345 research outputs found
Differential photosynthetic adaptation between size-classes of Spruce and Fir juveniles help to explain the co-existence of the two species.
Background/Question/Methods 
_Abies sachalinensis_ (Sakhalin Fir) and _Picea glehnii_ (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change. 
Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of these species, on different developmental stages. 
The study is taking place on a sub-boreal forest plot in north Japan (N 44º 19’, E 142º 15’). Twenty shade-growing individuals of both species were divided into two height classes: seedlings, if height < 50cm; and saplings, if height > 100cm. The canopy coverage over each individual was assessed by analyzing hemispherical photography and average light incidence. Leaf pigments are being analyzed by chromatography. Light response curves and chlorophyll fluorescence are being measured seasonally, except in winter. Results are analyzed through General Linear Models. The study period was from spring 2009 to summer 2010. 
Results/Conclusions 
Results show an inversion of the photosynthetic adaptation between seedlings and saplings, and also between species. _Picea_ seedlings and _Abies_ saplings have greater total chlorophyll content and higher photosynthetic rates than _Picea_ saplings and _Abies_ seedlings. As a consequence, the superior competitor between similar sized individuals of both species appears to change between size-classes, with _Abies_ presenting higher photosynthetic rates at the sapling class and _Picea_ at the seedling class. Nevertheless, no significant growth has been observed in any of the groups until now. Results also disagree with some of the previously reported photosynthetic characteristics of these species, with _Picea_ seedlings displaying more traits usually associated with shade adaptation than _Abies_ seedlings.

A Case of Syncope Induced in the Supine Position
We experienced a reproducible supine syncope followed by upper abdominal pain. A 66-year-old man was transferred to our hospital after an episode of syncope during sleep. He had a history of acute pancreatitis, diabetes, hypertension, and dyslipidemia, but no history of presyncopal attack. One night, his wife noticed he was snoring abnormally in bed, and he did not respond to her voice until after she tried many times to wake him. The same attack was reproduced three times in the same situation. One of the attacks was recorded under a continuous ECG and radial tonometry. In this case, a presyncopal attack and a sense of ill-feeling were provoked by the patient lying in a prolonged supine position. He was eventually diagnosed as metastatic liver tumor 5 months after the first attack. Because few cases of syncopal attack have been reported in the supine position, its underlying mechanisms deserve consideration
An Assessment of Radioactivity Levels of 210Pb and 40K in Tobacco and Radiation Exposure from Smoking
No research has been conducted on the radiation influence of tobacco on the alimentary system, although there have been some previous works on the respiratory system. In this study, the radioactive concentrations of 210Pb and 40K in a cigarette sample were first measured. The transfer factors of the nuclides from tobacco into smoke and solution (saliva and/or alcohol) were then examined. Moreover, the radiation doses from smoke inhalation were also evaluated. The radioactive concentrations of 210Pb and 40K in the cigarette tobacco were 0.01 and 0.3 Bq/cigarette. Since this 210Pb activity and the 210Po activity previously reported for the same sample were comparable, it can be concluded that there was a radioactive equilibrium between the 2 nuclides. The observed transfer factor of 210Pb (12%) into smoke was almost the same as that of 40K (15%), whereas the reported value for 210Po (60%) was significantly higher. The radiation doses due to inhalation of cigarette smoke varied from organ to organ, depending on the organotropic properties of the nuclide. For example, the kidneys, respiratory tract, and spleen showed relatively high doses from 210Pb and 210Po. The leaching rates indicated an inconsistent tendency related to solution types. This result could suggest that alcohol drinking, which is common in smokers, does not especially enhance the leaching characteristics
MEM Analysis on Electron Density Distribution of Superconductors, Pb2Sr2Y0.90Sr0.10Cu3O8, Pb2Sr2Y1-xCaxCu3O8 (x=0.25 and 0.41) and Pb2Sr2Ho0.64Ca0.36Cu3O8
H1.X with different properties from other linker histones is required for mitotic progression
AbstractWe report here the characterization of H1.X, a human histone H1 subtype. We demonstrate that H1.X accumulates in the nucleolus during interphase and is distributed at the chromosome periphery during mitosis. In addition, the results of fluorescence recovery after photobleaching indicate that the exchange of H1.X on and off chromatin is faster than that of the other H1 subtypes. Furthermore, RNA interference experiments reveal that H1.X is required for chromosome alignment and segregation. Our results suggest that H1.X has important functions in mitotic progression, which are different from those of the other H1 subtypes
岡山大学における核燃料物質の安全管理のための劣化ウランと天然ウランの鑑別について
In Japan, the Law for the Regulation of Nuclear Source Materials, Nuclear Fuel Materials and Reactors (Regulation Law) controls the nuclear fuel materials such as thorium (Th), uranium (U) and plutonium (Pu). Under the Regulation Law, all related materials and reactors are needed to register to the Government. In Okayama University, many nuclear fuel materials, mainly uranium compounds, are registered and stored in 11 departments, separately. Discrimination between depleted uranium and natural uranium is important for the observance of the Regulation Law and the safety management of the nuclear fuel materials in the Okayama University. However, the discrimination of the two kind of uranium has poorly analyzed. In this study, we analyzed several uranium compounds by using γ-ray spectrometry to determine whether the depleted uranium or not
Molecular characterization of the sequences of the 16S-23S rDNA internal spacer region (ISR) from isolates of Taylorella asinigenitalis
<p>Abstract</p> <p>Background</p> <p>Sequence information on the 16S-23S rDNA internal spacer region (ISR) exhibits a large degree of sequence and length variation at both the genus and species levels. A primer pair for the amplification of 16S-23S rDNA ISR generated three amplicons for each of isolates of <it>Taylorella asinigenitalis </it>(UCD-1<sup>T</sup>, UK-1 and UK-2).</p> <p>Findings</p> <p>Following TA cloning and sequencing, the three isolates of <it>T. asinigenitalis </it>were demonstrated to possess three ISR units of different lengths. Although the three corresponding ISRs (A, B and C) were identified to be identical to each other (UK-1 and UK-2 isolates), the ISRs shared approximately 95.3–98.9% nucleotide sequence similarities between the UCD-1<sup>T </sup>and UK-1/-2 isolates. A typical order of two intercistronic tRNA genes (5'-tRNA<sup>Ile</sup>-tRNA<sup>Ala</sup>-3') with the different nucleotide spacers [44 through 51 base pairs (bp)] in length was identified among the isolates. The consensus sequences of the antiterminators of <b>boxB </b>and <b>boxA </b>were also identified in all ISRs. Thus, three ISRs were identified for each isolate, and therefore, at least three distinctly different ribosomal RNA operons were suggested to occur in the genome of <it>T. asinigenitalis</it>. This was also confirmed by Southern hybridization procedure.</p> <p>Conclusion</p> <p>The present study represents a dendrogram constructed based on the nucleotide sequence data of 16S-23S rDNA ISR for <it>T. asinigenitalis</it>, which may aid in the phylogenetic positioning of <it>T. asinigenitalis </it>within the genus <it>Taylorella</it>, and in the molecular discrimination of <it>T. asinigenitalis</it>.</p
Distinct Osteogenic Potentials of BMP-2 and FGF-2 in Extramedullary and Medullary Microenvironments
Bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2) have been regarded as the major cytokines promoting bone formation, however, several studies have reported unexpected results with failure of bone formation or bone resorption of these growth factors. In this study, BMP-2 and FGF-2 adsorbed into atellocollagen sponges were transplanted into bone defects in the bone marrow-scarce calvaria (extramedullary environment) and bone marrow-abundant femur (medullary environment) for analysis of their in vivo effects not only on osteoblasts, osteoclasts but also on bone marrow cells. The results showed that BMP-2 induced high bone formation in the bone marrow-scarce calvaria, but induced bone resorption in the bone marrow-abundant femurs. On the other hand, FGF-2 showed opposite effects compared to those of BMP-2. Analysis of cellular dynamics revealed numerous osteoblasts and osteoclasts present in the newly-formed bone induced by BMP-2 in calvaria, but none were seen in either control or FGF-2-transplanted groups. On the other hand, in the femur, numerous osteoclasts were observed in the vicinity of the BMP-2 pellet, while a great number of osteoblasts were seen near the FGF-2 pellets or in the control group. Of note, FCM analysis showed that both BMP-2 and FGF-2 administrated in the femur did not significantly affect the hematopoietic cell population, indicating a relatively safe application of the two growth factors. Together, these results indicate that BMP-2 could be suitable for application in extramedullary bone regeneration, whereas FGF-2 could be suitable for application in medullary bone regeneration
BMP-2/beta-TCP Local Delivery for Bone Regeneration in MRONJ-Like Mouse Model
Medication-related osteonecrosis of the jaw (MRONJ) is a severe pathological condition associated mainly with the long-term administration of bone resorption inhibitors, which are known to induce suppression of osteoclast activity and bone remodeling. Bone Morphogenetic Protein (BMP)-2 is known to be a strong inducer of bone remodeling, by directly regulating osteoblast differentiation and osteoclast activity. This study aimed to evaluate the effects of BMP-2 adsorbed onto beta-tricalcium phosphate (beta-TCP), which is an osteoinductive bioceramic material and allows space retention, on the prevention and treatment of MRONJ in mice. Tooth extraction was performed after 3 weeks of zoledronate (ZA) and cyclophosphamide (CY) administration. For prevention studies, BMP-2/beta-TCP was transplanted immediately after tooth extraction, and the mice were administered ZA and CY for an additional 4 weeks. The results showed that while the tooth extraction socket was mainly filled with a sparse tissue in the control group, bone formation was observed at the apex of the tooth extraction socket and was filled with a dense connective tissue rich in cellular components in the BMP-2/beta-TCP transplanted group. For treatment studies, BMP-2/beta-TCP was transplanted 2 weeks after tooth extraction, and bone formation was followed up for the subsequent 4 weeks under ZA and CY suspension. The results showed that although the tooth extraction socket was mainly filled with soft tissue in the control group, transplantation of BMP-2/beta-TCP could significantly accelerate bone formation, as shown by immunohistochemical analysis for osteopontin, and reduce the bone necrosis in tooth extraction sockets. These data suggest that the combination of BMP-2/beta-TCP could become a suitable therapy for the management of MRONJ
- …