476 research outputs found

    An experimental examination of low-energy cosmic ray heavy nuclei

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    Low energy cosmic ray heavy nuclei examination by sounding rocke

    Cognitive mediation in people with dementia:Development, structural, and construct validity of the first dementia‐specific measure

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    OBJECTIVES: Anxiety and depression are common and deleterious comorbidities in people living with dementia (PLWD). Cognitive behavioural therapy (CBT) is one of the few promising treatments; however, it is unclear whether PLWD have the necessary prerequisites to engage in this. Having an understanding of cognitive mediation, that a thought mediates the relationship between an antecedent event and its emotional consequence, is key for engaging with CBT and is also a critical component of emotion regulation. There are no measures of this construct validated for PLWD. This study aims to adapt and validate an existing measure for this population. A secondary aim is to assess its applicability in older adults (OA) without a recognised neurocognitive impairment. // METHODS: A measure of cognitive mediation was adapted via expert and service user consultation for use in PLWD. A total of 102 PLWD and 77 OA without neurocognitive impairments completed the adapted measure along with two measures of emotion recognition and reasoning. Factor structure was examined separately in both samples, and the measure reduced, with convergent validity assessed. // RESULTS: A final measure of 10 items (named the CM-Dem) was subject to factor analysis yielding a single factor solution. The measure showed good psychometric properties in PLWD, including good model fit, high internal consistency, inter-rater reliability, and moderate convergent validity with related constructs. In contrast, poor validity was found in OA, especially a lack of convergent validity. // CONCLUSIONS: The CM-Dem has clinical and research utility as a measure of cognitive mediation in PLWD, but less so in OA

    Mutant Alcohol Dehydrogenase Leads to Improved Ethanol Tolerance in Clostridium Thermocellum

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    Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. Biochemical assays confirm a complete loss of NADH-dependent activity with concomitant acquisition of NADPH-dependent activity, which likely affects electron flow in the mutant. The simplicity of the genetic basis for the ethanol-tolerant phenotype observed here informs rational engineering of mutant microbial strains for cellulosic ethanol production

    Structure of the sporulation histidine kinase inhibitor Sda from Bacillus subtilis and insights into its solution state

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    The crystal structure of the DNA-damage checkpoint inhibitor of sporulation, Sda, from Bacillus subtilis, has been solved by the MAD technique using selenomethionine-substituted protein. The structure closely resembles that previously solved by NMR, as well as the structure of a homologue from Geobacillus stearothermophilus solved in complex with the histidine kinase KinB. The structure contains three molecules in the asymmetric unit. The unusual trimeric arrangement, which lacks simple internal symmetry, appears to be preserved in solution based on an essentially ideal fit to previously acquired scattering data for Sda in solution. This interpretation contradicts previous findings that Sda was monomeric or dimeric in solution. This study demonstrates the difficulties that can be associated with the characterization of small proteins and the value of combining multiple biophysical techniques. It also emphasizes the importance of understanding the physical principles behind these techniques and therefore their limitations

    Functional Heterologous Expression of an Engineered Full Length Cipa from Clostridium Thermocellum in Thermoanaerobacterium Saccharolyticum

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    Background: Cellulose is highly recalcitrant and thus requires a specialized suite of enzymes to solubilize it into fermentable sugars. In C. thermocellum, these extracellular enzymes are present as a highly active multi-component system known as the cellulosome. This study explores the expression of a critical C. thermocellum cellulosomal component in T. saccharolyticum as a step toward creating a thermophilic bacterium capable of consolidated bioprocessing by employing heterologously expressed cellulosomes. Results:We developed an inducible promoter system based on the native T. saccharolyticum xynA promoter, which was shown to be induced by xylan and xylose. The promoter was used to express the cellulosomal component cipA*, an engineered form of the wild-type cipAfrom C. thermocellum. Expression and localization to the supernatant were both verified for CipA*. When a ΔcipA mutant C. thermocellum strain was cultured with a CipA*-expressing T. saccharolyticum strain, hydrolysis and fermentation of 10 grams per liter SigmaCell 101, a highly crystalline cellulose, were observed. This trans-species complementation of a cipA deletion demonstrated the ability for CipA* to assemble a functional cellulosome. Conclusion: This study is the first example of an engineered thermophile heterologously expressing a structural component of a cellulosome. To achieve this goal we developed and tested an inducible promoter for controlled expression in T. saccharolyticum as well as a synthetic cipA . In addition, we demonstrate a high degree of hydrolysis (up to 93%) on microcrystalline cellulose

    Electrosurgical bipolar vessel sealing for a standing flank ovariectomy in beef heifers

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    Traditional ovariectomy techniques for heifers (e.g. colpotomy) have adverse effects ranging from hemorrhage to mortality. Electrosurgical bipolar vessel sealing devices offer a superior ligation of ovarian pedicle and associated structures. In ruminants, standing flank laparotomy has been used for abdominal visibility. We performed ovariectomy in 2 companion beef heifers via a unilateral flank approach, combined with electrosurgical ligation. Surgeries were performed in standing animals, under local anesthesia, with no observed short- or long-term adverse effects. This technique is worth considering for cases where the security of electrosurgical ligation combined with the accessibility of a flank laparotomy are desired. Additional research is needed to determine the viability of the technique for cattle of various ages and breeds

    Validation of PROMIS physical function for evaluating outcome after acute Achilles tendon rupture

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    Background: There is increased demand for valid, reliable, and responsive patient-reported outcome measures (PROMs) to evaluate treatment for Achilles tendon rupture, but not all PROMs currently in use are reliable and responsive for this condition. Purpose: To evaluate the measurement properties of the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) compared with other PROMs used after treatment for acute Achilles tendon rupture. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A retrospective cohort study with a follow-up questionnaire was performed. All adult patients with an acute Achilles tendon rupture between June 2016 and June 2018 with a minimum 12-month follow-up were eligible for inclusion. Functional outcome was assessed using the PROMIS PF computerized adaptive test (CAT), Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL), FAAM-Sports, and Achilles Tendon Total Rupture Score (ATRS). Pearson correlation (r) was used to assess the correlations between PROMs. Absolute and relative floor and ceiling effects were calculated. Results: In total, 103 patients were included (mean age, 44.7 years; 74% male); 82 patients (79.6%) underwent operative repair, while 21 patients (20.4%) underwent nonoperative management. The mean time between treatment and collection of PROMs was 25.3 months (range, 15-36 months). The mean scores were 55.4 +/- 9.2 (PROMIS PF), 92.9 +/- 12.2 (FAAM-ADL), 77.7 +/- 22.9 (FAAM-Sports), and 83.0 +/- 19.4 (ATRS). The ATRS was correlated with FAAM-ADL (r = 0.80; 95% CI, 0.72-0.86; P < .001) and FAAM-Sports (r = 0.86; 95% CI, 0.80-0.90; P < .001). The PROMIS PF was correlated with the FAAM-ADL (r = 0.66; 95% CI, 0.53-0.75; P < .001), FAAM-Sports (r = 0.65; 95% CI, 0.53-0.75; P < .001), and ATRS (r = 0.69; 95% CI, 0.58-0.78; P < .001). The PROMIS PF did not show absolute floor or ceiling effects (0%). The FAAM-ADL (35.9%), FAAM-Sports (15.8%), and ATRS (20.4%) had substantial absolute ceiling effects. Conclusion: The PROMIS PF, FAAM-ADL, and FAAM-Sports all showed a moderate to high mutual correlation with the ATRS. Only the PROMIS PF avoided substantial floor and ceiling effects. The results suggest that the PROMIS PF CAT is a valid, reliable, and perhaps the most responsive tool to evaluate patient outcomes after treatment for an Achilles tendon rupture.Clinical epidemiolog
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