Factors affecting the dynamics of the population of Fagus crenata in the Takakuma Mountains, the southern limit of its distribution area     

Hiromi Mizunaga  Shizuo Sako  Yuri Nakao  Yoshitaka Shimono 《Journal of Forest Research》2005,10(6):481-486

The refugee population of Fagus crenata in the Takakuma Mountains, Kyushu, Japan, represents the southern limit of this species' distribution area. Because this population is the most exposed to the global warming effect, records of this population are likely to provide useful information on the response of this species to global warming. The aim of this study was to record the present status of this valuable population, enabling judgment of its sustainability. The density of successive F. crenata trees and saplings was low regardless of the coverage of dwarf bamboo. Moreover, the proportion of empty nuts observed was considerably high, suggesting to be the likely major factor limiting recruitment of saplings or successors in this population. Radial growth of F. crenata was shown to have been decreasing for the past 50 years, and there was a significantly negative correlation with the warmth index. The decreasing growth rate and poor regenerative ability caused by the high proportion of empty nuts suggest the possibility that this population will degrade further in the future, possibly being replaced by shrubs and small tree species.  相似文献   

Anisotropy and corotation of galactic cosmic rays     

Amenomori M  Ayabe S  Bi XJ  Chen D  Cui SW  Danzengluobu  Ding LK  Ding XH  Feng CF  Feng Z  Feng ZY  Gao XY  Geng QX  Guo HW  He HH  He M  Hibino K  Hotta N  Hu H  Hu HB  Huang J  Huang Q  Jia HY  Kajino F  Kasahara K  Katayose Y  Kato C  Kawata K  Labaciren  Le GM  Li AF  Li JY  Lou YQ  Lu H  Lu SL  Meng XR  Mizutani K  Mu J  Munakata K  Nagai A  Nanjo H  Nishizawa M  Ohnishi M  Ohta I  Onuma H  Ouchi T  Ozawa S  Ren JR  Saito T  Saito TY  Sakata M  Sako TK  Sasaki T  Shibata M  Shiomi A  Shirai T  Sugimoto H  Takita M  Tan YH  Tateyama N  Torii S 《Science (New York, N.Y.)》2006,314(5798):439-443

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.  相似文献   

Clinical significance of plasma mannose concentrations in healthy and diabetic dogs     

A. Mori  T. Sato  P. Lee  M. Furuuchi  H. Tazaki  K. Katayama  H. Mizutani  T. Sako  T. Arai 《Veterinary research communications》2009,33(5):439-451

Circulating levels of monosaccharides can act as a reflection of systemic glucose/ energy metabolism. Characteristic changes observed in these levels can be seen in patients with diabetes and other metabolic disorders. There have been a few reports describing the significance of mannose metabolism as an energy source under physiological and pathological conditions. However, the relationship between circulating levels of mannose and the pathophysiology of diabetes mellitus are unknown in dogs. This study examined circulating levels of mannose between healthy control and diabetic dogs and evaluated the clinical significance of mannose levels in dogs. Diabetic dogs demonstrated a higher circulating level of mannose in comparison to normal healthy control dogs. Plasma mannose was positively correlated with plasma glucose and fructosamine, respectively. Interestingly, plasma mannose levels were affected by plasma insulin levels. In the context of feeding and glucose tolerance tests, plasma mannose levels responded to changes in circulating insulin levels. Circulating plasma mannose levels decreased after feeding in both control and diabetic animals in spite of observed insulin level differences. However, when glucose tolerance tests were given, a positive correlation between mannose levels and insulin levels was observed. Therefore, plasma mannose levels obtained via glucose tolerance testing may be used as a new diagnostic method for evaluating insulin resistance or deficiency in diabetic dogs.  相似文献   

Preliminary Studies on Hepatic Carnitine Palmitoyltransferase in Dairy Cattle with or without Fatty Liver     

Mizutani H  Sako T  Toyoda Y  Kawabata T  Urumuhang N  Koyama H  Motoyoshi S 《Veterinary research communications》1999,23(8):475-480

The hepatic mitochondrial carnitine palmitoyltransferase (CPT) activity was measured by fluorimetric assay in dairy cows with or without fatty liver. CPT activities in 13 lactating cattle and in 6 non-lactating cows were 304.4±86.6 mol CoA/min per g protein and 169.3±84.8 mol CoA/min per g protein, respectively. This difference was significant (<0.05). CPT activities in early lactation (0–110 days after calving), mid-lactation (111–220 days after calving) and late lactation (over 220 days after calving) were 278.9±68.0, 312.4±124.1 and 320±59.3 mol CoA/min per g protein, respectively. There was no significant difference between the values at different stages of lactation. The CPT activity in 10 lactating cows with fatty liver unrelated to calving was 201.3±80.0 mol CoA/min per g protein. CPT activity in 10 cattle with fatty liver was significantly lower than that in normal lactating cattle. Based on these findings, clinical fatty liver unrelated to calving appears to be associated with a decrease in hepatic CPT activity.  相似文献   

Immunohistochemical evaluation of a malignant intestinal carcinoid in a dog     

Sako T  Uchida E  Okamoto M  Yamamoto E  Kagawa Y  Yoshino T  Hirayama K  Taniyama H 《Veterinary pathology》2003,40(2):212-215

An intestinal carcinoid with multiple metastases was identified in a 5-year-old male Shih Tzu with a clinical history of anemia, fatigue, anorexia, vomiting, intermittent diarrhea, intestinal bleeding, and progressive emaciation. There was a yellowish-white mass 15 mm in diameter in the anterior jejunum and white nodules consistent with metastases in many organs. Histopathologically, the mass consisted of neoplastic cells arranged in lobules, trabeculae, or closely interdigitating islands of cells. Neoplastic cells were generally polygonal with round hyperchromatic nuclei, modest amounts of eosinophilic cytoplasm, and eosinophilic cytoplasmic granules. Mitoses were common. Rosette formations of tumor cells were apparent in metastatic tumors. Immunohistochemically, tumor cells stained positive for cytokeratin 13, synaptophysin, protein gene product 9.5, neuron-specific enolase, chromogranin A, calcitonin gene-related peptide, serotonin (5-HT), and Leu-7. Serum 5-HT concentrations for this dog were increased 10-fold compared with those of normal dogs. All findings were consistent with a diagnosis of a malignant intestinal carcinoid.  相似文献   

Evaluation of tongue inspection and serology for diagnosis of Taenia solium cysticercosis in swine: usefulness of ELISA using purified glycoproteins and recombinant antigen     

Sato MO  Yamasaki H  Sako Y  Nakao M  Nakaya K  Plancarte A  Kassuku AA  Dorny P  Geerts S  Benitez-Ortiz W  Hashiguchi Y  Ito A 《Veterinary parasitology》2003,111(4):309-322

Evaluation of serology using glycoproteins (GPs) purified by preparative isoelectric focusing (pH 8.8) and recombinant chimeric antigen (RecTs) of Taenia solium was carried out using (1) blood samples on filter papers from pigs infected with different doses of eggs of T. solium in Mexico, (2) serum samples from pigs found infected naturally in Vietnam and Ecuador and (3) serum samples from pigs suspected to be infected with T. solium by tongue inspection in Tanzania. Antibody responses (IgG) were detectable in experimentally infected pigs confirmed harbouring 16 or more cysts at necropsy from 30 days after egg inoculation. One of three pigs naturally infected and harbouring 2.5 cysts/kg muscle and most of pigs harbouring=5.0 cysts/kg were also seropositive by ELISA. Although pigs may be infected with other taeniid species such as Taenia hydatigena, pigs harbouring this parasite were negative in ELISA. Approximately, 76 and 78% of sera from pigs having nodule(s) in the tongue (positive tongue inspection) were serologically positive by both ELISA and immunoblot, respectively. Furthermore, approximately 34 and 18% of sera from pigs having no nodules in the tongue (negative tongue inspection) were also seropositive by ELISA and immunoblot, respectively. ELISA using the two antigens was more sensitive than immunoblot and reliable for differentiation of pigs infected with cysticerci of T. solium from those either uninfected or infected with other taeniid species. Pigs without nodule by tongue inspection should be checked serologically in endemic areas.  相似文献   

Eimeria organisms develop in the epithelial cells of equine small intestine     

Hirayama K  Okamoto M  Sako T  Kihara K  Okai K  Taharaguchi S  Yoshino T  Taniyama H 《Veterinary pathology》2002,39(4):505-508

Histopathologic and immunohistochemical examinations were performed to determine the origin of host cells parasitized by Eimeria in the small intestines collected from five foals. Eimeria organisms at various stages (mainly microgametes and macrogametes) were frequently found in the cytoplasm of hypertrophied host cells in the lamina propria at the tips of villi of the jejunum and ileum. The cytoplasm of the host cell was immunohistochemically positive for cytokeratin AE1/AE3 and cytokeratin 13 and was negative for vimentin, desmin, alpha-smooth muscle actin, chromogranin A, neuron-specific enolase, and factor VIII. The host cells parasitized by Eimeria species had the immunostaining characteristics of epithelial cells but not of mesenchymal cells, endothelial cells of lacteals or capillaries, smooth muscle cells or neuroendocrine cells. These results suggest that the host cell of Eimeria species is possibly derived from intestinal epithelial cells and then displaced into the lamina propria of the small intestine.  相似文献   

Simultaneous determination of serum mannose and glucose concentrations in dog serum using high performance liquid chromatography     

Sato T  Katayama K  Arai T  Sako T  Tazaki H 《Research in veterinary science》2008,84(1):26-29

Serum mannose and glucose concentrations in dogs before and after eating a meal were determined simultaneously with a recently established HPLC method combined with a UV and fluorescence detection system of p-aminobenzoic acid ethyl ester (ABEE)-derivatized monosaccharides. In this newly established HPLC method, detection limits were 0.09 micromol/L for mannose and 0.04 mmol/L for glucose. Linearity of peak areas vs. amounts of mannose and glucose in the range of 0.27-320 micromol/L and 0.13-64 mmol/L were observed, respectively. The value of the glucose content measured by the HPLC method was in good agreement with that of the commonly used enzymatic method (control). Serum glucose concentrations in dogs 90 min after the meal were almost the same as those before the meal, whereas serum mannose concentrations decreased significantly after the meal. This HPLC method may be useful for determination of monosaccharides in animal blood.  相似文献   

Genomics,genetics and breeding of tropical legumes for better livelihoods of smallholder farmers     

Chris Ojiewo  Emmanuel Monyo  Haile Desmae  Ousmane Boukar  Clare Mukankusi‐Mugisha  Mahendar Thudi  Manish K. Pandey  Rachit K. Saxena  Pooran M. Gaur  Sushil K. Chaturvedi  Asnake Fikre  NPVR Ganga Rao  CV SameerKumar  Patrick Okori  Pasupuleti Janila  Jean Claude Rubyogo  Chigeza Godfree  Essegbemon Akpo  Lucky Omoigui  Stanley Nkalubo  Berhanu Fenta  Papias Binagwa  Michael Kilango  Magdalena Williams  Omari Mponda  David Okello  Mekasha Chichaybelu  Amos Miningou  Joseph Bationo  Dramane Sako  Sory Diallo  Candidus Echekwu  Muhammad Lawan Umar  Richard Oteng‐Frimpong  Haruna Mohammed  Rajeev K. Varshney 《Plant Breeding》2019,138(4):487-499

Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement.  相似文献   

Phylogenetic analysis of noxious red tide flagellates Chattonella antiqua, C. marina, C. ovata, and C. verruculosa (Raphidophyceae) based on the rRNA gene family     

Shoko Hosoi-Tanabe  Isamu Otake  Yoshihiko Sako 《Fisheries Science》2006,72(6):1200-1208

ABSTRACT:   Four species of Chattonella , which are well known to form red tides that are lethal to fish, were subjected to phylogenetic analysis on the basis of the ribosomal RNA genes (rDNA), 5.8S rDNA, 18S rDNA, 28S rDNA, and the flanking internal transcribed spacers 1 and 2 (ITS1 and ITS2). The 18S rDNA sequences of C. antiqua , C. marina , and C. ovata isolated from different regions in Japan were compared. They were found to be identical with each other in a sequence 1818 bp long. The sequences of the D1/D2 region in the 28S rDNA, 5.8S rDNA, and ITS region that are known to be more variable regions were also found to be identical. These homogeneities of the rRNA gene family revealed the extremely close relatedness of C. antiqua , C. marina , and C. ovata . The sequences of C. verruculosa were different from those of these three species , resulting in an 89.2% homology in the 18S rDNA sequences, 70.4% homology in the D1/D2 region in the 28S rDNA sequences, and an 81.5% homology in 5.8S rDNA sequences and the ITS regions. Chattonella verruculosa was grouped within a single cluster composed of Dictyochophyceae rather than the other species of Raphidophyceae.  相似文献