85 research outputs found

    Third-order Perturbation Theory With Non-linear Pressure

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    We calculate the non-linear matter power spectrum using the 3rd-order perturbation theory without ignoring the pressure gradient term. We consider a semi-realistic system consisting of two matter components with and without pressure, and both are expanded into the 3rd order in perturbations in a self-consistent manner, for the first time. While the pressured component may be identified with baryons or neutrinos, in this paper we mainly explore the physics of the non-linear pressure effect using a toy model in which the Jeans length does not depend on time, i.e., the sound speed decreases as 1/a^{1/2}, where a is the scale factor. The linear analysis shows that the power spectrum below the so-called filtering scale is suppressed relative to the power spectrum of the cold dark matter. Our non-linear calculation shows that the actual filtering scale for a given sound speed is smaller than the linear filtering scale by a factor depending on the redshift and the Jeans length. A ~40% change is common, and our results suggest that, when applied to baryons, the temperature of the Inter-galactic Medium inferred from the filtering scale observed in the flux power spectrum of Lyman-alpha forests would be underestimated by a factor of two, if one used the linear filtering scale to interpret the data. The filtering mass, which is proportional to the filtering scale cubed, can also be significantly smaller than the linear theory prediction especially at low redshift, where the actual filtering mass can be smaller than the linear prediction by a factor of three. Finally, when applied to neutrinos, we find that neutrino perturbations deviate significantly from linear perturbations even below the free-streaming scales, and thus neutrinos cannot be treated as linear perturbations.Comment: 17 pages, 5 figures, submitted to Ap

    Monthly minodronate inhibits bone resorption to a greater extent than does monthly risedronate

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    AbstractAs a bisphosphonate, minodronate (MIN) is one of the strongest inhibitors of bone resorption. However, there have been no reports directly comparing the antiresorptive effects of monthly MIN with those of monthly risedronate (RIS). We enrolled 30 cases of osteoporosis (OP; 16 in the MIN group [mean age: 68.2 years] and 14 in the RIS group [mean age: 68.1 years]) to investigate the early effects of treatment by monthly MIN or RIS over a 4-month period using bone turnover marker values. Only female patients were enrolled to avoid gender bias. Urinary cross-linked N-telopeptide of type I collagen (NTX) before treatment and at 1, 2, and 4 months of therapy, as well as serum bone alkaline phosphatase and alkaline phosphatase before treatment and at 4 months afterwards, were evaluated. All bone turnover marker values were significantly decreased at 4 months in both groups. The changes in urinary NTX at the study end point for RIS and MIN were −30.1% and −63.1%, respectively. From 2 months of treatment, the antiresorptive effects on urinary NTX by MIN were significantly higher than those by RIS, indicating that MIN more immediately and strongly inhibited bone absorption. Thus, monthly MIN seems to suppress bone resorption faster and more strongly than RIS in OP treatment

    Extracting Angular Diameter Distance and Expansion Rate of the Universe from Two-dimensional Galaxy Power Spectrum at High Redshifts: Baryon Acoustic Oscillation Fitting versus Full Modeling

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    We present a method for extracting the angular diameter distances, DAD_A, and the expansion rates, HH, of the universe from the {\it two-dimensional} Baryon Acoustic Oscillations (BAO) in the galaxy power spectrum. Our method builds upon the existing algorithm called the "fit-and-extract" (FITEX) method, which allows one to extract only DA2/HD_A^2/H from a spherically averaged one-dimensional power spectrum. We develop the FITEX-2d method, an extension of the FITEX method, to include the two-dimensional information, which allows us to extract DAD_A and HH simultaneously. We test the FITEX-2d method using the Millennium Simulation as well as simplified Monte Carlo simulations with a bigger volume. The BAOs, however, contain only a limited amount of information. We show that the full modeling, including the overall shape of the power spectrum, yields much better determinations of DAD_A and HH, hence the dark energy equation of state parameters such as w0w_0 and waw_a, than the BAO-only analysis by more than a factor of two, provided that non-linear effects are under control.Comment: 14 pages, 8 figures. (v2) Detailed study on the effects of marginalization over the amplitude, redshift space distortion, and the shape of the primordial power spectrum is added. The Fisher matrix code is publicly available at http://gyudon.as.utexas.edu/~komatsu/CRL/index.html The details of the code are presented in Appendi

    Expressions of Vascular Endothelial Growth Factor (VEGF)-D and VEGF Receptor-3 in Colorectal Cancer: Relationship to Lymph Node Metastasis

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    Angiogenic factors play a major role in tumor growth and metastasis. Vascular endothelial growth factor (VEGF)- D is a ligand for VEGF receptor-3 (VEGFR-3/Flt-4), which mainly expressed on the lymphatic endothelium. Recent experimental studies have shown that VEGF-D induces tumor lymphangiogenesis and promote metastatic spread of tumor cells via lymphatic vessels. However, the contribution of VEGFD to lymph node metastasis in human colorectal cancer is less understood. We therefore examined VEGF-D and VEGFR-3 expression in patients with colorectal cancer. Sections of formalin-fixed and paraffin-embedded specimens from 76 colorectal cancers were immunohistochemically stained for VEGF-D and VEGFR-3. Staining for VEGF-D was positive in the cytoplasm of tumor cells in 43 of 76 examined tumors (56.6%). Staining for VEGFR-3 was positive in endothelial cells in 38 (50.0%) tumors. Univariate analysis showed that both VEGF-D and VEGFR-3 expressions correlated significantly with lymph node metastasis, histological type and depth of tumor invasion. However, logistic regression analysis indicated that VEGF-D expression, but not that of VEGFR-3, was an independent predictor for lymph node metastasis. Our data suggest that VEGF-D plays an important role in lymph node metastasis in colorectal cancer

    Challenges of Transarticular Screw Fixation in Young Children: Report of Surgical Treatment of a 5-Year-Old Patient's Unstable Os-Odontoideum

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    Surgical procedures for atlantoaxial (C1–C2) fusion in young children are relatively uncommon. The purpose of this study was to report on a surgical treatment for a case of atlantoaxial instability caused by os-odontoideum in association with quadriparesis and respiratory paralysis in a 5-year-old girl. We present the patient's history, physical examination, and radiographic findings, describe the surgical treatment and a five year follow-up, and provide a literature review. The instability was treated by halo immobilization, followed by C1–C2 transarticular screw fixation using a computed tomography-based navigation system. At the five year follow-up, the patient had made a complete recovery with solid union. The authors conclude that C1–2 transarticular screw fixation is technically possible as in a case of atlantoaxial instability in a five-year-old child

    Elevated Expression of Poly(ADP-Ribose) Polymerase-1 is Associated with Liver Metastasis in Colorectal Cancer.

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    Activation of poly(ADP-ribose) polymerase-1 (PARP-1) and its subsequent cleavage are early markers of apoptosis. PARP-1 is associated with DNA repair and so chromosome stability, cell cycle regulation, as well as tumorigenesis. To investigate the role of PARP-1 expression in colorectal carcinoma and its metastasis of liver, we compared the expression of PARP-1 in primary colorectal cancers with (n=15) and without liver metastasis (n=17) using a semi-quantitative reverse transcription - polymerase chain reaction. We also examined the expressions of poly(ADP-ribose) (PAR) and p53 in these tumors by immunohistochemistry. A significantly higher PARP-1 mRNA expression was noted in tumors with liver metastasis than those without liver metastasis (p<0.01). Colorectal cancers positively stained for p53 exhibited significantly higher PARP-1 mRNA expression than p53-negative tumors (p<0.01). The PAR labeling index (LI) of tumors with metastasis (0.33 ツア 0.33) was not significantly different (p=0.35) from that of tumors without liver metastasis (0.38 ツア 0.19). p53-positive tumors tended to have higher PAR LI levels than p53-negative tumors (p=0.08). Our findings suggest that PARP-1 may contribute to liver metastasis due to its DNA repair activity, resulting in survival of the tumor cells with accumulation of metastaticrelated gene\u27s damages. Detailed analysis of PARP-1 may be useful in cancer research and/or cancer therapy

    Analysis of Radioactive Elements in Testes of Large Japanese Field Mice Using an Electron Probe Micro-Analyser after the Fukushima Accident

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    The Fukushima Daiichi nuclear power plant (FDNPP) accident drew global attention to the health risks of radiation exposure. The large Japanese field mice (Apodemus speciosus) are rodents endemic to, and distributed throughout, Japan. This wild rodent live in and around the ex-evacuation zone on the ground surface and/or underground. In this study, we evaluated the effect of chronic radiation exposure associated with FDNPP accident on the testes of large Japanese field mice. Morphological analysis and electron-prove X-ray microanalysis (EPMA) was undertaken on the testes. Morphological analysis of testes based on H&E staining showed that the spermatogenesis was observed normally in the breeding season of wild mice in the heavily contaminated area. However, caesium (Cs) was not detected in all testes of wild mice from FDNPP ex-evacuation zone. In conclusion, even if the testes and the process of spermatogenesis are hypersensitive to radiation, we could not detect radiation effects on the spermatogenesis and Cs in the examined large Japanese field mice testes following chronic radiation exposure associated with the FDNPP accident

    Atrazine-Induced Aromatase Expression Is SF-1 Dependent: Implications for Endocrine Disruption in Wildlife and Reproductive Cancers in Humans

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    BACKGROUND: Atrazine is a potent endocrine disruptor that increases aromatase expression in some human cancer cell lines. The mechanism involves the inhibition of phosphodiesterase and subsequent elevation of cAMP. METHODS: We compared steroidogenic factor 1 (SF-1) expression in atrazine responsive and non-responsive cell lines and transfected SF-1 into nonresponsive cell lines to assess SF-1’s role in atrazine-induced aromatase. We used a luciferase reporter driven by the SF-1–dependent aromatase promoter (ArPII) to examine activation of this promoter by atrazine and the related simazine. We mutated the SF-1 binding site to confirm the role of SF-1. We also examined effects of 55 other chemicals. Finally, we examined the ability of atrazine and simazine to bind to SF-1 and enhance SF-1 binding to ArPII. RESULTS: Atrazine-responsive adrenal carcinoma cells (H295R) expressed 54 times more SF-1 than nonresponsive ovarian granulosa KGN cells. Exogenous SF-1 conveyed atrazine-responsiveness to otherwise nonresponsive KGN and NIH/3T3 cells. Atrazine induced binding of SF-1 to chromatin and mutation of the SF-1 binding site in ArPII eliminated SF-1 binding and atrazine-responsiveness in H295R cells. Out of 55 chemicals examined, only atrazine, simazine, and benzopyrene induced luciferase via ArPII. Atrazine bound directly to SF-1, showing that atrazine is a ligand for this “orphan” receptor. CONCLUSION: The current findings are consistent with atrazine’s endocrine-disrupting effects in fish, amphibians, and reptiles; the induction of mammary and prostate cancer in laboratory rodents; and correlations between atrazine and similar reproductive cancers in humans. This study highlights the importance of atrazine as a risk factor in endocrine disruption in wildlife and reproductive cancers in laboratory rodents and humans
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