On the void explanation of the Cold Spot

The integrated Sachs-Wolfe (ISW) contribution induced on the cosmic microwave background by the presence of a supervoid as the one detected by Szapudi et al. (2015) is reviewed in this letter in order to check whether it could explain the Cold Spot (CS) anomaly. Two different models, previously used for the same purpose, are considered to describe the matter density profile of the void: a top hat function and a compensated profile produced by a Gaussian potential. The analysis shows that, even enabling ellipticity changes or different values for the dark-energy equation of state parameter $\omega$, the ISW contribution due to the presence of the void does not reproduce the properties of the CS. Finally, the probability of alignment between the void and the CS is also questioned as an argument in favor of a physical connection between these two phenomena

The Exemption Status of the Bona Fide Pledgee of Unregistered Securities Under the Securities Act of 1933

The number of connections of photovoltaic (PV) to distribution network is increasing. Very few PV connection guidelines that distribution system operators (DSOs) can refer to have been found. This paper deals with network planning guidelines for distribution networks with PV. The paper aims to identify planning rules that are relatively easy to implement.QC 20140625</p

Design and validation of an instrument to assess motor creativity in adolescents

El objetivo fue diseñar y validar un instrumento de medición de la Creatividad Motriz (ICM) en adolescentes: test de una sola tarea que evalúa dicha variable y cuatro dimensiones, Fluidez, Flexibilidad, Imaginación y Originalidad, mediante la expresión corporal. 312 estudiantes de Educación Secundaria (11-16 años) fueron divididos en dos grupos para realizar dos tests independientes (test-1, test-2). 6 expertos en creatividad participaron en el proceso de validación. La fiabilidad se obtuvo a través de la concordancia inter-observador de los expertos mediante el Coeficiente de Correlación Interclase en los dos tests, obteniéndose valores casi perfectos en todos los casos (0.81-1.00). Se estudió la validez interna, de respuesta, de contenido y de constructo del instrumento, obteniéndose resultados totalmente favorables. El ICM se ha mostrado un instrumento adecuado y fácil de implementar para medir la Creatividad Motriz en adolescentes; variable muy importante dentro del ámbito de la Educación Física y el deporteThe goal was to design and validate a Motor Creativity Assessment Instrument (ICM) in adolescents: a single-task test that evaluates this variable, and four of its dimensions, Flow, Flexibility, Imagination and Originality, through body expression. Three hundred and twelve secondary students (11-16 years) were randomly divided in two groups to undertake two independent tests (test-1, test-2). Six experts on creativity participated in the validation process. The instrument’s reliability was obtained through the inter-observer agreement, using the Intraclass Correlation Coefficient on both tests, and obtaining scores almost perfect in all cases (0.81-1.00). Internal, response, content and construct validity were also assessed, obtaining positive results in all of them. The ICM has been proven an adequate, easy-to-implement instrument to assess motor creativity in adolescents; a very important variable in Physical Education and Spor

Exploring two-spin internal linear combinations for the recovery of the CMB polarization

We present a methodology to recover cosmic microwave background (CMB) polarization in which the quantity $P = Q+ iU$ is linearly combined at different frequencies using complex coefficients. This is the most general linear combination of the $Q$ and $U$ Stokes parameters which preserves the physical coherence of the residual contribution on the CMB estimation. The approach is applied to the internal linear combination (ILC) and the internal template fitting (ITF) methodologies. The variance of $P$ of the resulting map is minimized to compute the coefficients of the linear combination. One of the key aspects of this procedure is that it serves to account for a global frequency-dependent shift of the polarization phase. Although in the standard case, in which no global E-B transference depending on frequency is expected in the foreground components, minimizing $\left\langle |P|^2\right\rangle$ is similar to minimizing $\left\langle Q^2\right\rangle$ and $\left\langle U^2\right\rangle$ separately (as previous methodologies proceed), multiplying $Q$ and $U$ by different coefficients induces arbitrary changes in the polarization angle and it does not preserve the coherence between the spinorial components. The approach is tested on simulations, obtaining a similar residual level with respect to the one obtained with other implementations of the ILC, and perceiving the polarization rotation of a toy model with the frequency dependence of the Faraday rotation.Comment: 14 pages, 8 figures, 2 tables. Accepted for publication in MNRA

Searching for a dipole modulation in the large-scale structure of the Universe

Several statistical anomalies in the CMB temperature anisotropies seem to defy the assumption of a homogeneous and isotropic universe. In particular, a dipole modulation has been detected both in WMAP and Planck data. We adapt the methodology proposed by Eriksen et al. (2007) on CMB data to galaxy surveys, tracing the large-scale structure. We analyse the NRAO VLA Sky Survey (NVSS) data at a resolution of ~2 degrees for three different flux thresholds: 2.5, 5.0 and 10.0 mJy respectively. No evidence of a dipole modulation is found. This result suggests that the origin of the dipole asymmetry found in the CMB cannot be assigned to secondary anisotropies produced at redshifts around z = 1. However, it could still have been generated at redshifts higher or lower, such as the integrated Sachs-Wolfe effect produced by the local structures. Other all-sky surveys, like the infrared WISE catalogue, could help to explore with a high sensitivity a redshift interval closer than the one probed with NVSS.Comment: 6 pages, 2 figures. Some minor changes have been done from the original manuscript. This paper is accepted by MNRA

Comparación de la precisión de los Modelos Geopotenciales EGM96 y EGM08 en la zona del Caribe.

Recientemente fue publicado un nuevo modelo geopotencial global, el EGM08. Este modelo ha mostrado una notable mejoría en la calidad de sus tres fuentes de datos; las observaciones del movimiento perturbado de los satélites artificiales,la altimetría por satélite y la gravimetría terrestre, por lo que se ha conseguido mejorar su precisión. En Puerto Rico, nuestra área de estudio, encontramos que al comprar las diferencias de los incrementos de la ondulación del geoide geométrico (calculado con medidas de campo) con los valores de los incrementos de la ondulación del geoide obtenidos utilizando estos modelos geopotenciales globales, la precisión del EGM08 fue ± 0,029 metros mientras que la precisión del EGM96 fue ± 0,055 metros. Estos resultados demuestran que en nuestra región, el modelo EGM08 ha presentado una mejoría considerable sobre su predecesor el EGM96 al momento de determinar los valores de los incrementos de la ondulación del geoide. Abstract: Recently, the new global geopotential model, the EGM08 was published. This model has shown a marked improvement in the quality of its three sources of data; the observations of the disturbed motion of artificial satellites, satellite altimetry and terrestrial gravity, so it has improved its precision. In our study area, Puerto Rico, we found that when we compare the differences of the increments of the geometric geoid undulation (computed with field data) with the values of the increments of the geoid undulation obtained using these models, the EGM08 accuracy was ± 0,029 meters, while the EGM96 accuracy was ± 0,055 meters. These results confirm that in our region, the EGM08 model has presented a significant improvement over its predecessor the EGM96 when determining the values of the increments of the geoid undulation

The collection of amphibians from Madrid at the Museo Nacional de Ciencias Naturales and its utility in conservation

[EN] We present the revised catalogue of the amphibians deposited in the “Colección de Anfibios y Reptiles” of the Museo Nacional de Ciencias Naturales that have been collected in the Comunidad Autónoma of Madrid. It consists of 2272 records of 18 species, including all species present in Madrid except Hyla meridionalis. We evaluate the collection on the basis of the representation of the specimens collected in relation with: 1) the present distribution of each amphibian species in Madrid, considering the number of UTM 10x10 km grid cells represented in the collection in relation with the total number of grids occupied by each species in Madrid; 2) the number of intraspecific subunits that are relevant from a conservation perspective (subspecies or groups of populations that are differentiated on ecological or genetic grounds) that are represented in the collection. Representation values range from 0% (Hyla meridionalis) to 50% (Triturus alpestris). We also include information on the conservation status of some populations from historical collection sites and conclude that at least 10 breeding sites have disappeared as a consequence of human activities, with the subsequent local extinction of their associated amphibian populations. We have also documented the disappearance of some species from unaltered areas. Finally, we discuss the utility of scientific collections in facing practical aspects of the management and conservation of endangered groups like amphibians.[ES] Se presenta el catálogo revisado de los anfibios de la Colección de Anfibios y Reptiles del Museo Nacional de Ciencias Naturales colectados en la Comunidad de Madrid. En total, consta de 2272 entradas correspondientes a 18 especies, que incluyen todas las presentes en la Comunidad excepto Hyla meridionalis. Se valora la colección en función del grado de representatividad de los ejemplares de la colección en relación con: 1) la distribución actual de las especies de anfibios en Madrid, considerando el % de cuadrículas UTM de 10x10 km del total del área de distribución de cada especie que se encuentran representadas en la colección; 2) el número de unidades infraespecíficas relevantes desde el punto de vista de la conservación (subespecies o grupos de poblaciones diferenciados ecológica o genéticamente) representados en la colección para cada especie. Los valores de representatividad obtenidos oscilan entre el 0% (Hyla meridionalis) y el 50% (Triturus alpestris). Además, se aporta información acerca de algunas de las poblaciones asentadas en los lugares de colecta históricos, lo que permite concluir que al menos 10 puntos de reproducción han desaparecido durante los últimos años como resultado de la actividad humana, con la consiguiente extinción local de esas poblaciones de anfibios. Por otro lado, en ciertos casos también se ha documentado la desaparición de especies en áreas aparentemente inalteradas. Finalmente, se discute la utilidad de las colecciones museológicas para afrontar aspectos prácticos relacionados con la gestión y conservación de grupos amenazados como los anfibios.El trabajo de IMS estáfinanciado por una beca predoctoral MNCN-CSIC-CAM.Peer reviewe

Low-density colloid centrifugation removes bacteria from boar semen doses after spiking with selected species

[EN] Single-layer centrifugation (SLC) with a low-density colloid is an efficient method for removing contaminating microorganisms from boar semen while recovering most spermatozoa from the original sample. This study tested the performance of this technique, using 50-ml tubes, by spiking commercial semen doses prepared without antibiotics with selected bacterial species followed by storage at 17 °C. The doses were spiked up to 102/ml CFU (colony forming units) of the bacteria Burkholderia ambifaria, Pseudomonas aeruginosa, and Staphylococcus simulans. The semen was processed by SLC (15 ml of sample and 15 ml of colloid) with the colloid Porcicoll at 20% (P20) and 30% (P30), with a spiked control (CTL) and an unspiked control (CTL0), analyzing microbiology and sperm quality on days 0, 3 and 7. SLC completely removed B. ambifaria and S. simulans, considerably reducing P. aeruginosa and overall contamination (especially P30, ∼104 CFU/ml of total contamination on day 7, median). Sperm viability was lower in P20 and P30 samples at day 0, with higher cytoplasmic ROS. Still, results were similar in all groups on day 3 and reversed on day 7, indicating a protective effect of SLC (possibly directly by removal of damaged sperm and indirectly because of lower bacterial contamination). Sperm chromatin was affected by the treatment (lower DNA fragmentation and chromatin decondensation) and storage (higher overall condensation on day 7 as per chromomycin A3 and monobromobimane staining). In conclusion, SLC with low-density colloids can remove most bacteria in a controlled contamination design while potentially improving sperm quality and long-term storage at practical temperatures.S