325 research outputs found
Computer simulations on the initiation and morphological difference of Japan winter and summer sprites
[1] Two‐dimensional (axisymmetric) computer simulations (electromagnetic code) have been performed to study the initiation and morphological difference (summer, carrots, and winter, columns) of sprites for simulating Japan summer and winter sprites. By changing the physical parameters of a parent lightning, we have found the following findings by looking at the spatial‐temporal distribution of reduced electric field, etc. (1) There are three important factors (the height where the charge is removed (ds), charge transfer (Q), and lightning current risetime (τ)) in the initiation of sprites and their morphological differences. (2) For the initiation of sprites, the charge transfer (Q) should exceed a certain value for possible charge heights (giving us a threshold of charge moment change (Qds) of the order of ∼120–200 C·km), with a combination of small risetime of lightning current waveform. (3) Further, the height for positive charge is much higher than that for negative charge in a typical lightning configuration, which is the essential factor in determining the morphological difference of sprites in summer and winter. Positive charges for summer are located at a much higher altitude than those in winter in Japan, which might result in carrot‐type in summer and columnar‐type in winter even for the same positive polarity. (4) A combinational effect of (Ids) and (Qds) is important for having sprites. Finally, the present computer results on the initiation of sprites for Japanese lightning have been compared extensively to the well‐documented properties of summer continental sprites and future subjects to study have been suggested
Piezoelectric Vibration Energy Harvester Using Polyvinylidene Difluoride Film Formed by Bar-Coating Method and Its Spray- Coating Method on a Three Dimensional Surface
A cantilever-type vibration energy harvester (VEH) made of polyvinylidene difluoride (PVDF) was fabricated and characterized. PVDF is one of the polymer piezoelectric materials, which is more flexible than ceramic-based piezoelectric materials such as lead zirconate titanate (PZT). The fabrication process of VEH is as follows: a PVDF film was coated on a phosphor bronze plate by bar-coating method, followed by polarization by corona discharge method. Aluminum top electrode was deposited on the PVDF film by sputtering. One end of the plate was clamped by a fixture to form a cantilever, the length of which is 25 mm. Output power P at the resonance frequency (=55 Hz) was measured as a function of load resistance R with the acceleration set at 17 m/s2. Maximum output reached 4.3 μW at R = 2.1 MΩ. This result is not inferior compared with other reported VEHs using ceramic piezoelectric material. Spray coating was carried out to form PVDF film on a 3D surface. This method is suitable for fabricating a uniform thin film on a three-dimensional (3D) surface, even if it is complicatedly curved. In this study, PVDF film was formed on a 3D helical compressing spring, and the deposition on it was successfully achieved
Estimation of Genetic Parameters, and Genetic and Environmental Effects on Progeny Carcass Traits of a Nucleus Breeding Population in Japanese Black Cattle
Genetic parameters of body weight at the start of fattening (BSF), carcass weight (CWT), subcutaneous fat thickness (SFT), rib thickness (RBT), meat quality grade (MQG), beef marbling score (BMS) and rib eye area (REA) in Japanese Black cattle were estimated. The effects of genetic and environmental factors on fattening performance and carcass quality traits of the progeny were also analyzed. The averages of BSF, CWT, SFT, RBT and REA were 189 kg, 408 kg, 24.9 mm, 69.3 mm and 47.5 cm^2, respectively. CWT was significantly affected (p<0.01) by sire, while BSF (p<0.01), CWT (p<0.01), SFT (p<0.01), RBT (p<0.01) and REA (p<0.05) were significantly affected by dam, indicating the scope of the applicability of selective breeding for improving the dam population for producing beef cattle with greater genetic ability to carcass traits. The sex of the calf had a significant (p<0.01 or p<0.05) effect on all the traits studied except REA. BSF, RBT, MQG and BMS were significantly (p<0.01) affected by the year and season of the birth of calves. The fattening farm exerted a significant influence (p<0.01) on BSF, CWT, MQG and BMS. The heritability estimates for BMS, CWT, RBT, BSF and MQG were 0.36, 0.34, 0.31, 0.26 and 0.23, respectively. Genetically, REA correlated negatively with BSF (-0.57) and SFT (-0.69), as did BMS with CWT (-0.35), SFT (-0.50) and RBT (-0.44). All the other traits correlated positively with one another
Study of hadron interactions in a lead-emulsion target
Topological and kinematical characteristics of hadron interactions have been
studied using a lead-emulsion target exposed to 2, 4 and 10 GeV/c hadron beams.
A total length of 60 m tracks was followed using a high speed automated
emulsion scanning system. A total of 318 hadron interaction vertices and their
secondary charged particle tracks were reconstructed. Measurement results of
interaction lengths, charged particle multiplicity, emission angles and momenta
of secondary charged particles are compared with a Monte Carlo simulation and
appear to be consistent. Nuclear fragments emitted from interaction vertices
were also detected by a newly developed emulsion scanning system with
wide-angle acceptance. Their emission angle distributions are in good agreement
with the simulated distributions. Probabilities of an event being associated
with at least one fragment track are found to be greater than 50% for beam
momentum GeV/c and are well reproduced by the simulation. These
experimental results validate estimation of the background due to hadron
interactions in the sample of decay candidates in the OPERA oscillation experiment.Comment: 14 pages, 11 figure
The CCR4–NOT Deadenylase Complex Maintains Adipocyte Identity
Shortening of poly(A) tails triggers mRNA degradation; hence, mRNA deadenylation regulates many biological events. In the present study, we generated mice lacking the Cnot1 gene, which encodes an essential scaffold subunit of the CCR4–NOT deadenylase complex in adipose tissues (Cnot1-AKO mice) and we examined the role of CCR4–NOT in adipocyte function. Cnot1-AKO mice showed reduced masses of white adipose tissue (WAT) and brown adipose tissue (BAT), indicating abnormal organization and function of those tissues. Indeed, Cnot1-AKO mice showed hyperinsulinemia, hyperglycemia, insulin resistance, and glucose intolerance and they could not maintain a normal body temperature during cold exposure. Muscle-like fibrous material appeared in both WAT and BAT of Cnot1-AKO mice, suggesting the acquisition of non-adipose tissue characteristics. Gene expression analysis using RNA-sequencing (RNA-seq) showed that the levels of adipose tissue-related mRNAs, including those of metabolic genes, decreased, whereas the levels of inflammatory response-related mRNAs increased. These data suggest that the CCR4–NOT complex ensures proper adipose tissue function by maintaining adipocyte-specific mRNAs at appropriate levels and by simultaneously suppressing mRNAs that would impair adipocyte function if overexpressed
Inhibition of IgE-dependent Mouse Triphasic Cutaneous Reaction by a Boiling Water Fraction Separated from Mycelium of Phellinus linteus
Phellinus linteus, a mushroom, contains constituents that exhibit potent antitumor effects through activating immune cells. Recently, anti-inflammatory and anti-allergic properties of P. linteus extracts have also been implicated. In the present study, therefore, we separated the constituents of mycelium of P. linteus into five fractions—chloroform-soluble (CF), ethyl acetate-soluble (EA), methanol-soluble (AE), water-soluble (WA) and boiling water-soluble (BW) fractions—and examined their suppressive effects on the IgE-dependent mouse triphasic cutaneous reaction. The triphasic reaction was induced in the ear of BALB/c mice passively sensitized with anti-dinitrophenol IgE by painting with 2,4-dinitrofluorobenzene 24 h later. Ear swelling appeared triphasically with peak responses at 1 h, 24 h and 8 days after the challenge. ME, WA and BW given orally at a dose of 100 mg kg(−1) significantly inhibited the first and second phase ear swelling, and BW also inhibited the third phase response. CF only inhibited the second phase. The inhibition by BW was the most potent and almost dose-dependent at doses of 30–300 mg kg(−1). BW also inhibited vascular permeability increase caused by passive cutaneous anaphylaxis and histamine, and ear swelling caused by tumor necrosis factor-α. In contrast, BW apparently potentiated the production of interleukin-4 and interferon-γ from anti-CD3-stimulated mouse splenocytes. These results indicate that BW derived from mycelium of P. linteus contains some constituents with anti-allergic as well as immunopotentiating properties
Mizoribine provides effective treatment of sequential histological change of arteritis and reduction of inflammatory cytokines and chemokines in an animal model of Kawasaki disease
<p>Abstract</p> <p>Background</p> <p>Intravenous immunoglobulin (IVIg) treatment results in an effective response from patients with acute-phase Kawasaki disease (KD), but 16.5% of them remain nonresponsive to IVIg. To address this therapeutic challenge, we tried a new therapeutic drug, mizoribine (MZR), in a mouse model of KD, which we have established using injections of <it>Candida albicans </it>water-soluble fractions (CAWS).</p> <p>Methods</p> <p>CAWS (4 mg/mouse) were injected intraperitoneally into C57BL/6N mice for 5 consecutive days. MZR or IgG was administered for 5 days. After 4 weeks, the mice were sacrificed and autopsied, the hearts were fixed in 10% neutral formalin, and plasma was taken to measure cytokines and chemokines using the Bio-Plex system.</p> <p>The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α, TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.</p> <p>Results</p> <p>The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.</p> <p>Conclusion</p> <p>MZR treatment suppressed not only the incidence, range, and degree of vasculitis, but also inflammatory cytokines and chemokines in the plasma of the KD vasculitis model mice, suggesting that MZR may be useful for treatment of KD.</p
Essential functions of the CNOT7/8 catalytic subunits of the CCR4-NOT complex in mRNA regulation and cell viability
Shortening of mRNA poly(A) tails (deadenylation) to trigger their decay is mediated mainly by the CCR4-NOT deadenylase complex. While four catalytic subunits (CNOT6, 6L 7, and 8) have been identified in the mammalian CCR4-NOT complex, their individual biological roles are not fully understood. In this study, we addressed the contribution of CNOT7/8 to viability of primary mouse embryonic fibroblasts (MEFs). We found that MEFs lacking CNOT7/8 expression [Cnot7/8-double knockout (dKO) MEFs] undergo cell death, whereas MEFs lacking CNOT6/6L expression (Cnot6/6l-dKO MEFs) remain viable. Co-immunoprecipitation analyses showed that CNOT6/6L are also absent from the CCR4-NOT complex in Cnot7/8-dKO MEFs. In contrast, either CNOT7 or CNOT8 still interacts with other subunits in the CCR4-NOT complex in Cnot6/6l-dKO MEFs. Exogenous expression of a CNOT7 mutant lacking catalytic activity in Cnot7/8-dKO MEFs cannot recover cell viability, even though CNOT6/6L exists to some extent in the CCR4-NOT complex, confirming that CNOT7/8 is essential for viability. Bulk poly(A) tail analysis revealed that mRNAs with longer poly(A) tails are more numerous in Cnot7/8-dKO MEFs than in Cnot6/6l-dKO MEFs. Consistent with elongated poly(A) tails, more mRNAs are upregulated and stabilized in Cnot7/8-dKO MEFs than in Cnot6/6l-dKO MEFs. Importantly, Cnot6/6l-dKO mice are viable and grow normally to adulthood. Taken together, the CNOT7/8 catalytic subunits are essential for deadenylation, which is necessary to maintain cell viability, whereas CNOT6/6L are not
Roles of epithelial-mesenchymal transition in squamous cell carcinoma of the temporal bone
金沢大学医薬保健研究域医学系Objectives: The authors recently demonstrated that extensive bone erosion correlated with a worse prognosis of the squamous cell carcinoma (SCC) of the temporal bone. The present objective was to investigate the expressions and the roles of epithelial-mesenchymal transition (EMT) in SCC of the temporal bone. Study Design: Retrospective patient file review and immunohistochemical study of tissues of patients with SCC of the temporal bone. Patients: The authors examined the expressions of vimentin in 16 patients with SCC of the temporal bone by immunohistochemical analysis. Results: As expected, vimentin was expressed on SCC of the temporal bone. We regard the patient who has vimentin-positive cells as EMT-positive patient because gain of vimentin is a hallmark in the EMT reported in several types of cancer. EMT positive tumors significantly correlated with extensive bone erosion, and extensive bone erosion correlated with a worse prognosis of the SCC of the temporal bone. Conclusion: The study results suggest that EMT in tumor cells becomes an important indicator of poor prognosis in SCC of the temporal bone. Copyright © 2011 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited
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