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Search Results: 1 - 10 of 138789 matches for " K. Tamae "
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Heavy Metal-Induced Oxidative DNA Damage in Earthworms: A Review
Takeshi Hirano,Kazuyoshi Tamae
Applied and Environmental Soil Science , 2010, DOI: 10.1155/2010/726946
Abstract: Earthworms can be used as a bio-indicator of metal contamination in soil, Earlier reports claimed the bioaccumulation of heavy metals in earthworm tissues, while the metal-induced mutagenicity reared in contaminated soils for long duration. But we examined the metal-induced mutagenicity in earthworms reared in metal containing culture beddings. In this experiment we observed the generation of 8-oxoguanine (8-oxo-Gua) in earthworms exposed to cadmium and nickel in soil. 8-oxo-Gua is a major premutagenic form of oxidative DNA damage that induces GC-to-TA point mutations, leading to carcinogenesis. 1. Introduction Molecular oxygen is essential for the survival of all aerobic organisms, and reactive oxygen species (ROS), which are byproducts of oxygen metabolism, are harmful for living organisms. Thus, oxygen is a double-edged sword. In fact, ROS are known to directly attack vital cellular components, including proteins, lipids, and nucleic acids. The oxidation of these molecules is associated with cellular dysfunction, leading to various biological responses, such as inflammation and apoptosis. Since ROS, such as superoxide radical , H2O2, and hydroxyl radical , are constantly generated in vivo as byproducts of respiration, agent metabolism, or pathophysiological conditions [1–3], it is difficult to completely prevent their harmful effects on cellular components. When ROS attack DNA, oxidized bases are frequently generated [4]. Among the various forms of oxidative DNA damage, 8-oxoguanine (7, 8-dihydro-8-oxoguanine, abbreviated as 8-oxo-Gua or 8-OH-Gua) has been most extensively investigated [5]. Since 8-oxo-Gua is premutagenic, it has been suggested to contribute to human diseases [6, 7]. On the other hand, living organisms have repair systems for oxidative DNA damage, to preserve genetic stability. Recent studies have revealed the complicated network of 8-oxo-Gua repair systems (termed as the “GO system”) [8]. However, if unrepaired oxidative DNA damage remains in DNA, then it can induce point mutations. Therefore, the ability to repair the damage is critical in terms of genetic stability. Such measurements of 8-oxo-Gua and its repair ability may open new fields in the studies of risk assessment, molecular epidemiology, and health promotion. Among the many kinds of organisms living in soil, the earthworm is a quite useful organism for the evaluation of metal contamination in soil, because significant positive correlations have been found between the metal concentrations in the earthworm and the cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)
Earthworms and Soil Pollutants
Takeshi Hirano,Kazuyoshi Tamae
Sensors , 2011, DOI: 10.3390/s111211157
Abstract: Although the toxicity of metal contaminated soils has been assessed with various bioassays, more information is needed about the biochemical responses, which may help to elucidate the mechanisms involved in metal toxicity. We previously reported that the earthworm, Eisenia fetida, accumulates cadmium in its seminal vesicles. The bio-accumulative ability of earthworms is well known, and thus the earthworm could be a useful living organism for the bio-monitoring of soil pollution. In this short review, we describe recent studies concerning the relationship between earthworms and soil pollutants, and discuss the possibility of using the earthworm as a bio-monitoring organism for soil pollution.
Small Area Predictors with Dual Shrinkage of Means and Variances
Hiromasa Tamae,Tatsuya Kubokawa
Statistics , 2015,
Abstract: The paper concerns small-area estimation in the Fay-Herriot type area-level model with random dispersions, which models the case that the sampling errors change from area to area. The resulting Bayes estimator shrinks both means and variances, but needs numerical computation to provide the estimates. In this paper, an approximated empirical Bayes (AEB) estimator with a closed form is suggested. The model parameters are estimated via the moment method, and the mean squared error of the AEB is estimated via the single parametric bootstrap method. The benchmarked estimator and a second-order unbiased estimator of the mean squared error are also derived.
Bayesian Estimators for Small Area Models Shrinking Both Means and Variances
Shonosuke Sugasawa,Hiromasa Tamae,Tatsuya Kubokawa
Statistics , 2015,
Abstract: For small area estimation of area-level data, the Fay-Herriot model is extensively used as a model based method. In the Fay Herriot model, it is conventionally assumed that the sampling variances are known whereas estimators of sampling variances are used in practice. Thus, the settings of knowing sampling variances are unrealistic and several methods are proposed to overcome this problem. In this paper, we assume the situation where the direct estimators of the sampling variances are available as well as the sample means. Using these information, we propose a Bayesian yet objective method producing shrinkage estimation of both means and variances in the Fay-Herriot model. We consider the hierarchical structure for the sampling variances and we set uniform prior on model parameters to keep objectivity of the proposed model. For validity of the posterior inference, we show under mild conditions that the posterior distribution is proper and has finite variances. We investigate the numerical performance through simulation and empirical studies.
Does Obesity without Hyperglycemia Delay Wound Healing in an Obese Mouse Model Induced by a High-Fat Diet?  [PDF]
Tamae Urai, Yukari Nakajima, Kanae Mukai, Kimi Asano, Mayumi Okuwa, Junko Sugama, Toshio Nakatani
Health (Health) , 2017, DOI: 10.4236/health.2017.912122
Abstract: It was unclear that wound healing was delayed in obesity without hyperglycemia. The purpose of this study was to compare the wound healing process between obese and non-obese mice without hyperglycemia by attaching a splint. Three-week-old male mice (C57BL/6N) were fed high-fat diets (60% of calories from fat) in the obesity group, and commercial diets in the control group for 15 weeks. Two circular (4 mm in diameter) full-thickness wounds were made on the dorsal skin. Body weights and serum leptin levels were significantly higher in the obesity group than in the control group until day 15 after wounding. Fasting blood glucose levels before wounding were lower in the obesity group than in a hyperglycemic rodent model. The macrophage infiltration into subcutaneous fat before wounding in the obesity group was negligible. The ratios of the wound area were not significantly different between the two groups. No significant differences were observed in the number of neutrophils or macrophages or new blood vessels and ratio of myofibroblasts or collagen fibers between the two groups. Our results demonstrated that cutaneous wound healing was not delayed in the obesity group without hyperglycemia and macrophage infiltration into the subcutaneous fat and with high serum leptin levels.
The Relationship between Cutaneous Wounds Made on Obese Mice or Those with Decreased Body Weight and Serum Leptin Level  [PDF]
Tamae Urai, ? Haryanto, Kanae Mukai, Tatsuhiko Matsushita, Kimi Asano, Yukari Nakajima, Mayumi Okuwa, Junko Sugama, Toshio Nakatani
Health (Health) , 2016, DOI: 10.4236/health.2016.811105
Abstract: Purpose: Not all obese people have hyperglycemia. We wondered about the healing progress in obese people without hyperglycemia. The purpose of this study is to observe the cutaneous wound healing process. Methods: Three-week-old male mice were fed high-fat diets (containing 60% fat) in the diet group, and commercial diets in the control group, ad libitum for 15 weeks. Circle-full-thickness cutaneous wounds were made on the dorsal skin of mice. From day 0 to day 15 after wounding, we analyzed wound healing process. We measured the blood concentration of leptin, and observed the distribution of leptin-positive cells in each wound. Results: Mean body weight, the areas of subcutaneous fat and visceral fat, and the weight of epididymal fat in the diet group were significantly greater than those in the control group at 15 weeks after feeding. The diet group did not feed on the diet after wounding; their body weight decreased remarkably to the level of the control group. The ratio of wound area, re-epithelialization, and collagen fibers did not differ between the diet and control groups on each day. The blood concentration of leptin in the diet group was significantly greater than that in the control group before wounding and until day 6 after wounding (day 0, 10 hour and day 1: p < 0.01, day 6: p < 0.05). Conclusion: The results show that the wound healing process is similar between obese and non-obese mice, and that the decrease in the leptin level in the obese mouse to that in the non-obese mouse may depend on the decrease of body weight of obese mouse.
PKCα Binds G3BP2 and Regulates Stress Granule Formation Following Cellular Stress
Tamae Kobayashi, Sofia Winslow, Lovisa Sunesson, Ulf Hellman, Christer Larsson
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035820
Abstract: Protein kinase C (PKC) isoforms regulate a number of processes crucial for the fate of a cell. In this study we identify previously unrecognized interaction partners of PKCα and a novel role for PKCα in the regulation of stress granule formation during cellular stress. Three RNA-binding proteins, cytoplasmic poly(A)+ binding protein (PABPC1), IGF-II mRNA binding protein 3 (IGF2BP3), and RasGAP binding protein 2 (G3BP2) all co-precipitate with PKCα. RNase treatment abolished the association with IGF2BP3 and PABPC1 whereas the PKCα-G3BP2 interaction was largely resistant to this. Furthermore, interactions between recombinant PKCα and G3BP2 indicated that the interaction is direct and PKCα can phosphorylate G3BP2 in vitro. The binding is mediated via the regulatory domain of PKCα and the C-terminal RNA-binding domain of G3BP2. Both proteins relocate to and co-localize in stress granules, but not to P-bodies, when cells are subjected to stress. Heat shock-induced stress granule assembly and phosphorylation of eIF2α are suppressed following downregulation of PKCα by siRNA. In conclusion this study identifies novel interaction partners of PKCα and a novel role for PKCα in regulation of stress granules.
Autonomia e vulnerabilidade do enfermeiro na prática da Sistematiza??o da Assistência de Enfermagem
Menezes, Silvia Regina Tamae;Priel, Margareth Rose;Pereira, Luciane Lucio;
Revista da Escola de Enfermagem da USP , 2011, DOI: 10.1590/S0080-62342011000400023
Abstract: the objective of this study was to recognize the autonomy and vulnerability of nurses in the implementation of the sistema da assistência de enfermagem (sae) nursing care system through an integrative literature review, using content analysis. a survey was conducted, and 40 articles published between 1998 and 2008 were selected based on their relevance. results showed two main categories of meaning: benefits associated to the sae practice (to patients, to the profession and to the institution) and determinants for the implementation of sae (nurse's competence, training and education, record-instruments, infrastructure and collective sharing-construction). from the integration of the two categories, the highlights were the autonomy in acting with freedom and responsibility, science-based decision-making, and being valued for their social work, as well as the vulnerability expressed by interpersonal relationships, the wear generated by professional stress and the risk inherent to the service.
Near threshold angular distributions of the $^2$H$(γ,Λ)$X reaction
B. Beckford,P. Bydzovsky,A. Chiba,D. Doi,T. Fujii,Y. Fujii,K. Futatsukawa,T. Gogami,O. Hashimoto,Y. C. Han,K. Hirose,R. Honda,K. Hosomi,T. Ishikawa,H. Kanda,M. Kaneta,Y. Kaneko,S. Kato,D. Kawama,C. Kimura,S. Kiyokawa,T. Koike,K. Maeda,K. Makabe,M. Matsubara,K. Miwa,S. Nagao,S. N. Nakamura,A. Okuyama,K. Shirotori,K. Sugihara,K. Suzuki,T. Tamae,H. Tamura,K. Tsukada,F. Yamamoto,T. O. Yamamoto,Y. Yonemoto,H. Yamazaki
Physics , 2013,
Abstract: A study of the $^2$H$({\gamma},{\Lambda})$X reaction was performed using a tagged photon beam at the Research Center for Electron Photon Science (ELPH), Tohoku University. The photoproduced $\Lambda$ was measured in the $p{\pi^{-}}$ decay channel by the upgraded Neutral Kaon Spectrometer (NKS2+). The momentum integrated differential cross section was determined as a function of the scatting angle of ${\Lambda}$ in the laboratory frame for five energy bins. Our results indicated a peak in the cross section at angles smaller than cos$\theta^{LAB}_{\Lambda}$ = $0.96$. The experimentally obtained angular distributions were compared to isobar models, Kaon-Maid (KM) and Saclay-Lyon A (SLA), in addition to the composite Regge-plus-resonance (RPR) model. Both SLA(r$K_{1}K_{\gamma}$ = $-1.4$) and RPR describe the data quite well in contrast to the KM model, which substantially under predicted the cross section at the most forward angles. With the anticipated finalized data on ${\Lambda}$ integrated and momentum dependent differential cross sections of $^2$H$({\gamma},{\Lambda})$X~\cite{Kaneta_Beckford}, we present our findings on the angular distributions in this report.
Threshold Electrodisintegration of ^3He
R. S. Hicks,A. Hotta,S. Churchwell,X. Jiang,G. A. Peterson,J. Shaw,B. Asavapibhop,M. C. Berisso,P. E. Bosted,K. Burchesky,R. A. Miskimen,S. E. Rock,I. Nakagawa,T. Tamae,T. Suda,J. Golak,R. Skibinski,H. Witala,F. Casagrande,W. Turchinetz,A. Cichocki,K. Wang,W. Glockle,H. Kamada,T. Kobayashi,A. Nogga
Physics , 2003, DOI: 10.1103/PhysRevC.67.064004
Abstract: Cross sections were measured for the near-threshold electrodisintegration of ^3He at momentum transfer values of q=2.4, 4.4, and 4.7 fm^{-1}. From these and prior measurements the transverse and longitudinal response functions R_T and R_L were deduced. Comparisons are made against previously published and new non-relativistic A=3 calculations using the best available NN potentials. In general, for q<2 fm^{-1} these calculations accurately predict the threshold electrodisintegration of ^3He. Agreement at increasing q demands consideration of two-body terms, but discrepancies still appear at the highest momentum transfers probed, perhaps due to the neglect of relativistic dynamics, or to the underestimation of high-momentum wave-function components.
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