709 research outputs found
Does crime affect economic decisions? An empirical investigation of savings in a high-crime environment
While most economic studies of crime have focused on its determinants, we study the reverse question: does crime affect economic behavior? Being such an important social phenomenon, one would expect crime to affect economic decisions. Using local data on crime rates and savings per capita in a high-crime environment, we document a striking empirical relationship: crime induces savings. Our paper is one of the first to successfully relate crime to an economic outcome. This result is robust to an extensive sensitivity analysis, which include: 1) controlling to a large set of demographic covariates; 2) accounting for the fact that crime and savings may be determined jointly; 3) measuring savings in different ways; 4) accounting for the presence of possible outliers; 5) weighting the data according to population; 6) accounting for spatial correlation; and, finally, 7) estimating the model for different sub-samples of cities. Our estimates indicate that only property, not violent, crime induces savings, which is consistent with the theoretical explanations on why crime would increase thriftinessCrime, Economic Behavior, Savings
Diferenças nos padrões de consumo de álcool entre homens e mulheres no Brasil
OBJECTIVE: To examine sex differences in alcohol consumption according to age groups, and to assess gender and age effects on several aspects of alcohol consumption patterns. METHOD: Based on a Brazilian nationwide representative sample (n = 3,007), we analysed the differences in drinking patterns between genders. We also assessed the effects of gender, age, and gender by age interaction for alcohol consumption dimensions (frequent drinking, usual intake, binge drinking, and frequent binge drinking), using logistic and negative binomial regression models. RESULTS: Gender, age, and gender by age interaction had significant effects on the predictive models for all studied drinking patterns, except for the 'usual' dosage. The effect of gender on drinking patterns varies with age. While gender has a greater effect in older age groups, the difference between men and women decreased in the younger age groups. CONCLUSIONS: Gender convergence regarding alcohol use is a trend that might be influenced by environmental factors and should be addressed in prevention and treatment programs, as well as in public health policies.OBJETIVO: Avaliar as diferenças nos padrões de consumo de álcool entre os gêneros de acordo com as faixas etárias e avaliar os efeitos do gênero e da idade em diversos aspectos do padrão de consumo de bebidas alcoólicas. MÉTODO: Com base em amostra representativa da população brasileira (n = 3.007), nós avaliamos as diferenças nos padrões de consumo de álcool entre os gêneros. Nós também avaliamos os efeitos do gênero, da idade e da interação entre gênero e idade nas dimensões do consumo de álcool (consumo frequente, dose usual, consumo em binge e consumo frequente em binge), com uso de modelos de regressão logística e regressão binomial negativa. RESULTADOS: O gênero, a idade e a interação entre gênero e idade tiveram efeitos significantes nos modelos preditivos para todos os padrões de consumo estudados, com exceção da dose usual. O efeito do gênero ao longo das faixas etárias varia com a idade. Enquanto o gênero teve um efeito maior nas faixas etárias mais velhas, a diferença entre homens e mulheres diminuiu nas faixas etárias mais novas. CONCLUSÕES: A convergência entre os gêneros no que se refere ao uso de álcool é uma tendência que pode ser influenciada por fatores ambientais e deveria ser focada nos programas de prevenção e tratamento assim como nas políticas públicas.Universidade Federal de São Paulo (UNIFESP) Department of PsychiatryIpsos ReidUniversidade de São Paulo School of Medicine Department of PsychiatryUniversity of Texas School of Public HealthUniversidade Federal de Santa Catarina Department of PsychiatryUNIFESP, Department of PsychiatrySciEL
Fire retardant action of mineral fillers
Endothermically decomposing mineral fillers, such as aluminium or magnesium hydroxide, magnesium carbonate, or mixed magnesium/calcium carbonates and hydroxides, such as
naturally occurring mixtures of huntite and hydromagnesite are in heavy demand as sustainable, environmentally benign fire retardants. They are more difficult to deploy than the
halogenated flame retardants they are replacing, as their modes of action are more complex, and are not equally effective in different polymers. In addition to their presence (at levels up to 70%), reducing the flammable content of the material, they have three quantifiable fire
retardant effects: heat absorption through endothermic decomposition; increased heat capacity of the polymer residue; increased heat capacity of the gas phase through the presence of water or carbon dioxide. These three contributions have been quantified for eight of the most common fire retardant mineral fillers, and the effects on standard fire tests such as the LOI, UL 94 and cone calorimeter discussed. By quantifying these estimable
contributions, more subtle effects, which they might otherwise mask, may be identified
Collecting system percutaneous access using real-time tracking sensors : first pig model in vivo experience
PURPOSE:
Precise needle puncture of the renal collecting system is an essential but challenging step for successful percutaneous nephrolithotomy. We evaluated the efficiency of a new real-time electromagnetic tracking system for in vivo kidney puncture.
MATERIALS AND METHODS:
Six anesthetized female pigs underwent ureterorenoscopy to place a catheter with an electromagnetic tracking sensor into the desired puncture site and ascertain puncture success. A tracked needle with a similar electromagnetic tracking sensor was subsequently navigated into the sensor in the catheter. Four punctures were performed by each of 2 surgeons in each pig, including 1 each in the kidney, middle ureter, and right and left sides. Outcome measurements were the number of attempts and the time needed to evaluate the virtual trajectory and perform percutaneous puncture.
RESULTS:
A total of 24 punctures were easily performed without complication. Surgeons required more time to evaluate the trajectory during ureteral than kidney puncture (median 15 seconds, range 14 to 18 vs 13, range 11 to 16, p=0.1). Median renal and ureteral puncture time was 19 (range 14 to 45) and 51 seconds (range 45 to 67), respectively (p=0.003). Two attempts were needed to achieve a successful ureteral puncture. The technique requires the presence of a renal stone for testing.
CONCLUSIONS:
The proposed electromagnetic tracking solution for renal collecting system puncture proved to be highly accurate, simple and quick. This method might represent a paradigm shift in percutaneous kidney access techniques.Supported by the Foundation for Science and Technology-Portugal Fellowships SFRH/BD/ 74276/2010 and SFRH/BPD/46851/2008, and Foundation for Science and Technology-Portugal Research and Development Projects PTDC/SAUBEB/ 103368/2008 and PTDC/SAU-OSM/105578/2008 FCOMP-01-0124-FEDER-011363
Molecular Evolution of Multiple Arylalkylamine N-Acetyltransferase (AANAT) in Fish
Arylalkylamine N-acetyltransferase (AANAT) catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to arylalkylamines, including indolethylamines and phenylethylamines. Multiple aanats are present in teleost fish as a result of whole genome and gene duplications. Fish aanat1a and aanat2 paralogs display different patterns of tissue expression and encode proteins with different substrate preference: AANAT1a is expressed in the retina, and acetylates both indolethylamines and phenylethylamines; while AANAT2 is expressed in the pineal gland, and preferentially acetylates indolethylamines. The two enzymes are therefore thought to serve different roles. Here, the molecular changes that led to their specialization were studied by investigating the structure-function relationships of AANATs in the gilthead seabream (sb, Sperus aurata). Acetylation activity of reciprocal mutated enzymes pointed to specific residues that contribute to substrate specificity of the enzymes. Inhibition tests followed by complementary analyses of the predicted three-dimensional models of the enzymes, suggested that both phenylethylamines and indolethylamines bind to the catalytic pocket of both enzymes. These results suggest that substrate selectivity of AANAT1a and AANAT2 is determined by the positioning of the substrate within the catalytic pocket, and its accessibility to catalysis. This illustrates the evolutionary process by which enzymes encoded by duplicated genes acquire different activities and play different biological roles
Gene expression profile of HIV-1 Tat expressing cells: a close interplay between proliferative and differentiation signals
BACKGROUND: Expression profiling holds great promise for rapid host genome functional analysis. It is plausible that host expression profiling in an infection could serve as a universal phenotype in virally infected cells. Here, we describe the effect of one of the most critical viral activators, Tat, in HIV-1 infected and Tat expressing cells. We utilized microarray analysis from uninfected, latently HIV-1 infected cells, as well as cells that express Tat, to decipher some of the cellular changes associated with this viral activator. RESULTS: Utilizing uninfected, HIV-1 latently infected cells, and Tat expressing cells, we observed that most of the cellular host genes in Tat expressing cells were down-regulated. The down-regulation in Tat expressing cells is most apparent on cellular receptors that have intrinsic receptor tyrosine kinase (RTK) activity and signal transduction members that mediate RTK function, including Ras-Raf-MEK pathway. Co-activators of transcription, such as p300/CBP and SRC-1, which mediate gene expression related to hormone receptor genes, were also found to be down-regulated. Down-regulation of receptors may allow latent HIV-1 infected cells to either hide from the immune system or avoid extracellular differentiation signals. Some of the genes that were up-regulated included co-receptors for HIV-1 entry, translation machinery, and cell cycle regulatory proteins. CONCLUSIONS: We have demonstrated, through a microarray approach, that HIV-1 Tat is able to regulate many cellular genes that are involved in cell signaling, translation and ultimately control the host proliferative and differentiation signals
Chromatin and siRNA pathways cooperate to maintain DNA methylation of small transposable elements in Arabidopsis
BACKGROUND: DNA methylation occurs at preferred sites in eukaryotes. In Arabidopsis, DNA cytosine methylation is maintained by three subfamilies of methyltransferases with distinct substrate specificities and different modes of action. Targeting of cytosine methylation at selected loci has been found to sometimes involve histone H3 methylation and small interfering (si)RNAs. However, the relationship between different cytosine methylation pathways and their preferred targets is not known. RESULTS: We used a microarray-based profiling method to explore the involvement of Arabidopsis CMT3 and DRM DNA methyltransferases, a histone H3 lysine-9 methyltransferase (KYP) and an Argonaute-related siRNA silencing component (AGO4) in methylating target loci. We found that KYP targets are also CMT3 targets, suggesting that histone methylation maintains CNG methylation genome-wide. CMT3 and KYP targets show similar proximal distributions that correspond to the overall distribution of transposable elements of all types, whereas DRM targets are distributed more distally along the chromosome. We find an inverse relationship between element size and loss of methylation in ago4 and drm mutants. CONCLUSION: We conclude that the targets of both DNA methylation and histone H3K9 methylation pathways are transposable elements genome-wide, irrespective of element type and position. Our findings also suggest that RNA-directed DNA methylation is required to silence isolated elements that may be too small to be maintained in a silent state by a chromatin-based mechanism alone. Thus, parallel pathways would be needed to maintain silencing of transposable elements
Control de la hipertensión arterial por especialistas en Argentina (estudio charter)
Introducción: La proporción de hipertensos medicados que presentan adecuado control de su HTA es muy baja a nivel mundial, del orden del 32,5%. Objetivos: 1)determinar el grado de control de la HTA en hipertensos medicados, tratados en centros especializados de la República Argentina; 2) caracterizar a los pacientes atendidos en dichos centros respecto de su perfil de riesgo cardiovascular; analizar el número y tipo de antihipertensivos utilizados; determinar los factores asociados a un adecuado control de la presión arterial(PA). Metodología: estudio de corte transversal, en el que se incluyeron mayores de 18 años con diagnóstico establecido de hipertensión arterial, bajo tratamiento farmacológico, provenientes de 10 centros de referencia en HTA de la Argentina. En una única visita se midió la PA [3 lecturas] y se registraron variables antropométricas y demográficas, así como las características del tratamiento antihipertensivo. Se consideró adecuado control de la PA en consultorio a un promedio por debajo de 140/90 mmHg en 80 años. Se estimó el porcentaje del grado de control de la PA con su IC95% y se determinaron las variables independientemente asociadas con el adecuado control de la PA a través de un análisis de regresión logística multivariable. Resultados: se incluyeron 1146 pacientes. El promedio de edad fue de 63,5 (13,1) años, 42,8% varones, 19,7% diabéticos, 8,3% tabaquistas, 67,4% dislipidémicos, 8,1% con antecedentes de enfermedad coronaria y 6,7% con antecedentes de enfermedad cerebrovascular. La media de PA en consultorio fue de 135,3 (14,8)/ 80,8 (10) mmHg, siendo el porcentaje de adecuado control de la PA de 64,8% (IC95%: 62-67,6%). El consumo promedio de antihipertensivos fue de 2,1 (1) drogas por paciente (Figura 1). En la Tabla 1 se muestran las características de los sujetos con adecuado vs. inadecuado control de la PA. En el análisis multivariable, sólo el sexo femenino fue un predictor independiente de adecuado control (OR 1,33 [IC95% 1,02-1,72],p=0,04). Conclusiones: un 65% de los pacientes hipertensos tratados en centros especializados de la Argentina presentan adecuado control de PA, siendo esta cifra muy superior a la reportada en población general. Futuros estudios deberán definir estrategias para optimizar el control en centros no especializados.Fil: Marin, Marcos. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Barochiner, Jessica. Instituto Universidad Escuela de Medicina del Hospital Italiano; ArgentinaFil: Rodriguez, Pablo. Instituto Cardiovascular de Buenos Aires; ArgentinaFil: Renna, Nicolas Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Cátedra de Fisiología Patológica; ArgentinaFil: Castellaro, Carlos. Sociedad Argentina de Hipertensión Arterial; ArgentinaFil: Espeche, Walter. Universidad Nacional de La Plata; ArgentinaFil: De Cerchio, Alejandro. Sociedad Argentina de Hipertensión Arterial; ArgentinaFil: Del Sueldo, Mildren. Sociedad Argentina de Hipertensión Arterial; ArgentinaFil: Visani, Sergio. Sociedad Argentina de Hipertensión Arterial; ArgentinaFil: Zilberman, Judith. Sociedad Argentina de Hipertensión Arterial; ArgentinaXXVI Congreso Argentino de Hipertensión ArterialMar del PlataArgentinaSociedad Argentina de Hipertensión Arteria
Genomic mapping of 5-hydroxymethylcytosine in the human brain
Methylation at the 5-position of cytosine is a well-studied epigenetic pathway. In addition to 5-methylcytosine (5mC), substantial amounts of 5-hydroxymethylcytosine (5hmC) also referred to as the sixth DNA base have been detected in certain tissues, most notably the brain. However, the genomic distribution of this cytosine modification is unknown. Here, we have used an immunoprecipitation technique (5hmC-IP) to examine the occurrence of 5hmC in DNA from human brain frontal lobe tissue. The distribution of 5hmC was compared to that of 5mC. We show that 5hmC is more selectively targeted to genes than is 5mC. 5hmC is particularly enriched at promoters and in intragenic regions (gene bodies) but is largely absent from non-gene regions. 5hmC peaks at transcription start sites did not correlate with gene expression levels for promoters with intermediate or high CpG content. However, the presence of 5hmC in gene bodies was more positively correlated with gene expression levels than was the presence of 5mC. Promoters of testis-specific genes showed strong 5mC peaks in brain DNA but were almost completely devoid of 5hmC. Our data provide an overview of the genomic distribution of 5hmC in human brain and will set the stage for further functional characterization of this novel DNA modification
A native chromatin purification system for epigenomic profiling in Caenorhabditis elegans
High-resolution mapping of chromatin features has emerged as an important strategy for understanding gene regulation and epigenetic inheritance. We describe an in vivo tagging system coupled to chromatin purification for genome-wide epigenetic profiling in Caenorhabditis elegans. In this system, we coexpressed the Escherichia coli biotin ligase enzyme (BirA), together with the C. elegans H3.3 gene fused to BioTag, a 23-amino-acid peptide serving as a biotinylation substrate for BirA, in vivo in worms. We found that the fusion BioTag::H3.3 was efficiently biotinylated in vivo. We developed methods to isolate chromatin under different salt extraction conditions, followed by affinity purification of biotinylated chromatin with streptavidin and genome-wide profiling with microarrays. We found that embryonic chromatin is differentially extracted with increasing salt concentrations. Interestingly, chromatin that remains insoluble after washing in 600 mM salt is enriched at 5′ and 3′ ends, suggesting the presence of large protein complexes that render chromatin insoluble at transcriptional initiation and termination sites. We also found that H3.3 landscapes from these salt fractions display consistent features that correlate with gene activity: the most highly expressed genes contain the most H3.3. This versatile two-component approach has the potential of facilitating genome-wide chromatin dynamics and regulatory site identification in C. elegans
- …