2,039 research outputs found

    Virus-like particle distribution and abundance in sediments and overlying waters along eutrophication gradients in two subtropical estuaries

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    Viruses are recognized as ubiquitous components of marine ecosystems; however, there has been limited study of viral abundance and its ecological role in sediments. Viral abundance was determined in both the water column and sediments of a eutrophic (Brisbane River/Moreton Bay; 27°25′S, 153°5′E) and oligotrophic (Noosa River; 26°15′S, 153°0′E) estuary in subtropical Queensland, Australia. Viruses, bacteria, and microalgae from both water column and extracted sediment samples were enumerated using SYBR Green I staining and epifluorescence microscopy. Sediment viral abundance ranged from 10 to 10 particles cm of sediment, bacterial abundance ranged from 10 to 10 cells cm of sediment, and microalgal abundance ranged from 10 to 10 cells cm sediment. Pelagic abundances for all microorganisms were 10-1,000-fold lower than sediment abundances. Correlations between viral abundances and suspended solids suggest that viruses sorbed to suspended material in the water column may settle out and contribute to the benthic viral population. Virus production was measured by a time course increase of viral abundance in seawater using a dilution technique. Virus production was highest in eutrophic waters of the Brisbane River, and addition of inorganic nutrients (NO + NH + PO + SiO) stimulated viral production rates at all stations by 14-52% above ambient, suggesting that inorganic nutrient availability may play a key role in aquatic viral abundance

    Building Bridges: Improving Extension Support to Organic Growers in North Georgia

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    Organic agriculture has the potential to improve the environmental performance of U.S. agriculture, supporting increasing food demand and diversification of food consumption while improving the quality of ecosystems. Organic growers are challenged by a lack of Cooperative Extension agent support as agents have not served organic growers to the same extent as conventional growers nationwide. Rogers’ (2003) diffusion of innovations theory guided our phenomenological inquiry to explore (a) what agents experienced while supporting organic growers, and (b) how agents experienced providing support to organic growers in north Georgia. According to participants, the essence of the support offered to organic growers was an uneven bridge. Agents were willing to provide growers with the resources to support organic production; however, they lacked theoretical and empirical knowledge regarding organic agricultural production that would enable them to establish stronger relationships with growers. Findings from the study and the uneven bridge metaphor led to an original model to assist Extension agents in better serving the organic agricultural community

    Chest computed tomography findings in HIV-infected individuals in the era of antiretroviral therapy

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    Background: Chest radiographic abnormalities were common in HIV-infected individuals in the pre-combination antiretroviral therapy era, but findings may differ now due to a changing spectrum of pulmonary complications. Copyright

    Novel virus dynamics in an Emiliania huxleyi bloom

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    Diel studies of an Emiliania huxleyi bloom within a mesocosm revealed a highly dynamic associated viral community, changing on small times scales of hours

    Pulmonary fissure integrity and collateral ventilation in COPD patients

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    Purpose: To investigate whether the integrity (completeness) of pulmonary fissures affects pulmonary function in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods: A dataset consisting of 573 CT exams acquired on different subjects was collected from a COPD study. According to the global initiative for chronic obstructive lung disease (GOLD) criteria, these subjects (examinations) were classified into five different subgroups, namely non-COPD (222 subjects), GOLD-I (83 subjects), GOLD-II (141 subjects), GOLD-III (63 subjects), and GOLD-IV (64 subjects), in terms of disease severity. An available computer tool was used to aid in an objective and efficient quantification of fissure integrity. The correlations between fissure integrity, and pulmonary functions (e.g., FEV1, and FEV1/FVC) and COPD severity were assessed using Pearson and Spearman's correlation coefficients, respectively. Results: For the five sub-groups ranging from non-COPD to GOLD-IV, the average integrities of the right oblique fissure (ROF) were 81.8%, 82.4%, 81.8%, 82.8%, and 80.2%, respectively; the average integrities of the right horizontal fissure (RHF) were 62.6%, 61.8%, 62.1%, 62.2%, and 62.3%, respectively; the average integrities of the left oblique fissure (LOF) were 82.0%, 83.2%, 81.7%, 82.0%, and 78.4%, respectively; and the average integrities of all fissures in the entire lung were 78.0%, 78.6%, 78.1%, 78.5%, and 76.4%, respectively. Their Pearson correlation coefficients with FEV1 and FE1/FVC range from 0.027 to 0.248 with p values larger than 0.05. Their Spearman correlation coefficients with COPD severity except GOLD-IV range from -0.013 to -0.073 with p values larger than 0.08. Conclusion: There is no significant difference in fissure integrity for patients with different levels of disease severity, suggesting that the development of COPD does not change the completeness of pulmonary fissures and incomplete fissures alone may not contribute to the collateral ventilation. © 2014 Pu et al
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