bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neurotoxicants, Micronutrients, and Social Environments
Authors: Hubbs-Tait Laura , Nation Jack R. , Krebs Nancy F. , Bellinger David C. 
Published: January 2006

SUMMARY—Systematic research evaluating the separate and interacting impacts of neurotoxicants, micronutrients, and social environments on children's cognition and behavior has only recently been initiated. Years of extensive human epidemiologic and animal experimental research document the deleterious impact of lead and other metals on the nervous system. However, discrepancies among human studies and between animal and human studies underscore the importance of variations in child nutrition as well as social and behavioral aspects of children's environments that mitigate or exacerbate the effects of neurotoxicants.In this monograph, we review existing research on the impact of neurotoxic metals, nutrients, and social environments and interactions across the three domains. We examine the literature on lead, mercury, manganese, and cadmium in terms of dispersal, epidemiology, experimental animal studies, effects of social environments, and effects of nutrition.Research documenting the negative impact of lead on cognition and behavior influenced reductions by the Center for Disease Control in child lead-screening guidelines from 30 micrograms per deciliter (μg/dL) in 1975 to 25 μg/dL in 1985 and to 10 μg/dL in 1991. A further reduction is currently being considered. Experimental animal research documents lead's alteration of glutamate-neurotransmitter (particularly N-methyl-D-aspartate) activity vital to learning and memory. In addition, lead induces changes in cholinergic and dopaminergic activity. Elevated lead concentrations in the blood are more common among children living in poverty and there is some evidence that socioeconomic status influences associations between lead and child outcomes. Micronutrients that influence the effects of lead include iron and zinc.Research documenting the negative impact of mercury on children (as well as adults) has resulted in a reference dose (RfD) of 0.1 microgram per kilogram of body weight per day (μg/kg/day). In animal studies, mercury interferes with glutamatergic, cholinergic, and dopaminergic activity. Although evidence for interactions of mercury with children's social contexts is minimal, researchers are examining interactions of mercury with several nutrients.Research on the effects of cadmium and manganese on child cognition and behavior is just beginning. Experimental animal research links cadmium to learning deficits, manganese to behaviors characteristic of Parkinson's disease, and both to altered dopaminergic functioning.We close our review with a discussion of policy implications, and we recommend interdisciplinary research that will enable us to bridge gaps within and across domains.
The Impact of Inflation Measures on the Real Returns and Risk of U.S. Stocks
Authors: Jones Charles P. , Wilson Jack W. 
Published: January 2006

AbstractUsing different inflation measures produces economically significant differences in both the inflation record and inflation‐adjusted stock returns. We introduce a more consistent measure of the monthly Consumer Price Index (CPI) inflation rate to better measure real returns over 1913–2004, for which the official CPI exists. We also extend the series backward to 1871 on a monthly basis, an important addition to the data series. We analyze the impact of inflation on the real standard deviation of stock returns and find that, in contrast to the results for geometric mean returns, inflation adjustments have little impact on estimates of return variability.
Portfolio Effects and Valuation of Weather Derivatives
Authors: Brockett Patrick L. , Wang Mulong , Yang Chuanhou , Zou Hong 
Published: January 2006

AbstractIn a mean‐variance framework, the indifference pricing approach is adopted to value weather derivatives, taking account of portfolio effects. Our analysis shows how the magnitude of portfolio effects is related to the correlation between weather indexes and other risky assets, the correlation between weather indexes, and the payoff structures of the existing weather derivatives in an investor's asset portfolio. We also conduct some preliminary empirical analysis. This study contributes to the weather derivative pricing literature by incorporating both the hedgeable and unhedgeable parts of weather risks in illustrating the portfolio effects on the indifference prices of weather derivatives.
Inferring Public and Private Information from Trades and Quotes
Authors: Frijns Bart 
Published: January 2006

AbstractWe propose a new model that uses nonsynchronous, ultra‐high frequency data to analyze the sequential impact of trades and quotes on the price process. Private information is related to the impact of trades and public information to the impact of quotes. The model is extended to include various other factors that affect public and private information. For 20 active Nasdaq stocks, private information causes, on average, 9.43% of daily stock price movements. Additionally, quotes are more informative when (1) many dealers set the best price and (2) traditional market makers rather than Electronic Communication Networks set the best price.
Price Movements, Information, and Liquidity in the Night Trading Market
Authors: Giannetti Antoine , Larson Stephen J. , Lee Chun I. , Madura Jeff 
Published: January 2006

Forward Links to Citing Articles

Erratum. The Financial Review 41: 2, 305. Online publication date: 11‐Apr‐2006. AbstractNight trading provides an ideal laboratory to assess the behavior of stock markets when institutional liquidity providers are less active. The evidence indicates that extreme positive (winner) and negative (loser) stock‐price movements during night sessions are followed by reversals the next day. The reversals are more pronounced following extreme stock‐price movements that are associated with less trading volume and lower liquidity. Within‐the‐night sample reversals are less pronounced for stocks of companies issuing earnings announcements.
THE RELATIONSHIP BETWEEN LABOUR MARKET DYNAMICS AND HIV/AIDS PREVALENCE IN SOUTH AFRICA ‐ A LITERATURE REVIEW1
Authors: VASS JOCELYN 
Published: January 2006

AbstractThe aim of this literature review is to analyse the contribution of current research and literature to an understanding of the relationship between labour market dynamics and HIV/AIDS prevalence in South Africa. It highlights and assesses the extent to which those factors that are regarded as determinants of HIV susceptibility, AIDS vulnerability and prevalence, interact with differentiation in the labour market. The conclusion is that current research studies do not sufficiently consider a more nuanced relationship between complex labour market dynamics and socio‐economic risk factors driving HIV/AIDS susceptibility and vulnerability.
POVERTY AND LABOUR MARKET MARKERS OF HIV POSITIVE HOUSEHOLDS IN SOUTH AFRICA: AN EXPLORATORY METHODOLOGICAL ANALYSIS
Authors: SHAIKH NAJMA , BHORAT HAROON 
Published: January 2006

AbstractThis study, through an exploratory, but promising methodology, provides a tentative analysis of the relationship between HIV, poverty and labour markets. This was undertaken through the use of the October Household Survey of 1999 and the Antenatal Clinic Survey of 1998. It is clear from the paper that the relationship between poverty, labour markets and HIV is not homogeneous but multi‐dimensional in character. The analysis examines these interrelationships at both the household and individual level. The preliminary key finding from the analysis is that imputed HIV positive women come from poorer households than imputed negative women, but this observed difference is small. It is suggested that the analysis be repeated using larger samples of data, such as that now available from Census 2001
BUDGETING FOR HIV/AIDS IN SOUTH AFRICA: AN ANALYSIS OF PROVINCIAL HEALTH BUDGETS
Authors: HICKEY ALISON , NDLOVU NHLANHLA 
Published: January 2006

AbstractWhat is the best way to deliver funds to the provinces for HIV/AIDS interventions? This article analyses HIV/AIDS conditional grant (CG) spending and assesses the success of the new funding approach introduced in 2002/3 which channels HIV/AIDS funds to the provinces via the equitable share grant. Our research shows that on the whole provinces are improving their spending on the HIV/AIDS conditional grants and provinces are also beginning to allocate substantial funds from their own provincial budgets for HIV/AIDS interventions in the health sector. Special emphasis is placed on (a) provinces' initiative to allocate additional funds to HIV/AIDS from their own budgets; (b) variances in per capita spending on HIV‐positive and AIDS sick populations across provinces; and (c) whether prioritisation of HIV/AIDS in health budgets might be squeezing out spending on other health services.
Statistical Modeling of the Temperatures in the Northern Hemisphere Using Fractional Integration Techniques
Authors: Gil-Alana Luis A. 
Published: January 2006

AbstractThe temperatures in the Northern Hemisphere from 1854 to 1999 have been analyzed in this article by means of a testing procedure that permits one to consider fractional degrees of integration. The tests are valid under general forms of serial correlation and deterministic trends and do not require estimation of the fractional differencing parameter. The results show that the series follows a fractionally integrated process with the order of integration higher than zero and thus implying long memory behavior. The series was decomposed into four different subsamples, and it was observed that the degree of dependence between the observations substantially increased during the twentieth century.
Impact of Sea Surface Temperature and Soil Moisture on Seasonal Rainfall Prediction over the Sahel
Authors: Thiaw Wassila M. , Mo Kingtse C. 
Published: January 2006

Abstract
The ensemble rainfall forecasts over the Sahel for July–September (JAS) from the NCEP Coupled Forecast System (CFS) were evaluated for the period 1981–2002. The comparison with the gauge-based precipitation analysis indicates that the predicted Sahel rainfall is light and exhibits little interannual variability. The rain belt is shifted about 4° southward.
One major source of rainfall errors comes from the erroneous sea surface temperature (SST) forecasts. The systematic SST error pattern has positive errors in the North Pacific and the North Atlantic and negative errors in the tropical Pacific and the southern oceans. It resembles the decadal SST mode, which has a significant influence on rainfall over the Sahel. Because the systematic SST errors were not corrected during the forecasts, persistent errors serve as an additional forcing to the atmosphere.
The second source of error is from the soil moisture feedback, which contributes to the southward shift of rainfall and dryness over West Africa. This was demonstrated by the comparison between simulations (SIMs) and the Atmospheric Model Intercomparison Project (AMIP) run. Both are forced with observed SSTs. The SIMs initialized at the end of June have realistic soil moisture and do not show the southward shift of rainfall. The AMIP, which predicts soil moisture, maintains the dryness through the summer over the Sahel. For AMIP, the decreased rainfall is contributed by the decreased evaporation (E) due to the dry soil and the shift of the large temperature gradients southward. In response, the African easterly jet (AEJ) shifts southward. Since this jet is the primary source of energy for the African waves and their associated mesoscale convective systems, these too shift southward. This negative feedback contributes to increased dryness over the Sahel.
Surface Contribution to Planetary Albedo Variability in Cryosphere Regions
Authors: Qu Xin , Hall Alex 
Published: January 2006

Abstract
Climatological planetary albedo obtained from the International Satellite Cloud Climatology Project (ISCCP) D-series flux dataset is broken down into contributions from the surface and atmosphere in cryosphere regions. The atmosphere accounts for much more of climatological planetary albedo (≥75%) than the surface at all times of the year. The insignificance of the surface contribution over highly reflective cryosphere regions is attributed mostly to the damping effect of the atmosphere. The overlying atmosphere attenuates the surface’s contribution to climatological planetary albedo by reducing the number of solar photons initially reaching the surface and the number of photons initially reflected by the surface that actually reach the top of the atmosphere.
The ISCCP datasets were also used to determine the relative contributions of the surface and atmosphere to seasonal and interannual planetary albedo variability in cryosphere regions. Even damped by the atmosphere to the same degree as in the climatological case, the surface contribution dominates the variability in planetary albedo on seasonal and interannual time scales. The surface accounts for about 75% of the change in climatological planetary albedo from one season to another with similar zenith angle and more than 50% of its interannual variability at nearly all times of the year, especially during seasons with extensive snow and sea ice extent. The dominance of the surface in planetary albedo variability is because surface albedo variability associated with snow and ice fluctuations is significantly larger than atmospheric albedo variability due to cloud fluctuations. The large effect of snow and ice variations on planetary albedo variability suggests that if cloud fields do not change much in a future warmer climate, a retreat of snow cover or sea ice would lead to a significant increase in net incoming solar radiation, resulting in an enhancement of high-latitude climate sensitivity.
Climatology and Interannual Variability of North Atlantic Hurricane Tracks
Authors: Xie Lian , Yan Tingzhuang , Pietrafesa Leonard J. , Morrison John M. , Karl Thomas 
Published: January 2006

Abstract
The spatial and temporal variability of North Atlantic hurricane tracks and its possible association with the annual hurricane landfall frequency along the U.S. East Coast are studied using principal component analysis (PCA) of hurricane track density function (HTDF). The results show that, in addition to the well-documented effects of the El Niño–Southern Oscillation (ENSO) and vertical wind shear (VWS), North Atlantic HTDF is strongly modulated by the dipole mode (DM) of Atlantic sea surface temperature (SST) as well as the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO). Specifically, it was found that Atlantic SST DM is the only index that is associated with all top three empirical orthogonal function (EOF) modes of the Atlantic HTDF. ENSO and tropical Atlantic VWS are significantly correlated with the first and the third EOF of the HTDF over the North Atlantic Ocean. The second EOF of North Atlantic HTDF, which represents the “zonal gradient” of North Atlantic hurricane track density, showed no significant correlation with ENSO or with tropical Atlantic VWS. Instead, it is associated with the Atlantic SST DM, and extratropical processes including NAO and AO. Since for a given hurricane season, the preferred hurricane track pattern, together with the overall basinwide hurricane activity, collectively determines the hurricane landfall frequency, the results provide a foundation for the construction of a statistical model that projects the annual number of hurricanes striking the eastern seaboard of the United States.
North Atlantic Oscillation Response to Anomalous Indian Ocean SST in a Coupled GCM
Authors: Bader Jürgen , Latif Mojib 
Published: January 2006

Abstract
The dominant pattern of atmospheric variability in the North Atlantic sector is the North Atlantic Oscillation (NAO). Since the 1970s the NAO has been well characterized by a trend toward its positive phase. Recent atmospheric general circulation model studies have linked this trend to a progressive warming of the Indian Ocean. Unfortunately, a clear mechanism responsible for the change of the NAO could not be given. This study provides further details of the NAO response to Indian Ocean sea surface temperature (SST) anomalies. This is done by conducting experiments with a coupled ocean–atmosphere general circulation model (OAGCM). The authors develop a hypothesis of how the Indian Ocean impacts the NAO.
Reorganization of Tropical Climate during El Niño: A Weak Temperature Gradient Approach
Authors: Lintner Benjamin R. , Chiang John C. H. 
Published: January 2006

Abstract
The applicability of a weak temperature gradient (WTG) formulation for the reorganization of tropical climate during El Niño–Southern Oscillation (ENSO) events is investigated. This idealized dynamical framework solves for the divergent portion of the tropical circulation by assuming a spatially homogeneous perturbation temperature profile and a mass balance constraint applied over the tropical belt. An intermediate-level complexity model [the Quasi-Equilibrium Tropical Circulation Model (QTCM)] configured with the WTG assumptions is used to simulate El Niño conditions and is found to yield an appropriate level of tropospheric warming, a plausible pattern of precipitation anomalies in the tropical Pacific source region of El Niño, and a gross precipitation deficit over the Tropics outside the Pacific (hereafter the “remote Tropics”). Additional tests of the WTG framework with La Niña forcing conditions and enhanced greenhouse gas concentrations support its applicability. However, the ENSO response under the WTG framework fails in some respects when compared to the standard QTCM: in particular, some regional features of the anomalous precipitation response, especially in the remote Tropics, differ markedly between the two model versions. These discrepancies appear to originate in part from the lack of anomalous tropospheric temperature gradients (and circulations) in the framework presented here. Nevertheless, the WTG approach appears to be a useful lowest-order model for the tropical climate adjustment to ENSO. The WTG framework is also used to argue that El Niño may not represent a good proxy for tropical rainfall changes under greenhouse gas warming scenarios because the large-scale subsidence occurring with the tropospheric warming in the El Niño scenario has an effect on rainfall that is distinct from the effect of increased tropospheric temperatures common to both the greenhouse gas warming and El Niño scenarios.
Why Are There Tropical Warm Pools?
Authors: Clement Amy C. , Seager Richard , Murtugudde Raghu 
Published: January 2006

Abstract
Tropical warm pools appear as the primary mode in the distribution of tropical sea surface temperature (SST). Most previous studies have focused on the role of atmospheric processes in homogenizing temperatures in the warm pool and establishing the observed statistical SST distribution. In this paper, a hierarchy of models is used to illustrate both oceanic and atmospheric mechanisms that contribute to the establishment of tropical warm pools. It is found that individual atmospheric processes have competing effects on the SST distribution: atmospheric heat transport tends to homogenize SST, while the spatial structure of atmospheric humidity and surface wind speeds tends to remove homogeneity. The latter effects dominate, and under atmosphere-only processes there is no warm pool. Ocean dynamics counter this effect by homogenizing SST, and it is argued that ocean dynamics is fundamental to the existence of the warm pool. Under easterly wind stress, the thermocline is deep in the west and shallow in the east. Because of this, poleward Ekman transport of water at the surface, compensated by equatorward geostrophic flow below and linked by equatorial upwelling, creates a cold tongue in the east but homogenizes SST in the west, creating a warm pool. High clouds may also homogenize the SST by reducing the surface solar radiation over the warmest water, but the strength of this feedback is quite uncertain. Implications for the role of these processes in climate change are discussed.
Intercomparison of Near-Surface Temperature and Precipitation Extremes in AMIP-2 Simulations, Reanalyses, and Observations
Authors: Kharin Viatcheslav V. , Zwiers Francis W. , Zhang Xuebin 
Published: January 2006

AbstractThe extremes of near-surface temperature and 24-h and 5-day mean precipitation rates are examined in simulations performed with atmospheric general circulation models (AGCMs) participating in the second phase of the Atmospheric Model Intercomparison Project (AMIP-2). The extremes are evaluated in terms of 20-yr return values of annual extremes. The model results are validated against the European Centre for Medium-Range Weather Forecasts and National Centers for Environmental Prediction reanalyses and station data. Precipitation extremes are also validated against the pentad dataset of the Global Precipitation Climatology Project, which is a blend of rain gauge observations, satellite data, and model output.On the whole, the AGCMs appear to simulate temperature extremes reasonably well. Model disagreements are larger for cold extremes than for warm extremes, particularly in wet and cloudy regions, and over sea ice and snow-covered areas. Many models exhibit an exaggerated clustering behavior for temperatures near the freezing point of water. Precipitation extremes are less reliably reproduced by the models and reanalyses. The largest disagreements are found in the Tropics where the parameterizations of deep convection affect the simulated daily precipitation extremes.
Tropical–North Pacific Climate Linkages over the Past Four Centuries*
Authors: D’Arrigo Rosanne , Wilson Rob , Deser Clara , Wiles Gregory , Cook Edward , Villalba Ricardo , Tudhope Alexander , Cole Julia , Linsley Braddock 
Published: January 2006

Abstract
Analyses of instrumental data demonstrate robust linkages between decadal-scale North Pacific and tropical Indo-Pacific climatic variability. These linkages encompass common regime shifts, including the noteworthy 1976 transition in Pacific climate. However, information on Pacific decadal variability and the tropical high-latitude climate connection is limited prior to the twentieth century. Herein tree-ring analysis is employed to extend the understanding of North Pacific climatic variability and related tropical linkages over the past four centuries. To this end, a tree-ring reconstruction of the December–May North Pacific index (NPI)—an index of the atmospheric circulation related to the Aleutian low pressure cell—is presented (1600–1983). The NPI reconstruction shows evidence for the three regime shifts seen in the instrumental NPI data, and for seven events in prior centuries. It correlates significantly with both instrumental tropical climate indices and a coral-based reconstruction of an optimal tropical Indo-Pacific climate index, supporting evidence for a tropical–North Pacific link extending as far west as the western Indian Ocean. The coral-based reconstruction (1781–1993) shows the twentieth-century regime shifts evident in the instrumental NPI and instrumental tropical Indo-Pacific climate index, and three previous shifts. Changes in the strength of correlation between the reconstructions over time, and the different identified shifts in both series prior to the twentieth century, suggest a varying tropical influence on North Pacific climate, with greater influence in the twentieth century. One likely mechanism is the low-frequency variability of the El Niño–Southern Oscillation (ENSO) and its varying impact on Indo-Pacific climate.