791 research outputs found

    Reproduction and Dispersal of Biological Soil Crust Organisms

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    Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms—including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups that make up BSC communities in various and unique combinations include—free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. The various BSC organismal groups demonstrate several common characteristics including—desiccation and extreme temperature tolerance, production of various soil binding chemistries, a near exclusive dependency on asexual reproduction, a pattern of aerial dispersal over impressive distances, and a universal vulnerability to a wide range of human-related perturbations. With this publication, we provide literature-based insights as to how each organismal group contributes to the formation and maintenance of the structural and functional attributes of BSCs, how they reproduce, and how they are dispersed. We also emphasize the importance of effective application of molecular and microenvironment sampling and assessment tools in order to provide cogent and essential answers that will allow scientists and land managers to better understand and manage the biodiversity and functional relationships of soil crust communities

    Dose Effects of Encapsulated Butyric Acid and Zinc on Beef Feedlot Steer Growth Performance, Carcass Characteristics, and Dietary Net Energy Utilization

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    Study Description: Steers (n = 272; shrunk BW = 794 ± 163 pounds) were assigned to one of four dietary treatments in a 143.5 d feedlot finishing trial: 0 g BPZ/ kg diet dry matter (DM) (CON), 1 g BPZ/ kg diet DM (1BPZ), 2 g BPZ/ kg diet DM (2BPZ), or 3 g BPZ/ kg diet DM (3BPZ). Carcass data and liver health outcomes were collected, and feedlot growth performance data and efficiency of dietary net energy utilization were calculated on a carcass-adjusted basis

    Enhancing effective healthcare communication in Australia and Aotearoa New Zealand: Considerations for research, teaching, policy, and practice.

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    OBJECTIVE In this article we present a conceptual framework for enhancing effective healthcare communication in Australia and Aotearoa New Zealand. METHODS Through an iterative, deliberative dialogue approach, we, as experts from a variety of health professions and academic disciplines, worked together to identify core values and considerations for healthcare communication across numerous health professions and disciplines and within research, teaching, policy, and practice contexts. RESULTS The framework developed includes five core values at its centre: equitable, inclusive, evidence-based, collaborative, reflective. Around this are concentric circles showing key elements of collaborators, modality, context, and purpose. Each of these is explored. CONCLUSION This work may support benchmarking for healthcare providers, researchers, policymakers, and educators across a breadth of professions to help improve communication in clinical practice. The framework will also help to identify areas across disciplines that are shared and potentially idiosyncratic for various professions to promote interprofessional recognition, education, and collaboration. INNOVATION This framework is designed to start conversations, to form the foundation of a dialogue about the priorities and key considerations for developing teaching curricula, professional development, and research programs related to healthcare communication, providing a set of values specifically for the unique contexts of Australia and Aotearoa New Zealand. It can also be used to guide interdisciplinary healthcare professionals in advancing research, teaching, policy, and practice related to healthcare communication

    Early Spring Phytoplankton Dynamics in the Western Antarctic Peninsula

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    The Palmer Long-Term Ecological Research program has sampled waters of the western Antarctic Peninsula (wAP) annually each summer since 1990. However, information about the wAP prior to the peak of the phytoplankton bloom in January is sparse. Here we present results from a spring process cruise that sampled the wAP in the early stages of phytoplankton bloom development in 2014. Sea ice concentrations were high on the shelf relative to nonshelf waters, especially toward the south. Macronutrients were high and nonlimiting to phytoplankton growth in both shelf and nonshelf waters, while dissolved iron concentrations were high only on the shelf. Phytoplankton were in good physiological condition throughout the wAP, although biomass on the shelf was uniformly low, presumably because of heavy sea ice cover. In contrast, an early stage phytoplankton bloom was observed beneath variable sea ice cover just seaward of the shelf break. Chlorophyll a concentrations in the bloom reached 2 mg m^(−3) within a 100–150 km band between the SBACC and SACCF. The location of the bloom appeared to be controlled by a balance between enhanced vertical mixing at the position of the two fronts and increased stratification due to melting sea ice between them. Unlike summer, when diatoms overwhelmingly dominate the phytoplankton population of the wAP, the haptophyte Phaeocystis antarctica dominated in spring, although diatoms were common. These results suggest that factors controlling phytoplankton abundance and composition change seasonally and may differentially affect phytoplankton populations as environmental conditions within the wAP region continue to change

    HIV specific CD8+ TRM-like cells in tonsils express exhaustive signatures in the absence of natural HIV control

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    Lymphoid tissues are an important HIV reservoir site that persists in the face of antiretroviral therapy and natural immunity. Targeting these reservoirs by harnessing the antiviral activity of local tissue-resident memory (TRM) CD8+ T-cells is of great interest, but limited data exist on TRM-like cells within lymph nodes of people living with HIV (PLWH). Here, we studied tonsil CD8+ T-cells obtained from PLWH and uninfected controls from South Africa. We show that these cells are preferentially located outside the germinal centers (GCs), the main reservoir site for HIV, and display a low cytolytic and a transcriptionally TRM-like profile distinct from blood CD8+ T-cells. In PLWH, CD8+ TRM-like cells are expanded and adopt a more cytolytic, activated, and exhausted phenotype not reversed by antiretroviral therapy (ART). This phenotype was enhanced in HIV-specific CD8+ T-cells from tonsils compared to matched blood suggesting a higher antigen burden in tonsils. Single-cell transcriptional and clonotype resolution showed that these HIV-specific CD8+ T-cells in the tonsils express heterogeneous signatures of T-cell activation, clonal expansion, and exhaustion ex-vivo. Interestingly, this signature was absent in a natural HIV controller, who expressed lower PD-1 and CXCR5 levels and reduced transcriptional evidence of T-cell activation, exhaustion, and cytolytic activity. These data provide important insights into lymphoid tissue-derived HIV-specific CD8+ TRM-like phenotypes in settings of HIV remission and highlight their potential for immunotherapy and targeting of the HIV reservoirs
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