PROTOTIPO DE APOYO PARA EMULAR EL FUNCIONAMIENTO DEL PROTOCOLO MESI (PROTOTYPE OF SUPPORT FOR EMULATING MESI PROTOCOL OPERATION)

En los sistemas multiprocesador los datos pueden residir tanto en distintos niveles de caché como en la memoria principal. Mantener la coherencia de los datos entre los diferentes cachés y la memoria principal se conoce como el problema de coherencia de caché, el cual se puede solventar con el uso de protocolos como MESI (Modified-Exclusive-Shared-Invalid). En este trabajo se presenta el desarrollo de un prototipo cuyo objetivo es explicar el funcionamiento del protocolo antes mencionado en cursos de arquitecturas avanzadas de computadoras vistos a nivel ingeniería. El prototipo emula el funcionamiento de un sistema multiprocesador de dos procesadores (cada uno con un único nivel de caché) y la memoria principal utilizando dos tarjetas Arduino. El sistema interactúa con el usuario por medio de botones para leer y modificar datos de la memoria, así como pantallas que despliegan el contenido de las cachés y el estado en el que se encuentran.In the multiprocessor systems data can reside in different cache memory levels as in the main memory. Maintaining data coherence between different caches and main memory is known as the cache coherence problem, which can be solved with the use of protocols such as MESI (Modified-Exclusive-Shared-Invalid). This paper presents the development of a prototype whose objective is the explanation of the aforementioned protocol in courses of advanced computer architectures seen at the engineering level. The prototype emulates the operation of a multiprocessor system with two processors and the main memory using two Arduino boards. The system interacts with the user through means of buttons to read and modify data from the memory, as well as the screens that display the contents of the caches and the state in which they are located

Physico-chemical, biological and geological study of an underwater volcano in a degassing stage: Island of El Hierro

El objetivo principal del proyecto “Physico-chemical, biological and geological study of an underwater volcano in a degassing stage: Island of El Hierro”, (VULCANO-II) es estudiar, desde un punto de vista totalmente interdisciplinar, la fase de desgasificación activa del único volcán submarino monitoreado desde su nacimiento en aguas españolas. De esta forma, se pretende además, dar continuidad a los estudios multidisciplinares realizados sobre el volcán submarino de la isla de El Hierro en el contexto del proyecto del Plan Nacional VULCANO-I, (CTM2012-36317) y VULCANA (Vulcanología Canaria Submarina, IEO). Para ello, se realizará la monitorización de las propiedades físico-químicas, biológicas y geológicas del proceso eruptivo submarino de la isla de El Hierro y otros puntos sensibles, como el volcán de Enmedio entre Gran Canaria y Tenerif

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Una red para promover sistemas de salud basados en la atención primaria de salud en la Región de las Américas A network to promote health systems based on primary health care in the Region of the Americas

OBJETIVOS: Identificar los componentes relacionales de una red internacional de organizaciones de cooperación técnica y financiera que promueva el desarrollo de sistemas de salud basados en la atención primaria de salud (APS) en los países de la Región; analizar los vínculos de acción social para la cooperación en salud entre los socios colaboradores de la Organización Panamericana de la Salud (OPS); y determinar los elementos teóricos básicos que pueden contribuir a desarrollar estrategias de acción que respalden la abogacía en red. MÉTODOS: Estudio transversal cualitativo y cuantitativo basado en la identificación de informantes clave y el análisis de redes sociales. Se colectó información etnográfica y relacional de 46 organizaciones internacionales mediante un cuestionario semiestructurado autoaplicado. Participaron 29 tomadores de decisión pertenecientes a 29 organizaciones de cooperación internacional en salud (tasa de respuesta: 63,0%). La estructura y solidez de la red se evaluó mediante la densidad, la distancia, la transitividad y la centralización de los nodos. El análisis estadístico se realizó mediante los programas informáticos UCINET, PAJEK y MS Access, entre otros. RESULTADOS: Se identificó una red teórica estructuralmente centralizada, cuyos nodos aglutinados en cuatro subgrupos centrales se vincularon en una visión compartida. El liderazgo, la influencia y los intereses políticos reflejaron los vínculos cooperativos de tipo formal y técnico y el apoyo formal a favor de la propuesta, con el predominio del flujo de recursos técnicos sobre los financieros. CONCLUSIONES: Los componentes relacionales interorganizacionales y los vínculos de acción social identificados pueden influir positivamente en la conformación y consolidación de una red temática de abogacía y gestión para la cooperación técnica y financiera en apoyo a la APS en la Región de las Américas. Los vínculos de acción identificados pueden favorecer la cooperación internacional en el desarrollo de sistemas de salud basados en la APS, una vez que la OPS formule estrategias de implementación claras y tome el liderazgo para movilizar recursos financieros y generar vínculos de acción informal e interpersonal.<br>OBJECTIVES: To identify the relational components of an international network of organizations that provide technical and financial assistance to promote the development of health systems based on primary health care in the countries of the Region of the Americas; to analyze the linkages that would allow the collaborating partners of the Pan American Health Organization (PAHO) to work together on health issues; and to determine the basic theoretical elements that can help to develop action strategies that support advocacy efforts by a network. METHODS: This was a qualitative and quantitative cross-sectional study based on identifying key informants and on analyzing social networks. Ethnographic and relational information from 46 international organizations was collected through a self-administered semistructured questionnaire. From 46 international health cooperation organizations, 29 decisionmakers from 29 organizations participated (63.0% response rate). The structure and the strength of the network was evaluated in terms of density, closeness, clustering, and centralization. The statistical analysis was done using computer programs that included UCINET, Pajek, and Microsoft Access. RESULTS: We found a structurally centralized theoretical network, whose nodes were clustered into four central subgroups linked by a shared vision. The leadership, influence, and political interests reflected the formal and technical-cooperation linkages, the formal support for health systems based on primary health care, and the flow of resources being more often technical ones than financial ones. CONCLUSIONS: The interorganizational relational components and the social-action ties that were identified could help in the development and consolidation of a thematic network for advocacy and for the management of technical and financial assistance that supports primary health care in the Americas. The linkages for joint action that were identified could advance international cooperation in developing health systems based on primary health care, once PAHO formulates clear implementation strategies and takes a leadership position in mobilizing financial resources and in creating informal and interpersonal linkages for action

Una red para promover Sistemas de Salud Basados en la Atención Primaria de Salud, Revista Pan Americana de Salud (Washington, 2007)

Objetivos. Identificar los componentes relacionales de una red internacional de organizaciones de cooperación técnica y financiera que promueva el desarrollo de sistemas de salud basados en la atención primaria de salud (APS) en los países de la Región; analizar los vínculos de acción social para la cooperación en salud entre los socios colaboradores de la Organización Panamericana de la Salud (OPS); y determinar los elementos teóricos básicos que pueden contribuir a desarrollar estrategias de acción que respalden la abogacía en red. Métodos. Estudio transversal cualitativo y cuantitativo basado en la identificación de informantes clave y el análisis de redes sociales. Se colectó información etnográfica y relacional de 46 organizaciones internacionales mediante un cuestionario semiestructurado autoaplicado. Participaron 29 tomadores de decisión pertenecientes a 29 organizaciones de cooperación internacional en salud (tasa de respuesta: 63,0%). La estructura y solidez de la red se evaluó mediante la densidad, la distancia, la transitividad y la centralización de los nodos. El análisis estadístico se realizó mediante los programas informáticos UCINET, PAJEK y MS Access, entre otros. Resultados. Se identificó una red teórica estructuralmente centralizada, cuyos nodos aglutinados en cuatro subgrupos centrales se vincularon en una visión compartida. El liderazgo, la influencia y los intereses políticos reflejaron los vínculos cooperativos de tipo formal y técnico y el apoyo formal a favor de la propuesta, con el predominio del flujo de recursos técnicos sobre los financieros. Conclusiones. Los componentes relacionales interorganizacionales y los vínculos de acción social identificados pueden influir positivamente en la conformación y consolidación de una red temática de abogacía y gestión para la cooperación técnica y financiera en apoyo a la APS en la Región de las Américas. Los vínculos de acción identificados pueden favorecer la cooperación internacional en el desarrollo de sistemas de salud basados en la APS, una vez que la OPS formule estrategias de implementación claras y tome el liderazgo para movilizar recursos financieros y generar vínculos de acción informal e interpersonal

Inicio en el consumo de alcohol y tabaco y transición a otras drogas en estudiantes de Morelos, México Onset of alcohol and tobacco use and transition to other drug use among students from Morelos, Mexico

OBJETIVO: Estimar la probabilidad acumulada de ocurrencia del primer uso de alcohol y tabaco, y el riesgo de transitar hacia el uso inicial de otras sustancias (marihuana, cocaína y heroína, entre otras) en estudiantes adolescentes y adultos jóvenes de Morelos, México. MATERIAL Y MÉTODOS: Se llevó a cabo un estudio transversal en el ciclo escolar 1998-1999, en el estado de Morelos, en una muestra probabilística de estudiantes de entre 11 a 24 años de edad (n=13 293) a quienes se distribuyó un cuestionario auto-aplicable validado. Los datos se restructuraron para construir una cohorte sintética que se estudió con métodos de sobrevida y unidades discretas de tiempo. Se obtuvieron riesgos relativos y sus intervalos de confianza de 95%, con modelos multivariados de regresión de Cox. RESULTADOS: Sesenta por ciento de los varones iniciaron el uso de alcohol en promedio a los 17 y el uso de tabaco a los 18 años de edad. Las mujeres iniciaron el uso de alcohol y tabaco un año después que los hombres. El uso de otras drogas ocurrió a los 19 años de edad en promedio en 5% de las mujeres y 13% de los varones. Nueve de cada 100 estudiantes que consumieron drogas ilegales iniciaron directamente sin antes haber usado alcohol ni tabaco. En general, los estudiantes usuarios de alcohol o tabaco, o ambos, presentaron mayor riesgo de iniciar el uso de otras drogas que los no usuarios (RR=6.72; IC 95%=4.13-10.93). CONCLUSIONES: Son claras las implicaciones potenciales del presente estudio al considerar que, junto con intervenciones encaminadas a disminuir el consumo de drogas, resulta igualmente importante retardar la edad de inicio de alcohol y tabaco por sexo, ya que mediante un nuevo enfoque brinda evidencia epidemiológica que relaciona el uso de estas sustancias con el uso posterior de otras drogas en estudiantes mexicanos.<br>OBJECTIVE: To estimate the cumulative probability of occurrence of first use of alcohol and tobacco, and the risk of transition to illegal drugs (marijuana, cocaine, and heroine, among others), in adolescents and young adults, in Morelos State, Mexico. MATERIAL AND METHODS: A cross-sectional study was conducted during schoolyear 1998-1999, among 13 293 students aged 11-24 years, selected from public schools by probabilistic multistage sampling. Data were collected on sociodemographic, health status, and substance abuse variables, using a validated self-applied questionnaire. Data were restructured to assemble a synthetic cohort for discrete time survival analysis. Associations were assessed with hazard rates and 95% confidence intervals obtained by means of multivariate Cox regression models. RESULTS: Sixty percent of males started drinking alcohol at 17 years of age, and smoking tobacco at 18 years of age, on average. Women started using alcohol and tobacco one year after men. Utilization of illicit drugs occurred at 19 years of age on average in 5% of women and 13% of men. Nine out of every 100 illicit drug users started directly using illicit drugs without previous use of alcohol and/or tobacco. In general, alcohol or tobacco users were at greater risk of starting drug use than nonusers (RR=6.72; 95 % confidence interval [CI]=4.13-10.93). CONCLUSIONS: Study findings suggest that interventions to decrease drug abuse should go together with efforts to delay initiation of alcohol and tobacco use. The innovative method used in this study yields epidemiologic evidence relating early use of alcohol and tobacco with initiation of illegal drugs in Mexican students