Predicting the extinction of Ebola spreading in Liberia due to mitigation strategies

The Ebola virus is spreading throughout West Africa and is causing thousands of deaths. In order to quantify the effectiveness of different strategies for controlling the spread, we develop a mathematical model in which the propagation of the Ebola virus through Liberia is caused by travel between counties. For the initial months in which the Ebola virus spreads, we find that the arrival times of the disease into the counties predicted by our model are compatible with World Health Organization data, but we also find that reducing mobility is insufficient to contain the epidemic because it delays the arrival of Ebola virus in each county by only a few weeks. We study the effect of a strategy in which safe burials are increased and effective hospitalisation instituted under two scenarios: (i) one implemented in mid-July 2014 and (ii) one in mid-August---which was the actual time that strong interventions began in Liberia. We find that if scenario (i) had been pursued the lifetime of the epidemic would have been three months shorter and the total number of infected individuals 80\% less than in scenario (ii). Our projection under scenario (ii) is that the spreading will stop by mid-spring 2015

Predicting the extinction of Ebola spreading in Liberia due to mitigation strategies

The Ebola virus is spreading throughout West Africa and is causing thousands of deaths. In order to quantify the effectiveness of different strategies for controlling the spread, we develop a mathematical model in which the propagation of the Ebola virus through Liberia is caused by travel between counties. For the initial months in which the Ebola virus spreads, we find that the arrival times of the disease into the counties predicted by our model are compatible with World Health Organization data, but we also find that reducing mobility is insufficient to contain the epidemic because it delays the arrival of Ebola virus in each county by only a few weeks. We study the effect of a strategy in which safe burials are increased and effective hospitalisation instituted under two scenarios: (i) one implemented in mid-July 2014 and (ii) one in mid-August—which was the actual time that strong interventions began in Liberia. We find that if scenario (i) had been pursued the lifetime of the epidemic would have been three months shorter and the total number of infected individuals 80% less than in scenario (ii). Our projection under scenario (ii) is that the spreading will stop by mid-spring 2015.H.E.S. thanks the NSF (grants CMMI 1125290 and CHE-1213217) and the Keck Foundation for financial support. L.D.V. and L.A.B. wish to thank to UNMdP and FONCyT (Pict 0429/2013) for financial support. (CMMI 1125290 - NSF; CHE-1213217 - NSF; Keck Foundation; UNMdP; Pict 0429/2013 - FONCyT)Published versio

Low-Income Consumers in Brazil: Nuances of a Market That Can No Longer Be Ignored

The main goal of this paper is to better understand the low income Brazilian market, supported by two basic concepts: price unfairness and perceived product value. In order to meet the research objective a qualitative approach, based on two methodological procedures – observation and in-depth interviews –, was used. The findings indicate that small neighborhood retailers, despite lacking adequate physical infrastructure and management skills, play an important role in meeting the needs of low-income consumers. They offer convenience, personalized services, easy and uncomplicated credit (on an informal basis), and a product mix that matches the needs and desires of their customers. It was also found that although these small retailers charge higher prices than large supermarket chains, their customers still see value in their offerings and do not consider the prices asked to be unfair: they recognize that the benefits they receive outweigh the higher prices they pay. It was also found that low-income consumers relate with neighborhood retail stores in a basis that goes beyond the mere business, but in a cultural basis too. These small stores function not only as points of sale, but also as places where people can meet and discuss issues related to the local community. The principal contribution of this paper is in providing substantive information about the nuances of a market that has hitherto not been adequately explored but that holds a potential that can no longer be ignored. In Brazil, this market contains nearly 90 million consumers, eager to be included in the world of consumption. The findings presented by this study are of relevance not only to academic organisations and businesses, but also to social organizations and public policymakers responsible for improving the quality of life of the poor

A CASE STUDY IN TOPONYMY: SAMPLING AND CLASSIFYING A TRI-LINGUAL PLACE NAME INVENTORY FOUND IN THE NORTH-CENTRAL STATE OF NEW MEXICO

The north-central portion of the State of New Mexico has an extensive distribution of geographic names applied to landscape features from documented sources and from living oral tradition. Many of these geographic names originated from three distinct socio-linguistic groups, among which are names in three languages applied to single features. The three primary languages involved are Tewa, Spanish and English. Names that apply to topographical features and a selection of man-build features on the landscape were collected, mapped, and useful approaches to analyze them were developed from literature on toponymy, the study of place names. This study offers an analysis of the place names of the three socio-linguistic groups by classifying the names using a typology initially developed by the toponymist George R. Stewart but modified for use by this study. The typology assisted the comparison and contrast of naming practices of the namers and those who have used them over generations since. An area was selected for this study that employed names found in the database of the U.S. Board on Geographic Names associated with four U.S. Geological Survey 7.5 minute topographical maps named from east to west San Juan Pueblo, Chili, Vallecitos, and Polvadera Peak, New Mexico. To these quadrangles containing an area 28 miles long and 8.6 miles wide was added a considerable quantity of names discovered in literary sources ranging from John P. Harrington\u27s 1916 Ethnogeography of the Tewa to deed documents recorded in the Rio Arriba County Clerk\u27s Office. Another considerably large quantity of names was obtained from oral tradition and local common use accumulated over decades of time. The study area embraces San Juan Pueblo, a populated place of Pueblo Indians that speak the Tewa language, thence westward about eighteen miles to and including the summit of Cerro Chicoma in the west. San Juan Pueblo (Ohkay \xd3w\xeengeh) serves as a node and Cerro Chicoma as the west of four cardinal mountains defining a homeland of the Tewa speaking people of Ohkay \xd3w\xeengeh. Upon this study area a collection of Tewa names was mapped and used as the platform to initiated two more layers of Spanish and American English names. This study employed the visualization mapping tool Google Earth\u2122 to provided a computer generated terrain model upon which a collection of place names were mapped and color coded by language. Appendices F, G, and H of this study provide illustrations of this phase of the analysis by symbolically representing the place names as colored placemark points or linear features upon the of aerial imagery. An in-depth analysis was then developed for each name to provide its location, examine the name\u27s meaning, the name\u27s history (if known), and the name\u27s significance in the cultural landscape. An extensive catalogue of annotated place names found in the study area was developed and appears in Appendix D that provides the reader with these textual details of the inventory of geographic names. The typology developed for this study was applied to each place name that is presented as a spreadsheet list in Appendix C. This study limited the inventory of names to topographical features and a selection of man-built features on the cultural landscape using feature class definitions developed by the U.S. Board on Geographic Names (Table 9). The complete list is presented in Appendix B. A glossary devoted to generic names for geographic features in the three languages that appear in the study area and that appear as part of the place names herein presented are listed in Appendix A. These assist the reader to better understand definitions such as for a cerro or arroyo in this study. Because this study found government representation of officially designated names in the study area to be disproportionately in American English, Appendix E is provided listing the American English name inventory. The inventory of names, their annotations, and classifications were part of the method to compare and contrast the world views the name collection provides for each socio-linguistic group. Place names were found to be linguistic artifacts reflecting the physical, social, and spiritual norms of human-environment interaction of the past and present. The typology reveals that the Spanish socio-linguistic group underwent a process of nativization while naming features on the landscape during that history of human-environment interaction

Bt corn growing information system in Cagayan Province, Philippines: An analysis for enhanced extension delivery service

The adoption of Bacillus thuringiensis (Bt) corn gene has increased production and agricultural information exchange plays a vital role towards sustained production growth. The study examined the information system by assessing the usefulness of information, frequency of consultations and strength of information exchange in Bt corn production in Cagayan Province, Philippines. Using descriptive correlation design, it was revealed that both technical and economic information from all sources were rated useful. Technical information on seed variety, land preparation, weather forecast, soil management and fertilizer application are frequently utilized while on the economic information only current market prices was frequently used. Frequency of Consultation with personal information sources gained the highest mean value of 5.02 signifying a two to three times exchange of information. Public information sources obtained an average mean of 2.80 which means four or five times contact in a year. This reveals the gap between the corn growers and public information sources. For the mass media sources, both radio (4.56) and television (4.72) are frequently used at two to three times a month. Personal information sources showed strong (224.25 IS) exchange of information between and among the Bt corn growers which comprise their communication network. Total information scores from public and mass media information sources revealed weak exchange of information. The total information score is significantly correlated with membership to organization, years of membership, nature of membership, land ownership and position in the farm. Total information score from friends, radio and newspaper showed significant relationship with income. Thus, information exchange with friends, listening to radio and reading newspaper had a significant influence on the increase of corn growers’ income

Finite-Size-Scaling at the Jamming Transition: Corrections to Scaling and the Correlation Length Critical Exponent

We carry out a finite size scaling analysis of the jamming transition in frictionless bi-disperse soft core disks in two dimensions. We consider two different jamming protocols: (i) quench from random initial positions, and (ii) quasistatic shearing. By considering the fraction of jammed states as a function of packing fraction for systems with different numbers of particles, we determine the spatial correlation length critical exponent $\nu\approx 1$, and show that corrections to scaling are crucial for analyzing the data. We show that earlier numerical results yielding $\nu<1$ are due to the improper neglect of these corrections.Comment: 5 pages, 4 figures -- slightly revised version as accepted for Phys. Rev. E Rapid Communication

ESTUDIO DEL COMPORTAMIENTO ESTRUCTURAL DE LOSAS MACIZAS DE CONCRETO REFORZADO PARA VIVIENDA

A partir de resultados analíticos de ejemplos ilustrativos y del reporte de características observadas, quedó demostradoque las losas macizas de concreto reforzado para vivienda no son diseñadas ni construidas adecuadamente en el ámbitode la zona de estudio, lo que explica los altos porcentajes de fallas observadas en servicio. Fue calculado el índice deconfiabilidad en seis viviendas representativas al considerar tres posibles escenarios de la corrosión del acero de refuerzo,con lo que se mostró un alto riesgo de falla o cuantiosas inversiones en mantenimiento. Se concluyó que para el correctodiseño de las losas deberá no sólo revisarse la resistencia a flexión sino principalmente controlar las deformacionesverticales, el agrietamiento por contracción y la permeabilidad, lo cual implica especificar un concreto denso y durable.Se presentan recomendaciones específicas