Effect of influenza-induced fever on human bioimpedance values

BACKGROUND AND AIMS: Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. METHODS: Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. RESULTS: For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). CONCLUSIONS: There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states

Determination of thermal conductivity variation through Modified Transient Plane Source (MTPS), and its relationship with porosity variation on thermally treated Prada limestone

In this research, the variation of thermal conductivity with temperature of a limestone and its relationship with porosity is studied. Samples from Prada formation, a lower Cretaceous limestone from the Catalan Pyrenees (Spain), obtained from the Tres Ponts road tunnel were subjected to temperatures of 105, 300, and 600 °C and then cooled at a slow rate by air-cooling to laboratory temperature. Open porosity tests were determined before and after heating to evaluate the porosity increase and the micro-cracks growth. Complementarity, thermal conductivity was measured in the rock samples before and after the application of a thermal treatment by means of C-Therm TCi device, a Modified Transient Plane Source (MTPS). This is a non-invasive, quick, and precise method, when compared with other steady-state laboratory alternatives, widely used to directly determine thermal properties of rock samples. A clear decrease in the thermal conductivity of above 10% was observed for samples heated at 600 °C, probably due to a dramatic increase in porosity. The obtained results could be of great interest for the incorporation of the effect of temperature on rock in numerical models, to evaluate the potential impacts induced by eventual fires developed inside the Tres Ponts tunnel.This work was supported by the Department of Geological and Geotechnical Engineering, Universitat Politècnica de València

Temperature-Induced Explosive Behaviour and Thermo-Chemical Damage on Pyrite-Bearing Limestones: Causes and Mechanisms

In this investigation, two different varieties of ‘Prada’ limestones were studied: a dark grey texture, bearing quartz, clay minerals, organic matter and pyrites, and a light grey texture with little or no presence of such components. We have observed two effects of different intensity when heating the dark texture from 400 °C: (1) the explosion of certain samples and (2) greater thermal damage than in the light grey texture. Chemical and mineralogical composition, texture, microstructure, and physical properties (i.e. colour, open porosity, P and S-wave velocity) have been evaluated at temperatures of 105, 300, 400, and 500 °C in order to identify differences between textures. The violence of the explosive events was clear and cannot be confounded with ordinary splitting and cracking on thermally treated rocks: exploded samples underwent a total loss of integrity, displacing and overturning the surrounding samples, and embedding fragments in the walls of the furnace, whose impacts were clearly heard in the laboratory. Thermogravimetric results allowed the identification of a process of oxidation of pyrites releasing SO2 from 400 °C. This process jointly with the presence of microfissures in the dark texture, would cause a dramatic increase in pore pressure, leading to a rapid growth and coalescence of microcracks that leads to a process of catastrophic decay in rock integrity. In addition to the explosive events, average ultrasound velocities and open porosity showed a greater variation in the dark grey texture from 400 °C. That result also points towards a significant contribution of oxidation of pyrites on the thermo-chemical damage of the rock, among other factors such as the pre-existence of microfissures and the thermal expansion coefficient mismatch between minerals. Implications in underground infrastructure and mining engineering works are critical, as the explosive potential of pyrite-bearing limestones bears risk for mass fracturing and dramatic strength decay from 400 °C. Moreover, SO2 released has harmful effects on health of people and the potential to form acid compounds that corrode materials, shortening their durability and increasing maintenance costs.This work was supported by the Spanish Government [Grant number RTI2018-099052-B-I00] and by the Department of Geological and Geotechnical Engineering, Universitat Politècnica de València

Spin magnetotransport in a two-dimensional electron system confined in a quantum well

We show a simple model that computes the magnetoconduction in a two-dimensional electron system (2DES) where the spin is another degree of freedom in the system. The 2DES is confined in a quantum well (QW) immersed in a heterostructure, where the Rashba spin–orbit interaction is present. When an external magnetic field is applied to the system, the competition between the spin–orbit interaction and the Zeeman effect on the magnetoconduction of the 2DES is analysed, in the cases where one or two sub-bands are occupied in the QW. In the model different spin-oriented 2DES can be treated independently, with a spin current associated with each system. The model has been tested with experimental results obtained from a 2DES formed in an InGaAs layer

Predicting the Uniaxial Compressive Strength of a Limestone Exposed to High Temperatures by Point Load and Leeb Rebound Hardness Testing

The effect of exposure to high temperature on rock strength is a topic of interest in many engineering fields. In general, rock strength is known to decrease as temperature increases. The most common test used to evaluate the rock strength is the uniaxial compressive strength test (UCS). It can only be carried out in laboratory and presents some limitations in terms of the number, type and preparation of the samples. Such constrains are more evident in case of rocks from historical monuments affected by a fire, where the availability of samples is limited. There are alternatives for an indirect determination of UCS, such as the point load test (PLT), or non-destructive tests such as the Schmidt’s hammer, that can also be performed in situ. The aims of this research are: (i) measuring the effect of high temperatures and cooling methods on the strength and hardness of a limestone named Pedra de Borriol widely used in several historic buildings on the E of Spain, and (ii) studying the possibility of indirectly obtaining UCS by means of PLT and Leeb hardness tests (LHT), using Equotip type D. Limestone samples were heated to 105 (standard conditions), 200, 300, 400, 500, 600, 700, 800 and 900 ºC and cooled slowly (in air) and quickly (immersed in water). After that, UCS, PLT and LHT tests were performed to evaluate the changes as temperature increases. Results show decreases over 90% in UCS, of between 50 and 70% in PLT index and smaller than 60% in LHT index. Insignificant differences between cooling methods were observed, although slowly cooled samples provide slightly higher values than quickly cooled ones. The results indicate that LHT can be used to indirectly estimate UCS, providing an acceptable prediction. Research on correlating strength parameters in rocks after thermally treated is still scarce. This research novelty provides correlations to predict UCS in historic buildings if affected by a fire, from PLT and non-destructive methods such as LHT whose determination is quicker and easier.The authors acknowledge the support by Canteras Bernad SL which has generously provided samples, and Department of Geotechnical and Geological Engineering of Universitat Politècnica de València and Department of Civil Engineering of Universidad de Alicante, for its continuous support. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature

Hybrid strategy for unstable patients with severe carotid and cardiac disease requiring surgery

Background: Concurrent severe carotid and cardiac disease is a challenging situation where staged surgery is probably the most common strategy. However, in patients with an unstable clinical presentation, the best approach is still a matter of debate. The aim of the study was to report in-hospital and midterm outcome in patients who received carotid artery stenting and synchronous cardiac surgery. Methods: From June 1998 to July 2012, 54 consecutive patients who were treated at a high-volume university medical center with this hybrid approach were included in the study. All of the patients received carotid angioplasty while being administered aspirin and regular unfractionated heparin. Then, all of the patients were immediately transferred to the operating room for coronary and/or cardiac valve surgery. All of the patients were administered aspirin and clopidogrel once bleeding was ruled out, after surgery. Results: There were 5 in-hospital surgical related deaths, and no patient suffered a stroke or required carotid urgent re-intervention. At follow-up (55 ± 28 months; range 1–144 months), there were no new neurological deficits, while one additional death occurred. Conclusions: In this series, synchronous carotid stenting and cardiac surgery were feasible with an acceptable complication rate in a high-surgical-risk population, which could not undergo staged procedures.

Estudio y desarrollo de interfaces avanzadas orientadas a sistemas de robótica

El término Robot se aplica a una variedad de sistemas que van desde los más simples manipuladores industriales, a los robots móviles "inteligentes", equipados con múltiples sensores y actuadores, capaces de adaptarse a diferentes entornos y moverse en forma autónoma en ellos. Los desarrollos en este campo abarcan una amplia gama de especialidades, desde la mecánica a la electrónica e informática. Dentro de la especialidad electrónica y en común con la Instrumentación Virtual, involucra el conocimiento y aplicación de sensores, actuadores, software de procesamiento e interfaces gráficas para la supervisión y comando remoto. Este Proyecto tiene como objetivo estudiar y desarrollar nuevas tecnologías en percepción en tiempo real, seguimiento y comando desde dispositivos móviles, interfaces basadas en BCI, navegación y control de tracción inteligente. Como resultado, se esperan obtener interfaces y algoritmos de procesamiento para plataformas portátiles basadas en Android y módulos Arduino.Eje: Procesamiento de Señales y Sistemas de Tiempo RealRed de Universidades con Carreras en Informática (RedUNCI

Land-use change and windstorms legacies drove the recolonization dynamics of laurel forests in Tenerife, Canary islands

Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities. In the past, Canary laurel forests have been greatly altered by logging, livestock and agriculture. The remains of laurel forests are currently protected in the Canary Islands (Spain). However, we miss basic information needed for their restoration and adaptive management, such as tree longevity, growth potential and responsiveness to natural and anthropogenic disturbances. Using dendrochronological methods, we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island. Wood cores were collected from over 80 trees per stand at three stands per forest. We used ring-width series to estimate tree ages and calculate annual basal area increments (BAI), cumulative diameter increases, and changes indicative of released and suppressed growth. Twelve tree species were found in all stands, with Laurus novocanariensis, Ilex canariensis and Morella faya being the most common species. Although some individuals were over 100 years old, 61.8%–88.9% of the trees per stand established between 1940 and 1970, coinciding with a post-war period of land abandonment, rural exodus and the onset of a tourism economy. Some trees have shown growth rates larger than 1 ​cm diameter per year and most species have had increasing BAI trends over the past decades. Strong growth releases occurred after windstorms at both sites, but the effects of windstorms were site-dependent, with the 1958 storm affecting mainly the eastern tip of the island (Anaga massif) and the 1991 storm the western tip (Teno massif). Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms, passive restoration may be sufficient to regenerate this habitat in currently degraded areas.12 página

Estudio de Mercado para la Creación de una Granja Agroturística en los Ejidos Palo Blanco, La Puntilla y Tarabitas, Municipio de Tamiahua, Veracruz

El objetivo de este proyecto es determinar las características sociales y económicas, para implementar una granja Agroturistica para el desarrollo de los habitantes en el Ejido Palo Blanco, La Puntilla y Tarabitas, municipio de Tamiahua. Con los resultados obtenidos a través de las encuestas aplicadas, las necesidades de estas localidades y la falta de información sobre el agroturismo, encontrando que si se cuenta con los servicios necesarios que una Granja Agroturistica ofrecería y diversos paquetes que se ofertarían, así también precios de la competencia, se analizó la competitividad de esta y se crearon estrategias de promoción. Todo esto dio como resultado, que efectivamente, el sector del turismo necesita contar con otras opciones para sus usuarios puedan elegir la que mejor satisface sus necesidades, lo que permitiría aumentar el turismo en el municipio de Tamiahua y también una mejora económica para los habitantes de las localidades

Tree-ring distinctness, dating potential and climatic sensitivity of laurel forest tree species in Tenerife Island

Producción CientíficaMacaronesian laurel forests are the only remnants of a subtropical palaeoecosystem dominant during the Tertiary in Europe and northern Africa. These biodiverse ecosystems are restricted to cloudy and temperate insular environments in the North Atlantic Ocean. Due to their reduced distribution area, these forests are particularly vulnerable to anthropogenic disturbances and changes in climatic conditions. The assessment of laurel forest trees’ response to climate variation by dendrochronological methods is limited because it was assumed that the lack of marked seasonality would prevent the formation of distinct annual tree rings. The aims of this study were to identify the presence of annual growth rings and to assess the dendrochronological potential of the most representative tree species from laurel forests in Tenerife, Canary Islands. We sampled increment cores from 498 trees of 12 species in two well-preserved forests in Tenerife Island. We evaluated tree-ring boundary distinctness, dating potential, and sensitivity of tree-ring growth to climate and, particularly, to drought occurrence. Eight species showed clear tree-ring boundaries, but synchronic annual tree rings and robust tree-ring chronologies were only obtained for Laurus novocanariensis, Ilex perado subsp. platyphylla, Persea indica and Picconia excelsa, a third of the studied species. Tree-ring width depended on water balance and drought occurrence, showing sharp reductions in growth in the face of decreased water availability, a response that was consistent among species and sites. Inter-annual tree-ring width variation was directly dependent on rainfall input in the humid period, from previous October to current April. The four negative pointer years 1995, 1999, 2008 and 2012 corresponded to severe drought events in the study area. This study gives the first assessment of dendrochronological potential and tree-ring climate sensitivity of tree species from the Tenerife laurel forest, which opens new research avenues for dendroecological studies in Macaronesian laurel forests.Ministerio de Ciencia, Innovación y Universidades (projects PID2019-109906RA-I00, PID2020-118444GA-100 and PID2019-106908RA-I00/AEI/10.13039/501100011033)Ministerio de Ciencia, Innovación y Universidades (predoctoral contract PRE2018-084106)Ministerio de Economía, Industria y Competitividad (project CGL2017-87309-P and postdoctoral grant IJC2019-040571-I)Junta de Castilla y León (projects VA113G19 and IR2020-1-UVA08)Universidad de Valladolid (predoctoral contract 113-2019PREUVA22)Comunidad de Madrid (project S2018/EMT-4338