ESTIMAÇÃO DA CONFIABILIDADE EM MEDIÇÕES DE DOIS ITENS: O COEFICIENTE ANGOFF-FELDT

En la actualidad el uso de medidas breves en la evaluación psicológica se extiende con rapidez, pero en muchas ocasiones el análisis de la confiabilidad de sus puntajes se ve limitado por las condiciones que deben superarse para utilizar determinados coeficientes (p.e., el coeficiente α). El cumplimiento del modelo tau-equivalente es una de las más importantes que exige el coeficiente α y al no alcanzarse, la estimación puede estar sesgada. El objetivo de este artículo es presentar el coeficiente Angoff-Feldt (rAF) para la estimación de la confiabilidad, que pueda ser usado en medidas congenéricas, es decir, que no cumplan con las exigencias del coeficiente α (p.e., modelo tau-equivalente). Si bien el rAF se pensó inicialmente para dos mitades congenéricas, en el artículo se presenta la aplicación para medidas de dos ítems, asumiendo que cada uno es una mitad. Se brindó un ejemplo sobre su utilidad, y se discute la posibilidad de implementar su uso. Nowadays, the use of brief measurements in psychological evaluations is extending rapidly, but many times the reliability analysis of the scores is limited by the conditions which must be overcome to use certain coefficients (e.g. α coefficient). The compliance of the tau equivalent measurement model is one of the most important the α coefficient demands, and as it is not achieved, the estimate may be biased. The aim of this paper is to present the Angoff-Feldt (rAF) coefficient for reliability estimate, to be used in congeneric measures, that is, those that do not comply with the demands of the α coefficient (e.g. tau equivalent model). Although rAF was initially thought for two congeneric halves, this paper presents the application for the measurement of two items, assuming each is a half. An example of its usefulness is provided and the possibility of implementing its use discussed. Hoje em dia o uso de medidas breves na avaliação psicológica se desenvolve cada vez mais rápido, mas em muitas ocasiões a análise de confiabilidade de suas pontuações se limita pelas condições que devem superar-se para utilizar determinados coeficientes (p.e., o coeficiente α). O cumprimento do modelo tau-equivalente é uma das mais importantes que exige o coeficiente α e ao não se alcançar, a estimação pode ser um víeis. O objetivo deste artigo é apresentar o coeficiente Angoff-Feldt (rAF) para a estimação da confiabilidade, que possa ser usado em medidas congenéricas, ou seja, que não cumpram com as exigências do coeficiente α (p.e., modelo tau-equivalente). Enquanto o rAF inicialmente pensado para duas metades congenéricas, no artigo relata a aplicação para medidas de dois itens, assumindo que cada um é uma metade. Exemplifica-se sobre sua utilidade, e menciona-se a possibilidade de implementar seu uso

Impact of climate change on surface stirring and transport in the Mediterranean Sea

Understanding how climate change will affect oceanic fluid transport is crucial for environmental applications and human activities. However, a synoptic characterization of the influence of climate change on mesoscale stirring and transport in the surface ocean is missing. To bridge this gap, we exploit a high-resolution, fully coupled climate model of the Mediterranean basin using a Network Theory approach. We project significant increases of horizontal stirring and kinetic energies in the next century, likely due to increments of available potential energy. The future evolution of basin-scale transport patterns hints at a rearrangement of the main hydrodynamic provinces, defined as regions of the surface ocean that are well mixed internally but with minimal cross-flow across their boundaries. This results in increased heterogeneity of province sizes and stronger mixing in their interiors. Our approach can be readily applied to other oceanic regions, providing information for the present and future marine spatial planning.En prensa3,79

Structure and photoactivity for hydrogen production of CdS nanorods modified with In, Ga, Ag-In and Ag-Ga and prepared by solvothermal method

This work studies the variation in the photocatalytic properties of CdS derived from the insertion of In, Ga, Ag-In and Ag-Ga in the CdS lattice through solvothermal methodology. Solvothermal synthesis of CdS-M photocatalysts has been succesful for the insertion of Ga3þ, In3þ, Ga3þ/Agþ and In3þ/Agþ into the hexagonal crystal lattice of one-dimensional CdS. The insertion of In, Ga, Ag-In and Ag-Ga modifies the band gap and the relative position of EVB. CdS modified with In3þ or Ga3þ shows an increase in the band gap and upshift in the relative position of the valence band energy which leads to a low efficiency hydrogen production. The co-addition of Agþ-In3þ or Agþ-Ga3þ favours the insertion of Agþ ions into the CdS lattice with narrower band gap. Of all the co-substituted photocatalysts, the CdS-AgGa was the only one that showed a higher photoactivity with respect to the CdS. The increase in the photoactivity of the CdS-AgGa photocatalyst is related to the band gap narrowing and downshift in the relative position of the valence band energy which enhance their visible light absorption and potential for oxidation. The CdS-AgGa photocatalyst shows small segregation of metallic Ag nanoparticles at the surface which also assist in the photoactivity of the sample.publishe

Effects of fat and/or methionine hydroxy analog added to a molasses-urea-based supplement on ruminal and postruminal digestion and duodenal flow of nutrients in beef steers consuming low-quality lovegrass hay

Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molassesurea- based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass Eragrostis curvula: 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, NC); 2) molassesurea liquid supplement (U); 3) U containing (as-fed basis) 1.65% MHA (UM); 4) U containing (as-fed basis) 12% fat (UF); and 5) U containing (as-fed basis) 1.65% MHA and 12% fat (UMF). Total and forage OM intake (kg/d and as % of BW) increased (P \u3c 0.01) with molasses-urea, decreased (P ≤ 0.04) with MHA, and were not affected (P = 0.61) with fat supplementation. Total tract NDF digestibility increased (P = 0.01) with molasses-urea supplementation, and was less (P = 0.01) for fat than for nonfat supplementation. Total and microbial N flowing to the duodenum increased (P = 0.01) with molasses-urea supplementation. Although, total N flowing to duodenum was not affected (P = 0.27), microbial N decreased (P = 0.01), and nonammonia nonmicrobial N (NANMN) increased (P = 0.01) with fat supplementation. Extent of in situ OM and NDF digestibility at 96 h increased (P = 0.01) with molasses-urea supplementation, but were not affected (P ≥ 0.14) by either MHA or fat supplementation. Duodenal flow of total AA, essential AA, and nonessential AA increased (P ≤ 0.02) with molasses-urea supplementation. Total and nonessential serum AA concentration decreased (P \u3c 0.01) with molasses-urea supplementation. Total ruminal VFA concentration increased (P = 0.01) with molasses-urea supplementation, and was not affected (P ≥ 0.14) by MHA or fat supplementation. Fat can be used in molasses-urea liquid supplements for cattle consuming low-quality forage to increase energy intake without negatively affecting forage intake or characteristics of digestion. However, adding MHA did not further improve the response to urea supplementation of cattle consuming low-quality forage. Conversely, the inclusion of MHA on urea supplement decreased forage intake

Functional divergence in the role of N-linked glycosylation in smoothened signaling

The G protein-coupled receptor (GPCR) Smoothened (Smo) is the requisite signal transducer of the evolutionarily conserved Hedgehog (Hh) pathway. Although aspects of Smo signaling are conserved from Drosophila to vertebrates, significant differences have evolved. These include changes in its active sub-cellular localization, and the ability of vertebrate Smo to induce distinct G protein-dependent and independent signals in response to ligand. Whereas the canonical Smo signal to Gli transcriptional effectors occurs in a G protein-independent manner, its non-canonical signal employs Gαi. Whether vertebrate Smo can selectively bias its signal between these routes is not yet known. N-linked glycosylation is a post-translational modification that can influence GPCR trafficking, ligand responsiveness and signal output. Smo proteins in Drosophila and vertebrate systems harbor N-linked glycans, but their role in Smo signaling has not been established. Herein, we present a comprehensive analysis of Drosophila and murine Smo glycosylation that supports a functional divergence in the contribution of N-linked glycans to signaling. Of the seven predicted glycan acceptor sites in Drosophila Smo, one is essential. Loss of N-glycosylation at this site disrupted Smo trafficking and attenuated its signaling capability. In stark contrast, we found that all four predicted N-glycosylation sites on murine Smo were dispensable for proper trafficking, agonist binding and canonical signal induction. However, the under-glycosylated protein was compromised in its ability to induce a non-canonical signal through Gαi, providing for the first time evidence that Smo can bias its signal and that a post-translational modification can impact this process. As such, we postulate a profound shift in N-glycan function from affecting Smo ER exit in flies to influencing its signal output in mice

X-ray and weak lensing measurements of the mass profile of MS1008.1-1224: Chandra and VLT data

We analyse the Chandra dataset of the galaxy cluster MS1008.1-1224 to recover an estimate of the gravitating mass as function of the radius and compare these results with the weak lensing reconstruction of the mass distribution obtained from deep FORS1-VLT multicolor imaging. Even though the X-ray morphology is disturbed with a significant excess in the northern direction suggesting that the cluster is not in a relaxed state, we are able to match the two mass profiles both in absolute value and in shape within 1 sigma uncertainty and up to 1100 h50^-1 kpc. The recovered X-ray mass estimate does not change by using either the azimuthally averaged gas density and temperature profiles or the results obtained in the northern sector alone where the signal-to-noise ratio is higher.Comment: 5 pages. Accepted for publication in A&A Letter

Optimus: plataforma digital dedicada a la recomendaci?n y gesti?n de recolocaci?n de servicios de telefon?a m?vil pospago

En Lima Metropolitana, los clientes de telefon?a m?vil pospago no hacen uso de todos los beneficios adquiridos mediante contrato con las empresas operadoras, adem?s de verse envueltos en gestiones complejas para realizar solicitudes de recolocaci?n. Por ello, se identific? una oportunidad para implementar la plataforma digital B2C denominada Optimus, que permita evaluar sus necesidades, comparar la oferta comercial existente, recomendar la mejor opci?n de plan y gestionar su recolocaci?n. Para tal efecto, se plante? como objetivo determinar la factibilidad econ?mica y t?cnica del modelo de negocio, considerando dos fases estrat?gicas: la primera, de penetraci?n, con el objetivo de incrementar la cuota de mercado; y la segunda, de posicionamiento basado en liderazgo de costos. Realizada la investigaci?n de mercado, los resultados se?alaron que el 43% de las personas que conforman el mercado potencial estar?an dispuestas a pagar por los servicios de Optimus, con un ticket m?ximo de S/80,00. Finalmente, se evalu? la viabilidad econ?mica tomando en cuenta los escenarios pesimista, esperado y optimista, circunscritos a las variables de ingresos (precio, cantidad y volumen) y a diversos costos, en especial el de autorizaci?n de representatividad legal (carta poder), que genera gran impacto en el costo de ventas

Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing

Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action

International audienceIntegrated high-resolution maps of carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits. A new integrated approach to biodiversity is therefore needed. Here, we (a) present a new high-resolution map of global above- and below-ground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and (c) examine patterns of carbon–biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. The western Amazon Basin, Central Africa and Southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been greatly reduced are mostly found in the tropical Andes and central Sundaland. There is 38 and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12 and 21% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactnes

Recovery Signals of Rhodoliths Beds since Bottom Trawling Ban in the SCI Menorca Channel (Western Mediterranean)

One of the objectives of the LIFE IP INTEMARES project is to assess the impact of bottom trawling on the vulnerable benthic habitats of the circalittoral bottoms of the Menorca Channel (western Mediterranean), designated a Site of Community Importance (SCI) within the Natura 2000 network. The present study compares the epibenthic communities of four areas, subjected to different bottom trawl fishing intensity levels. The assignment of fishing effort levels was based on the fishing effort distribution in the area calculated from Vessel Monitoring System (VMS) data and the existence of two Fishing Protected Zones in the Menorca Channel. Biological samples were collected from 39 beam trawl stations, sampled during a scientific survey on April 2019. We compare the diversity, composition, and density of the epibenthic flora and fauna, together with the rhodoliths coverage and the morphology of the main species of rhodoliths of four areas subjected to different levels of bottom trawl fishing effort, including one that has never been impacted by trawling. Our results have shown negative impacts of bottom trawling on rhodoliths beds and the first signals of their recovery in areas recently closed to this fishery, which indicate that this is an effective measure for the conservation of this habitat of special interest and must be included in the management plan required to declare the Menorca Channel as a Special Area of Conservation.En prens