Impact of Cosmic Variance on the Galaxy-Halo Connection for Lyman-α\alpha Emitters

In this paper we study the impact of cosmic variance and observational uncertainties in constraining the mass and occupation fraction, $f_{\rm occ}$, of dark matter halos hosting Ly-$\alpha$ Emitting Galaxies (LAEs) at high redshift. To this end, we construct mock catalogs from an N-body simulation to match the typical size of observed fields at $z=3.1$ ($\sim 1 {\rm deg^2}$). In our model a dark matter halo with mass in the range $M_{\rm min}<M_{\mathrm h}<M_{\rm max}$ can only host one detectable LAE at most. We proceed to explore the parameter space determined by $M_{\rm min}$,$M_{\rm max}$ and $f_{\rm occ}$ with a Markov Chain Monte-Carlo algorithm using the angular correlation function (ACF) and the LAEs number density as observational constraints. We find that the preferred minimum and maximum masses in our model span a wide range $10^{10.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm min} \leq 10^{11.1}h^{-1}{\rm{M_{\odot}}}$ , $10^{11.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm max} \leq 10^{13.0}h^{-1}{\rm{M_{\odot}}}$; followed by a wide range in the occupation fraction $0.02\leq f_{\rm occ} \leq 0.30$. As a consequence the median mass, $M_{50}$, of all the consistent models has a large uncertainty $M_{50} = 3.16^{+9.34}_{-2.37}\times 10^{10}$$h^{-1}{\rm{M_{\odot}}}$. However, we find that the same individual models have a relatively tight $1\sigma$ scatter around the median mass $\Delta M_{1\sigma} = 0.55^{+0.11}_{-0.31}$ dex. We are also able to show that \focc\ is uniquely determined by $M_{\rm min}$, regardless of $M_{\rm max}$. We argue that upcoming large surveys covering at least $25$ deg$^{2}$ should be able to put tighter constraints on $M_{\rm min}$ and $f_{\rm occ}$ through the LAE number density distribution width constructed over several fields of $\sim 1$ deg$^{2}$.Comment: 7 Pages, 5 figures. Accepted for publication in Ap

The Effect of Ethanol Production on Coarse Grains: New Price Relationships

For years, the U.S. price of grain sorghum has been settled as 95% of the price of corn. Nevertheless, the increasing demand for corn and grain sorghum in ethanol production might have changed that price relationship. In this study, we use cointegration and the vector autoregressive model with independent variable (VARX) to assess the relationship between the spot price of sorghum in several U.S. markets and corn’s futures market price during the period 1996–2008. The results indicate a price relationship between the price of sorghum in the Gulf ports, Kansas City, and Texas, and corn prices of 1.01, 0.99, and 0.99, respectively. These new relationships are noteworthy for producers and other stakeholders.causality test, cointegration, futures markets, VARX model, Agribusiness, Marketing,

Technical solutions to prevent heat stress induced crop growth reduction for three climatic regions in Mexico

In the last 15 years a significant increase in greenhouse area has occurred in Mexico, from a modest 50 hectares in 1990 to over 2,000 hectares in 2004. The rapid increase in greenhouse area is a result of an attractive export market, USA. Mexican summer midday temperatures are well above crop optimum and cooling is needed if heat stress induced crop growth reduction is to be prevented. The objective of this study was to determine the effectiveness and feasibility of greenhouse cooling systems for tomato culture under desert, humid tropic and temperate Mexican weather conditions. These climate regions are represented by Mexicali, Merida and Huejutla respectively. The cooling systems included a variety of passive and active systems, which through an engineering design methodology were combined to suit the climate conditions of the 3 regions. The evaluation was conducted via simulation, taking into account the most important temperature effects on crop growth and yield. The results showed that the cooling systems were effective in decreasing heat stress to plants. Investment costs of greenhouse with cooling equipment were under USD 50 m-2 and operational costs were under USD 10 m-2 for all equipment combinations and treatments except for the humid tropic climate of Merida. Solutions for Merida were both economically and physically not feasible due to too high humidity levels. This model study clearly indicates that cooling is feasible in desert and moderate climate regions of Mexico but in humid tropic climate regions feasibility is a problem. Application of design methodology and design evaluation with help of simulation greatly contributed to pointing out effective and non-effective solutions to reduce heat stress in hot climates

Detection of enteric parasite DNA in household and bed dust samples: potential for infection transmission.

BACKGROUND: Enteric parasites are transmitted in households but few studies have sampled inside households for parasites and none have used sensitive molecular methods. METHODS: We collected bed and living room dust samples from households of children participating in a clinical trial of anthelmintic treatment in rural coastal Ecuador. Dust was examined for presence of DNA specific for 11 enteric parasites (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Toxocara canis and T. cati, Giardia lamblia, Blastocystis hominis, Cryptosporidium spp., and Entamoeba histolytica) by quantitative PCR (qPCR). RESULTS: Of the 38 households sampled, 37 had positive dust for at least one parasite and up to 8 parasites were detected in single samples. Positivity was greatest for B. hominis (79% of household samples) indicating a high level of environmental fecal contamination. Dust positivity rates for individual pathogens were: S. stercoralis (52%), A. lumbricoides (39%), G. lamblia (39%), Toxocara spp. (42%), hookworm (18%) and T. trichiura (8%). DNA for Cryptosporidium spp. and E. histolytica was not detected. Bed dust was more frequently positive than floor samples for all parasites detected. Positivity for A. lumbricoides DNA in bed (adjusted OR: 10.0, 95% CI: 2.0-50.1) but not floor dust (adjusted OR: 3.6, 95% CI: 0.3-37.9) was significantly associated with active infections in children. CONCLUSIONS: To our knowledge, this is the first use of qPCR on environmental samples to detect a wide range of enteric pathogen DNA. Our results indicate widespread contamination of households with parasite DNA and raise the possibility that beds, under conditions of overcrowding in a humid tropical setting, may be a source of transmission

Factores de riesgos clinicas y epidemiologicos que influyen en el desarrollo de hipertension arterial en pacientes diabeticos, atendidos en el centro de salud Lacayo Farfan, durante el año 2015

En el mundo hay más de 347 millones de personas con diabetes. Se calcula que en 2004 fallecieron 3,4 millones de personas como consecuencias del exceso de azúcar en la sangre. En Nicaragua este es un problema de salud pública que cada día va en aumento. El presente trabajo está dirigido al estudio y análisis de los principales factores de riesgo clínico y epidemiológico que influyen en el desarrollo de la hipertensión arterial en pacientes diabéticos del Centro de Salud Lacayo Farfán del municipio de Matagalpa durante el año 2013 enfocando también la dificultad para el manejo y control de las descompensaciones. Es un estudio de casos y controles y cuyo método de recolección de información fueron entrevistas dirigidas al paciente y fichas llenadas con el expediente clínico. Durante el desarrollo del trabajo encontramos como principal factor de riesgo para desarrollar hipertensión arterial de los pacientes diabéticos, es la presencia de antecedentes genéticos asociado a los hábitos de vida poco saludables y que estos conlleva a la aparición de sobrepeso u obesidad en estos pacientes. Como dato relevante encontramos que estos pacientes son manejados principalmente con beta bloqueadores (Atenolol) a pesar que las guías internacionales proponen otro manejo. Por lo tanto concluimos que para mejorar la atención adecuada de los pacientes, se debe realizar controles periódicos, impartir charlas periódicas sobre el cuido personal, la medicación adecuada y procurar una vida sana a base de una alimentación sana y actividad física cotidian

Promoting Social Justice through Service-Learning in Urban Teacher Education: The Role of Student Voice

Although service-learning is becoming more common in teacher education programs (Anderson & Erickson 2003), few detailed case descriptions show how service-learning can help to promote a social justice orientation for prospective teachers. A comparative descriptive analysis of projects within two teacher preparation programs--one focused on training undergraduates and one focused on training graduate students--illustrates how service-learning, when undergirded by student voice work, prepares prospective educators to teach for social justice in urban classrooms. We identify commonalities in our two approaches to integrating service-learning and student voice into the teacher education curriculum, and we show how our distinctive efforts support prospective teachers in developing the relationships, reflections, and practices they need to become effective educators of urban youth

Evolutionary, structural and functional insights in nuclear organisation and nucleocytoplasmic transport in trypanosomes

One of the remarkable features of eukaryotes is the nucleus, delimited by the nuclear envelope (NE), a complex structure and home to the nuclear lamina and nuclear pore complex (NPC). For decades, these structures were believed to be mainly architectural elements and, in the case of the NPC, simply facilitating nucleocytoplasmic trafficking. More recently, the critical roles of the lamina, NPC and other NE constituents in genome organisation, maintaining chromosomal domains and regulating gene expression have been recognised. Importantly, mutations in genes encoding lamina and NPC components lead to pathogenesis in humans, while pathogenic protozoa disrupt the progression of normal development and expression of pathogenesis-related genes. Here, we review features of the lamina and NPC across eukaryotes and discuss how these elements are structured in trypanosomes, protozoa of high medical and veterinary importance, highlighting lineage-specific and conserved aspects of nuclear organisation.</p