Morning vs. evening maximal cycle power and technical swimming ability

The aim of this study was to observe diurnal influences on maximal power and technical swimming ability at three different times (8 AM, 1 PM, and 6 PM). Prior to each test, tympanic temperature was taken. Maximal power was analyzed by cycle tests. Stroke length, stroke rate, hand pattern, and swimming velocity were recorded between the 20th and the 28th m of the 50-m freestyle. Temperature varied +/-0.4 degrees C between morning and evening. Concomitantly, maximal power (+7%) and technical ability (+3% in stroke length, +5% in stroke rate and changes in underwater hand coordinates) were greater in the evening. The present study confirms and specifies diurnal influences on all-out performances with regard to both maximal power and technical ability. Thus, when swimmers are called upon to perform at a high level in the morning, they should warm up extensively in order to "swamp" the diurnal effects of the morning.     

Staying alive

Quiescence is a state of reversible cell cycle arrest that can grant protection against many environmental insults. In some systems, cellular quiescence is associated with a low metabolic state characterized by a decrease in glucose uptake and glycolysis, reduced translation rates and activation of autophagy as a means to provide nutrients for survival. For cells in multiple different quiescence model systems, including Saccharomyces cerevisiae, mammalian lymphocytes and hematopoietic stem cells, the PI3Kinase/TOR signaling pathway helps to integrate information about nutrient availability with cell growth rates. Quiescence signals often inactivate the TOR kinase, resulting in reduced cell growth and biosynthesis. However, quiescence is not always associated with reduced metabolism; it is also possible to achieve a state of cellular quiescence in which glucose uptake, glycolysis and flux through central carbon metabolism are not reduced. In this review, we compare and contrast the metabolic changes that occur with quiescence in different model systems.     

Comparison of Olympic vs. traditional power lifting training programs in football players

Twenty members of an National Collegiate Athletic Association Division III collegiate football team were assigned to either an Olympic lifting (OL) group or power lifting (PL) group. Each group was matched by position and trained 4-days.wk(-1) for 15 weeks. Testing consisted of field tests to evaluate strength (1RM squat and bench press), 40-yard sprint, agility, vertical jump height (VJ), and vertical jump power (VJP). No significant pre- to posttraining differences were observed in 1RM bench press, 40-yard sprint, agility, VJ or in VJP in either group. Significant improvements were seen in 1RM squat in both the OL and PL groups. After log10-transformation, OL were observed to have a significantly greater improvement in Delta VJ than PL. Despite an 18% greater improvement in 1RM squat (p > 0.05), and a twofold greater improvement (p > 0.05) in 40-yard sprint time by OL, no further significant group differences were seen. Results suggest that OL can provide a significant advantage over PL in vertical jump performance changes.     

A comparison of absorbable and nonabsorbable suture materials for skin repair.

This prospective clinical study was conducted to compare the outcome of elective surgical wound repair in the occipital region during rhytidectomy using absorbable and nonabsorbable suture materials. On an alternative basis, 6-0 polypropylene and 6-0 plain catgut were used to repair the incisions on the upper and lower half of the surgical wounds in 80 sites. These sites were then compared for stitch marks, erythema, hypertrophic scars, infection, and wound necrosis. This study revealed slightly visible stitch marks in 4 of 40 (10 percent) sites repaired with catgut and in 10 of 40 (25 percent) sites repaired with polypropylene material (p less than 0.10); however, this was not statistically significant. There were five incidences of suture-site erythema (12.5 percent) noted in the group of catgut repairs in comparison with three incidences (7.5 percent) in the group repaired using polypropylene. Furthermore, there was no statistically significant difference in hypertrophic scarring or infection rate between these groups. The incidence of erythema following repair with catgut was higher, but this was also not statistically significant. Considering these findings, coupled with the avoidance of patient discomfort, suture removal, and time spared for the surgeon and staff when absorbable suture material is used, the superiority of plain catgut over nonabsorbable material becomes evident.     

Dynamic vs. static-stretching warm up: the effect on power and agility performance

The purpose of this study was to compare the effect of a dynamic warm up (DWU) with a static-stretching warm up (SWU) on selected measures of power and agility. Thirty cadets at the United States Military Academy completed the study (14 women and 16 men, ages 18-24 years). On 3 consecutive days, subjects performed 1 of the 2 warm up routines (DWU or SWU) or performed no warm up (NWU). The 3 warm up protocols lasted 10 minutes each and were counterbalanced to avoid carryover effects. After 1-2 minutes of recovery, subjects performed 3 tests of power or agility. The order of the performance tests (T-shuttle run, underhand medicine ball throw for distance, and 5-step jump) also was counterbalanced. Repeated measures analysis of variance revealed better performance scores after the DWU for all 3 performance tests (p < 0.01), relative to the SWU and NWU. There were no significant differences between the SWU and NWU for the medicine ball throw and the T-shuttle run, but the SWU was associated with better scores on the 5-step jump (p < 0.01). Because the results of this study indicate a relative performance enhancement with the DWU, the utility of warm up routines that use static stretching as a stand-alone activity should be reassessed.     

"Epidemic" vs "epidemiological": linguistic aspects of epidemiological terminology

The meaning of the terms "epidemic" and "epidemiological" used in a medical discourse have been analyzed; differential signs have been found by the method of linguistic analysis, making it possible to avoid unjustified interchanges of these terms.     

Short-term effects on lower-body functional power development: weightlifting vs. vertical jump training programs

Among sport conditioning coaches, there is considerable discussion regarding the efficiency of training methods that improve lower-body power. Heavy resistance training combined with vertical jump (VJ) training is a well-established training method; however, there is a lack of information about its combination with Olympic weightlifting (WL) exercises. Therefore, the purpose of this study was to compare the short-term effects of heavy resistance training combined with either the VJ or WL program. Thirty-two young men were assigned to 3 groups: WL = 12, VJ = 12, and control = 8. These 32 men participated in an 8-week training study. The WL training program consisted of 3 x 6RM high pull, 4 x 4RM power clean, and 4 x 4RM clean and jerk. The VJ training program consisted of 6 x 4 double-leg hurdle hops, 4 x 4 alternated single-leg hurdle hops, 4 x 4 single-leg hurdle hops, and 4 x 4 40-cm drop jumps. Additionally, both groups performed 4 x 6RM half-squat exercises. Training volume was increased after 4 weeks. Pretesting and posttesting consisted of squat jump (SJ) and countermovement jump (CMJ) tests, 10- and 30-m sprint speeds, an agility test, a half-squat 1RM, and a clean-and-jerk 1RM (only for WL). The WL program significantly increased the 10-m sprint speed (p < 0.05). Both groups, WL and VJ, increased CMJ (p < 0.05), but groups using the WL program increased more than those using the VJ program. On the other hand, the group using the VJ program increased its 1RM half-squat strength more than the WL group (47.8 and 43.7%, respectively). Only the WL group improved in the SJ (9.5%). There were no significant changes in the control group. In conclusion, Olympic WL exercises seemed to produce broader performance improvements than VJ exercises in physically active subjects.     

大山,留住了他们

最近常常会听到汉族的朋友们抱怨,虽然汉族人口众多,却连自己特有的极富民族特色的风俗与服装都不见了。其实,还是有这么一些汉族“少数民族”存在的,在深山中,固守着自己的服装和习惯,过得平静而祥和……     

"Living" under the challenge of information decay: the stochastic corrector model vs. hypercycles

The combined problem of having a large genome size when the accuracy of replication was a limiting factor is probably the most difficult transition to explain at the late stages of RNA world. One solution has been to suggest the existence of a cyclically coupled system of autocatalytic and cross-catalytic molecular mutualists, where each member helps the following member and receives help from the preceding one (i.e., a "hypercycle"). However, such a system is evolutionarily unstable when mutations are taken into account because it lacks individuality. In time, the cooperating networks of genes should have been encapsulated in a cell-like structure. But once the cell was invented, it closely aligned genes' common interests and helped to reduce gene selfishness, so there was no need for hypercycles. A simple package of competing genes, described by the "stochastic corrector model" (SCM), could have provided the solution. Until now, there is no clear demonstration that the proposed mechanisms (compartmentalized hypercycles and the stochastic corrector model) do in fact solve the error threshold problem. Here, we present a Monte Carlo model to test the viability of protocell populations that enclose a hypercyclic (HPC) or a non-hypercyclic (SCM) system when faced with realistic mutation rates before the evolution of efficient enzymic machinery for replication. The numerical results indicate that both systems are efficient information integrators and are able to overcome the danger of information decay in the absence of accurate replication. However, a population of SCM protocells can tolerate higher deleterious mutation rates and reaches an equilibrium mutational load lower than that in a population of HPC protocells.