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781.
Long-lived volcanism on the lunar farside revealed by SELENE Terrain Camera   总被引:2,自引:0,他引:2  
We determined model ages of mare deposits on the farside of the Moon on the basis of the crater frequency distributions in 10-meter-resolution images obtained by the Terrain Camera on SELENE (Selenological and Engineering Explorer) (Kaguya). Most mare volcanism that formed mare deposits on the lunar farside ceased at approximately 3.0 billion years ago, suggesting that mare volcanism on the Moon was markedly reduced globally during this period. However, several mare deposits at various locations on the lunar farside also show a much younger age, clustering at approximately 2.5 billion years ago. These young ages indicate that mare volcanism on the lunar farside lasted longer than was previously considered and may have occurred episodically.  相似文献   
782.
Five hundred and fourteen soil samples collected from 78 sites in Japan were analyzed for their contents of trace and ultra-trace elements. We estimated the background levels (natural abundance) of 57 elements in soils. The concentration ranges were so wide that the ratios of the highest values to the lowest values were more than 100 for all the elements, with the exception of Be, Ga, Mo, Ag, In, Sn, and Ba. While the concentrations of the first transition elements (21Sc to 30Zn in atomic numbers) were higher than the concentration of the other elements, those of lighter (3Li and 4Be) and heavier elements tended to decrease, with an increase or decrease of atomic numbers, with the apparent exception of Pb, Th, and U. Concentrations of elements with even atomic numbers were, in most of the cases, higher than the concentrations of both adjacent elements with odd atomic numbers. Frequency distribution of most of the elements was strongly positively skewed. Markedly positive correlation coefficients (r>0.9) were observed among the elements within the same group in the Periodic Table in many combinations. The dendrogram obtained by cluster analysis showed that the occurrence and distribution of the elements in soils were mostly controlled by the chemical properties of each element, rather than by the nature and properties of individual soil samples. The total contents of the elements in soils were strongly dependent on the chemical composition of the parent rocks from which respective soils were derived.  相似文献   
783.
In Nepal, mycobacterial isolates obtained from the milk and feces of buffaloes and cattle that were positive for the single intradermal cervical tuberculin (SICT) tests were genetically identified. A total of 36 mycobacterial strains were isolated from 39% of the buffaloes (14 of 36) and 34% of the cattle (11 of 32). Of the 36 strains, 13 were identified as M. bovis, and these strains were isolated from 17% of the buffaloes (6 of 36) and 16% of the cattle (5 of 32). M. bovis was isolated from both the milk and feces of one buffalo and one cattle, the milk alone of three buffaloes and three cattle, and the feces alone of two buffaloes and one cattle. These results suggest that milking buffaloes and cattle infected with M. bovis exist in Nepal. The remaining 23 strains were atypical mycobacteria. A program for the elimination of bovine tuberculosis should be implemented as soon as possible, and the public health education and proper hygienic practices may be required.  相似文献   
784.
Cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA), which appears abundantly in hypertrophic cartilage at the stage of endochondral ossification, is also detected in cerebrospinal fluid (CSF) following spinal cord injury. In this study, the localization of the CD-RAP/MIA molecule in normal tissues of the spine and brain obtained from mice, rats, dogs, cattle and horses was examined using immunohistochemistry with a specific antibody. The positive signals of CD-RAP/MIA were found at nerve cells in the spinal cords of all species and were especially strong at cerebellar Purkinje cells. The results suggested that CD-RAP/MIA included in normal cerebrospinal tissues could be a biomarker associated with tissue injuries, as the molecules might flow into the CSF.  相似文献   
785.
Five hundred and fifty fish samples from various stages in the course of distribution in Hyogo Prefecture (209 retailed in super markets, 173 obtained from fishery cooperatives at a harbor, 91 caught by trawling and 77 caught by rod fishing) were examined for contamination with Staphylococcus aureus (S. aureus). S. aureus was detected in 41 (19.6%) of the retail fish samples and 46 (26.6%) of the samples from the fishery cooperatives. No S. aureus was isolated from the live fish (91 trawled and 77 fished by rod). With regard to the retail fish, the contamination rate of processed fish (26.0%) was significantly higher than that of unprocessed fish (14.2%). For 88 samples, the efficacy of the selective medium was compared using Baird-Parker agar and mannitol salt agar supplemented with egg yolk (MSEY agar) by the direct plate and enrichment culture methods. Using the direct culture method, the S. aureus positive rate with the Baird-Parker agar (30.7%) was significantly higher (P<0.01) than that with the MSEY agar (6.8%). The enrichment culture method remarkably raised the S. aureus detection rate. Seventy-eight (85.7%) of 91 isolates belonged to the human ecovar. Sixty-two (68.1%) of the 91 isolates had some enterotoxin genes, including 44 (48.4%) with the sea gene. These data showed that the fish were contaminated with S. aureus after landing and that Baird-Parker agar had an advantage in detecting S. aureus with a direct plate culture.  相似文献   
786.
Oocyte-specific linker histone H1foo is localized in the oocyte nucleus, either diffusely or bound to chromatin, during the processes of meiotic maturation and fertilization. This expression pattern suggests that H1foo plays a key role in the control of gene expression and chromatin modification during oogenesis and early embryogenesis. To reveal the function of H1foo, we microinjected antisense morpholino oligonucleotides (MO) against H1foo into mouse germinal-vesicle stage oocytes. The rate of in vitro maturation of the antisense MO group was significantly lower than that of the control group. Eggs that failed to extrude a first polar body following injection of antisense MO arrested at metaphase I. Additionally, co-injection of in vitro synthesized H1foo mRNA along with antisense MO successfully rescued expression of H1foo and improved the in vitro maturation rate. There was no difference in the rate of parthenogenesis between the antisense MO and control groups. These results indicate that H1foo is essential for maturation of germinal vesicle-stage oocytes.  相似文献   
787.
To clarify the cellular immune system in dairy cows with inflammatory diseases after calving, the leukocyte subsets were examined in Holstein dairy cows. Twenty Holstein cows reared in one herd, were used in this study. Nine cows (Group 1) experienced onset of mastitis or puerperal fever within 2 weeks after calving, and the other eleven cows remained healthy (Group 2) after calving. The numbers of CD3(+), CD4(+) and CD8(+) cells tended to be lower in Group 1 than in Group 2 from the day of calving through week 1. These results suggested that the cows with inflammatory diseases might have experienced a decline in T cells by the day of calving, before the onset of disease.  相似文献   
788.
We performed a retrospective study of 56 dogs with Patent Ductus Arteriosus (PDA) to evaluate the indications for and efficacy of transarterial PDA coil embolization. Transarterial PDA coil embolization was conducted in 37 cases (66.1%) and surgical ligation was conducted in 16 cases (28.6%). Three cases (5.4%) were diagnosed as pulmonary hypertension and were excluded from surgical intervention. Although coil dislodgement was observed in the pulmonary artery in one case, no death occurred during coil embolization or surgical ligation. Echocardiography showed that fractional shortening decreased from 35.4 +/- 6.8% to 30.2 +/- 5.9% (P<0.05) after transarterial PDA coil embolization. Although slight residual shunts were observed in 18 cases, transarterial PDA coil embolization was effective treatment of PDA.  相似文献   
789.
The purpose of this study was to investigate the effects of sevoflurane concentration on canine visual evoked potentials with pattern stimulation (P-VEPs). Six clinically normal laboratory-beagle dogs were used. The minimum alveolar concentration (MAC) of sevoflurane was detected from all subjects by tail clamp method. The refractive power of the right eyes of all subjects was corrected to −2 diopters after skiascopy. For P-VEP recording, the recording and reference electrode were positioned at inion and nasion, respectively, and the earth electrode was positioned on the inner surface. To grasp the state of CNS suppression objectively, the bispectral index (BIS) value was used. The stimulus pattern size and distance for VEP recording were constant, 50.3 arc-min and 50 cm, respectively. P-VEPs and BIS values were recorded under sevoflurane in oxygen inhalational anesthesia at 0.5, 1.0, 1.5, 2.0, 2.5 and 2.75 sevoflurane MAC. For analysis of P-VEP, the P100 implicit time and N75-P100 amplitude were estimated. P-VEPs were detected at 0.5 to 1.5 MAC in all dogs, and disappeared at 2.0 MAC in four dogs and at 2.5 and 2.75 MAC in one dog each. The BIS value decreased with increasing sevoflurane MAC, and burst suppression began to appear from 1.5 MAC. There was no significant change in P100 implicit time and N75-P100 amplitude with any concentration of sevoflurane. At concentrations around 1.5 MAC, which are used routinely to immobilize dogs, sevoflurane showed no effect on P-VEP.  相似文献   
790.
The present study aimed to determine estrogen feedback action sites to mediate prepubertal restraint of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release in female rats. Wistar-Imamichi strain rats were ovariectomized (OVX) and received a local estradiol-17β (estradiol) or cholesterol microimplant in several brain areas, such as the medial preoptic area (mPOA), paraventricular nucleus, ventromedial nucleus and arcuate nucleus (ARC), at 20 or 35 days of age. Six days after receiving the estradiol microimplant, animals were bled to detect LH pulses at 26 or 41 days of age, representing the pre- or postpubertal period, respectively. Estradiol microimplants in the mPOA or ARC, but not in other brain regions, suppressed LH pulses in prepubertal OVX rats. Apparent LH pulses were found in the postpubertal period in all animals bearing estradiol or cholesterol implants. It is unlikely that pubertal changes in responsiveness to estrogen are due to a change in estrogen receptor (ER) expression, because the number of ERα-immunoreactive cells and mRNA levels of Esr1, Esr2 and Gpr30 in the mPOA and ARC were comparable between the pre- and postpubertal periods. In addition, kisspeptin or GnRH injection overrode estradiol-dependent prepubertal LH suppression, suggesting that estrogen inhibits the kisspeptin-GnRH cascade during the prepubertal period. Thus, estrogen-responsive neurons located in the mPOA and ARC may play key roles in estrogen-dependent prepubertal restraint of GnRH/LH secretion in female rats.  相似文献   
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