652 research outputs found

    Evidence of late Quaternary environmental change in a continental east Antarctic lake from lacustrine sedimentary pigment distributions

    Get PDF
    A sediment core from Progress Lake, one of the oldest lacustrine sequences in East Antarctica, contains distinct zones dating from a previous interglacial (most likely Marine Isotope Stage 5e, c. 125-115 kyr BP) and the present interglacial (Marine Isotope Stage 1), separated by a transition zone representing when the lake became sub-glacial. Profiles of fossil pigments, determined using high performance liquid chromatography and liquid chromatography-tandem mass spectrometry, show distinct differences in the photoautotrophic community during these two interglacial periods. The first was dominated by algae and purple phototrophic bacteria, with periods of photic zone euxinia indicated by pigments from anoxygenic phototrophic bacteria. Specific chlorophyll a derivatives reveal periods when grazing pressure impacted significantly on the phytoplankton community. The virtual absence of pigments in the transition zone reflects severe restriction of photoautotrophic activity, consistent with the take having become sub-glacial. Retreat of snow and ice in the late Holocene (3345 C-14 yr Bp) allowed establishment of a less diverse primary producer community, restricted to algae and cyanobacteria. Grazers were severely restricted and oxidative transformation was more important than during the previous interglacial. The pigment data provide a unique and detailed insight in to the evolution of the lake ecology over an interglacial-glacial-interglacial transition and strong evidence that the Marine Isotope Stage 5e interglacial in this region of coastal East Antarctica was several degrees warmer than at present

    Through the doors of the wardrobe: A qualitative case study of a short-term study abroad program inspired by the C.S. Lewis Trail in Ireland

    Get PDF
    This qualitative case study explores experiences of U.S. American undergraduate students who participated in a short-term study abroad program to the Republic of Ireland and Northern Ireland. The program focused on psychological perspectives of childhood and play including restorative benefits of spending time in nature. Additional features of the program included using a children’s novel to connect class content and travels as well as prioritizing outdoor experiences. Students shared reflections on their experiences through digital storytelling projects and interviews. Analysis of data resulted in identification of five themes and researcher assertions. The study is framed in relation to literature contrasting short-term and long-term study abroad and the use of reflective practices including digital storytelling in study abroad

    Isolated prehospital hypotension correlates with injury severity and outcomes in patients with trauma

    Get PDF
    Objective Patients normotensive in the trauma bay despite documented prehospital hypotension may not be recognized as significantly injured. The purpose of this study was to determine whether isolated prehospital hypotension portends poor outcomes and correlates with injury severity. Methods Prospective cohort study conducted at a level 1 university trauma center. The lowest recorded prehospital systolic blood pressure (SBP) and the first recorded SBP on hospital arrival were used to divide patients into either the normotensive (NP) or hypotensive (HP) group. Patients who failed to achieve normotension on hospital arrival were excluded. Hypotension was defined as SBP≤110 mmHg. Results Compared to NP (n=206), HP (n=81) had lower Glasgow Coma Scores both prehospital (12.81±0.44 vs 14.38±0.13) and at hospital admission (12.78±0.47 vs 14.37±0.14). Injury Severity Score positively correlated with prehospital hypotension (HP 12.27±1.12 vs NP 9.22±0.49). Prehospital hypotension positively correlated with intensive care unit (ICU) admission (HP 56.79% vs NP 22.82%), ICU length of stay (LOS) (HP 3.23±0.71 vs NP 0.71±0.17), hospital LOS (HP 8.58±1.39 vs NP 4.86±0.33), ventilator days (HP 3.38±1.20 vs NP 0.27±0.08 days), and repeat hypotensive episodes during their hospital stay (HP 81.71% vs NP 38.16%). HP also required more packed red blood cells in the first 24 hours after admission (22% vs 6%). Significance was set at p\u3c0.05. Conclusions Isolated prehospital hypotension in patients in the trauma and emergency department correlates with increased injury severity and portends worse outcomes despite a normal blood pressure reading at admission. Prehospital hypotension must be given heavy consideration in triage, as these patients may be transiently hypotensive and appear less critical than their true status. Level of Evidence Level II, Prognostic study

    Single cell PCR amplification of diatoms using fresh and preserved samples

    Get PDF
    Single cell Chelex® DNA extraction and nested PCR amplification were used to examine partial gene sequences from natural diatom populations for taxonomic and phylogenetic studies at and above the level of species. DNA was extracted from cells that were either fresh collected or stored in RNAlater. Extractions from Lugol’s fixation were also attempted with limited success. Three partial gene sequences (rbcL, 18S and psbA) were recovered using existing and new primers with a nested or double nested PCR approach with amplification and success rates between 70–96%. An rbcL consensus tree grouped morphologically similar specimens and was consistent across the two primary sample treatments: fresh and RNAlater. This tool will greatly enhance the number of microscopic diatom taxa (and potentially other microbes) available for barcoding and phylogenetic studies. The near-term increase in sequence data for diatoms generated via routine single cell extractions and PCR will act as a multiproxy validation of longer-term next generation genomics

    Exploring the Impact of a Positive Psychology and Creative Journal Arts Intervention with Latina/o Adolescents

    Get PDF
    A creative journal arts and positive psychology intervention was utilized to explore resilience, personal recovery attitudes, and symptoms of depression in Latina/o adolescents. The impact of a seven-week group counseling experience conducted with adolescents was analyzed and revealed positive improvements for participants in all three areas. Benefits for Latina/o youth participating in this type of group are discussed and guidelines for school counselors and clinical mental health counselors are revealed

    Evaluating diverse electronic consultation programs with a common framework.

    Get PDF
    BackgroundElectronic consultation is an emerging mode of specialty care delivery that allows primary care providers and their patients to obtain specialist expertise without an in-person visit. While studies of individual programs have demonstrated benefits related to timely access to specialty care, electronic consultation programs have not achieved widespread use in the United States. The lack of common evaluation metrics across health systems and concerns related to the generalizability of existing evaluation efforts may be hampering further growth. We sought to identify gaps in knowledge related to the implementation of electronic consultation programs and develop a set of shared evaluation measures to promote further diffusion.MethodsUsing a case study approach, we apply the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) and the Quadruple Aim frameworks of evaluation to examine electronic consultation implementation across diverse delivery systems. Data are from 4 early adopter healthcare delivery systems (San Francisco Health Network, Mayo Clinic, Veterans Administration, Champlain Local Health Integration Network) that represent varied organizational structures, care for different patient populations, and have well-established multi-specialty electronic consultation programs. Data sources include published and unpublished quantitative data from each electronic consultation database and qualitative data from systems' end-users.ResultsOrganizational drivers of electronic consultation implementation were similar across the systems (challenges with timely and/or efficient access to specialty care), though unique system-level facilitators and barriers influenced reach, adoption and design. Effectiveness of implementation was consistent, with improved patient access to timely, perceived high-quality specialty expertise with few negative consequences, garnering high satisfaction among end-users. Data about patient-specific clinical outcomes are lacking, as are policies that provide guidance on the legal implications of electronic consultation and ideal remuneration strategies.ConclusionA core set of effectiveness and implementation metrics rooted in the Quadruple Aim may promote data-driven improvements and further diffusion of successful electronic consultation programs

    Aging impacts isolated lymphoid follicle development and function

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Immunosenescence is the age-related decline and dysfunction of protective immunity leading to a marked increase in the risk of infections, autoimmune disease, and cancer. The majority of studies have focused on immunosenescence in the systemic immune system; information concerning the effect of aging on intestinal immunity is limited. Isolated lymphoid follicles (ILFs) are newly appreciated dynamic intestinal lymphoid structures that arise from nascent lymphoid tissues, or cryptopatches (CP), in response to local inflammatory stimuli. ILFs promote "homeostatic" responses including the production of antigen-specific IgA, thus playing a key role in mucosal immune protection. ILF dysfunction with aging could contribute to immunosenescence of the mucosal system, and accordingly we examined phenotypic and functional aspects of ILFs from young (2 month old) and aged (2 year old) mice.</p> <p>Results</p> <p>We observed that aged mice have increased numbers of ILFs and increased numbers of structures corresponding to an early stage of CPs transforming into ILFs. The cellular composition of ILFs in aged mice is altered with a smaller B-lymphocyte population and an increased T-lymphocyte population. The ILF T-lymphocyte population is notable by the presence of CD4+ CD8αα+ T-lymphocytes, which are absent from the systemic compartment. The smaller B-lymphocyte population in ILFs from aged mice is directly correlated with decreased mRNA and protein expression of CCL20 and CXCL13, two chemokines that play crucial roles in recruiting B-lymphocytes into ILFs. Aged mice had elevated levels of serum and fecal immunoglobulins and despite the decreased B-lymphocyte population, ILFs from aged mice displayed increased IgA production. The immunoglobulin repertoire was skewed in aged mice, and ILFs demonstrated a repertoire usage similar to that of the systemic pool in both young and aged mice.</p> <p>Conclusions</p> <p>Here we observed that ILF development, cellular composition, and immunoglobulin production are altered with aging suggesting that ILF dysfunction contributes to mucosal immunosenescence.</p
    corecore