Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is required so that the signal integration time can be as short as the Cherenkov light flash duration (a few ns). We have developed a readout board which samples waveforms of seven PMTs per board at a GHz rate. Since a GHz FADC has a high power consumption, leading to large heat dissipation, we adopted the analog memory ASIC "DRS4". The sampler has 1024 capacitors per channel and can sample the waveform at a GHz rate. Four channels of a chip are cascaded to obtain deeper sampling depth with 4096 capacitors. After a trigger is generated in a mezzanine on the board, the waveform stored in the capacitor array is subsequently digitized with a low speed (33 MHz) ADC and transferred via the FPGA-based Gigabit Ethernet to a data acquisition system. Both a low power consumption (2.64 W per channel) and high speed sampling with a bandwidth of $>$300 MHz have been achieved. In addition, in order to increase the dynamic range of the readout we adopted a two gain system achieving from 0.2 up to 2000 photoelectrons in total. We finalized the board design for the first LST and proceeded to mass production. Performance of produced boards are being checked with a series of quality control (QC) tests. We report the readout board specifications and QC results.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

Effect of soy protein on the muscle in human

Background : In recent years, the number of bedridden people is rapidly increasing due to aging or lack of exercise in Japan. This problem is becoming more serious, since there is no countermeasure against it. In the present study, we designed to investigate whether dietary proteins, especially soy, had beneficial effects on skeletal muscle in 59 volunteers with various physical activities. Methods : We subjected 59 volunteers with various physical activities to meal intervention examination. Persons with low and high physical activities were divided into two dietary groups, the casein diet group and the soy diet group. They ate daily meals supplemented with 7.8 g of powdered casein or soy protein isolate every day for 30 days. Bedridden patients in hospitals were further divided into three dietary groups : the no supplementation diet group, the casein diet group and the soy diet group. They were also subjected to a blood test, a urinalysis, magnetic resonance imaging analysis and muscle strength test of the knee before and after the meal intervention study. Results : Thirty-day soy protein supplementation significantly increased skeletal muscle volume in participants with low physical activity, compared with 30-day casein protein supplementation. Both casein and soy protein supplementation increased the volume of quadriceps femoris muscle in bedridden patients. Consistently, soy protein significantly increased their extension power of the knee, compared with casein protein. Although casein protein increased skeletal muscle volume more than soy protein in bedridden patients, their muscle strength changes by soy protein supplementation were bigger than those by casein protein supplementation. Conclusions : The supplementation of soy protein would be one of the effective foods which prevent the skeletal muscle atrophy caused by immobilization or unloading

Effects of pharmacist intervention in Vancomycin treatment for patients with bacteremia due to Methicillin-resistant Staphylococcus aureus.

OBJECTIVE:We conducted a retrospective study based on composite endpoints for treatment failure to evaluate the effect of pharmacist-led VCM initial dose planning for Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia patients. METHODS:A retrospective cohort study was performed between pharmacist intervention and non-intervention groups. In this study, four types of failure were defined as the composite endpoint. When any one of the following failures occurred: 1) Death within 30 days from the start of VCM therapy, 2) Positive blood culture 7 days after the start of VCM therapy, 3) Change of VCM to another anti-MRSA agent, and 4) Development of nephrotoxicity, we considered that VCM treatment had failed. Survival time analysis was conducted with the Kaplan-Meier method and Cox's proportional hazard model that included seven predefined parameters: pharmacist intervention, age, sex, weight, baseline VCM trough concentration, Charlson Comorbidity Index (CCI), and Pitt Bacteremia score (PBS). The effect of pharmacist intervention was studied as the survival probability estimated from the period of time from the start of VCM administration to the earliest failure. RESULTS:The survival rate at 30 days after starting VCM therapy, at the end of follow-up, was 53.1 and 82.1% in the non-intervention and intervention groups, respectively. A significant survival time prolongation was noted in the intervention group (p = 0.011, log rank test). Among the seven parameters, only pharmacist intervention was significantly different and its hazard ratio was 0.26 (p = 0.014). The survival probability of the intervention group was higher than that of the non-intervention group for the time to each failure. In subgroup analyses, a significant difference was noted in male patients between the intervention and non-intervention groups (p = 0.005). Age was categorized into those under and over 65 years old. For those over 65 years old, a significant difference was shown between the groups (p = 0.018). CONCLUSION:To our knowledge, this is the first study to evaluate the failure of VCM treatment based on the composite endpoint. Pharmacist intervention through the initial VCM dose planning could maintain a balance between the efficacy and safety of VCM treatment and might avoid treatment failure for patients with MRSA bacteremia. Further investigations with large sample sizes are required to confirm our findings

Simple separation of good quality bovine oocytes using a microfluidic device

We fabricated a simple microfluidic device for separation of bovine oocytes based on the oocyte quality to improve the conception rate of in vitro fertilization (IVF) by using good quality oocytes. The microfluidic device separates oocytes based on sedimentation rate differences in a sucrose buffer, which is dependent on oocyte quality. The microfluidic device has a 700 mu m width, 1 mm height, and 10 mm long separation channel. Oocytes were injected from the upper half of the separation channel, and they flowed while sinking. The outlets of the separation channel were divided into upper and lower chambers. Good quality oocytes settled faster than poor quality oocytes in sucrose buffer; therefore, good quality oocytes were collected from the lower outlet. We performed IVF after the microfluidic separation of oocytes. The developmental rate to blastocysts of oocytes collected from the lower outlet was significantly higher than those collected from the upper outlet (36.0% vs. 14.1%). This result was comparable to that in the BCB staining method performed as a comparison method (BCB+ : 35.7%, BCB-: 15.4%). These findings indicate that our microfluidic device could be applied to oocyte separation and contribute to improvement of in vitro embryo production system

Anagrelide Modulates Proplatelet Formation Resulting in Decreased Number and Increased Size of Platelets

Abstract. We retrospectively evaluated 48 essential thrombocythemia (ET) patients who were treated in our institute (male/female, 14/34, median age, 61.5 years). In 14 patients treated with anagrelide (ANA), the degree of platelet count reduction (median, −56.6%) was strongly correlated with increase of mean platelet volume (MPV) (median, +11.7%) (R = 0.777). This correlation was not observed in ET patients treated with hydroxycarbamide alone (R = 0.245). The change in size of platelets strongly suggested that ANA affected the final process of platelet production. Thus, we hypothesized that ANA modifies the process by which platelets are released from proplatelets. To verify the association in an in vitro setting, we compared MEG-01 cells treated with PMA ± ANA. The number of platelet-like particles (PLPs) was decreased (P < 0.05) and the size of PLPs estimated by using flow cytometry was significantly increased when MEG-01 cells were treated with PMA + ANA (P < 0.05 vs PMA alone), recapitulating the clinical findings. The cytoplasmic protrusions extending from MEG-01 cells were shorter and thicker and the number of proplatelets was decreased when MEG-01 cells were treated with PMA + ANA (P < 0.01 vs PMA alone). Western blotting analysis showed that ANA treatment resulted in increased phosphorylation of MLC2 and reduced phosphorylation of focal adhesion kinase (FAK). The morphological change of proplatelets were reversed by blebbistatin, a specific inhibitor of myosin II. These findings indicated that ANA modulates the FAK-RhoA-ROCK-MLC2-myosine IIA pathway and suppresses proplatelet maturation, leading to a decrease in platelet count and increase in MPV