829 research outputs found

    The friction of saline ice on aluminium

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    The friction of ice on other materials controls loading on offshore structures and vessels in the Arctic. However, ice friction is complicated, because ice in nature exists near to its melting point. Frictional heating can cause local softening, and perhaps melting and lubrication, thus affecting the friction and creating a feedback loop. Ice friction is therefore likely to depend on sliding speed and sliding history, as well as bulk temperature. The roughness of the sliding materials may also affect the friction. Here we present results of a series of laboratory experiments, sliding saline ice on aluminium, and controlling for roughness and temperature. We find that the friction of saline ice on aluminium, Ī¼ice-al = 0.1 typically, but that this value varies with sliding conditions. We propose physical models which explain the variations in sliding friction

    Can exhaled volatile organic compounds differentiate high and low responders to resistance exercise?

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    Participation in resistance training improves muscle strength and size, as well as reduced risk of chronic disease and frailty. However, the exercise response to resistance training is highly variable. In part this may be attributed to individual physiological differences. Identification of biomarkers that can distinguish between high and low responders to exercise are therefore of interest. Exhaled volatile organic compounds may provide a non-invasive method of monitoring the physiological response to resistance training. However, the relationship between exhaled organic compounds and the acute response to resistance exercise is not fully understood. Therefore, this research will investigate exhaled volatile organic compounds in acute response to resistance exercise with an aim to discover a common group of compounds that can predict high and low responders to standardised resistance training. Ā© 2022 Elsevier Lt

    Correspondence between geometrical and differential definitions of the sine and cosine functions and connection with kinematics

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    In classical physics, the familiar sine and cosine functions appear in two forms: (1) geometrical, in the treatment of vectors such as forces and velocities, and (2) differential, as solutions of oscillation and wave equations. These two forms correspond to two different definitions of trigonometric functions, one geometrical using right triangles and unit circles, and the other employing differential equations. Although the two definitions must be equivalent, this equivalence is not demonstrated in textbooks. In this manuscript, the equivalence between the geometrical and the differential definition is presented assuming no a priori knowledge of the properties of sine and cosine functions. We start with the usual length projections on the unit circle and use elementary geometry and elementary calculus to arrive to harmonic differential equations. This more general and abstract treatment not only reveals the equivalence of the two definitions but also provides an instructive perspective on circular and harmonic motion as studied in kinematics. This exercise can help develop an appreciation of abstract thinking in physics.Comment: 6 pages including 1 figur

    The Assessment of Hydration Status and Renal Markers Associated with Acute Kidney Injury in NCAA Division I Female Soccer Players During Preseason Training in South Texas: A Pilot Study

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    Recent research suggest that recurrent heat-associated dehydration and strenuous physical exertion may be associated with the development of acute and potentially chronic renal dysfunction. Typical South Texas environmental conditions in August, during preseason, on NCAA female college athletes may warrant concerns for promoting acute kidney injury (AKI). PURPOSE: The purpose of this study is to investigate hydration status and renal biomarkers in NCAA Division I female soccer athletes in South Texas during the preseason. METHODS: (Mean Ā± SEM; n = 12; age: 19.5 Ā± 0.9 y; ht: 167.6 Ā± 6.24 cm; wt: 66.6 Ā± 10.15 kg). Each subject participated in Pre-and post-body composition measures via DXA (iDXA, Lunar Prodigy), pre-, post-practice, and game weight changes (SECA Model 769); provided 14-urine samples throughout the preseason for hydration via Urine Specific Gravity (USG) and renal function Creatinine (UCr) ELISA analyses. Urine samples were collected prior to preseason (PRE-PS), fitness testing days (FT1, FT2), regular practices (MidW1, MidW2, POST-PS) and exhibition games (PRE-BU, POST-BU,12HR-BU, 24HR-BU, PRE-UT, POST-UT, 12HR-UT, 24HR-UT). Heat index was assessed at each practice session and exhibition match (Kestrel 5000; Kestrel Meters). RESULTS: 1-way ANOVA for USG analysis, a difference was found at MidW2 prior to the end of the POST-PS 1.018 Ā± .001 (p = .03; CI: 1.017-1.025) and early fitness testing values (FT1: 1.022 Ā± 0.005; FT2: 1.022 Ā± 0.006) and the MidW1 of the pre-season 1.025 Ā±.001; (p = .004; CI: 1.022 - 1.027). The BU game USG pre-measure was lower than post (POST-BU, 12 h and 24 h) \u3c p = .02; 1.01 Ā± .001; CI: 1.008 - 1.016), a difference was found during the UT game pre-measure compared to POST-UT and 12 h post values 1.009 Ā± .0016 (p = .0009; CI: 1.006 - 1.013) and no different than the 24 h POST-UT 1.014 Ā± .001. 2-way ANOVA ( x heat index x time) for UCr (mgĀ· dL-1Ā· LBM-1), a difference was found between PRE-BU and POST-BU (p = .001; CI: .448 - 3.81) and comparing PRE-UT to POST-UT (p = \u3c .0001; CI: 2.57 - 6.31) and 12HR-UT (p = \u3c .0001; CI: 2.09 - 5.21). CONCLUSION: Our current analysis suggests, the subjects were euhydrated prior to the exhibition games and hypohydrated 12-hours post-exhibition game, prior to fitness assessments (FT1, FT2), and regular morning practice (MidW1). UCr increased above normative values post-exhibition games. The increases in UCr may be independent of hydration status and muscle mass as euhydration was maintained post-exhibition matches

    Interview with Half Century Club Inductees, Class of 1930

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    Oral history interview with Illinois State Normal University alumni, Class of 1930. The interview was conducted on May 10, 1980, by an unidentified interviewer. They discuss President Felmley, influential faculty, and racial discrimination experienced by students of color.https://ir.library.illinoisstate.edu/aoh/1002/thumbnail.jp

    A simple algorithm to assess patient suitability for Calypso-seed implantation for four-dimensional prostate localization

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    Purpose: To retrospectively determine the proportion of prostate cancer patients who are appropriate candidates for prostate localization with Calypso (Calypso Medical, Seattle, WA); to assess the accuracy of surface-anatomy in predicting prostate depth; and, to describe a simple clinical-algorithm predicting patientā€™s appropriateness for Calypso localization. Methods: Medical records and archived CT scans of all patients treated for localized prostate cancer at our institution between 2006 and 2007 were reviewed. Association between the feasibility of Calypso use, the depth of the prostate from the anterior torso, and a variety of anatomic factors were assessed (ANOVA, linear regression, and ROC). Results: Patients were appropriate for the Calypso system in 91% of cases (localize and track, 52%; localize only, 39%). Strong correlation between greater trochanter location and the posterior prostate was seen (r 2 =0.91, mean difference 0.6 cm). The negative predictive value of the greater trochanter measurements was 31%. 31/45 patients (69%) who were deemed inappropriate for Calypso based on greater trochanter to anterior torso measurements were eligible on the basis of CT-based measurements of prostate depth. Weight, BMI, waist circumference, and hip circumference) correlated with distance from the prostate to the anterior torso and were predictive of Calypso appropriateness. All patients with weight ?100 kg, BMI ?30, or waist/hip circumference ?100cm, were eligible for Calypso. Conclusions: Most prostate cancer patients are candidates for Calypso localization +/- tracking. The greater trochanter to anterior torso distance underestimates the number of eligible patients. Weight, BMI and waist/hip circumference are good predictors for Calypso appropriateness

    Experiments with Data Mining in Enterprise Management

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    Abstract This paper describes experiments in applying data mining techniques to historical data collected by network monitoring agents. Large amounts of performance data, including network, system, and application performance data, are collected and stored by monitoring agents. Data mining algorithms analyze the data and codify it into usable knowledge. We show, via experiments, that the knowledge contains useful and unexpected suggestions for improving the effectiveness of business processes and for reducing management support effort. Four experiments are discussed: three preliminary lab experiments and one large, real-world experiment at a major airline company

    Benefits of supportive strategies for carers of people with high-grade glioma: a systematic review: Strategies for addressing the needs of high-grade glioma carers

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    Purpose: To systematically review and examine current evidence for the carer-reported benefits of supportive care strategies for carers of adults with high-grade glioma (HGG). Methods: Four databases (CINAHL, EMBASE, PubMed, PsycINFO) were searched for articles published between January 2005 and April 2022 that assessed strategies for addressing the supportive care needs of carers of adults with HGG (WHO grade 3ā€“4). Study selection and critical appraisal were conducted independently by three authors (DJ/MC, 2021; DJ/RJ 2022). Data extraction was conducted by one author (DJ) and checked by a second author (RJ). Results were synthesised narratively. Results: Twenty-one studies involving 1377 caregivers were included, targeting the carer directly (n = 10), the patient-carer dyad (n = 3), or focused on people with HGG + / āˆ’ their carers (n = 8). A paucity of high-quality evidence exists for effective and comprehensive support directly addressing outcomes for carers of adults with HGG. Strategies that demonstrated some benefits included those that built carer knowledge or provided emotional support, delivered by health professionals or through peer support. Supportive and early palliative care programmes have potential to reduce unmet carer needs while providing ongoing carer support. Conclusion: Strategies incorporating an educational component, emotional support, and a regular needs assessment with corresponding tailored support are most valued by carers. Future practice development research should adopt a value-based approach and exceed evaluation of efficacy outcomes to incorporate evaluation of the experience of patients, carers, and staff, as well as costs
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