Combined use of the GGSFT data base and on Board Marine Collected Data to Model the Moho Beneath the Powell Basin, Antarctica

The Powell Basin is a small oceanic basin located at the NE end of the Antarctic Peninsula developed during the Early Miocene and mostly surrounded by the continental crusts of the South Orkney Microcontinent, South Scotia Ridge and Antarctic Peninsula margins. Gravity data from the SCAN 97 cruise obtained with the R/V Hespérides and data from the Global Gravity Grid and Sea Floor Topography (GGSFT) database (Sandwell and Smith, 1997) are used to determine the 3D geometry of the crustal-mantle interface (CMI) by numerical inversion methods. Water layer contribution and sedimentary effects were eliminated from the Free Air anomaly to obtain the total anomaly. Sedimentary effects were obtained from the analysis of existing and new SCAN 97 multichannel seismic profiles (MCS). The regional anomaly was obtained after spectral and filtering processes. The smooth 3D geometry of the crustal mantle interface obtained after inversion of the regional anomaly shows an increase in the thickness of the crust towards the continental margins and a NW-SE oriented axis of symmetry coinciding with the position of an older oceanic spreading axis. This interface shows a moderate uplift towards the western part and depicts two main uplifts to the northern and eastern sectors

Dialectical Interrelation Between: Problematic Situation, Real Problem, Scientific Problem, Object and Field, in the Investigation Design: A Necessary Reflection

All research responds to the need of solutions to a problem that directly or indirectly affects society. The development of the same largely certifies and determines the constant search for solutions. The main objective of the present study was to arrive at a clear conceptualization, as complete as possible, of some the most important terms that come up during an investigation design: Problematic Situation, Real Problem, Scientific Problem, and Object and Field, given the visible shortcomings observed in pre- and post-graduate theses when the research work is being developed and defended. The methodology consisted of basically developing a reflection around these terms (the vision that different authors have in this regard was very helpful), as well as the presentation of varied examples contributed to see the meaning of these important concepts more clearly. The study shows in a scientifically grounded way the achievement of the above. The way in which the presentation of the different concepts was handled removes any possibility of mistakes. Keywords: methodology scientific investigation, problem, object, field. Resumen Toda investigación parte del apremio en dar una respuesta a la solución de un problema que afecta de una manera directa o indirecta a la Sociedad. En gran medida, el propio desarrollo de la misma compulsa y determina esa constante búsqueda de soluciones. El objetivo principal del presente estudio fue llegar a una conceptualización clara, y lo más acabada posible, de algunos de los más importantes términos que se manejan durante el diseño de una investigación: Situación Problémica, Problema Real, Problema Científico, Objeto y Campo, dada las visibles falencias que se observan en tesistas de pre y postgrado a la hora de desarrollar y defender sus trabajos de investigación. La metodología consistió, básicamente, en desarrollar una reflexión en torno a estos términos; para lo cual resultó de gran ayuda la visión que tienen diferentes autores al respecto; así como, la exposición de variados ejemplos contribuyó a ver más definidamente el significado de estos importantes conceptos. El estudio muestra de forma científicamente fundamentada el logro de lo anterior. La forma en que se maneja la presentación de los diferentes conceptos aleja toda posibilidad de equívocos. Palabras clave: metodología investigación científica, problema, objeto, campo

Conservation Status of the American Horseshoe Crab, (Limulus Polyphemus): A Regional Assessment

Horseshoe crabs have persisted for more than 200 million years, and fossil forms date to 450 million years ago. The American horseshoe crab (Limulus polyphemus), one of four extant horseshoe crab species, is found along the Atlantic coastline of North America ranging from Alabama to Maine, USA with another distinct population on the coasts of Campeche, Yucatán and Quintana Roo in the Yucatán Peninsula, México. Although the American horseshoe crab tolerates broad environmental conditions, exploitation and habitat loss threaten the species. We assessed the conservation status of the American horseshoe crab by comprehensively reviewing available scientific information on its range, life history, genetic structure, population trends and analyses, major threats, and conservation. We structured the status assessment by six genetically-informed regions and accounted for sub-regional differences in environmental conditions, threats, and management. The transnational regions are Gulf of Maine (USA), Mid-Atlantic (USA), Southeast (USA), Florida Atlantic (USA), Northeast Gulf of México (USA), and Yucatán Peninsula (México). Our conclusion is that the American horseshoe crab species is vulnerable to local extirpation and that the degree and extent of risk vary among and within the regions. The risk is elevated in the Gulf of Maine region due to limited and fragmented habitat. The populations of horseshoe crabs in the Mid-Atlantic region are stable in the Delaware Bay area, and regulatory controls are in place, but the risk is elevated in the New England area as evidenced by continuing declines understood to be caused by over-harvest. The populations of horseshoe crabs in the Southeast region are stable or increasing. The populations of horseshoe crabs in the Florida Atlantic region show mixed trends among areas, and continuing population reductions at the embayment level have poorly understood causes. Within the Northeast Gulf of Mexico, causes of population trends are poorly understood and currently there is no active management of horseshoe crabs. Horseshoe crabs within México have conservation protection based on limited and fragmented habitat and geographic isolation from other regions, but elevated risk applies to the horseshoe crabs in the Yucatán Peninsula region until sufficient data can confirm population stability. Future species status throughout its range will depend on the effectiveness of conservation to mitigate habitat loss and manage for sustainable harvest among and within regions

Conservation Status of the American Horseshoe Crab, (Limulus Polyphemus): A Regional Assessment

Horseshoe crabs have persisted for more than 200 million years, and fossil forms date to 450 million years ago. The American horseshoe crab (Limulus polyphemus), one of four extant horseshoe crab species, is found along the Atlantic coastline of North America ranging from Alabama to Maine, USA with another distinct population on the coasts of Campeche, Yucatán and Quintana Roo in the Yucatán Peninsula, México. Although the American horseshoe crab tolerates broad environmental conditions, exploitation and habitat loss threaten the species. We assessed the conservation status of the American horseshoe crab by comprehensively reviewing available scientific information on its range, life history, genetic structure, population trends and analyses, major threats, and conservation. We structured the status assessment by six genetically-informed regions and accounted for sub-regional differences in environmental conditions, threats, and management. The transnational regions are Gulf of Maine (USA), Mid-Atlantic (USA), Southeast (USA), Florida Atlantic (USA), Northeast Gulf of México (USA), and Yucatán Peninsula (México). Our conclusion is that the American horseshoe crab species is vulnerable to local extirpation and that the degree and extent of risk vary among and within the regions. The risk is elevated in the Gulf of Maine region due to limited and fragmented habitat. The populations of horseshoe crabs in the Mid-Atlantic region are stable in the Delaware Bay area, and regulatory controls are in place, but the risk is elevated in the New England area as evidenced by continuing declines understood to be caused by over-harvest. The populations of horseshoe crabs in the Southeast region are stable or increasing. The populations of horseshoe crabs in the Florida Atlantic region show mixed trends among areas, and continuing population reductions at the embayment level have poorly understood causes. Within the Northeast Gulf of Mexico, causes of population trends are poorly understood and currently there is no active management of horseshoe crabs. Horseshoe crabs within México have conservation protection based on limited and fragmented habitat and geographic isolation from other regions, but elevated risk applies to the horseshoe crabs in the Yucatán Peninsula region until sufficient data can confirm population stability. Future species status throughout its range will depend on the effectiveness of conservation to mitigate habitat loss and manage for sustainable harvest among and within regions

Key Action Extraction for Learning Analytics

Proceedings of: 7th European Conference on Technology Enhanced Learning (EC-TEL 2012): 21st Century Learning for 21st Century Skills. Saarbrücken, Germany, September 18-21, 2012.Analogous to keywords describing the important and relevant content of a document we extract key actions from learners' usage data assuming that they represent important and relevant parts of their learning behaviour. These key actions enable the teachers to better understand the dynamics in their classes and the problems that occur while learning. Based on these insights, teachers can intervene directly as well as improve the quality of their learning material and learning design. We test our approach on usage data collected in a large introductory C programming course at a university and discuss the results based on the feedback of the teachers.Work partially funded by the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement no 231396 (ROLE project), the Learn3 project (TIN2008-05163/TSI), the eMadrid project (S2009/TIC-1650), and the Acci´on Integrada DE2009-0051.Publicad

FECUNDIDAD DE «CHIOCHÍO» Psectrogaster rutiloides (PISCES: CURIMATIDAE) EN UCAYALI, PERÚ.

Studies on the potential fecundity of chiochío, Psectrogaster rutiloides, are scarce despite this is one of the main fish species for small scale commercial and subsistence fishing catch in the Ucayali basin (Peru). A total of 74 female specimens on maturity stage IV were collected in October and November 2009. Total length, body weight, and gonad weight were recorded, and fecundity was assessed through the number of oocytes by the gravimetric method. Body length and weight were 15.2 ± 1.9 cm and 68.5 ± 24.7 g respectively, and the weight of gonads was 12.5 ± 5.3 g. The estimate number of oocytes was 45 058 ± 20 770. The relative fecundity varied from 1194 to 6619 oocytes per cm of body length, from 302 to 1202 oocytes per gram of body weight, and from 2654 to 8739 oocytes per gram of gonad weight. The regression analysis showed that gonad weight is a suitable predictor of the fecundity in this species.Estudios sobre el potencial de fecundidad del chiochío, Psectrogaster rutiloides, son escasos pese a ser una de las principales especies en la pesca semicomercial y de subsistencia para consumo humano de la cuenca del Ucayali, Perú. Se colectaron 74 hembras en estadio de madurez IV en octubre y noviembre de 2009. Se midió la longitud total, se registró el peso corporal y el peso de las gónadas y se determinó el número de ovocitos por el método gravimétrico. La talla y peso corporal fue de 15.2 ± 1.9 cm y 68.5 ± 24.7 g, respectivamente, y el peso de las gónadas fue de 12.5 ± 5.3 g. El número estimado de ovocitos fue de 45 058 ± 20 770. La fecundidad relativa varió entre 1194 y 6619 ovocitos por cm de talla, entre 302 y 1202 ovocitos por gramo de peso corporal, y entre 2654 y 8739 ovocitos por gramo de gónadas. El análisis de regresión indica que el peso de las gónadas es un buen elemento para estimar la fecundidad en esta especie

When LEP and Tevatron combined with WMAP and XENON100 shed light on the nature of Dark Matter

Recently, several astrophysical data or would-be signals has been observed in different dark-matter oriented experiments. In each case, one could fit the data at the price of specific nature of the coupling between the Standard Model (SM) particles and a light Dark Matter candidate: hadrophobic (INTEGRAL, PAMELA) or leptophobic (WMAP Haze, dijet anomalies of CDF, FERMI Galactic Center observation). In this work, we show that when one takes into account the more recent LEP and Tevatron analysis, a light thermal fermionic Dark Matte (\lesssim 10 GeV) that couples to electrons is mainly ruled out if one combines the analysis with WMAP constraints. We also study the special case of scalar dark matter, using a mono-photon events simulation to constrain the coupling of dark matter to electron.Comment: 8 pages, 6 figure

EFFECT OF VARIOUS LEVELS OF DIGESTIBLE ENERGY AND PROTEIN IN THE DIET ON THE GROWTH OF “GAMITANA” (COLOSSOMA MACROPOMUM) CUVIER 1818

Se llevó a cabo un experimento factorial para examinar el efecto de la interacción de dos niveles de proteína (25 y 35%) y tres niveles de energía digestible (2.3, 2.5 y 2.7 kcal/ g de alimento) en la dieta sobre la ganancia de peso (GP), conversión alimenticia (CA), energía retenida (ER) y el cociente de eficiencia proteica (REP) en la gamitana (Colossoma macropomum). En la composición de las dietas se empleó harina de anchoveta y harina de torta de soya como fuentes de proteína y maíz amarillo duro, subproducto de trigo y subproducto de cervecería como fuentes de energía. Se encontraron interacciones altamente significativas (p<0.01) entre la energía digestible y la proteína. En las dietas con 25% de proteína, el incremento del nivel de energía digestible mejoró significativamente la GP, CA, ER y la REP, siendo la mejor respuesta con 2.7 kcal/g. Sin embargo, para el nivel de 35% de proteína, solo el nivel de 2.7 kcal/g influyó significativamente sobre el comportamiento productivo de la gamitana. Se concluye que la gamitana obtuvo mejor rendimiento cuando fue alimentada con una dieta de 2.7 kcal/g de energía digestible y 25 % de proteína.A factorial experiment was conducted to evaluate the effect of diets with two levels of protein (25 and 35%) and three levels of digestible energy (2.3, 2.5, and 2.7 kcal/g) on the “gamitana” Colossoma macropomum in terms of body weight gain (WG), food conversion (FC), retained energy (RE), and protein efficiency ratio (PER). Diets contained anchovy and soybean meal as protein sources, and yellow corn, wheat bran, and brewery bran as energy sources. There were highly significant interactions (p<0.01) between protein concentration and digestible energy on the “gamitana” growth. In diets with 25% protein, the increase of digestible energy significantly enhanced WG, FC, RE, and PER, where the level of 2.7 kcal/g had the best performance. However, in diets with 35% protein, only the 2.7 kcal/g level showed good results. It can be concluded that the best response was obtained with a diet containing 2.7 kcal of energy digestible/g and 25% protein

Silicon-Rich Oxide Obtained by Low-Pressure Chemical Vapor Deposition to Develop Silicon Light Sources

Off stoichiometric silicon oxide, also known as silicon-rich oxide (SRO), is a light-emitting material that is compatible with silicon technology; therefore, it is a good candidate to be used as a light source in all-silicon optoelectronic circuits. The SRO obtained by low-pressure chemical vapor deposition (LPCVD) has shown the best luminescent properties compared to other techniques. In spite of LPCVD being a simple technique, it is not a simple task to obtain SRO with exact silicon excess in a reliable and repetitive way. In this work, the expertise obtained in our group to obtain SRO by LPCVD with precise variation is presented. Also, the characteristics of this SRO obtained in our group are revised and discussed. It is demonstrated that LPCVD is an excellent technique to obtain single layers and multilayers of nanometric single layers with good characteristics

Calidad de vida relacionada a la salud bucal en niños peruanos con caries de infancia temprana severa

Evaluar la percepción parental sobre la calidad de vida relacionada a la salud bucal en niños con caries de infancia temprana severa de un instituto de salud peruano. Método: Se realizó un estudio observacional, analítico y transversal, en 200 niños de 3 a 5 años de edad, sin caries y con caries de infancia temprana severa (CIT-S) escogidos aleatoriamente. El instrumento aplicado por un encuestador calibrado fue la versión peruana del cuestionario ECOHIS (P-ECOHIS) y el índice ceo-s. La distribución normal fue determinada con Kolmogorov – Smirnov, también se aplicó la prueba estadística U de Mann-Whitney. Resultados: El puntaje total del ECOHIS es mayor en los niños con CIT-S comparado con los niños sin caries, con una diferencia estadísticamente significativa (p<0.05). Conclusión: La percepción parental sobre la calidad de vida relacionada a la salud bucal fue negativamente afectada por la caries de infancia temprana severa de los niños de un instituto de salud peruano