360 research outputs found
THE EFFECT Of SHOULDER POSITION DIFFERENCE OF STREAMLINE POSTURE IN COMPETITIVE SWIMMERS
The objective of this study was to investigate the movements of the centers of buoyancy and mass and the change in the distance between the two centers because of the elevation of the shoulder joints. The total length increased by 5.7 em on an average because of the elevation of the shoulder joints. The positions of the center of mass with respect to the heels were 103.4 & 4.0 cm during depression and 104.2 i 4.1 cm during elevation. The center of buoyancy shifted toward the head more during elevation (105.9 i 4.2 cm) than during depression (105.1 * 4.1 em) during neutral buoyancy. Also, the distance between the centers of buoyancy and mass was smaller during elevation (1.60 * 0.20 cm) than during depression (1.66 * 0.21 cm) with 1% significance. This study suggests a possible effect of the shoulder position on maintaining a horizontal position
Numerical Simulation in Ulcer-Like Projection due to Type B Aortic Dissection with Complete Thrombosis Type
鶏凍結精子の走査電子顕微鏡による研究
最近走査電子顕微鏡による精子の形態学的研究が行なわれるようになり, 哺乳類の精子は凍結保存により先体に著しい悪影響を被ることが知られている。一方家禽精子においても哺乳類の精子と同様に融解精子先体に著しい変化の認められることが報告されているが, 凍結融解操作によってもたらされる一連の精子の損傷について観察した報告は少ない。
本研究は光学顕微鏡と走査電子顕微鏡を用い, 錠剤化凍結法とストロー凍結法により, それぞれ二種類の希釈液を用いて凍結処理し, 融解後の鶏精子の活力および崎形精子の微細構造について観察した。その結果, 走査電子顕微鏡を用いれば, 従来の光学顕微鏡下で通常認められる首曲り畸形精子の他に精子先体の離脱や, 精子頭部末部の膨化が認められた。しかし凍結法, 希釈液によるそれら畸形精子の出現割合の差異は明らかでなかった。Recently the scanning electron microscope (SEM) is currently being used to study the morphology of normal and abnormal spermatozoa. In general, it is known that the acrosome of mammalian spermatozoa is affected by deep freezing preservation. On the other hand, HARRIS et al. also reported that the acrosome of fowl spermatozoa is influenced by deep freezing as well as in that of mammalian spermatozoa. MARQUEZ et al. reported that some swelling or distortion of the mitochondria were caused when the turkey semen has been exposed to a glycerol containing medium. But there are few reports pertaining to the series of the morphological changes in fowl spermatozoa after freezing and thawing.
In the present study, the scanning electron microscope was used to observe the morphological changes observed in fowl spermatozoa before, during and after freezing and thawing of sperm cell
Factors Influencing the Number of Eggs Recovered from Rabbits Superovulated with FSH or PMSG: Analysis of Five Years of Data from 509 Rabbits
To determine the best conditions for superovulation in rabbits, we analyzed the influence of age, season and hormone treatment on the numbers of eggs collected over five years from 509 rabbits aged 4–10 months using follicular stimulating hormone (FSH) or pregnant mare serum gonadotropin (PMSG) hormone stimulation. The number of eggs recovered was significantly higher in younger rabbits in both treated groups (P < 0.01–0.05). The number of eggs collected from rabbits treated with FSH were significantly higher than from rabbits treated with PMSG at all ages (P < 0.01). Seasonal differences were not observed in either hormone treatment group as they were maintained under constant temperature, humidity and light cycle through the year. Thus, younger rabbits are more sensitive to hormonal superovulation treatment with both FSH and PMSG, and FSH offers a better regimen for egg collection
Periodicities of palaeo-climatic records extracted from the Dome Fuji deep core
The Antarctic ice sheet preserves palaeo-climate information in the form of physical and chemical stratigraphy. A deep ice core was continuously drilled down to a depth of 2503m at Dome Fuji Station, East Dronning Maud Land, Antarctica, during the 1993-97 JARE inland operations. A time scale for the Dome Fuji core is calculated from past accumulation rates and an ice flow model. A depth-age profile was obtained for the past 320kyr back in time. The obtained palaeo-temperature profile shows the past three glacial and interglacial periods. The power spectrum for oxygen isotope variation for 320kyr shows three dominant cycles of 107kyr, 40kyr and 21kyr. Each of these three cycles is similar to Milankovitch cycles. Moving-window spectrum analysis, using a 130kyr window stepped by 10kyr over the past 320kyr, found these main cycles in every age. Variations of other chemical concentrations were also recovered from the Dome Fuji ice core, and are inversely correlated to the temperature profile. Concentrations of terrestrial and marine origin substances are high in glacial periods, and low in interglacial periods. Over the past 320kyr, the dominant periodicities of temperature were also detected in almost all chemical records
Analysis of Infant Microbiota Composition and the Relationship With Breast Milk Components in the Asian Elephant (Elephas Maximus) at the Zoo
The prevention of diseases through health control is essential at zoos. Here, we investigated the gut microbiota formation during infancy in an Asian elephant and compared the composition between infant and mother. Besides, we analyzed the components of breast milk and examined the correlation with the infant gut microbiota. Analysis revealed the gut microbiota of the infant contained high amount of Lactobacillales and its diversity was relatively low compared to that of the mother. We found several milk components, showed a positive correlation with the change of Lactobacillales. The present study revealed the mechanism of gut microbiota formation during infancy in an Asian elephant and provides important insights into the health control of Asian elephants in zoos
S-Nitrosated alpha-1-acid glycoprotein exhibits antibacterial activity against multidrug-resistant bacteria strains and synergistically enhances the effect of antibiotics
Alpha-1-acid glycoprotein (AGP) is a major acute-phase protein. Biosynthesis of AGP increases markedly during inflammation and infection, similar to nitric oxide (NO) biosynthesis. AGP variant A (AGP) contains a reduced cysteine (Cys149). Previously, we reported that S-nitrosated AGP (SNO-AGP) synthesized by reaction with a NO donor, possessed very strong broad-spectrum antimicrobial activity (IC50 = 10−9-10−6 M). In this study, using a cecal ligation and puncture animal model, we confirmed that AGP can be endogenously S-nitrosated during infection. Furthermore, we examined the antibacterial property of SNO-AGP against multidrug-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa to investigate the involvement of SNO-AGP in the host defense system. Our results showed that SNO-AGP could inhibit multidrug efflux pump, AcrAB-TolC, a major contributor to bacterial multidrug resistance. In addition, SNO-AGP decreased biofilm formation and ATP level in bacteria, indicating that SNO-AGP can revert drug resistance. It was also noteworthy that SNO-AGP showed synergistic effects with the existing antibiotics (oxacillin, imipenem, norfloxacin, erythromycin, and tetracycline). In conclusion, SNO-AGP participated in the host defense system and has potential as a novel agent for single or combination antimicrobial therapy
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