Função executiva e quociente intelectual nos pacientes com diagnóstico de esquizofrenia

A esquizofrenia tem despertado o interesse de muitos profissionais da saúde. É considerada uma síndrome clínica que afeta diversos processos, como o pensamento, a emoção, os movimentos, o comportamento; e processos cognitivos como a atenção, a memória, a linguagem e, especialmente, as funções executivas. O objetivo deste estudo foi avaliar as funções executivas nos pacientes com diagnóstico de esquizofrenia, para comprovar si há relação com o quociente intelectual. Intervieram 30 pacientes com escolaridade mínima de três anos, que estavam recebendo tratamento farmacológico, e no tinham evidência de atraso mental prévio. Aplicou-se o Wisconsin Card Sorting Tets (WCST) para avaliar as habilidades envolvidas na função executiva e a Escala de Inteligência de Weschler para adultos (WAIS) para determinar o quociente intelectual, o QI verbal, manipulador e global. Foi achado os pacientes apresentarem um deterioro global em cada uma das habilidades envolvidas na função executiva e situarem em um rango de deficiência mental na escala da inteligência. Isto confirma que mesmo se há deterioro das funções executivas e um nível baixo de quociente intelectual nos pacientes, não existe correlação entre estas duas variáveis.La esquizofrenia ha generado el interés de muchos profesionales de la salud, considerada desde un principio como un síndrome clínico que afecta diferentes procesos como el pensamiento, la emoción, los movimientos, el comportamiento, y aspectos cognitivos como la atención, la memoria, el lenguaje y especialmente las funciones ejecutivas. El objetivo del presente estudio fue evaluar las funciones ejecutivas en pacientes con diagnóstico de esquizofrenia para verificar si existe alguna relación con el Cociente Intelectual. Se tomaron 30 pacientes con un mínimo de escolaridad de tres años, que se encontraban recibiendo tratamiento farmacológico y sin evidencia de un retardo mental previo; se les aplicó el Wisconsin Card Sorting Test (WCST) para evaluar las habilidades implicadas en la función ejecutiva y la escala de Inteligencia de Weschler para adultos (WAIS) para determinar el Cociente Intelectual, CI verbal, manipulativo y global. En la población estudiada, se encontró que los pacientes presentaron un deterioro global en cada una de las habilidades implicadas en la función ejecutiva, y se ubicaron en un rango de deficiencia mental en la escala de inteligencia, confirmándose que aunque existe deterioro de las funciones ejecutivas y un nivel de cociente intelectual bajo en los pacientes, no existe correlación entre estas dos variables.Schizophrenia, considered from the beginning as a clinical syndrome that affects different processes such as thinking, emotions, movements, and behaviour, as well as cognitive aspects such as attention, memory, language and especially the executive functions, is an entity that has arisen the interest of many health professionals. The objective of the present study was to assess the above mentioned functions in patients who had been diagnosed with schizophrenia and later verify if there was a relation with their intellectual quotient. The sample for this research was composed of 30 patients with no evidence of previous mental retardation, who had studied for at least three years and who were receiving the suitable pharmacological treatment. The Wisconsin Card Sorting Test (WCST) was administered to assess the abilities involved in the executive function, and the Weschler Adult Intelligence Scale (WAIS), to determine the verbal, manipulative and global intellectual quotient (IQ). The research results showed that the patients presented a global deterioration in each one of the abilities involved in the executive function and were located within the rank of mental deficiency in the intelligence scale, thus confirming that although patients showed deterioration of the executive functions and a low level of intellectual quotient, there is no correlation between these two variables

Analysis of Volatile Organic Compounds in the Apollo Next Generation Sample Analysis (ANGSA) 73002 Core Sample

Understanding the organic content of lunar regolith was an early priority upon the return of Apollo samples, with amino acids being of special interest because of their importance to life on Earth and their astrobiological relevance. Many initial studies focused on the detection of amino acids in these samples and attempts to determine the origin of those compounds. Although no consensus on the origin of the amino acids was reached in those early studies, more recent work determined that the detected amino acids originated from both terrestrial contamination and meteoritic or cometary in fall to the lunar surface. A majority of the amino acids in the Apollo samples studied originated from precursor molecules, either indigenous to the lunar samples or contaminants, that reacted during the water extraction and acid hydrolysis process for analysis in the laboratory, but the identities of the amino acid precursors still remain poorly understood. Such precursors could include hydrogen cyanide (HCN) and other volatile organic compounds such as amines, carboxylic acids, or aldehydes and ketones. The identities of these compounds, as well as the effects of years of curation on their abundances in lunar regolith samples stored at ambient temperature under nitrogen gas purge, are not clear. The specially curated samples available through the Apollo Next Generation Sample Analysis (ANGSA) program provide a unique opportunity to use state-of- the-art analytical techniques to examine previously unstudied lunar materials. The ANGSA samples include three types of samples: 1) samples stored frozen since <1 month after Earth arrival; 2) samples stored under helium; and 3) a double drive tube collected by Apollo 17 astronauts, with the bottom portion of the drive tube sealed under vacuum on the Moon and never opened. In contrast to the typically curated Apollo samples that have been kept for decades at room temperature under flowing nitrogen purge that may have significantly reduced the abundance of volatiles, the vacuum-sealed and frozen samples may have enhanced preservation of these volatiles. Our initial investigation examines amino acids and their potential volatile precursors, including hydrogen cyanide (HCN), aldehydes, ketones, amines, and mono-carboxylic acids, in a sample from the top portion of the Apollo 17 double drive tube. These results will aid in understanding the lunar abundances of these molecules and will also be compared to future analyses of other drive tube and frozen ANGSA samples

The incidence of clinical malaria detected by active case detection in children in Ifakara, southern Tanzania

Between July 2000 and June 2001, we used weekly active case detection (ACD) of clinical malaria episodes in 618 children aged <5 years to describe the epidemiology of malaria in Ifakara, southern Tanzania. Plasmodium falciparum-positive blood slides prepared from children with axillary temperature ⩾ 37.5°C were used to define clinical malaria and a rolling cross-sectional survey documented the prevalences of parasitaemia and anaemia. A random subsample of children was visited daily for 1 month at the end of the study to assess the effect of more frequent visits on estimated incidence rates. Only 50 (8%) children had 1 or more episodes of clinical malaria during the year, an overall incidence of 0.275 episodes/100 child-weeks-at-risk, with no age dependence. The maximum parasite prevalence of 25% was reached in children aged 4 years. The incidence of illness was significantly lower in children visited daily than in those visited weekly., suggesting a marked effect of frequent visits on estimated incidence rates. We conclude that the age pattern of malaria detected through ACD is a more robust epidemiological indicator than absolute incidence rate estimates and that, in contrast to the surrounding area, Ifakara town is subject to only moderate perennial malaria transmissio

Nonequilibrium effects in superconducting necks of nanoscopic dimensions

We have fabricated superconducting connecting necks of Pb with a scanning tunneling microscope (STM) and studied their properties under magnetic fields near the transition to the resistive state. A striking phenomenology is found with two well defined conduction regimes as a function of the magnetic field. We discuss the possible origin of this behavior in terms of the interplay between the field dependence of the quasiparticle charge imbalance length $\Lambda_{Q*}$ and the length of the neck which is superconducting under field.Comment: 11 pages, 3 figures; to be published in Physics Letters

Directed paths on hierarchical lattices with random sign weights

We study sums of directed paths on a hierarchical lattice where each bond has either a positive or negative sign with a probability $p$. Such path sums $J$ have been used to model interference effects by hopping electrons in the strongly localized regime. The advantage of hierarchical lattices is that they include path crossings, ignored by mean field approaches, while still permitting analytical treatment. Here, we perform a scaling analysis of the controversial ``sign transition'' using Monte Carlo sampling, and conclude that the transition exists and is second order. Furthermore, we make use of exact moment recursion relations to find that the moments always determine, uniquely, the probability distribution $P(J)$. We also derive, exactly, the moment behavior as a function of $p$ in the thermodynamic limit. Extrapolations ($n\to 0$) to obtain for odd and even moments yield a new signal for the transition that coincides with Monte Carlo simulations. Analysis of high moments yield interesting ``solitonic'' structures that propagate as a function of $p$. Finally, we derive the exact probability distribution for path sums $J$ up to length L=64 for all sign probabilities.Comment: 20 pages, 12 figure

Electrophysiological Heterogeneity of Fast-Spiking Interneurons: Chandelier versus Basket Cells

In the prefrontal cortex, parvalbumin-positive inhibitory neurons play a prominent role in the neural circuitry that subserves working memory, and alterations in these neurons contribute to the pathophysiology of schizophrenia. Two morphologically distinct classes of parvalbumin neurons that target the perisomatic region of pyramidal neurons, chandelier cells (ChCs) and basket cells (BCs), are generally thought to have the same "fast-spiking" phenotype, which is characterized by a short action potential and high frequency firing without adaptation. However, findings from studies in different species suggest that certain electrophysiological membrane properties might differ between these two cell classes. In this study, we assessed the physiological heterogeneity of fast-spiking interneurons as a function of two factors: species (macaque monkey vs. rat) and morphology (chandelier vs. basket). We showed previously that electrophysiological membrane properties of BCs differ between these two species. Here, for the first time, we report differences in ChCs membrane properties between monkey and rat. We also found that a number of membrane properties differentiate ChCs from BCs. Some of these differences were species-independent (e.g., fast and medium afterhyperpolarization, firing frequency, and depolarizing sag), whereas the differences in the first spike latency between ChCs and BCs were species-specific. Our findings indicate that different combinations of electrophysiological membrane properties distinguish ChCs from BCs in rodents and primates. Such electrophysiological differences between ChCs and BCs likely contribute to their distinctive roles in cortical circuitry in each species. © 2013 Povysheva et al

Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by ^1H molecular diffusion NMR and ^(19)F spin diffusion NMR

R_f-PEG (fluoroalkyl double-ended poly(ethylene glycol)) hydrogel is potentially useful as a drug delivery depot due to its advanced properties of sol–gel two-phase coexistence and low surface erosion. In this study, ^1H molecular diffusion nuclear magnetic resonance (NMR) and ^(19)F spin diffusion NMR were used to probe the drug loading and diffusion properties of the R_f-PEG hydrogel for small anticancer drugs, 5-fluorouracil (FU) and its hydrophobic analog, 1,3-dimethyl-5-fluorouracil (DMFU). It was found that FU has a larger apparent diffusion coefficient than that of DMFU, and the diffusion of the latter was more hindered. The result of ^(19)F spin diffusion NMR for the corresponding freeze-dried samples indicates that a larger portion of DMFU resided in the R_f core/IPDU intermediate-layer region (where IPDU refers to isophorone diurethane, as a linker to interconnect the R_f group and the PEG chain) than that of FU while the opposite is true in the PEG–water phase. To understand the experimental data, a diffusion model was proposed to include: (1) hindered diffusion of the drug molecules in the R_f core/IPDU-intermediate-layer region; (2) relatively free diffusion of the drug molecules in the PEG-water phase (or region); and (3) diffusive exchange of the probe molecules between the above two regions. This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications

Anaemia in hospitalised preschool children from a rural area in Mozambique: a case control study in search for aetiological agents

Background: Young children bear the world’s highest prevalence of anaemia, the majority of which is of multifactorial aetiology, which in turn hampers its successful prevention. Even moderate degrees of anaemia are associated with increased mortality and morbidity. Despite this evidence, there is a lack of effective preventive programs and absence of consensus in the safety of iron supplementation in malaria areas, which reflects the poor understanding of the contribution of different aetiologies to anaemia. In order to reduce the anaemia burden in the most vulnerable population, a study to determine the aetiology of anaemia among pre-school Mozambican children was performed. Methods: We undertook a case–control study of 443 preschool hospitalized children with anaemia (haemoglobin concentration <11 g/dl) and 289 community controls without anaemia. Inclusion criteria were: age 1–59 months, no blood transfusion in the previous month, residence in the study area and signed informed consent. Both univariable and multivariable logistic regression analyses were performed to identify factors associated with anaemia and adjusted attributable fractions (AAF) were estimated when appropriate. Results: Malaria (adjusted odds ratio (AOR) = 8.39, p < 0.0001; AAF = 37%), underweight (AOR = 8.10, p < 0.0001; AAF = 43%), prealbumin deficiency (AOR = 7.11, p < 0.0001; AAF = 77%), albumin deficiency (AOR = 4.29, p = 0.0012; AAF = 30%), HIV (AOR = 5.73, p = 0.0060; AAF = 18%), and iron deficiency (AOR = 4.05, p < 0.0001; AAF = 53%) were associated with anaemia. Vitamin A deficiency and α-thalassaemia were frequent (69% and 64%, respectively in cases) but not independently related to anaemia. Bacteraemia (odds ratio (OR) = 8.49, p = 0.004), Parvovirus-B19 (OR = 6.05, p = 0.017) and Epstein-Barr virus (OR = 2.10, p = 0.0015) infections were related to anaemia only in the unadjusted analysis. Neither vitamin B12 deficiency nor intestinal parasites were associated with anaemia. Folate deficiency was not observed. Conclusions: Undernutrition, iron deficiency, malaria, and HIV are main factors related to anaemia in hospitalised Mozambican preschool children. Effective programs and strategies for the prevention and management of these conditions need to be reinforced. Specifically, prevention of iron deficiency that accounted in this study for more than half of anaemia cases would have a high impact in reducing the burden of anaemia in children living under similar conditions. However this deficiency, a common preventable and treatable condition, remains neglected by the international public health community

Fallas del estado, violencia y comercio: rutas comerciales peligrosas en Colombia

En este documento se investiga el efecto de la violencia armada doméstica provocada por la inestabilidad política sobre las fricciones de la distancia en la movilidad de carga. Además, el efecto de esas fricciones sobre el acceso diferencial de las regiones a los mercados globales. Se concluye que el sistema de transporte colombiano se ve obstaculizado por deficiencias en la infraestructura e instituciones de transporte terrestre y por entornos políticos fragmentados. El análisis a nivel micro de los registros de exportaciones hacia Estados Unidos corrobora que el envío de carga de exportación desde las regiones del interior se redirige para evitar exposiciones a la violencia armada doméstica a pesar de las amplias distancias de envío marítimo y terrestre existentes. Aprovechamos las trayectorias del transporte de carga desde las regiones colombianas y los patrones espaciales de los conflictos armados violentos para ver cómo los entornos geopolíticos inestables son perjudiciales para la movilidad del transporte de carga y la apertura del mercado. A través de un modelo de elección discreta se muestra que el flujo de envío se ve frenado por el desvío debido a la violencia armada doméstica y que las regiones del interior tienen acceso restringido al mercado global. La percepción de riesgo y comportamiento de redireccionamiento se considera heterogénea entre los envíos y está condicionada a las características del envío, como el tipo de mercancía, el tamaño y el valor del flete. Los resultados resaltan que el conseguir la estabilidad política puede ayudar a mejorar la movilidad de carga y el desarrollo económico orientado a la exportación en el Sur globalWe investigate the effect of domestic armed violence brought about by political instability on the geography of distance frictions in freight mobility and the resulting differential access of regions to global markets. The Colombian transportation system has been found to be impeded by deficiencies in landside transport infrastructure and institutions, and by fragmented political environments. The micro-level analysis of U.S.-bounded export shipping records corroborates that export freight shipping from inland regions is re-routed to avoid exposures to domestic armed violence despite greatly extended landside and maritime shipping distances. We exploit the trajectories of freight shipping from Colombian regions and spatial patterns of violent armed conflicts to see how unstable geopolitical environments are detrimental to freight shipping mobility and market openness. The discrete choice model shows that the shipping flow is greatly curbed by the extended re-routing due to domestic armed violence and that inland regions have restricted access to the global market. The perception of risk and re-routing behavior is found heterogeneous across shipments and conditional to shipment characteristics, such as commodity type, freight value and shipper sizes. The results highlight that political stability must be accommodated for improved freight mobility and export-oriented economic development in the global South.Fallas del estado, violencia y comercio: Rutas comerciales peligrosas en Colombia Enfoque En este artículo se investiga cómo el efecto la violencia armada, que surge en medio de entornos geopolíticos inestables, es perjudicial para la movilidad de carga y el acceso de las regiones a las cadenas globales de logística de mercancías. Nuestro análisis se centra en el caso de Colombia en 2006-2007, por ser un periodo que estuvo muy permeado por la violencia y delincuencia, en muchas de las rutas principales de transporte al interior del país. El objetivo es determinar cómo la inseguridad durante este período de tiempo actuó como un impedimento para el movimiento del transporte marítimo de carga en el comercio internacional, actuando como otros de sus determinantes, tales como los factores arancelarios y no arancelarios. De esta manera, se propone la hipótesis de que los encargados de la logística del transporte buscarían reducir su exposición a conflictos armados domésticos a lo largo de las rutas, desplazándose a puertos más lejanos, a los que se pueda acceder de manera más segura, pese a tener que opotar por distancias de envío más extendidas. Para este efecto, este trabajo explota la existencia de registros de embarque proveniente de las bases de datos de Port Import Export Reporting Services y los datos georreferenciados de conflictos armados nacionales de Uppsala Conflict Data Program. Contribución La visión tradicional en la literatura comercial se ha concentrado en cómo el efecto de los aranceles, las cuotas, el acceso al mar, las fronteras internacionales o la calidad de la infraestructura logística limitan las actividades de exportación y el comercio internacional. Nuestra principal contribución a la discusión está relacionada con los efectos que puede tener la inseguridad como otro impedimento importante para el cruce de fronteras de mercancías. Específicamente, calculamos las equivalencias en distancia del riesgo observado de conflictos armados internos para medir el costo del cambio de ruta y evaluamos hasta qué punto estos restringen el acceso a los mercados globales. Conclusiones Encontramos evidencia sobre Colombia, centrados en el período 2006-2007, de que el riesgo de violencia a lo largo de las rutas de transporte marítimo terrestre resulta en una geografía de la movilidad de carga alterada, con rutas de envío más riesgosas a los puertos que se evitan, en favor de otras opciones más seguras. Los transportistas cambiarían una ruta más corta, pero más riesgosa, por una ruta más segura a puertos ubicados más lejos del origen del envío. Además, estarían dispuestos a tomar la ruta de envío terrestre a puertos donde haya mayor seguridad, incluso en el caso en que el segmento marítimo de la distancia de envío, asociada al puerto de entrada de los Estados Unidos, sea más extenso. Nuestro estudio plantea que la falta de control de la violencia armada a lo largo de las rutas comerciales impide extensamente el transporte de carga, aumenta el costo de hacer negocios y limita en gran medida el acceso al mercado global, lo que podría desalentar las actividades económicas orientadas a la exportación. Frase destacada: Nuestro estudio plantea que la falta de control de la violencia armada a lo largo de las rutas comerciales impide extensamente el transporte de carga, aumenta el costo de hacer negocios y limita el acceso al mercado global, lo que podría desalentar las actividades económicas orientadas a la exportación

Forest carbon sequestration:the impact of forest management

In this chapter, we describe alternative ways in which forests and forestry can help to mítigate climate change, along with the potential impact of these activities. The three carbon storage compartments should be considered inall impact estimates. Carbon content in living biomass is easily estimated via species-specific equations or by applying factors to oven-dry biomass weights (e.g.,lbañez et al.,2002, Herrero et al.,2011,Castaño and Bravo, 2012).Litter carbon content has been analysed in many studies on primary forest productivity, though information regarding the influence of forest management on litter carbon content is less abundant (Blanco et al., 2006). In the last decade,efforts have been made to assess soil carbon in forests, but studies on the effect of forest management on soils show discrepancies (Lindner and Karjalainen,2007).Hoover (2011), for example,found no difference in forest floor carbon stocks among stands subjected to partial or complete harvest treatments in the United States.Instituto Universitario de Gestión Forestal Sostenibl