The relationship between the reading capacities and the reading achievements of pupils in grades two through grades six

Thesis (M.A.)--Boston University, 195

Influential Article Review – Applying Statistics in Stock Market Decision

This paper examines the stock market. We present insights from a highly influential paper. Here are the highlights from this paper: Forecasting stock returns is extremely challenging in general, and this task becomes even more difficult given the turbulent nature of the Chinese stock market. We address the stock selection process as a statistical learning problem and build cross-sectional forecast models to select individual stocks in the Shanghai Composite Index. Decile portfolios are formed according to rankings of the forecasted future cumulative returns. The equity market’s neutral portfolio—formed by buying the top decile portfolio and selling short the bottom decile portfolio—exhibits superior performance to, and a low correlation with, the Shanghai Composite Index. To make our strategy more useful to practitioners, we evaluate the proposed stock selection strategy’s performance by allowing only long positions, and by investing only in A-share stocks to incorporate the restrictions in the Chinese stock market. The long-only strategies still generate robust and superior performance compared to the Shanghai Composite Index. A close examination of the coefficients of the features provides more insights into the changes in market dynamics from period to period. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

An Empirical Investigation of the Relationshops Among Math Confidence, Computer Confidence and Computer Self-Efficacy: Implications for Technology Education

A popular issue in the 1980’s and early 1990’s, computer self-efficacy (CSE) remains an important area of research. Educators, industry leaders, and government officials argue that the United States is falling behind other countries in technology innovation. And, most attribute this situation to ineffective education in the areas of math, science, and technology. The current study provides insight into these issues by linking math confidence, computer confidence, and CSE. Four hypotheses were tested using data gathered from undergraduate business students in a southern university. The results were significant, suggesting that both Math Confidence and Computer Confidence have a significant effect on CSE, both directly and indirectly. This study extends prior research on CSE by examining the link between Math Confidence and CSE and posits that technology educators may be well-served to consider some of the same techniques and methodologies applied in mathematics education to improve CSE in college students

Not just a migration problem: Metapopulations, habitat shifts and gene flow are also important for fishway science and management

Worldwide, fishways are increasingly criticized for failing to meet conservation goals. We argue that this is largely due to the dominance of diadromous species of the Northern Hemisphere (e.g., Salmonidae) in the research that underpins the concepts and methods of fishway science and management. With highly diverse life histories, swimming abilities and spatial ecologies, most freshwater fish species do not conform to the stereotype imposed by this framework. This is leading to a global proliferation of fishways that are often unsuitable for native species. The vast majority of fish populations do not undertake extensive migrations between clearly separated critical habitats, yet the movement of individuals and the genetic information they carry is critically important for population viability. We briefly review some of the latest advances in spatial ecological modelling for dendritic networks to better define what it means to achieve effective fish passage at a barrier. Through a combination of critical habitat assessment and the modelling of metapopulations, climate change�driven habitat shifts, and adaptive gene flow, we recommend a conceptual and methodological framework for fishway target�setting and monitoring suitable for a wide range of species. In the process, we raise a number of issues that should contribute to the ongoing debate about fish passage research and the design and monitoring of fishways

Laboratory and Experimental Hut Evaluation of a Long-lasting Insecticide Treated blanket for Protection against Mosquitoes.

Long-lasting insecticide treated blankets (LLIBs) may provide additional protection against malaria where use of long lasting insecticidal nets (LLIN) is low or impractical such as in disaster or emergency situations. Initial efficacy testing of a new candidate LLIB was carried out at LSHTM and KCMUCo, before and after washing, in cone and ball bioassays and arm-in-cage tests against pyrethroid susceptible Anopheles gambiae. A small scale field trial was conducted using veranda-trap experimental huts in northern Tanzania against wild An. arabiensis and Culex quinquefasciatus mosquitoes. Treatments included unwashed and 5 times washed permethrin treated LLIB and blankets hand-treated with permethrin (ITB), untreated blankets, and a holed unwashed Olyset net. Cone test mortality was 75% for LLIB when unwashed, but decreased to 32% after 5 washes and <10% after 10 washes. In arm-in-cage tests protection against biting was 100% for LLIBs regardless of the number of washes while reduction in landings was 79% when unwashed, 75% after 5 washes, but declined to 41% after 10 and 33% after 20 washes. In ball bioassays using pyrethroid resistant An. arabiensis, mortality was low in all treatments (<35%) and there was no significant difference in mortality between Olyset net, LLIB or ITB (p > 0.05). Percentage mortality of An. arabiensis in huts with LLIB unwashed (26%) was not statistically different to Olyset net (31%, p = 0.5). The 5 times washed LLIB reduced blood-feeding by 49% which was equivalent to Olyset net (p > 0.086). There was no significant difference in percentage blood-feeding between LLIB and ITB unwashed or 5 times washed (p = 0.147 and p = 0.346 respectively). The 5 times washed LLIB reduced blood-feeding of Culex quinquefasciatus by 40%, although the Olyset provided the greatest protection with 85% inhibition. ELISA analysis of a sub-sample of blood fed mosquitoes showed that not all had fed on humans in the huts, therefore blood-feeding inhibition may have been underestimated. This trial demonstrated the potential of LLIBs to provide substantial personal protection even against pyrethroid resistant mosquitoes. LLIBs may prove particularly useful where LLINs are unsuitable or net usage is low

A Multi-Scale Test of the Forage Maturation Hypothesis in a Partially Migratory Ungulate Population

The forage maturation hypothesis (FMH) proposes that ungulate migration is driven by selection for high forage quality. Because quality declines with plant maturation, but intake declines at low biomass, ungulates are predicted to select for intermediate forage biomass to maximize energy intake by following phenological gradients during the growing season. We tested the FMH in the Canadian Rocky Mountains by comparing forage availability and selection by both migrant and nonmigratory resident elk (Cervus elaphus) during three growing seasons from 2002-2004. First, we confirmed that the expected trade-off between forage quality and quantity occurred across vegetation communities. Next, we modeled forage biomass and phenology during the growing season by combining ground and remote-sensing approaches. The growing season started 2.2 days earlier every 1 km east of the continental divide, was delayed by 50 days for every 1000-m increase in elevation, and occurred 8 days earlier on south aspects. Migrant and resident selection for forage biomass was then compared across three spatial scales (across the study area, within summer home ranges, and along movement paths) using VHF and GPS telemetry locations from 119 female elk. Migrant home ranges occurred closer to the continental divide in areas of higher topographical diversity, resulting in migrants consistently selecting for intermediate biomass at the two largest scales, but not at the. nest scale along movement paths. In contrast, residents selected maximum forage biomass across all spatial scales. To evaluate the consequences of selection, we compared exposure at telemetry locations of migrant and resident elk to expected forage biomass and digestibility. The expected digestibility for migrant elk in summer was 6.5% higher than for residents, which was corroborated with higher fecal nitrogen levels for migrants. The observed differences in digestibility should increase migrant elk body mass, pregnancy rates, and adult and calf survival rates. Whether bottom-up effects of improved forage quality are realized will ultimately depend on trade-offs between forage and predation. Nevertheless, this study provides comprehensive evidence that montane ungulate migration leads to greater access to higher-quality forage relative to nonmigratory congeners, as predicted by the forage maturation hypothesis, resulting primarily from large-scale selection patterns

Perspectivas individuales de los directivos: influencia de redes e influencia de conocimiento del administrador/directivo en el proceso de internacionalización de las Pymes ecuatorianas.

En este estudio analizaremos la influencia de las redes e influencia del conocimiento para lograr el grado de internacionalización de las pymes en Ecuador, ocupando dos brechas investigativas; por un lado, para redes y por otro en conocimiento., Hemos desarrollado metodología hibrida (entrevistas, y explotación de datos). Destacamos nuestras conclusiones más relevantes., Las Pymes en Ecuador poseen un enorme potencial para generar producción, empleo e ingresos. No obstante, las empresas ecuatorianas, por falta de las perspectivas de los directivos, en sus efectos de influencia en redes y conocimiento, no han podido expandir totalmente sus productos para el mercado internacional

Factores de riesgo cardiovascular: desde los clásicos hasta los emergentes a la luz de las nuevas evidencias

Cardiovascular diseases (CVD) are the main cause of morbidity and mortality worldwide, especially affecting the population over 60 years of age, they can manifest depending on their origin in coronary disease (acute myocardial infarction, angina pectoris, sudden cardiac arrest, heart failure and sudden death) and cerebrovascular disease (strokes and transient ischemic events). Several risk factors associated with the development of CVD have been described, the classic factors (modifiable and non-modifiable), and others that have been added to the list as a result of new evidence, such as inflammation, thrombosis, stress, alterations in the levels of natriuretic peptides, heavy metals/environmental pollutants, renal insufficiency, and some infectious agents. The objective of this article is to present the state of the art associated with classic cardiovascular risk factors (CRFs) and the evidence that supports emerging CRFs.&nbsp;&nbsp;Las enfermedades cardiovasculares (ECV) son la causa principal de morbimortalidad a nivel mundial, afectando especialmente a la población mayor de 60 años, pueden manifestarse según su origen en enfermedad coronaria (infarto agudo de miocardio, angina pectoris, insuficiencia cardiaca, y muerte súbita) y enfermedad cerebrovascular (accidentes cerebrovasculares y eventos isquémicos transitorios). Varios factores de riesgo asociados al desarrollo de las ECV han sido descritos; los factores clásicos (modificables y no modificables), y otros que se han añadido a la lista como producto de las nuevas evidencias como es el caso de la inflamación, trombosis, estrés, alteraciones en los niveles de péptidos natriuréticos, metales pesados/contaminantes ambientales, insuficiencia renal y algunos agentes infecciosos. El objetivo de este artículo es presentar el estado del arte asociado con los factores de riesgo cardiovasculares (FRC) clásicos y las evidencias que soportan los FRC emergentes.&nbsp;&nbsp

COVID-19 Transmission in Children: Implications for Schools

The COVID-19 pandemic poses multiple issues of importance to child health including threats to physical health and disruption of in-school learning. This chapter reviews what is currently known about COVID-19 epidemiology, presentation, pathophysiology, case definitions, therapies, and in-school transmission in children. COVID-19 has some unique characteristics in children including the rare yet severe Multisystem Inflammatory Syndrome in Children (MIS-C) that may be related to acquired immune responses. There are limited studies to date to define therapeutic guidelines in children, however consensus recommendations from multiple organizations are summarized including the use of immunomodulatory therapies (intravenous immunoglobulin, steroids, anakinra and tocilizumab), antiplatelet (aspirin) and anti-coagulant (low molecular weight heparin) therapies. Finally, considerations for safe return to the classroom are discussed including strategies for optimized student to teacher ratios, hand washing, social distancing, sibling pairing and staged re-opening strategies