1,697 research outputs found

    Hopanoids Play a Role in Membrane Integrity and pH Homeostasis in Rhodopseudomonas palustris TIE-1

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    Sedimentary hopanes are pentacyclic triterpenoids that serve as biomarker proxies for bacteria and certain bacterial metabolisms, such as oxygenic photosynthesis and aerobic methanotrophy. Their parent molecules, the bacteriohopanepolyols (BHPs), have been hypothesized to be the bacterial equivalent of sterols. However, the actual function of BHPs in bacterial cells is poorly understood. Here, we report the physiological study of a mutant in Rhodopseudomonas palustris TIE-1 that is unable to produce any hopanoids. The deletion of the gene encoding the squalene-hopene cyclase protein (Shc), which cyclizes squalene to the basic hopene structure, resulted in a strain that no longer produced any polycyclic triterpenoids. This strain was able to grow chemoheterotrophically, photoheterotrophically, and photoautotrophically, demonstrating that hopanoids are not required for growth under normal conditions. A severe growth defect, as well as significant morphological damage, was observed when cells were grown under acidic and alkaline conditions. Although minimal changes in shc transcript expression were observed under certain conditions of pH shock, the total amount of hopanoid production was unaffected; however, the abundance of methylated hopanoids significantly increased. This suggests that hopanoids may play an indirect role in pH homeostasis, with certain hopanoid derivatives being of particular importance

    Relationship of Cigarette Consumption and Upper Respiratory Disease among College Students

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    Higher Educatio

    Preliminary Results of Magnetic Gradiometry and Photogrammetric Imagery from La Playa, Sonora, Mexico (SON F:10:3)

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    Covering an area of nearly ten square kilometers, La Playa (SON F:10:3) is one of the most important archaeological sites in northwest Mexico. While La Playa has been best known for its Early Agricultural occupation, this research, funded through National Geographic, targets the poorly understood origins of the Trincheras Tradition. This poster presents initial results of magnetic gradiometry and photogrammetric imagery collected from the site in April 2017 as part of the ongoing binational project Proyecto La Playa. Along with magnetic gradiometry data collection, several unmanned aerial vehicle flights with a Trimble UX5 captured photogrammetric images of the site. This data has yielded the possible presence of irrigation canals, pithouses, and thermal features. With erosion damaging much of La Playa, this research documents at-risk features for future excavation

    A Randomized Trial of Realignment Therapy for Treatment of Medial Tibiofemoral Osteoarthritis

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    Objectives: The objective of this 30-week randomized crossover trial was to determine whether a multi-modal realignment therapy would be successful in relieving pain and improving function among persons with medial tibiofemoral OA. METHODS: We conducted a double blind, randomized crossover trial of a multi-modal realignment therapy for persons with medial tibiofemoral OA. Trial participants met ACR criteria for OA with knee pain, aching or stiffness on most days of the past month and radiographic evidence of a definite osteophyte with predominant medial tibiofemoral OA. We tested two different treatments: A) CONTROL TREATMENT consisting of a neutral knee brace (no valgus angulation), flat unsupportive foot orthoses, and shoes with a flexible midsole; and B) ACTIVE TREATMENT consisting of a valgus knee brace, customized neutral foot orthoses, and shoes designed for motion control. For each subject, the trial lasted 30 weeks, including 12 weeks each of active and control treatment separated by a 6-week washout period. The primary outcome of the linear regression model was change in knee pain and function as assessed by the WOMAC Osteoarthritis Index. RESULTS: 80 participants with medial tibiofemoral OA were randomized. Their mean age was 62 years, mean BMI was 34 kg/m2 and mean WOMAC pain score was 9.2 (0-20 scale). There was no evidence of a carryover effect. The regression model demonstrated that the mean difference in pain between the active and control treatments was -1.82 units (95% confidence interval: -3.05 to -0.60 [p=0.004]) on the WOMAC pain scale, indicating a small, but statistically significant decrease in pain with the multi-modal active treatment. For WOMAC function the realignment intervention had a non-significant effect on function with a -2.90 unit decrease (95% CI -6.60 to 0.79) compared with the control condition (p=0.12). CONCLUSION: Multi-modal realignment therapy decreases pain in persons with medial tibiofemoral OA

    Walking with lions: why there is no role for captive-origin lions Panthera leo in species restoration

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    Despite formidable challenges and few successes in reintroducing large cats from captivity to the wild, the release of captives has widespread support from the general public and local governments, and continues to occur ad hoc. Commercial so-called lion Panthera leo encounter operations in Africa exemplify the issue, in which the captive breeding of the lion is linked to claims of reintroduction and broader conservation outcomes. In this article we assess the capacity of such programmes to contribute to in situ lion conservation. By highlighting the availability of wild founders, the unsuitability of captive lions for release and the evidence-based success of wild-wild lion translocations, we show that captive-origin lions have no role in species restoration. We also argue that approaches to reintroduction exemplified by the lion encounter industry do not address the reasons for the decline of lions in situ, nor do they represent a model that can be widely applied to restoration of threatened felids elsewher

    Self-Reported Low Vitality, Poor Mental Health, and Low Dietary Restraint Are Associated with Overperception of Physical Exertion

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    Objective. We investigated whether perceived exertion, in comparison to the physiological response to exercise, was associated with self-reported vitality, mental health, and physical function during daily activities, or weight control behaviors. Design. Weight-reduced, formerly overweight women (n = 126, aged 22–46 years), completed health and dietary control questionnaires, and underwent a treadmill-walking task while heart rate, ventilation, respiratory exchange ratio, and ratings of perceived exertion were recorded. Results. Overperception of exertion (perceived exertion physiological exertion) was inversely associated with vitality (r = −0.190, P < .05), mental health (r = −0.188, P < .05), and dietary control (r values range −0.231 to −0.317, P < .05). In linear regression modeling, vitality or mental health, and cognitive dietary restraint were independently associated with accuracy of perceived exertion, independent of age, ethnicity, and engagement in exercise during weight loss. Each model explained 7%-8% of the variance in accuracy of perceived exertion. Conclusion. Women with low vitality or poor mental health, and poor dietary control may overperceive exertion. Such overperception may be a barrier to engage in physical activity and thus increase susceptibility to weight gain

    Lived Experiences of American Adults who Survive COVID-19: Implications for Physical Activity and Interpersonal Stress

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    Introduction: The cumulative number of COVID-19 cases has surpassed 579 million globally. Symptoms during and after COVID-19 infection vary from mild cold symptoms to severe multisystem illness. Given the wide range of symptom presentations and complications post COVID-19, the purpose of this study was to describe the lived experience of American adults surviving COVID-19. Method: This study employed an exploratory qualitative description design. Semi-structured interviews were conducted with a sample of 35 individuals, [white (94%), female (71%), mean age = 43.7 years], with proximity to a university in an urban Midwest American city. Interviews occurred between May and August 2021, three or more months after participants tested positive for COVID-19. Results: Forty percent of the 35 participants experienced prolonged COVID-19 symptoms impacting their lifestyle. Four themes characterized the impacts of the post COVID-19 condition on the lives of the participants within the context of a global pandemic: (a) disruptions in health & well-being, (b) persistent uncertainty, (c) disruptions in interpersonal relationships, (d) beneficent outcomes and adaptation. Discussion: This study of COVID-19 has identified important implications for physical activity and interpersonal stress. Prolonged COVID-19 symptoms led to disruptions in the health, well-being, and interpersonal relationships of participants. Healthcare professionals need to attend to symptoms post COVID-19, assess interpersonal functioning, and provide guidance on physical activity. Future studies are recommended to track consequences of COVID-19’s impact on long-term health and well-being

    Different scenarios for Candida parapsilosis fungaemia reveal high numbers of mixed C-parapsilosis and Candida orthopsilosis infections

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    Nosocomial fungal bloodstream infections (BSI) are increasing significantly in hospitalized patients and Candida parapsilosis has emerged as an important pathogen responsible for numerous outbreaks. The objective of this study was to evaluate C. parapsilosis sensu lato infection scenarios, regarding species distribution and strain relatedness. One hundred isolates of C. parapsilosis sensu lato derived from blood cultures and catheter tips were analysed by multiplex microsatellite typing and by sequencing D1/D2 regions of the ribosomal DNA. Our results indicate that 9.5 % of patients presented infections due to C. parapsilosis and Candida orthopsilosis, 57.1 % due to C. parapsilosis, 28.3 % due to C. orthopsilosis and 4.8% due to Candida metapsilosis. Eighty per cent of the C. parapsilosis BSIs were due to a single strain that was also identified in the catheter, but in 10% of the cases C. parasilosis was identified in the catheter but the BSI was due to C. orthopsilosis. There is a significant probability that C. parapsilosis isolates collected from the same patient at more than 3 months interval are of different strains (P=0.0179). Moreover, several isolates were identified persistently in the same hospital, infecting six different patients. The incidence of polyfungal BSI infections with C. parapsilosis and C. orthopsilosis is reported herein for the first time, emphasizing the fact that the species identified in the catheter is not always responsible for the BSI, thus impacting the treatment strategy. The observation that strains can remain in the hospital environment for years highlights the possible existence of reservoirs and reinforces the need for accurate genotyping tools, such as the markers used for elucidating epidemiological associations and detecting outbreaks.Financial support was provided by CAPES Foundation (BEX 19194/12-9), Ministry of Education of Brazil, Brasilia (DF 70.040-020), by FEDER through POFC-COMPETE and by Portuguese funds from FCT (PEst-OE/BIA/UI4050/2014). R.M.Z.-O. is supported in part by CNPq (350338/2000-0) and FAPERJ E (26/103.157/2011). We are grateful to Ronaldo Rozembaun from HSE and SAM and Andrea Pussenti Derossi from HUPE for providing the Candida isolates and technical assistance in sampling. Automated sequencing was done using the genomic platform/DNA sequencing platform at Fundacao Oswaldo Cruz, PDTIS/FIOCRUZ (RPT01A), Brazil. The authors declare that they have no conflict of interest.info:eu-repo/semantics/publishedVersio

    Isolation of bacterial extrachromosomal DNA from human dental plaque associated with periodontal disease,using transposonaided capture (TRACA)

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    The human oral cavity is host to a complex microbial community estimated to comprise > 700 bacterial species, of which at least half are thought to be not yet cultivable in vitro. To investigate the plasmids present in this community, we used a transposon-aided capture system, which allowed the isolation of plasmids from human oral supra- and subgingival plaque samples. Thirty-two novel plasmids and a circular molecule that could be an integrase-generated circular intermediate were isolated
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