Sub-Synchronous Vibration on Centrifugal Compressor with Tilt-Pad Bearings

Case StudyThis presentation provides a success story that sub- synchronous vibration was eliminated on a centrifugal compressor. The sub-synchronous vibration originally occurred at high operational speed on this 5-stage hydrogen recycle centrifugal compressor supported by tilt-pad bearings. Vibration data is reviewed to find its root-cause. Each possible malfunction is discussed to see if it was likely the root-cause. It is shown that sub-synchronous vibration not caused by surge or stall could still happen even with tilt-pad bearings. A solution was implemented to successfully resolve the issue

Sex differences in time perception during self-paced running

International Journal of Exercise Science 9(4): 514-523, 2016. Time perception during exercise may be affected by chosen intensity, and may also affect enjoyment of exercise and subsequent long-term adherence. However, little is known about how individuals perceive the passage of time during exercise, or if factors such as sex are influential. The purpose of this study was to determine if there are sex related differences in perception of time during a bout of exercise in experienced runners. Twenty-two recreational runners (11 men, 11 women) participated in a bout of treadmill running where they were allowed to select their intensity. Sixty second prospective time estimations were taken before, during (at 33%, 66% and 90% of the completed distance), and after the run. Heart rate (HR) was also recorded throughout. The women (M = 91.9, SD = 3.3) ran at a significantly higher percentage of their maximum HR than the men (M = 86.5, SD = 6.4; p = 0.022), choosing to run at a higher relative intensity than the men when given the opportunity to self-pace. The women had relatively lower time estimations overall, showing that they perceived time to be passing by more slowly compared to the men. These results may help to explain sex related differences in exercise adherence

Neuromuscular Adaptations in Elderly Adults Are Task-Specific during Stepping and Obstacle Clearance Tasks.

Elderly adults have a diminished movement capacity due to physiological and neurological declines associated with advancing age. Previous research suggests that elderly adults use altered neuromuscular patterns to conduct activities of daily living (ADLs). Limited research has addressed these altered activation strategies in obstacle clearance, stair ascent and stair descent. The purpose of this study was to compare neuromuscular activation patterns in young and elderly adults during these tasks. Eleven young and 10 healthy elderly adults performed five downward stepping, upward stepping and obstacle clearance trials. Surface EMG was measured from the quadriceps, hamstrings, gastrocnemius and tibialis anterior muscles. A 2x3 (group x condition) repeated measures analysis of variance was used to determine significant differences in muscle activation intensity. An apriori alpha level was set at p\u3c0.05. The results showed that elderly adults exhibited greater activation intensity than the young adults in all movement conditions. The significant differences in muscle activation intensity in the elderly adults were limited to the musculature driving the tested movement. The findings of the current study support previous research that elderly adults perform ADLs at a greater relative intensity than young adults. Furthermore, the current study shows that the disproportionate increase in muscle activation intensity is limited to the muscles that functionally drive the required task

The costs and benefits of active case management and rehabilitation for musculoskeletal disorders

The burden of musculoskeletal disorders (MSDs) to employers and workplaces is significant; and the most important cost to employers and society is lost time from work. ‘Case management’ is a goal-oriented approach to keeping employees at work and facilitating an early return to work. There is good scientific evidence that case management methods are costeffective through reducing time off work and lost productivity, and reducing healthcare costs. There is even stronger evidence that best-practice rehabilitation approaches have the very important potential to significantly reduce the burden of long-term sickness absence due to MSDs. The combination of case management with suitable rehabilitation principles is currently being used effectively in multiple settings throughout the UK, and there is growth within the case management sector. Current providers vary widely in quality and experience. There is limited professional regulation, although localised standards of practice have recently become available. Many of the factors influencing the adoption of cost-effective case management and rehabilitation approaches rest with employers, and funders/commissioners of healthcare. It may be easier to integrate these practices into large and medium-sized workplaces, but there is no reason why the same principles cannot be applied to small businesses and the self-employed. It appears to be very timely for the distribution of information to employers and other key players about how effective case management and suitable rehabilitation approaches can be, and how applicable they are to UK settings. To this end, an integrated model specific to the UK has been developed. An evidence-based model for managing those with MSDs was developed that is widely applicable to all types of industry and business in the UK. It describes the principles to apply in order to integrate case management and rehabilitation with the workplace. It was derived from high quality scientific studies, and research conducted into views on the applicability and effectiveness within the UK. It is recommended that HSE distribute guidance based on this model

LOCATE: a mammalian protein subcellular localization database

LOCATE is a curated, web-accessible database that houses data describing the membrane organization and subcellular localization of mouse and human proteins. Over the past 2 years, the data in LOCATE have grown substantially. The database now contains high-quality localization data for 20% of the mouse proteome and general localization annotation for nearly 36% of the mouse proteome. The proteome annotated in LOCATE is from the RIKEN FANTOM Consortium Isoform Protein Sequence sets which contains 58 128 mouse and 64 637 human protein isoforms. Other additions include computational subcellular localization predictions, automated computational classification of experimental localization image data, prediction of protein sorting signals and third party submission of literature data. Collectively, this database provides localization proteome for individual subcellular compartments that will underpin future systematic investigations of these regions. It is available at http://locate.imb.uq.edu.au

Warming and elevated CO2 promote rapid incorporation and degradation of plant-derived organic matter in an ombrotrophic peatland

Rising temperatures have the potential to directly affect carbon cycling in peatlands by enhancing organic matter (OM) decomposition, contributing to the release of CO2 and CH4 to the atmosphere. In turn, increasing atmospheric CO2 concentration may stimulate photosynthesis, potentially increasing plant litter inputs belowground and transferring carbon from the atmosphere into terrestrial ecosystems. Key questions remain about the magnitude and rate of these interacting and opposing environmental change drivers. Here, we assess the incorporation and degradation of plant- and microbe-derived OM in an ombrotrophic peatland after 4 years of whole-ecosystem warming (+0, +2.25, +4.5, +6.75 and +9°C) and two years of elevated CO2 manipulation (500 ppm above ambient). We show that OM molecular composition was substantially altered in the aerobic acrotelm, highlighting the sensitivity of acrotelm carbon to rising temperatures and atmospheric CO2 concentration. While warming accelerated OM decomposition under ambient CO2, new carbon incorporation into peat increased in warming × elevated CO2 treatments for both plant- and microbe-derived OM. Using the isotopic signature of the applied CO2 enrichment as a label for recently photosynthesized OM, our data demonstrate that new plant inputs have been rapidly incorporated into peat carbon. Our results suggest that under current hydrological conditions, rising temperatures and atmospheric CO2 levels will likely offset each other in boreal peatlands

Hyponatremia in Severe Malaria: Evidence for an Appropriate Anti-diuretic Hormone Response to Hypovolemia

Although hyponatremia occurs in most patients with severe malaria, its pathogenesis, prognostic significance, and optimal management have not been established. Clinical and biochemical data were prospectively collected from 171 consecutive Bangladeshi adults with severe malaria. On admission, 57% of patients were hyponatremic. Plasma sodium and Glasgow Coma Score were inversely related (rs = −0.36, P < 0.0001). Plasma antidiuretic hormone concentrations were similar in hyponatremic and normonatremic patients (median, range: 6.1, 2.3–85.3 versus 32.7, 3.0–56.4 pmol/L; P = 0.19). Mortality was lower in hyponatremic than normonatremic patients (31.6% versus 51.4%; odds ratio [95% confidence interval]: 0.44 [0.23–0.82]; P = 0.01 by univariate analysis). Plasma sodium normalized with crystalloid rehydration from (median, range) 127 (123–140) mmol/L on admission to 136 (128–149) mmol/L at 24 hours (P = 0.01). Hyponatremia in adults with severe malaria is common and associated with preserved consciousness and decreased mortality. It likely reflects continued oral hypotonic fluid intake in the setting of hypovolemia and requires no therapy beyond rehydration

The clinical implications of thrombocytopenia in adults with severe falciparum malaria: a retrospective analysis

BackgroundThrombocytopenia is a common finding in adults with severe falciparum malaria, but its clinical and prognostic utility is incompletely defined.MethodsClinical and laboratory data from 647 adults with severe falciparum malaria were analysed retrospectively to determine the relationship between a patient&rsquo;s platelet count on admission to hospital and their subsequent clinical course.ResultsOn admission, 614 patients (94.9%) were thrombocytopenic (platelet count &lt;150&thinsp;&times;&thinsp;109/L) and 328 (50.7%) had a platelet count &lt;50&thinsp;&times;&thinsp;109/L. The admission platelet count was inversely correlated with parasite biomass (estimated from plasma PfHRP2 concentrations, rs&thinsp;=&thinsp;&minus;0.28, P&thinsp;=&thinsp;0.003), the degree of microvascular sequestration (measured with orthogonal polarizing spectral imaging, rs&thinsp;=&thinsp;&minus;0.31, P&thinsp;=&thinsp;0.001) and disease severity (the number of World Health Organization severity criteria satisfied by the patient, rs&thinsp;=&thinsp;&minus;0.21, P &lt;0.001). Platelet counts were lower on admission in the patients who died (median: 30 (interquartile range 22 to 52)&thinsp;&times;&thinsp;109/L versus 50 (34 to 78)&thinsp;&times;&thinsp;109/L in survivors; P &lt;0.001), but did not predict outcome independently from other established laboratory and clinical prognostic indices. The 39 patients (6%) with profound thrombocytopenia (platelet count &lt;20&thinsp;&times;&thinsp;109/L) were more likely to die (odds ratio: 5.00, 95% confidence interval: 2.56 to 9.75) than patients with higher platelet counts, but these high-risk patients could be identified more rapidly with simple bedside clinical assessment. The admission platelet count did not reliably identify the 50 patients (7.7%) with major bleeding during the study.ConclusionsThrombocytopenia is a marker of disease severity in adults with falciparum malaria, but has limited utility in prognostication, triage and management