330 research outputs found
Oviposition Sites and Emergence Habitats of 13-Year Periodical Cicadas (Brood XIX) in Eastern Virginia
While much research has been done on periodical cicadas, apparently no quantitative studies have been carried out to determine the vegetational structure of periodical cicada brood emergence sites or oviposition sites. We determined large tree and small tree densities and dominance in five forest stands which experienced high densities of Brood XIX cicada emergence in 1998. Paired observations were made at one of these sites to determine whether there was a preference for egg deposition in woodland edges versus the forest interior. A list was compiled of all the tree species which exhibited evidence of egg deposition. We found that the canopies of emergence sites can be dominated by loblolly pine (Pinus taeda), oaks (Quercus spp.), sweetgum (Liquidambar styraciflua), hickories (Carya spp.), and beech (Fagus grandifolia), with red maple (Acer rubrum) or holly (Ilex opaca) important in the understory. The abundance of loblolly pine, the only common species in which no egg deposition was found, suggests that 13 years earlier, periodical cicadas found a sufficient number of other tree species in which to deposit their eggs. This also suggests that the roots of pine trees might be capable of sustaining the cicada nymphs. Brood XIX cicadas showed a significant preference for depositing their eggs on twigs on forest edges rather than depositing on shaded twigs in the forest interior
Potential of white garlic powder (Allium sativum L.) to modify in vitro ruminal fermentation
The current study aimed to evaluate the effect of increasing doses of garlic powder (GaP) on in vitro fermentation characteristics. Two successive 24-hour incubations were run, and gas production was measured at the end of each incubation period. Liquid samplings for each dose were reserved to determine ammonia nitrogen (NH3-N) and true organic matter degradability (TOMD). Partitioning factor (PF) was estimated as the ratio between TOMD and the gas produced at 24 hours of incubation. Microbial biomass (MBM) was estimated on the bases of truly degraded substrate and PF. Results showed that gas production increased (P <0.001) with the addition of 32 and 64 mg GaP. An increase (P <0.0001) in NH3-N concentration was recorded with 4 mg and 8 mg GaP compared with control, whereas adding 32 and 64 mg resulted in a NH3-N concentration equivalent to control (averaged 39.25 mg/100 ml). The propionate (C3) increased with doses and the highest proportion was noted with the addition of 8 mg GaP (P <0.001). The TOMD was similar for all the doses except for 64 mg GaP, where a slight but significant (P <0.001) increase was noted (77.7%). GaP did not affect PF and MBM values until the dose of 64 mg. It was concluded that GaP added to a ration composed of 50% roughages and 50% concentrate did not result in drastic modifications of in vitro rumen fermentation parameters, except at the highest dose (64 mg), where an increase of gas production, TODM, PF and MBM were noted.Keywords: Ammonia-nitogen, garlic powder; gas production, microbial biomass, propionate, shee
Numerical Modeling Of Electron’s Trajectories In Cold Plasma By PIC Method
This study is a contribution to the modeling of plasma discharges. The numerical model proposed is particle type, applied to argon plasma generated by a continuous discharge. A microscopic particle model is used for solving the Boltzmann equation by considering a finite number of particles to represent the charged species. The study of the electrical behavior of plasma is performed using a PIC (Particle-In-Cell) model whitch is well suited for low-pressure no-collision plasmas. This model provides the plasma characteristics (potential, charge densities). The principle of the PIC method is based on sampling (mesh) in a 1D of the space of the reactor between two flat and parallel electrodes in which particles move under the action of electric field (applied). This method makes it possible to determine the values of electric fields (steady state and time) at every point of contact for any interpolation from the numerical values obtained by the method of finite differences.This study is a contribution to the modeling of plasma discharges. The numerical model proposed is particle type, applied to argon plasma generated by a continuous discharge. A microscopic particle model is used for solving the Boltzmann equation by considering a finite number of particles to represent the charged species. The study of the electrical behavior of plasma is performed using a PIC (Particle-In-Cell) model whitch is well suited for low-pressure no-collision plasmas. This model provides the plasma characteristics (potential, charge densities). The principle of the PIC method is based on sampling (mesh) in a 1D of the space of the reactor between two flat and parallel electrodes in which particles move under the action of electric field (applied). This method makes it possible to determine the values of electric fields (steady state and time) at every point of contact for any interpolation from the numerical values obtained by the method of finite differences
Development Of A One Dimensional Fluid Model, Application To Electropositive And Electronegative Gases In DC Discharge
The objective of the work presented in this paper is to develop a numerical calculation program which simulates the behavior of charged species in deposition reactor by cold plasma in DC glow discharge. After applying some simplifying assumptions, we developed a model of fluid type in MATLAB using the numerical method of finite differences. We applied the model to simulate the plasma in the case of an electropositive (He) and an electronegative (SF6) gases in terms of spatial distribution of charged particles, electric field and electric potential between electrodes space.The objective of the work presented in this paper is to develop a numerical calculation program which simulates the behavior of charged species in deposition reactor by cold plasma in DC glow discharge. After applying some simplifying assumptions, we developed a model of fluid type in MATLAB using the numerical method of finite differences. We applied the model to simulate the plasma in the case of an electropositive (He) and an electronegative (SF6) gases in terms of spatial distribution of charged particles, electric field and electric potential between electrodes space
Experimental investigation on the concentration and voltage effects on the characteristics of deposited magnesium–lanthanum powder
International audiencePhone: +33 248 484 065 Highlights x We synthetize Mg-La powders by means of an electrodeposition process. x We characterize Mg-La powders using EDS, SEM, XRD and FTIR techniques
Estudio comparativo de la acción antimicrobiana de diversos fondos cavitarios empleados en Odontología conservadora
La existencia de diversos fondos cavitarios, nos ha conducido a la comparación de su acción inhibidora del crecimiento microbiano. Para ellos se han tenido en cuenta los siguientes fondos cavitarios: Life, Dycal. 11, Calcipulpe, Hidróxido cálcico puro y Cavitec; habiendo testado las siguientes especies bacterianas: Veillonella parvula, Bacteroides'fragilis, Peptococcus s.p., Staphylococcus aureus y Streptococcus B hemolítico. Los resultados obtenidos en esta investigación demuestran el mayor efecto antimicrobiano de los fondos comerciales con base de hidróxido cálcico sobre el Hidróxido cálcico puro y el fondo cavitario con base de óxido de zinc y eugenol (Cavitec)
Carbapenemase-producing Acinetobacter baumannii in two university hospitals in Algeria
International audienc
Eficacia de la esterilización de instrumental endodóncico estandarizado por diversos métodos
En este estudio se han determinado los valores mínimos de la relación tiempo-temperatura eficaces para la esterilización de limas k contaminadas por Bacillus subtilis, por diferentes métodos de esterilización. La esterilización con calor seco y óxido de etileno fue absoluta, por el contrario se observaron resultados diversos con calor húmedo
Undernutrition is associated with increased financial losses in hospitals.
Undernutrition is associated with increased hospital costs. Whether these increased costs are totally compensated by third payer systems has not been assessed. We aimed to assess the differences between actual and reimbursed hospital costs according to presence/absence of nutritional risk, defined by a Nutritional risk screening-2002 (NRS-2002) score ≥3.
Retrospective study. Administrative data for years 2013 and 2014 of the department of internal medicine of the Lausanne university hospital. The data included total and specific costs (i.e. clinical biology, treatments, pathology). Reimbursed costs were based on the Swiss Diagnosis Related Group (DRG) system.
2200 admissions with NRS-2002 data were included (mean age 76 years, 53.9% women), 1398 (63.6%) of which were considered nutritionally 'at-risk'. After multivariate adjustment, patients nutritionally 'at-risk' had higher costs (multivariate-adjusted difference ± standard error: 34,206 ± 1246 vs. 22,214 ± 1666 CHF, p < 0.001) and higher reimbursements (26,376 ± 1105 vs. 17,783 ± 1477 CHF, p < 0.001). Still, the latter failed to cover the costs, leading to a deficit between costs and reimbursements of 7831 ± 660 CHF in patients 'at-risk' vs. 4431 ± 881 in patients 'not at-risk' (p < 0.003). Being nutritionally 'at-risk' also led to a lower likelihood of complete coverage of costs: multivariate-adjusted odds ratio and 95% confidence interval 0.77 (0.62-0.97). Patients 'at-risk' had lower percentage of total costs in medical interventions, food, imaging and "other", but the absolute differences were less than 2%.
Hospital costs of patients nutritionally 'at-risk' are less well reimbursed than of patients 'not at-risk'. Better reporting of undernutrition in medical records and better reimbursement of undernourished patients is needed
Rapid Independent Trait Evolution despite a Strong Pleiotropic Genetic Correlation
This is the publisher's version. It can also be found here:http://dx.doi.org/10.1086/661907Genetic correlations are the most commonly studied of all potential constraints on adaptive evolution. We present a comprehensive test of constraints caused by genetic correlation, comparing empirical results to predictions from theory. The additive genetic correlation between the filament and the corolla tube in wild radish flowers is very high in magnitude, is estimated with good precision, and is caused by pleiotropy. Thus, evolutionary changes in the relative lengths of these two traits should be constrained. Still, artificial selection produced rapid evolution of these traits in opposite directions, so that in one replicate relative to controls, the difference between them increased by six standard deviations in only nine generations. This would result in a 54% increase in relative fitness on the basis of a previous estimate of natural selection in this population, and it would produce the phenotypes found in the most extreme species in the family Brassicaceae in less than 100 generations. These responses were within theoretical expectations and were much slower than if the genetic correlation was zero; thus, there was evidence for constraint. These results, coupled with comparable results from other species, show that evolution can be rapid despite the constraints caused by genetic correlations
- …