Advancing high-throughput combinatorial aging studies of hybrid perovskite thin films via precise automated characterization methods and machine learning assisted analysis.

To optimize material stability, automated high-throughput workflows are of increasing interest. However, many of those workflows either employ synthesis techniques not suitable for large-area depositions or are carried out in ambient conditions, which limits the transferability of the results. While combinatorial approaches based on vapour-based depositions are inherently scalable, their potential for controlled stability assessments has yet to be exploited. Based on MAPbI3 thin films as a prototypical system, we demonstrate a combinatorial inert-gas workflow to study intrinsic materials degradation, closely resembling conditions in encapsulated devices. Specifically, we probe the stability of MAPbI3 thin films with varying residual PbI2 content. A comprehensive set of automated characterization techniques is used to investigate the structure and phase constitution of pristine and aged thin films. A custom-designed in situ UV-Vis aging setup is used for real-time photospectroscopy measurements of the material libraries under relevant aging conditions, such as heat or light-bias exposure. These measurements are used to gain insights into the degradation kinetics, which can be linked to intrinsic degradation processes such as autocatalytic decomposition. Despite scattering effects, which complicate the conventional interpretation of in situ UV-Vis results, we demonstrate how a machine learning model trained on the comprehensive characterization data before and after the aging process can link changes in the optical spectra to phase changes during aging. Consequently, this approach does not only enable semi-quantitative comparisons of material stability but also provides detailed insights into the underlying degradation processes which are otherwise mostly reported for investigations on single samples.

An In Situ Evaluation of Different CAM Plants as Plant Microbial Fuel Cells for Energy Recovery in the Atacama Desert.

Excess energy derived from photosynthesis can be used in plant microbial fuel cell (PMFC) systems as a sustainable alternative for the generation of electricity. In this study, the in situ performance of CAM (Crassulacean acid metabolism) plants in Calama, in the Atacama Desert, was evaluated for energy recovery using PMFCs with stainless steel AISI 316L and Cu as electrodes. The plant species evaluated included Aloe perfoliata, Cereus jamacaru, Austrocylindropuntia subulata, Agave potatorum, Aloe arborescens, Malephora crocea, and Kalanchoe daigremontiana. Among the plant species, Kalanchoe daigremontiana demonstrated significant potential as an in situ PMFC, showing a maximum cell potential of 0.248 V and a minimum of 0.139 V. In addition, the cumulative energy for recovery was about 9.4 mWh m-2 of the electrode. The use of CAM plants in PMFCs presents a novel approach for green energy generation, as these plants possess an inherent ability to adapt to arid environments and water-scarce areas such as the Atacama Desert climate.

Corrosion of Reinforced A630-420H Steel in Direct Contact with NaCl Solution.

The deterioration of reinforced concrete structures in marine environments presents multiple problems due to the premature degradation of reinforced steel. This work aimed to study the corrosion of reinforced A630-420H steel when exposed to a 0.5 M NaCl solution. Although this carbon steel is the most widely used material for reinforced concrete structures in Chile, there is limited research on its resistance to corrosion when in contact with saline solutions. The electrochemical reactions and their roles in the corrosion rate were studied using linear sweep voltammetry, weight loss, scanning electron microscopy, and X-ray diffraction techniques. This analysis is unique as it used the superposition model based on mixed potential theory to determine the electrochemical and corrosion parameters. The outcomes of this study show that A630-420H steel has a higher corrosion rate than those of the other commercial carbon steels studied. This fact can be attributed to the competition between the cathodic oxygen reduction reaction and hydrogen evolution reaction, which also depends on the environmental conditions, exposure time, stabilization of the corrosion products layer, and presence of chloride ions. Additionally, the results under mechanical stress conditions show a brittle fracture of the corrosion product oriented longitudinally in the direction of the bend section, where the presence of pores and cracks were also observed. The corrosion products after corrosion were mainly composed of magnetite and lepidocrocite oxide phases, which is in concordance with the electrochemical results.

Metal Recovery from Natural Saline Brines with an Electrochemical Ion Pumping Method Using Hexacyanoferrate Materials as Electrodes.

The electrochemical ion pumping device is a promising alternative for the development of the industry of recovering metals from natural sources-such as seawater, geothermal water, well brine, or reverse osmosis brine-using electrochemical systems, which is considered a non-evaporative process. This technology is potentially used for metals like Li, Cu, Ca, Mg, Na, K, Sr, and others that are mostly obtained from natural brine sources through a combination of pumping, solar evaporation, and solvent extraction steps. As the future demand for metals for the electronic industry increases, new forms of marine mining processing alternatives are being implemented. Unfortunately, both land and marine mining, such as off-shore and deep sea types, have great potential for severe environmental disruption. In this context, a green alternative is the mixing entropy battery, which is a promising technique whereby the ions are captured from a saline natural source and released into a recovery solution with low ionic force using intercalation materials such as Prussian Blue Analogue (PBA) to store cations inside its crystal structure. This new technique, called "electrochemical ion pumping", has been proposed for water desalination, lithium concentration, and blue energy recovery using the difference in salt concentration. The raw material for this technology is a saline solution containing ions of interest, such as seawater, natural brines, or industrial waste. In particular, six main ions of interest-Na+, K+, Mg2+, Ca2+, Cl-, and SO42--are found in seawater, and they constitute 99.5% of the world's total dissolved salts. This manuscript provides relevant information about this new non-evaporative process for recovering metals from aqueous salty solutions using hexacianometals such as CuHCF, NiHCF, and CoHCF as electrodes, among others, for selective ion removal.

Ultrafine Kaolinite Removal in Recycled Water from the Overflow of Thickener Using Electroflotation: A Novel Application of Saline Water Splitting in Mineral Processing.

The presence of ultrafine clay particles that are difficult to remove by conventional filtration creates many operational problems in mining processing systems. In this work, the removal of clay suspensions has been investigated using an electroflotation (EF) process with titanium electrodes. The results show that EF is a viable and novel alternative for removing ultrafine particles of kaolinite-type clay present in sedimentation tank overflows with low salt concentrations (<0.1 mol/L) in copper mining facilities based on the saline water splitting concept. Maximum suspended solid removal values of 91.4 and 83.2% in NaCl and KCl solutions, respectively, were obtained under the experimental conditions of the constant applied potential of 20 V/SHE, salinity concentration of 0.1 mol/L, and electroflotation time of 10 and 20 min in NaCl and KCl solutions, respectively. Furthermore, the visual evidence of particle aggregation by flocculation during the experiments indicates a synergy between EF and electrocoagulation (EC) that enhances the removal of ultrafine particles of kaolinite.

Corrosion of Titanium Electrode Used for Solar Saline Electroflotation.

The solar electroflotation (EF) processes using saline electrolytes are today one of the great challenges for the development of electrochemical devices, due to the corrosion problems that are generated during the operation by being in permanent contact with Cl- ions. This manuscript discloses the corrosion behavior of titanium electrodes using a superposition model based on mixed potential theory and the evaluation of the superficial performance of the Ti electrodes operated to 4 V/SHE solar electroflotation in contact with a solution of 0.5 M NaCl. Additionally provided is an electrochemical analysis of Ti electrodes regarding HER, ORR, OER, and CER that occur during the solar saline EF process. The non-linear superposition model by mixed potential theory gives electrochemical and corrosion parameters that complement the information published in scientific journals, the corrosion current density and corrosion potential in these conditions is 0.069 A/m2 and -7.27 mV, respectively. The formation of TiO2 and TiOCl on the anode electrode was visualized, resulting in a reduction of its weight loss of the anode electrode.

Rare earth elements as statistical sentinels of pollution and paleoenvironments?: Application to a highly polluted estuary in southwestern Spain.

Multivariate analyses have been applied to the REE contents of three cores collected in the Tinto estuary, SW Spain, an extremely polluted area. Results indicate an extremely correlation between all REE, which behave as a single variable. A slight natural pollution peak and three anthropogenic pollution peaks are identified, related with the first mining activities, the Roman period and a recent intensive mining accompanied by a heavy industrial pollution. In all these peaks, the increase of Cu is parallel to that of MREE, which are configured as the best indicators of pollution among REE. Statistical analyses clearly differentiate four groups, each consisting of samples from different environments. Although grain size and this strong pollution alter the study of REE as environmental indicators, it is possible to recognise groups of samples with a common origin or to identify the surface extent of a given pollution peak.

Aurochs roamed along the SW coast of Andalusia (Spain) during Late Pleistocene.

In the Iberian Peninsula the fossil record of artiodactyls spans over 53 million years. During the Pleistocene, wild cattle species such as Bison and especially Bos became common. In Late Pleistocene, the aurochs (Bos primigenius) was widespread and the only bovine living along the large river valleys of southern Iberia. Although commonly found in fossil sites and especially in cave bone assemblages, the trace fossil record of aurochs was known worldwide only from the Holocene. Large bovine and roe deer/caprine tracks were found in at least five horizons of the early Late Pleistocene (MIS 5) beach and eolian deposits of Cape Trafalgar (Cadiz Province, South of Spain). The large bovine tracks are formally described as Bovinichnus uripeda igen. et isp. nov. and compared with the record of aurochs tracks, large red deer tracks and steppe bison biogeographical distribution in Iberia. Aurochs were the most likely producers of the newly described Trafalgar Trampled Surface (TTS) and some of the large artiodactyl tracks in the Matalascañas Trampled Surface, representing the oldest aurochs track record known. This new evidence, together with comparisons with the record of possible aurochs tracks in the Mid-Late Pleistocene coastal deposits from the Asperillo cliff section in Matalascañas (Huelva Province, SW Spain) and bone assemblages known in Gibraltar, point to a recurrent use of the coastal habitat by these large artiodactyls in SW Iberia.

Cocoa (Theobroma cacao L.) Seed-Derived Peptides Reduce Blood Pressure by Interacting with the Catalytic Site of the Angiotensin-Converting Enzyme.

This study aimed at determining the effect of cocoa proteins (CP) on the blood pressure, using in silico, in vitro and in vivo approaches. The in silico assay showed 26 Criollo cocoa peptides with alignment in the Blast® analysis. Peptide sequences ranged from 6 to 16 amino acids, with molecular weight ranging from 560.31 to 1548.76 Da. The peptide sequences LSPGGAAV, TSVSGAGGPGAGR, and TLGNPAAAGPF showed the highest theoretical affinity with -8.6, -5.0, and -10.2 kcal/mol, for the angiotensin-converting enzyme (ACE), renin, and angiotensin II type 1 receptor (AT1-R), respectively. The Criollo CP hydrolysates (CPH) presented in vitro ACE inhibitory activity with an IC50 value of 0.49 mg/mL. Furthermore, the orogastric administration of 150 mg CP/kg/day in rats fed a high-fat (HF) diet (HF + CP group) showed a significant decrease in systolic blood pressure (SBP) by 5% (p < 0.001) and diastolic blood pressure (DBP) by 7% (p < 0.001) compared with the HF group. The human equivalent dose (HED) of CP for an adult (60 kg) is 1.45 g per day. These results suggest that the consumption of CP could reduce blood pressure by blocking ACE, and could be used as an ingredient in the elaboration of antihypertensive functional foods.

First tracks of newborn straight-tusked elephants (Palaeoloxodon antiquus).

Tracks and trackways of newborns, calves and juveniles attributed to straight-tusked elephants were found in the MIS 5 site (Upper Pleistocene) known as the Matalascañas Trampled Surface (MTS) at Huelva, SW Spain. Evidence of a snapshot of social behaviour, especially parental care, can be determined from the concentration of elephant tracks and trackways, and especially from apparently contemporaneous converging trackways, of small juvenile and larger, presumably young adult female tracks. The size frequency of the tracks enabled us to infer body mass and age distribution of the animals that crossed the MTS. Comparisons of the MTS demographic frequency with the morphology of the fore- and hind limbs of extant and fossil proboscideans shed light into the reproductive ecology of the straight-tusked elephant, Palaeloxodon antiquus. The interdune pond habitat appeared to have been an important water and food resource for matriarchal herds of straight-tusked elephants and likely functioned as a reproductive habitat, with only the rare presence of adult and older males in the MTS. The preservation of this track record in across a paleosol surface, although heavily trampled by different animals, including Neanderthals, over a short time frame, permitted an exceptional view into short-term intraspecific trophic interactions occurring in the Last Interglacial coastal habitat. Therefore, it is hypothesized that Neanderthals visited MTS for hunting or scavenging on weakened or dead elephants, and more likely calves.

Sarcoidosis: An FP's primer on an enigmatic disease.

Management includes ruling out alternate diagnoses, identifying occult/overt organ involvement, determining treatment, and recognizing worrisome features.

The burden of hypertension in Ecuador: a systematic review and meta-analysis.

Hypertension is a major risk factor of cardiovascular diseases, which occurrence has increased consistently worldwide. With this in mind, this review was designed to evaluate the prevalence of hypertension in Ecuador. We systematically searched publications in Medline, Cumulative Index of Nursing and Allied Health Literature, Cochrane Database, and Ibero-America electronic databases for articles published through September 2019 and reporting the prevalence of hypertension in Ecuador. Selected data were subjected to meta-analysis, and pooled prevalence and their 95% (95% CI) were calculated. Seventeen articles have been selected according to the inclusion/exclusion criteria of the study. The overall estimate of the pooled prevalence of hypertension was 35.8% (CI: 31.3-38.4). Most importantly, the prevalence of hypertension increased markedly with age and obesity. Pooled estimates for the four age subdivisions (<30 years), (≥30 and ≤50 years), (>50 and ≤60 years) and (>60 years) were 9.4% (CI: 7.3-11.5), 22.0% (CI: 19.0-25.0), 26.1% (22.2-30.0) and 48.7% (CI: 45.4-52.0), respectively. Moreover, the pooled estimate of subjects with BMI ≥ 30 kg/m2 (57.7%, CIs: 45.6-69.8) was markedly higher than those with BMI < 30 kg/m2 (30.4%, CI: 23.3-38.4). Although limited, available data reported higher rates of hypertension in Afro-Ecuadorians than other ethnicities. This study underlines a high prevalence of hypertension in adults nationwide, but mostly in elderly and obese individuals. The magnitude of this burden emphasizes the need for robust and targeted interventions to control hypertension, and ultimately reverse the trend of cardiovascular diseases.

Prevalence of stunting and obesity in Ecuador: a systematic review.

OBJECTIVE: In low- and middle-income countries, undernutrition remains a major risk factor for child growth retardation. In addition, the emergence of obesity in recent years is adding another public health concern in that both stunting and obesity are associated with serious adverse health consequences. This review was designed to evaluate the prevalence of stunting and obesity in Ecuador. DESIGN: Electronic databases were searched for articles published through February 2018 reporting the prevalence of stunting and/or obesity. Selected data were subjected to meta-analysis and pooled prevalence and their 95 percentiles (95 % CI) were calculated. SETTING: Studies were identified in Medline, Web of Science, CINAHL, Cochrane Database and Ibero-America databases. PARTICIPANTS: Population of Ecuador. RESULTS: Twenty-three articles were selected according to the inclusion/exclusion criteria of the study. The estimate of pooled prevalence of stunting was 23·2 % (95 % CI 23·3, 23·5) in preschoolers (age < 5 years), but was markedly higher in indigenous and rural communities. Pooled prevalence of obesity was 8·1 % (95 % CI 6·9, 9·3), 10·7 % (95 % CI 9·6, 11·7) and 10·5 % (95 % CI 9·2, 11·8) in preschoolers, school-age children (age: 5-11 years) and adolescent (age: 12-18 years), respectively. In adults (age ≥ 19 years), the rate of obesity was remarkably high as indicated by an overall estimate equal to 44·2 % (95 % CI 43·1, 45·4). CONCLUSIONS: This study underlines high levels of stunting among children and obesity among adults in Ecuador, both of which are not equally distributed among the population. The magnitude of this double burden emphasises the need for sustained and targeted interventions.

Cocoa (Theobroma cacao L.) Seed Proteins' Anti-Obesity Potential through Lipase Inhibition Using In Silico, In Vitro and In Vivo Models.

The aim of this study was to determine the pancreatic lipase (PL) inhibitory effect of cocoa protein (CP) hydrolysates (CPH) using in silico and in vitro approaches, and an in vivo high-fat diet (HF) obese rat model. The results showed better theoretical affinity on PL for cocoa peptides EEQR, GGER, QTGVQ, and VSTDVNIE released from vicilin and albumins (-6.5, -6.3, -6.2, and -6.1 kcal/mol, respectively). Absorption, distribution, metabolism, and excretion (ADMET) prediction showed the human intestinal absorption (HIA) capacity of orlistat and eight cocoa peptides, demonstrating that they presented a low probability of toxicity with values lower than 0.6, while the orlistat has a high probability of hepatotoxicity with a mean value of 0.9. CPH (degree of hydrolysis of 55%) inhibited PL with an IC50 (concentration needed to inhibit 50% of enzyme activity) value of 1.38 mg/mL. The intragastric administration of 150 mg CP/kg/day to rats increased total lipids and triglycerides excretion in feces, ranging from 11% to 15% compared to the HF-diet. The HF + CP-diet also significantly decreased (p < 0.05) the apparent rate of fat absorption compared with the HF group. These results suggest that CP has anti-obesity potential by inhibiting PL, thus helping to prevent the development of non-communicable diseases.

Sarcopenia y fragilidad como predictores de riesgo de muerte en adultos mayores con enfermedad renal crónica en hemodiálisis / Sarcopenia and fragility as predictors of risk of death in older adults with chronic kidney disease on hemodialysis

Introducción: Fragilidad y sarcopenia son variables que podrían influir decisivamente en el exitus del paciente con enfermedad renal crónica sometido a hemodiálisis. Objetivo: Determinar el riesgo de muerte de pacientes adultos mayores con enfermedad renal crónica en hemodiálisis que cursan con sarcopenia y fragilidad. Materiales y métodos: Se realizó una búsqueda sistemática de investigaciones publicadas entre los años del 2013 al 2018, en las bases de datos de acceso abierto especializadas en ciencias de la salud: Google Académico, Ebsco, PubMed, Redalyc, Scielo y Lilacs. Resultados: Luego de la búsqueda realizada, se recopilaron nueve estudios internacionales y un estudio nacional. No se ubicaron estudios locales. Conclusión: Sarcopenia y fragilidad se asocian con la peor condición nutricional y clínica, así como con el peor pronóstico en el paciente adulto mayor sometido a hemodiálisis. (AU)

Introduction: Fragility and sarcopenia could decisively influence the exitus of patients with chronic kidney disease undergoing hemodialysis. Objective: To determine the risk of death of elderly patients with chronic kidney disease on hemodialysis who present with sarcopenia and frailty. Materials and methods: A systematic search of research published between 2013 and 2018 was carried out in open access databases specializing in health sciences: Google Scholar, Ebsco, PubMed, Redalyc, Scielo and Lilacs. Results: After the search, nine international studies and one national study were compiled. No local studies were located. Conclusions: Sarcopenia and fragility are associated with a worse nutritional and clinical condition, as well as a worse prognosis in the elderly patient undergoing hemodialysis. (AU)

Silver and copper as pollution tracers in Neogene to Holocene estuarine sediments from southwestern Spain.

Estuaries are very sensitive ecosystems to human activities and the natural evolution of their drainage basins located upstream. Pollution derived from human activities, such as historical mining or recent industrial wastes, can significantly affect their environmental quality. This paper analyzes the silver and copper contents of four cores extracted in two estuaries of SW Spain. Its chronology and vertical evolution allow to differentiate the effects of several pollution episodes (natural, Roman, 19th-20th centuries) on its different sedimentary environments in the last 6 million years. Possible future applications are included in the fields of environmental management or even education.

Host plant defenses of black (Solanum nigrum L.) and red nightshade ( Solanum villosum Mill.) against specialist Solanaceae herbivore Leptinotarsa decemlineata (Say).

Black nightshade (Solanum nigrum, S. nigrum L.) and red nightshade ( Solanum villosum, S. villosum Mill.) are medicinal plants from the Solanaceae family that synthesize glycoalkaloids and other secondary metabolites. To recognize the potential insecticide activity of these compounds, leaf extracts (containing glycoalkaloid and methanol fractions) were tested for enzyme inhibition, antifeedant activity and toxicity. For in-vitro glutathione S-transferase (GST) inhibition activity, we used insecticide-resistant Colorado potato beetle, Leptinotarsa decemlineata ( L. decemlineata; Say) midgut and fat-body homogenate. In-vivo toxicity and the antifeedant activity were performed using larval bioassays. The methanol extracts had greater GST inhibitory activity compared to the glycoalkaloids, as well as greater 2nd instar larvae mortality and antifeedant activity. Furthermore, the green leaf volatile compound, cis-hex-3-enyl acetate, at the concentration of 5 ppm, caused 50% mortality of 2nd instar larvae. Our findings suggest the potential usefulness of S. nigrum and S. villosum extracts to control L. decemlineata.

Resistencia a la Fractura de Dientes Tratados Endodónticamente Obturados con Selladores Biocerámicos Versus Selladores Resinosos. Revisión Sistemática / Fracture Resistance of Endodontically Treated Teeth Obturated with Bioceramic Sealers and Epoxy Resin-Based Sealers. A Systematic Review

RESUMEN: El objetivo de este estudio fue determinar mediante la revisión de la literatura científica disponible cuál es el tipo de cemento sellador que proporciona mayor resistencia a la fractura en dientes tratados endodónticamente, los cementos a base de biocerámicos o los en base a resina epóxica. Se realizó una revisión sistemática de acuerdo a las bases de los estamentos de PRISMA, en las bases de datos Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. Se realizó la búsqueda a 10 años y se incluyeron sólo estudios in vitro. Se encontraron 202 artículos, luego se eliminaron los artículos duplicados y se excluyeron los estudios no atingentes por título y resúmenes, quedando ocho artículos que se revisaron a texto completo. En esta etapa se excluyeron dos estudios. Un total seis estudios fueron incluidos en esta revisión. De estos, ninguno encontró diferencia significativas entre cementos selladores a base de biocerámicos y a base de resina epóxica, en cuanto a resistencia a la fractura de los dientes tratados endodónticamente. Sin embargo, en 4 estudios los valores más altos encontrados de resistencia a la fractura estuvieron dados por los selladores en base a resina epóxica. Los artículos seleccionados, teniendo en consideración las limitaciones propias de los estudios in vitro, concluyen que en cuanto a resistencia a la fractura no hay diferencias significativas entre el uso de cementos selladores a base de biocerámicos y cementos selladores a base de resina epóxica en la obturación radicular de dientes tratados endodónticamente.

ABSTRACT: The objective of this study was to determine through the review of scientific literature, the type of sealer that provides the greatest resistance to fracture in endodontically treated teeth. Bioceramic sealer or epoxy resin based sealers were considered for this analysis. A systematic review was performed according to PRISMA, in the databases Medline, SciELO, Trip Database, LILACS, Web of Science, Cochrane. The search was carried out over the last 10 years, and only in vitro studies were included; 202 articles were found and subsequently, duplicate articles were eliminated, non-inferential studies by title and abstracts were excluded, leaving eight articles that were revised to full text. In this stage, two studies were excluded. In total, six studies were included in this review. Of these, none found significant difference between sealer cements based on bioceramics and based on epoxy resin, in terms of resistance to fracture of endodontically treated teeth. However, in 4 studies the highest found values of fracture resistance were given by sealers based on epoxy resin. Taking into account the limitations inherent to in vitro studies, this review concludes that in terms of fracture resistance, there are no significant differences between the use of sealer based on bioceramics and the based on epoxy resin in the root canal obturation.

Juegos especiales para mejorar el desempeño de tiradores juveniles en eventos de finales / Special games to improve the performance of youth shooters in finals events

RESUMEN Las modificaciones introducidas en los últimos años por la International Shooting Sport Federation, elevan las exigencias en la preparación de sus atletas. El artículo muestra una alternativa desplegada en la Academia Juvenil de tiro deportivo de la provincia de Villa Clara, resultado de una investigación en la Especialidad de esta disciplina deportiva desarrollada en la Universidad de Ciencias de la Cultura Física y el Deporte «Manuel Fajardo¼ de La Habana, Cuba. Su objetivo fue determinar la utilización de juegos especiales para el desarrollo de la preparación técnico-táctica y psicológica en los tiradores juveniles en los eventos de finales. Se combinaron métodos cuantitativos de nivel teórico como el análisis documental, de nivel empírico como la observación científica, entrevistas y un experimento; métodos estadísticos cuyos resultados se agruparon en tablas de frecuencias y talleres grupales de orden cualitativo. Entre sus principales resultados destacan el diagnóstico pre-competencia, la mejora de la preparación técnico-táctica y psicológica de los tiradores juveniles y sus resultados en eventos finales. La valoración por los usuarios y especialistas confirmó que este estudio trabajo puede replicarse en otras categorías de esta y otras modalidades deportivas.

ABSTRACT The modifications introduced in recent years by the International Shooting Sport Federation, raise the requirements in the preparation of its athletes. The article shows an alternative displayed in the Youth Academy of sports shooting in the province of Villa Clara, the result of a research in the specialty of this sports discipline developed at the University of Physical Culture and Sport Sciences «Manuel Fajardo¼ in Havana Cuba. Its objective was to determine the use of special games for the development of the technical-tactical and psychological preparation in the youth shooters in the final events. Quantitative methods of theoretical level were combined as documentary analysis, of empirical level such as scientific observation, interviews and an experiment; statistical methods whose results were grouped into frequency tables and qualitative group workshops. Among its main results are the pre-competition diagnosis, the improvement of the technical-tactical and psychological preparation of the juvenile shooters and their results in final events. The assessment by users and specialists confirmed that this study work can be replicated in other categories of this and other sports.

Corrosion of bare carbon steel as a passive sensor to assess moisture availability for biological activity in Atacama Desert soils.

Here we consider that the corrosion of polished bared metal coupons can be used as a passive sensor to detect or identify the lower limit of water availability suitable for biological activity in Atacama Desert soils or solid substrates. For this purpose, carbon steel coupons were deposited at selected sites along a west-east transect and removed at predetermined times for morphological inspection. The advantage of this procedure is that the attributes of the oxide layer (corrosion extent, morphology and oxide phases) can be considered as a fingerprint of the atmospheric moisture history at a given time interval. Two types of coupons were used, long rectangular shaped ones that were half-buried in a vertical position, and square shaped ones that were deposited on the soil surface. The morphological attributes observed by SEM inspection were found to correlate to the so-called humectation time which is determined from local meteorological parameters. The main finding was that the decreasing trend of atmospheric moisture along the transect was closely related to corrosion behaviour and water soil penetration. For instance, at the coastal site oxide phases formed on the coupon surface rapidly evolve into well-crystallized species, while at the driest inland site Lomas Bayas only amorphous oxide was observed on the coupons.