2,596 research outputs found
The Yo-Yo IE2 Test: Physiological Response for Untrained Men versus Trained Soccer Players
PURPOSE: To examine the physical capacity and physiological response to the Yo-Yo Intermittent Endurance level 2 test (IE2) for untrained individuals and trained male soccer players, and to investigate the determinants of intense intermittent exercise performance. METHODS: Thirty-four healthy untrained males (UTR) and fifteen age-matched trained soccer players (TR) performed a maximal incremental treadmill test (ITT) and a Yo-Yo IE2 test. Muscle biopsies and blood samples were obtained and HR were measured before, during and after tests. RESULTS: UTR had a 67% lower (P95%HRmax was lower (P0.05). CONCLUSION: The Yo-Yo IE2 test was shown to possess high construct validity by showing large differences in performance, heart rates and anaerobic metabolism between untrained individuals and trained soccer players. Additionally, VO2max appeared to be important for intermittent exercise performance in untrained individuals, but not for trained soccer players
Recreational soccer is an effective health-promoting activity for untrained men
Copyright BMJ publishing GroupTo examine the effects of regular participation in recreational soccer on health profile, 36 healthy untrained Danish men aged 20-43 years were randomised into a soccer group (SO; n=13), a running group (RU; n=12) and a control group (CO; n=11). Training was performed for 1 h two or three times per week for 12 weeks; at an average heart rate of 82% (SEM 2%) and 82% (1%) of HRmax for SO and RU, respectively. During the 12 week period, maximal oxygen uptake increased (p < 0.05) by 13% (3%) and 8% (3%) in SO and RU, respectively. In SO, systolic and diastolic blood pressure were reduced (p < 0.05) from 130 (2) to 122 (2) mm Hg and from 77 (2) to 72 (2) mm Hg, respectively, after 12 weeks, with similar decreases observed for RU. After the 12 weeks of training, fat mass was 3.0% (2.7 (0.6) kg) and 1.8% (1.8 (0.4) kg) lower (p < 0.05) for SO and RU, respectively. Only SO had an increase in lean body mass (1.7 (0.4) kg, p < 0.05), an increase in lower extremity bone mass (41 (8) g, p < 0.05), a decrease in LDL-cholesterol (2.7 (0.2) to 2.3 (0.2) mmol/l; p < 0.05) and an increase (p < 0.05) in fat oxidation during running at 9.5 km/h. The number of capillaries per muscle fibre was 23% (4%) and 16% (7%) higher (p < 0.05) in SO and RU, respectively, after 12 weeks. No changes in any of the measured variables were observed for CO. In conclusion, participation in regular recreational soccer training, organised as small-sided drills, has significant beneficial effects on health profile and physical capacity for untrained men, and in some aspects it is superior to frequent moderate-intensity running
Emotional valence, sense of agency and responsibility: A study using intentional binding
We investigated how the emotional valence of an action outcome influences the experience of control, in an intentional binding experiment. Voluntary actions were followed by emotionally positive or negative human vocalisations, or by neutral tones. We used mental chronometry to measure a retrospective component of sense of agency (SoA), triggered by the occurrence of the action outcome, and a prospective component, driven by the expectation that the outcome will occur. Positive outcomes enhanced the retrospective component of SoA, but only when both occurrence and the valence of the outcome were unexpected. When the valence of outcomes was blocked - and therefore predictable - we found a prospective component of SoA when neutral tones were expected but did not actually occur. This prospective binding was absent, and reversed, for positive and negative expected outcomes. Emotional expectation counteracts the prospective component of SoA, suggesting a distancing effect
Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory
This article is meant as a summary and introduction to the ideas of effective
field theory as applied to gravitational systems.
Contents:
1. Introduction
2. Effective Field Theories
3. Low-Energy Quantum Gravity
4. Explicit Quantum Calculations
5. ConclusionsComment: 56 pages, 2 figures, JHEP style, Invited review to appear in Living
Reviews of Relativit
Better assessment of physical function: item improvement is neglected but essential
INTRODUCTION: Physical function is a key component of patient-reported outcome (PRO) assessment in rheumatology. Modern psychometric methods, such as Item Response Theory (IRT) and Computerized Adaptive Testing, can materially improve measurement precision at the item level. We present the qualitative and quantitative item-evaluation process for developing the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank.
METHODS: The process was stepwise: we searched extensively to identify extant Physical Function items and then classified and selectively reduced the item pool. We evaluated retained items for content, clarity, relevance and comprehension, reading level, and translation ease by experts and patient surveys, focus groups, and cognitive interviews. We then assessed items by using classic test theory and IRT, used confirmatory factor analyses to estimate item parameters, and graded response modeling for parameter estimation. We retained the 20 Legacy (original) Health Assessment Questionnaire Disability Index (HAQ-DI) and the 10 SF-36\u27s PF-10 items for comparison. Subjects were from rheumatoid arthritis, osteoarthritis, and healthy aging cohorts (n = 1,100) and a national Internet sample of 21,133 subjects.
RESULTS: We identified 1,860 items. After qualitative and quantitative evaluation, 124 newly developed PROMIS items composed the PROMIS item bank, which included revised Legacy items with good fit that met IRT model assumptions. Results showed that the clearest and best-understood items were simple, in the present tense, and straightforward. Basic tasks (like dressing) were more relevant and important versus complex ones (like dancing). Revised HAQ-DI and PF-10 items with five response options had higher item-information content than did comparable original Legacy items with fewer response options. IRT analyses showed that the Physical Function domain satisfied general criteria for unidimensionality with one-, two-, three-, and four-factor models having comparable model fits. Correlations between factors in the test data sets were \u3e 0.90.
CONCLUSIONS: Item improvement must underlie attempts to improve outcome assessment. The clear, personally important and relevant, ability-framed items in the PROMIS Physical Function item bank perform well in PRO assessment. They will benefit from further study and application in a wider variety of rheumatic diseases in diverse clinical groups, including those at the extremes of physical functioning, and in different administration modes
Hepatitis C prevalence in Denmark in 2016âAn updated estimate using multiple national registers
Background: Chronic hepatitis C (CHC) can be eliminated as a public health threat by meeting the WHO targets: 90% of patients diagnosed and 80% treated by 2030. To achieve and monitor progress towards elimination, an updated estimate of the size of the CHC population is needed, but Denmark has no complete national CHC register. By combining existing registers in 2007, we estimated the population living with CHC to be 16,888 (0.38% of the adult population).
Aim: To estimate the population living with diagnosed and undiagnosed CHC in Denmark on 31 December 2016. Among additional aims were to estimate the proportion of patients attending specialised clinical care.
Methods: People with diagnosed CHC were identified from four national registers. The total diagnosed population was estimated by capture-recapture analysis. The undiagnosed population was estimated by comparing the register data with data from two cross-sectional surveys.
Results: The population living with diagnosed CHC in Denmark was 7,581 persons (95%CI: 7,416â12,661) of which 6,116 (81%) were identified in the four registers. The estimated undiagnosed fraction was 24%, so the total CHC infected population was 9,975 corresponding to 0.21% of the adult population (95%CI: 9,758â16,659; 0.21%-0.36%). Only 48% of diagnosed patients had received specialised clinical care.
Conclusion: CHC prevalence in Denmark is declining and 76% of patients have been diagnosed. Linking diagnosed patients to care and increasing efforts to test people with former or current drug use will be necessary to achieve CHC elimination
Encephalomeningocele cases over 10 years in Thailand: a case series
BACKGROUND: Encephalomeningocele, especially in the frontoethmoidal region, is a form of neural tube defect which affects patients in Southeast Asia more commonly than in Western countries. Its underlying cause is not known but teratogenic environmental agents are suspected. However, nutritional deficiency, as in spina bifida, cannot be excluded. METHODS: This study reports 21 cases of meningocele (without brain tissue in the lesion) and encephalomeningocele (with brain tissue) that were admitted to our hospital for surgical corrections in the period of ten years, from 1990 to 1999. Clinicopathological findings, as well as occupations of family members and prenatal exposures to infectious agents or chemicals were reviewed and analyzed. RESULTS: The most commonly involved area was the frontoethmoidal region, found in 20 cases. The combined pattern between nasoethmoidal and nasoorbital defects was found most frequently (11 from 21 cases) and had more associated abnormalities. Encephalomeningocele had more related abnormalities than meningocele with proportions of 0.6 and 0.3, respectively. CONCLUSIONS: Here, we confirmed that genetic defects are not likely to be the single primary cause of this malformation. However, we could not draw any conclusions on etiologic agents. We suggest that case control studies and further investigation on the role of nutritional deficiencies, especially folic acid, in the pathogenesis of encephalomeningocele are necessary to clarify the underlying mechanisms
Signatures of Star-planet interactions
Planets interact with their host stars through gravity, radiation and
magnetic fields, and for those giant planets that orbit their stars within
10 stellar radii (0.1 AU for a sun-like star), star-planet
interactions (SPI) are observable with a wide variety of photometric,
spectroscopic and spectropolarimetric studies. At such close distances, the
planet orbits within the sub-alfv\'enic radius of the star in which the
transfer of energy and angular momentum between the two bodies is particularly
efficient. The magnetic interactions appear as enhanced stellar activity
modulated by the planet as it orbits the star rather than only by stellar
rotation. These SPI effects are informative for the study of the internal
dynamics and atmospheric evolution of exoplanets. The nature of magnetic SPI is
modeled to be strongly affected by both the stellar and planetary magnetic
fields, possibly influencing the magnetic activity of both, as well as
affecting the irradiation and even the migration of the planet and rotational
evolution of the star. As phase-resolved observational techniques are applied
to a large statistical sample of hot Jupiter systems, extensions to other
tightly orbiting stellar systems, such as smaller planets close to M dwarfs
become possible. In these systems, star-planet separations of tens of stellar
radii begin to coincide with the radiative habitable zone where planetary
magnetic fields are likely a necessary condition for surface habitability.Comment: Accepted for publication in the handbook of exoplanet
Perturbative quantum gravity with the Immirzi parameter
We study perturbative quantum gravity in the first-order tetrad formalism.
The lowest order action corresponds to Einstein-Cartan plus a parity-odd term,
and is known in the literature as the Holst action. The coupling constant of
the parity-odd term can be identified with the Immirzi parameter of loop
quantum gravity. We compute the quantum effective action in the one-loop
expansion. As in the metric second-order formulation, we find that in the case
of pure gravity the theory is on-shell finite, and the running of Newton's
constant and the Immirzi parameter is inessential. In the presence of fermions,
the situation changes in two fundamental aspects. First, non-renormalizable
logarithmic divergences appear, as usual. Second, the Immirzi parameter becomes
a priori observable, and we find that it is renormalized by a four-fermion
interaction generated by radiative corrections. We compute its beta function
and discuss possible implications. The sign of the beta function depends on
whether the Immirzi parameter is larger or smaller than one in absolute value,
and the values plus or minus one are UV fixed-points (we work in Euclidean
signature). Finally, we find that the Holst action is stable with respect to
radiative corrections in the case of minimal coupling, up to higher order
non-renormalizable interactions.Comment: v2 minor amendment
Distinguishing Various Models of the 125 GeV Boson in Vector Boson Fusion
The hint of a new particle around 125 GeV at the LHC through the decay modes
of diphoton and a number of others may point to quite a number of
possibilities. While at the LHC the dominant production mechanism for the Higgs
boson of the standard model and some other extensions is via the gluon fusion
process, the alternative vector boson fusion is more sensitive to electroweak
symmetry breaking through the gauge-Higgs couplings and therefore can be used
to probe for models beyond the standard model. In this work, using the well
known dijet-tagging technique to single out the vector boson fusion mechanism,
we investigate its capability to discriminate a number of models that have been
suggested to give an enhanced inclusive diphoton production rate, including the
standard model Higgs boson, fermiophobic Higgs boson, Randall-Sundrum radion,
inert-Higgs-doublet model, two-Higgs-doublet model, and the MSSM. The rates in
vector-boson fusion can give more information of the underlying models to help
distinguishing among the models.Comment: 31 pages, 3 figures; in this version some wordings are change
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