma and performance evaluations. Data from a national survey of Venezuelans confirm that perceptions of Chávez’s charisma in 2007 were comparatively high. Using three-stage least squares regression analysis the authors then document a highly dynamic process, by which poor performance erodes perceptions of Chávez’s charisma (and favors an opponent) while lingering beliefs in that charisma lead some to see better conditions than are perceived by those who do not subscribe to the charismatic sheen. The argument and analysis sharpen understandings of the nature, determinants, and consequences of charisma. The authors suggest that and explain why public support for Chávez is likely to recede at a slow, protracted pace rather than be abruptly withdrawn.
Mergers, jobs, and wages in the United States telecommunications industry
Authors: Majumdar Sumit K , Moussawi Rabih , Yaylacicegi Ulku
Published: September 2010

This article evaluates the human capital consequences of several mergers of local exchange companies that took place between 1988 and 2001 in the telecommunications industry of the United States. Most firms in the sector underwent one merger event while other firms underwent two events. The levels of jobs and average wages in the firms are assessed after the merger events and analysis reveals that, while the first merger events experienced by firms led to growth in employment and compensation, second merger events, which included several mega-mergers of the late 1990s and early 2000s, have led to stagnation and decline in employment levels and to negative human capital outcomes with declines in wage levels.
Liminality and the practices of identity reconstruction
Authors: Beech Nic
Published: September 2010

The purpose of this article is to contribute a conceptualization of liminality, a state of in-between-ness and ambiguity, as it applies to identity reconstruction of people in organizations. Liminality is discussed in anthropological and organizational literatures and a composite understanding is developed here. This incorporates a dialogical perspective and defines liminal practices along with varying orientations of dialogue between the self and others. Application of this conceptualization is illustrated by analysis of two cases and a broader application of the concept to the identity work literature is discussed.
Personality and inter-role conflict and enrichment: Investigating the mediating role of support
Authors: Friede Westring Alyssa , Ryan Ann Marie
Published: September 2010

Although researchers have discussed the relationships between personality and inter-role conflict and enrichment, little research explores why these relationships exist. This study examines the role of perceptions of support as one such mechanism. We expect that individuals with more positive core self-evaluations will perceive greater levels of support, which will enable them to avoid inter-role conflict and take advantage of opportunities for inter-role enrichment. In the current study, the inter-role conflict and enrichment faced by student-parents managing the demands of school and their parenting responsibilities are examined. Student-parents with more positive core self-evaluations were found to perceive and seek out greater levels of support, which related to more effective management of multiple life roles. Based on our findings, we argue that future research should continue to investigate the mechanisms by which personality affects the management of multiple life roles. Suggestions as to how practitioners can utilize the findings from this study to help individuals more effectively manage the demands of multiple life roles are provided.
Knowledge and practice in multidisciplinary teams: Struggle, accommodation and privilege
Authors: Oborn Eivor , Dawson Sandra
Published: September 2010

The importance of translating knowledge across occupational boundaries is frequently identified as a means of generating innovation and improving performance. The creation of the multidisciplinary team is an institutional response to enable such translation and synergy, yet few studies examine the processes of knowledge generation and translation in such teams. This article offers a case study that analyses these processes in decisions about the diagnosis and treatment of patients. Polanyi’s concept of tacit integration is used to reveal how meaning is developed and manifest in team decisions and to examine how the discursive resources embedded in tacit knowledge shape clinical practice. We highlight the foundations and dynamics that privilege the knowledge of some team members to be reconstituted as multidisciplinary group practice. Privileged knowledge then becomes embedded in the practices of the group. We conclude that the creation of a multidisciplinary structure may support rather than challenge existing power hierarchies.
‘Being yourself ’ in the electronic sweatshop: New forms of normative control
Authors: Fleming Peter , Sturdy Andrew
Published: September 2010

This article extends research about high-commitment management practices in tightly controlled work environments typified by the call centre. One promising research avenue suggests that normative management systems in such contexts, involving ‘fun’ exercises and culture programmes, etc., are more about distracting employee attention away from other, more taxing controls. This article develops such an approach by exploring the specific nature and conditions of such distraction. An empirical study of a call centre in which employees were encouraged to ‘ just be themselves’ (in relation to lifestyle differences, sexuality, diverse identities, etc.) reveals how the distractions are partly informed by the dysfunctions of existing technical, bureaucratic and conventional cultural controls, all of which homogenize workers. Furthermore, the new regime not only serves to distract employees, but proves instrumental in capturing their sociality, energy and ‘authentic’ or ‘non-work’ personalities as emotional labour. At the same time, it gives rise to some contestation and less individualistic forms of authenticity. These outcomes have wider implications for our understanding of worker autonomy in and around hybrid control systems.
Criminal justice and New Labour: A personal valediction
Authors: Fullwood Cedric
Published: September 2010

This comment piece is based on the experience of a Chief Probation Officer, who became a Probation Board Chair, and who had been at the beginning of Youth Justice reforms as well as member of an Independent Inquiry into ‘Alternatives to Custody’ (Coulsfield, 2004) — all during the thirteen years of the Labour Government. Some of the personal factors effecting policy developments are described, followed by some achievements as well as what the author considers critical failures of the New Labour years. In conclusion, the author offers four pieces of advice for the next Administration.
People are not things: What New Labour has done to Probation
Authors: Burke Lol , Collett Steve
Published: September 2010

To many observers, Probation at the end of Labour’s third term was characterized by an enduring sense of uncertainty resulting from a prolonged period of unremitting change, burdened by bureaucracy and over-zealous micro-management by the centre and subsumed into a complex organizational framework dominated by prison-based personnel. The sense of betrayal and alienation felt by many within the service towards the Government was a far cry from the cautious optimism that had marked the election of a Labour Government in 1997, coming as it did after a period in which the service had seen the short lived promise to move centre stage (Patten, 1988) replaced by an openly hostile promotion of prison works which seemed to threaten its very existence. In this article we attempt to evaluate the changing relationship between Probation and New Labour, placing it within the context of the wider approaches to crime control adopted by the government in each of its three terms in office. Finally, we consider the legacy of the past 13 years and conclude that despite the negative impact on Probation of an unrelenting reductionist focus on managerialist and technical policy fixes, there may yet be some grounds for optimism.
Probation: ‘A deceptive substitute for real contact’?
Authors: Keeler Jon
Published: September 2010

In a critical and challenging personal reflection on recent developments in criminal justice, the author, a long-term prisoner, argues that the prisoner’s ‘voice’ has been subjugated with the dominance of risk- and control-based polices and practice, and accuses the probation service of being complicit in this process.
Could economics solve the prison crisis?
Authors: Fox Chris , Albertson Kevin
Published: September 2010

This article considers important developments over the last decade which have laid the foundations for a new approach to criminal justice policy; an approach in which economic analysis is central. These developments include aspects of the policy debate on sentencing; the government’s commitment to evidence-based policy; investment in the economics profession across government; and the rise of the Justice Reinvestment movement. While many of the opportunities presented for economic analysis of sentencing policy have not yet been exploited, there is reason to believe that they will be over the next few years. Various reasons are discussed including the current economic situation, which makes increasingly untenable the continuing commitment of government to increasing prison capacity without consideration of more efficient alternatives. The article concludes by suggesting some steps that the new government might take to ensure that the benefits of an economically efficient approach to criminal justice policy are realized.
Review article: Shallow draughts: Larsen-Freeman and Cameron on complexity
Authors: Gregg Kevin R.
Published: September 2010

Complexity theory is a field of physics that studies the nature and behavior of complex systems, systems whose elements interact in complex and unpredictable ways. Recent years have seen a number of attempts to extend its scope to the biological and social sciences, and now Larsen-Freeman and Cameron offer a view of applied linguistics from a complexity perspective, claiming to show the relevance of the theory to various aspects of the language sciences. In this review of their book I look at their claims, and point out some of the reasons why these claims do not hold.
Effects of reading span and plausibility in the reanalysis of wh-gaps by Chinese-English second language speakers
Authors: Dussias Paola E. , Piñar Pilar
Published: September 2010

This study utilizes a moving window technique to investigate how individual cognitive resources (operationalized in terms of reading span scores) might modulate the extent to which native English speakers and Chinese second language (L2) learners of English utilize plausibility information to recover from an initial misparse in the processing of long-distance wh-questions. Consistent with findings in the previous literature, both groups postulated a filler-gap dependency at the earliest possible position. This was evidenced by subject—object extraction parsing asymmetries that were indicative of an initially incorrect filler-gap analysis. Additionally, it was found that plausibility did not prevent initial misparses, but affected how fast participants recovered from misanalysis, with implausible analyses facilitating recovery. However, only the English L2 participants in the higher span group resembled English native readers in their ability to exploit plausibility information in this way. We conclude that the individual cognitive resources of the learner are an important factor in determining the extent to which sentence processing might be qualitatively similar or different in a first language (L1) and a second language.
The perfective past tense in Greek as a second language
Authors: Clahsen Harald , Martzoukou Maria , Stavrakaki Stavroula
Published: September 2010

This study reports results from four experiments investigating the perfective past tense of Greek in adult second language (L2) learners. The data come from L2 learners of Greek with intermediate to advanced L2 proficiency and different native language (L1) backgrounds, and L1 speakers of Greek. All participants were tested in both oral and written elicited production and acceptability judgment tasks on both existing and novel verb stimuli. The results showed that the L2 learners did not achieve native-like performance on the perfective past tense in Greek, even at an advanced level of proficiency. The L2 learners often chose verb forms that did not encode the perfective past tense. Differences to native speakers were found particularly for non-sigmatic verb forms, which contain morphological irregularities in the target language. The results of the four experiments will be discussed in the light of previous findings and accounts of inflectional morphology in adult L2 learners. Taken together, the results suggest that L2 learners rely more on stored inflected word forms and on associative generalizations than native speakers.
Ultimate attainment of second language articles: A case study of an endstate second language Turkish-English speaker
Authors: Snape Neal , Kupisch Tanja
Published: September 2010

An area of considerable interest in second language (L2) acquisition is the difficulties learners face with the acquisition of articles. This article examines the role of prosody in the acquisition of articles by an endstate L2 English speaker focusing on the free morphemes the and a. In order to analyse the articles produced by a Turkish speaker named SD, we used the Praat (Boersma and Weenink, 2006) phonetic analysis software to determine the prosodic shape of each article in article + noun configurations and article + adjective + noun configurations. The aim of the analysis is to see whether a more detailed analysis of the data would be fully consistent with the strong or weak interpretation of the Prosodic Transfer Hypothesis. The findings of our analysis show that SD produces a large percentage of stressed articles, which are non target-like. We discuss the implications of our analysis for the interlanguage representation of articles by SD as well as the Prosodic Transfer Hypothesis.
Out With the Old, In With the New: Factor Analyses of a Classroom Environment Measure
Authors: Boren Rachel , Callahan Carolyn , Peugh James
Published: September 2010

Several instruments have been developed to gauge student perceptions of their classroom environment as greater attention has been given to the relationship between student achievement and student perceptions. One widely used instrument to assess those perceptions is the Classroom Environment Scale (CES), a 90-item measure for secondary level students that captures several dimensions of the classroom environment. However, psychometric analyses of this instrument are old and limited in conclusions. In order to update and reexamine the psychometric properties of the instrument, a sample of 1,207 middle school students were administered the CES. In a confirmatory factor analysis to test the model the instrument creators posited, model fit was poor. Subsequent exploratory and new confirmatory factor analyses were performed that produced more defensible results. The current study posits a new structure and model for the instrument with implications for potential users.