Preliminary report of swimming behavior and the response to temperature of lacustrine masu salmon, Oncorhynchus masou Brevoort, monitored by data logger during the spawning migration in Lake Toya

Swimming depth and ambient water temperature of male masu salmon (Oncorhynchus masou Brevoort) during the spawning migration in Lake Toya was examined using a micro data logger. Soon after release, the fish swam along the coast and mean swimming depth and water temperature were 14.2±7.96m and 13.8±3.80℃. Then, the fish swam into a stream where mean swimming depth and water temperature were 1.6±3.28m and 18.3±1.58℃. The fish returned to the lake again where mean swimming depth and water temperature were 33.4±14.1m and 5.5±1.45℃. Finally, the fish swam into a stream again and stopped any vertical movements. The results show that the fish swam in coastal waters at a higher water temperature despite the likely higher energy expenditure and swam in deep, cooler water to recover between two upstream migration attempts. We hypothesize that temperature is not an important parameter for upstream migration and probably navigational mechanisms and hormonal motivation for spawning have affeted ambient temperature selection in lacustrine masu salmon during the spawning migration

有害金属拮抗薬DMSAおよびDMPSのヒ酸ナトリウムの排泄に対する作用

Previous studies have shown that DMSA (meso-2, 3-dimercaptosuccinic acid, succimer) and DMPS (2, 3-dimercapto-1-propane sulfonic acid, Na salt, unithiol) are effective antidotes for pentavalent arsenate and trivalent arsenite because they reduce the mortality of mice poisoned with these arsenic compounds. Studies have also shown that in mice treated with arsenite, DMPS and DMSA promote excretion of arsenic into the bile and urine, respectively. This study was conducted to determine whether DMSA and DMPS promote arsenate excretion to the same extent as previously reported for arsenite. The results demon-strated that DMPS antagonized arsenate toxicity by improving excretion of arsenic, although to a lesser extent than in studies with arsenite, while DMSA showed a slight but statistically insignificant promotion of early arsenic excretion in the urine

The Period and the Distribution of the Fibonacci-like Sequence Under Various Moduli

We reduce the Fibonacci sequence mod m for a natural number m, and denote it by F (mod m ). We are going to introduce the properties of the period and distribution of F (mod m). That is, how frequently each residue is expected to appear within a single period. These are well known themes of the research of the Fibonacci sequence, and many remarkable facts have been discovered. After that we are going to study the properties of period and distribution of a Fibonacci-like sequence that the authors introduced in article in the previous issue of Undergraduate Math Journal. This Fibonacci-like sequence also has many interesting properties, and the authors could prove an interesting theorem in this article. Some of properties are very difficult to prove, and hence we are going to present some predictions and calculations by computers

ビタミンE欠乏ラットのミトコンドリア酸化的リン酸化

　ラットを離乳直後からビタミンE 欠乏食で5~11 週間飼育し，欠之の徴候発現を確認したのち肝ミト コンドリアおよびそのジギトニン標品また心筋ミトコンドリアを調製し，数種のトリカルボン酸を基質 として酸化的リン酸化を測定した結果，E欠之によってとくに変化が認められなかった。しかしE欠乏 ミトコンドリアではα-ケトグルタル酸の酸化能が減退した

Time Trade-off Utility Analysis for Surgical Intervention in Comitant Strabismus, Glaucoma, and Cataract

The utility value was compared among 3 surgical interventions, and the validity of the time trade-off (TTO) method was evaluated by analyzing the correlations of the utility value with the results of the Visual Function Questionnaire-14 (VF-14) and other variables. The subjects were 127 patients aged 40-85 years who were surgically treated between January 2008 and March 2010, including 26 patients with glaucoma, 50 with cataracts, and 51 with comitant strabismus. The scores on VF-14 and utility values determined using TTO were calculated retrospectively. The mean value (SD) of the utility gain was 0.096 (0.105) for glaucoma, 0.101 (0.105) for comitant strabismus, and 0.167 (0.237) for unilateral and 0.245 (0.167) for bilateral cataracts, indicating significant postoperative improvements in the utility value. A significant correlation was observed between the utility value and the postoperative VF-14 scores of the bilateral cataracts, and the postoperative visual acuity of the better eye of the unilateral cataract. The mean value of the quality-adjusted life years was 2.181 for bilateral and 1.424 for unilateral cataracts, 1.132 for strabismus, and 0.870 for glaucoma with an annual discount rate of 3%. The gain of utility value was highest in bilateral cataracts, and lowest in glaucoma, and thus the TTO analysis was considered to be highly valid for cataract surgery

LATS1/2 kinases trigger self-renewal of cancer stem cells in aggressive oral cancer

Cancer stem cells (CSCs), which play important roles in tumor initiation and progression, are resistant to many types of therapies. However, the regulatory mechanisms underlying CSC-specific properties, including self-renewal, are poorly understood. Here, we found that LATS1/2, the core Hippo pathway-kinases, were highly expressed in the oral squamous cell carcinoma line SAS, which exhibits high capacity of CSCs, and that depletion of these kinases prevented SAS cells from forming spheres under serum-free conditions. Detailed examination of the expression and activation of LATS kinases and related proteins over a time course of sphere formation revealed that LATS1/2 were more highly expressed and markedly activated before initiation of self-renewal. Moreover, TAZ, SNAIL, CHK1/2, and Aurora-A were expressed in hierarchical, oscillating patterns during sphere formation, suggesting that the process consists of four sequential steps. Our results indicate that LATS1/2 trigger self-renewal of CSCs by regulating the Hippo pathway, the EMT, and cell division