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Showing papers by "University of São Paulo published in 2005"


Journal ArticleDOI
TL;DR: Detailed estimates of dementia prevalence for each world region are believed to constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.

4,891 citations


Journal ArticleDOI
17 Aug 2005-JAMA
TL;DR: In this article, the period prevalence of acute renal failure (ARF) requiring renal replacement therapy (RRT) was found to be between 5% and 6% and was associated with a high hospital mortality rate.
Abstract: ContextAlthough acute renal failure (ARF) is believed to be common in the setting of critical illness and is associated with a high risk of death, little is known about its epidemiology and outcome or how these vary in different regions of the world.ObjectivesTo determine the period prevalence of ARF in intensive care unit (ICU) patients in multiple countries; to characterize differences in etiology, illness severity, and clinical practice; and to determine the impact of these differences on patient outcomes.Design, Setting, and PatientsProspective observational study of ICU patients who either were treated with renal replacement therapy (RRT) or fulfilled at least 1 of the predefined criteria for ARF from September 2000 to December 2001 at 54 hospitals in 23 countries.Main Outcome MeasuresOccurrence of ARF, factors contributing to etiology, illness severity, treatment, need for renal support after hospital discharge, and hospital mortality.ResultsOf 29 269 critically ill patients admitted during the study period, 1738 (5.7%; 95% confidence interval [CI], 5.5%-6.0%) had ARF during their ICU stay, including 1260 who were treated with RRT. The most common contributing factor to ARF was septic shock (47.5%; 95% CI, 45.2%-49.5%). Approximately 30% of patients had preadmission renal dysfunction. Overall hospital mortality was 60.3% (95% CI, 58.0%-62.6%). Dialysis dependence at hospital discharge was 13.8% (95% CI, 11.2%-16.3%) for survivors. Independent risk factors for hospital mortality included use of vasopressors (odds ratio [OR], 1.95; 95% CI, 1.50-2.55; P<.001), mechanical ventilation (OR, 2.11; 95% CI, 1.58-2.82; P<.001), septic shock (OR, 1.36; 95% CI, 1.03-1.79; P = .03), cardiogenic shock (OR, 1.41; 95% CI, 1.05-1.90; P = .02), and hepatorenal syndrome (OR, 1.87; 95% CI, 1.07-3.28; P = .03).ConclusionIn this multinational study, the period prevalence of ARF requiring RRT in the ICU was between 5% and 6% and was associated with a high hospital mortality rate.

3,706 citations


Journal ArticleDOI
TL;DR: In this paper, a field study of 29 resource-constrained firms that varied dramatically in their responses to similar objective environments is used to examine the process by which entrepreneurs in resource-poor environments were able to render unique services by recombining elements at hand for new purposes that challenged institutional definitions and limits.
Abstract: A field study of 29 resource-constrained firms that varied dramatically in their responses to similar objective environments is used to examine the process by which entrepreneurs in resource-poor environments were able to render unique services by recombining elements at hand for new purposes that challenged institutional definitions and limits. We found that Levi-Strauss's concept of bricolage—making do with what is at hand—explained many of the behaviors we observed in small firms that were able to create something from nothing by exploiting physical, social, or institutional inputs that other firms rejected or ignored. We demonstrate the socially constructed nature of resource environments and the role of bricolage in this construction. Using our field data and the existing literature on bricolage, we advance a formal definition of entrepreneurial bricolage and induce the beginnings of a process model of bricolage and firm growth. Central to our contribution is the notion that companies engaging in bri...

2,926 citations


Journal ArticleDOI
Joseph Adams1, Madan M. Aggarwal2, Zubayer Ahammed3, J. Amonett4  +363 moreInstitutions (46)
TL;DR: In this paper, the most important experimental results from the first three years of nucleus-nucleus collision studies at RHIC were reviewed, with emphasis on results of the STAR experiment.

2,750 citations


Journal ArticleDOI
K. Adcox1, S. S. Adler2, Serguei Afanasiev3, Christine Angela Aidala4  +550 moreInstitutions (48)
TL;DR: In this paper, the results of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) were examined with an emphasis on implications for the formation of a new state of dense matter.

2,572 citations



Journal ArticleDOI
TL;DR: In this article, the authors derived ages, total metallicities, and element ratios of 124 early-type galaxies in high and low-density environments, and analyzed the data by comparison with mock galaxy samples created through Monte Carlo simulations taking the typical average observational errors into account.
Abstract: The aim of this paper is to set constraints on the epochs of early-type galaxy formation through the archaeology of the stellar populations in local galaxies. Using our models of absorption-line indices that account for variable abundance ratios, we derive ages, total metallicities, and element ratios of 124 early-type galaxies in high- and low-density environments. The data are analyzed by comparison with mock galaxy samples created through Monte Carlo simulations taking the typical average observational errors into account, in order to eliminate artifacts caused by correlated errors. We find that all three parameters, age, metallicity, and ?/Fe ratio, are correlated with velocity dispersion. We show that these results are robust against recent revisions of the local abundance pattern at high metallicities. To recover the observed scatter we need to assume an intrinsic scatter of about 20% in age, 0.08?dex in [Z/H], and 0.05?dex in [?/Fe]. All low-mass objects with M* 1010 M? (? 130 km s-1) show evidence for the presence of intermediate-age stellar populations with low ?/Fe ratios. About 20% of the intermediate-mass objects with 1010 M*/M? 1011 [110 ?/(km s-1) 230; both elliptical and lenticular galaxies] must have either a young subpopulation or a blue horizontal branch. On the basis of the above relationships, valid for the bulk of the sample, we show that the Mg-? relation is mainly driven by metallicity, with similar contributions from the ?/Fe ratio (23%) and age (17%). We further find evidence for an influence of the environment on the stellar population properties. Massive early-type galaxies in low-density environments seem on average ~2?Gyr younger and slightly (~0.05-0.1?dex) more metal-rich than their counterparts in high-density environments. No offsets in the ?/Fe ratios are instead detected. With the aid of a simple chemical evolution model, we translate the derived ages and ?/Fe ratios into star formation histories. We show that most star formation activity in early-type galaxies is expected to have happened between redshifts ~3 and 5 in high-density environments and between redshifts 1 and 2 in low-density environments. We conclude that at least 50% of the total stellar mass density must have already formed at z ~ 1, in good agreement with observational estimates of the total stellar mass density as a function of redshift. Our results suggest that significant mass growth in the early-type galaxy population below z ~ 1 must be restricted to less massive objects, and a significant increase of the stellar mass density between redshifts 1 and 2 should be present, caused mainly by the field galaxy population. The results of this paper further imply the presence of vigorous star formation episodes in massive objects at z ~ 2-5 and evolved elliptical galaxies around z ~ 1, both observationally identified as SCUBA galaxies and extremely red objects, respectively.

1,668 citations


Journal ArticleDOI
Alasdair Ivens1, Christopher S. Peacock1, Elizabeth A. Worthey2, Lee Murphy1, Gautam Aggarwal2, Matthew Berriman1, Ellen Sisk2, Marie-Adèle Rajandream1, Ellen Adlem1, Rita Aert3, Atashi Anupama2, Zina Apostolou, Philip Attipoe2, Nathalie Bason1, Christopher Bauser4, Alfred Beck5, Stephen M. Beverley6, Gabriella Bianchettin7, K. Borzym5, G. Bothe4, Carlo V. Bruschi8, Carlo V. Bruschi7, Matt Collins1, Eithon Cadag2, Laura Ciarloni7, Christine Clayton, Richard M.R. Coulson9, Ann Cronin1, Angela K. Cruz10, Robert L. Davies1, Javier G. De Gaudenzi11, Deborah E. Dobson6, Andreas Duesterhoeft, Gholam Fazelina2, Nigel Fosker1, Alberto C.C. Frasch11, Audrey Fraser1, Monika Fuchs, Claudia Gabel, Arlette Goble1, André Goffeau12, David Harris1, Christiane Hertz-Fowler1, Helmut Hilbert, David Horn13, Yiting Huang2, Sven Klages5, Andrew J Knights1, Michael Kube5, Natasha Larke1, Lyudmila Litvin2, Angela Lord1, Tin Louie2, Marco A. Marra, David Masuy12, Keith R. Matthews14, Shulamit Michaeli, Jeremy C. Mottram15, Silke Müller-Auer, Heather Munden2, Siri Nelson2, Halina Norbertczak1, Karen Oliver1, Susan O'Neil1, Martin Pentony2, Thomas M. Pohl4, Claire Price1, Bénédicte Purnelle12, Michael A. Quail1, Ester Rabbinowitsch1, Richard Reinhardt5, Michael A. Rieger, Joel Rinta2, Johan Robben3, Laura Robertson2, Jeronimo C. Ruiz10, Simon Rutter1, David L. Saunders1, Melanie Schäfer, Jacquie Schein, David C. Schwartz16, Kathy Seeger1, Amber Seyler2, Sarah Sharp1, Heesun Shin, Dhileep Sivam2, Rob Squares1, Steve Squares1, Valentina Tosato7, Christy Vogt2, Guido Volckaert3, Rolf Wambutt, T. Warren1, Holger Wedler, John Woodward1, Shiguo Zhou16, Wolfgang Zimmermann, Deborah F. Smith17, Jenefer M. Blackwell18, Kenneth Stuart2, Kenneth Stuart19, Bart Barrell1, Peter J. Myler19, Peter J. Myler2 
15 Jul 2005-Science
TL;DR: The organization of protein-coding genes into long, strand-specific, polycistronic clusters and lack of general transcription factors in the L. major, Trypanosoma brucei, and Tritryp genomes suggest that the mechanisms regulating RNA polymerase II–directed transcription are distinct from those operating in other eukaryotes, although the trypanosomatids appear capable of chromatin remodeling.
Abstract: Leishmania species cause a spectrum of human diseases in tropical and subtropical regions of the world. We have sequenced the 36 chromosomes of the 32.8-megabase haploid genome of Leishmania major (Friedlin strain) and predict 911 RNA genes, 39 pseudogenes, and 8272 protein-coding genes, of which 36% can be ascribed a putative function. These include genes involved in host-pathogen interactions, such as proteolytic enzymes, and extensive machinery for synthesis of complex surface glycoconjugates. The organization of protein-coding genes into long, strand-specific, polycistronic clusters and lack of general transcription factors in the L. major, Trypanosoma brucei, and Trypanosoma cruzi (Tritryp) genomes suggest that the mechanisms regulating RNA polymerase II-directed transcription are distinct from those operating in other eukaryotes, although the trypanosomatids appear capable of chromatin remodeling. Abundant RNA-binding proteins are encoded in the Tritryp genomes, consistent with active posttranscriptional regulation of gene expression.

1,357 citations


Journal ArticleDOI
William C. Nierman1, William C. Nierman2, Arnab Pain3, Michael J. Anderson4, Jennifer R. Wortman2, Jennifer R. Wortman1, H. Stanley Kim2, H. Stanley Kim1, Javier Arroyo5, Matthew Berriman3, Keietsu Abe6, David B. Archer7, Clara Bermejo5, Joan W. Bennett8, Paul Bowyer4, Dan Chen1, Dan Chen2, Matthew Collins3, Richard Coulsen, Robert L. Davies3, Paul S. Dyer7, Mark L. Farman9, Nadia Fedorova1, Nadia Fedorova2, Natalie D. Fedorova1, Natalie D. Fedorova2, T. Feldblyum2, T. Feldblyum1, Reinhard Fischer10, Nigel Fosker3, Audrey Fraser3, José Luis García11, María Josefa Marcos García12, Ariette Goble3, Gustavo H. Goldman13, Katsuya Gomi6, Sam Griffith-Jones3, R. Gwilliam3, Brian J. Haas2, Brian J. Haas1, Hubertus Haas14, David Harris3, H. Horiuchi15, Jiaqi Huang1, Jiaqi Huang2, Sean Humphray3, Javier Jiménez12, Nancy P. Keller15, H. Khouri2, H. Khouri1, Katsuhiko Kitamoto16, Tetsuo Kobayashi17, Sven Konzack10, Resham Kulkarni1, Resham Kulkarni2, Toshitaka Kumagai18, Anne Lafton19, Jean-Paul Latgé19, Weixi Li9, Angela Lord3, Charles Lu2, Charles Lu1, William H. Majoros1, William H. Majoros2, Gregory S. May20, Bruce L. Miller21, Yasmin Ali Mohamoud2, Yasmin Ali Mohamoud1, María Molina5, Michel Monod22, Isabelle Mouyna19, Stephanie Mulligan1, Stephanie Mulligan2, Lee Murphy3, Susan O'Neil3, Ian T. Paulsen1, Ian T. Paulsen2, Miguel A. Peñalva11, Mihaela Pertea1, Mihaela Pertea2, Claire Price3, Bethan L. Pritchard4, Michael A. Quail3, Ester Rabbinowitsch3, Neil Rawlins3, Marie Adele Rajandream3, Utz Reichard23, Hubert Renauld3, Geoffrey D. Robson4, Santiago Rodríguez de Córdoba11, José Manuel Rodríguez-Peña5, Catherine M. Ronning2, Catherine M. Ronning1, Simon Rutter3, Steven L. Salzberg2, Steven L. Salzberg1, Miguel del Nogal Sánchez12, Juan C. Sánchez-Ferrero11, David L. Saunders3, Kathy Seeger3, Rob Squares3, S. Squares3, Michio Takeuchi24, Fredj Tekaia19, Geoffrey Turner25, Carlos R. Vázquez de Aldana12, J. Weidman1, J. Weidman2, Owen White1, Owen White2, John Woodward3, Jae-Hyuk Yu15, Claire M. Fraser1, Claire M. Fraser2, James E. Galagan26, Kiyoshi Asai18, Masayuki Machida18, Neil Hall3, Neil Hall1, Bart Barrell3, David W. Denning4 
22 Dec 2005-Nature
TL;DR: The Af293 genome sequence provides an unparalleled resource for the future understanding of this remarkable fungus and revealed temperature-dependent expression of distinct sets of genes, as well as 700 A. fumigatus genes not present or significantly diverged in the closely related sexual species Neosartorya fischeri, many of which may have roles in the pathogenicity phenotype.
Abstract: Aspergillus fumigatus is exceptional among microorganisms in being both a primary and opportunistic pathogen as well as a major allergen. Its conidia production is prolific, and so human respiratory tract exposure is almost constant. A. fumigatus is isolated from human habitats and vegetable compost heaps. In immunocompromised individuals, the incidence of invasive infection can be as high as 50% and the mortality rate is often about 50% (ref. 2). The interaction of A. fumigatus and other airborne fungi with the immune system is increasingly linked to severe asthma and sinusitis. Although the burden of invasive disease caused by A. fumigatus is substantial, the basic biology of the organism is mostly obscure. Here we show the complete 29.4-megabase genome sequence of the clinical isolate Af293, which consists of eight chromosomes containing 9,926 predicted genes. Microarray analysis revealed temperature-dependent expression of distinct sets of genes, as well as 700 A. fumigatus genes not present or significantly diverged in the closely related sexual species Neosartorya fischeri, many of which may have roles in the pathogenicity phenotype. The Af293 genome sequence provides an unparalleled resource for the future understanding of this remarkable fungus.

1,356 citations


Journal ArticleDOI
22 Dec 2005-Nature
TL;DR: The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution, and a comparative study with Aspergillus fumigatus and As pergillus oryzae, used in the production of sake, miso and soy sauce, provides new insight into eukaryotic genome evolution and gene regulation.
Abstract: The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.

1,297 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigate the power of spectral synthesis as a means to estimate the physical properties of galaxies, including stellar mass, velocity dispersion, extinction, and emission lines.
Abstract: The study of stellar populations in galaxies is entering a new era with the availability of large and high-quality data bases of both observed galactic spectra and state-of-the-art evolutionary synthesis models. In this paper we investigate the power of spectral synthesis as a means to estimate the physical properties of galaxies. Spectral synthesis is nothing more than the decomposition of an observed spectrum in terms of a superposition of a base of simple stellar populations of various ages and metallicities, producing as output the star formation and chemical histories of a galaxy, its extinction and velocity dispersion. Our implementation of this method uses the recent models of Bruzual & Charlot and observed spectra in the 3650–8000 A range. The reliability of this approach is studied by three different means: (1) simulations, (2) comparison with previous work based on a different technique, and (3) analysis of the consistency of results obtained for a sample of galaxies from the Sloan Digital Sky Survey (SDSS). We find that spectral synthesis provides reliable physical parameters as long as one does not attempt a very detailed description of the star formation and chemical histories. Robust and physically interesting parameters are obtained by combining the (individually uncertain) strengths of each simple stellar population in the base. In particular, we show that, besides providing excellent fits to observed galaxy spectra, this method is able to recover useful information on the distributions of stellar ages and, more importantly, stellar metallicities. Stellar masses, velocity dispersion and extinction are also found to be accurately retrieved for realistic signal-to-noise ratios. We apply this synthesis method to a volume-limited sample of 50 362 galaxies from the SDSS Data Release 2, producing a catalogue of stellar population properties. Emission lines are also studied, their measurement being performed after subtracting the computed starlight spectrum from the observed one. A comparison with recent estimates of both observed and physical properties of these galaxies obtained by other groups shows good qualitative and quantitative agreement, despite substantial differences in the methods of analysis. The confidence in the present method is further strengthened by several empirical and astrophysically reasonable correlations between synthesis results and independent quantities. For instance, we report the existence of strong correlations between stellar and nebular metallicities, stellar and nebular extinctions, mean stellar age and equivalent width of Hα and 4000-A break, and between stellar mass and velocity dispersion.

Journal ArticleDOI
TL;DR: The results indicate that left prefrontal anodal stimulation leads to an enhancement of working memory performance, which depends on the stimulation polarity and is specific to the site of stimulation.
Abstract: Previous studies have claimed that weak transcranial direct current stimulation (tDCS) induces persisting excitability changes in the human motor cortex that can be more pronounced than cortical modulation induced by transcranial magnetic stimulation, but there are no studies that have evaluated the effects of tDCS on working memory. Our aim was to determine whether anodal transcranial direct current stimulation, which enhances brain cortical excitability and activity, would modify performance in a sequential-letter working memory task when administered to the dorsolateral prefrontal cortex (DLPFC). Fifteen subjects underwent a three-back working memory task based on letters. This task was performed during sham and anodal stimulation applied over the left DLPFC. Moreover seven of these subjects performed the same task, but with inverse polarity (cathodal stimulation of the left DLPFC) and anodal stimulation of the primary motor cortex (M1). Our results indicate that only anodal stimulation of the left prefrontal cortex, but not cathodal stimulation of left DLPFC or anodal stimulation of M1, increases the accuracy of the task performance when compared to sham stimulation of the same area. This accuracy enhancement during active stimulation cannot be accounted for by slowed responses, as response times were not changed by stimulation. Our results indicate that left prefrontal anodal stimulation leads to an enhancement of working memory performance. Furthermore, this effect depends on the stimulation polarity and is specific to the site of stimulation. This result may be helpful to develop future interventions aiming at clinical benefits.

Journal ArticleDOI
TL;DR: It is concluded that HL feeding induces a local proinflammatory status in the hypothalamus, which results in impaired anorexigenic insulin signaling, which leads to a reduced caloric intake and weight loss.
Abstract: Obesity has reached epidemic proportions in several regions of the world. General changes in lifestyle, including consumption of fat-rich food, are among the most important factors leading to an unprecedented increase in the prevalence of this disease. Weight gain results from an imbalance between caloric intake and energy expenditure. Both of these parameters are under the tight control of specialized neurons of the hypothalamus that respond to peripheral anorexigenic and adipostatic signals carried by leptin and insulin. Here we show, by macroarray analysis, that high-fat feeding [hyperlipidic diet (HL)] induces the expression of several proinflammatory cytokines and inflammatory responsive proteins in hypothalamus. This phenomenon is accompanied by increased activation of c-Jun N-terminal kinase and nuclear factor-κB. In addition, HL feeding leads to impaired functional and molecular activation of the insulin-signaling pathway, which is paralleled by increased serine phosphorylation of the insulin rece...

Book ChapterDOI
11 Aug 2005
TL;DR: This paper describes a method to construct elliptic curves of prime order and embedding degree k = 12 and shows that the ability to handle log(D)/log(r) ~ (q–3)/(q–1) enables building curves with ρ ~ q/(q-1).
Abstract: Previously known techniques to construct pairing-friendly curves of prime or near-prime order are restricted to embedding degree $k \leqslant 6 $. More general methods produce curves over ${\mathbb F}_{p}$ where the bit length of p is often twice as large as that of the order r of the subgroup with embedding degree k; the best published results achieve ρ ≡ log(p)/log(r) ~ 5/4. In this paper we make the first step towards surpassing these limitations by describing a method to construct elliptic curves of prime order and embedding degree k = 12. The new curves lead to very efficient implementation: non-pairing operations need no more than ${\mathbb F}_{p^4}$ arithmetic, and pairing values can be compressed to one third of their length in a way compatible with point reduction techniques. We also discuss the role of large CM discriminants D to minimize ρ; in particular, for embedding degree k = 2q where q is prime we show that the ability to handle log(D)/log(r) ~ (q–3)/(q–1) enables building curves with ρ ~ q/(q–1).

Journal ArticleDOI
TL;DR: A detailed description of the pupil-corneal reflection technique is presented due to its claimed usability advantages, and it is shown that this method is still not quite appropriate for general interactive applications.

Journal ArticleDOI
TL;DR: In this paper, a model of holographic dark energy with an interaction with matter fields has been investigated, and it has been shown that the ratio of energy densities can vary with time.

Journal ArticleDOI
TL;DR: In this paper, the authors explored the effects that the composition and properties of atmospheric aerosol can have on the activation of droplets in warm clouds, so potentially influencing the magnitude of the indirect effect.
Abstract: The effects of atmospheric aerosol on climate forcing may be very substantial but are quantified poorly at present; in particular, the effects of aerosols on cloud radiative properties, or the "indirect effects" are credited with the greatest range of uncertainty amongst the known causes of radiative forcing. This manuscript explores the effects that the composition and properties of atmospheric aerosol can have on the activation of droplets in warm clouds, so potentially influencing the magnitude of the indirect effect. The effects of size, composition, mixing state and various derived properties are assessed and a range of these properties provided by atmospheric measurements in a variety of locations is briefly reviewed. The suitability of a range of process-level descriptions to capture these aerosol effects is investigated by assessment of their sensitivities to uncertainties in aerosol properties and by their performance in closure studies. The treatment of these effects within global models is reviewed and suggestions for future investigations are made.

Journal ArticleDOI
TL;DR: RNFL and ONH measurements had the best discriminating performance among the several Stratus OCT parameters and improved the diagnostic accuracy for glaucoma detection using this instrument.

Journal ArticleDOI
TL;DR: Traditional analytical protocols in current use are presented, and the influence of confounding variables on BPb levels are assessed and the significance of Pb determinations in human specimens including hair, nails, saliva, bone, blood, urine, feces, and exfoliated teeth are discussed.
Abstract: Lead concentration in whole blood (BPb) is the primary biomarker used to monitor exposure to this metallic element. The U.S. Centers for Disease Control and Prevention and the World Health Organization define a BPb of 10 microg/dL (0.48 micromol/L) as the threshold of concern in young children. However, recent studies have reported the possibility of adverse health effects, including intellectual impairment in young children, at BPb levels < 10 microg/dL, suggesting that there is no safe level of exposure. It appears impossible to differentiate between low-level chronic Pb exposure and a high-level short Pb exposure based on a single BPb measurement; therefore, serial BPb measurements offer a better estimation of possible health outcomes. The difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments (i.e., cycling of Pb between bone, blood, and soft tissues). If we are to differentiate more effectively between Pb stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose have yet been accepted by the scientific community as a reliable substitute for a BPb measurement. This review focuses on the limitations of biomarkers of Pb exposure and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use, and we attempt to assess the influence of confounding variables on BPb levels. Finally, we discuss the interpretation of BPb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of Pb determinations in human specimens including hair, nails, saliva, bone, blood (plasma, whole blood), urine, feces, and exfoliated teeth.

Journal ArticleDOI
03 Mar 2005-Nature
TL;DR: A high-resolution oxygen isotope record of a U/Th-dated stalagmite from subtropical southern Brazil, covering the past 116,200 years, finds that variations in rainfall source and amount are primarily driven by summer solar radiation, which is controlled by the Earth's precessional cycle.
Abstract: During the last glacial period, large millennial-scale temperature oscillations--the 'Dansgaard/Oeschger' cycles--were the primary climate signal in Northern Hemisphere climate archives from the high latitudes to the tropics. But whether the influence of these abrupt climate changes extended to the tropical and subtropical Southern Hemisphere, where changes in insolation are thought to be the main direct forcing of climate, has remained unclear. Here we present a high-resolution oxygen isotope record of a U/Th-dated stalagmite from subtropical southern Brazil, covering the past 116,200 years. The oxygen isotope signature varies with shifts in the source region and amount of rainfall in the area, and hence records changes in atmospheric circulation and convective intensity over South America. We find that these variations in rainfall source and amount are primarily driven by summer solar radiation, which is controlled by the Earth's precessional cycle. The Dansgaard/Oeschger cycles can be detected in our record and therefore we confirm that they also affect the tropical hydrological cycle, but that in southern subtropical Brazil, millennial-scale climate changes are not as dominant as they are in the Northern Hemisphere.

Journal ArticleDOI
TL;DR: Shrinkage stress development must be considered a multi-factorial phenomenon and accessing the specific contribution of volumetric shrinkage, viscoelastic behavior, reaction kinetics and local conditions on stress magnitude seems impractical.

Journal ArticleDOI
TL;DR: In this article, the optical properties of humic-like substances (HULIS) isolated from the fine fraction of biomass-burning aerosol collected in the Amazon basin during the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia? SMOke aerosols, Clouds, rainfall and Climate) experiment in September 2002 were analyzed.
Abstract: We present here the optical properties of humic-like substances (HULIS) isolated from the fine fraction of biomass-burning aerosol collected in the Amazon basin during the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia ? SMOke aerosols, Clouds, rainfall and Climate) experiment in September 2002. From the isolated HULIS, aerosol particles were generated and their scattering and absorption coefficients measured. The size distribution and mass of the particles were also recorded. The value of the index of refraction was derived from "closure" calculations based on particle size, scattering and absorption measurements. On average, the complex index of refraction at 532 nm of HULIS collected during day and nighttime was 1.65?0.0019i and 1.69?0.0016i, respectively. In addition, the imaginary part of the complex index of refraction was calculated using the measured absorption coefficient of the bulk HULIS. The mass absorption coefficient of the HULIS at 532 nm was found to be quite low (0.031 and 0.029 m2 g?1 for the day and night samples, respectively). However, due to the high absorption Angstrom exponent (6?7) of HULIS, the specific absorption increases substantially towards shorter wavelengths (~2?3 m2 g?1 at 300 nm), causing a relatively high (up to 50%) contribution to the light absorption of our Amazonian aerosol at 300 nm. For the relative contribution of HULIS to light absorption in the entire solar spectrum, lower values (6.4?8.6%) are obtained, but those are still not negligible.

Journal ArticleDOI
TL;DR: In some countries (China, Indonesia, the Kyrgyz Republic, the United States and Vietnam), dual burden households share sociodemographic profiles with overweight households, raising concerns for underweight individuals who may inadvertently become the focus of obesity prevention initiatives.
Abstract: OBJECTIVE: The purpose of this study is to document the prevalence of households with underweight and overweight persons (henceforth referred to as dual burden households) and their association with income and urban residence. The explorations by urban residence and income will test whether dual burden households differ from 'underweight only' and 'overweight only' households, respectively. These comparisons are relevant to differentiating or adapting nutrition-related interventions wherever obesity and undernutrition cluster at the household level. POPULATION: Data analysis is based on national surveys conducted in Brazil, China, Indonesia, the Kyrgyz Republic, Russia, Vietnam and the United States. METHODS: All persons were first classified into categories for underweight and overweight, using body mass index (BMI) cutoffs, and then all households were categorized into four types: dual burden, overweight, underweight and normal. Income and urban residence were explored as key risk factors for being a dual burden household, with the effects modeled separately for each country. Multiple logistic regression was used to explore income and urban risk factors, controlling for household size, region of residence and either urban residence or income, as appropriate. RESULTS: In six of the countries studied, 22-66% of households with an underweight person also had an overweight person. Countries with the highest prevalence of dual burden households were those in the middle range of gross national product (GNP). The dual burden household is easily distinguished from the 'underweight only' households in Brazil, China, Indonesia, the United States and Vietnam. In these five countries dual burden households were more likely to be urban and more likely to be among the highest income tertile. There were no significant differences between dual burden and 'underweight only' households in Russia and the Kyrgyz Republic. In contrast, dual burden households were not easily distinguished from the 'overweight only' households in China, Indonesia, the Kyrgyz Republic, the United States and Vietnam. In Brazil and Russia dual burden households were more likely to be lower income and urban than 'overweight only' households. CONCLUSION: The prevalence of dual burden households presents a significant public health concern, particularly for those countries in the middle range of GNP. In some countries (China, Indonesia, the Kyrgyz Republic, the United States and Vietnam), dual burden households share sociodemographic profiles with overweight households, raising concerns for underweight individuals who may inadvertently become the focus of obesity prevention initiatives. For this reason, obesity prevention efforts should focus on messages that are beneficial to the good health of all, such as increasing fruit and vegetable intake, improving overall diet quality and increasing physical activity.

Journal ArticleDOI
TL;DR: Self-destruction of collagen matrices occurs rapidly in resin-infiltrated dentin in vivo and may be arrested with the use of chlorhexidine as an MMP inhibitor.
Abstract: The recent paradigm that endogenous collagenolytic and gelatinolytic activities derived from acid-etched dentin result in degradation of hybrid layers requires in vivo validation. This study tested the null hypothesis that there is no difference between the degradation of dentin bonded with an etch-and-rinse adhesive and that in conjunction with chlorhexidine, an MMP inhibitor, applied after phosphoric-acid-etching. Contralateral pairs of bonded Class I restorations in primary molars of clinical subjects were retrieved after a six-month period of intra-oral functioning and processed for transmission electron microscopy. Hybrid layers from the chlorhexidine-treated teeth exhibited normal structural integrity of the collagen network. Conversely, abnormal hybrid layers were seen in the control teeth, with progressive disintegration of the fibrillar network, to the extent that it was beyond detection by collagen staining. Self-destruction of collagen matrices occurs rapidly in resin-infiltrated dentin in vivo and may be arrested with the use of chlorhexidine as an MMP inhibitor.

Journal ArticleDOI
28 Jul 2005-Nature
TL;DR: It is suggested that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.
Abstract: Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets 1,2 Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon 1 High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon 1‐3 , but little agreement exists about the sources or turnover times of this carbon 2,4,5 Here we present results of an extensive survey of the carbon isotope composition ( 13 C and 14 C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system We find that respiration of contemporary organic matter (less than five years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in medium to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics Riverine CO2 concentrations in Amazonian lowlands are 5–30 times supersaturated with respect to atmospheric equilibrium 1 ; such conditions may be prevalent throughout the humid tropics In situ respiration is the primary source of CO2 sustaining supersaturation in rivers, although inputs from groundwater supersaturated by soil respiration can be important in small systems and from submerged root respiration in floodplain-influenced systems 1–3,6–8 Although air–water gas exchange is a bi-directional process, atmospheric CO2 invasion has a negligible role compared to the large CO2 evasion fluxes, except at low supersaturation 2,3,6,7 13 C and 14 C isotopes can provide constraints on sources and turnover times of organic carbon fuelling river respiration, but no previous tropical study has used a dual-isotope approach to address these questions Studies in temperate eastern USA provide contrasting findings In the Hudson River, up to 70% of the centuries-old terrestrial organic carbon entering the river is respired in transit, and the average age of riverine organic carbon decreases downstream 2 However, the youngest components of dissolved organic carbon (DOC) are preferentially respired in the York River 5 , and modern dissolved inorganic carbon (DIC) in the Parker River may be explained by respiration of young DOC produced within the estuary 4 Documenting key patterns and controls on CO2 sources in diverse ecosystems is critical to advance our understanding of CO2 outgassing from rivers and its contribution to regional net carbon budgets To identify dominant sources and turnover times of riverine carbon throughout the Amazon basin, we analysed 14 C and 13 Co f

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TL;DR: Comparing the water sorption and modulus of elasticity of five experimental neat resins of increasing hydrophilicity, as ranked by their Hoy's solubility parameters and five commercial resins found all resins stored in water exhibited a time-dependent decrease in modulus that was proportional to their degree of water Sorption.

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TL;DR: In this paper, the results of analysis of "snapshot" spectra of 253 metal-poor halo stars −3.8 ≤ (Fe/H) ≤− 1.5 obtained in the HERES survey are presented.
Abstract: We present the results of analysis of "snapshot" spectra of 253 metal-poor halo stars −3.8 ≤ (Fe/H) ≤− 1.5 obtained in the HERES survey. The snapshot spectra have been obtained with VLT/UVES and have typically S /N ∼ 54 per pixel (ranging from 17 to 308), R ∼ 20 000, λ = 3760-4980 A. This sample represents the major part of the complete HERES sample of 373 stars; however, the CH strong content of the sample is not dealt with here. The spectra are analysed using an automated line profile analysis method based on the Spectroscopy Made Easy (SME) codes of Valenti & Piskunov. Elemental abundances of moderate precision (absolute rms errors of order 0.25 dex, relative rms errors of order 0.15 dex) have been obtained for 22 elements, C, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, and Eu, where detectable. Of these elements, 14 are usually detectable at the 3σ confidence level for our typical spectra. The remainder can be detected in the least metal-poor stars of the sample, spectra with higher than average S /N ,o r when the abundance is enhanced. Among the sample of 253 stars, disregarding four previously known comparison stars, we find 8 r-II stars and 35 r-I stars. The r-II stars, including the two previously known examples CS 22892-052 and CS 31082-001, are centred on a metallicity of (Fe/H) = −2.81, with a very small scatter, on the order of 0.16 dex. The r-I stars are found across practically the entire metallicity range of our sample. We also find three stars with strong enhancements of Eu which are s-process rich. A significant number of new very metal-poor stars are confirmed: 49 stars with (Fe/H) < −3 and 181 stars with −3 < (Fe/H) < −2. We find one star with (Fe/H) < −3.5. We find the scatter in the abundance ratios of Mg, Ca, Sc, Ti, Cr, Fe, Co, and Ni, with respect to Fe and Mg, to be similar to the estimated relative errors and thus the cosmic scatter to be small, perhaps even non-existent. The elements C, Sr, Y, Ba and Eu, and perhaps Zr, show scatter at (Fe/H) < −2.5 significantly larger than can be explained from the errors in the analysis, implying scatter which is cosmic in origin. Significant scatter is observed in abundance ratios between light and heavy neutron-capture elements at low metallicity and low levels of r-process enrichment.

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TL;DR: Padroes e tendencias da disponibilidade domiciliar de alimentos no Brasil sao consistentes com a importância crescente de doencas cronicas nao transmissiveis no perfil de morbi-mortalidade e com o aumento continuo da prevalencia da obesidade no Pais.
Abstract: OBJETIVO: Descrever a distribuicao da disponibilidade domiciliar de alimentos no Brasil em 2002-2003 e avaliar sua evolucao nas areas metropolitanas do Pais no periodo 1974-2003. METODOS: A principal base de dados do estudo e a Pesquisa de Orcamento Familiar de 2002-2003 realizada pelo Instituto Brasileiro de Geografia e Estatistica em 48.470 domicilios brasileiros. Em cada domicilio, num periodo de sete dias consecutivos, foram registradas todas as aquisicoes, monetarias ou nao monetarias, de alimentos e bebidas para consumo familiar. As quantidades de alimentos adquiridas foram transformadas em calorias e macronutrientes, usando tabelas de composicao alimentar. RESULTADOS: Caracteristicas positivas do padrao alimentar, encontradas em todas as regioes e em todas as classes de rendimento, foram a adequacao do teor proteico das dietas e o elevado aporte relativo de proteinas de alto valor biologico. Caracteristicas negativas, tambem disseminadas no Pais, foram excesso de acucar e presenca insuficiente de frutas e hortalicas na dieta. Nas regioes economicamente mais desenvolvidas, no meio urbano e entre familias com maior rendimento houve tambem excesso de gorduras em geral e de gorduras saturadas. A evolucao nas areas metropolitanas do Pais evidenciou declinio no consumo de alimentos basicos, como arroz e feijao, aumentos de ate 400% no consumo de produtos industrializados, como biscoitos e refrigerantes, persistencia do consumo excessivo de acucar e insuficiente de frutas e hortalicas e aumento no teor da dieta em gorduras em geral e gorduras saturadas. CONCLUSOES: Padroes e tendencias da disponibilidade domiciliar de alimentos no Brasil sao consistentes com a importância crescente de doencas cronicas nao transmissiveis no perfil de morbi-mortalidade e com o aumento continuo da prevalencia da obesidade no Pais.

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TL;DR: Results extend to mice the concept that the release of primary mediators responsible for hypernociception is preceded by a cascade of cytokines.
Abstract: The hypernociceptive effects of cytokines [TNF-α, keratinocyte-derived chemokine (KC), and IL-1β] and their participation in carrageenan (Cg)-induced inflammatory hypernociception in mice were investigated. Nociceptor sensitization (hypernociception) was quantified with an electronic version of the von Frey filament test in WT and TNF receptor type 1 knockout mice (TNF-R1–/–). TNF-α-induced hypernociception was abolished in TNF-R1–/– mice, partially inhibited by pretreatment with IL-1 receptor antagonist (IL-1ra) or indomethacin and unaffected by Ab against KC (AbKC) or guanethidine. IL-1ra and indomethacin pretreatment strongly inhibited the hypernociception induced by IL-1β, which was not altered by AbKC or guanethidine or by knocking out TNF-R1. KC-induced hypernociception was abolished by AbKC, inhibited by pretreatment with indomethacin plus guanethidine, and partially inhibited by IL-1ra, indomethacin, or guanethidine. In contrast, KC-induced hypernociception was not altered by knocking out TNF-R1. Cg-induced hypernociception was abolished by administration of indomethacin plus guanethidine, diminished in TNF-R1–/– mice, and partially inhibited in WT mice pretreated with AbKC, IL-1ra, indomethacin, or guanethidine. TNF-α, KC, and IL-1β concentrations were elevated in the skin of Cg-injected paws. The TNF-α and KC concentrations rose concomitantly and peaked before that of IL-1β. In mice, the cytokine cascade begins with the release of TNF-α (acting on TNF-R1 receptor) and KC, which stimulate the release of IL-1β. As in rats, the final mediators of this cascade were prostaglandins released by IL-1β and sympathetic amines released by KC. These results extend to mice the concept that the release of primary mediators responsible for hypernociception is preceded by a cascade of cytokines.

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TL;DR: Middle-aged patients with OSA who are free of overt cardiovascular diseases have early signs of atherosclerosis, and all vascular abnormalities correlated significantly with the severity of the OSA, which supports the hypothesis that OSA plays an independent role in Atherosclerosis progression.
Abstract: Background: Obstructive sleep apnea (OSA) is associated with several cardiovascular diseases. However, the mechanisms are not completely understood. Recent studies have shown that OSA is associated with multiple markers of endothelial damage. We hypothesized that OSA affects functional and structural properties of large arteries, contributing to atherosclerosis progression. Methods and Measurements: Twelve healthy volunteers, 15 patients with mild to moderate OSA, and 15 with severe OSA matched for age, sex, and body mass index were studied by using (1) full standard overnight polysomnography; (2) carotid-femoral pulse wave velocity with a noninvasive automatic device; and (3) a high-definition echo-tracking device to measure intima-media thickness, diameter, and distensibility. All participants were free of hypertension, diabetes, and smoking, and were not on any medications. Patients with OSA were naive to treatment. Main Results: Significant differences existed between control subjects and patients wit...