El aire: hábitat y medio de transmisión de microorganismos

La atmósfera no tiene una microbiota autóctona pero es un medio para la dispersión de muchos tipos de microorganismos (esporas, bacterias, virus y hongos), procedentes de otros ambientes. Algunos han creado adaptaciones especializadas que favorecen su supervivencia y permanencia. Los microorganismos dispersados por el aire tiene una gran importancia biológica y económica. Producen enfermedades en plantas, animales y humanos, causan alteración de alimentos y materiales orgánicos y contribuyen al deterioro y corrosión de monumentos y metales. La Microbiología del aire comienza en el siglo XIX, con Pasteur y Miquel que diseñaron métodos para estudiar los microorganismos en el aire y descubrir la causa de algunas enfermedades. Desde entonces numerosos investigadores han trabajado en este campo tanto en el aire exterior como en recintos cerrados. Las enfermedades transmitidas por el aire, producidas por bacterias, virus y hongos, son las respiratorias (neumonía, tosferina, tuberculosis, legionelosis, resfriado, gripe), sistémicas (meningitis, sarampión, varicela, micosis) y alérgicas

Resistance Analysis for a Trimaran

Importance has been given to resistance analysis for various types of vessels; however explicit guidelines applied to multihull vessels have not been clearly defined. The purpose of this investigation is to highlight the importance of the vessel's layout in terms of three axes positioning, the transverse (separation), the longitudinal (stagger) and the vertical (draught) with respect to resistance analysis. A vessel has the potential to experience less resistance, at a particular range of speeds, for a vast selection of hull positioning. Many potential layouts create opportunities of various design for both the commercial and leisure market

Design of an adaptive LNA for hand-held devices in a 1-V 90-nm standard RF CMOS technology: From circuit analysis to layout

[EN]: This paper deals the design of a reconfigurable Low-Noise Amplifier (LNA) for the next generation of wireless hand-held devices by using a lumped circuit approach based on physical laws. The purpose is not only to present simulation results showing the fulfillment of different standard specifications, but also to demonstrate that each design step has a physical meaning such that the mathematical design flow is simple as well as suitable for hand-work in both laboratory and classroom. The circuit under analysis, which is designed according to technological design rules of a 90nm CMOS technology, is a two-stage topology including inductive-source degeneration, MOS-varactor based tuning networks, and programmable bias currents. This proposal, with reduced number of inductors and minimum power dissipation, adapts its performance to different standard specifications; the LNA is designed to cope with the requirements of GSM (PCS1900), WCDMA, Bluetooth and WLAN (IEEE 802.11b-g). In order to evaluate the effect of technology parasitics on the LNA performance, simulation results demonstrate that the LNA features NF16dB, S11-3.3 dBm over the 1.85-2.48 GHz band. For all the standards under study the adaptive power consumption varies from 25.3 mW to 53.3mW at a power supply of 1-V. The layout of the reconfigurable LNA occupies an area of 1.8mm2.[ES]: Este trabajo presenta el diseño de un amplificador de bajo ruido, LNA (del inglés Low‐Noise Amplifier) reconfigurable para la siguiente generación de dispositivos portátiles de comunicación inalámbricos, usando la aproximación de circuitos concentrados sustentada en leyes físicas. El propósito de este trabajo no es sólo presentar resultados de simulación que muestran el cumplimiento de especificaciones para cada estándar, sino también demostrar que cada paso de diseño tiene un significado físico haciendo que el procedimiento matemático de diseño sea simple y adecuado para el trabajo a mano tanto para actividades en laboratorio como en el aula. El circuito bajo análisis, diseñado en una tecnología CMOS 90nm, consta de dos etapas que incluyen degeneración inductiva de fuente, redes de entonado basadas en varactores MOS, y corrientes de polarización programables. Esta propuesta, con reducido número de inductores y mínima disipación de potencia, adapta su desempeño a las diversas especificaciones de cada estándar; el LNA se diseña para cubrir los requerimientos de GSM (PCS1900), WCDMA, Bluetooth y WLAN (IEEE 802.11b‐g). Para evaluar el efecto de las no idealidades de la tecnología en el desempeño del LNA, las simulaciones demuestran que el circuito cumple parámetros como NF16dB, S11< ‐5.5dB, S22‐3.3dBm en la banda 1.85‐ 2.48GHz. Para todos los estándares bajo estudio, el consumo adaptivo de potencia varía de 25.3 mW a 53.3mW usando una fuente de alimentación de 1‐V. El patrón geométrico del LNA reconfigurable consume un área de 1.8mm2.Peer Reviewe

Thiol precursors in Catarratto Bianco Comune and Grillo grapes and effect of clari&#64257;cation conditions on the release of varietal thiols in wine

Background and aims: Varietal thiols characterize the typical aroma of several white wines, as Sauvignon blanc. Their presence was suggested in two Sicilian grape cultivars, Catarratto Bianco Comune (CBC) and Grillo, thought it was not analytically proved to date. Methods and Results: Varietal thiol precursors and free varietal thiols were assessed in CBC and Grillo grapes, musts and wines by UPLC/high resolution mass spectrometry (HRMS). The isobaric compounds S-3-(hexanal)-glutathione (GSH-3MHAl) and S-3-(4-mercapto-4-methylpentan-2-one)-glutathione (GSH-4MMP) were discriminated by comparing their accurate masses and HR-MS/MS spectra with those of their synthetic standards. GSH-3MHAl, S-3-(hexan-1-ol)-glutathione (GSH-3MH) and S-3-(hexan-1-ol)-cysteine occurred in grape, must and wine, while GSH-4MMP and its hydrolysed forms did not. Their amounts decreased during the industrial winemaking processes, mostly following the grape pressing. We compared clarification conditions exposing must to either air or CO2 in terms of thiol precursors\u2019 and free thiols\u2019 content in wine. However, negligible differences were observed. Concentrations of free thiols in the range 400\u20131100 ng/L were found in the wines and they were not affected to the two clarification conditions adopted. Conclusion: The isobaric GSH-3MHAl and GSH-4MMP were clearly distinguished for the first time by UPLC-HRMS through their retention times and MS spectra. The varietal thiols were firstly revealed CBC and Grillo wines. The air-free and air- exposed clarification poorly affected the levels of varietal thiols. Significance of the study: This research highlights the major impact of the varietal thiols (mainly 3\u2013mercapto-hexan-1-ol and its acetate form) on the sensory properties of CBC and Grillo wines

Implementation of binary stochastic STDP learning using chalcogenide-based memristive devices

The emergence of nano-scale memristive devices encouraged many different research areas to exploit their use in multiple applications. One of the proposed applications was to implement synaptic connections in bio-inspired neuromorphic systems. Large-scale neuromorphic hardware platforms are being developed with increasing number of neurons and synapses, having a critical bottleneck in the online learning capabilities. Spike-timing-dependent plasticity (STDP) is a widely used learning mechanism inspired by biology which updates the synaptic weight as a function of the temporal correlation between pre- and post-synaptic spikes. In this work, we demonstrate experimentally that binary stochastic STDP learning can be obtained from a memristor when the appropriate pulses are applied at both sides of the device

Neuroglial involvement in abnormal glutamate transport in the cochlear nuclei of the Igf1—/— mouse

Insulin-like growth factor 1 (IGF-1) is a powerful regulator of synaptic activity and a deficit in this protein has a profound impact on neurotransmission, mostly on excitatory synapses in both the developing and mature auditory system. Adult Igf1—/— mice are animal models for the study of human syndromic deafness; they show altered cochlear projection patterns into abnormally developed auditory neurons along with impaired glutamate uptake in the cochlear nuclei, phenomena that probably reflect disruptions in neuronal circuits. To determine the cellular mechanisms that might be involved in regulating excitatory synaptic plasticity in 4-month-old Igf1—/— mice, modifications to neuroglia, astroglial glutamate transporters (GLTs) and metabotropic glutamate receptors (mGluRs) were assessed in the cochlear nuclei. The Igf1—/— mice show significant decreases in IBA1 (an ionized calcium-binding adapter) and glial fibrillary acidic protein (GFAP) mRNA expression and protein accumulation, as well as dampened mGluR expression in conjunction with enhanced glutamate transporter 1 (GLT1) expression. By contrast, no differences were observed in the expression of glutamate aspartate transporter (GLAST) between these Igf1—/— mice and their heterozygous or wildtype littermates. These observations suggest that congenital IGF-1 deficiency may lead to alterations in microglia and astrocytes, an upregulation of GLT1, and the downregulation of groups I, II and III mGluRs. Understanding the molecular, biochemical and morphological mechanisms underlying neuronal plasticity in a mouse model of hearing deficits will give us insight into new therapeutic strategies that could help to maintain or even improve residual hearing when human deafness is related to IGF-1 deficiencyThis work was supported by the Spanish Ministerio de Economía y Competitividad (MINECO; SAF2016-788898-C2-1R) to JJ and VF-S; Seventh Framework Programme (FP7)-HEALTH- 2012-INNOVATON (#304925) to JJ; CIBERER/FEDER ACCI-ER16P5AC7091 and ER17P5AC7612 to LR-R; and Spanish MINECO/FEDER (SAF2014-53979-R), FP7- PEOPLE-2013-IAPP TARGEAR, CIBERER/FEDER (ACCIER16P5AC7091 and ER17P5AC7612) to IV-N. LR-R holds a contract supported by CIBERER (Institute of Health Carlos III) co-financed with FEDER fund

Total organic carbon, total nitrogen and chemical characteristics of an haplic cambisol after biochar incorporation

Biochar has been used as a soil conditioner to increase the soil organic carbon content and to improve the soil chemical characteristics. However, the effect of biochar on soil is still not clear and the soil type and biochar composition should also play an important role. In this context, the main objective of this work was to evaluate the effect of biochar application on the organic carbon (C) content and on chemical characteristics of subtropical Cambisol. The field experiment was located at the State University of Centro ‐ Oeste in Irati, Brazil, and the soil was classified as an Haplic Cambisol (Embrapa, 1999). The applied biochar was composed mainly by fine residues ( 70% < 2mm ) of an eucalyptus biochar that was a waste of the local steel industry. In February 2010, four increasing doses of biochar were applied to the soil (T1 ‐ 0 t ha ‐ 1 ; T2 ‐ 10 t ha ‐ 1 ; T3 ‐ 20 t ha ‐ 1 and T4 ‐ 40 t ha ‐ 1 ) with four replicates. Soil samples were composed by three subsamples collected within each plot. Biochar was applied on the soil surface and thereafter it was incorporated into a 0 ‐ 10 cm soil depth with an harrow. Soil samples were collected in September 2011 at four soil depths: 0 ‐ 5; 5 ‐ 10; 10 ‐ 20 and 20 ‐ 30 cm. The samples were air dried and passed through a 2 mm sieve. Soil C and nitrogen (N) contents were determined by dry combustion and the soil characteristics assessed were: pH in water, available P, exchangeable K, Ca, Mg and Al, potential acidity (H + Al), cation exchange capacity (CEC), effective cation exchange capacity (ECEC) and base saturation (V%) (Tedesco et al., 1995). The mean values were compared using SAS software (Tukey 10%). The main alterations in soil characteristics were observed in the superficial depth (0 ‐ 5 cm) (Table 1) probably due to the permanence of the biochar fine particles at the soil surface. In this layer, the application of 40 t ha ‐ 1 of biochar (treatment T4) increased in 15.5 g kg ‐ 1 the C content in comparison to treatment T1. The treatments T2 and T3 also increased the C content, but the differences were not significant. N content was not affected by biochar application. The highest dose of biochar (treatment T4) promoted an increase of the C/N ratio from 12 to 16 at the 0 ‐ 5 cm depth. Treatment T4 also increased the soil pH value in comparison to treatment T1. In addition, the contents of available P, exchangeable K and Ca where higher under treatment T4 in comparison to treatment T1 (Table 1). In opposition, exchangeable Mg content, Al+H, V% and CEC were not altered by any treatment, but T4 increased the ECEC in 3.1 cmol c dm ‐ 3 in comparison to T1. The results observed are probably due the high C and ash (26,5%) contents of biochar. A contribution of the functional groups on the surface of the biochar to the ECEC should not be excluded (Sparkes & Stoutjesdijk, 2011). Our results indicate that after two years of biochar application an increase of soil organic carbon and a positive impact on the soil chemical characteristics at the soil surface were attained, but only with the highest tested dose (40 t ha ‐ 1 ) .Peer reviewe

Understanding the local and remote source contributions to ambient O3 during a pollution episode using a combination of experimental approaches in the Guadalquivir valley, southern Spain

The Guadalquivir Valley is one of three major O3 hotspots in Spain. An airborne and surface measurement campaign was carried out from July 9th to 11th, 2019 to quantify the local/regional O3 contributions using experimental approaches. Air quality and meteorology data from surface measurements, a microlight aircraft, a helium balloon, and remote sensing data (TROPOMI-NO2-ESA) were used to obtain the 3D distribution of O3 and various tracer pollutants. O3 accumulation over 2.5 days started with inputs from oceanic air masses transported inland by sea breezes, which drew O3 and its precursors from a local/regional origin to the northeastern end of the basin. The orographic–meteorological setting of the valley caused vertical recirculation of the air masses inside the valley that caused the accumulation by increasing regional background O3 concentration by 25–30 ppb. Furthermore, possible Mediterranean O3 contributions and additional vertical recirculation through the entrainment zone of the convective boundary layer also contributed. Using particulate matter finer than 2.5 μm (PM2.5), ultrafine particles (UFP), and black carbon (BC) as tracers of local sources, we calculated that local contributions increased regional O3 levels by 20 ppb inside specific pollution plumes transported by the breeze into the valley, and by 10 ppb during midday when flying over an area with abundant agricultural burning during the morning. Air masses that crossed the southern boundaries of the Betic system at mid-altitude (400–1850 m a.s.l.) on July 10th and 11th may have provided additional O3. Meanwhile, a decreasing trend at high altitudes (3000–5000 m a.s.l.) was observed, signifying that the impact of stratospheric O3 intrusion decreased during the campaign