Cosmic variance of the galaxy cluster weak lensing signal

Intrinsic variations of the projected density profiles of clusters of galaxies at fixed mass are a source of uncertainty for cluster weak lensing. We present a semi-analytical model to account for this effect, based on a combination of variations in halo concentration, ellipticity and orientation, and the presence of correlated haloes. We calibrate the parameters of our model at the 10 per cent level to match the empirical cosmic variance of cluster profiles at M_200m=10^14...10^15 h^-1 M_sol, z=0.25...0.5 in a cosmological simulation. We show that weak lensing measurements of clusters significantly underestimate mass uncertainties if intrinsic profile variations are ignored, and that our model can be used to provide correct mass likelihoods. Effects on the achievable accuracy of weak lensing cluster mass measurements are particularly strong for the most massive clusters and deep observations (with ~20 per cent uncertainty from cosmic variance alone at M_200m=10^15 h^-1 M_sol and z=0.25), but significant also under typical ground-based conditions. We show that neglecting intrinsic profile variations leads to biases in the mass-observable relation constrained with weak lensing, both for intrinsic scatter and overall scale (the latter at the 15 per cent level). These biases are in excess of the statistical errors of upcoming surveys and can be avoided if the cosmic variance of cluster profiles is accounted for.Comment: 14 pages, 6 figures; submitted to MNRA

The kilogram: inertial or gravitational mass?

With the redefinition of the international system of units, the value of the Planck constant was fixed, similarly to the values of the unperturbed ground state hyperfine transition frequency of the Cs-133 atom and speed of light in vacuum. Theoretically and differently from the past, the kilogram is now explicitly defined as the unit of inertial mass. Experimentally, the kilogram is realized by atom count or the Kibble balance. We show that only the former method measures the inertial mass without assuming the universality of free fall. Under ordinary circumstances, the results obtained by the Kibble balance require the equivalence of inertial and gravitational mass. Therefore, the agreement between the two measures can be interpreted as a test of the equivalence principle

Estrategia pedag?gica para reducir la agresividad y el conflicto en las relaciones de convivencia del grado 604 de la Instituci?n Educativa Nuestra Se?ora del Carmen Miraflores, Guadalupe.

199 p. Recurso Electr?nicoEste proyecto es necesario para favorecer la cultura ciudadana en la escuela porque fortalece la autonom?a y autorregulaci?n de los estudiantes frente al manejo y la resoluci?n de conflictos escolares. Mediante mesas de conciliaci?n y de resoluci?n de conflictos es indispensable promover un proceso de toma de decisiones, cuyo objetivo sea manejar, gestionar, y resolver el conflicto entre pares, de manera que los estudiantes potencien valores tales como el respeto por la dignidad y los derechos humanos. As? mismo, se realiza un trabajo de identificaci?n de posibles casos de exclusi?n, violencia y enfrentamientos entre estudiantes, con los cuales se orientan; tambi?n se realizan talleres de formaci?n, en donde los estudiantes y padres de familia participan de manera focal, haciendo parte activa en el proceso. Teniendo en cuenta de que los conflictos son situaciones y procesos que suceden con regularidad, en las relaciones con los dem?s e incluso con nosotros mismos, por consiguiente configuran un algo productivo de aquello que se puede aprender en cuanto a desarrollar diferentes habilidades; encontrando diversos factores que influyan, directa o indirectamente en los comportamientos en el aula de clase. Palabras Claves: convivencia, violencia, conflicto, escuela, motivaci?n, resoluci?n, educaci?n, Problema, ni?o y comunidad.This project contributes to citizen?s culture at the school because strengthen the autonomy and self-regulation of students facing to manage and the resolution schoolchild conflicts. Through the conciliation tables and resolution conflicts we encourage a process of decision making, which objective is lead, manage, resolve, or give solution the conflict between pairs, such that of the students to boost the values like the respect for dignity and the human rights. In this way, carry out a identification work of possible cases of exclusion, violence, confrontation of students, who the work is oriented. Those in the trainer workshop are completed whit the students and parents in focal way where every actor is actively involved in the process. The conflicts are situations and process than happen with normalcy in relationship with others and even with ourselves. The fact is they treat them as if were wrong and, although sometimes they spend awful time, should look at them from a positive point of view. The conflicts are something productive where they can learn many things. This require learning how to manage them and develop several skills. Also have to take into account diverse factors that influence directly and indirectly in the conflict and their relationship with the school and the classroom. Keywords: coexistence, violence, conflict, school, motivation, resolution, education, issue, child, communit

Selective Breeding to Improve Productive and Reproductive Performances and Survivability of Indigenous Sakini Chicken

Indigenous chickens are quite popular in Family Poultry Production System (FPPS) in Nepal, but are constrained with their low productive performance. The present study evaluated the productive and reproductive performance of Sakini chicken in different filial generations and sexes. In addition, research also aimed at understanding the effect of generations on above performances. Initially, base populations (G-0) of Sakini were maintained by collecting eight weeks old birds from different agro-ecologial zones of Nepal. Performance of the birds of G-0 was evaluated based on weekly body weight (12-24 weeks), laying performance, fertility, hatchability, hatch weight and survivability. Selected birds of base population (G-0) were used to produce first (G-1), second (G-2) and third (G-3) generations through selective breeding in each generation. Similarly, body weights at hatching, 12 weeks, 16 weeks, 20 week and 24 weeks were significantly (p<0.001) improved from G0 to G3 and were also significantly (p<0.001) differ for sex (males were always heavier than females). Likewise, there was significant (p<0.05) improvement in egg production (per hen per year), age at first lay (days), body weight at sexual maturity, egg number and egg weight at 90 days of laying in progressive generations. Fertility, hatchability and survivability significantly (p<0.05) improved in selected generations in comparison to base population, whereas, no significant difference was obtained within the different selected population. Thus, indigenous Sakini chicken under this experiment performed better with respect to survivability, fertility and hatchability in later generations that provides ample scope of advancing selective breeding activities within the indigenous population in order to bring significant improvement in the overall productive performance of Sakini chicken in Nepal

Density functional theory calculations of the stress of oxidised (1 1 0) silicon surfaces

The measurement of the lattice-parameter of silicon by x-ray interferometry assumes the use of strain-free crystals. This might not be the case because surface relaxation, reconstruction, and oxidation cause strains without the application of any external force. In a previous work, this intrinsic strain was estimated by a finite element analysis, where the surface stress was modeled by an elastic membrane having a 1 N m(-1) tensile strength. The present paper quantifies the surface stress by a density functional theory calculation. We found a value exceeding the nominal value used, which potentially affects the measurement accuracy

Bayesian Probabilities and the Histories Algebra

We attempt a justification of a generalisation of the consistent histories programme using a notion of probability that is valid for all complete sets of history propositions. This consists of introducing Cox's axioms of probability theory and showing that our candidate notion of probability obeys them. We also give a generalisation of Bayes' theorem and comment upon how Bayesianism should be useful for the quantum gravity/cosmology programmes.Comment: 10 pages, accepted by Int. J. Theo. Phys. Feb 200

Parallel implementation of Artificial Neural Network training for speech recognition

In this paper we describe the implementation of a complete ANN training procedure using the block mode back-propagation learning algorithm for sequential patterns – such as the observation feature vectors of a speech recognition system – exploiting the high performance SIMD architecture of GPU using CUDA and its C-like language interface. We also compare the speed-up obtained implementing the training procedure only taking advantage of the multi-thread capabilities of multi-core processors. In our implementation we take into account all the peculiar aspects of training large scale sequential patterns, in particular, the re-segmentation of the training sentences, the block size for the feed-forward and for the back-propagation steps, and the transfer of huge amount of data from host memory to the GPU card. Our approach has been tested by training acoustic models for large vocabulary speech recognition tasks, showing a six times reduction of the time required to train real-world large size networks with respect to an already optimized implementation using the Intel MKL libraries. Thanks to these optimizations and to the support of the GPU, the training time for language having a huge set of training sentences (about one million for Italian) can be reduced from approximately a month to 5 days

Hamiltonians for a general dilaton gravity theory on a spacetime with a non-orthogonal, timelike or spacelike outer boundary

A generalization of two recently proposed general relativity Hamiltonians, to the case of a general (d+1)-dimensional dilaton gravity theory in a manifold with a timelike or spacelike outer boundary, is presented.Comment: 17 pages, 3 figures. Typos correcte