217 research outputs found
Practical Implementation of Machine tool Metrology and Maintenance Management Systems
Maximising asset utilisation and minimising downtime and waste are becoming increasingly important to all manufacturing facilities as competition increases and profits decrease. The tools to assist with monitoring these machining processes are becoming more and more in demand. A system designed to fulfil the needs of machine tool operators and supervisors has been developed and its impact on the precision manufacturing industry is being considered. The benefits of implementing this system, compared to traditional methods, will be discussed here
Seasonal and spatial variation in the stable isotopic composition (δ18O and δD) of precipitation in south Florida
Precipitation data collected from five sites in south Florida indicate a strong seasonal and spatial variation in δ18O and δD, despite the relatively limited geographic coverage and low-lying elevation of each of the collection sites. Based upon the weighted-mean stable isotope values, the sites were classified as coastal Atlantic, inland, and lower Florida Keys. The coastal Atlantic sites had weighted-mean values of δ18O and δD of â2.86â° and â12.8â°, respectively, and exhibited a seasonal variation with lower δ18O and δD values in the summer wet-season precipitation (δ18O = â3.38â°, δD = â16.5â°) as compared to the winter-time precipitation (δ18O = â1.66â°, δD = â3.2â°). The inland site was characterized as having the highest d-excess value (+13.3â°), signifying a contribution of evaporated Everglades surface water to the local atmospheric moisture. In spite of its lower latitude, the lower Keys site located at Long Key had the lowest weighted-mean stable isotope values (δ18O = â3.64â°, δD = â20.2â°) as well as the lowest d-excess value of (+8.8â°). The lower δD and δ18O values observed at the Long Key site reflect the combined effects of oceanic vapor source, fractionation due to local precipitation, and slower equilibration of the larger raindrops nucleated by a maritime aerosol. Very low δ18O and δD values (δ18O \u3c â6â°, δD \u3c â40â°) were observed just prior to the passage of hurricanes from the Gulf of Mexico as well as during cold fronts from the north-west. These results suggest that an oceanic vapor source region to the west, may be responsible for the extremely low δD and δ18O values observed during some tropical storms and cold fronts
The effects of mindfulness-based cognitive therapy on affective memory recall dynamics in depression:A mechanistic model of rumination
Objectives: converging research suggests that mindfulness training exerts its therapeutic effects on depression by reducing rumination. Theoretically, rumination is a multifaceted construct that aggregates multiple neurocognitive aspects of depression, including poor executive control, negative and overgeneral memory bias, and persistence or stickiness of negative mind states. Current measures of rumination, most-often self-reports, do not capture these different aspects of ruminative tendencies, and therefore are limited in providing detailed information about the mechanisms of mindfulness. Methods: we developed new insight into the potential mechanisms of rumination, based on three model-based metrics of free recall dynamics. These three measures reflect the patterns of memory retrieval of valenced information: the probability of first recall (Pstart) which represents initial affective bias, the probability of staying with the same valence category rather than switching, which indicates strength of positive or negative association networks (Pstay), and probability of stopping (Pstop) or ending recall within a given valence, which indicates persistence or stickiness of a mind state. We investigated the effects of Mindfulness-Based Cognitive Therapy (MBCT; Nâ=â29) vs. wait-list control (Nâ=â23) on these recall dynamics in a randomized controlled trial in individuals with recurrent depression. Participants completed a standard laboratory stressor, the Trier Social Stress Test, to induce negative mood and activate ruminative tendencies. Following that, participants completed a free recall task consisting of three word lists. This assessment was conducted both before and after treatment or wait-list. Results: while MBCT participantâs Pstart remained relatively stable, controls showed multiple indications of depression-related deterioration toward more negative and less positive bias. Following the intervention, MBCT participants decreased in their tendency to sustain trains of negative words and increased their tendency to sustain trains of positive words. Conversely, controls showed the opposite tendency: controls stayed in trains of negative words for longer, and stayed in trains of positive words for less time relative to pre-intervention scores. MBCT participants tended to stop recall less often with negative words, which indicates less persistence or stickiness of negatively valenced mental context. Conclusion: MBCT participants showed a decrease in patterns that may perpetuate rumination on all three types of recall dynamics (Pstart, Pstay, and Pstop), compared to controls. MBCT may weaken the strength of self-perpetuating negative associations networks that are responsible for the persistent and âstickyâ negative mind states observed in depression, and increase the positive associations that are lacking in depression. This study also offers a novel, objective method of measuring several indices of ruminative tendencies indicative of the underlying mechanisms of rumination
Molecular Techniques Reveal Wide Phyletic Diversity of Heterotrophic Microbes Associated with Discodermia spp. (Porifera: Demospongiae)
Sponges are well known to harbor large numbers of heterotrophic microbes within their mesohyl. Studies to determine the diversity of these associated microbes have been attempted for only a few shallow water species. We cultured various microorganisms from several species of Discodermia collected from deep water using the \u27Johnson-Sea-Link\u27 manned submersibles, and characterised them by standard microbiological identification methods. Characterisation of a small proportion (ca. 10%) of the total and potential eubacterial isolate collection with molecular systematics techniques revealed a wide diversity of microbes. Phylogenetic analyses of 32 small subunit (SSU) 16S-like rRNA gene sequences from different micorbes indicated high levels of taxonomic diversity assoiated with this genus of sponge. For example, bacteria from at least five cubacterial subdivisions - gamma, alpha, beta, Cytophaga and Gram positive - were isolated from the mesohyl of Discodermia. Several strains were unidentifiable from current sequence databases. No overlap was found between sequences of 24 isolates and 8 sequences obtained by PCR and cloning directly from sponge samples. The abundance and diversity of microbes associated with sponges such as Discodermia suggest that they may play important roles in marine microbial ecology, dispersal and evolution
Respiratory sinus arrhythmia and heart period in infancy as correlates of later oppositional defiant and callous-unemotional behaviors
Extant literature suggests that oppositional defiant (ODD) and callous-unemotional (CU) behaviors in childhood and adolescence are associated with distinct patterns of psychophysiological functioning and that individual differences in these patterns have implications for developmental pathways to disorder. Very little is known about the associations between psychophysiological functioning in infancy and later ODD and CU behaviors. This study examined associations between basal autonomic nervous system (ANS) functioning in infancy and ODD and CU behaviors in later childhood. Using longitudinal heart period (HP) and respiratory sinus arrhythmia (RSA) data from the Durham Child Health and Development Study (N = 206), the current study tested associations, within a structural equation modeling framework, between continuous measures of HP and RSA across the first two years of life and later ODD and CU behaviors at first grade. Results indicate that ODD and CU behaviors in childhood are associated with lower baseline RSA, but not HP, across infancy. The implications of these findings for developmental models of ODD and CU behaviors are discussed
Severe osteomyelitis caused by Myceliophthora thermophila after a pitchfork injury
BACKGROUND: Traumatic injuries occurring in agricultural settings are often associated with infections caused by unusual organisms. Such agents may be difficult to isolate, identify, and treat effectively. CASE REPORT: A 4-year-old boy developed an extensive infection of his knee and distal femur following a barnyard pitchfork injury. Ultimately the primary infecting agent was determined to be Myceliophthora thermophila, a thermophilic melanized hyphomycete, rarely associated with human infection, found in animal excreta. Because of resistance to standard antifungal agents including amphotericin B and caspofungin, therapy was instituted with a prolonged course of terbinafine and voriconazole. Voriconazole blood levels demonstrated that the patient required a drug dosage (13.4 mg/kg) several fold greater than that recommended for adults in order to attain therapeutic blood levels. CONCLUSION: Unusual pathogens should be sought following traumatic farm injuries. Pharmacokinetic studies may be of critical importance when utilizing antifungal therapy with agents for which little information exists regarding drug metabolism in children
Effect of Pre-Exercise Nutrition on Human Skeletal Muscle UCP3 Expression
BACKGROUND: Increased UCP3 expression in skeletal muscle after exercise may be attributed to elevated free fatty acids (FFA) that are known to directly activate UCP3 expression. Pre-exercise glucose consumption has shown to blunt UCP3 expression in response to exercise. Since glucose ingestion before and during exercise is typically not a common practice, the goal of the present study was to assess the effect of a multi-macronutrient meal (drinkable shake) in the pre-exercise period towards human skeletal muscle UCP3 expression. METHODS: Using a crossover design, untrained participants performed an endurance exercise session (350 kcal at 70% of their VO2max) after two experimental conditions 1) consumption of a multi-macronutrient meal and 2) a fasting period of 8 h. Blood samples were taken at baseline, pre-exercise, post-exercise, 1h, and 4h post-exercise, while muscle biopsies were taken at the last four time points. RESULTS: A significant increase in FFA was observed in the fasting condition (p= 0.046) as well as a significant increase in UCP3 mRNA and protein expression at post-exercise (p= 0.042) and 4 h post-exercise (p= 0.036) respectively, in the multi-macronutrient meal condition. DISCUSSION: Variables showed a total opposite response to what has been reported after the consumption of pure glucose before an exercise session. Instead of observing a decrease in UCP3 expression in the non-fasting condition, we observed a significant increase in UCP3 mRNA and protein concentration in the multi-macronutrient condition. According to previous research, variables such as the protein and fat content from the multi-macronutrient meal, as well as the insulin levels, could have played key roles in altering UCP3 mRNA and protein expression in the multi-macronutrient condition; however, further research is needed to confirm this hypothesis. CONCLUSION: The expression of UCP3 mRNA and protein expression as a result of exercise might be controlled by factors other than FFA
Nitrite circumvents platelet resistance to nitric oxide in patients with heart failure preserved ejection fraction and chronic atrial fibrillation
Aims: Heart failure (HF) is a pro-thrombotic state. Both platelet and vascular responses to nitric oxide (NO) donors are impaired in HF patients with reduced ejection fraction (HFrEF) compared to healthy volunteers (HV) due to scavenging of NO, and possibly also reduced activity of the principal NO sensor, soluble guanylate cyclase (sGC), limiting the therapeutic potential of NO donors as anti-aggregatory agents. Previous studies have shown that nitrite inhibits platelet activation presumptively after its reduction to NO, but the mechanism(s) involved remain poorly characterized. Our aim was to compare the effects of nitrite on platelet function in HV vs. HF patients with preserved ejection fraction (HFpEF) and chronic atrial fibrillation (HFpEF-AF), vs. patients with chronic AF without HF, and to assess whether these effects occur independent of the interaction with other formed elements of blood. Methods and Results: Platelet responses to nitrite and the NO donor sodium nitroprusside (SNP) were compared in age-matched HV controls (nâ=â12), HFpEF-AF patients (nâ=â29) and chronic AF patients (nâ=â8). Anti-aggregatory effects of nitrite in the presence of NO scavengers/sGC inhibitor were determined and vasodilator-stimulated phosphoprotein (VASP) phosphorylation was assessed using Western blotting. In HV and chronic AF, both nitrite and SNP inhibited platelet aggregation in a concentration-dependent manner. Inhibition of platelet aggregation by the NO donor SNP was impaired in HFpEF-AF patients compared to healthy and chronic AF individuals, but there was no impairment of the anti-aggregatory effects of nitrite. Nitrite circumvented platelet NO resistance independently of other blood cells by directly activating sGC and phosphorylating VASP. Conclusion: We here show for the first time that HFpEF-AF (but not chronic AF without HF) is associated with marked impairment of platelet NO responses due to sGC dysfunction and nitrite circumvents the âplatelet NO resistanceâ phenomenon in human HFpEF, at least partly, by acting as a direct sGC activator independent of NO
Introduction of a Novel Swine-Origin Influenza A (H1N1) Virus into Milwaukee, Wisconsin in 2009
On 17 April 2009, novel swine origin influenza A virus (S-OIV) cases appeared within the United States. Most influenza A diagnostic assays currently utilized in local clinical laboratories do not allow definitive subtype determination. Detailed subtype analysis of influenza A positive samples in our laboratory allowed early confirmation of a large outbreak of S-OIV in southeastern Wisconsin (SEW). The initial case of S-OIV in SEW was detected on 28 April 2009. All influenza A samples obtained during the 16 week period prior to 28 April 2009, and the first four weeks of the subsequent epidemic were sub typed. Four different multiplex assays were employed, utilizing real time PCR and end point PCR to fully subtype human and animal influenza viral components. Specific detection of S-OIV was developed within days. Data regarding patient demographics and other concurrently circulating viruses were analyzed. During the first four weeks of the epidemic, 679 of 3726 (18.2%) adults and children tested for influenza A were identified with S-OIV infection. Thirteen patients (0.34%) tested positive for seasonal human subtypes of influenza A during the first two weeks and none in the subsequent 2 weeks of the epidemic. Parainfluenza viruses were the most prevalent seasonal viral agents circulating during the epidemic (of those tested), with detection rates of 12% followed by influenza B and RSV at 1.9% and 0.9% respectively. S-OIV was confirmed on day 2 of instituting subtype testing and within 4 days of report of national cases of S-OIV. Novel surge capacity diagnostic infrastructure exists in many specialty and research laboratories around the world. The capacity for broader influenza A sub typing at the local laboratory level allows timely and accurate detection of novel strains as they emerge in the community, despite the presence of other circulating viruses producing identical illness. This is likely to become increasingly important given the need for appropriate subtype driven anti-viral therapy and the potential shortage of such medications in a large epidemic
Vitamin D did not reduce multiple sclerosis disease activity after a clinically isolated syndrome
Low serum levels of 25-hydroxyvitamin D (25(OH)D), and low sunlight exposure, are known risk factors for the development of multiple sclerosis. Add-on vitamin D supplementation trials in established multiple sclerosis have been inconclusive. The effects of vitamin D supplementation to prevent multiple sclerosis is unknown. We aimed to test the hypothesis that oral vitamin D3 supplementation in high-risk clinically isolated syndrome (abnormal MRI, at least three T2 brain and/or spinal cord lesions), delays time to conversion to definite multiple sclerosis, that the therapeutic effect is dose-dependent, and that all doses are safe and well tolerated. We conducted a double-blind trial in Australia and New Zealand. Eligible participants were randomised 1:1:1:1 to placebo, 1000, 5000, or 10 000 IU of oral vitamin D3 daily within each study centre (n=23) and followed for up to 48 weeks. Between 2013 and 2021, we enrolled 204 participants. Brain MRI scans were performed at baseline, 24 and 48 weeks. The main study outcome was conversion to clinically definite multiple sclerosis based on the 2010 McDonald criteria defined as either a clinical relapse or new brain MRI T2 lesion development. We included 199 cases in the intention-to-treat analysis based on assigned dose. Of these, 116 converted to multiple sclerosis by 48 weeks (58%). Compared to placebo, the HRs (95%CI) for conversion were 1000 IU 0.87 (0.50, 1.50); 5000 IU 1.37 (0.82, 2.29); and 10 000 IU 1.28 (0.76, 2.14). In an adjusted model including age, sex, latitude, study centre, and baseline symptom number, clinically isolated syndrome onset site, presence of infratentorial lesions, and use of steroids, the HRs (versus placebo) were 1000 IU 0.80 (0.45, 1.44); 5000 IU 1.36 (0.78, 2.38); 10 000 IU 1.07 (0.62, 1.85). Vitamin D3 supplementation was safe and well tolerated. We did not demonstrate reduction in multiple sclerosis disease activity by vitamin D3 supplementation after a high-risk clinically isolated syndrome. Trial registration Australian Clinical Trials Registration Number ACTRN12612001160820
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