Management of a Large Distributed Control System Development Project

Building an accelerator at six geographically dispersed sites is quite mad, but politically expedient. The Spallation Neutron Source (SNS), currently under construction in Oak Ridge, Tennessee, combines a pulsed 1 Gev H- superconducting linac with a compressor ring to deliver 2MW of beam power to a liquid mercury target for neutron production [1]. Accelerator components, target and experimental (neutron-scattering) instruments are being developed collaboratively by Lawrence Berkeley (Ion Source and Front End), Los Alamos (Linac), Thomas Jefferson (Cryosystems), Brookhaven (Compressor Ring), Oak Ridge (Target and Conventional Facilities) and Argonne (Neutron Scattering Instruments) National Laboratories. Similarly, a team distributed among all of the participating laboratories is developing the EPICS-based control system. This paper discusses the management model and strategies being used to address the unusual issues of organization, communication, standardization, integration and hand-off inherent in this widely-distributed project.Comment: 5 pages. Invited Paper delivered to the International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '01), Nov 27-30, San Jose CA. PSN# TUDI00

The SNS Cryogenic Control System: Experiences in Collaboration

The cryogenic system for the Spallation Neutron Source (SNS) is designed by Jefferson Laboratory (JLab) personnel and is based on the existing JLab facility. Our task is to use the JLab control system design [2] as much as practical while remaining consistent with SNS control system standards. Some aspects of the systems are very similar, including equipment to be controlled, the need for PID loops and automatic sequences, and the use of EPICS. There are differences in device naming, system hardware, and software tools. The cryogenic system is the first SNS system to be developed using SNS standards. This paper reports on our experiences in integrating the new and the old.Comment: 3 page

Satellite cell activity, without expansion, after nonhypertrophic stimuli

The purpose of the present studies was to determine the effect of various nonhypertrophic exercise stimuli on satellite cell (SC) pool activity in human skeletal muscle. Previously untrained men and women (men: 29 ± 9 yr and women: 29 ± 2 yr, n = 7 each) completed 6 wk of very low-volume high-intensity sprint interval training. In a separate study, recreationally active men ( n = 16) and women ( n = 3) completed 6 wk of either traditional moderate-intensity continuous exercise ( n = 9, 21 ± 4 yr) or low-volume sprint interval training ( n = 10, 21 ± 2 yr). Muscle biopsies were obtained from the vastus lateralis before and after training. The fiber type-specific SC response to training was determined, as was the activity of the SC pool using immunofluorescent microscopy of muscle cross sections. Training did not induce hypertrophy, as assessed by muscle cross-sectional area, nor did the SC pool expand in any group. However, there was an increase in the number of active SCs after each intervention. Specifically, the number of activated (Pax7+/MyoD+, P ≤ 0.05) and differentiating (Pax7−/MyoD+, P ≤ 0.05) SCs increased after each training intervention. Here, we report evidence of activated and cycling SCs that may or may not contribute to exercise-induced adaptations while the SC pool remains constant after three nonhypertrophic exercise training protocols

Cerebellar Asymmetry and Cortical Connectivity in Monozygotic Twins with Discordant Handedness

Handedness differentiates patterns of neural asymmetry and interhemispheric connectivity in cortical systems that underpin manual and language functions. Contemporary models of cerebellar function incorporate complex motor behaviour and higher-order cognition, expanding upon earlier, traditional associations between the cerebellum and motor control. Structural MRI defined cerebellar volume asymmetries and correlations with corpus callosum (CC) size were compared in 19 pairs of adult female monozygotic twins strongly discordant for handedness (MZHd). Volume and asymmetry of cerebellar lobules were obtained using automated parcellation.CC area and regional widths were obtained from midsagittal planimetric measurements. Within the cerebellum and CC, neurofunctional distinctions were drawn between motor and higher-order cognitive systems. Relationships amongst regional cerebellar asymmetry and cortical connectivity (as indicated by CC widths) were investigated. Interactions between hemisphere and handedness in the anterior cerebellum were due to a larger right-greater-than-left hemispheric asymmetry in right-handed (RH) compared to left-handed (LH) twins. In LH twins only, anterior cerebellar lobule volumes (IV, V) for motor control were associated with CC size, particularly in callosal regions associated with motor cortex connectivity. Superior posterior cerebellar lobule volumes (VI, Crus I, Crus II, VIIb) showed no correlation with CC size in either handedness group. These novel results reflected distinct patterns of cerebellar-cortical relationships delineated by specific CC regions and an anterior-posterior cerebellar topographical mapping. Hence, anterior cerebellar asymmetry may contribute to the greater degree of bilateral cortical organisation of frontal motor function in LH individuals

The pharmacological regulation of cellular mitophagy

Small molecules are pharmacological tools of considerable value for dissecting complex biological processes and identifying potential therapeutic interventions. Recently, the cellular quality-control process of mitophagy has attracted considerable research interest; however, the limited availability of suitable chemical probes has restricted our understanding of the molecular mechanisms involved. Current approaches to initiate mitophagy include acute dissipation of the mitochondrial membrane potential (ΔΨm) by mitochondrial uncouplers (for example, FCCP/CCCP) and the use of antimycin A and oligomycin to impair respiration. Both approaches impair mitochondrial homeostasis and therefore limit the scope for dissection of subtle, bioenergy-related regulatory phenomena. Recently, novel mitophagy activators acting independently of the respiration collapse have been reported, offering new opportunities to understand the process and potential for therapeutic exploitation. We have summarized the current status of mitophagy modulators and analyzed the available chemical tools, commenting on their advantages, limitations and current applications

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise.

addresses: Health and Biology, Liverpool Hope University, Liverpool, UK. [email protected]: Comparative Study; Journal ArticleThis is an Author's Accepted Manuscript of an article published in Journal of Sports Sciences, 2008, Vol. 26, Issue 10, pp. 1081 – 1090 © 2008 copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/02640410801930200Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise

Replication for Web Hosting Systems

Replication is a well-known technique to improve the accessibility of Web sites. It generally offers reduced client latencies and increases a site’s availability. However, applying replication techniques is not trivial, and various Content Delivery Networks (CDNs) have been created to facilitate replication for digital content providers. Th

The effect of age and unilateral leg immobilisation for 2 weeks on substrate ulilisation during moderate-intensity exercise in human skeletal muscle

Age and inactivity have been associated with intramuscular triglyceride (IMTG) accumulation. Here, we attempt to disentangle these factors by studying the effect of 2 weeks of unilateral leg immobilization on substrate utilization across the legs during moderate-intensity exercise in young (n = 17; 23 ± 1 years old) and older men (n = 15; 68 ± 1 years old), while the contralateral leg served as the control. After immobilization, the participants performed two-legged isolated knee-extensor exercise at 20±1W(_50% maximalwork capacity) for 45 min with catheters inserted in the brachial artery and both femoral veins.Biopsy samples obtained from vastus lateralis muscles of both legs before and after exercise were used for analysis of substrates, protein content and enzyme activities. During exercise, leg substrate utilization (respiratoryquotient) did not differ between groups or legs. Leg fatty acid uptake was greater in older than in young men, and although young men demonstrated net leg glycerol release during exercise, older men showed net glycerol uptake. At baseline, IMTG, muscle pyruvate dehydrogenase complex activity and the protein content of adipose triglyceride lipase, acetyl-CoA carboxylase 2 and AMP-activated protein kinase (AMPK)γ3 were higher in young than in older men. Furthermore, adipose triglyceride lipase, plasma membrane-associated fatty acid binding protein and AMPKγ3 subunit protein contents were lower and IMTG was higher in the immobilized than the contralateral leg in young and older men. Thus, immobilization and age did not affect substrate choice (respiratory quotient) during moderate exercise, but the whole-leg and molecular differences in fatty acid mobilization could explain the age- and immobilization-induced IMTG accumulation