383 research outputs found
One-repetition-maximum measures or maximum bar-power output: which Is more related to sport performance?
Purpose: This study compared the associations between optimum power loads and 1-repetition maximum (1RM) values (assessed in half-squat [HS] and jump squat [JS] exercises) and multiple performance measures in elite athletes.
Methods: Sixty-one elite athletes (fifteen Olympians) from four different sports (track and field [sprinters and jumpers], rugby sevens, bobsled, and soccer) performed squat and countermovement jumps, HS exercise (for assessing 1RM), HS and JS exercises (for assessing bar-power output), and sprint tests (60-m for sprinters and jumpers and 40-m for the other athletes). Pearson’s product moment correlation test was used to determine relationships between 1RM and bar-power outputs with vertical jumps and sprint times in both exercises.
Results: Overall, both measurements were moderately to near perfectly related to speed performance (r values varying from -0.35 to -0.69 for correlations between 1RM and sprint times, and from -0.36 to -0.91 for correlations between bar-power outputs and sprint times; P< 0.05). However, on average, the magnitude of these correlations was stronger for power-related variables, and only the bar-power outputs were significantly related to vertical jump height.
Conclusions: The bar-power outputs were more strongly associated with sprint-speed and power performance than the 1RM measures. Therefore, coaches and researchers can use the bar-power approach for athlete testing and monitoring. Due to the strong correlations presented, it is possible to infer that meaningful variations in bar-power production may also represent substantial changes in actual sport performance
Mjerenje radona u vodi radi predviđanja potresa u Sloveniji
Radon (222Rn) concentration in water of several thermal springs was measured with the aim of obtaining a correlation with the seismic activity of the region. Though a qualitative correlation was found for a spring with deep water circulation, we are far from being able to predict either the time or the place of an earthquake. An additional study with more relevant sampling sites and more frequent water analyses would be necessary to achieve this.Mjerili smo količinu radona (222Rn) u vodi iz više izvora radi utvrđivanja moguće korelacije sa seizmičkom aktivnosti u Sloveniji. Iako smo našli kvalitativnu korelaciju za jedan izvor s dubokim kruženjem vode, nismo još u mogućnosti predvidjeti mjesto ili vrijeme potresa. Za to su potrebna proširena mjerenja na više mjesta i sa češćim uzorkovanjem vode
Personality Traits in Miners with Past Occupational Elemental Mercury Exposure
In this study, we evaluated the impact of long-term occupational exposure to elemental mercury vapor (Hg(0)) on the personality traits of ex-mercury miners. Study groups included 53 ex-miners previously exposed to Hg(0) and 53 age-matched controls. Miners and controls completed the self-reporting Eysenck Personality Questionnaire and the Emotional States Questionnaire. The relationship between the indices of past occupational exposure and the observed personality traits was evaluated using Pearson’s correlation coefficient and on a subgroup level by machine learning methods (regression trees). The ex-mercury miners were intermittently exposed to Hg(0) for a period of 7–31 years. The means of exposure-cycle urine mercury (U-Hg) concentrations ranged from 20 to 120 μg/L. The results obtained indicate that ex-miners tend to be more introverted and sincere, more depressive, more rigid in expressing their emotions and are likely to have more negative self-concepts than controls, but no correlations were found with the indices of past occupational exposure. Despite certain limitations, results obtained by the regression tree suggest that higher alcohol consumption per se and long-term intermittent, moderate exposure to Hg(0) (exposure cycle mean U-Hg concentrations > 38.7 < 53.5 μg/L) in interaction with alcohol remain a plausible explanation for the depression associated with negative self-concept found in subgroups of ex-mercury miners. This could be one of the reason for the higher risk of suicide among miners of the Idrija Mercury Mine in the last 45 years
Primary debulking surgery versus primary neoadjuvant chemotherapy for high grade advanced stage ovarian cancer: Comparison of survivals
The aim of the study was to analyze the overall survival (OS) and progression free survival (PFS) of patients with high grade and advanced stage epithelial ovarian cancer (EOC) with at least 60 months of follow-up treated in a single gynecologic oncology institute. We compared primary debulking surgery (PDS) versus neoadjuvant chemotherapy plus interval debulking surgery (NACT + IDS) stratifying data based on residual disease with the intent to identify the rationale for therapeutic option decision and the role of laparoscopic evaluation of resectability for that intention. This is observational retrospective study on consecutive patients with diagnosis of high grade and International Federation of Gynecology and Obstetrics (FIGO) stage III/IV EOC referred to our center between January 2008 and May 2012. We selected only patients with a follow-up of at least 60 months. Primary endpoint was to compare PDS versus NACT + IDS in term of progression free survival (PFS) and overall survival (OS). Secondary endpoints were PFS and OS stratifying data according to residual disease after surgery in patients receiving PDS versus NACT + IDS. Finally, through Cox hazards models, we tested the prognostic value of different variables (patient age at diagnosis, residual disease after debulking, American Society of Anesthesiologists (ASA) stage, number of adjuvant-chemotherapy cycles) for predicting OS. A total number of 157 patients were included in data analysis. Comparing PDS arm (108 patients) and NACT + IDS arm (49 patients) we found no significant differences in term of OS (41.3 versus 34.5 months, respectively) and PFS (17.3 versus 18.3 months, respectively). According to residual disease we found no significant differences in term of OS between NACT + IDS patients with residual disease = 0 and PDS patients with residual disease = 0 or residual disease = 1, as well as no significant differences in PFS were found comparing NACT + IDS patients with residual disease = 0 and PDS patients with residual disease = 0; contrarily, median PFS resulted significantly lower in PDS patients receiving optimal debulking (residual disease = 1) in comparison to NACT + IDS patients receiving complete debulking (residual disease = 0). PDS arm was affected by a significant higher rate of severe post-operative complications (grade 3 and 4). Diagnostic laparoscopy before surgery was significantly associated with complete debulking. We confirm previous findings concerning the non-superiority of NACT + IDS compared to PDS for the treatment of EOC, even if NACT + IDS treatment was associated with significant lower rate of post-operative complications. On the other hand, selecting patients for NACT + IDS, based on laparoscopic evaluation of resectabilty prolongs the PFS and does not worse the OS compared to the patients not completely debulked with PDS
Olfactory and trigeminal interaction of menthol and nicotine in humans
The purpose of the study was to investigate the interactions between two stimuli—menthol and nicotine—both of which activate the olfactory and the trigeminal system. More specifically, we wanted to know whether menthol at different concentrations modulates the perception of burning and stinging pain induced by nicotine stimuli in the human nose. The study followed an eightfold randomized, double-blind, cross-over design including 20 participants. Thirty phasic nicotine stimuli at one of the two concentrations (99 and 134 ng/mL) were applied during the entire experiment every 1.5 min for 1 s; tonic menthol stimulation at one of the three concentrations (0.8, 1.5 and 3.4 μg/mL) or no-menthol (placebo control conditions) was introduced after the 15th nicotine stimulus. The perceived intensities of nicotine’s burning and stinging pain sensations, as well as perceived intensities of menthol’s odor, cooling and pain sensations, were estimated using visual analog scales. Recorded estimates of stinging and burning sensations induced by nicotine initially decreased (first half of the experiment) probably due to adaptation/habituation. Tonic menthol stimulation did not change steady-state nicotine pain intensity estimates, neither for burning nor for stinging pain. Menthol-induced odor and cooling sensations were concentration dependent when combined with low-intensity nicotine stimuli. Surprisingly, this dose dependency was eliminated when combining menthol stimuli with high-intensity nicotine stimuli. There was no such nicotine effect on menthol’s pain sensation. In summary, we detected interactions caused by nicotine on menthol perception for odor and cooling but no effect was elicited by menthol on nicotine pain sensation
Simulation of Ultra-High Energy Photon Propagation in the Geomagnetic Field
The identification of primary photons or specifying stringent limits on the
photon flux is of major importance for understanding the origin of ultra-high
energy (UHE) cosmic rays. We present a new Monte Carlo program allowing
detailed studies of conversion and cascading of UHE photons in the geomagnetic
field. The program named PRESHOWER can be used both as an independent tool or
together with a shower simulation code. With the stand-alone version of the
code it is possible to investigate various properties of the particle cascade
induced by UHE photons interacting in the Earth's magnetic field before
entering the Earth's atmosphere. Combining this program with an extensive air
shower simulation code such as CORSIKA offers the possibility of investigating
signatures of photon-initiated showers. In particular, features can be studied
that help to discern such showers from the ones induced by hadrons. As an
illustration, calculations for the conditions of the southern part of the
Pierre Auger Observatory are presented.Comment: 41 pages, 9 figures, added references in introduction, corrected
energy in row 1 of Table 3, extended caption of Table
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