West Nile virus; ecology and epidemiology of an emerging pathogen in Colombia

El virus del oeste del Nilo (VON) es mantenido en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Los principales vectores son los mosquitos del genero Culex. Las aves son los huéspedes amplificadores primarios. Humanos y caballos son huéspedes incidentales finales. En humanos las infecciones por VON se presentan como enfermedad febril autolimitada. En los casos de enfermedad neurológica se puede presentar encefalitis, meningitis o meningoencefalitis, con mayor incidencia y mortalidad por encefalitis en personas de mayor edad y pacientes inmunocomprometidos. Se han reportado brotes en África, Medio Oriente, Europa y Asia. El virus apareció por primera vez en Estados Unidos en 1999 y se ha documentado su circulación en México, Islas Caimán, Jamaica, Republica Dominicana, Martinica, Guadalupe, Cuba, Puerto Rico, El Salvador y recientemente Colombia. La importancia en salud pública de VON si es introducido en áreas de Centro y Sur América dependerá del resultado de la interacción de múltiples factores. Colombia reúne las condiciones que favorecen su entrada y desarrollo. Se pueden postular dos hipótesis: el virus podría llegar a ser enzoótico y endémico y causar limitada enfermedad humana, o podría llegar a ser epidémico y causar brotes anuales que afecten humanos y animales. Esto dependerá de la susceptibilidad de las especies aviares colombianas al virus por las diferencias en su biología, y a las variaciones geográficas intraespecificas en la competencia de las diferentes especies de mosquito y los efectos de las condiciones medioambientales sobre su habilidad para transmitir el virus, y estos factores son determinantes en el ciclo de amplificación primario

Visual scoping operations for physical assembly

Planning is hard. The use of subgoals can make planning more tractable, but selecting these subgoals is computationally costly. What algorithms might enable us to reap the benefits of planning using subgoals while minimizing the computational overhead of selecting them? We propose visual scoping, a strategy that interleaves planning and acting by alternately defining a spatial region as the next subgoal and selecting actions to achieve it. We evaluated our visual scoping algorithm on a variety of physical assembly problems against two baselines: planning all subgoals in advance and planning without subgoals. We found that visual scoping achieves comparable task performance to the subgoal planner while requiring only a fraction of the total computational cost. Together, these results contribute to our understanding of how humans might make efficient use of cognitive resources to solve complex planning problems

Biomimetic Based EEG Learning for Robotics Complex Grasping and Dexterous Manipulation

There have been tremendous efforts to understand the biological nature of human grasping, in such a way that it can be learned and copied to prosthesis–robotics and dextrous grasping applications. Several biomimetic methods and techniques have been adopted, hence applied to analytically comprehend ways human performs grasping to duplicate human knowledge. A major topic for further study, is related to decoding the resulting EEG brainwaves during motorizing of fingers and moving parts. To accomplish this, there are a number of phases that are performed, including recording, pre-processing, filtration, and understanding of the waves. However, there are two important phases that have received substantial research attentions. The classification and decoding, of such massive and complex brain waves, as they are two important steps towards understanding patterns during grasping. In this respect, the fundamental objective of this research is to demonstrate how to employ advanced pattern recognition methods, like fuzzy c-mean clustering for understanding resulting EEG brain waves, in such a way to control a prosthesis or robotic hand, while relying sets of detected EEG brainwaves. There are a number of decoding and classification methods and techniques, however we shall look into fuzzy based clustering blended with principle component analysis (PAC) technique to help for the decoding mechanism. EEG brainwaves during a grasping and manipulation have been used for this analysis. This involves, movement of almost five fingers during a grasping defined task. The study has found that, it is not a straight forward task to decode all human fingers motions, as due to the complexity of grasping tasks. However, the adopted analysis was able to classify and identify the different narrowly performed and related fundamental events during a simple grasping task

Neuropeptide Y and neurovascular control in skeletal muscle and skin.

Neuropeptide Y (NPY) is a ubiquitous peptide with multiple effects on energy metabolism, reproduction, neurogenesis, and emotion. In addition, NPY is an important sympathetic neurotransmitter involved in neurovascular regulation. Although early studies suggested that the vasoactive effects of NPY were limited to periods of high stress, there is growing evidence for the involvement of NPY on baseline vasomotor tone and sympathetically evoked vasoconstriction in vivo in both skeletal muscle and the cutaneous circulation. In Sprague-Dawley rat skeletal muscle, Y(1)-receptor activation appears to play an important role in the regulation of basal vascular conductance, and this effect is similar in magnitude to the alpha(1)-receptor contribution. Furthermore, under baseline conditions, agonist and receptor-based mechanisms for Y(1)-receptor-dependent control of vascular conductance in skeletal muscle are greater in male than female rats. In skin, there is Y(1)-receptor-mediated vasoconstriction during whole body, but not local, cooling. As with the NPY system in muscle, this neural effect in skin differs between males and females and in addition, declines with aging. Intriguingly, skin vasodilation to local heating also requires NPY and is currently thought to be acting via a nitric oxide pathway. These studies are establishing further interest in the role of NPY as an important vasoactive agent in muscle and skin, adding to the complexity of neurovascular regulation in these tissues. In this review, we focus on the role of NPY on baseline vasomotor tone in skeletal muscle and skin and how NPY modulates vasomotor tone in response to stress, with the aim of compiling what is currently known, while highlighting some of the more pertinent questions yet to be answered

P53 and Rb tumor suppressor gene alterations in gastric cancer

Inactivation of tumor suppressor genes has been frequently observed in gastric carcinogenesis. Our purpose was to study the involvement of p53, APC, DCC, and Rb genes in gastric carcinoma. METHOD: Loss of heterozygosity of the p53, APC, DCC and Rb genes was studied in 22 gastric cancer tissues using polymerase chain reaction; single-strand conformation polymorphism of the p53 gene exons 5-6 and exons 7-8 was studied using 35S-dATP, and p53 expression was detected using a histological immunoperoxidase method with an anti-p53 clone. RESULTS AND DISCUSSION: No loss of heterozygosity was observed in any of these tumor suppressor genes; homozygous deletion was detected in the Rb gene in 23% (3/13) of the cases of intestinal-type gastric carcinoma. Eighteen (81.8%) cases showed band mobility shifts in exons 5-6 and/or 7-8 of the p53 gene. The presence of the p53 protein was positive in gastric cancer cells in 14 cases (63.6%). Normal gastric mucosa showed negative staining for p53; thus, the immunoreactivity was likely to represent mutant forms. The correlation of band mobility shift and the immunoreactivity to anti-p53 was not significant (P = .90). There was no correlation of gene alterations with the disease severity. CONCLUSIONS: The inactivation of Rb and p53 genes is involved in gastric carcinogenesis in our environment. Loss of the Rb gene observed only in the intestinal-type gastric cancer should be further evaluated in association with Helicobacter pylori infection. The p53 gene was affected in both intestinal and diffuse histological types of gastric cancer.A inativação de genes supressores tumorais tem sido freqüentemente observada na carcinogênese gástrica. O nosso objetivo foi estudar o envolvimento dos genes p53, APC, DCC e Rb no câncer gástrico. MÉTODO: Vinte e dois casos de câncer gástrico foram estudados por PCR-LOH (reação de polimerase em cadeia- perda de alelo heterozigoto) dos genes p53, APC, DCC e Rb; e por PCR-SSCP (reação de polimerase em cadeia- polimorfismo de conformação de cadeia única) dos exons 5-6 e exons 7-8 do gene p53, empregando 35S-dATP e expressão de p53 por imunoperoxidase com monoclonal anti-p53. RESULTADOS E DISCUSSÃO: Perda de alelo heterozigoto não foi detectada nos genes estudados; deleção homozigótica foi observada no gene Rb em 23% (3/13) dos casos de câncer gástrico do tipo intestinal. Desvio de motilidade de banda nos exons 5-6 e/ou exons 7-8, indicando mutação do gene p53 foi encontrada em 18 casos (81.8%). A expressão de p53 foi positiva nas células de câncer gástrico em 14 casos (63.6%). A mucosa gástrica normal não corou com anti-p53, portanto, a reatividade imune deve representar formas mutantes. A correlação de desvio de motilidade de banda e expressão imune de p53 não foi significante (p=0.90). Não houve correlação entre as alterações genéticas e a extensão da doença. CONCLUSÃO: A inativação dos genes p53 e Rb tem papel na carcinogênese gástrica no nosso meio. A perda do gene Rb observada apenas no câncer gástrico do tipo intestinal deve ser avaliada posteriormente em associação com infecção pelo Helicobacter pylori. O gene p53 estava afetado em ambos os tipos histopatológicos

カナダの少年法制 : 少年犯罪者法とその動向 (2) 完

En este trabajo indagamos la experiencia de dos actores colectivos que presentan grados diversos de organización, mostrando que su estado de forma y figura / fuerza y empuje es una expresión del estado de “precariedad corporal” que evidencian los sujetos. Es posible observar que las condiciones impuestas en la presencia corporal, por un lado, demarcan tensiones y correspondencias en la disponibilidad para la acción y la sensibilidad, por otro. Desde aquí, la producción y re– producción de estos ‘cuerpos precarios’ en torno a circuitos de encierro, tanto materiales como simbólicos, se revela como una expresión del escenario constitutivo del capital en países del Sur global como Argentina

Caracterización espectral de Quillaja saponaria (Mol.)

Revista oficial de la Asociación Española de Teledetección[EN] This paper presents a spectral reflectance characterization of the specie Quillaja saponaria (Mol.), endemic tree of Chile and valued by society due to its provision of several ecosystem services that gives to society and also for its high concentration of saponins in cortex widely used in the pharmacological industry. For spectral characterization a foliar spectral signatures protocol was designed which included standardized instrumental and environmental parameters. The spectral response of different individuals was measured to evaluate the spectral behaviour and degree of variability within species in the visible and near infrared ranges (VNIR; 400-990 nm) with two hyperspectral sensors (ASD HH and camera PDF-65-V10E). The resulting spectral signatures obtained with ASD HH showed a variation less than 5% of reflectance in VNIR and lesser than that in the transition zone from red to near infrared (red-edge; 680-730 nm). Additionally, two distinctive spectral features were detected for the specie, the first is related to a fast increase of reflectance in bands 450-480 nm and the second, to a marked decrease in the 920-970 nm range associated with water absorption features. At branch level, these distinctive features are maintained but with a smaller magnitude of reflectance, which could indicate that they are useful characteristic spectral patterns that can eventually be used for monitoring the physical health state of the specie using remote sensing. On the other hand, we used a PDF-65 camera for study the plant vigour from different health states (healthy, ill, died) with spectral vegetation index. The Plant Senescence Reflectance Index detected stress on leaves, and Triangular Vegetation Index allows for a gradually characterization of every state. This work provides the first spectral reference for one of the most important sclerophyll species of Chile.[ES] En este trabajo se presenta una caracterización de la reflectancia espectral de Quillaja saponaria (Mol.), especie endémica de Chile y principalmente valorada por los servicios ecosistémicos que brinda a la sociedad así como su elevada concentración de saponinas en la corteza, utilizada como insumo en la industria farmacéutica. Para la caracterización espectral se diseñó un protocolo de adquisición de firmas espectrales foliares, controlando pará-metros instrumentales y ambientales. Se evaluó el comportamiento espectral y el grado de variabilidad de la especie en el rango del visible e infrarrojo cercano (VNIR; 400-990 nm) con dos sensores hiperespectrales (ASD HH y cámara PDF-65-V10E). Las firmas espectrales obtenidas con el ASD HH mostraron una variación inferior al 5% de reflectancia en el VNIR y en menor medida en la zona de transición del visible al infrarrojo cercano (red-edge; 680-730 nm). Además, se detectaron dos rasgos espectrales distintivos de la especie, el primero se relaciona con un incremento rápido de la reflectancia en los 450-480 nm y el segundo, un decrecimiento entre los 920-970 nm relacionado con las bandas de absorción de agua. De hecho, al medir la reflectancia de un conjunto de ramas apiladas, éstos rasgos perduran pero con una menor magnitud, indicando un patrón espectral característico y eventualmente utilizable en campañas de monitoreo del estado físico y sanitario de la especie mediante teledetección. Usando la cámara PDF-65 se estudió el vigor de las hojas bajo diferentes condiciones sanitarias (sana, enferma, muerta) a través de los índices espectrales de vegetación. Entre los resultados, el índice PSRI (Plant Senescence Reflectance Index) detecta sectores de bajo vigor fotosintético y el TVI (Triangular Vegetation Index) permite una caracterización gradual de cada condición. Este trabajo presenta la primera referencia espectral para una de las especies de bosque esclerófilo más importante de Chile.Este trabajo fue financiado por el proyecto Fondecyt 1140319 “Vegetation Knowledge-based Indicators for Urban Sustainable Planning” de CONICYT Chile. Los autores también agradecen a AGSEN y a SPECIM por contribuir con la imagen obtenida con la cámara hiperespectral PDF-65-V10E.Acuña, T.; Mattar, C.; Hernández, HJ. (2016). Spectral characterization of Quillaja saponaria (Mol.). Revista de Teledetección. (47):65-73. https://doi.org/10.4995/raet.2016.6488SWORD65734

WISE-2005: prolongation of left ventricular pre-ejection period with 56 days head-down bed rest in women

This study tested the hypothesis that prolonged physical deconditioning affects the coupling of left ventricular depolarization to its ejection (the pre-ejection period, PEPi) and that this effect is minimized by exercise countermeasures. Following assignment to non-exercise (Control) and exercise groups (Exercise), 14 females performed 56 days of continuous head-down tilt bed rest. Measurements of the electrocardiogram (ECG) and stroke volume (Doppler ultrasound) during supine rest were obtained at baseline prior to (Pre) and after (Post) the head-down tilt bed rest (HDBR) period. Compared with Pre, the PEPi was increased following head-down tilt bed rest (main effect, P \u3c 0.005). This effect was most dominant in the Control group [Pre = 0.038 ± 0.06 s (s.d.) versus Post = 0.054 ± 0.011 s; P \u3c 0.001]. In the Exercise group, PEPi was 0.032 ± 0.005 s Pre and 0.038 ± 0.018 s Post; P= 0.08. Neither the QRS interval nor cardiac afterload was modified by head-down tilt bed rest in Control or Exercise groups. Low-dose isoprenaline infusion reversed the head-down tilt bed rest-induced delay in the PEPi. These results suggest that head-down tilt bed rest leads to a delayed onset of systolic ejection following left ventricular depolarization in a manner that is affected little by the exercise countermeasure but is related to Β-adrenergic pathways. The delayed onset of systole following head-down tilt bed rest appears to be related to mechanism(s) affecting contraction of the left ventricle rather than its depolarization. © 2010 The Authors. Journal compilation © 2010 The Physiological Society

Association of LEC and tnpA Helicobacter pylori genes with gastric cancer in a Brazilian population

<p>Abstract</p> <p>Background</p> <p><it>H. pylori </it>seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, <it>H. pylori </it>is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent <it>H. pylori </it>strains with gastric cancer.</p> <p>Methods</p> <p>DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of <it>cag</it>PAI genes (<it>cagA</it>, <it>cagA </it>promoter, <it>cagE</it>, <it>cagM</it>, <it>tnpB</it>, <it>tnpA</it>, <it>cagT </it>and the left end of the <it>cag</it>II (LEC)) and <it>babA </it>were analyzed by PCR.</p> <p>Results</p> <p>Comparison of <it>H. pylori </it>isolates from gastric cancer and gastritis patients showed significant associations of <it>tnpA </it>and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other <it>cag</it>PAI genes were detected in both groups at similar frequencies.</p> <p>Conclusions</p> <p><it>tnpA </it>and LEC of <it>H. pylori cag</it>PAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.</p

The atypical chemokine receptor ACKR2 is protective against sepsis

Sepsis is a systemic inflammatory response as a result of uncontrolled infections. Neutrophils are the first cells to reach the primary sites of infection and chemokines play a key role in recruiting neutrophils. However, in sepsis chemokines could also contribute to neutrophil infiltration to vital organs leading to multiple organ failure. ACKR2 is an atypical chemokine receptor, which can remove and degrade inflammatory CC chemokines. The role of ACK2 in sepsis is unknown. Using a model of cecal ligation and puncture (CLP), we demonstrate here that ACKR2 deficient (−/−) mice exhibited a significant reduction in the survival rate compared to similarly treated wild type (WT) mice. However, neutrophil migration to the peritoneal cavity and bacterial load were similar between WT and ACKR2−/− mice during CLP. In contrast, ACKR2−/− mice showed increased neutrophil infiltration and elevated CC chemokine levels in the lung, kidney and heart compared to the WT mice. In addition, ACKR2−/− mice also showed more severe lesions in the lung and kidney than those in the WT mice. Consistent with these results, WT mice under non-severe sepsis (90% survival) had higher expression of ACKR2 in these organs than mice under severe sepsis (no survival). Finally, the lungs from septic patients showed increased number of ACKR2+ cells compared to those of non-septic patients. Our data indicate that ACKR2 may have a protective role during sepsis, and the absence of ACKR2 leads to exacerbated chemokine accumulation, neutrophil infiltration and damage to vital organs