Environmental context of endophyte symbioses: Interacting effects of water stress and insect herbivory

Symbiotic associations between grasses and fungal endophytes are generally regarded as mutualistic, yet benefits to host plants may vary with environmental context. Previous studies have emphasized how endophytes influence plant responses to single stressors. In contrast, the outcome of endophyte-grass interactions under simultaneous biotic and abiotic stresses remains poorly explored. We hypothesized that benefits from endophyte symbiosis become most apparent in "complex" environments where hosts experience multiple stresses. We evaluated the performance of endophyte-infected (E+) vs. endophyte-uninfected (E-) Lolium multiflorum plants in a factorial experiment with water supply (control vs. drought) and insect herbivory (with aphids vs. without aphids). Endophyte infection delayed tiller production in well-watered plants, while water stress reduced tillering in E- plants. Endophyte mediation of herbivory tolerance was contingent on water supply. Whereas aphid herbivory was detrimental to E+ plants in well-watered soils, aphids interacted with drought stress in decreasing the reproductive output of E- but not E+ plants. Moreover, endophyte presence decreased aphid densities on drought-stressed plants only. Thus, endophyte symbiosis enhanced host tolerance to overlapping biotic and abiotic stresses, although infected plants failed to outgrow their uninfected counterparts. These results support the view that mutualistic endophyte effects may not arise in low-stress environments. © 2011 by The University of Chicago. All rights reserved.Fil: Miranda, M. Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Omacini, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Chaneton, Enrique Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

An Experiment Of The Effect Of Teaching Different Computational Methods Of Operating Cash Flows On Student Understanding

This study uses an experimental approach to determine if student understanding of the association between depreciation and cash flows differs based on which method of computing operating cash flows is presented to students.   The participants are undergraduate and graduate students in business at a major university in the southwest United States.  The participants attended sessions where they heard a brief lecture explaining operating cash flows using either the direct or indirect methods.&nbsp

An Experiment Of Student Understanding Of Accruals Versus Cash Flows

The concepts of both accrual accounting and cash basis accounting need to be thoroughly understood by accounting graduates as they enter the workplace.  In making decisions, both managers and investors often may need to make adjustments from one basis to the other.  But do students really understand these concepts?  This study uses an experimental approach to determine if students in both the U.S. and Mexico understand the association between accrual and cash flow numbers in the area of depreciation.  The results reveal that the majority of student participants in both countries do not understand the relationship between depreciation and cash flows.  This suggests that the way depreciation is taught in intermediate accounting may need to be approached differently in order for students to understand the nature of depreciation and its effect on earnings and cash flows

A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139

We report on a water maser survey towards a sample of 27 planetary nebulae (PNe) using the Robledo de Chavela and Medicina single-dish antennas, as well as the Very Large Array (VLA). Two detections have been obtained: the already known water maser emission in K 3-35, and a new cluster of masers in IRAS 17347-3139. This low rate of detections is compatible with the short life-time of water molecules in PNe (~100 yr). The water maser cluster at IRAS 17347-3139 are distributed on a ellipse of size ~ 0.2" x 0.1", spatially associated with compact 1.3 cm continuum emission (simultaneously observed with the VLA). From archive VLA continuum data at 4.9, 8.4, and 14.9 GHz, a spectral index alpha = 0.76 +- 0.03 is derived for this radio source, which is consistent with either a partially optically thick ionized region or with an ionized wind. However, the latter scenario can be ruled out on mass-loss considerations, thus indicating that this source is probably a young PN. The spatial distribution and the radial velocities of the water masers are suggestive of a rotating and expanding maser ring, tracing the innermost regions of a torus formed at the end of the AGB phase. Given that the 1.3 cm continuum emission peak is located near one of the tips of the major axis of the ellipse of masers, we speculate on a possible binary nature of IRAS 17347-3139, where the radio continuum emission could belong to one of the components and the water masers would be associated with a companion.Comment: Accepted by The Astrophysical Journal. 25 pages, 6 figure

Corporate social responsibility practices in the hotel sector. Case studies in Santa Marta city, Colombia

[ES] El presente trabajo tiene como fin identificar, diagnosticar y evaluar las prácticas de Responsabilidad Social Empresarial (RSE) de ocho hoteles de diferentes tamaños ubicados en la ciudad de Santa Marta, Colombia. A partir de la teoría del desarrollo sostenible fundamentada en la ética, fue aplicado el método del estudio de caso, para concluir que las empresas hoteleras se ubican dentro de un rango de aplicación mínimo, bajo y medio. De igual manera, se encuentran clasificadas en los grupos de reactivas-filantrópicas, reactivas-legales y activas, dando una mayor importancia y valoración al desarrollo de actividades económicas relacionadas con clientes, producto, trabajadores y proveedores locales. En relación a las implicaciones, el estudio brinda información útil en materia de RSE, para mejorar la toma decisiones, tanto de los propietarios de los hoteles, como de sus stakeholders más influyentes. En concreto, para el empresario, en gestión y operación; para el dirigente político, en política pública del sector; para el cliente, en decisiones de compra; para la academia, en decisiones sobre investigaciones en marcha o nuevas investigaciones; y para la comunidad local, en control y seguimiento que permita legitimar o no la actividad empresarial. Futuras investigaciones deberían incluir más stakeholders y empresas de otros sectores económicos de la zona del estudio.[EN] This paper aims to identify, diagnose and evaluate the practices of Corporate Social Responsibility (CSR) of eight hotels of different sizes located in Santa Marta, Colombia. From the theory of sustainable development based on ethic, the case study method was applied. It was found that hotel companies are located within a range of minimum, low and medium application, classified in philanthropic-reactive, legal-reactive and active groups, giving greater importance and value to the development of economic activities related to customers, product, workers and local suppliers. The study provides useful information on CSR, to improve decision making, both hotel owners, and their most influential stakeholders. Specifically, for employers, management and operation; for political leaders, public policy in the sector; for customers, in purchasing decisions; for academy, in decisions about ongoing investigations or further research; for local community, enabling control and monitoring legitimize or business. Future research should include more stakeholders and companies from other economic sectors in the study area.Este artículo es resultado de la Pasantía de Investigación en el marco del Programa de Doctorado Interuniversitario en Turismo de la Universidad de Málaga del primer autor en el Grupo de Investigación en Sistemas Costeros (COL 087006) de la compañía Playas Corporación Ltd. (Santa Marta, Colombia)

Differentiation Between Women With Vulvovaginal Symptoms Who are Positive or Negative for Candida Species by Culture

Objective: To investigate whether clinical criteria could differentiate between women with vulvovaginitis who were culture positive or negative for vaginal Candida species. Methods: Vulvovaginal specimens were obtained from 501 women with a vaginal discharge and/or pruritis. Clinical information and wet mount microscopy findings were obtained. All specimens were sent to a central laboratory for species identification. Results: A positive culture for Candida species was obtained from 364 (72.7%) of the specimens. C. albicans was identified in 86.4% of the positive cultures, followed by C. glabrata in 4.5%, C. parapsilosis in 3.9%, C. tropicalis in 2.7% and other Candida species in 1.4%.Women with a positive Candida culture had an increased utilization of oral contraceptives (26.1% vs. 16.8%, p = 0.02) and antibiotics (8.2% vs. 0.7%, p = 0.001), and were more likely to be pregnant (9.1% vs. 3.6%, p = 0.04) than the culture-negative women. Dyspareunia was more frequent in women without Candida (38.0% vs. 28.3%, p = 0.03) while vaginal erythema (p = 0.01) was more common in women with a positive Candida culture. Conclusions: Although quantitative differences were observed, the presence of vaginal Candida vulvovaginitis cannot be definitively identified by clinical criteria

Particulate Matter and Labor Supply: The Role of Caregiving and Non-Linearities

This paper examines the effect of air pollution on labor supply in Lima, Peru. We focus on fine particulate matter (PM2.5), an important pollutant for health according to the medical literature, and show that moderate levels of pollution reduce hours worked for working adults. Our research design takes advantage of rich household panel data in labor outcomes to address omitted variables. This research design allows us to investigate whether the response to air pollution is non-linear. We find that the effect of moderate pollution levels on hours worked is concentrated among households with susceptible dependents, i.e., small children and elderly adults; while the highest concentrations affect all households. This suggests that caregiving is likely a mechanism linking air pollution to labor supply at moderate levels. We provide further evidence of this mechanism using data on children morbidity. Finally, we find no evidence of intra-household attenuation behavior. For instance, there is no re-allocation of labor across household members, and earnings decrease with air pollution.&nbsp

Determinants of The Fear of The Pandemic and Its Effect on Voting Behavior Among Young Adult Filipinos in The Next Presidential Election

With COVID-19 severely impacting several aspects of society, the upcoming 2022 Philippine Presidential Elections will be the first to take place under such unique circumstances. This study provides information on how various determinants of fear of COVID-19 affect the voting behavior of young adult Filipinos. This study utilized a survey consisting of five sections composed of sociodemographic questionnaire, Multidimensional Scale of Perceived Social Support, Core Dimensions of Spirituality Questionnaire, Fear of COVID-19 Scale and a question about political participation. The results showed that individuals with a higher level of social support and higher level of spirituality were more likely to conform to the political ideals of their respective environments (i.e. family & religious institutions) and were more likely to participate in the elections, along with individuals with higher levels of fea