bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrin Signaling in Oligodendrocytes and Its Importance in CNS Myelination
Authors: O'Meara Ryan W. , Michalski John-Paul , Kothary Rashmi
Published: December 2010

Multiple sclerosis is characterized by repeated demyelinating attacks of the central nervous system (CNS) white matter tracts. To tailor novel therapeutics to halt or reverse disease process, we require a better understanding of oligodendrocyte biology and of the molecular mechanisms that initiate myelination. Cell extrinsic mechanisms regulate CNS myelination through the interaction of extracellular matrix proteins and their transmembrane receptors. The engagement of one such receptor family, the integrins, initiates intracellular signaling cascades that lead to changes in cell phenotype. Oligodendrocytes express a diverse array of integrins, and the expression of these receptors is developmentally regulated. Integrin-mediated signaling is crucial to the proliferation, survival, and maturation of oligodendrocytes through the activation of downstream signaling pathways involved in cytoskeletal remodeling. Here, we review the current understanding of this important signaling axis and its role in oligodendrocyte biology and ultimately in the myelination of axons within the CNS.
mBm‐Based Scalings of Traffic Propagated in Internet
Authors: Li Ming , Zhao Wei , Chen Shengyong
Published: December 2010

Scaling phenomena of the Internet traffic gain people′s interests, ranging from computer scientists to statisticians. There are two types of scales. One is small‐time scaling and the other large‐time one. Tools to separately describe them are desired in computer communications, such as performance analysis of network systems. Conventional tools, such as the standard fractional Brownian motion (fBm), or its increment process, or the standard multifractional fBm (mBm) indexed by the local Hölder functionH(t) may not be enough for this purpose. In this paper, we propose to describe the local scaling of traffic by usingD(t) on a point‐by‐point basis and to measure the large‐time scaling of traffic by using E[H(t)] on an interval‐by‐interval basis, where E implies the expectation operator. Since E[H(t)] is a constant within an observation interval whileD(t) is random in general, they are uncorrelated with each other. Thus, our proposed method can be used to separately characterize the small‐time scaling phenomenon and the large one of traffic, providing a new tool to investigate the scaling phenomena of traffic.
Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat
Authors: Wattanathorn Jintanaporn , Jittiwat Jinatta , Tongun Terdthai , Muchimapura Supaporn , Ingkaninan Kornkanok
Published: December 2010

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress‐related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH‐Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia.
Effects of Biosolids at Varying Rates on Earthworms (Eisenia fetida) and Springtails (Folsomia candida)
Authors: Artuso N. , Kennedy T. F. , Connery J. , Grant J. , Schmidt O.
Published: December 2010

Land spreading is a major option internationally for the disposal/use of treated sewage sludge (biosolids), but effects of this practice on soil organisms are largely unknown. This study investigated the effects of biosolids on two soil invertebrate species, earthworms (Eisenia fetida) and Collembola (Folsomia candida), in laboratory tests. Five biosolids from different sewage works were assessed at rates equivalent to 0, 2, 5, 10, and 20 t ha−1. Biosolids applied at 2 and 5 t ha−1did not cause mortality of adult earthworms but did at 10 and 20 t ha−1. At 5, 10 and 20 t ha−1, all biosolids had significantly fewer juvenile worms relative to controls. Increasing the rates from 2 to 10 t ha−1did not impact on the number of adult Collembola, but at 20 t ha−1there were significantly fewer adults. There were significantly fewer juvenile Collembola recorded for biosolids applied at the 2 t ha−1when compared with controls, and also when biosolids were applied at 5, 10, and 20 t ha−1relative to 2 t ha−1. Some significant difference between biosolids were observed, but generally, negative effects were not related to heavy metal concentrations in biosolids. It is recommended that possible detrimental mechanisms (e.g., ammonia production, lack of oxygen) be investigated in future work. It is concluded that biosolids, applied at legal, low rates (about 2 t ha−1) are unlikely to be detrimental to earthworms or adult Collembola but can be detrimental to Collembola reproduction.
Ventilation/Perfusion SPECT for Diagnosis of Pulmonary Embolism and Other Diseases
Authors: Bajc Marika , Jonson Björn
Published: December 2010

has the potential to become a first hand tool for diagnosis of pulmonary embolism based on standardized technology and new holistic interpretation criteria. Pretest
probability helps clinicians choose the most appropriate objective test for diagnosis or exclusion of PE. Interpretation should also take into account all ventilation and perfusion patterns allowing diagnosis of other cardiopulmonary diseases than PE. In such contexts, has excellent sensitivity and specificity. Nondiagnostic reports are ≤3%. has no contraindication; it is noninvasive and has very low radiation exposure. Moreover, acquisition time for is only 20 minutes. It allows quantification of PE extension which has an impact on individual treatment. It is uniquely useful for followup and research.
Role of Brush Biopsy and DNA Cytometry for Prevention, Diagnosis, Therapy, and Followup Care of Oral Cancer
Authors: Böcking Alfred , Sproll Christoph , Stöcklein Nikolas , Naujoks Christian , Depprich Rita , Kübler Norbert R. , Handschel Jörg
Published: December 2010

Late diagnosis resulting in late treatment and locoregional failure after surgery are the main causes of death in patients with oral squamous cell carcinomas (SCCs). Actually, exfoliative cytology is increasingly used for early detection of oral cancer and has been the subject of intense research over the last five years. Significant advances have been made both in relation to screening and evaluation of precursor lesions. As this noninvasive procedure is well tolerated by patients, more lesions may be screened and thus more oral cancers may be found in early, curable stages. Moreover, the additional use of DNA image cytometry is a reasonable tool for the assessment of the resection margins of SCC. DNA image cytometry could help to find the appropriate treatment option for the patients. Finally, diagnostic DNA image cytometry is an accurate method and has internationally been standardized. In conclusion, DNA image cytometry has increasing impact on the prevention, diagnostic, and therapeutical considerations in head and neck SCC.
ER Stress and Iron Homeostasis: A New Frontier for the UPR
Authors: Oliveira Susana J. , de Sousa Maria , Pinto Jorge P.
Published: December 2010

The C282Y mutation of HFE accounts for the majority of cases of the iron overload disease Hereditary Hemochromatosis (HH). The conformational changes introduced by this mutation impair the HFE association with β2-microglobulin (β2m) and the cell surface expression of the protein: with two major consequences. From a functional perspective, the ability of HFE to bind to transferrin receptors 1 and 2 is lost in the C282Y mutant, thus affecting hepcidin regulation. Also due to the faulty assembly with β2m, HFE-C282Y molecules remain in the endoplasmic reticulum (ER) as aggregates that undergo proteasomal degradation and activate an Unfolded Protein Response (UPR). UPR activation, regardless of the ER stress stimuli, was shown to reshape the expression profile of iron-related genes and to decrease MHC-I cell surface expression. The possibility of a HFE-C282Y-mediated interplay between the UPR and iron homeostasis influencing disease progression and the clinical heterogeneity among C282Y carriers is discussed. The responsiveness of the ER chaperone calreticulin to both ER and iron-induced oxidative stresses, and its correlation with HH patients’ phenotype, reinforce the interest of dissecting the UPR signaling/iron metabolism crosstalk and points to the potential clinical value of use of pharmacological chaperones in HFE-HH.
Spatial and Verbal rhetorics of power: Constructing late old kingdom history
Authors: Richards Janet
Published: December 2010

In writing ancient Egyptian social and political history, we take for granted that we should privilege neither textual nor material cultural evidence; rather, we should weave narratives incorporating both strands in weights commensurate with the actual profile of available data in a specific time and place. The mosaic of data available from the later Old Kingdom provides an especially compelling rationale for adopting this multidimensional approach. Earlier accounts of this pivotal era in ancient Egyptian history have relied most heavily on textual evidence ‐ not least because for the first time there existed lengthy biographical inscriptions of government officials providing tantalizing detail on individual political careers and legitimizing verbal rhetoric regarding possible historical events. In this particular period, however, the amounts of such textual data are outweighed in sheer quantity by contemporary archaeological remains. I have previously argued that spatial patterning, both in the synchronic distribution of these remains and (perhaps more compellingly) in the shifts of these patterns over time, should play an equal or even more prominent role in writing a socio-political history of this particular period. A primary case study explored in this essay is the late Old Kingdom mortuary landscape at Abydos where new data has emerged strengthening the diachronic evidence for the manipulation of a spatial rhetoric of political ideology, providing further insight into ancient Egyptian elites’ responses to perceived or real crises in centralized control of the country. This phenomenon at Abydos was only one part of a broader program of materializing central authority throughout the Egyptian Nile Valley at a time when the verbal rhetoric of royal power was limited in voice, audience, and context.
Equatorial Waves in Opposite QBO Phases
Authors: Yang Gui-Ying , Hoskins Brian J. , Slingo Julia M.
Published: December 2010

A methodology for identifying equatorial waves is used to analyze the multilevel 40-yr ECMWF Re-Analysis (ERA-40) data for two different years (1992 and 1993) to investigate the behavior of the equatorial waves under opposite phases of the quasi-biennial oscillation (QBO). A comprehensive view of 3D structures and of zonal and vertical propagation of equatorial Kelvin, westward-moving mixed Rossby–gravity (WMRG), and n = 1 Rossby (R1) waves in different QBO phases is presented. Consistent with expectation based on theory, upward-propagating Kelvin waves occur more frequently during the easterly QBO phase than during the westerly QBO phase. However, the westward-moving WMRG and R1 waves show the opposite behavior. The presence of vertically propagating equatorial waves in the stratosphere also depends on the upper tropospheric winds and tropospheric forcing.

Typical propagation parameters such as the zonal wavenumber, zonal phase speed, period, vertical wavelength, and vertical group velocity are found. In general, waves in the lower stratosphere have a smaller zonal wavenumber, shorter period, faster phase speed, and shorter vertical wavelength than those in the upper troposphere. All of the waves in the lower stratosphere show an upward group velocity and downward phase speed. When the phase of the QBO is not favorable for waves to propagate, their phase speed in the lower stratosphere is larger and their period is shorter than in the favorable phase, suggesting Doppler shifting by the ambient flow and a filtering of the slow waves. Tropospheric WMRG and R1 waves in the Western Hemisphere also show upward phase speed and downward group velocity, with an indication of their forcing from middle latitudes. Although the waves observed in the lower stratosphere are dominated by “free” waves, there is evidence of some connection with previous tropical convection in the favorable year for the Kelvin waves in the warm water hemisphere and WMRG and R1 waves in the Western Hemisphere, which is suggestive of the importance of convective forcing for the existence of propagating coupled Kelvin waves and midlatitude forcing for the existence of coupled WMRG and R1 waves.
The Static Stability of the Tropopause Region in Adiabatic Baroclinic Life Cycle Experiments
Authors: Erler Andre R. , Wirth Volkmar
Published: December 2010

The tropopause inversion layer (TIL) is a region of enhanced static stability just above the WMO-defined thermal tropopause. It is a ubiquitous feature in midlatitudes and is well characterized by observations. However, it is still lacking a satisfactory theoretical explanation.

This study utilizes adiabatic baroclinic life cycle experiments to investigate dynamical mechanisms that lead to TIL formation. As the baroclinic wave grows, a strong TIL forms above anticyclonic anomalies, while no TIL is found above cyclonic anomalies; this is consistent with previous results. However, during the early growth phase there is no TIL in the global or zonal average: positive and negative anomalies cancel out exactly. The zonal and global mean TIL only emerges during the mature stage of the life cycle, after the onset of wave breaking. The TIL predominantly occurs equatorward of the jet and the vertical structure bears resemblance to the TIL in midlatitudes; there is no equivalent to the subpolar TIL. Life cycles without significant wave breaking develop neither a global nor a zonal mean TIL. No global mean TIL is found in any life cycle if the dynamical tropopause definition is used.

In addition, a new mechanism of dynamical TIL formation is presented, suggesting that the TIL in the global and zonal mean is linked to a strongly skewed distribution of relative vorticity after wave breaking.
Improved Climate Simulation by MIROC5: Mean States, Variability, and Climate Sensitivity
Authors: Watanabe Masahiro , Suzuki Tatsuo , O’ishi Ryouta , Komuro Yoshiki , Watanabe Shingo , Emori Seita , Takemura Toshihiko , Chikira Minoru , Ogura Tomoo , Sekiguchi Miho , Takata Kumiko , Yamazaki Dai , Yokohata Tokuta , Nozawa Toru , Hasumi Hiroyasu , Tatebe Hiroaki , Kimoto Masahide
Published: December 2010

A new version of the atmosphere–ocean general circulation model cooperatively produced by the Japanese research community, known as the Model for Interdisciplinary Research on Climate (MIROC), has recently been developed. A century-long control experiment was performed using the new version (MIROC5) with the standard resolution of the T85 atmosphere and 1° ocean models. The climatological mean state and variability are then compared with observations and those in a previous version (MIROC3.2) with two different resolutions (medres, hires), coarser and finer than the resolution of MIROC5.

A few aspects of the mean fields in MIROC5 are similar to or slightly worse than MIROC3.2, but otherwise the climatological features are considerably better. In particular, improvements are found in precipitation, zonal mean atmospheric fields, equatorial ocean subsurface fields, and the simulation of El Niño–Southern Oscillation. The difference between MIROC5 and the previous model is larger than that between the two MIROC3.2 versions, indicating a greater effect of updating parameterization schemes on the model climate than increasing the model resolution. The mean cloud property obtained from the sophisticated prognostic schemes in MIROC5 shows good agreement with satellite measurements. MIROC5 reveals an equilibrium climate sensitivity of 2.6 K, which is lower than that in MIROC3.2 by 1 K. This is probably due to the negative feedback of low clouds to the increasing concentration of CO2, which is opposite to that in MIROC3.2.
Physical Mechanisms for the Maintenance of GCM-Simulated Madden–Julian Oscillation over the Indian Ocean and Pacific
Authors: Deng Liping , Wu Xiaoqing
Published: December 2010

The kinetic energy budget is conducted to analyze the physical processes responsible for the improved Madden–Julian oscillation (MJO) simulated by the Iowa State University general circulation models (ISUGCMs). The modified deep convection scheme that includes the revised convection closure, convection trigger condition, and convective momentum transport (CMT) enhances the equatorial (10°S–10°N) MJO-related perturbation kinetic energy (PKE) in the upper troposphere and leads to a more robust and coherent eastward-propagating MJO signal. In the MJO source region, the Indian Ocean (45°–120°E), the upper-tropospheric MJO PKE is maintained by the vertical convergence of wave energy flux and the barotropic conversion through the horizontal shear of mean flow. In the convectively active region, the western Pacific (120°E–180°), the upper-tropospheric MJO PKE is supported by the convergence of horizontal and vertical wave energy fluxes. Over the central-eastern Pacific (180°–120°W), where convection is suppressed, the upper-tropospheric MJO PKE is mainly due to the horizontal convergence of wave energy flux. The deep convection trigger condition produces stronger convective heating that enhances the perturbation available potential energy (PAPE) production and the upward wave energy fluxes and leads to the increased MJO PKE over the Indian Ocean and western Pacific. The trigger condition also enhances the MJO PKE over the central-eastern Pacific through the increased convergence of meridional wave energy flux from the subtropical latitudes of both hemispheres. The revised convection closure affects the response of mean zonal wind shear to the convective heating over the Indian Ocean and leads to the enhanced upper-tropospheric MJO PKE through the barotropic conversion. The stronger eastward wave energy flux due to the increase of convective heating over the Indian Ocean and western Pacific by the revised closure is favorable to the eastward propagation of MJO and the convergence of horizontal wave energy flux over the central-eastern Pacific. The convection-induced momentum tendency tends to decelerate the upper-tropospheric wind, which results in a negative work to the PKE budget in the upper troposphere. However, the convection momentum tendency accelerates the westerly wind below 800 hPa over the western Pacific, which is partially responsible for the improved MJO simulation.
Modeling of Regional Hydroclimate Change over the Indian Subcontinent: Impact of the Expanding Thar Desert
Authors: Bollasina Massimo , Nigam Sumant
Published: December 2010

The Thar Desert between northwestern India and Pakistan is the most densely populated desert region in the world, and the vast surrounding areas are affected by rapid soil degradation and vegetation loss. The impact of an expanded desert (implemented by changing vegetation type and related greenness fraction, albedo, surface roughness length, emissivity, among others) on the South Asian summer monsoon hydroclimate is investigated by means of 7-month, 4-member ensemble sensitivity experiments with the Weather Research and Forecasting model.

It is found that extended desertification significantly affects the monsoon at local and large scales. Locally, the atmospheric water cycle weakens because precipitation, evaporation, and atmospheric moisture convergence all decrease; soil moisture and runoff reduce too. Air temperature cools because of an increase in albedo (the desert makes the area brighter) and a reduction of surface turbulent fluxes; the cooling is partially offset by adiabatic descent, generated to maintain thermodynamic balance and originating at the northern flank of the low-level anticyclone forced by desert subsidence. Regionally, an anomalous northwesterly flow over the Indo-Gangetic Plain weakens the monsoon circulation over northeastern India, causing precipitation to decrease and the formation of an anomalous anticyclone in the region. As a result, the middle troposphere cools because of a decrease in latent heat release, but the ground heats up because of a reduction in cloudiness. At larger scale, the interaction between the anomalous circulation and the mountains leads to an increase in precipitation over the eastern Himalayas and Indochina.

The findings of this study reveal that the expansion of the Thar Desert can lead to a pronounced and large-scale impact on summer monsoon hydroclimate, with a potential to redistribute precious water over South Asia.
Subduction and Transport in the Indian and Pacific Oceans in a 2 × CO2 Climate
Authors: Saenko Oleg A. , Yang Xiao-Yi , England Matthew H. , Lee Warren G.
Published: December 2010

Subduction, water mass transformation, and transport rates in the Indo-Pacific Ocean are diagnosed in a recent version of the Canadian Centre for Climate Modelling and Analysis coupled model. It is found that the subduction across the base of the winter mixed layer is dominated by the lateral transfer, particularly within the relatively dense water classes corresponding to the densest mode and intermediate waters. However, within lighter densities, including those characterizing the lighter varieties of mode waters, the vertical transfer has a strong positive input to the net subduction. The upper-ocean volume transports across 30°N and 32°S are largest within the density classes that correspond to mode waters. In the North Pacific, the buoyancy flux converts the near-surface waters mostly to denser water classes, whereas in the Southern Ocean the surface waters are transformed both to lighter and denser water classes, depending on the density. In response to a doubling of CO2, the subduction, transformation, and transport of mode waters in both hemispheres shift to lighter densities but do not change significantly, whereas the subduction of intermediate waters decreases. The area of large winter mixed layer depths decreases, particularly in the Southern Hemisphere. In the low latitudes, the thermocline water flux that enters the tropical Pacific via the western boundary flows generally increases. However, its anomaly has a complex structure, so that integrated estimates can be sensitive to the isopycnal ranges. The upper part of the Equatorial Undercurrent (EUC) strengthens in the warmer climate, whereas its lower part weakens. The anomaly in the EUC closely follows the anomaly in stratification along the equator. The Indonesian Throughflow transport decreases with part of it being redirected eastward. This part joins with the intensified equatorward thermocline flows at the western boundaries and contributes to the EUC anomaly.
Effects of Deforestation on Spatiotemporal Distributions of Precipitation in South America
Authors: Medvigy David , Walko Robert L. , Avissar Roni
Published: December 2010

This study investigates how future deforestation in the Amazon may alter precipitation statistics in South America using a variable-resolution GCM. The model’s grid mesh is set up to cover South America and nearby oceans at mesoscale (25 km) resolution, and then to gradually coarsen and cover the rest of the world at 200-km resolution. Because of the computational efficiency of this approach, it was possible to carry out the first decadal-scale simulations of Amazon deforestation at mesoscale resolution. Unlike traditional mesoscale models, this approach does not require lateral boundary conditions. The results indicate that deforestation reduces simulated precipitation in the Amazon, but this reduction is much smaller than that seen in most previous GCM studies. Furthermore, a subcontinental redistribution of precipitation is found whereby the northwest Amazon becomes drier and the southeast Amazon becomes wetter. During most of the year, these changes are driven by changes in the mean intensity of precipitation events; however, in September–November, changes in precipitation frequency are also important. Large changes in June–August hydroclimate were also found, with extreme cold events becoming more common. These changes have consequences for agriculture, natural ecosystems, and surface hydrology.
The Atmospheric Response to Projected Terrestrial Snow Changes in the Late Twenty-First Century
Authors: Alexander Michael A. , Tomas Robert , Deser Clara , Lawrence David M.
Published: December 2010

Two atmospheric general circulation model experiments are conducted with specified terrestrial snow conditions representative of 1980–99 and 2080–99. The snow states are obtained from twentieth-century and twenty-first-century coupled climate model integrations under increasing greenhouse gas concentrations. Sea surface temperatures, sea ice, and greenhouse gas concentrations are set to 1980–99 values in both atmospheric model experiments to isolate the effect of the snow changes. The reduction in snow cover in the twenty-first century relative to the twentieth century increases the solar radiation absorbed by the surface, and it enhances the upward longwave radiation and latent and sensible fluxes that warm the overlying atmosphere. The maximum twenty-first-century minus twentieth-century surface air temperature (SAT) differences are relatively small (<3°C) compared with those due to Arctic sea ice changes (∼10°C). However, they are continental in scale and are largest in fall and spring, when they make a significant contribution to the overall warming over Eurasia and North America in the twenty-first century. The circulation response to the snow changes, while of modest amplitude, involves multiple components, including a local low-level trough, remote Rossby wave trains, an annular pattern that is strongest in the stratosphere, and a hemispheric increase in geopotential height.
Canadian RCM Projected Changes to Extreme Precipitation Characteristics over Canada
Authors: Mladjic B. , Sushama L. , Khaliq M. N. , Laprise R. , Caya D. , Roy R.
Published: December 2010

Changes to the intensity and frequency of hydroclimatic extremes can have significant impacts on sectors associated with water resources, and therefore it is relevant to assess their vulnerabilities in a changing climate. This study focuses on the assessment of projected changes to selected return levels of 1-, 2-, 3-, 5-, 7- and 10-day annual (April–September) maximum precipitation amounts, over Canada, using an ensemble of five 30-yr integrations each for current reference (1961–90) and future (2040–71) periods performed with the Canadian Regional Climate Model (CRCM); the future simulations correspond to the A2 Special Report on Emissions Scenarios (SRES) scenario. Two methods, the regional frequency analysis (RFA), which operates at the scale of statistically homogenous units of predefined climatic regions, with the possibility of downscaling to gridcell level, and the individual gridbox analysis (GBA), are used in this study, with the time-slice stationarity assumption. Validation of model simulated 20-, 50- and 100-yr return levels of single- and multiday precipitation extremes against those observed for the 1961–90 period using both the RFA and GBA methods suggest an underestimation of extreme events by the CRCM over most of Canada. The CRCM projected changes, realized with the RFA method at regional scale, to selected return levels for the future (2041–70) period, in comparison to the reference (1961–90) period, suggest statistically significant increases in event magnitudes for 7 out of 10 studied climatic regions. Though the results of the RFA and GBA methods at gridcell level suggest positive changes to studied return levels for most parts of Canada, the results corresponding to the 20-yr return period for the two methods agree better, while the agreement abates with increasing return periods, that is, 50 and 100 yr. It is expected that the increase in return levels of short and longer duration precipitation extremes will have severe implications for various water resource–related development and management activities.
A Diagnostic Comparison of Alaskan and Siberian Strong Anticyclones
Authors: Jones Justin E. , Cohen Judah
Published: December 2010

Strong anticyclones have a significant impact on the cool season climate over mid- and high-latitude landmasses as they are typically accompanied by arctic air masses that can eventually move into populated midlatitude regions. Composite analyses of Alaskan and Siberian strong anticyclones based on sea level pressure (SLP) thresholds of 1050 and 1060 hPa, respectively, were performed to diagnose large-scale dynamical and thermodynamical parameters associated with the formation of strong anticyclones over these two climatologically favorable regions. The anticyclone composite analyses indicate the presence of moderate-to-high-amplitude ridge–trough patterns associated with anticyclogenesis. These ridge–trough patterns are critical as they lead to dynamically favorable circumstances for rapid anticyclogenesis.

The strong Alaskan anticyclone develops downstream of a highly amplified upper-tropospheric ridge and is associated with a region of strong tropospheric subsidence due to differential anticyclonic vorticity advection and cold-air advection over the anticyclone center. The strong Siberian anticyclone is associated with an upper-tropospheric pattern of lesser amplitude, suggesting that these dynamical factors, while still important, are less critical to its development. The relative location of elevated terrain features also appears to contribute greatly to the overall evolution of each of these anticyclones.
The Effect of Explosive Tropical Volcanism on ENSO
Authors: McGregor Shayne , Timmermann Axel
Published: December 2010

This study examines the response of El Niño–Southern Oscillation (ENSO) to massive volcanic eruptions in a suite of coupled general circulation model (CGCM) simulations utilizing the Community Climate System Model, version 3 (CCSM3). The authors find that the radiative forcing due to volcanic aerosols injected into the stratosphere induces a model climatic response that projects onto the ENSO mode and initially creates a La Niña event that peaks around the time the volcanic forcing peaks. The curl of the wind stress changes accompanying this volcanically forced equatorial region cooling acts to recharge the equatorial region heat. For weaker volcanic eruptions, this recharging results in an El Niño event about two seasons after the peak of the volcanic forcing. The results of the CCSM3 volcanic forcing experiments lead the authors to propose that the initial tropical Pacific Ocean response to volcanic forcing is determined by four different mechanisms—one process is the dynamical thermostat mechanism (the mean upwelling of anomalous temperature) and the other processes are related to the zonal equatorial gradients of the mean cloud albedo, Newtonian cooling, and mixed layer depth. The zonal gradient in CCSM3 set by both mixed layer depth and Newtonian cooling terms oppose the zonal sea surface temperature anomaly (SSTA) gradient produced by the dynamical thermostat and initially dominate the mixed layer zonal equatorial heat budget response. Applying this knowledge to a simple volcanically forced mixed layer equation using observed estimates of the spatially varying variables, the authors again find that the mixed layer depth and Newtonian cooling terms oppose and dominate the zonal SSTA gradient produced by the dynamical thermostat. This implies that the observed initial response to volcanic forcing should be La Niña–like not El Niño, as suggested by paleoclimate records.
A Synoptic Climatology of Episodic, Subseasonal Retractions of the Pacific Jet
Authors: Jaffe Sharon C. , Martin Jonathan E. , Vimont Daniel J. , Lorenz David J.
Published: December 2010

Twenty-eight years of NCEP–NCAR reanalysis data are employed in a composite analysis of the structure and evolution of the large-scale circulation associated with rapid, subseasonal, westward retractions of the Northern Hemisphere Pacific jet. Nineteen Pacific jet retractions are identified in the dataset. The salient characteristics of these transitions are presented, emphasizing the structure and evolution of anomalies in the zonal wind, upper-tropospheric geopotential height, sea level pressure (SLP), and tropopause potential vorticity (PV). The composite analysis demonstrates that as the jet retracts, a transition from a dominant negative anomaly to a dominant positive anomaly across the North Pacific in both the 500-hPa geopotential height and SLP fields occurs in ~10 days. The resulting anticyclonic anomalies are sprawling and intense with SLP anomalies of nearly 20 hPa and 500-hPa geopotential height anomalies of more than 200 m. The vertical superposition of these upper- and lower-level anomalies indicates that these composite structures are equivalent barotropic. These results are also consistent with the composite 200–250-hPa Ertel PV anomaly field, in which a jet retraction event is characterized by the formation of a zonally elongated, meridionally oriented PV anomaly couplet in the central North Pacific that becomes increasingly isotropic in the jet exit region simultaneous with the retraction of the jet. Because of the large spatial scale of these events, the results are also discussed in the context of storm-track variability, the East Asian winter monsoon, and tropical diabatic heating anomalies.
Continuous, Array-Based Estimates of Atlantic Ocean Heat Transport at 26.5°N
Authors: Johns W. E. , Baringer M. O. , Beal L. M. , Cunningham S. A. , Kanzow T. , Bryden H. L. , Hirschi J. J. M. , Marotzke J. , Meinen C. S. , Shaw B. , Curry R.
Published: December 2010

Continuous estimates of the oceanic meridional heat transport in the Atlantic are derived from the Rapid Climate Change–Meridional Overturning Circulation (MOC) and Heatflux Array (RAPID–MOCHA) observing system deployed along 26.5°N, for the period from April 2004 to October 2007. The basinwide meridional heat transport (MHT) is derived by combining temperature transports (relative to a common reference) from 1) the Gulf Stream in the Straits of Florida; 2) the western boundary region offshore of Abaco, Bahamas; 3) the Ekman layer [derived from Quick Scatterometer (QuikSCAT) wind stresses]; and 4) the interior ocean monitored by “endpoint” dynamic height moorings. The interior eddy heat transport arising from spatial covariance of the velocity and temperature fields is estimated independently from repeat hydrographic and expendable bathythermograph (XBT) sections and can also be approximated by the array.

The results for the 3.5 yr of data thus far available show a mean MHT of 1.33 ± 0.40 PW for 10-day-averaged estimates, on which time scale a basinwide mass balance can be reasonably assumed. The associated MOC strength and variability is 18.5 ± 4.9 Sv (1 Sv ≡ 106 m3 s−1). The continuous heat transport estimates range from a minimum of 0.2 to a maximum of 2.5 PW, with approximately half of the variance caused by Ekman transport changes and half caused by changes in the geostrophic circulation. The data suggest a seasonal cycle of the MHT with a maximum in summer (July–September) and minimum in late winter (March–April), with an annual range of 0.6 PW. A breakdown of the MHT into “overturning” and “gyre” components shows that the overturning component carries 88% of the total heat transport. The overall uncertainty of the annual mean MHT for the 3.5-yr record is 0.14 PW or about 10% of the mean value.
Tropospheric Rossby Wave Breaking and the SAM
Authors: Wang Yi-Hui , Magnusdottir Gudrun
Published: December 2010

An objective analysis of tropospheric anticyclonic- and cyclonic-breaking Rossby waves is performed for the Southern Hemisphere in austral summer (December–February) of 1979–2009. The climatology of both anticyclonic and cyclonic Rossby wave breaking (RWB) frequency is presented. The frequency of anticyclonic RWB is highest in an extended region of the Eastern Hemisphere on the anticyclonic side of the jet, while that of cyclonic RWB is highest on the cyclonic side of the jet. A composite analysis of anticyclonic and cyclonic RWB shows how they contribute to a positive and negative southern annual mode (SAM) index, respectively. The time series of austral summer anticyclonic RWB occurrence has a trend that closely matches the trend in the SAM index.

Regions of RWB that are significantly correlated with the SAM index are objectively determined. Even though several such regions are identified, only two regions (anticyclonic and cyclonic) covering 17% of the area of the hemisphere are required in a linear regression model of the SAM index. The anticyclonic RWB region is zonally extended at 45°S and explains 78% of the variability of the summer-mean SAM index. The cyclonic region is located at high latitudes somewhat decoupled from the jet, in the longitudinal sector of the Indian Ocean. On synoptic time scales, transitions of the SAM index respond to RWB without time lag.

ENSO cycles present an interesting zonal asymmetry to the distribution of Southern Hemispheric RWB in the central Pacific. Anticyclonic RWB is increased in the tropical/subtropical central Pacific during La Niña compared to El Niño. This increase is related to the strong local decrease in zonal wind. At the same time, anticyclonic RWB outside the central Pacific is increased in frequency poleward and decreased in frequency equatorward of 42°S, corresponding to a positive SAM index.
Predictability of Heavy Precipitation in the Waikato River Basin of New Zealand
Authors: Dravitzki Stacey , McGregor James
Published: December 2010

This paper investigates the predictability of heavy precipitation in the economically important Waikato River basin of New Zealand. A 2-yr archive of Global Forecast System (GFS) model data to +180 h for the period August 2005–August 2007 forms the basis of the study. GFS model predictions of precipitation are compared to surface measurements from 22 stations in and around the river basin. Categorical hit rate and bias, threat score, false-alarm ratio, probability of detection, RMSE, skill score, and mean error are all plotted as a function of model lead time for the 2-yr period.

The general synoptic structures of heavy precipitation events are often identified at long lead times. An example is shown for January 2006 when heavy rainfall is identified by GFS at +150 h, accurate location and timing is given at +48 h. Precipitation amounts are systematically underpredicted by GFS and the spatial distribution of rainfall is limited by model resolution. The value of GFS lies in its ability to provide early warning of potential heavy precipitation.

Three heavy rainfall events were selected for higher-resolution Weather Research and Forecasting (WRF) model simulation. The WRF model produced more realistic geographical distributions of precipitation but cannot compensate for errors in the global model. WRF underpredicts precipitation for all three cases; the best simulation generates 92% of observed precipitation.

Unobserved spurious convective rainfall can be generated by the WRF model following the passage of a frontal weather system. A possible mechanism is suggested that links this to underpredicted frontal rainfall.
Race, Culture, and the Anglo-American Powers: The Views of Chinese Collaborators
Authors: Wai Chor So
Published: December 2010

This article examines the views of Chinese collaborators on Pan-Asianism, race, and culture during 1939—1945. It depicts the changing attitudes of Chinese collaborators toward the Anglo-American nations, and discusses how the Pacific War led to the revival of the concept of Pan-Asianism and the appearance of a racial and cultural discourse among Chinese collaborators. Also, it analyzes the nature of collaborators’ discourse on race and culture. This is an uncommon episode in twentieth-century Chinese history in which Chinese propaganda gave vent to racial sentiments.
Why school psychology for diversity?
Authors: Bartolo Paul A.
Published: December 2010

This article discusses the dilemma faced by psychologists in responding to diversity. It is based on a qualitative review of relevant literature over the past decade. It first describes psychologists as frontrunners in recognizing the uniqueness and autonomy of each of their diverse clients but within the biomedical model that locates problems within clients. This raises a dilemma vis-à-vis diversity issues which are associated with discrimination suffered by minority groups who are best supported by changes in social structures and processes. An account is then given of an increasing adoption of a biopsychosocial model, with further influence of the social model of disability and mental health. Evidence of the trend is explored in a new commitment to the human rights agenda, changes in ethical codes, and in psychologists’ engagement with intervention at macro systems levels as in the promotion of inclusive education. The review concludes with the implications of these trends for greater changes in training institutions to reflect openness to diversity, and in training programmes to promote an understanding of, and skills in, using social approaches to addressing the needs of clients who are at risk of being misunderstood, devalued, and discriminated against.
School psychology: Learning lessons from history and moving forward
Authors: Farrell Peter
Published: December 2010

At a time when, in most countries, the profession of school psychology is experiencing a period of growth and expansion, many problems still remain. The origins of these problems are linked to the historical development of the profession which has provided school psychologists with a unique and distinctive role in administering IQ tests and using the results to make decisions about special educational provision for children with learning difficulties. This article reviews recent research that is heavily critical of the relevance of IQ testing and the associated medical model of working, and then considers some of the barriers which prevent school psychologists from changing their practices. It concludes with suggestions as to how the profession can move forward with confidence, knowing that it can make a distinctive contribution to supporting vulnerable children, schools and communities around the world.
The role of the school psychologist in inclusive education for ensuring quality learning outcomes for all learners
Authors: Forlin Chris
Published: December 2010

In comparison to international perspectives, the specific role of the school psychologist in Hong Kong will provide a case study of the tensions experienced by a system in transition between a very traditional, highly segregated education system, to one that is actively promoting a whole school approach to inclusion. Consideration will initially be given to the development of inclusive education and the identification of quality learning outcomes for students. The role of the school psychologists in Hong Kong and the challenges they face will be compared to other international jurisdictions, focusing on both internal and external influences that have impacted on their role in recent years.
Developing inclusive policy and practice in diverse contexts: A South African experience
Authors: Daniels Berenice
Published: December 2010

Pre-1994, South Africa was a country riddled with inequality and discrimination stemming from the policy of ‘apartheid’. Since 1994, there have been considerable efforts made to enable the country to move toward becoming non-racial and democratic, with a culture of human rights and social justice. One of the primary tasks of the new democratically elected government was a reform of the education system. Specialized Education was initially neglected, but then in 1996 a National Commission was appointed to investigate Special Needs in Education and Education Support Services, of which the author was one of the co-ordinators. The timeline for the full implementation of the resulting White Paper 6 on Inclusive Education is 20 years. Inclusive Education in South Africa aims to meet the needs of all learners by addressing barriers to learning, welcoming diversity and fostering maximum participation by all in the culture of the school. This article, based on the author’s experience, will discuss the challenges for implementation of the policy in one of the South African districts which field-tested the recommendations in White Paper 6, a district with diverse contexts, the emerging promising practice, and the implications for specialized support professionals, in particular the role of school psychologists.
Signaling Theory: A Review and Assessment
Authors: Connelly Brian L. , Certo S. Trevis , Ireland R. Duane , Reutzel Christopher R.
Published: December 2010

Signaling theory is useful for describing behavior when two parties (individuals or organizations) have access to different information. Typically, one party, the sender, must choose whether and how to communicate (or signal) that information, and the other party, the receiver, must choose how to interpret the signal. Accordingly, signaling theory holds a prominent position in a variety of management literatures, including strategic management, entrepreneurship, and human resource management. While the use of signaling theory has gained momentum in recent years, its central tenets have become blurred as it has been applied to organizational concerns. The authors, therefore, provide a concise synthesis of the theory and its key concepts, review its use in the management literature, and put forward directions for future research that will encourage scholars to use signaling theory in new ways and to develop more complex formulations and nuanced variations of the theory.
Promoting Human Dignity: An evaluation of a programme for racially motivated offenders
Authors: Palmer Julia , Smith David
Published: December 2010

This article gives an account of an evaluation of a programme for racially motivated offenders designed and run by probation staff in Merseyside. Originally a response to the 1998 Crime and Disorder Act, the programme was adapted in response to changed patterns of migration and racist hostility. A groupwork version of the programme was started in 2008, and this became a particular focus of the evaluation. Offenders who participated in both individual and group versions generally reported positive learning experiences, and appreciated the style and knowledge of the facilitators. The article argues that the content and delivery of the programme are in line with what research suggests should be helpful practice with this group of offenders, and that the programme is a positive example of skilled, creative practice.