Una solución de bajo costo de FFT para la medición de armónicos de corriente o voltaje

Una solución de bajo costo para la FFT se presenta en este documento. La principal idea radica en hacer un medidor capaz de medir armónicos de corriente o voltaje, dependiendo del trasductor que se utilice en la solución. La FFT utiliza lenguaje assembler con el fin de garantizar una recursión de código y, más aún, garantizar la utilización de poco recurso de máquina; en general, esto hace que el código y la aplicación necesiten menos tiempo para ejecutarse. Tomando una plataforma DSP, de 16 bits, junto con un transductor de voltaje o corriente se puede hacer un medidor capaz de detectar el número de armónicos deseados, con un excelente grado de precisión

Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

Necrotizing hepatopancreatitis bacterium (NHPB) is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus) with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo

Procesos no lineales en la ciencia y la sociedad

La existencia de ondas ocurre como una de las formas de manifiestación del movimiento más común en el mundo que nos rodea. Aunque las ondas lineales juegan un papel crucial en el desarrollo de la ciencia en primera aproximación, las ondas de índole no lineal se consideran como las más “realistas” para describir procesos complejos. Una gran posibilidad para el desarrollo de teoría de ondas no lineales se abrió debido a la investigación de solitones, ondas que no cambian de forma y de energía a lo largo de su desplazamiento. En este contexto, en el capítulo de Tatyana Belyaeva y Vladimir Serkin se estudia el efecto túnel cuántico usando ondas no lineales solitónicas de óptica y ondas de materia. Como es conocido, la ecuación diferencial que gobierna estos pulsos ópticos es de la familia de ecuaciones no lineales de Schrödinger, por su analogía con la famosa ecuación de la mecánica cuántica.La evolución de la sociedad en gran medida está soportada por el avance del desarrollo científico. Por ende, la aplicación de conocimientos obtenidos en esfuerzos indagatorios sobre fenómenos que ocurren en el universo es una de las premisas sobre la cual se basa todo desarrollo tecnológico y científico de la humanidad. La investigación en torno a las diferentes manifestaciones de la naturaleza conduce al análisis de entidades interactuantes que condicionan el comportamiento a posteriori de los elementos que la conforman. Es así que el estudio de sistemas interactuantes constituye un tema central en cualquier disciplina científica. Sin embargo, el análisis matemático de estos sistemas no es un problema fácil, de hecho, el estado actual del conocimiento científico y matemático dista aún mucho de comprender a detalle todos los posibles comportamientos de los sistemas complejos. El problema radica principalmente en dos factores: el primero se refiere a la gran cantidad de componentes, variables y parámetros que pueden estar interactuando, lo que obliga a analizar simplificaciones del problema; y el segundo concierne a que las interacciones generalmente no son lineales. Una de las diferencias fundamentales entre procesos lineales y no lineales es que en estos últimos no se cumple el principio de superposición. Cuando el vasto número de procesos naturales no lineales se estudia, comúnmente se modela mediante sistemas de ecuaciones no lineales. Suele ocurrir frecuentemente que la complejidad de fenómenos que ocurren en la naturaleza y sociedad en muchos aspectos es descrita y analizada incluso bajo una misma ecuación diferencial no lineal, incluyendo también en muchos casos la influencia aleatoria de otros agentes externos, por lo que la estocasticidad estará presente de una u otra manera. Esto crea un cuadro relativamente exitoso en vista de que las investigaciones de procesos que ocurren se pueden llevar a cabo en forma aislada, analizarlas abstractamente en el mundo de las matemáticas, para luego volcar todo el arsenal de conocimientos en las respectivas áreas de interés que se realizan

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Psicología: aspectos fundamentales de la formación y la profesión

El aspecto de la práctica clínica ha sido abordado primeramente por la doctora Córdoba Basulto, desde la experiencia, y de manera muy breve profundiza en el ámbito de la Psicología de la salud, rescata y enfatiza el aspecto de la atención e intervención al paciente de urología, colocándolo en la parte de sujeto y no de enfermedad. Nuevamente señalando el trabajo multidisciplinario donde cada agente contribuye con la atención. Desde una perspectiva meramente clínica y específicamente con la experiencia del psicoanálisis, Márquez, Guadarrama, López y Huitrón nos permiten observar la postura de la adolescencia en el proceso terapéutico, indicando que la mejor forma de tratar a un adolescente no es lo individual, ni lo familiar, sino lo grupal.Este libro es una compilación de aportaciones que permiten observar el estado actual de la psicología en México, permitiendo vislumbrar los retos reales que no solamente tienen los alumnos que asumir en su formación profesional, sino todos aquellos que se encuentran laborando en esta basta disciplina. En este sentido, el mundo globalizado y el empleo exagerado de la tecnología se convierten en nuevas exigencias que propician a su vez nuevas formas, no sólo de atención, sino de estudio e investigación que le permitan la comprensión del comportamiento humano. La Psicología mexicana en los últimos años ha dejado de ser dogmática para convertirse en una ciencia amplia y de visión, lo que le ha permitido incursionar en nuevos campos de conocimiento como el de la psicología de la salud o de la psicología criminal. Es decir ha dejado de ser una psicología de diagnóstico y clínica para convertirse en una ciencia que asume al individuo como un ser social, complejo o bien como algunos ya lo han señalado como un ente psicosociobiológico

Local hydrological conditions influence tree diversity and composition across the Amazon basin

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation