Changes in length and weight of milkfish fry preserved in formalin

Fry shrank immediately after they were preserved in formalin, but from the second week onwards shrinkage was almost nil. Fry in freshwater formalin solutions shrunk less than those in seawater formalin solutions. It is recommended that milkfish Chanos) fry be preserved in formalin solutions for 1 wk prior to length measurement and at least for 3 wks before determining body weight

Mine-risk Education in Ecuador: A Person-to-person Approach

“Explosive Mines Kill” is the message that the Organization of American States’ Acción Integral contra las Minas Antipersonal program wants to get across to communities living in mined areas in Ecuador. By taking an interpersonal approach to mine-risk education, the AICMA campaign advocates hope to raise awareness about the risks associated with anti-personnel mines and unexploded ordnance

CAMPO CONCEPTUAL ESTEQUIOMETR\ucdA DE LAS REACCIONES QU\ucdMICAS.PARTE II: EL TRABAJO DE LABORATORIO EN UN CURSO UNIVERSITARIO

Se presentan resultados de una investigaci\uf3n del desarrollo conceptual en un trabajo pr\ue1ctico referente al campo conceptual estequiometr\ueda de las reacciones qu\uedmicas (CC-ERQ), llevado a cabo desde la perspectiva de la teor\ueda de los campos conceptuales de Vergnaud (1990) con estudiantes de segundo semestre de Ingenier\ueda Civil de la Universidad Centroccidental Lisandro Alvarado (UCLA). El referente te\uf3rico plantea que el desarrollo cognitivo depende de situaciones problemas y conceptualizaciones. Las situaciones permiten que el estudiante explicite los invariantes operatorios (IO) que son las que atribuir\ue1n sentido a los conceptos. El prop\uf3sito fue evaluar el desarrollo conceptual del estudiante al explorar v\uednculos entre la estructura cognitiva y la estructura del campo conceptual construido desde la qu\uedmica, para luego describir niveles de conceptualizaci\uf3n. Se propone una metodolog\ueda que pretende favorecer el aprendizaje conceptual y procedimental a trav\ue9s de la inclusi\uf3n de la V epistemol\uf3gica de Gowin en los trabajos de laboratorio, utilizando la resoluci\uf3n de problemas como eje central del trabajo experimental. El dise\uf1o de la propuesta se bas\uf3 en una investigaci\uf3n de campo, con enfoque interpretativo. Las fuentes de informaci\uf3n fueron las producciones individuales y grupales, escritas y orales, generadas durante el desarrollo del laboratorio en tres (3) momentos fundamentales de la investigaci\uf3n. Los resultados confirman potencialidades de la teor\ueda para abordar estos v\uednculos, que se manifiestan en el uso de IO para enfrentar situaciones que demandan una conceptualizaci\uf3n, estas dan forma a representaciones del sistema qu\uedmico. Se dio cuenta de una evoluci\uf3n conceptual aceptable enmarcada en cuatro tipolog\uedas de representaci\uf3n del CC-ERQ: Perceptivo-Intuitivo, Formalista-Algor\uedtmico, Racionalista-Te\uf3rico y de Razonamiento Cuantitativo. Se evidencia adem\ue1s que el desarrollo del trabajo de laboratorio permiti\uf3 a los estudiantes desarrollar una conceptualizaci\uf3n m\ue1s acorde y cercano al campo conceptual establecido desde la qu\uedmica. Palabras claves: Estequiometr\ueda, Campos conceptuales, V Heur\uedstica Abstract Research results of an investigation of conceptual development are presented in a reference to the conceptual field stoichiometry of chemical reactions (CC-ERQ) practical work, carried out from the perspective of the theory of conceptual fields of Vergnaud (1990) with sophomores semester of Civil Engineering Lisandro Alvarado University (UCLA). The theoretical reference suggests that cognitive development depends on situations and problems conceptualizations. Situations allow the student explicite operative invariants (IO) are those that confer meaning to the concepts. The purpose was to evaluate the conceptual development of the student to explore links between cognitive structure and conceptual structure built from the chemical field, and then describe levels of conceptualization. a methodology that aims to promote the conceptual and procedural learning through the inclusion of epistemological V Gowin in laboratory work using problem solving as the core of the experimental work is proposed. The design of the proposal was based on field research, with interpretive approach. The sources of information were individual and group, written and oral productions, generated during the development of the laboratory in three (3) times fundamental research. The results confirm potential theory to address these links, manifested in the use of IO to face situations that demand a conceptualization, these shape representations of the chemical system. has an acceptable conceptual evolution framed in four types of representation of the CC-ERQ was given: Perceptive-Intuitively, formalist-Algorithmic, Rationalist-Theoretical and Quantitative Reasoning. It is further evidence that the development of laboratory work allowed students to develop a conceptualization more consistent and close to the conceptual field set from chemistry. Keywords: Stoichiometry, conceptual Campos, V Heuristics <br

Implementacion de un sistema teleoperado con realimentación visual para evasion de obstaculos de un robot movil

El presente proyecto consiste en la implementación de un sistema teleoperado con realimentación visual. Para esto se usa un sistema embebido (mini2440) colocado en un robot móvil con el propósito de controlarlo desde un computador distante, que se comunica con el sistema (mini 2440-robot-móvil) por medio del protocolo TCP. Junto al sistema embebido las envía al sistema remoto por medio del protocolo TCP en el mismo canal. Allí, el usuario recibirá la imagen enviada por el sistema y será capaz de controlar el movimiento del robot al enviar señales de control por medio del protocolo TCP. El sistema embebido, recibe dichas señales y se comunica con el robot por medio del puerto serial (RS 232)Pregrad

Localizing gravity on exotic thick 3-branes

We consider localization of gravity on thick branes with a non trivial structure. Double walls that generalize the thick Randall-Sundrum solution, and asymmetric walls that arise from a Z_2-symmetric scalar potential, are considered. We present a new asymmetric solution: a thick brane interpolating between two AdS_5 spacetimes with different cosmological constants, which can be derived from a ``fake supergravity'' superpotential, and show that it is possible to confine gravity on such branes.Comment: Final version, minor changes, references adde

Collaborative participatory research as a learning process: the case of CIP and CARE in Peru

Participatory research (PR) has been analyzed and documented from different points of view, but particularly taking into consideration the benefits that this process generates for farmers. Studies of the benefits of PR for other actors such as field staff, researchers and organizations have been limited, with organizational learning receiving the least attention. This paper analyzes the interaction between the International Potato Center (CIP) and CARE in Peru and makes the case that PR can also contribute to creating a collaborative learning environment that generates important lessons for the individuals and organizations involved. The paper describes the evolution of the collaborative environment of these two institutions for more than a decade. Three interactive learning periods are presented, namely the “information transfer period” (1993 –1996) the “action-learning period” (1997-2002), and the “social learning period” (on-going). Several lessons from each period, as well as changes in institutional contexts and perceptions, are described. The CIP-CARE case shows that research and developmentoriented organizations can interact fruitfully using PR as a mechanism to promote learning, as well as flexibility in interaction and innovativeness, and that a process of osmosis of information occurs between groups that use PR in a specific case to other groups within the organizations, influencing behavior. However, the paper also indicates that institutional learning should be promoted more specifically in order to extract guidelines from the lessons, which can influence the way organizations plan and implement their projects in a constantly changing environment

Descubriendo una nueva tecnología de innovación y comunicación para la enseñanza de la biología

170 p.La siguiente investigación aborda sobre la utilización de una estrategia metodológica basada en una TIC’s para la enseñanza de la Biología consistente en un juego llamado Kokori, cuya aplicación se llevó a cabo en un curso nuevo de primer año medio del colegio Rauquén de Curicó. El perfil de dicho curso se aleja de las exigencias del establecimiento, tanto por su deficiente rendimiento académico como también la motivación, siendo estos aspectos la base del objetivo principal de esta investigación la cual sugiere aplicar una estrategia científica - tecnológica de enseñanza aprendizaje a través de una TIC’s educativa con el fin de mejorar los niveles de aprendizaje del curso en cuestión. Se aplicó la estrategia en 4 sesiones a través del método de observación directa y participativa cuyos resultados evaluativos fueron analizados estadísticamente para medir los niveles de logro de los estudiantes y su posterior validación. Asimismo se logró concluir que la estrategia metodológica aplicada es bastante favorable al momento de su aplicación ya que arrojó resultados positivos en cuanto a rendimiento escolar y motivación de los estudiantes, considerándose una herramienta de enseñanza aprendizaje novedosamente tecnológica que se puede insertar en las aulas de los estudiantes del siglo XX

Spurious phosphorus pyramidalization induced by some DFT functionals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The molecular geometries of boraphosphabenzene (BP-benzene) and boron phosphorus coronene (BP-coronene) can be misinterpreted when they are obtained from density functional theory (DFT) calculations. In this study, we found that some exchange-correlation (XC) functionals yielded a distorted geometry of the above molecules when P atoms are present in their resonance structures. This phosphorus pyramidalization may be due to spurious errors caused by using these functionals. To verify this behavior, the electronic structures of BP-benzene and BP-coronene were studied using sixteen functionals (B3LYP, B97D, BHLYP, BP96, PBE, PBE0, PWLDA, Slater-Dirac-exchange, TPSS, M05, M06, M062X, M08HX, M11, wB97 and wB97X-D) with the SVP or TZVPP basis sets. The calculations were carried out using the TURBOMOLE and GAMESS programs. The geometry optimization calculations were carried out for each functional using both of the basis sets. Two different initial geometries, plane (D-3h symmetry) and distorted (C-1 symmetry) were considered. The optimized geometries of the BP-systems obtained at the MP2/TZVPP and CC2/TZVPP levels of theory exhibited D-3h symmetry. These calculations were used as a reference and compared with those obtained from DFT. The optimized geometries obtained from DFT were found to exhibit C-1 symmetry for the majority of the XC functionals.The molecular geometries of boraphosphabenzene (BP-benzene) and boron phosphorus coronene (BP-coronene) can be misinterpreted when they are obtained from density functional theory (DFT) calculations. In this study, we found that some exchange-correlation26816481655FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)sem informaçãosem informaçãoWe would like to acknowledge the computational facilities of the Chemistry Institute at UNICAMP as well as the financial support from Fundação de Amparo à Pesquisa de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (C

Tail Wags the Dog? Functional Gene Classes Driving Genome-Wide GC Content in Plasmodium spp

Plasmodium parasites are valuable models to understand how nucleotide composition affects mutation, diversification, and adaptation. No other observed eukaryotes have undergone such large changes in genomic Guanine-Cytosine (GC) content as seen in the genus Plasmodium (approximate to 30% within 35-40 Myr). Although mutational biases are known to influence GC content in the human-infective Plasmodium vivax and Plasmodium falciparum; no study has addressed how different gene functional classes contribute to genus-wide compositional changes, or if Plasmodium GC content variation is driven by natural selection. Here, we tested the hypothesis that certain gene processes and functions drive variation in global GC content between Plasmodium species. We performed a large-scale comparative genomic analysis using the genomes and predicted genes of 17 Plasmodium species encompassing a wide genomic GC content range. Genic GC content was sorted and divided into ten equally sized quantiles that were then assessed for functional enrichment classes. In agreement that selection on gene classes may drive genomic GC content, trans-membrane proteins were enriched within extreme GC content quantiles (Q1 and Q10). Specifically, variant surface antigens, which primarily interact with vertebrate immune systems, showed skewed GC content distributions compared with other trans-membrane proteins. Although a definitive causation linking GC content, expression, and positive selection within variant surface antigens from Plasmodium vivax, Plasmodium berghei, and Plasmodium falciparum could not be established, we found that regardless of genomic nucleotide composition, genic GC content and expression were positively correlated during trophozoite stages. Overall, these data suggest that, alongside mutational biases, functional protein classes drive Plasmodium GC content change.National Science Foundation [NSF IOS-1339156, IOS-1444490]; CyVerse [NSF IOS-1339156, IOS-1444490, NSF DBI-0735191, DBI-1265383]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]