475 research outputs found
Adaptation to ephemeral habitat may overcome natural barriers and severe habitat fragmentation in a fire-dependent species, the Bachman\u27s Sparrow (Peucaea aestivalis)
Bachman\u27s Sparrow (Peucaea aestivalis) is a fire-dependent species that has undergone range-wide population declines in recent decades. We examined genetic diversity in Bachman\u27s Sparrows to determine whether natural barriers have led to distinct population units and to assess the effect of anthropogenic habitat loss and fragmentation. Genetic diversity was examined across the geographic range by genotyping 226 individuals at 18 microsatellite loci and sequencing 48 individuals at mitochondrial and nuclear genes. Multiple analyses consistently demonstrated little genetic structure and high levels of genetic variation, suggesting that populations are panmictic. Based on these genetic data, separate management units/subspecies designations or translocations to promote gene flow among fragmented populations do not appear to be necessary. Panmixia in Bachman\u27s Sparrow may be a consequence of an historical range expansion and retraction. Alternatively, high vagility in Bachman\u27s Sparrow may be an adaptation to the ephemeral, fire-mediated habitat that this species prefers. In recent times, high vagility also appears to have offset inbreeding and loss of genetic diversity in highly fragmented habitat. © 2014 Cerame et al
Survey of University of California Academics\u27 Attitudes Regarding the Impact of Escaped Horticultural Introductions on Wildlands
In order to investigate whether there were differences in attitudes and perceptions within the University of California regarding the impact of introduced ornamental plants, we conducted a survey of academics with assignments in natural resource programs or ornamental horticulture. In general, the ornamental horticulture academics did not view the problem of invasive species as severely as the natural resource academics, but the both groups recognize that non-native landscape ornamentals now occur and can affect California\u27s wildlands. These data can be used to provide training to academics on this issue and help facilitate discussion between the different groups
Efficiency of primary spine care as compared to conventional primary care: a retrospective observational study at an Academic Medical Center
Background: Primary Spine Care (PSC) is an innovative model for the primary management of patients with spine-related disorders (SRDs), with a focus on the use of non-pharmacological therapies which now constitute the recommended first-line approach to back pain. PSC clinicians serve as the initial or early point of contact for spine patients and utilize evidence-based spine care pathways to improve outcomes and reduce escalation of care (EoC; e.g., spinal injections, diagnostic imaging, hospitalizations, referrals to a specialist). The present study examined 6-month outcomes to evaluate the efficiency of care for patients who received PSC as compared to conventional primary care. We hypothesized that patients seen by a PSC clinician would have lower rates of EoC compared to patients who received usual care by a primary care (PC) clinician. Methods: This was a retrospective observational study. We evaluated 6-month outcomes for two groups seen and treated for an SRD between February 01, 2017 and January 31, 2020. Patient groups were comprised of N = 1363 PSC patients (Group A) and N = 1329 PC patients (Group B). We conducted Pearson chi-square and logistic regression (adjusting for patient characteristics that were unbalanced between the two groups) to determine associations between the two groups and 6-month outcomes. Results: Within six months of an initial visit for an SRD, a statistically significantly smaller proportion of PSC patients utilized healthcare resources for spine care as compared to the PC patients. When adjusting for patient characteristics, those who received care from the PSC clinician were less likely within 6 months of an initial visit to be hospitalized (OR =.47, 95% CI.23–.97), fill a prescription for an opioid analgesic (OR =.43; 95% CI.29–.65), receive a spinal injection (OR =.56, 95% CI.33–.95), or have a visit with a specialist (OR =.48, 95% CI.35–.67) as compared to those who received usual primary care. Conclusions: Patients who received PSC in an academic primary care clinic experienced significantly less escalation of their spine care within 6 months of their initial visit. The PSC model may offer a more efficient approach to the primary care of spine problems for patients with SRDs, as compared to usual primary care
Initial efficacy of MI, TTM tailoring and HRI’s with multiple behaviors for employee health promotion
Objective: This study was designed to compare the initial efficacy of Motivational Interviewing (MI), Online Transtheoretical Model (TTM)-tailored communications and a brief Health Risk Intervention (HRI) on four health risk factors (inactivity, BMI, stress and smoking) in a worksite sample.
Method: A randomized clinical trial assigned employees to one of three recruitment strategies and one of the three treatments. The treatment protocol included an HRI session for everyone and in addition either a recommended three TTM online sessions or three MI in person or telephone sessions over 6 months. At the initial post-treatment assessment at 6 months, groups were compared on the percentage who had progressed from at risk to taking effective action on each of the four risks.
Results: Compared to the HRI only group, the MI and TTM groups had significantly more participants in the Action stage for exercise and effective stress management and significantly fewer risk behaviors at 6 months. MI and TTM group outcomes were not different.
Conclusion: This was the first study to demonstrate that MI and online TTM could produce significant multiple behavior changes. Future research will examine the long-term impacts of each treatment, their cost effectiveness, effects on productivity and quality of life and process variables mediating outcomes
Remote Sensing of Chiral Signatures on Mars
We describe circular polarization as a remote sensing diagnostic of chiral
signatures which may be applied to Mars. The remarkable phenomenon of
homochirality provides a unique biosignature which can be amenable to remote
sensing through circular polarization spectroscopy. The natural tendency of
microbes to congregate in close knit communities would be beneficial for such a
survey. Observations of selected areas of the Mars surface could reveal chiral
signatures and hence explore the possibility of extant or preserved biological
material. We describe a new instrumental technique that may enable observations
of this form.Comment: 14 pages, 3 figures; to be published in Planetary and Space Scienc
Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat
Superoxide is the proximal reactive oxygen species (ROS) produced by the mitochondrial respiratory chain and plays a major role in pathological oxidative stress and redox signaling. While there are tools to detect or decrease mitochondrial superoxide, none can rapidly and specifically increase superoxide production within the mitochondrial matrix. This lack impedes progress, making it challenging to assess accurately the roles of mitochondrial superoxide in cells and in vivo. To address this unmet need, we synthesized and characterized a mitochondria-targeted redox cycler, MitoParaquat (MitoPQ) that comprises a triphenylphosphonium lipophilic cation conjugated to the redox cycler paraquat. MitoPQ accumulates selectively in the mitochondrial matrix driven by the membrane potential. Within the matrix, MitoPQ produces superoxide by redox cycling at the flavin site of complex I, selectively increasing superoxide production within mitochondria. MitoPQ increased mitochondrial superoxide in isolated mitochondria and cells in culture ~a thousand-fold more effectively than untargeted paraquat. MitoPQ was also more toxic than paraquat in the isolated perfused heart and in Drosophila in vivo. MitoPQ enables the selective generation of superoxide within mitochondria and is a useful tool to investigate the many roles of mitochondrial superoxide in pathology and redox signaling in cells and in vivo
Life in Hot Carbon Monoxide: The Complete Genome Sequence of Carboxydothermus hydrogenoformans Z-2901
We report here the sequencing and analysis of the genome of the thermophilic bacterium Carboxydothermus hydrogenoformans Z-2901. This species is a model for studies of hydrogenogens, which are diverse bacteria and archaea that grow anaerobically utilizing carbon monoxide (CO) as their sole carbon source and water as an electron acceptor, producing carbon dioxide and hydrogen as waste products. Organisms that make use of CO do so through carbon monoxide dehydrogenase complexes. Remarkably, analysis of the genome of C. hydrogenoformans reveals the presence of at least five highly differentiated anaerobic carbon monoxide dehydrogenase complexes, which may in part explain how this species is able to grow so much more rapidly on CO than many other species. Analysis of the genome also has provided many general insights into the metabolism of this organism which should make it easier to use it as a source of biologically produced hydrogen gas. One surprising finding is the presence of many genes previously found only in sporulating species in the Firmicutes Phylum. Although this species is also a Firmicutes, it was not known to sporulate previously. Here we show that it does sporulate and because it is missing many of the genes involved in sporulation in other species, this organism may serve as a “minimal” model for sporulation studies. In addition, using phylogenetic profile analysis, we have identified many uncharacterized gene families found in all known sporulating Firmicutes, but not in any non-sporulating bacteria, including a sigma factor not known to be involved in sporulation previously
Control of mitochondrial superoxide production by reverse electron transport at complex I.
The generation of mitochondrial superoxide (O2̇̄) by reverse electron transport (RET) at complex I causes oxidative damage in pathologies such as ischemia reperfusion injury, but also provides the precursor to H2O2 production in physiological mitochondrial redox signaling. Here, we quantified the factors that determine mitochondrial O2̇̄ production by RET in isolated heart mitochondria. Measuring mitochondrial H2O2 production at a range of proton-motive force (Δp) values and for several coenzyme Q (CoQ) and NADH pool redox states obtained with the uncoupler p-trifluoromethoxyphenylhydrazone, we show that O2̇̄ production by RET responds to changes in O2 concentration, the magnitude of Δp, and the redox states of the CoQ and NADH pools. Moreover, we determined how expressing the alternative oxidase from the tunicate Ciona intestinalis to oxidize the CoQ pool affected RET-mediated O2̇̄ production at complex I, underscoring the importance of the CoQ pool for mitochondrial O2̇̄ production by RET. An analysis of O2̇̄ production at complex I as a function of the thermodynamic forces driving RET at complex I revealed that many molecules that affect mitochondrial reactive oxygen species production do so by altering the overall thermodynamic driving forces of RET, rather than by directly acting on complex I. These findings clarify the factors controlling RET-mediated mitochondrial O2̇̄ production in both pathological and physiological conditions. We conclude that O2̇̄ production by RET is highly responsive to small changes in Δp and the CoQ redox state, indicating that complex I RET represents a major mode of mitochondrial redox signaling
The Influence of Literacy on Patient-Reported Experiences of Diabetes Self-Management Support
Variability in disease-related outcomes may relate to how patients experience self-management support in clinical settings
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