Effects of Dieldrin on Reproduction of Penned Hen Pheasants

Pen studies to determine the effects of dieldrin on reproduction of the hen pheasant were conducted for two breeding seasons, Hen pheasants were caged individually and administered encapsulated dieldrin at weekly intervals. The first season, treatment levels were 0, 2 or 4 mg of dieldrin per hen per week. Hens receiving 4 mg weighed more and laid heavier eggs than the controls. However, these differences were not attributed to the effects of dieldrin, but to the condition of the hens when first treated. Hatchability of eggs from the 2 mg group was significantly higher for an undetermined reason. Feed consumption, egg production, fertility of eggs, and weight gain and survival of chicks were not affected by the treatments. The second season, treatment levels were 0, 2, 4 or 6 mg of dieldrin per hen per week. It appears that the 2 and 4 mg treatments did not influence feed consumption animal weight sufficiently to affect the rate of egg production. However, the 6 mg treatment significantly reduced feed consumption, hen weight and egg production. Egg weights appeared erratic and not directly affected by dieldrin. Fertility and hatchability of eggs and survival and weight gain of chicks were not reduced by the treatments. Possibly the 2 mg treatment had a slight stimulatory effect on her weight. The 6 mg treatment apparently affected reproduction by lowering the condition of the hens and reducing egg production

Agreement Between the Stages Cycling and SRM Powermeter Systems during Field-Based Off-Road Climbing.

The aim of this study was to determine the agreement between two portable cycling powermeters for use doing field based mountain biking. A single participant performed 15 timed ascents of an off-road climbs. The participants bicycle was instrumented with Stages Cycling and SRM powermeters. Mean and peak power output and cadence were recorded at 1 s intervals by both systems. Significant differences were determined using paired t-tests, whilst agreement was determined using 95% ratio limits of agreement (LoA). Significant differences were found between the two systems for mean power output (p<.001), with the Stages powermeter under reporting power by 8 % compared to the SRM. LoA for mean power output were 0.92 ×÷ 1.02 (95% LoA = 0.90 – 0.93). Peak power output was also significantly lower with the Stages powermeter (p=.02) by 5 % when compared to the SRM powermeter. LoA for peak power output were 0.94 ×÷ 1.09 (95% limits of agreement = 0.87 – 1.03). Significant differences were found for mean cadence between the two powermeters (p=.009), with LoA being 0.99 ×÷ 1.01 (95% limits of agreement = 0.99 – 1.00). This study found that though the Stages Cycling powermeter provided a reliable means of recording power output and cadence, the system significantly underestimated mean and peak power output when compared with the SRM system. This may in part be due to differences in strain gauge configuration and the subsequent algorithms used in the calculation of power output and the potential influence of bilateral imbalances within the muscles may have on these calculations

Influence of Course Type on Upper Body Muscle Activity in Elite Cross-Country and Downhill Mountain Bikers During Off Road Downhill Cycling

This study aimed to investigate upper body muscle activity using surface electromyography (sEMG) in elite cross-country (XCO) and downhill (DH) cyclists during off road descending and the influence of man-made (MM) and natural terrain (NT) descents on muscle activity. Twelve male elite mountain bikers (n=6 XCO; age 23 ± 4 yrs; stature 180.5 ± 5.6 cm; body mass 70.0 ± 6.4 kg and n=6 DH; age 20 ± 2 yrs; stature 178.8 ± 3.1 cm; body mass 75.0 ± 3.0 kg) took part in this study. sEMG were recorded from the left biceps brachii, triceps brachii, latissimus dorsi and brachioradialis muscles and expressed as a percentage of maximal voluntary isometric contraction (% MVIC). Both groups performed single runs on different MM and NT courses specific to their cycling modality. Significant differences in mean % MVIC were found between biceps brachii and triceps brachii (p=.016) and triceps brachii and latissimus dorsi (p=.046) during MM descents and between biceps brachii and triceps brachii (p=.008) and triceps brachii and latissimus dorsi (p=.031) during NT descents within the DH group. Significant differences in mean % MVIC were found between biceps brachii and brachioradialis (p=.022) for MM runs and between biceps brachii and brachioradialis (p=.013) for NT runs within the XCO group. Upper body muscle activity differs according to the type of downhill terrain, and appears to be specific to DH and XCO riders. Therefore, the discipline specific impact on muscle activation and the type of course terrain ridden should be considered when mountain bikers engage in upper body conditioning programmes

Manufacturing methods for machining spring ends parallel at loaded length

A first end surface of a coiled compression spring at its relaxed length is machined to a plane transverse to the spring axis. The spring is then placed in a press structure having first and second opposed planar support surfaces, with the machined spring end surface bearing against the first support surface, the unmachined spring end surface bearing against a planar first surface of a lateral force compensation member, and an opposite, generally spherically curved surface of the compensation member bearing against the second press structure support surface. The spring is then compressed generally to its loaded length, and a circumferentially spaced series of marks, lying in a plane parallel to the second press structure support surface, are formed on the spring coil on which the second spring end surface lies. The spring is then removed from the press structure, and the second spring end surface is machined to the mark plane. When the spring is subsequently compressed to its loaded length the precisely parallel relationship between the machined spring end surfaces substantially eliminates undesirable lateral deflection of the spring

The Reliability of Electromyographic Normalization Methods for Cycling Analyses

Electromyography (EMG) is normalized in relation to a reference maximum voluntary contraction (MVC) value. Different normalization techniques are available but the most reliable method for cycling movements is unknown. This study investigated the reliability of different normalization techniques for cycling analyses. Twenty‐five male cyclists (age 24.13 ± 2.79 years, body height 176.22 ± 4.87 cm and body mass 67.23 ± 4.19 kg, BMI = 21.70 ± 2.60 kg∙m‐1) performed different normalization procedures on two occasions, within the same testing session. The rectus femoris, biceps femoris, gastrocnemius and tibialis anterior muscles were examined. Participants performed isometric normalizations (IMVC) using an isokinetic dynamometer. Five minutes of submaximal cycling (180 W) were also undertaken, allowing the mean (DMA) and peak (PDA) activation from each muscle to serve as reference values. Finally, a 10 s cycling sprint (MxDA) trial was undertaken and the highest activation from each muscle was used as the reference value. Differences between reference EMG amplitude, as a function of normalization technique and time, were examined using repeated measures ANOVAs. The test‐retest reliability of each technique was also examined using linear regression, intraclass correlations and Cronbach’s alpha. The results showed that EMG amplitude differed significantly between normalization techniques for all muscles, with the IMVC and MxDA methods demonstrating the highest amplitudes. The highest levels of reliability were observed for the PDA technique for all muscles; therefore, our results support the utilization of this method for cycling analyses

Disorder prediction methods, their applicability to different protein targets and their usefulness for guiding experimental studies

The role and function of a given protein is dependent on its structure. In recent years, however, numerous studies have highlighted the importance of unstructured, or disordered regions in governing a protein’s function. Disordered proteins have been found to play important roles in pivotal cellular functions, such as DNA binding and signalling cascades. Studying proteins with extended disordered regions is often problematic as they can be challenging to express, purify and crystallise. This means that interpretable experimental data on protein disorder is hard to generate. As a result, predictive computational tools have been developed with the aim of predicting the level and location of disorder within a protein. Currently, over 60 prediction servers exist, utilizing different methods for classifying disorder and different training sets. Here we review several good performing, publicly available prediction methods, comparing their application and discussing how disorder prediction servers can be used to aid the experimental solution of protein structure. The use of disorder prediction methods allows us to adopt a more targeted approach to experimental studies by accurately identifying the boundaries of ordered protein domains so that they may be investigated separately, thereby increasing the likelihood of their successful experimental solution

Manufacturing methods for machining spring ends parallel at loaded length

A first end surface of a coiled compression spring at its relaxed length is machined to a plane transverse to the spring axis. The spring is then placed in a press structure having first and second opposed planar support surfaces, with the machined spring end surface bearing against the first support surface, the unmachined spring end surface bearing against a planar first surface of a lateral force compensation member, and an opposite, generally spherically curved surface of the compensation member bearing against the second press structure support surface. The spring is then compressed generally to its loaded length, and a circumferentially spaced series of marks, lying in a plane parallel to the second press structure support surface, are formed on the spring coil on which the second spring end surface lies. The spring is then removed from the press structure, and the second spring end surface is machined to the mark plane. When the spring is subsequently compressed to its loaded length the precisely parallel relationship between the machined spring end surfaces substantially eliminates undesirable lateral deflection of the spring

Influence of wheel size on muscle activity and tri-axial accelerations during Cross-Country mountain biking

This study aimed to investigate the influence of different mountain bike wheel diameters on muscle activity and whether larger diameter wheels attenuate muscle vibrations during cross-country riding. Nine male competitive mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) participated in the study. Riders performed one lap at race pace on 26, 27.5 and 29 inch wheeled mountain bikes. sEMG and acceleration (RMS) were recorded for the full lap and during ascent and descent phases at the gastrocnemius, vastus lateralis, biceps brachii and triceps brachii. No significant main effects were found by wheel size for each of the four muscle groups for sEMG or acceleration during the full lap and for ascent and descent (P > .05). When data were analysed between muscle groups, significant differences were found between biceps brachii and triceps brachii (P < .05) for all wheel sizes and all phases of the lap with the exception of for the 26 inch wheel during the descent. Findings suggest wheel diameter has no influence on muscle activity and vibration during mountain biking. However, more activity was observed in the biceps brachii during 26 inch wheel descending. This is possibly due to an increased need to manoeuvre the front wheel over obstacles

The Multifunctional Sorting Protein PACS-2 Regulates SIRT1-Mediated Deacetylation of p53 to Modulate p21-Dependent Cell-Cycle Arrest

SIRT1 regulates the DNA damage response by deacetylating p53, thereby repressing p53 transcriptional output. Here, we demonstrate that the sortingprotein PACS-2 regulates SIRT1-mediated deacetylation of p53 to modulate the DNA damage response. PACS-2 knockdown cells failed to efficiently undergo p53-induced cell-cycle arrest in response to DNA damage. Accordingly, p53 acetylation was reduced both in PACS-2 knockdown cells and thymocytes from Pacs-2-/- mice, thereby blunting induction of the cyclin-dependent kinase inhibitor p21 (CDKN1A). The SIRT1 inhibitor EX-527 or SIRT1 knockdown restored p53 acetylation and p21 induction as well as p21-dependent cell-cycle arrest in PACS-2 knockdown cells. Traffickingstudies revealed that cytoplasmic PACS-2 shuttled to the nucleus, where it interacted with SIRT1 andrepressed SIRT1-mediated p53 deacetylation. Correspondingly, invitro assays demonstrated that PACS-2 directly inhibited SIRT1-catalyzed p53 deacetylation. Together, these findings identify PACS-2 as an invivo mediator of the SIRT1-p53-p21 axis that modulates the DNA damage response