4,384 research outputs found

    The Optimal Irradiation of Iraqi Dates Fruit by Gamma Radiation for Disinfestation Purposes

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    Fig moth E. cautella, considered the most serious pests infest dates and cause economic losses in the field and warehouses in Iraq which produces between 600-700 thousand tons of dates annually. In order to reduce this damage different pest control methods are used and fragmentation of radiation considered one of the newest and innovative way to control this Moth that attack stored dates. Dates, Zahdi variety artificially infested by eggs of Ephestia cautella .Eggs and larvae of insect were irradiated by gamma radiation with different doses between (106 - 397.5Gy) and then irradiated dates stored at 19Co, 30 and 40 days for Larvae and Eggs respectively. Fragmentation of irradiation dose of gamma were used, five periods of irradiation with three different times separating each period (5, 10, 15min). Physical and chemical properties of dates were analyzed. Results showed that the fragmentation technique is comparable with continuous irradiation and effective for eliminating the insect and keeping the dates preserved with high quality. A dose of (165Gy) and (198Gy) required for 100% hatching inability of irradiated eggs. For larvae a dose of (397.5Gy) was enough to achieve mortality of (100%), (87.50%) and (83.33) for (5, 10, 15min) separating time between each irradiation period respectively. Physical and chemical characteristics did not changed as a result of irradiation. Keywords: Ephestia cautella, stored dates, Iraq, fragmentation of irradiation

    Analytical approach to viscous fingering in a cylindrical Hele-Shaw cell

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    We report analytical results for the development of the viscous fingering instability in a cylindrical Hele-Shaw cell of radius a and thickness b. We derive a generalized version of Darcy's law in such cylindrical background, and find it recovers the usual Darcy's law for flow in flat, rectangular cells, with corrections of higher order in b/a. We focus our interest on the influence of cell's radius of curvature on the instability characteristics. Linear and slightly nonlinear flow regimes are studied through a mode-coupling analysis. Our analytical results reveal that linear growth rates and finger competition are inhibited for increasingly larger radius of curvature. The absence of tip-splitting events in cylindrical cells is also discussed.Comment: 14 pages, 3 ps figures, Revte

    Testing nonperturbative techniques in the scalar sector of the standard model

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    We discuss the current picture of the standard model's scalar sector at strong coupling. We compare the pattern observed in the scalar sector in perturbation theory up to two-loop with the nonperturbative solution obtained by a next-to-leading order 1/N expansion. In particular, we analyze two resonant Higgs scattering processes, ff -> H -> f'f' and ff -> H -> ZZ, WW. We describe the ingredients of the nonperturbative calculation, such as the tachyonic regularization, the higher order 1/N intermediate renormalization, and the numerical methods for evaluating the graphs. We discuss briefly the perspectives and usefulness of extending these nonperturbative methods to other theories

    Why the idea of framework propositions cannot contribute to an understanding of delusions

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    One of the tasks that recent philosophy of psychiatry has taken upon itself is to extend the range of understanding to some of those aspects of psychopathology that Jaspers deemed beyond its limits. Given the fundamental difficulties of offering a literal interpretation of the contents of primary delusions, a number of alternative strategies have been put forward including regarding them as abnormal versions of framework propositions described by Wittgenstein in On Certainty. But although framework propositions share some of the apparent epistemic features of primary delusions, their role in partially constituting the sense of inquiry rules out their role in helping to understand delusions

    MUSTANG: 90 GHz Science with the Green Bank Telescope

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    MUSTANG is a 90 GHz bolometer camera built for use as a facility instrument on the 100 m Robert C. Byrd Green Bank radio telescope (GBT). MUSTANG has an 8 by 8 focal plane array of transition edge sensor bolometers read out using time-domain multiplexed SQUID electronics. As a continuum instrument on a large single dish MUSTANG has a combination of high resolution (8") and good sensitivity to extended emission which make it very competitive for a wide range of galactic and extragalactic science. Commissioning finished in January 2008 and some of the first science data have been collected.Comment: 9 Pages, 5 figures, Presented at the SPIE conference on astronomical instrumentation in 200

    Bacterial Infection Increases Periodontal Bone Loss in Diabetic Rats Through Enhanced Apoptosis

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    Periodontal disease is the most common osteolytic disease in humans and is significantly increased by diabetes mellitus. We tested the hypothesis that bacterial infection induces bone loss in diabetic animals through a mechanism that involves enhanced apoptosis. Type II diabetic rats were inoculated with Aggregatibacter actinomycetemcomitans and treated with a caspase-3 inhibitor, ZDEVD-FMK, or vehicle alone. Apoptotic cells were measured with TUNEL; osteoblasts and bone area were measured in H&E sections. New bone formation was assessed by labeling with fluorescent dyes and by osteocalcin mRNA levels. Osteoclast number, eroded bone surface, and new bone formation were measured by tartrate-resistant acid phosphatase staining. Immunohistochemistry was performed with an antibody against tumor necrosis factor-α. Bacterial infection doubled the number of tumor necrosis factor-α–expressing cells and increased apoptotic cells adjacent to bone 10-fold (P \u3c 0.05). Treatment with caspase inhibitor blocked apoptosis, increased the number of osteoclasts, and eroded bone surface (P \u3c 0.05); yet, inhibition of apoptosis resulted in significantly greater net bone area because of an increase in new bone formation, osteoblast numbers, and an increase in bone coupling. Thus, bacterial infection in diabetic rats stimulates periodontitis, in part through enhanced apoptosis of osteoblastic cells that reduces osseous coupling through a caspase-3–dependent mechanism. Diabetes is a chronic inflammatory disease characterized by hyperglycemia that affects 26 million Americans.1 Diabetes has several complications, such as cardiovascular, renal, microvascular, and periodontal diseases. Periodontal disease is one of the most common forms of osteolytic bone disease and one of the most frequent complications of the diabetes.2 Recent research suggests that the relationship between periodontitis and diabetes is reciprocal.3, 4 People with diabetes are more susceptible to periodontitis, and periodontitis may affect serum glucose levels and contribute to progression of diabetes.5 Diabetes may contribute to periodontitis because of its effect on inflammation.6, 7 Despite being triggered by bacterial infection, periodontal bone loss is tied to the inflammatory host response, which leads to the generation of prostaglandins and cytokines that stimulate osteoclastogenesis and periodontal bone loss.8 Several of the detrimental aspects of periodontal disease have recently been shown to be mediated by elevated levels of tumor necrosis factor-α (TNF-α).9, 10 TNF-α is a proinflammatory cytokine produced by leukocytes and other cell types.11 Enhanced TNF-α levels have been directly linked to cellular changes in diabetic retinopathy, deficits in wound healing, and diabetes-enhanced periodontitis.12, 13, 14 Some of the detrimental effects of diabetes-enhanced TNF-α levels may be because of the induction of cell death by triggering caspase activity. Caspases are a family of cysteine proteases that can act as either initiators (caspases 2, 8, and 9) or executioners (caspases 3, 6, and 7) of apoptosis.15 Caspase-3 appears to play a central role in bacteria and lipopolysaccharide-mediated apoptosis.16, 17 In addition, it has been shown that TNF-α can stimulate the expression of several pro-apoptotic genes, many of which are regulated by the pro-apoptotic transcription factor, forkhead box-O1 (FOXO1).18 The functional role of apoptosis in pathological processes can be studied with caspase inhibitors, which are small peptides that block the activity of well-defined caspases.19 These inhibitors have been used in animal models to attenuate cell death and diminish tissue damage in ischemic conditions, sepsis, and other pathological processes.20, 21 Other studies using caspase inhibitors have shown that part of the detrimental effect of diabetes on healing after infection is the result of increased fibroblast or osteoblast apoptosis.16, 22 To understand how diabetes may affect periodontal bone loss through apoptosis, we used a caspase-3/7 inhibitor in a type 2 Goto-Kakizaki (GK) diabetic rat model of periodontal disease induced by bacterial infection. The aim of this study was to determine how apoptosis of osteoblasts contributed to periodontal bone loss by its effect on bone formation in diabetic animals

    Laminar-turbulent boundary in plane Couette flow

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    We apply the iterated edge state tracking algorithm to study the boundary between laminar and turbulent dynamics in plane Couette flow at Re=400. Perturbations that are not strong enough to become fully turbulent nor weak enough to relaminarize tend towards a hyperbolic coherent structure in state space, termed the edge state, which seems to be unique up to obvious continuous shift symmetries. The results reported here show that in cases where a fixed point has only one unstable direction, as for the lower branch solution in in plane Couette flow, the iterated edge tracking algorithm converges to this state. They also show that choice of initial state is not critical, and that essentially arbitrary initial conditions can be used to find the edge state.Comment: 4 pages, 4 figure

    A first measurement of the interaction cross section of the tau neutrino

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    The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed ντ\nu_\tau charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6×10173.6 \times 10^{17} protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed ντ\nu_\tau CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section (ν+νˉ\nu + \bar \nu), relative to the well-known νe\nu_e and νμ\nu_\mu cross sections. The ratio σ(ντ)\sigma(\nu_\tau)/σ(νe,μ)\sigma(\nu_{e,\mu}) was found to be 1.37±0.35±0.771.37\pm0.35\pm0.77. The ντ\nu_\tau CC cross section was found to be 0.72±0.24±0.36×10380.72 \pm 0.24\pm0.36 \times 10^{-38} cm2GeV1^{2}\rm{GeV}^{-1}. Both results are in agreement the Standard Model.Comment: 37 pages, 15 figure
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