Elms College

About: Elms College is a education organization based out in Chicopee, Massachusetts, United States. It is known for research contribution in the topics: Melatonin & Population. The organization has 102 authors who have published 92 publications receiving 1527 citations. The organization is also known as: College of Our Lady of the Elms.

Changing attitudes through intergroup contact: the effects of group membership salience

Abstract: Two studies were conducted to test the hypothesis that heightened membership salience, achieved by increasing the prototypicality of particular outgroup members during cooperative intergroup contact, facilitates the generalization of positive attitudes toward the outgroup as a whole. The first study (N = 64) utilized an experimental paradigm in which the perceived typicality of a target outgroup member and the perceived homogeneity of the outgroup as a whole were manipulated. Consistent with our hypothesis, results indicated that positive attitudinal generalization was facilitated by encounters with typical outgroup members. The effects of membership prototypicality were further examined in a second study (N = 293) where a survey was administered in six European Community countries. Results supported the hypothesis that membership salience moderates the impact of contact on a generalized measure of favourable orientation towards another country. Copyright (C) 1999 John Wiley & Sons, Ltd.

Review on the epidemiology and dynamics of BSE epidemics.

Abstract: The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7, 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also showed the discrepancy of this passive surveillance efficiency between regions and production types (dairy/beef). Other risk factors for BSE were being in a dairy herd (three times more than beef), having a young age at first calving (for dairy cattle), being autumn-born (dairy and beef), and being in a herd with a very high milk yield. These findings focus the risk on the feeding regimen of calves/heifers. Several epidemiological studies across countries suggest that the feedborne source related to meat and bone meal (MBM) is the only substantiated route of infection - even after the feed ban -, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections. In most European countries, the average age of the cases is increasing over time and the prevalence decreasing, which reflects the effectiveness of control measures. Consistent results on the trend of the epidemic were obtained using back-calculation modelling, the R(0) approach and Age-Period-Cohort models. Furthermore, active surveillance also resulted in the finding of atypical cases. These are distinct from previously found BSE and classified in two different forms based on biochemical characteristics; their prevalence is very low (36 cases up to 1st September 2007), affected animals were old and some of them displayed clinical signs. The origin and possibility of natural transmission is unknown.

Herbivory reduces plant interactions with above- and belowground antagonists and mutualists

Abstract: Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss.

Linking agricultural practices, mycorrhizal fungi, and traits mediating plant–insect interactions

Abstract: Agricultural management has profound effects on soil communities. Activities such as fertilizer inputs can modify the composition of arbuscular mycorrhizal fungi (AMF) communities, which form important symbioses with the roots of most crop plants. Intensive conventional agricultural management may select for less mutualistic AMF with reduced benefits to host plants compared to organic management, but these differences are poorly understood. AMF are generally evaluated based on their direct growth effects on plants. However, mycorrhizal colonization also may alter plant traits such as tissue nutrients, defensive chemistry, or floral traits, which mediate important plant-insect interactions like herbivory and pollination. To determine the effect of AMF from different farming practices on plant performance and traits that putatively mediate species interactions, we performed a greenhouse study by inoculating Cucumis sativus (cucumber, Cucurbitaceae) with AMF from conventional farms, organic farms, and a commercial AMF inoculum. We measured growth and a suite of plant traits hypothesized to be important predictors of herbivore resistance and pollinator attraction. Several leaf and root traits and flower production were significantly affected by AMF inoculum. Both conventional and organic AMF reduced leaf P content but increased Na content compared to control and commercial AMF. Leaf defenses were unaffected by AMF treatments, but conventional AMF increased root cucurbitacin C, the primary defensive chemical of C. sativus, compared to organic AMF. These effects may have important consequences for herbivore preference and population dynamics. AMF from both organic and conventional farms decreased flower production relative to commercial and control treatments, which may reduce pollinator attraction and plant reproduction. AMF from both farm types also reduced seed germination, but effects on plant growth were limited. Our results suggest that studies only considering AMF effects on growth may overlook changes in plant traits that have the potential to influence interactions, and hence yield, on farms. Given the effects of AMF on plant traits documented here, and the great importance of both herbivores and pollinators to wild and cultivated plants, we advocate for comprehensive assessments of mycorrhizal effects in complex community contexts, with the aim of incorporating multispecies interactions both above and below the soil surface.