Microsegmentación de la demanda urbana: técnicas innovadoras en la provisión de servicios públicos urbanos

Peer Reviewe

The effects of a short-term corporate social impact activity on employee turnover: field experimental evidence

Short-term corporate social impact activities, wherein employees participate in firm-sponsored prosocial initiatives, are becoming increasingly common. However, it remains unclear whether short-term social impact activities affect employee behavior in a manner of relevance to the firm. Theoretically, arguments could be made in favor of or against the likelihood that such short-term activities would increase firm-benefitting employee behavior. We utilized data from a randomized field experiment implemented at a large Latin American bank to examine whether a short-term social impact activity can be beneficial for firms, focusing on one important outcome: turnover. Newly hired employees were randomly assigned to a short-term social impact activity as part of the new employee onboarding process or not. Notably, we find causal evidence that a day-long, short-term engagement reduced employee turnover almost a year later. We explore potential mechanisms behind this effect and find that employees’ perceptions of organizational justice help to explain the effects of the intervention on turnover. We also explore heterogeneous treatment effects and find more substantial effects for male, rather than female, employees. This paper advances the literature on the implications of corporate social responsibility (CSR) practices by shedding light on the causal mechanisms through which a theoretically underexplored and practically relevant type of CSR activity can benefit organizations and their employees

Mining ancient microbiomes using selective enrichment of damaged DNA molecules

The identification of bona fide microbial taxa in microbiomes derived from ancient and historical samples is complicated by the unavoidable mixture between DNA from ante- and post-mortem microbial colonizers. One possibility to distinguish between these sources of microbial DNA is querying for the presence of age-associated degradation patterns typical of ancient DNA (aDNA). The presence of uracils, resulting from cytosine deamination, has been detected ubiquitously in aDNA retrieved from diverse sources, and used as an authentication criterion. Here, we employ a library preparation method that separates molecules that carry uracils from those that do not for a set of samples that includes Neandertal remains, herbarium specimens and archaeological plant remains

Memorias y tradición oral afroecuatoriana de Nueva Loja

La provincia de Sucumbíos, creada en 1989, nació con la presencia de nacionalidades indígenas, población mestiza y pueblo afroecuatoriano; su vertiginoso aumento poblacional y desarrollo económico tienen que ver con la actividad petrolera, agrícola y comercial de la zona

Influence of germination on lectin in Lens culinaris seeds

The effect of germination conditions on the lectin of Lens culinaris var. Magda 20 seeds was studied. The seeds were germinated at 20 °C under different conditions of watering and light and for different periods of time. The seed lectin was assayed by haemagglutination and quantified by competitive ELISA. Changes in lectin content during germination were also monitored by SDS-PAGE and immunoblotting. Haemagglutinating activity and lectin content in the seeds were not changed during the first three days regardless of the conditions of the germination. However, lectin concentration was significantly higher after six days of germination; relative lectin levels being particularly high when germination was carried out in the light and with daily watering. The results of SDS-PAGE and immunoblotting have also shown that the lectin was not degraded during the first six days of germination however, other storage-proteins were broken down by proteolysis

Counting the photons : determining the absolute storage capacity of persistent phosphors

The performance of a persistent phosphor is often determined by comparing luminance decay curves, expressed in cd/m(2). However, these photometric units do not enable a straightforward, objective comparison between different phosphors in terms of the total number of emitted photons, as these units are dependent on the emission spectrum of the phosphor. This may lead to incorrect conclusions regarding the storage capacity of the phosphor. An alternative and convenient technique of characterizing the performance of a phosphor was developed on the basis of the absolute storage capacity of phosphors. In this technique, the phosphor is incorporated in a transparent polymer and the measured afterglow is converted into an absolute number of emitted photons, effectively quantifying the amount of energy that can be stored in the material. This method was applied to the benchmark phosphor SrAl2O4: Eu, Dy and to the nano-sized phosphor CaS: Eu. The results indicated that only a fraction of the Eu ions (around 1.6% in the case of SrAl2O4: Eu, Dy) participated in the energy storage process, which is in line with earlier reports based on X-ray absorption spectroscopy. These findings imply that there is still a significant margin for improving the storage capacity of persistent phosphors

Differential loss of effector genes in three recently expanded pandemic clonal lineages of the rice blast fungus

BACKGROUND: Understanding the mechanisms and timescales of plant pathogen outbreaks requires a detailed genome-scale analysis of their population history. The fungus Magnaporthe (Syn. Pyricularia) oryzae-the causal agent of blast disease of cereals- is among the most destructive plant pathogens to world agriculture and a major threat to the production of rice, wheat, and other cereals. Although M. oryzae is a multihost pathogen that infects more than 50 species of cereals and grasses, all rice-infecting isolates belong to a single genetically defined lineage. Here, we combined the two largest genomic datasets to reconstruct the genetic history of the rice-infecting lineage of M. oryzae based on 131 isolates from 21 countries. RESULTS: The global population of the rice blast fungus consists mainly of three well-defined genetic groups and a diverse set of individuals. Multiple population genetic tests revealed that the rice-infecting lineage of the blast fungus probably originated from a recombining diverse group in Southeast Asia followed by three independent clonal expansions that took place over the last ~ 200 years. Patterns of allele sharing identified a subpopulation from the recombining diverse group that introgressed with one of the clonal lineages before its global expansion. Remarkably, the four genetic lineages of the rice blast fungus vary in the number and patterns of presence and absence of candidate effector genes. These genes encode secreted proteins that modulate plant defense and allow pathogen colonization. In particular, clonal lineages carry a reduced repertoire of effector genes compared with the diverse group, and specific combinations of presence and absence of effector genes define each of the pandemic clonal lineages. CONCLUSIONS: Our analyses reconstruct the genetic history of the rice-infecting lineage of M. oryzae revealing three clonal lineages associated with rice blast pandemics. Each of these lineages displays a specific pattern of presence and absence of effector genes that may have shaped their adaptation to the rice host and their evolutionary history

Valoración Del Desempeño Del Proceso De Reparaciones En Un Sistema De Distribución De Electricidad

Este artículo presenta una metodología para valorar el desempeño del proceso de reparaciones en un sistema de distribución local de electricidad (SDL), la cual modela los recursos para reparación y su logística como un sistema de colas cuya entrada y cuyo servicio son procesos estocásticos puntuales estacionarios o no estacionarios. El cálculo de los índices de desempeño del proceso se realiza mediante un procedimiento de simulación de Montecarlo secuencial. Luego de analizar un SDL típico colombiano, se encontró que el tiempo de espera es el índice que mejor refleja el desempeño del proceso de reparaciones