Effects Of Other Modes Research Articles

Orbit-following simulations of fast-ion transport and losses due to the Alfvén eigenmode burst in the Large Helical Device

Orbit-following simulations of fast-ion transport and losses with time-dependent electromagnetic perturbations are performed to clarify the roles of Alfvén eigenmodes (AEs) and the low-frequency magnetohydrodynamic (MHD) mode observed in the kinetic-MHD hybrid simulation of AE bursts in the Large Helical Device. Fast-ion pressure profile flattening in the kinetic-MHD hybrid simulation can be reproduced by an orbit-following simulation with only the primary single AE of the time-dependent amplitude following the kinetic-MHD hybrid simulation result, while orbit-following simulations with constant AE amplitude of average level during AE burst cannot reproduce the fast-ion pressure profile flattening observed. The effects of other modes are negligible on the fast-ion pressure profile flattening. The fast-ion losses in kinetic-MHD hybrid simulation can be reproduced by an orbit-following simulation with time-dependent amplitude when the low-frequency MHD mode is considered in addition to multiple AEs. This indicates the synergetic effect of multiple AEs and the low-frequency MHD mode on fast-ion losses.

Digital technology for delivering and monitoring exercise programs for people with cystic fibrosis.

Digital technology for delivering and monitoring exercise programs for people with cystic fibrosis.

Multi-mode quasi-static excitation for systems with nonlinear joints

Finite element models can be used to model and predict the hysteresis and energy dissipation exhibited by nonlinear joints in structures. As a result of the nonlinearity, the frequency and damping of a mode is dependent on excitation amplitude, and when the modes remain uncoupled, quasi-static modal analysis has been shown to efficiently predict this behavior. However, in some cases the modes have been observed to couple such that the frequency and damping of one mode is dependent on the amplitude of other modes. To model the interactions between modes, one must integrate the dynamic equations in time, which is several orders of magnitude more expensive than quasi-static analysis. This work explores an alternative where quasi-static forces are applied in the shapes of two or more modes of vibration simultaneously, and the resulting load–displacement curves are used to deduce the effect of other modes on the effective frequency and damping of the mode in question. This methodology is demonstrated on a simple 2D cantilever beam structure with a single bolted joint which exhibits micro-slip nonlinearity over a range of vibration amplitudes. The predicted frequency and damping are compared with those extracted from a few expensive dynamic simulations of the structure, showing that the quasi-static approach produces reasonable albeit highly conservative bounds on the observed dynamics. This framework is also demonstrated on a 3D structure where dynamic simulations are infeasible.

Flexural-gravity wave dissipation under strong compression and ocean current near blocking point

Flexural-gravity wave propagation in a dissipative sea-ice under the influence of strong compressive force and ocean current is studied. The dissipation is caused by the viscous parameter introduced in the icecovered boundary condition and results in the complex dispersion relation. The complex roots are computed using the wellestablished ML method where the initial choice is made from the roots of the dispersion relation of the non-dissipative counterpart, which poses difficulties due to the wave blocking, a phenomenon where progressive wave mode collide and wave energy propagation stops. The shift in the central wavenumber of an initial Gaussian disturbance as it propagates through the dissipative compressed ice is shown following the method proposed by Muschietti and Dum (DOI:10.1063/1.860877) when the initial central wavenumber matches and/or around the blocking wavenumber. The transformation of the location and decay of maximum amplitude and group velocity over time is shown. The effects of ice thickness and in-plane compression are also demonstrated. A small decrease in central wavenumber is shown, while the group velocity increases/decreases around the primary/secondary blocking wavenumber. Further extensive research on this method is required to incorporate the effects of other modes corresponding to the frequency of the initial central wavenumber.

Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices.

Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

Buckling Behavior of Composite Plates with a Pre-central Circular Delamination Defect under in-Plane Uniaxial Compression

Delamination is one of the most common failure modes in composite structures. In the case of in-plane compressional loading, delamination of a layered flat structure can cause a local buckling in delaminated area which subsequently affects the overall stiffness of the initial structure. This leads to an early failure of the overall structure. Moreover, with an increase in load, the delaminated area may propagate in the post-buckling mode; and consequently, to predict this behavior, a combination of failure modes will be used to predict failure. In this work, the proposed analysis will predict the delamination shape and load carrying capacity of a composite laminated plate during delamination process in post-buckling mode. For this purpose, it is assumed that the composite laminate contains an initial circular delaminated (defected) area. The analysis is performed through a numerical scheme based on finite element method. Results show that in most cases, the onset of crack growth is affected by the first opening mode while it is well probable that during the delamination growth, the effects of other modes dominate the initial primary opening mode. Consequently, during progression of any delamination which may occur as a result of further loading, a jump in failure mode which is predicted in this analysis, may occur. Moreover, the induced results show that the stacking sequence of the delaminated composite plate has a significant effect on the delamination growth and the load carrying capacity of the overall structure.

A Genomic Map of the Effects of Linked Selection in Drosophila.

Natural selection at one site shapes patterns of genetic variation at linked sites. Quantifying the effects of “linked selection” on levels of genetic diversity is key to making reliable inference about demography, building a null model in scans for targets of adaptation, and learning about the dynamics of natural selection. Here, we introduce the first method that jointly infers parameters of distinct modes of linked selection, notably background selection and selective sweeps, from genome-wide diversity data, functional annotations and genetic maps. The central idea is to calculate the probability that a neutral site is polymorphic given local annotations, substitution patterns, and recombination rates. Information is then combined across sites and samples using composite likelihood in order to estimate genome-wide parameters of distinct modes of selection. In addition to parameter estimation, this approach yields a map of the expected neutral diversity levels along the genome. To illustrate the utility of our approach, we apply it to genome-wide resequencing data from 125 lines in Drosophila melanogaster and reliably predict diversity levels at the 1Mb scale. Our results corroborate estimates of a high fraction of beneficial substitutions in proteins and untranslated regions (UTR). They allow us to distinguish between the contribution of sweeps and other modes of selection around amino acid substitutions and to uncover evidence for pervasive sweeps in untranslated regions (UTRs). Our inference further suggests a substantial effect of other modes of linked selection and of adaptation in particular. More generally, we demonstrate that linked selection has had a larger effect in reducing diversity levels and increasing their variance in D. melanogaster than previously appreciated.

Dualistic distribution coefficients of elements in the system mineral-hydrothermal solution. I. Gold accumulation in pyrite

The use of trace elements (TE) as geochemical indicators is complicated by the dualism of their distribution coefficients D due to the additional (i.e., above the concentrations of an isomorphic component) incorporation of elements at structural defects of various nature (including the surface of the crystal). A pressing problem in this situation is to determine the true D values that pertain to the structural component of an admixture Dstr and evaluate effects of other modes of TE occurrence. Only upon distinguishing Dstr in the bulk coefficient Dbulk it is possible to evaluate the ore potential of fluid in terms of certain TE from the composition of a mineral containing the TE. Pyrite synthesized in solutions of variable pH at 450°C and 1 kbar (100 MPa) at fluid portions sampled in a trap is utilized to demonstrate the role of a surface nonautonomous phase (NP) in the incorporation of gold in this mineral. The distribution coefficient of gold between pyrite and hydrothermal solution is 0.14 for “pure” pyrite and 0.05 for As-bearing pyrite (containing 0.02–0.05 wt % As), and these coefficients for NP are 310 and 170, respectively. This increases the Dbulk for evenly distributed (“invisible”) gold by factors of four and nine. In contrast to the results of earlier studies conducted at room temperature and pressure or parameters close to them, our data demonstrate that the accumulation of “invisible” Au in pyrite is controlled not only by reducing adsorption with the development of Au(0) particles and films but also by Au incorporation in NP developing in the surface layer of the crystal approximately 500 nm thick as chemically bound Au [most likely as Au(I)]. The possible reason for the high absorption capacity of NP is the defect (pyrrhotite-like) structure, which is not saturated with bonds of excess S and sulfoxi onions.

Cochrane reviews of randomized trials of fluoride therapies for preventing dental caries

To present the evidence summarized in the Cochrane fluoride reviews. An overview of the results of selected systematic reviews. Relevant systematic reviews published in the Cochrane Database of Systematic Reviews (CDSR) were identified by searching 'The Cochrane Library issue 4, 2008', using the terms 'Fluoride' and 'Caries'. Complete Cochrane reviews assessing the effectiveness of any fluoride-based intervention for preventing caries were selected, and their main features and findings were reviewed. 14 papers were identified of which 11 were relevant full-text reviews. The results were assessed of 7 reviews published from 2002 to 2004 concerning the relative effectiveness of 4 topical fluoride treatments (toothpastes, gels, varnishes and mouthrinses) in preventing caries in children and adolescents. Comparisons in these reviews were made against non-fluoride controls, against each other, and against different combinations. Findings from 4 reviews published between 2004 and 2006, assessing other fluoride modalities (slow release devices, milk), specific comparison/site (fluoride varnishes versus sealants in occlusal surfaces), and particular population and caries outcome (fluorides for white spot lesions in orthodontic patients) were also assessed. The 7 reviews confirm a clear and similar effectiveness of topical fluoride toothpastes, mouthrinses, gels and varnishes for preventing caries, and show that additional caries reduction can be expected when another topical fluoride is combined with fluoride toothpaste. Evidence is insufficient to confirm the effectiveness of slow release fluoride devices and fluoridated milk. The comparative effectiveness of other modes of delivering fluoride, such as to orthodontic patients is also as yet unclear. Fissure sealants appear more effective than fluoride varnish for preventing occlusal caries but the size of the difference is unclear. The benefits of topical fluorides are firmly established based on a sizeable body of evidence from randomized controlled trials. The size of the reductions in caries increment in both the permanent and the primary dentitions emphasizes the importance of including topical fluoride delivered through toothpastes, rinses, gels or varnishes in any caries preventive program. However, trials to discern potential adverse effects are required, and data on acceptability. Better quality research is needed to reach clearer conclusions on the effects of slow release fluoride devices, milk fluoridation, sealants in comparison with fluoride varnishes, and of different modes of delivering fluoride to orthodontic patients.

Scattering of SAW at discontinuities: some numerical experiments

In developing models to characterize the metallic-finger step discontinuity in SAW devices on piezoelectric substrates it is important to estimate the SAW reflection coefficients and the effect of other modes at step discontinuities. In the literature perturbation approximations, finite element methods and various phenomenological parameter-fitting using experimental data are among the techniques which have been exploited. In this paper, a nonperturbation approximation method, which attempts to parallel some well-established techniques used in solving electromagnetic waveguide-discontinuity problems, is explored as an alternate numerical procedure for calculating SAW reflections. Implementing such a method requires that the full solution to SAW propagation in the free and in the layered regions be obtained. Thus, for a free-to-metallized discontinuity, the two SAW phase velocities, the total SAW power now in the free region and in the layered region, and the electroacoustic fields, must be calculated. In this paper the reflection problem is formulated as an optimization problem subject to the necessary scattering parameter constraints. Numerical experiments are described, and the results of calculations for reflectivity are compared to perturbation approximations, nonperturbation approximations and the available experimental data for the effects of energy storage.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

6 The use of anti-progesterones as a medical IUD

Mifepristone holds promise as a safe and effective anti-progesterone. Widespread use of mifepristone to regularize cycles or prevent pregnancy, however, cannot be recommended at this time. The drug is promising for these uses but the dose and timing of administration required to achieve optimum effect are unknown. Menses are consistently induced in the mid to late luteal phase at a wide range of doses. Further work needs to be done to examine the luteolytic properties of the drug when given at this time. Knowledge about the serum concentration of the parent compound and its less active metabolites after oral administration may help to explain variable biological effects. The effects of other modes of administration, such as transdermal or transvaginal application which avoid a first-pass effect by the liver, should also be explored. Practical issues of the timing of administration need to be resolved. The drug is not effective when given in the absence of luteal phase levels of progesterone. Thus, verification of luteal phase status before the administration of the drug would be ideal. Basal body temperature monitoring may be one way to do this. There is no other convenient way to determine serum levels of progesterone that would be feasible on a large-scale outpatient basis. Since mifepristone does not regulate the timing of ovulation, the optimal time of administration may vary from cycle to cycle. This presumes a high degree of willingness on the part of the woman to observe her cycles and participate in decisions regarding the timing of the drug. Mifepristone, the first clinically available anti-progesterone, represents a significant advance in fertility control.(ABSTRACT TRUNCATED AT 250 WORDS)

Report of the Federal Panel on Formaldehyde.

The Federal Panel on Formaldehyde concluded that definitive experiments exist which demonstrate the mutagenicity and carcinogenicity of formaldehyde under laboratory conditions. Formaldehyde induces both gene mutations and chromosomal aberrations in a variety of test systems. Inhalation of formaldehyde causes cancer of the nose in rats. The concentrations of formaldehyde in inhaled air that caused nasal cancer in Fisher 344 rats are within the same order of magnitude as those to which humans may be exposed. The data presently available do not permit a direct assessment of the carcinogenicity of formaldehyde to man. Epidemiologic studies on exposed human populations are in progress and may further clarify the situation. Other experimental and human studies on toxic effects such as teratogenicity and reproductive disorders are as yet inadequate for a health risk assessment. The CIIT 24 month study on animal carcinogenicity has not yet been completely evaluated. Additional data are expected on the effects of prolonged exposure to lower doses of formaldehyde and on the possible carcinogenicity of formaldehyde in the mouse. The panel recommends that, for a comprehensive health risk assessment, further experiments be conducted on the effects of other modes of exposure (ingestion and skin penetration), the effects in humans, and on the pharmacokinetics of formaldehyde in man and animals and the possible role for formaldehyde in reproductive and chronic respiratory disorders. It is the conclusion of the panel that formaldehyde should be presumed to pose a carcinogenic risk to humans.