bluuebunny/crossref_metadata_2025 huggingface dataset:
A 14,300-year-long record of fire–vegetation–climate linkages at Battle Ground Lake, southwestern Washington
Authors: Walsh Megan K. , Whitlock Cathy , Bartlein Patrick J.
Published: July 2008

High-resolution macroscopic charcoal analysis was used to reconstruct a 14,300-year-long fire history record from the lower Columbia River Valley in southwestern Washington, which was compared to a previous vegetation reconstruction for the site. In the late-glacial period (ca. 14,300-13,100 cal yr BP), Pinus/Picea-dominated parkland supported little to no fire activity. From the late-glacial to the early Holocene (ca. 13,100-10,800 cal yr BP), Pseudotsuga/Abies-dominated forest featured more frequent fire episodes that burned mostly woody vegetation. In the early to middle Holocene (ca. 10,800-5200 cal yr BP), Quercus-dominated savanna was associated with frequent fire episodes of low-to-moderate severity, with an increased herbaceous (i.e., grass) charcoal content. From the middle to late Holocene (ca. 5200 cal yr BP to present), forest dominated by Pseudotsuga, Thuja-type, and Tsuga heterophylla supported less frequent, but mostly large or high-severity fire episodes. Fire episodes were least frequent, but were largest or most severe, after ca. 2500 cal yr BP. The fire history at Battle Ground Lake was apparently driven by climate, directly through the length and severity of the fire season, and indirectly through climate-driven vegetation shifts, which affected available fuel biomass.
Prevalence and predictors of vitamin D inadequacy amongst Lebanese osteoporotic women
Authors: Gannagé-Yared Marie-Hélène , Maalouf Ghassan , Khalife Simon , Challita Samir , Yaghi Yasser , Ziade Nelly , Chalfoun Amal , Norquist Josephine , Chandler Julie
Published: July 2008

In Middle-Eastern countries, more particularly in Lebanon, the incidence of vitamin D deficiency has been found to be surprisingly high in schoolchildren and young individuals. However, the prevalence and risk factors for vitamin D inadequacy amongst Lebanese osteoporotic women seeking medical health care has never been studied. We analysed vitamin D-inadequacy risk factors among the 251 Lebanese postmenopausal osteoporotic women (from both Muslim and Christian communities) who participated in a vitamin D international epidemiological study. Vitamin D inadequacy prevalence (25-hydroxyvitamin D (25(OH)D) < 30 ng/ml) was 84·9 %. 25(OH)D was negatively correlated with BMI (r − 0·41; P < 0·001) and positively correlated with educational level (r 0·37; P < 0·001) and self-reported general health (r 0·17; P < 0·01). No significant correlation was found with age and no seasonal variation was observed. There was no significant correlation between 25(OH)D and sun exposure index or vitamin D-rich food consumption. However, 25(OH)D strongly correlated with vitamin D supplement intake (r 0·48; P < 0·0001). Muslim community participants had lower 25(OH)D levels compared with their Christian counterparts (P < 0·001). They also had higher BMI, lower educational level and vitamin D supplement consumption and followed more frequently a dress code covering the arms (P < 0·0001 for all variables). In a multivariate model, in Muslims, inadequate vitamin D supplements and a dress code covering the arms are the independent predictors of 25(OH)D inadequacy (P < 0·001 for both variables). However, in Christians, the predictors are inadequate vitamin D supplements, high BMI and low educational level (P < 0·001; P = 0·002 and P = 0·02 respectively). There is an urgent need to increase vitamin D supplement use in Middle-Eastern osteoporotic women, more particularly in those from the Muslim community.
Predictors of 25-hydroxyvitamin D status among adults in two British national surveys
Authors: Hirani Vasant , Mosdøl Annhild , Mishra Gita
Published: July 2008

Several recent reports have found a high prevalence of vitamin D deficiency in the adult British population. The present paper investigates the associations of low income/material deprivation and other predictors of serum 25-hydroxyvitamin D (25(OH)D) status in two surveys: The National Diet and Nutrition Survey (NDNS) of the population aged 19–64 years in mainland Britain and the Low Income Diet and Nutrition Survey (LIDNS) of adults aged ≥ 19 years in all regions of the UK who were screened to identify low-income/materially deprived households. A valid serum 25(OH)D sample was obtained in 1297 and 792 participants from the NDNS and LDNS respectively. The NDNS participants who were not receiving benefits (n 1054) had a mean 25(OH)D of 50·1 nmol/l, which was higher than among NDNS participants receiving benefits (n 243) with a mean 25(OH)D of 43·0 nmol/l (P < 0·001) and the LIDNS sample (46·5 nmol/l; P < 0·05). For all three samples, the season of drawing blood, skin colour, dietary intake of vitamin D, and intake of dietary supplements were significant predictors (P < 0·05) of serum 25(OH)D status in mutually adjusted regression models. National prevention and treatments strategies of poor vitamin D status need to be targeted to include the adult population, particularly deprived populations, in addition to the elderly and ethnic minorities.
Picturing the Everyday Life of Limburg Miners: Photographs as a Historical Source
Authors: Januarius Joeri
Published: July 2008

Although recent years have seen growing theoretical interest among historians in the use of visual material, researchers continue to neglect the importance of photographs as source material. This is particularly striking since, now that iconographic material is becoming more widely available and archival institutions are beginning to place greater emphasis on visual material as use of the simple camera becomes more widespread, photographs often provide the only source of essential information for study. They illuminate the concept of the everyday, which in turn casts light on the significance of consumer goods, domestic comfort, the aspirations of men, women, and children, in short the banality of everyday life which echoed their mentalities and how they viewed the world.
Enchanted Edens and Nation-Making: Juana Manso, Education, Women and Trans-American Encounters in Nineteenth-Century Argentina
Authors: PEARD JULYAN G.
Published: July 2008

This article considers Juana Manso (1819–1875) as a crucial nation maker in nineteenth-century Argentina. Usually studied as a novelist, Manso was important beyond her literary production. As the first woman to be appointed to a government position and arguably the most radical feminist in nineteenth-century Argentina, Manso's story informs us about Argentine feminism and education, and illustrates how a woman, who lived in Uruguay, Brazil, United States and Cuba, became a crucial transmitter of ideas about emerging nations and a living example of the interconnectedness of the Americas.
Inequality, Institutions and Economic Growth in Latin America
Authors: COATSWORTH JOHN H.
Published: July 2008

This essay examines three recent historical approaches to the political economy of Latin America's relative economic backwardness. All three locate the origins of contemporary underdevelopment in defective colonial institutions linked to inequality. The contrasting view offered here affirms the significance of institutional constraints, but argues that they did not arise from colonial inequalities, but from the adaptation of Iberian practices to the American colonies under conditions of imperial weakness. Colonial inequality varied across the Americas; while it was not correlated with colonial economic performance, it mattered because it determined the extent of elite resistance to institutional modernisation after independence. The onset of economic growth in the mid to late nineteenth century brought economic elites to political power, but excluding majorities as inequality increased restrained the region's twentieth-century growth rates and prevented convergence.
ASYMPTOTICS AND CONSISTENT BOOTSTRAPS FOR DEA ESTIMATORS IN NONPARAMETRIC FRONTIER MODELS
Authors: Kneip Alois , Simar Léopold , Wilson Paul W.
Published: July 2008

Nonparametric data envelopment analysis (DEA) estimators based on linear programming methods have been widely applied in analyses of productive efficiency. The distributions of these estimators remain unknown except in the simple case of one input and one output, and previous bootstrap methods proposed for inference have not been proved consistent, making inference doubtful. This paper derives the asymptotic distribution of DEA estimators under variable returns to scale. This result is used to prove consistency of two different bootstrap procedures (one based on subsampling, the other based on smoothing). The smooth bootstrap requires smoothing the irregularly bounded density of inputs and outputs and smoothing the DEA frontier estimate. Both bootstrap procedures allow for dependence of the inefficiency process on output levels and the mix of inputs in the case of input-oriented measures, or on input levels and the mix of outputs in the case of output-oriented measures.
UNIT ROOT TEST IN A THRESHOLD AUTOREGRESSION: ASYMPTOTIC THEORY AND RESIDUAL-BASED BLOCK BOOTSTRAP
Authors: Seo Myung Hwan
Published: July 2008

This paper develops a test of the unit root null hypothesis against a stationary threshold process. This testing problem is nonstandard and complicated because a parameter is unidentified and the process is nonstationary under the null hypothesis. We derive an asymptotic distribution for the test, which is not pivotal without simplifying assumptions. A residual-based block bootstrap is proposed to calculate the asymptoticp-values. The asymptotic validity of the bootstrap is established, and a set of Monte Carlo simulations demonstrates its finite-sample performance. In particular, the test exhibits considerable power gains over the augmented Dickey–Fuller (ADF) test, which neglects threshold effects.
Wild sheep and livestock in Nepal Trans-Himalaya: coexistence or competition?
Authors: SHRESTHA RINJAN , WEGGE PER
Published: July 2008

Excessive grazing by livestock is claimed to displace wild ungulates in the Trans-Himalaya. This study compares the seasonal diets and habitat use of sympatric wild naurPseudois nayaurand domestic goatCapra hircus, sheepOvis ariesand free-ranging yakBos grunniensin north Nepal and analyses their overlap both within and across seasons. Alpine meadow and the legumesOxytropisandChesneyawere critical resources for all animal groups. High overlap occurred cross-seasonally when smallstock (sheep and goats) in summer used the spring and autumn ranges of naur. Relatively high total ungulate biomass (3028 kg km−2) and low recruitment of naur (56 young per 100 adult females in autumn) suggested interspecific competition. The spatio-temporal heterogeneity in composition and phenology of food plants across the steep gradient of altitude, together with rotational grazing, appears to indirectly facilitate coexistence of naur and smallstock. However, owing to high cross-seasonal (inter-seasonal) overlaps, competition is likely to occur between these two groups at high stocking densities. Within seasons, naur overlapped more with free-ranging yak than with smallstock. As their habitat use and diets were most similar in winter, when both fed extensively on the same species of shrubs, naur was most likely to compete with yak during that season.
Cost-effectiveness analysis of a hypothetical hepatitis C vaccine compared to antiviral therapy
Authors: MASSAD E. , COUTINHO F. A. B. , CHAIB E. , BURATTINI M. N.
Published: July 2008

We propose a mathematical model to simulate the dynamics of hepatitis C virus (HCV) infection in the state of São Paulo, Brazil. We assumed that a hypothetical vaccine, which cost was taken to be the initial cost of the vaccine against hepatitis B exists and it is introduced in the model. We computed its cost-effectiveness compared with the anti-HCV therapy. The calculated basic reproduction number was 1·20. The model predicts that without intervention a steady state exists with an HCV prevalence of 3%, in agreement with the current epidemiological data. Starting from this steady state three interventions were simulated: indiscriminate vaccination, selective vaccination and anti-HCV therapy. Selective vaccination proved to be the strategy with the best cost-effectiveness ratio, followed by indiscriminate vaccination and anti-HCV therapy.
Recognition of facial emotion in low vision: A flexible usage of facial features
Authors: BOUCART MURIEL , DINON JEAN-FRANÇOIS , DESPRETZ PASCAL , DESMETTRE THOMAS , HLADIUK KATRINE , OLIVA AUDE
Published: July 2008

Age-related macular degeneration (AMD) is a major cause of visual impairment in people older than 50 years in Western countries, affecting essential tasks such as reading and face recognition. Here we investigated the mechanisms underlying the deficit in recognition of facial expressions in an AMD population with low vision. Pictures of faces displaying different emotions with the mouth open or closed were centrally displayed for 300 ms. Participants with AMD with low acuity (mean 20/200) and normally sighted age-matched controls performed one of two emotion tasks: detecting whether a face had an expression or not (expressive/non expressive (EXNEX) task) or categorizing the facial emotion as happy, angry, or neutral (categorization of expression (CATEX) task). Previous research has shown that healthy observers are mainly using high spatial frequencies in an EXNEX task while performance at a CATEX task was preferentially based on low spatial frequencies. Due to impaired processing of high spatial frequencies in central vision, we expected and observed that AMD participants failed at deciding whether a face was expressive or not but categorized normally the emotion of the face (e.g., happy, angry, neutral). Moreover, we observed that AMD participants mostly identified emotions using the lower part of the face (mouth). Accuracy did not differ between the two tasks for normally sighted observers. The results indicate that AMD participants are able to identify facial emotion but must base their decision mainly on the low spatial frequencies, as they lack the perception of finer details.
The Vertex Degree Distribution of Passive Random Intersection Graph Models
Authors: JAWORSKI JERZY , STARK DUDLEY
Published: July 2008

In a random passive intersection graph model the edges of the graph are decided by taking the union of a fixed number of cliques of random size. We give conditions for a random passive intersection graph model to have a limiting vertex degree distribution, in particular to have a Poisson limiting vertex degree distribution. We give related conditions which, in addition to implying a limiting vertex degree distribution, imply convergence of expectation.
Judicial navigation as official law meets culture in Turkey
Authors: Örücü Esin
Published: July 2008

This article aims to assess the work of the courts as navigators when law meets culture in Turkey, where the culture of the official legal system and the culture of the people do not always accord. First the conceptual framework used is analysed, then readers are introduced to the peculiarities of Turkish law and socioculture, and finally, the work of the judge is considered. Selected cases are in three groups: cases where courts face culture contrary to the vision embodied in the official legal framework; then, where courts face culture which can be catered for within the legal framework, though not in keeping with it, and now need revision because of the aspired European Union membership; and finally, where courts face demands of further Europeanisation and human rights law from the outside, which may or may not fit in the framework or the traditional values of the people.
Simulation of the formation of O+ density troughs at 6000 km altitude in the polar cap ionosphere‐magnetosphere region
Authors: Jaafari Fajer , Horwitz J. L. , Zeng W.
Published: July 2008

Spacecraft‐based in situ observations have indicated considerable variability in O+ densities in the polar cap ionosphere‐magnetosphere region near 6000 km altitude, from above 10 O+ cm−3 to lower than 0.01 O+ cm−3. Regions with densities in the low range have been referred to as O+ density troughs or ion depletion zones at these altitudes. In this paper, we use the UT Arlington Dynamic Fluid‐Kinetic (DyFK) ionospheric plasma transport model to simulate O+ density profiles under various conditions, in order to reproduce O+ densities which were observed by the Thermal Ion Dynamics Experiment (TIDE) on the Polar spacecraft on 20 August 1998 near Polar perigee. Using solar wind parameters and IMF conditions as inputs driving the time‐varying high‐latitude electric potential model and incorporating auroral processes involving the effects of soft electron precipitation and wave‐driven transverse ion heating, we simulate the ionosphere‐magnetosphere plasma transport and the associated O+ bulk parameter profiles within four flux tubes convecting in the high‐latitude region. The principal competing processes controlling the O+ density levels at these altitudes are the auroral processes, which elevate the O+ densities in the ∼6000 km altitude region, and the effects of F region O+‐electron recombination in darkness, which decrease the O+ densities at higher altitudes through draining to the reduced F region ionosphere. Depending chiefly upon the flux tube convection trajectories and their relationship to estimated auroral oval locations, both elevated and trough‐like densities are seen at ∼6000 km altitudes in the simulations, as observed by Polar/TIDE in the polar cap magnetosphere.
Tidal and spring‐neap variations in horizontal dispersion in a partially mixed estuary
Authors: Geyer W. R. , Chant R. , Houghton R.
Published: July 2008

A sequence of dye releases in the Hudson River estuary provide a quantitative assessment of horizontal dispersion in a partially mixed estuary. Dye was released in the bottom boundary layer on 4 separate occasions, with varying tidal phase and spring‐neap conditions. The three‐dimensional distribution of dye was monitored by two vessels with in situ, profiling fluorometers. The three‐dimensional spreading of the dye was estimated by calculating the time derivative of the second moment of the dye in the along‐estuary, cross‐estuary and vertical directions. The average along‐estuary dispersion rate was about 100 m2/s, but maximum rates up to 700 m2/s occurred during ebb tides, and minimum rates occurred during flood. Vertical shear dispersion was the principal mechanism during neap tides, but transverse shear dispersion became more important during springs. Suppression of mixing across the pycnocline limited the vertical extent of the patch in all but the maximum spring‐tide conditions, with vertical diffusivities in the pycnocline estimated at 4 × 10−5 m2/s during neaps. The limited vertical extent of the dye patch limited the dispersion of the dye relative to the overall estuarine dispersion rate, which was an order of magnitude greater than that of the dye. This study indicates that the effective dispersion of waterborne material in an estuary depends sensitively on its vertical distribution as well as the phase of the spring‐neap cycle.
Crop area estimation using high and medium resolution satellite imagery in areas with complex topography
Authors: Husak G. J. , Marshall M. T. , Michaelsen J. , Pedreros D. , Funk C. , Galu G.
Published: July 2008

Reliable estimates of cropped area (CA) in developing countries with chronic food shortages are essential for emergency relief and the design of appropriate market‐based food security programs. Satellite interpretation of CA is an effective alternative to extensive and costly field surveys, which fail to represent the spatial heterogeneity at the country‐level. Bias‐corrected, texture based classifications show little deviation from actual crop inventories, when estimates derived from aerial photographs or field measurements are used to remove systematic errors in medium resolution estimates. In this paper, we demonstrate a hybrid high‐medium resolution technique for Central Ethiopia that combines spatially limited unbiased estimates from IKONOS images, with spatially extensive Landsat ETM+ interpretations, land‐cover, and SRTM‐based topography. Logistic regression is used to derive the probability of a location being crop. These individual points are then aggregated to produce regional estimates of CA. District‐level analysis of Landsat based estimates showed CA totals which supported the estimates of the Bureau of Agriculture and Rural Development. Continued work will evaluate the technique in other parts of Africa, while segmentation algorithms will be evaluated, in order to automate classification of medium resolution imagery for routine CA estimation in the future.
An upper tropospheric humidity data set from operational satellite microwave data
Authors: Buehler S. A. , Kuvatov M. , John V. O. , Milz M. , Soden B. J. , Jackson D. L. , Notholt J.
Published: July 2008

183.31 GHz observations from the Advanced Microwave Sounding Unit B (AMSU‐B) instruments onboard the NOAA 15, 16, and 17 satellites were used to derive a new data set of Upper Tropospheric Humidity (UTH). The data set consist of monthly median and mean data on a 1.5° latitude‐longitude grid between 60°S and 60°N, and covers the time period of January 2000 to February 2007. The data from all three instruments are very consistent, with relative difference biases of less than 4% and relative difference standard deviations of 7%. Radiometric contributions by high ice clouds and by the Earth's surface affect the measurements in certain areas. The uncertainty due to clouds is estimated to be up to approximately 10%RH in areas with deep convection. The uncertainty associated with contamination from surface emission can exceed 10%RH in midlatitude winter, where the data therefore should be regarded with caution. Otherwise the surface influence appears negligible. The paper also discusses the UTH median climatology and seasonal cycle, which are found to be broadly consistent with UTH climatologies from other sensors. Finally, the paper presents an initial validation of the new data set against IR satellite data and radiosonde data. The observed biases of up to 9%RH (wet bias relative to HIRS) were found to be broadly consistent with expectations based on earlier studies. The observed standard deviations against all other data sets were below 6%RH. The UTH data are available to the scientific community on http://www.sat.ltu.se.
The strongest desert dust intrusion mixed with smoke over the Iberian Peninsula registered with Sun photometry
Authors: Cachorro V. E. , Toledano C. , Prats N. , Sorribas M. , Mogo S. , Berjón A. , Torres B. , Rodrigo R. , de la Rosa J. , De Frutos A. M.
Published: July 2008

We present the analysis of the strongest North African desert dust (DD) intrusion that occurred over the Iberian Peninsula (IP) during the last decade, as registered by modern remote sensing techniques like Sun photometry. This event took place from 22 July to 3 August 2004. The most relevant features of this exceptional event, originated over the Saharan desert, were its great intensity and duration. We focus on the columnar aerosol properties measured by the AERONET‐Cimel photometers at El Arenosillo (southwest) and Palencia (north‐center) stations. Aerosol optical depth (AOD) reached a maximum of 2.7 at El Arenosillo during 22 July and 1.3 at Palencia on 23 July, with the Ånsgtröm exponent values near zero during the AOD peaks. In addition, PM10 concentration levels are also reported at various sites of the IP in order to establish the impact of this intrusion, reaching daily values as high as 200 μg/m3 and peaks near 600 μg/m3 in an hourly basis. The interest of this special event is increased because of the mixing with smoke particles from concurrent forest fires in the IP. Features of the columnar volume particle size distribution and derived microphysical parameters, the single scattering albedo, and a reliable estimation of the radiative forcing under these extreme conditions are also reported. Complementary information, as air mass back trajectories, synoptic charts, images, and AOD maps of satellite sensors (SeaWIFS, MODIS) together with NAAPS prognostic model, is used in the analysis in order to draw a detailed scenario of this dust‐smoke event over the IP.
Electromagnetic wave propagation in the surface‐ionosphere cavity of Venus
Authors: Simões F. , Hamelin M. , Grard R. , Aplin K. L. , Béghin C. , Berthelier J.‐J. , Besser B. P. , Lebreton J.‐P. , López‐Moreno J. J. , Molina‐Cuberos G. J. , Schwingenschuh K. , Tokano T.
Published: July 2008

The propagation of extremely low frequency (ELF) waves in the Earth surface‐ionosphere cavity and the properties of the related Schumann resonances have been extensively studied in order to explain their relation with atmospheric electric phenomena. A similar approach can be used to understand the electric environment of Venus and, more importantly, search for the evidence of possible atmospheric lightning activity, which remains a controversial issue. We revisit the available models for ELF propagation in the cavity of Venus, recapitulate the similarities and differences with other planets, and present a full wave propagation finite element model with improved parameterization. The new model introduces corrections for refraction phenomena in the atmosphere; it takes into account the day‐night asymmetry of the cavity and calculates the resulting eigenfrequency line splitting. The analytical and numerical approaches are validated against the very low frequency electric field data collected by Venera 11 and 12 during their descents through the atmosphere of Venus. Instrumentation suitable for the measurement of ELF waves in planetary atmospheres is briefly addressed.
Prediction of anisotropy from flow models: A comparison of three methods
Authors: Lev Einat , Hager Bradford H.
Published: July 2008

Observations of anisotropy in Earth are used regularly as constraints for models of deformation, using various assumptions about the relationship between deformation and the resulting anisotropic fabric. We compare three methods for calculating fabric from velocity fields: tracking of finite strain ellipses, a kinematic crystallographic code, and the evolution of directors. We find that the use of the finite strain ellipse provides only limited prediction capabilities, as it cannot reproduce experimental observations that involve recrystallization. The crystallographic code we tested (a variant of the popular code D‐Rex) provides a more complete fabric prediction, but at a much higher computational cost. The directors method provides an intermediate solution: while it does not include some of the more complex crystallographic processes that D‐Rex does, the results of this method closely resemble those of D‐Rex, at a lower computational cost. The directors are also capable of tracking anisotropy at much larger strains than D‐Rex. We conclude that when computation speed is important, for example, in self‐consistent geodynamic models with anisotropic rheology, the directors method provides an appropriate approximation.
Increased sensitivity of tropical cyclogenesis to wind shear in higher SST environments
Authors: Nolan David S. , Rappin Eric D.
Published: July 2008

A new method for evaluating the sensitivity of tropical cyclone (TC) genesis to environmental parameters involves the simulation of tropical cyclone development with a cloud‐resolving model in environments of radiative‐convective equilibrium (RCE) generated by the same model. This method is extended to allow for the incorporation of mean wind shear into the RCE states, thus providing much more realistic and relevant simulations of TC genesis. The “finite‐amplitude” nature of tropical cyclogenesis is reproduced, with cyclogenesis resulting only when the initial vortex strength is sufficient, which in turn depends on the environmental parameters. For fixed thermodynamic parameters, the required initial vortex strength necessary for genesis increases with the mean wind shear. However, an unexpected result has been obtained, that increasing sea surface temperature (SST) does not allow TC genesis to overcome greater shear. In fact, the opposite trend is found, that shear is more effective in suppressing TC genesis when the SST is higher. This increased sensitivity can be explained by several factors, such as the higher altitude of the developing mid‐level vortex, stronger downdrafts, and increased static stability, all of which allow the shear to be more effective in disrupting the developing cyclone
Pacific bidecadal climate variability regulated by tidal mixing around the Kuril Islands
Authors: Hasumi Hiroyasu , Yasuda Ichiro , Tatebe Hiroaki , Kimoto Masahide
Published: July 2008

18.6‐year period variability has been detected in various aspects of the climate, especially in and around the Pacific Ocean. Although it is believed to be caused by 18.6‐year period tidal cycle, no study has directly shown how the tidal cycle regulates such variability. Using a state‐of‐the‐art climate model, we show that the 18.6‐year cycle in strong tidal mixing localized around the Kuril Islands induces 18.6‐year periodicity in El Nino‐Southern Oscillation‐like Pacific climate variability. Influence of the tidal mixing propagates along the Pacific western rim as coastally trapped waves. Temperature anomaly is generated in the subsurface western equatorial Pacific, which propagates along the equatorial thermocline and eventually excites 18.6‐year periodicity in the equatorial sea surface temperature.
Geology of Shackleton Crater and the south pole of the Moon
Authors: Spudis Paul D. , Bussey Ben , Plescia Jeffrey , Josset Jean‐Luc , Beauvivre Stéphane
Published: July 2008

Using new SMART‐1 AMIE images and Arecibo and Goldstone high resolution radar images of the Moon, we investigate the geological relations of the south pole, including the 20 km‐diameter crater Shackleton. The south pole is located inside the topographic rim of the South Pole‐Aitken (SPA) basin, the largest and oldest impact crater on the Moon and Shackleton is located on the edge of an interior basin massif. The crater Shackleton is found to be older than the mare surface of the Apollo 15 landing site (3.3 Ga), but younger than the Apollo 14 landing site (3.85 Ga). These results suggest that Shackleton may have collected extra‐lunar volatile elements for at least the last 2 billion years and is an attractive site for permanent human presence on the Moon.
Dominant time scale for brittle fragmentation of vesicular magma by decompression
Authors: Kameda Masaharu , Kuribara Hideaki , Ichihara Mie
Published: July 2008

Brittle fragmentation was examined in a vesicular material analogous to magma, in this case, maltose syrup with bubbles. All the key time scales for magma fragmentation are controlled in the experiment using a rapid decompression facility. It was found that the onset of fragmentation can be well characterized using the Maxwell relaxation time τr and the decompression time Δtdec, in the case where sufficiently large stress is generated in the material. As the ratio Δtdec/τr increases from less than unity to over fifty, the response of the specimen changes from brittle fragmentation to ductile expansion without fragmentation. During the transition, the specimen exhibits small ductile deformation before the onset of fragmentation. The transition occurs even though the stress at the bubble wall is the same. The results suggest that Δtdec/τr is the controlling parameter not only for the onset of, but also for the variation of magma fragmentation by decompression.
Optical estimation of auroral ion upflow: 2. A case study
Authors: Zettergren M. , Semeter J. , Blelly P.‐L. , Sivjee G. , Azeem I. , Mende S. , Gleisner H. , Diaz M. , Witasse O.
Published: July 2008

This work presents a detailed multi‐instrument and modeling case study of an ion upflow event occurring over the Sondrestrom incoherent scatter radar on 17 February 2001. This case study is used to demonstrate the effectiveness of a previously developed optical estimator of ion upflow. The optical estimator of ion upflow is applied in a two step process: (1) near‐infrared (NIR) optical observations in the 700–850 nm wavelength range are inverted to reconstruct the energy distribution of precipitating electrons then (2) the reconstructed precipitation is applied to a combined fluid‐kinetic model of the ionosphere (TRANSCAR) to estimate the plasma response to the auroral particles. Plasma parameters estimated by this procedure are compared with plasma parameters derived from incoherent scatter radar data recorded during the event and are shown to be in reasonably good agreement. However, this study highlights an important limitation of the estimation technique, the lack of a direct measure of the ambient ionospheric state (nighttime plasma density). Means for addressing this limitation are discussed and may eventually allow for estimation of ionospheric state parameters under certain conditions by using optical sensors.
Quorum sensing in Cyanobacteria: N-octanoyl-homoserine lactone release and response, by the epilithic colonial cyanobacterium Gloeothece PCC6909
Authors: Sharif Dilara I , Gallon John , Smith Chris J , Dudley Ed
Published: July 2008

Quorum sensing involving acyl homoserine lactones (AHLs) is a density-dependent form of intercellular communication that occurs in many different members of the group Proteobacteria. However, to date, there have been few investigations of its occurrence in cyanobacteria. Here, using both a bioreporter Agrobacterium tumefaciens NTL4 (PZLR4) and mass spectrometry, we provide evidence of N-octanoyl homoserine lactone (C8-AHL) production in axenic cultures of the cyanobacterium Gloeothece PCC6909 and its sheathless mutant PCC6909/1. Accumulation of C8-AHL in the culture medium of laboratory cultures of Gloeothece followed a pattern characteristic of the phenomenon of autoinduction, a common feature of functional AHL-based quorum-sensing systems. Analysis by two-dimensional gel electrophoresis showed that, in response to treatment with C8-AHL, early growth-stage cells of PCC6909/1 showed changes in expression of 43 proteins compared with untreated cells. Among the 15 proteins that showed more than a twofold change in expression were RuBisCo, glutamate synthase, chorismate synthase, a member of the LysR family of transcriptional regulators (all upregulated), and enolase and aldolase, both of which were downregulated. The significance of such changes in response to C8-AHL is discussed in relation to carbohydrate and amino-acid metabolism and involvement of Gloeothece in biofilms.
Factors Affecting Prevalence of Overweight Among 12‐ to 17‐year‐old Urban Adolescents in Hyderabad, India
Authors: Laxmaiah Avula , Nagalla Balakrishna , Vijayaraghavan Kamasamudram , Nair Mohanan
Published: July 2008

Objective: The problem of overweight and obesity is not confined only to developed countries but is also widely prevalent in developing countries. The objective of this study was to assess the prevalence of overweight and obesity as defined by the International Obesity Task Force (IOTF) among school‐age children in Hyderabad, India, and identify its associated factors.

Research Methods and Procedures: A cross‐sectional and institutional study, adopting a multistage stratified cluster sampling procedure, was carried out during 2003 on adolescents 12 to 17 years of age of both sexes from Hyderabad, India.

Results: The overall prevalence of overweight was 6.1% [95% confidence interval (CI): 4.2, 8.0] among boys and 8.2% among girls (CI: 6.0, 10.4); 1.6% and 1.0% were obese, respectively. The prevalence was significantly higher (p < 0.05) among adolescents who watched television ≥3 h/d (10.4%) or belonged to a high socioeconomic background (14.9%, p < 0.001), whereas it was significantly lower among those participating regularly in outdoor games ≥6 h/wk (3.1%, p < 0.004) and household activities ≥3 h/d (4.7%, p < 0.001). The logistic regression analysis revealed that the prevalence of overweight was 4 times higher among the adolescents of high socioeconomic status [odds ratio (OR): 4.1; CI: 2.25, 7.52], 3 times higher in those not participating in outdoor games (OR: 2.75; CI: 1.56, 4.72), and 1.92 times higher in those watching television ≥3 h/d (OR: 1.92; CI: 1.16, 3.18).

Discussion: This study confirmed the findings of earlier studies carried out in Western countries and emphasizes that regular physical exercise, doing household activities, regulated television viewing, and healthy eating behaviors could contribute to controlling overweight and obesity.
Reduced Adiposity in ob/ob Mice following Total Body Irradiation and Bone Marrow Transplantation
Authors: Ablamunits Vitaly , Weisberg Stuart P. , Lemieux Jacob E. , Combs Terry P. , Klebanov Simon
Published: July 2008

Objective: The objective of this study was to assess long‐term metabolic consequences of total body irradiation (TBI) and bone marrow transplantation. Severe obesity develops due to both hypertrophy and hyperplasia of adipocytes. We hypothesized that TBI would arrest adipose tissue growth and would affect insulin resistance (IR).

Research Methods and Procedures: We exposed 2‐month‐old female ob/ob mice to 8 Grays of TBI followed by bone marrow transplantation and tested the animals for body weight (BW) gain, body composition, blood glucose, and insulin sensitivity.

Results: Two months after TBI, irradiated mice stopped gaining BW, whereas non‐treated mice continued to grow. At the age of 9.5 months, body mass of irradiated mice was 60.6 ± 1.4 grams, which was only 61% of that in non‐treated ob/ob controls (99.4 ± 1.6 grams). Body composition measurements by DXA showed that decreased BW was primarily due to an impaired fat accumulation. This could not result from the production of leptin by bone marrow‐derived adipocyte progenitors because inhibition of the obese phenotype was identical in recipients of both B6 and ob/ob bone marrow. Inability of the irradiated mice to accumulate fat was associated with hepatomegaly, lower levels of monocyte chemoattractant protein‐1 expression in adipose tissue, and increased IR.

Discussion: Our data argue in favor of the hypothesis that inability of adipose tissue to expand may increase IR. This mouse model may be valuable for studies of late‐onset radiation‐induced IR in humans.
Weight Loss and Health Outcomes in African Americans and Whites After Gastric Bypass Surgery
Authors: Anderson Wendy A. , Greene Geoffrey W. , Forse R. Armour , Apovian Caroline M. , Istfan Nawfal W.
Published: July 2008

Objective: The objective was to describe differences in weight loss, dietary intake, and cardiovascular risk factors between white and African‐American patients after gastric bypass (GBP).

Research Methods and Procedures: This was a retrospective database review of a sample of 84 adult patients (24 African‐American and 60 white women and men) between the ages of 33 and 53 years. All subjects had GBP surgery in 2001 at the Bariatric Surgery Program at Boston Medical Center in Boston, MA, and were followed for one year postoperatively. Patients were excluded if weight data were missing at baseline, 3 months, or 1 year after GBP. A total of 9 African Americans and 41 whites provided data at all 3 time‐points and were included in the study. Differences in weight loss, diet, and cardiovascular risk factors were analyzed.

Results: There were no differences in baseline characteristics between African Americans and whites. Mean weight loss for the entire sample was 36 ± 9%, with a range of 8% to 54% relative to initial body weight. Whites lost more weight (39 ± 8%) than African Americans (26 ± 10%) (p < 0.05). Dietary parameters, as well as improvements in blood pressure and lipid profiles, were similar in the two racial groups.

Discussion: Differences in weight loss between severely obese African Americans and whites undergoing open GBP are unlikely to be related to postoperative dietary practices. Our data are consistent with previous reports implicating metabolic differences between the two racial groups.
Sibutramine Plus Meal Replacement Therapy for Body Weight Loss and Maintenance in Obese Patients
Authors: Early James L. , Apovian Caroline M. , Aronne Louis J. , Fernstrom Madelyn H. , Frank Arthur , Greenway Frank L. , Heber David , Kushner Robert F. , Cwik Kristine M. , Walch Julia K. , Hewkin Ann C. , Blakesley Vicky
Published: July 2008

Objective: Our objective was to assess the efficacy and safety of sibutramine with a low‐calorie diet (LCD) and commercial meal‐replacement product in achieving weight loss and weight‐loss maintenance in obese patients.

Research Methods and Procedures: Eight U.S. centers recruited 148 obese patients for a 3‐month comprehensive weight‐loss therapy (Phase I) comprising daily sibutramine 10 mg + LCD (two Slim‐Fast meal‐replacement shakes, one low‐calorie meal; total kcal/d = 1200–1500). Patients (N = 113) who lost ≥5% of initial body weight during Phase I were randomized for a 9‐month period (Phase II) to daily sibutramine 15 mg + LCD (one meal‐replacement shake; two low‐calorie meals: total kcal/d ∼1200–1500) or daily placebo + three low‐calorie meals (total kcal/d ∼1200–1500). Both phases included behavior modification. Efficacy was assessed by body weight change during each phase and by the number of patients at endpoint maintaining ≥80% of the weight they had lost by the end of Phase I. Other outcomes included changes in cardiovascular and metabolic risk factors, adverse events, and vital signs.

Results: Mean body weight change during Phase I was −8.3 kg (p < 0.001). Patients randomized to sibutramine in Phase II had an additional −2.5 kg mean weight loss vs. a 2.8‐kg increase in the placebo group (p < 0.001). More sibutramine patients maintained ≥80% of their Phase I weight loss at the end of Phase II (85.5% vs. placebo 36.7%, p < 0.001). Most adverse events were mild or moderate in severity, and all serious adverse events were unrelated to sibutramine.

Discussion: Sibutramine plus LCD with meal replacements and behavior modification is a safe and effective strategy for achieving and sustaining weight loss in obese patients.
A Green Tea Extract High in Catechins Reduces Body Fat and Cardiovascular Risks in Humans
Authors: Nagao Tomonori , Hase Tadashi , Tokimitsu Ichiro
Published: July 2008

Objective: The body fat reducing effect and reduction of risks for cardiovascular disease by a green tea extract (GTE) high in catechins was investigated in humans with typical lifestyles.

Research Methods and Procedures: Japanese women and men with visceral fat‐type obesity were recruited for the trial. After a 2‐week diet run‐in period, a 12‐week double‐blind parallel multicenter trial was performed, in which the subjects ingested green tea containing 583 mg of catechins (catechin group) or 96 mg of catechins (control group) per day. Randomization was stratified by gender and body mass index at each medical institution. The subjects were instructed to maintain their usual dietary intake and normal physical activity.

Results: Data were analyzed using per‐protocol samples of 240 subjects (catechin group; n = 123, control group; n = 117). Decreases in body weight, body mass index, body fat ratio, body fat mass, waist circumference, hip circumference, visceral fat area, and subcutaneous fat area were found to be greater in the catechin group than in the control group. A greater decrease in systolic blood pressure (SBP) was found in the catechin group compared with the control group for subjects whose initial SBP was 130 mm Hg or higher. Low‐density lipoprotein (LDL) cholesterol was also decreased to a greater extent in the catechin group. No adverse effect was found.

Discussion: The continuous ingestion of a GTE high in catechins led to a reduction in body fat, SBP, and LDL cholesterol, suggesting that the ingestion of such an extract contributes to a decrease in obesity and cardiovascular disease risks.
Exercise Effect on Weight and Body Fat in Men and Women
Authors: McTiernan Anne , Sorensen Bess , Irwin Melinda L. , Morgan Angela , Yasui Yutaka , Rudolph Rebecca E. , Surawicz Christina , Lampe Johanna W. , Lampe Paul D. , Ayub Kamran , Potter John D.
Published: July 2008

Objectives: The effect of national exercise recommendations on adiposity is unknown and may differ by sex. We examined long‐term effects of aerobic exercise on adiposity in women and men.

Research Methods and Procedures: This was a 12‐month randomized, controlled clinical trial testing exercise effect on weight and body composition in men (N = 102) and women (N = 100). Sedentary/unfit persons, 40 to 75 years old, were recruited through physician practices and media. The intervention was facility‐ and home‐based moderate‐to‐vigorous intensity aerobic activity, 60 min/d, 6 days/wk vs. controls (no intervention).

Results: Exercisers exercised a mean 370 min/wk (men) and 295 min/wk (women), and seven dropped the intervention. Exercisers lost weight (women, −1.4 vs. +0.7 kg in controls, p = 0.008; men, −1.8 vs. −0.1 kg in controls, p = 0.03), BMI (women, −0.6 vs. +0.3 kg/m2 in controls, p = 0.006; men, −0.5 kg/m2 vs. no change in controls, p = 0.03), waist circumference (women, −1.4 vs. +2.2 cm in controls, p < 0.001; men, −3.3 vs. −0.4 cm in controls, p = 0.003), and total fat mass (women, −1.9 vs. +0.2 kg in controls, p = 0.001; men, −3.0 vs. +0.2 kg in controls, p < 0.001). Exercisers with greater increases in pedometer‐measured steps per day had greater decreases in weight, BMI, body fat, and intra‐abdominal fat (all p trend < 0.05 in both men and women). Similar trends were observed for increased minutes per day of exercise and for increases in maximal oxygen consumption.

Discussion: These data support the U.S. Department of Agriculture and Institute of Medicine guidelines of 60 min/d of moderate‐to‐vigorous physical activity.
Physical Activity Levels of Normal‐weight and Overweight Girls and Boys During Primary School Recess
Authors: Stratton Gareth , Ridgers Nicola D. , Fairclough Stuart J. , Richardson David J.
Published: July 2008

Objective: This study aimed to compare moderate‐to‐vigorous physical activity (MVPA) and vigorous physical activity (VPA) in normal‐weight and overweight boys and girls during school recess.

Research Methods and Procedures: Four hundred twenty children, age 6 to 10 years, were randomly selected from 25 schools in England. Three hundred seventy‐seven children completed the study. BMI was calculated from height and weight measurements, and heart rate reserve thresholds of 50% and 75% reflected children's engagement in MVPA and VPA, respectively.

Results: There was a significant main effect for sex and a significant interaction between BMI category and sex for the percent of recess time spent in MVPA and VPA. Normal‐weight girls were the least active group, compared with overweight boys and girls who were equally active. Fifty‐one boys and 24 girls of normal weight achieved the 40% threshold; of these, 30 boys and 10 girls exceeded 50% of recess time in MVPA. Eighteen overweight boys and 22 overweight girls exceeded the 40% threshold, whereas 8 boys and 8 girls exceeded the 50% threshold.

Discussion: Overweight boys were significantly less active than their normal‐weight male counterparts; this difference did not hold true for girls. Even though nearly double the number of normal‐weight children achieved the 40% of MVPA during recess compared with overweight children, physical activity promotion in school playgrounds needs to be targeted not only at overweight but at other health parameters, as 40 overweight children met the 40% MVPA target proposed for recess.