The influence of urban wastes on the interstitial water chemistry in coastal marine sediments of Cadiz Bay

The authors determined, with visual profiles, the concentration of nutrients (i.e. ammonia, nitrate, phosphate and silica), inorganic carbon and sulphate in the interstitial water of Cadiz Bay, as well as organic carbon in sediment, using samples from three stations on Sancti Petri sound. These three stations suffer from different contamination levels due to untreated urban wastewater. Our results show a degradation of the organic matter, principally in the first 30 cm of sediment. These concentration changes are important in the superficial water layer, indicating the efficiency of aerobic oxidation, the organic matter's principal mineralisation mechanism. Two stations, those nearest to the waste point, had the highest organic carbon concentrations in their sediment, as well as the highest vertical gradients of nutrient concentrations in their interstitial water. Sulphate reduction is the principal mechanism involved in the oxidation of organic matter. On the other hand, at the other station studied, with lower organic carbon levels, the gradients were smoother.Se han caracterizado los perfiles verticales en el agua intersticial de las concentraciones de nutrientes (amonio, nitrato, fosfato y silicato), carbono inorgánico y sulfato, así como de carbono orgánico en el sedimento en tres estaciones del caño de Sancti Petri, sujetas a distinto grado de contaminación por vertidos urbanos sin depurar. Analizando globalmente las variaciones con la profundidad de las concentraciones de las distintas especies estudiadas, se puede afirmar que existe una degradación continuada de la materia orgánica, al menos, en los primeros 30 cm del sedimento. Esta hipótesis se encuentra reforzada por la propia disminución de la concentración de carbono orgánico en el sedimento con la profundidad. Estos cambios de concentración son especialmente acusados en la lámina de agua más superficial, poniendo de manifiesto la eficiencia de la oxidación aeróbica como mecanismo de mineralización de la materia orgánica. Las dos estaciones más próximas al vertido, que poseen concentraciones de carbono orgánico más elevadas en el sedimento, presentan también mayores gradientes verticales de concentración de nutrientes en el agua intersticial, y la sulfatorreducción adquiere una mayor importancia relativa como vía de oxidación de la materia orgánica. Por el contrario, en la estación situada en el extremo sur del caño, menos afectada por los aportes de materia orgánica, se observan gradientes más suaves.Instituto Español de Oceanografí

Factor analysis of linear alkylbenzene sulphonate (LAS) vertical distribution in coastal sediments of Cadiz Bay (southwest Spain)

El comportamiento del alquilbenceno lineal sulfonato (LAS) en los sistemas costeros no se conoce con precisión, y este conocimiento es aun menor si nos restringimos al compartimento sedimentario. En este trabajo se aplica un análisis factorial a los resultados obtenidos para distintas variables determinadas en tres estaciones, tanto en sedimento como en agua intersticial, con el objetivo de evaluar sus interrelaciones con el LAS. Las variables analizadas presentan dos modos principales de distribución con la profundidad en el compartimento sedimentario: lineal y/o exponencial. En casi todos los casos, el LAS se asocia a ambos modos de distribución, lo que indica que su concentración sufre una disminución con la profundidad, pero se produce de forma especialmente acusada en la capa superficial.Very little is known concerning the behaviour of linear alkylbenzene sulphonate (LAS) in coastal systems, and even less when we consider the sedimentary field only. In the present study, a factor analysis is applied to the results obtained for different variables at three stations, both in the sediment and in interstitial water, with the aim of evaluating their relationship with LAS. The variables analysed have two main types of distribution in the sedimentary area in relation to depth: linear and/or exponential. LAS is, in most cases, associated with both types of distribution, indicating that its concentration decreases with depth, especially in the surface layer.Instituto Español de Oceanografí

DIGITAL DIVIDE IN PERUVIAN HIGHER EDUCATION: A POST-PANDEMIC REVIEW

By early 2020, the COVID-19 pandemic paralyzed the world, with the origin being the Chinese city of Wuhan. By March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic.  The dire consequences of this disease were reflected in a historic global recession, and in the health field, SARS-CoV-2 had wreaked havoc, especially in the elderly, due to worse manifestations and higher mortality rates. As a result, most countries were able to curb the spread of the virus by imposing mandatory measures such as not leaving their homes and very strict timetables. Among the measures considered was the closure of educational institutions, including universities. At that time, there was a paradigm shift in the way educators had to change the way they taught classes by making use of various online platforms. Online, distance and continuing education learning became a panacea for this unprecedented global pandemic for both educators and students. In this review, a passage is made through the different scenarios experienced by the COVID-19 pandemic, taking into account several objectives such as: the COVID-19, and the case of universities, the educational transition: from face-to-face to virtuality, challenges and opportunities after the pandemic, and last but not least, how the Peruvian State, was able to cope with the pandemic of Covid-19, and the challenges that should continue to be considered after the pandemic

Risk Estimation and Value-of-Information Analysis for Three Proposed Genetic Screening Programs for Chronic Beryllium Disease Prevention

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75032/1/0272-4332.00009.pd

Novel approaches of nanoceria with magnetic, photoluminescent, and gas-sensing properties

The modification of CeO2 with rare-earth elements opens up a wide range of applications as biomedical devices using infrared emission as well as magnetic and gas-sensing devices, once the structural, morphological, photoluminescent, magnetic, electric, and gas-sensing properties of these systems are strongly correlated to quantum electronic transitions between rare-earth f-states among defective species. Quantitative phase analysis revealed that the nanopowders are free from secondary phases and crystallize in the fluorite-type cubic structure. Magnetic coercive field measurements on the powders indicate that the substitution of cerium with lanthanum (8 wt %), in a fluorite-type cubic structure, created oxygen vacancies and led to a decrease in the fraction of Ce species in the 3+ state, resulting in a stronger room-temperature ferromagnetic response along with high coercivity (160 Oe). In addition to the magnetic and photoluminescent behavior, a fast response time (5.5 s) was observed after CO exposure, indicating that the defective structure of ceria-based materials corresponds to the key of success in terms of applications using photoluminescent, magnetic, or electrical behaviors.Fil: Rocha, Leandro S.R.. Universidade Federal do São Carlos; BrasilFil: Amoresi, Rafael A.C.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Moreno, Henrique. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ramirez, Miguel A.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ponce, Miguel Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Foschini, Cesar R.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Longo, Elson. Universidade Federal do São Carlos; BrasilFil: Simões, Alexandre Z.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Isgur-Wise Functions from the Mit Bag Model

The Isgur-Wise functions for the ground state to ground state semileptonic decays involving $b \rightarrow c$ transitions are calculated from the (modified) MIT bag model. It is checked that the results for the decays $\overline{B} \rightarrow D l \overline\nu$ and $\overline{B} \rightarrow D^* l \overline\nu$ agree well with experiment. Predictions for the decays $\Lambda_b \rightarrow \Lambda_c l \overline\nu$, $\overline{B}_s \rightarrow D_s l \overline\nu$ and $\overline{B}_s \rightarrow D^*_s l \overline\nu$ are given and discussed.Comment: 12 pages (3 figures available upon request), LaTeX, TPJU - 9/9

Greater basal skeletal muscle AMPKalpha phosphorylation in men than in women: associations with anaerobic performance

This study was designed to investigate the association of gender, fibre type composition, and anaerobic performance with the basal skeletal muscle signalling cascades regulating muscle phenotype

Wire Marking Results in a Small but Significant Reduction in Avian Mortality at Power Lines: A BACI Designed Study

10 paginas, 4 figuras y 4 tablesBackground: Collision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published. Methodology/Principal Findings: We provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV-45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking. Conclusions: Our results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.We thank A. Garcıa Fernandez and M. Carrasco for their assistance during the field work. We also thank J. Camaño and J. Velasco of HENARSA, and the electric companies Iberdrola, Union Fenosa and Red Electrica de España for their cooperation. S. Young reviewed the English. RB was contracted within the project CGL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation and later supported by a postdoctoral grant from Junta de Comunidades de Castilla-La Mancha. C. Ponce, C. Palacın, CM and BM were supported by contracts CSICHENARSA. This study was carried out within the Preventive, corrective and compensatory measures to balance the impact of the M-50 and R-2 highways on the population of great bustards and other steppe-land birds in the Important Bird Area Talamanca-Camarma and the Site of Community Importance Cuenca de los rıos Jarama y Henares, supported by a contract HENARSA-CSIC. Additional financial support was provided by project GL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Increased PIO2 at exhaustion in hypoxia enhaces muscle activation and swifty relieves fatigue: a placebo or a PIO2 dependent effect?

To determine the level of hypoxia from which muscle activation (MA) is reduced during incremental exercise to exhaustion (IE), and the role played by PIO2 in this process, ten volunteers (21 ± 2 years) performed four IE in severe acute hypoxia (SAH) (PIO2 = 73 mmHg). Upon exhaustion, subjects were asked to continue exercising while the breathing gas mixture was swiftly changed to a placebo (73 mmHg) or to a higher PIO2 (82, 92, 99, and 142 mmHg), and the IE continued until a new exhaustion. At the second exhaustion, the breathing gas was changed to room air (normoxia) and the IE continued until the final exhaustion. MA, as reflected by the vastus medialis (VM) and lateralis (VL) EMG raw and normalized root mean square (RMSraw, and RMSNz, respectively), normalized total activation index (TAINz), and burst duration were 8–20% lower at exhaustion in SAH than in normoxia (P < 0.05). The switch to a placebo or higher PIO2 allowed for the continuation of exercise in all instances. RMSraw, RMSNz, and TAINz were increased by 5–11% when the PIO2 was raised from 73 to 92, or 99 mmHg, and VL and VM averaged RMSraw by 7% when the PIO2 was elevated from 73 to 142 mmHg (P < 0.05). The increase of VM-VL average RMSraw was linearly related to the increase in PIO2, during the transition from SAH to higher PIO2 (R2 = 0.915, P < 0.05). In conclusion, increased PIO2 at exhaustion reduces fatigue and allows for the continuation of exercise in moderate and SAH, regardless of the effects of PIO2 on MA. At task failure, MA is increased during the first 10 s of increased PIO2 when the IE is performed at a PIO2 close to 73 mmHg and the PIO2 is increased to 92 mmHg or higher. Overall, these findings indicate that one of the central mechanisms by which severe hypoxia may cause central fatigue and task failure is by reducing the capacity for reaching the appropriate level of MA to sustain the task. The fact that at exhaustion in severe hypoxia the exercise was continued with the placebo-gas mixture demonstrates that this central mechanism has a cognitive component.This study was supported by a grant from the Ministerio de Educación y Ciencia of Spain (DEP2009-11638 and FEDER)