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Agricultural Settings (agricultural + setting)
Selected AbstractsPollinator genetics and pollination: do honey bee colonies selected for pollen-hoarding field better pollinators of cranberry Vaccinium macrocarpon?ECOLOGICAL ENTOMOLOGY, Issue 2 2001James H. Cane Summary 1. Genetic polymorphisms of flowering plants can influence pollinator foraging but it is not known whether heritable foraging polymorphisms of pollinators influence their pollination efficacies. Honey bees Apis mellifera L. visit cranberry flowers for nectar but rarely for pollen when alternative preferred flowers grow nearby. 2. Cranberry flowers visited once by pollen-foraging honey bees received four-fold more stigmatic pollen than flowers visited by mere nectar-foragers (excluding nectar thieves). Manual greenhouse pollinations with fixed numbers of pollen tetrads (0, 2, 4, 8, 16, 32) achieved maximal fruit set with just eight pollen tetrads. Pollen-foraging honey bees yielded a calculated 63% more berries than equal numbers of non-thieving nectar-foragers, even though both classes of forager made stigmatic contact. 3. Colonies headed by queens of a pollen-hoarding genotype fielded significantly more pollen-foraging trips than standard commercial genotypes, as did hives fitted with permanently engaged pollen traps or colonies containing more larvae. Pollen-hoarding colonies together brought back twice as many cranberry pollen loads as control colonies, which was marginally significant despite marked daily variation in the proportion of collected pollen that was cranberry. 4. Caloric supplementation of matched, paired colonies failed to enhance pollen foraging despite the meagre nectar yields of individual cranberry flowers. 5. Heritable behavioural polymorphisms of the honey bee, such as pollen-hoarding, can enhance fruit and seed set by a floral host (e.g. cranberry), but only if more preferred pollen hosts are absent or rare. Otherwise, honey bees' broad polylecty, flight range, and daily idiosyncrasies in floral fidelity will obscure specific pollen-foraging differences at a given floral host, even among paired colonies in a seemingly uniform agricultural setting. [source] Work, Identity, and Stigma Management in an Italian Mental Health CommunityANTHROPOLOGY OF WORK REVIEW, Issue 1 2006Sara M. Bergstresser Abstract When mental illness prevents an individual from working, the economic burden is obvious, but little attention has been paid to the accompanying loss of social identity. This paper addresses the meanings of work and unemployment for participants in an Italian community mental health center, and it evaluates the role of work therapy in an agricultural setting as a way to regain some social aspects of work or professional identity. The study is based on over a year of anthropological fieldwork in the Province of Bergamo, Northern Italy, conducted to investigate the relationship between community-based mental health care, social stigma of mental illness, and the social sphere in everyday life. The social position of the individual at the time of job loss is significant in his or her professional expectations while in the community center. Those who had previously worked in manual or farming capacities found this type of work therapy to be a helpful means of social participation. On the other hand, expectations based on educational, social, and economic hierarchies persist for individuals within mental health communities. For those individuals with high education, manual labor violated professional expectations, and the reality of their employability provided a conflict between social participation and perceived status group. The stigma of unemployment is also addressed in relation to political identity and desire for worker status. [source] Pluronics' influence on pseudomonad biofilm and phenazine productionFEMS MICROBIOLOGY LETTERS, Issue 1 2009Lindsay Housley Abstract Colonization of roots by Pseudomonas chlororaphis O6 (PcO6) involves root surface coverage through surface motility and biofilm formation. Root colonization and the production of antifungal phenazines are important in the ability of the bacterium to protect plants against pathogens. In this in vitro study we report that both biofilm formation and phenazine production are differentially influenced by nutrition and the presence of polyethylene oxide/polypropylene oxide triblock copolymer surfactants (Pluronics). Such surfactants are used for many purposes including agricultural formulations. Four Pluronics differing in molecular weight and in hydrophobic/hydrophilic proportions had distinct effects on biofilm formation and secondary metabolite production, although each increased surface motility, termed swarming, to a similar extent. These findings show that Pluronics had specific metabolic impacts on the bacterium, where both up- and downregulation was achieved depending on the medium and the Pluronic composition. In environmental and agricultural settings, Pluronics may have unanticipated effects on soil microorganisms, while in bioprocessing these effects may be leveraged to regulate metabolite yield. [source] Beehive fence deters crop-raiding elephantsAFRICAN JOURNAL OF ECOLOGY, Issue 2 2009Lucy E. King Abstract Previous work has shown that African elephants Loxodonta africana will avoid African honeybees Apis mellifera scutellata. Here we present results from a pilot study conducted to evaluate the concept of using beehives to mitigate elephant crop depredation. In Laikipia, Kenya, we deployed a 90-m fence-line of nine inter-connected hives, all empty, on two exposed sides of a square two-acre farm that was experiencing high levels of elephant crop depredation. Compared with a nearby control farm of similar status and size, our experimental farm experienced fewer raids and consequently had higher productivity. Socioeconomic indicators suggest that not only was the concept of a beehive fence popular and desired by the community but also that it can pay for its construction costs through the sale of honey and bee products. We are calling for experiments testing this concept of a ,guardian beehive-fence' to be conducted rigorously and scientifically in as wide a range of agricultural settings as possible to evaluate jointly its effectiveness and efficiency. Résumé Des travaux antérieurs ont montré que les éléphants africains Loxodonta africanaévitent les abeilles africaines Apis mellifera scutellata. Nous présentons ici les résultats d'une étude pilote réalisée pour évaluer le concept consistant à utiliser des ruches pour réduire la destruction des cultures par les éléphants. A Laikipia, au Kenya, nous avons installé une barrière de 90 m. de long composée de neuf ruches interconnectées, toutes vides, sur deux côtés exposés d'une ferme carrée de deux acres (arpents) dont les cultures subissaient une forte déprédation causée par les éléphants. Comparée à une ferme contrôle voisine, de statut et de taille comparables, notre ferme expérimentale a subi moins de raids et a donc eu une meilleure productivité. Des indicateurs socioéconomiques suggèrent que non seulement le concept de barrière en ruches était populaire et souhaité par la communauté, mais qu'il peut même couvrir les frais de sa propre construction grâce à la vente de miel et autres produits dérivés. Nous sollicitons que des expériences soient faites pour tester ce concept de « clôture en ruches » de façon rigoureuse et scientifique, dans une gamme aussi étendue que possible d'installations agricoles, afin d'évaluer son efficacité et sa faisabilité. [source] Targeted sugar provision promotes parasitism of the cereal leaf beetle Oulema melanopusAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2010Edward W. Evans 1Parasitoids may often lack access to sugar (e.g. floral nectar) in agricultural settings. Strategically timed spraying of host plants with sugar solution may provide one means of enhancing parasitism at the same time as minimizing nontarget effects (e.g. benefiting the pest itself). 2Sucrose was sprayed in wheat fields of northern Utah (U.S.A.) to assess the effects on parasitism of the cereal leaf beetle Oulema melanopus by the larval parasitoid Tetrastichus julis. 3Early-season sugar provisioning, when larvae of the pest were first hatching and parasitoid adults were newly emerged, did not affect the numbers of cereal leaf beetle larvae that matured in treated plots but increased parasitism rates of beetle larvae by four-fold in 2006 and by seven-fold in 2007. 4No net influx of adult parasitoids into plots was detected after the application of sugar. Locally-emerging parasitoids may have spent less time searching for their own food needs versus hosts. A laboratory experiment also confirmed that access to sucrose significantly increased parasitoid longevity. 5The field experimental results obtained demonstrate that applications of sugar, implemented to target a key time of the growing season when benefits are maximized for parasitoids and minimized for their hosts, can strongly promote parasitism of the cereal leaf beetle in wheat fields. [source] STATEWIDE EMPIRICAL MODELING OF BACTERIAL CONTAMINATION OF SURFACE WATERS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006James D. Wickham ABSTRACT: Bacterial contamination of surface waters is attributed to both urban and agricultural land use practices and is one of the most frequently cited reasons for failure to meet standards established under the Clean Water Act (CWA) (P.L. 92,500). Statewide modeling can be used to determine if bacterial contamination occurs predominantly in urban or agricultural settings. Such information is useful for directing future monitoring and allocating resources for protection and restoration activities. Logistic regression was used to model the likelihood of bacterial contamination using watershed factors for the state of Maryland. Watershed factors included land cover, soils, topography, hydrography, locations of septic systems, and animal feeding operations. Results indicated that bacterial contamination occurred predominantly in urban settings. Likelihood of bacterial contamination was highest for small watersheds with well drained and erodible soils and a high proportion of urban land adjacent to streams. The number of septic systems and animal feeding operations and the amount of agricultural land were not significant explanatory factors. The urban infrastructure tends to "connect" more of the watershed to the stream network through the creation of roads, storm sewers, and wastewater treatment plants. This may partly explain the relationship between urbanization and bacterial contamination found in this study. [source] Nanodisks protect amphotericin B from ultraviolet light and oxidation-induced damagePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2009Megan L Tufteland Abstract BACKGROUND: Macrolide polyene antibiotics possess potent broad-spectrum antifungal properties. Use of these agents in the field or in controlled environments is impeded by their poor water solubility and susceptibility to oxidation- and/or light-induced degradation. While typically used for human disease therapy, there is potential to expand the utility of polyene macrolide antibiotics, such as amphotericin B, for control of fungal disease infestation in agricultural settings. Thus, the susceptibility of this antibiotic to exposure-induced activity loss was evaluated. RESULTS: Incubation of the prototype polyene amphotericin B (AMB) with phospholipid vesicles and apolipoprotein A-I results in the formation of nanoscale complexes, termed nanodisks (NDs), capable of solubilizing significant quantities of AMB. To evaluate whether AMB incorporation into NDs conferred protection against light- or oxidation-induced damage, yeast growth inhibition assays were conducted. Compared with AMB solubilized in detergent micelles, AMB incorporated into NDs was protected from damage caused by exposure to UV light as well as by KMnO4 -induced oxidation. Furthermore, AMB-NDs inhibited growth of the turfgrass fungus Marasmius oreades Fr. CONCLUSION: Results suggest that this water-soluble formulation of a natural, biodegradable, antifungal agent represents a potential cost-effective, non-toxic and environmentally friendly substitute for chemical agents currently employed to control a range of fungal infestations. Copyright © 2009 Society of Chemical Industry [source] Cluster of presumed organic dust toxic syndrome cases among urban landscape workers,Colorado, 2007,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2009Tegan K. Boehmer PhD Abstract Background Organic dust toxic syndrome (ODTS) is an influenza-like illness typically affecting agricultural workers exposed to organic dusts. In July 2007, Tri-County Health Department investigated a cluster of acute respiratory illnesses among urban landscape workers with known mulch exposure. Methods An epidemiologic study of landscape workers was conducted. Employees were interviewed regarding illness and occupational exposures. Medical records were reviewed. Mulch samples were tested for fungi and endotoxins. Results Five (12%) of 43 employees experienced respiratory illness compatible with ODTS. Illness was associated with prolonged mulch exposure (,6 vs. <6 hr/day; relative risk,=,24.7; 95% confidence interval,=,3.3,184.9). Mulch samples contained high levels of Aspergillus spores and endotoxin. Conclusions Contaminated mulch was implicated as the source of presumed ODTS among landscape workers, highlighting that ODTS is not limited to rural agricultural settings. Education of employers, safety officers, and clinicians is necessary to improve recognition and prevention of ODTS within urban occupational groups. Am. J. Ind. Med. 52:534,538, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||