The course changes in maximal strength velocity following a traditional strength- or power orientated training session

The primary aim of this study was to investigate the return to baseline of movement velocity and maximal strength following a typical strength-orientated and power-orientated session in the full depth, free-weight back squat performed with maximal concentric velocity. Fourteen strength-trained males completed a power-orientated session (3-sets of 6-repetitions @50% of a one-repetition maximum [1RM]) and a strength-orientated session (5-sets of 5-repetitions @80%1RM) in randomised order over two weeks. At 24, 48, 72 and 96-hours following the training session stimulus, sessions were completed with loads of 20%, 40%, 60%, 80%, 90% and 100%1RM lifted. Prior to the completion of the training sessions, individualised baseline load-velocity profiles were conducted based on the relative loads 20%, 40%, 60%, 80% and 90%1RM. Paired sample T-tests and effect sizes (ES) using Cohen’s D reported differences in mean velocity (MV), peak velocity (PV) and peak force for each relative load at baseline and each time point for all participants. 1RM was also compared between baseline and each time point. Large (≥0.80) and medium (0.50 to 0.79) ES were reported for MV and PV at loads of 60% and above until 72h after the strength-orientated training protocol. Small (0.20 to 0.49) to trivial

Readiness to train: Return to baseline strength and velocity following strength or power training

This study investigated the return to baseline of movement velocity and maximal strength following a strength-orientated session and power-orientated session in the free-weight back-squat performed with maximal concentric velocity. Fourteen strength-trained males completed a strength-orientated session (five sets of five repetitions @80% of a one-repetition maximum) and a power-orientated session (three sets of six repetitions @50% one-repetition maximum ) in a randomised order over two weeks (e.g. strength week 1, power week 2). The back-squat was then performed with loads of 20%, 40%, 60%, 80%, 90% and 100% one-repetition maximum at 24, 48, 72 and 96 h following the strength and power exercise sessions to assess return to baseline of squat velocity and maximal strength. Dependent variables included one-repetition maximum, back-squat mean velocity and peak velocity and countermovement jump peak velocity. Meaningful changes ((effect size) ≥ −0.60) were reported for mean velocity and peak velocity at loads ≥ 60% one-repetition maximum at 24 and 48 h after the strength-orientated session. Trivial to small (effect size ≤ −0.59) differences were reported for squat velocities following the power-orientated session. Only trivial to small effect size differences were observed for countermovement jump peak velocity and one-repetition maximum at all time points following both sessions. Squat velocity (mean velocity and peak velocity) across the load–velocity profile had recovered at 72 h following the strength-orientated session. However, the return to baseline of squat velocity (mean velocity and peak velocity) did not coincide with the return to baseline of one-repetition maximum or countermovement jump peak velocity. Therefore, measuring and monitoring meaningful changes in velocity may be a more valid and practical alternative in determining full recovery and readiness to train

Flow Dynamics And Plasma Heating Of Spheromaks In SSX

We report several new experimental results related to flow dynamics and heating from single dipole-trapped spheromaks and spheromak merging studies at SSX. Single spheromaks (stabilized with a pair of external coils, see Brown, Phys. Plasmas 13 102503 (2006)) and merged FRC-like configurations (see Brown, Phys. Plasmas 13, 056503 (2006)) are trapped in our prolate (R = 0.2 m, L = 0.6 m) copper flux conserver. Local spheromak flow is studied with two Mach probes (r(1) = rho(i) ) calibrated by time-of-flight with a fast set of magnetic probes at the edge of the device. Both Mach probes feature six ion collectors housed in a boron nitride sheath. The larger Mach probe will ultimately be used in the MST reversed field pinch. Line averaged flow is measured by ion Doppler spectroscopy (IDS) at the midplane. The SSX IDS instrument measures with 1 mu s or better time resolution the width and Doppler shift of the C-III impurity (H plasma) 229.7 nm line to determine the temperature and line-averaged flow velocity (see Cothran, RSI 77, 063504 (2006)). We find axial flows up to 100 km/s during formation of the dipole trapped spheromak. Flow returns at the wall to form a large vortex. Recent high-resolution IDS velocity measurements during spheromak merging show bi-directional outflow jets at +/- 40 km/s (nearly the Alfven speed). We also measure T-i \u3e= 80 eV and T-e \u3e= 20 eV during spheromak merging events after all plasma facing surfaces are cleaned with helium glow discharge conditioning. Transient electron heating is inferred from bursts on a four-channel soft x-ray array. The spheromaks are also characterized by a suite of magnetic probe arrays for magnetic structure B(r,t), and interferometry for n(e) . Finally, we are designing a new oblate, trapezoidal flux conserver for FRC studies. Equilibrium and dynamical simulations suggest that a tilt-stable, oblate FRC can be formed by spheromak merging in the new flux conserver

Bridging in vitro and in vivo testing: The utilisation of a novel in vitro three-dimensional model of human bone marrow for toxicity and genotoxicity testing

Genotoxicity testing is required for all new compounds utilising 2D assays, such as the in vitro micronucleus (MN) assay, before moving to in vivo assays such as the rodent bone marrow MN assay. Two-dimensional cell culture has traditionally been used for in vitro research. However, the in vivo setting comprises a three-dimensional (3D) environment and within the bone marrow (BM), mesenchymal and haematopoietic stem cells interact together. It has been found that even though the in vitro MN assay is intended to be predictive of the in vivo BM, glucocorticoids were found to have an increased level of micronuclei in vivo than predicted within the in vitro MN assay, therefore these have been labelled pharmacological positives. As 3D cell culture has been shown to simulate the in vivo scenario more closely, the aim of the current study was to create a reproducible model of the BM, using cell lines, which simulates the level of genotoxicity and cytotoxicity seen with the in vivo setting, for eventual use of identifying the mechanism(s) by which this change in MN induction occurs. Initially, an appropriate scaffold was identified for the primary culture of the fibroblast cell line HS-5. Once evaluated, a pre-culture of HS-5cells on the scaffold established a microenvironment suitable for later seeding of the TK6 cell line. Together with medium changes and optimised seeding a model was developed which supported an exponential phase of growth suitable for executing the MN assay in three-dimensions. Utilising this novel 3D model, TK6 cells were then dosed with known genotoxic positive (mitomycin c, etoposide and paclitaxel), negative (caffeine) and pharmacological positive (dexamethasone and prednisolone) compounds for induction of micronuclei in comparison to in vitro and historical in vivo data. The expression of 84 genes associated with metabolism was compared between 2D HS-5 vs 3D HS-5 ±TK6 to identify if this may play a role in the induction of MN. Those expressed in 3D HS-5 ±TK6 were more comparable to the in vivo BM than those HS-5 grown in 2D. In conclusion, this 3D in vitro model simulates the induction of genotoxic and cytotoxic damage of compounds, seen within the in vivo BM, with more accuracy than the conventional 2D in vitro MN assay. This research provides a more in vivo relevant setting for further in vitro investigation of the mechanism behind compound toxicity allowing a safe drug discovery pathway

Characterizing the query behavior in peer-to-peer file sharing systems

This paper characterizes the query behavior of peers in a peer-to-peer (P2P) file sharing system. In contrast to previous work, which provides various aggregate workload statistics, we characterize peer behavior in a form that can be used for constructing representative synthetic workloads for evaluating new P2P system designs. In particular, the analysis exposes heterogeneous behavior that occurs on different days, in different geographical regions (i. e., Asia, Europe, and North America) or during different periods of the day. The workload measures include the fraction of connected sessions that are passive (i. e., issue no queries), the duration of such sessions, and for each active session, the number of queries issued, time until first query, query interarrival time, time after last query, and distribution of query popularity. Moreover, the key correlations in these workload measures are captured in the form of conditional distributions, such that the correlations can be accurately reproduced in a synthetic workload. The characterization is based on trace data gathered in the Gnutella P2P system over a period of 40 days. To characterize system-independent user behavior, we eliminate queries that are specific to the Gnutella system software, such as re-queries that are automatically issued by some client implementations to improve system responsiveness

The theory and practice of electricity pricing policy : alternatives for the State Electricity Commission of Victoria

This study endeavours to show how the social and political influences of the environment within which an electricity undertaking operates can be incorporated into an economically efficient pricing policy. We have taken one undertaking, the State Electricity Commission of Victoria (SECV), and closely examined the outside influences on its pricing policy. We then show how these influences can be included in a pricing system which reflects costs more accurately than does the existing system. The study is in three parts. In Part A we discuss the theory of Peak Load Pricing and reconcile this theory with the work done on optimizing welfare under a budget constraint. Part B is devoted to an examination of the social and political factors which influence the SECV's pricing policy. In Part C, the final two chapters, we explain the SECV's present pricing policy and present an alternative which retains all of the existing outside influences explained in Part B while reflecting the economic costs of supply

Classification of Human Retinal Microaneurysms Using Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography

Purpose. Microaneurysms (MAs) are considered a hallmark of retinal vascular disease, yet what little is known about them is mostly based upon histology, not clinical observation. Here, we use the recently developed adaptive optics scanning light ophthalmoscope (AOSLO) fluorescein angiography (FA) to image human MAs in vivo and to expand on previously described MA morphologic classification schemes. Methods. Patients with vascular retinopathies (diabetic, hypertensive, and branch and central retinal vein occlusion) were imaged with reflectance AOSLO and AOSLO FA. Ninety-three MAs, from 14 eyes, were imaged and classified according to appearance into six morphologic groups: focal bulge, saccular, fusiform, mixed, pedunculated, and irregular. The MA perimeter, area, and feret maximum and minimum were correlated to morphology and retinal pathology. Select MAs were imaged longitudinally in two eyes. Results. Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging revealed microscopic features of MAs not appreciated on conventional images. Saccular MAs were most prevalent (47%). No association was found between the type of retinal pathology and MA morphology (P = 0.44). Pedunculated and irregular MAs were among the largest MAs with average areas of 4188 and 4116 μm2, respectively. Focal hypofluorescent regions were noted in 30% of MAs and were more likely to be associated with larger MAs (3086 vs. 1448 μm2, P = 0.0001). Conclusions. Retinal MAs can be classified in vivo into six different morphologic types, according to the geometry of their two-dimensional (2D) en face view. Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging of MAs offers the possibility of studying microvascular change on a histologic scale, which may help our understanding of disease progression and treatment response