Optical altimeter receiver systems study and design for a spaceborne laser altimeter

Design and specifications for optical altimeter receiver system

On the Stability of Compactified D=11 Supermembranes

We prove D=11 supermembrane theories wrapping around in an irreducible way over $S^{1} \times S^{1}\times M^{9}$ on the target manifold, have a hamiltonian with strict minima and without infinite dimensional valleys at the minima for the bosonic sector. The minima occur at monopole connections of an associated U(1) bundle over topologically non trivial Riemann surfaces of arbitrary genus. Explicit expressions for the minimal connections in terms of membrane maps are presented. The minimal maps and corresponding connections satisfy the BPS condition with half SUSY.Comment: 15 pages, latex. Added comments in conclusions and more reference

tutorial multimedia para la formación de competencias en el uso del computador dirigido a las docentes de educación inicial

The present study was adjusted in the positivist paradigm, under a quantitative approach, supported by field research descriptive in the form of Special Project. The goal was to design a Multimedia Tutorial for Competenses Training in computer use. The study subjects were 45 teachers of early childhood education sector schools Nueva Segovia, Vicente Salias, Macario Yepez, Claret Community. For data collection was used  the survey technique and the instrument was a questionnaire dichotomous questions and response alternatives related to research. The validity was performed by expert judgment and for reliability carried out a test pilot and Kuder Richardson statistical calculation which is used in dichotomous items. The data were analyzed, interpreted and presented through graphs and frequency tables and percentages which casts the need to design a multimedia tutorial for skills training in computer use aimed at pre-school teachers, who despite not having the knowledge, skills and abilities to use the computer, hold the claim to incorporate as their own to integrate, strengthen and consolidate skills which, from the technological point of view, allow you to walk to the excellence of this first level of education.El presente estudio se ajustó en el paradigma positivista, bajo un enfoque cuantitativo, apoyado en una investigación de campo de carácter descriptivo bajo la modalidad de Proyecto Especial. El objetivo fue diseñar un Tutorial Multimedia para la Formación de Competencias en el Uso del Computador. Los sujetos de estudio  fueron 45 docentes de Educación Inicial de las escuelas del sector Nueva Segovia, Vicente Salías, Macario Yépez, Comunal Claret. Para la recolección de datos se empleó la técnica de la encuesta y el instrumento fue un cuestionario de  preguntas dicotómicas y alternativas de respuesta relacionadas a la investigación. La validez se realizó por medio del juicio de expertos y para la confiabilidad se llevó a cabo una prueba piloto y el cálculo estadístico Kuder Richardson el cual es utilizado en ítems dicotómicos. Los datos fueron analizados, interpretados y presentados a través de gráficos y cuadros de frecuencias y porcentajes lo cual  arrojo la necesidad  de diseñar  un tutorial multimedia para la formación de competencias en el uso del computador dirigido a docentes de educación inicial, quienes a pesar de no poseer el conocimiento, las habilidades y destrezas para el uso del computador, ostentan la pretensión de incorporarlo como propio para incorporar, fortalecer y consolidar competencias las cuales, desde el punto de vista  tecnológico,  permitirá caminar a la excelencia de este primer nivel educativo

Innate Immunity Provides Biomarkers of Health for Teleosts Exposed to Nanoparticles

In recent years, the unique properties of nanoparticles have fostered novel applications in various fields such as biology, pharmaceuticals, agriculture, and others. Unfortunately, their rapid integration into daily life has also led to environmental concerns due to uncontrolled release of nanoparticles into the aquatic environment. Despite increasing awareness of nanoparticle bioaccumulation in the aquatic environment, much remains to be learned about their impact on aquatic organisms and how to best monitor these effects. Herein, we provide the first review of innate immunity as an emerging tool to assess the health of fish following nanoparticle exposure. Fish are widely used as sentinels for aquatic ecosystem pollution and innate immune parameters offer sensitive and reliable tools that can be harnessed for evaluation of contamination events. The most frequent biomarkers highlighted in literature to date include, but are not limited to, parameters associated with leukocyte dynamics, oxidative stress, and cytokine production. Taken together, innate immunity offers finite and sensitive biomarkers for assessment of the impact of nanoparticles on fish health

Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties

We investigate a long-term (26 years, from 1987 to 2013) variability in the broad spectral line properties of the radio galaxy Arp 102B, an active galaxy with broad double-peaked emission lines. We use observations presented in Paper I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of observations performed in 2012--2013. To explore the BLR geometry, and clarify some contradictions about the nature of the BLR in Arp 102B we explore variations in the H$\alpha$ and H$\beta$ line parameters during the monitored period. We fit the broad lines with three broad Gaussian functions finding the positions and intensities of the blue and red peaks in H$\alpha$ and H$\beta$. Additionally we fit averaged line profiles with the disc model. We find that the broad line profiles are double-peaked and have not been changed significantly in shapes, beside an additional small peak that, from time to time can be seen in the blue part of the H$\alpha$ line. The positions of the blue and red peaks { have not changed significantly during the monitored period. The H$\beta$ line is broader than H$\alpha$ line in the monitored period. The disc model is able to reproduce the H$\beta$ and H$\alpha$ broad line profiles, however, observed variability in the line parameters are not in a good agreement with the emission disc hypothesis. It seems that the BLR of Arp 102B has a disc-like geometry, but the role of an outflow can also play an important role in observed variation of the broad line properties.Comment: 17 pages, Accepted for publication in A&

Ultra-short Period Binaries from the Catalina Surveys

We investigate the properties of 367 ultra-short period binary candidates selected from 31,000 sources recently identified from Catalina Surveys data. Based on light curve morphology, along with WISE, SDSS and GALEX multi-colour photometry, we identify two distinct groups of binaries with periods below the 0.22 day contact binary minimum. In contrast to most recent work, we spectroscopically confirm the existence of M-dwarf+M-dwarf contact binary systems. By measuring the radial velocity variations for five of the shortest-period systems, we find examples of rare cool-white dwarf+M-dwarf binaries. Only a few such systems are currently known. Unlike warmer white dwarf systems, their UV flux and their optical colours and spectra are dominated by the M-dwarf companion. We contrast our discoveries with previous photometrically-selected ultra-short period contact binary candidates, and highlight the ongoing need for confirmation using spectra and associated radial velocity measurements. Overall, our analysis increases the number of ultra-short period contact binary candidates by more than an order of magnitude.Comment: 12 pages, 12 figures, accepted Ap