The efficiency of the close coupled cooling system for consolidated servers

大学の情報系センターにおけるサーバルームは、高速計算機の設置を前提として設計されていることが多い。しかしながら、近年では高速計算機の設置を取りやめる大学も増え、また設置されるサーバもラックマウントサーバやブレードサーバのように小型化し、単位面積当たりの発熱密度が増加している。さらにはサーバ仮想化技術の普及によって、サーバに搭載するCPU やメモリが増加し、サーバ単体の発熱量も増加する傾向にある。このような変化により、サーバルームに占めるサーバの設置面積は減少しつつも、サーバ単体の発熱量は増加している。そのため、空間的な熱の偏りが発生し、従来の部屋全体を冷却する方式では対応できないことがある。また、電力使用量の点からも適切でないと考えられる。これらの対策として、部屋全体を冷却するのではなくサーバを搭載するラックを集中的に冷却する、局所冷却方式が注目されている。鳥取大学総合メディア基盤センターでは、サーバルームの冷却方式について比較検討した結果、APC社製 InRow RP DX という精密空調装置とHACSソリューションを用いることで局所冷却を実現し、サーバの適切な冷却と電力使用量の削減を実現した

RESEARCH Open Access

polyphenols exert hypocholesterolemic effects in zebrafish fed a high-cholesterol die

Body fat accumulation in zebrafish is induced by a diet rich in fat and reduced by supplementation with green tea extract.

Fat-rich diets not only induce obesity in humans but also make animals obese. Therefore, animals that accumulate body fat in response to a high-fat diet (especially rodents) are commonly used in obesity research. The effect of dietary fat on body fat accumulation is not fully understood in zebrafish, an excellent model of vertebrate lipid metabolism. Here, we explored the effects of dietary fat and green tea extract, which has anti-obesity properties, on body fat accumulation in zebrafish. Adult zebrafish were allocated to four diet groups and over 6 weeks were fed a high-fat diet containing basal diet plus two types of fat or a low-fat diet containing basal diet plus carbohydrate or protein. Another group of adult zebrafish was fed a high-fat diet with or without 5% green tea extract supplementation. Zebrafish fed the high-fat diets had nearly twice the body fat (visceral, subcutaneous, and total fat) volume and body fat volume ratio (body fat volume/body weight) of those fed low-fat diets. There were no differences in body fat accumulation between the two high-fat groups, nor were there any differences between the two low-fat groups. Adding green tea extract to the high-fat diet significantly suppressed body weight, body fat volume, and body fat volume ratio compared with the same diet lacking green tea extract. 3-Hydroxyacyl-coenzyme A dehydrogenase and citrate synthase activity in the liver and skeletal muscle were significantly higher in fish fed the diet supplemented with green tea extract than in those fed the unsupplemented diet. Our results suggest that a diet rich in fat, instead of protein or carbohydrate, induced body fat accumulation in zebrafish with mechanisms that might be similar to those in mammals. Consequently, zebrafish might serve as a good animal model for research into obesity induced by high-fat diets

Distributed e-Learning System with Client-Server and P2P Hybrid Architecture

We have developed a distributed asynchronous Web based training system. In order to improve the scalability and robustness of this system, all contents and a function are realized on mobile agents. These agents are distributed to computers, and they can use a Peer to Peer network that modified Content-Addressable Network. In this system, all computers offer the function and exercise by themselves. However, the system that all computers do the same behavior is not realistic. In this paper, as a solution of this issue, we present an e-Learning system that is composed of computers of different participation types. Enabling the computer of different participation types will improve the convenience of the system

Coffee Polyphenol, Chlorogenic Acid, Suppresses Brain Aging and Its Effects Are Enhanced by Milk Fat Globule Membrane Components

Mice feed with coffee polyphenols (CPP, chlorogenic acid) and milk fat globule membrane (MFGM) has increased survival rates and helps retain long-term memory. In the cerebral cortex of aged mice, CPP intake decreased the expression of the proinflammatory cytokine TNF-α, and lysosomal enzyme cathepsin B. The suppression of inflammation in the brain during aging was thought to result in the suppression of the repressor element 1-silencing transcription factor (REST) and prevention of brain aging. In contrast, CPP increased the expression of REST, cAMP-responsive element binding (CREB) and transforming growth factor β1 (TGF-β1) in the young hippocampus. The increased expression of these factors may contribute to the induction of neuronal differentiation and the suppression of memory decline with aging. Taken together, these results suggest that CPP increases CREB in the young hippocampus and suppresses inflammation in the old brain, resulting in a preventive effect on brain aging. The endotoxin levels were not elevated in the serum of aged mice. Although the mechanism of action of MFGM has not yet been elucidated, the increase in survival rate with both CPP and MFGM intake suggests that adding milk to coffee may improve not only the taste, but also the function

Energy intake, body weight, feed efficiency, and body fat volume in zebrafish fed a low-fat (LF) or high-fat (HF) diet.

<p>Values are means ± SE.</p><p>^§<i>P</i> < 0.05</p><p>^§§<i>P</i> < 0.01 compared with LF1 diet.</p><p>^#<i>P</i> < 0.05</p><p>^##<i>P</i> < 0.01compared with LF2 diet.</p><p>Energy intake, body weight, feed efficiency, and body fat volume in zebrafish fed a low-fat (LF) or high-fat (HF) diet.</p

Body fat volume ratios in zebrafish fed low-fat (LF) or high-fat (HF) diets.

<p>For 6 weeks, female adult zebrafish were fed the LF1, LF2, HF1, or HF2 diet (<i>n</i> = 16 in each group). On the last day, fish were euthanized and body weights and body fat volumes were measured by using CT. Values are means ± SE. ^##<i>P</i> < 0.01 compared with LF1 diet. ^§<i>P</i> < 0.05 and ^§§<i>P</i> < 0.01 compared with LF2 diet.</p