Effects of silvopastoral areas on milk production at dual-purpose cattle farms at the semi-humid old agricultural frontier in central Nicaragua     

Wataru Yamamoto  Ioan Ap Dewi  Muhammad Ibrahim 《Agricultural Systems》2007

In extensive cattle production systems, the composition of grazing areas may significantly influence productivity. In dual-purpose cattle production systems in the lowland tropics, pasture lands with trees, so-called silvopastoral areas, are considered as being important, particularly to facilitate the management of crossbred European native cattle. The aim of the study was to quantify the effects of silvopastoral areas on production at dual-purpose cattle farms in the semi-humid lowlands of central Nicaragua. The relationships between seasonal milk production and herd data, and the proportions of land use types were examined for 74 farms by stepwise regression analysis.  相似文献   

Evaluation of high sensitive DNA probe for the detection of Theileria sergenti infection in cattle.   总被引：2，自引：0，他引：2  

A Hirano  R Kirisawa  T Matsuba  R Komatsu  M Tanaka  K Takahashi  Y Kawakami  M Onuma 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(5):933-935

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Abnormal structural luteolysis in ovaries of the senescence accelerated mouse (SAM): expression of Fas ligand/Fas-mediated apoptosis signaling molecules in luteal cells     

Kiso M  Manabe N  Komatsu K  Shimabe M  Miyamoto H 《The Journal of reproduction and development》2003,49(6):457-463

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Central and peripheral concentrations of tumor necrosis factor-alpha in Chinese Meishan pigs stimulated with lipopolysaccharide     

Sakumoto R  Kasuya E  Komatsu T  Akita T 《Journal of animal science》2003,81(5):1274-1280

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Classification of abomasal displacement in cows according to histopathology of the liver and clinical chemistry     

Komatsu Y  Itoh N  Taniyama H  Kitazawa T  Yokota H  Koiwa M  Ohtsuka H  Terasaki N  Maeno K  Mizoguchi M  Takeuchi Y  Tanigawa M  Nakamura T  Watanabe H  Matsuguchi Y  Kukino T  Honma A 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2002,49(9):482-486

Histopathological features of livers and blood chemical values in cows with abomasal displacement were investigated. Liver biopsy samples were collected during redressment operations in 92 cows with abomasal displacement, and the samples were stained with haematoxylin and eosin or periodic acid Schiff (PAS). Blood was collected for chemical tests. Livers were histopathologically divided into the following four types: normal histology cases (21%), fatty degeneration cases (36%), cloudy swelling cases (19%) and fatty degeneration cases with cloudy swelling (24%). The number of PAS-positive samples was significantly higher in the normal histology group and significantly lower in the severe fatty degeneration group and severe cloudy swelling group. Cows with fatty degeneration had significantly higher levels of serum 3-hydroxybutyric acid, non-esterified fatty acid and aspartate aminotransferase than did those with cloudy swelling or normal histology. The results indicate that the morbid conditions of cows with abomasal displacement can be classified into four types.  相似文献   

In vitro detection of equine arteritis virus from seminal plasma for identification of carrier stallions   总被引：1，自引：0，他引：1  

Fukunaga Y  Wada R  Sugita S  Fujita Y  Nambo Y  Imagawa H  Kanemaru T  Kamada M  Komatsu N  Akashi H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(6):643-646

Equine arteritis virus (EAV) was readily isolated in RK-13 cell monolayers by plaque assay from seminal plasma of experimental carrier stallions when they contained high titers of virus regardless of the presence of non-viral cytotoxicity in the seminal plasma. The cytotoxicity interfered with virus isolation from seminal plasma which contained virus at titers less than 10 PFU/ml. However, it was possible to detect the virus in seminal plasma pretreated with PEG (#6000). EAV was consistently identified by RT-PCR from crude seminal plasma which contained virus at titers of more than 10(2.7) PFU/ml. In vitro detection of EAV by virus isolation supplemented with RT-PCR using seminal plasma was proved to be an effective alternative to the standard test mating as a diagnostic method for carrier stallions.  相似文献   

Preliminary experiments on mechanical stretch-induced activation of skeletal muscle satellite cells in vivo     

Tomowa SAKATA  Ryuichi TATSUMI  Michiko YAMADA  Sei-Ichi SHIRATSUCHI  Shinpei OKAMOTO  Wataru MIZUNOYA  Akihito HATTORI  Yoshihide IKEUCHI 《Animal Science Journal》2006,77(5):518-525

We have shown in vitro that mechanical stretch triggers activation of quiescent satellite cells of skeletal muscle to enter the cell cycle through an intracellular cascade of events including nitric oxide (NO) synthesis that results in the release of hepatocyte growth factor (HGF) from its extracellular association and its subsequent presentation to signaling receptors. In order to explore the activation mechanism in vivo, stretch experiments were conducted in the living animal using our suspension model developed. This system used the weight of the hind portion of rats to stretch the inside muscles of the left hind limb suspended for a period of 0.5–2.0 h. At the end of the stretch period, the rats received an intraperitoneal injection of bromodeoxyuridine followed by immunocytochemistry for its incorporation as an index of satellite cell activation in vivo. Depending on the period of stretch, bromodeoxyuridine labeling was increased significantly over the contralateral unstretched leg or control muscle from untreated rats. A stretched muscle extract prepared from the 2 h stretched tissue by incubating it in PBS, showed the active form of HGF as revealed by immunoblotting and it could stimulate the activation of unstretched satellite cells. Also, administering NO synthase inhibitor L‐NAME prior to muscle stretch abolished the stretch activation of satellite cells. Therefore, the results from these experiments demonstrate that stretching muscle triggers NO synthesis and HGF release, which could activate satellite cells in vivo.  相似文献   

Development of wooden portal frame structures with improved columns     

Masahiro Noguchi  Shinjiro Takino  Kohei Komatsu 《Journal of Wood Science》2006,52(1):51-57

In Japan, the lifetime cycle of most housing lasts around 20–30 years. A governing factor in this respect is poor durability due to old-fashioned use of the house. As a solution of this problem, houses can be built with a skeleton structure that allows free partition of spaces by future owners. To develop the skeleton structure effectively, multistory frames with spans of 6 to 10 m are required. For this reason, attention has been focused on the behavior of multistory timber frame structures. In this article, two types of wooden portal frame structures are proposed. Both structures have improved vertical columns with short horizontal members glued in. The aim of this study was to investigate structurally effective solutions with these types of columns. The first type of the new structure changed the location of the moment-transmitting ductile connection with the improved columns. The second type of structure used an extended panel zone. Nine portal frame specimens were tested. The stiffness values were improved by around 1.7 and 3.5 times when compared with the control, and the strength was improved by around 1.25 and 1.45 times.  相似文献   

Dynamic excitation and static loading tests of glulam lattice floor     

Masaki?HaradaEmail author  Kohei?Komatsu  Tomoyuki?Hayashi  Masahiko?Karube 《Journal of Wood Science》2004,50(5):450-454

A wooden lattice floor with high stiffness and damping capacity has been developed to solve noise problems in wooden apartment houses. The lattice floor consisted of Douglas fir glulam beams with inserted steel plate joints and drift pins. To examine the structural performance of the floor, dynamic excitation and static loading tests were conducted on the full size floor. The first and second order resonance frequencies of the floor were 13.5Hz and 27.0Hz, respectively. These frequencies are similar to the peak frequency of a conventional wooden floor and the combined floor fabricated from glued laminated timber and iron. The maximum static load of the floor was 127kN. The apparent flexural rigidity was less than half the value of several floors studied in the past. However, it is considered that the stiffness is improved by constructing panels and this floor has almost equivalent performance. Relative deflection was not affected by the loading history.Part of this study was presented at the International Wood Engineering Conference, New Orleans, October 1996.  相似文献   

On mechanical behavior of traditional timber shear wall in Taiwan I: background and theory derivation   总被引：1，自引：0，他引：1  

Wen-Shao Chang  Kohei Komatsu  Min-Fu Hsu  Wei-Jye Chen 《Journal of Wood Science》2007,53(1):17-23

The objectives of this study were to explore the mechanical behavior of traditional timber shear walls in Taiwan and to propose a theoretical model to predict their lateral force resistance. An extensive field investigation was conducted, and the dimensions, tectonic detail, and materials used were recorded. The data collected were used as the reference for theoretical derivation and experimental design. In the theoretical model, the moment resistance of entire shear walls was derived from the contributions of the moment-resisting capacity supplied not only by embedment and friction action between board units and beams but also the dowel action of bamboo nails. Timber shear walls with various geometric conditions and material properties are considered. The theoretical model demonstrated in this study can be used to predict the mechanical behavior of timber shear walls and will be verified by experiments in our next article.  相似文献