Adaptation of the muscles of mastication to the flat skull feature in the polar bear (Ursus maritimus)     

Sasaki M  Endo H  Yamagiwa D  Takagi H  Arishima K  Makita T  Hayashi Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(1):7-14

The muscles of mastication of the polar bear (Ursus maritimus) and those of the brown bear (U. arctos) were examined by anatomical approach. In addition, the examination of the skull was carried out in the polar bear, brown bear and giant panda (Ailuropoda melanoleuca). In the polar bear, the rostro-ventral part of the superficial layer of the M. masseter possessed the abundant fleshy portion folded in the rostral and lateral directions like an accordion. Moreover, the rostro-medial area of the superficial layer became hollow in the nuchal direction when the mouth was closed. The M. temporalis of the polar bear covered up the anterior border of the coronoid process of the mandible and occupied the almost entire area of the cranial surface. The M. pterygoideus medialis of the polar bear was inserted on the ventral border of the mandible and on the ventral part of the temporal bone more widely than that of the brown bear. As results of our measurements of the mandible, an effect of the leverage in the polar bear was the smallest in three species. In the polar bear, the skull was flat, and the space between zygomatic arch and ventral border of the mandible, occupied by the M. masseter was the narrowest. It is suggested that the muscles of mastication of the polar bear is adapted to the flat skull feature for supplementing the functions.  相似文献   

The effects of potato pulp and feeding level of supplements on digestibility, in situ forage degradation and ruminal fermentation in beef steers     

Masahito SUGIMOTO  Waka SAITO  Motoki OOI  Yukinobu SATO  Toshiro SAITO  Kiyokazu MORI 《Animal Science Journal》2006,77(6):587-594

Six ruminally cannulated Wagyu (Japanese Black) steers (average initial bodyweight (BW) 387 ± 29 kg) were used in a split‐plot design experiment, comprising a 3 × 3 Latin square design (whole plot) and a randomized block design (subplot). The whole plot treatments were three different feeding levels of supplemental diet, fed at 0.2, 0.4 and 0.6% of BW, on a dry matter (DM) basis. Subplot treatments were two different supplemental diets: a potato pulp silage‐based diet (PPS) and a grain‐based diet (GRAIN). Chopped, medium‐quality cool‐season grass hay (predominately Timothy, Phleum pratense L) was fed daily at 0.7% BW (on a DM basis) as the basal diet. Each period consisted of 21 d, which included 11 d of adaptation to the diets and 10 d of the collection period. Chromium oxide was used as an indigestible marker. In situ forage degradation was measured using the nylon bag technique. The dry matter intake increased (linear; P < 0.01) as the feeding level increased and was not affected by the diet. Digestibility was not affected by any treatments. The GRAIN diet tended to decrease the rate of in situ forage degradation as the feeding level increased, but this trend was not found in the steers fed the PPS diet. Steers fed the GRAIN diet had a lower (P < 0.1) ruminal pH compared with steers fed the PPS diet. Ruminal pH was not significantly affected by feeding level; however, it was numerically higher for steers supplemented at 0.2% per BW than that for the steers supplemented above 0.4% per BW due probably to the higher starch intake. The total volatile fatty acids concentration numerically increased as the feeding level increased and was not affected by the diet. Increasing the feeding level decreased (linear, P < 0.01) the proportion of acetate. Neither diet nor the feeding level had any effects on the proportion of ruminal propionate. The results suggested that, for steers fed the PPS diet, there are not adverse effects on forage digestion in the rumen that occur as the feeding level is increased.  相似文献   

Lesion-based analysis of leaf blast suppression in mixture of rice cultivar and a resistant near-isogenic line     

Taketo Ashizawa  Masashi Sasahara  Atsushi Ohba  Takeshi Hori  Kouji Ishikawa  Yukio Sasaki  Tomohisa Kuroda  Ryoei Harasawa  Kaoru Zenbayashi-Sawata  Shinzo Koizumi 《Journal of General Plant Pathology》2007,73(1):15-21

Leaf blast suppression in multilines was evaluated based on the number of susceptible lesions observed in a pure stand of susceptible rice cultivar Sasanishiki, and in 1 : 1 and 1 : 3 mixtures of Sasanishiki and a resistant near-isogenic line, Sasanishiki BL4 or BL7, from 1998 to 2001. The number of lesions first observed in fields in the 1 : 1 and 1 : 3 mixtures were close to theoretical numbers calculated using the number of lesions observed in the pure stands and the ratios of the susceptible Sasanishiki in the mixtures. The ratio of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand was 0.29 and 0.09, respectively. The relationship between these ratios and the ratios of susceptible Sasanishiki in mixtures was defined in an equation to estimate the degree of leaf blast suppression. Validation studies for the ratios of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand were conducted in two different locations and showed that the ratios are almost acceptable. The calculated autoinfection to alloinfection ratio was 1.3 and 1.4 in the 1 : 1 and 1 : 3 mixtures, respectively, suggesting that the calculated ratio will affect the degree of leaf blast suppression. Thus, predictors were obtained to estimate leaf blast suppression for effective blast control in multilines.  相似文献   

Bone marrow hypoplasia induced by administration of estradiol benzoate in male beagle dogs     

N Miura  N Sasaki  H Ogawa  A Takeuchi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1985,47(5):731-739

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Development of a special alligator forceps for removal of pulmonary heartworms in very small dogs     

K Ishihara  Y Sasaki  H Kitagawa  S Kitao  N Takehashi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(1):159-161

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Multiplication of attenuated and virulent porcine parvoviruses in colostrum-deprived, neonatal pigs     

M Kubota  A Izumida  H Takuma  K Kodama  N Sasaki 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(6):1229-1235

Colostrum-deprived, neonatal, 2 days old pigs were inoculated with the attenuated HT-/SK or the virulent 90HS strain of porcine parvovirus (PPV) by the oral or subcutaneous route and sacrificed 2, 4 or 6 days after inoculation. Then, comparison was made on viral multiplication in pigs between the two strains. Pigs inoculated with the HT-/SK strain showed no detectable viremia or HI antibody responses against PPV within 6 days after inoculation. Only in pigs inoculated by the subcutaneous route, a small amount of virus was recovered from the spleen, liver, or mesenteric lymph nodes. These viruses were distinguished from the parental virulent 90HS strain, as examined for rct maker in vitro. When pigs were inoculated with the virulent 90HS strain, viremia appeared in all of them 1 day after inoculation and continued for up to the sacrificed day. Moreover, a considerable amount of virus was also detected from all tissues, including brain, lung, liver, spleen, pancreas, small intestine, and lymph node tissues, in all pigs tested. HI antibodies were first detected 6 days after inoculation.  相似文献   

Clinical studies on canine dirofilarial hemoglobinuria: blood coagulation system findings     

H Kitagawa  Y Sasaki  K Ishihara 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1985,47(4):575-580

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Plywood frame corner joints with glued-in hardwood dowels     

J?rgen Lauritzen Jensen  Takanobu Sasaki  Akio Koizumi 《Journal of Wood Science》2002,48(4):289-294

This paper presents research on plywood frame corners jointed to glulam beams and columns by means of glued-in hardwood dowels. The frame corner was made of a solid block of ordinary plywood of the same width as the glulam beams and with plies parallel to the plane of the frame to avoid splitting due to stress perpendicular to the grain. Hardwood dowels with a diameter of 12mm and a maximum glued-in length of 120mm were glued into drilled holes in the plywood corner and glulam beam ends parallel to the grain direction of the beams to form a momentresisting joint. Static bending tests were conducted of frame corners with 100 X 200mm² and 120 X 420mm² beam cross sections. Bending capacities of the joints corresponding to a modulus of rupture of the jointed glulam beams of about 30MPa were obtained for both closing and opening moments for the small cross sections, and about 22MPa was obtained for the large cross sections. Simple design models for calculation of joint strength and rotational stiffness are also presented.  相似文献   

Stress analysis of wood     

Takamaro Maku  Hikaru Sasaki 《Wood Science and Technology》1968,2(3):207-212

Summary For the preparation of specimens for testing the stress distribution with the photoelastic method, various techniques are applicable. In this paper the so-called glass-transition temperature method is tested on a specimen imitating the layered structure of wood. The observations made on this specimen are compared with those obtained from a specimen with isotropic properties.

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Zusammenfassung Für die Herstellung von Modellen zur Untersuchung der Spannungsverteilung mit spannungsoptischen Verfahren gibt es verschiedene Techniken. In dieser Mitteilung wird das sogenannte Glas-Übergangstemperatur-Verfahren an einem Modell, das den Schichtaufbau des Holzes nachahmt, geprüft. Die Beobachtungen, die an diesem Modell gemacht wurden, werden mit jenen verglichen, die sich an einem Modell mit isotropen Eigenschaften ergaben.

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Production of particleboard with steam-injection     

Mr. T. Hata  Dr. S. Kawai  Prof. Dr. H. Sasaki 《Wood Science and Technology》1990,24(1):65-78

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