1,630 research outputs found

    Temperature Effects on Development of Three Cereal Aphid Parasitoids (Hymenoptera: Aphidiidae)

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    Temperature is an important climatological variable that influences the biology and ecology of insects. Poor climatic adaptation can limit the effectiveness of parasitic insects in biological control. Two exotic parasites (Syrian Diaeretiella rapae (M\u27Intosh) and Argentinean Aphidius colemani Viereck) imported for biological control of the Russian wheat aphid, Diuraphis noxia (Mordvilko), and one native parasite (Diaeretiella rapae) were reared in growth chambers in three fluctuating temperature regimes with average daily temperatures of 12, 18, and 24°C. Estimates of temperature thresholds for immature development were 3.3, 3.5, and 2.8°C, for Oklahoman D. rapae, Syrian D. rapae, and A. colemani, respectively. Estimates of thermal require- ments for development from egg to adult were 297, 278, and 301 degree-days for the three parasitoids. Dry weights of adults reared in different fluctuating temperature regimes did not differ significantly among sexes, but adults from regimes with low average temperatures of 12 and 18°C had significantly greater weights than those reared in a regime with an average temperature of 24°C. Results suggest that developmental response to temperature will not limit the effectiveness of the exotic parasites in biological control

    Plankton community composition, organic carbon and thorium-234 particle size distributions, and particle export in the Sargasso Sea

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    Measurements of plankton community composition (eight planktonic groups), particle size-fractionated (10, 20, 53, 70, and 100-μm Nitex screens) distributions of organic carbon (OC) and 234Th, and particle export of OC and 234Th are reported over a seasonal cycle (2006–2007) from the Bermuda Atlantic Time-Series (BATS) site. Results indicate a convergence of the particle size distributions of OC and 234Th during the winter-spring bloom period (January–March, 2007). The observed convergence of these particle size distributions is directly correlated to the depth-integrated abundance of autotrophic pico-eukaryotes (r = 0.97, P \u3c 0.05) and, to a lesser extent, Synechococcus (r = 0.85, P \u3c 0.14). In addition, there are positive correlations between the sediment trap flux of OC and 234Th at 150 m and the depth-integrated abundance of pico-eukaryotes (r = 0.94, P \u3c 0.06 for OC, and r = 0.98, P \u3c 0.05 for 234Th) and Synechococcus (r = 0.95, P \u3c 0.05 for OC, and r = 0.94, P \u3c 0.06 for 234Th). An implication of these observations and recent modeling studies (Richardson and Jackson, 2007) is that, although small in size, pico-plankton may influence large particle export from the surface waters of the subtropical Atlantic

    Nurses’ Knowledge and Attitudes toward Implementation of Electronic Medical Records

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    With the growth of Faith Community Nursing (FCN), one topic that needs further exploration is documentation. This includes the use of electronic medical records (EMRs). Nurses play a vital role in the planning and implementation of EMRs in the acute care setting and will also play a key role in Faith Community Nursing Programs that stand alone or partner with a health care agency. Individual computer expertise and/or attitude and knowledge of EMRs could be important in the successful implementation. Researchers utilized a modified version of the EMR questionnaire designed by Beiter and colleagues to examine nurses’ knowledge and attitudes regarding EMRs. Findings indicated as age increased, the level of experience regarding EMRs decreased. No difference was noted between the computer skills of RNs with an ADN and RNs with a BSN degree, but LPNs rated themselves as having higher computer skills than RNs. No statistical significance was noted regarding thoughts on saving time and reducing cost and other variables. Licensed practical nurses, more than RNs, indicated believing that EMRs have a positive effect on nurse-patient relationships. As implementation of EMRs occurs, plans for more training might be needed for certain groups of employees

    Quercetin as an Emerging Anti-Melanoma Agent: A Four-Focus Area Therapeutic Development Strategy

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    Replacing current refractory treatments for melanoma with new prevention and therapeutic approaches is crucial in order to successfully treat this aggressive cancer form. Melanoma develops from neural crest cells, which express tyrosinase -- a key enzyme in the pigmentation pathway. The tyrosinase enzyme is highly active in melanoma cells and metabolizes polyphenolic compounds; tyrosinase expression thus makes a feasible a target for polyphenol-based therapies. For example, quercetin (3,3′,4′,5,7-pentahydroxyflavone) is a highly ubiquitous and well-classified dietary polyphenol found in various fruits, vegetables and other plant products including onions, broccoli, kale, oranges, blueberries, apples, and tea. Quercetin has demonstrated anti-proliferative and pro-apoptotic activity in various cancer cell types. Quercetin is readily metabolized by tyrosinase into various compounds that promote anti-cancer activity; additionally, given that tyrosinase expression increases during tumorigenesis, and its activity is associated with pigmentation changes in both early- and late-stage melanocytic lesions, it suggests that quercetin can be used to target melanoma. In this review we explore the potential of Quercetin as an anti-melanoma agent utilizing and extrapolating on evidence from previous in vitro studies in various human malignant cell lines and propose a four-focus area strategy to develop quercetin as a targeted anti-melanoma compound for use as either a preventative or therapeutic agent. The four areas of focus include utilizing quercetin to i) modulate cellular bioreduction potential and associated signaling cascades, ii) affect transcription of relevant genes, iii) regulate epigenetic processes, and iv) develop effective combination therapies and delivery modalities/protocols. In general, quercetin could be used to exploit tyrosinase activity to prevent, and/or treat, melanoma with minimal additional side effects

    Self-Screening Hawking Atmosphere in the Presence of a Bulk Viscosity

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    The recent theory of 't Hooft [ Nucl. Phys. Suppl. {\bf 68}, 174 (1998)] models the black hole as a system endowed with an envelope of matter that obeys an equation of state in the form p=(γ1)ρ p=(\gamma -1)\rho, and acts as a source in Einstein's equations. The present paper generalizes the 't Hooft theory so as to take into account a bulk viscosity ζ\zeta in the fluid. It is shown that even a slight positive value of ζ\zeta will suffice to yield complete agreement with the Hawking formula for the entropy of the black hole, if the value of the constant γ\gamma takes a value that is slightly less than 4/3. The value γ=4/3\gamma=4/3 corresponds to a radiation fluid.Comment: 12 pages, LaTeX, no figures, minor extensions of the discussion. To appear in PR
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