The Relationship between Health Insurance and Mortality for Cancer Patients: Medicare Advantage versus Fee-For-Service Medicare

Compared to traditional fee-for-service Medicare (FFS), private Medicare Advantage (MA) plans offer additional health insurance coverage but restrict access to medical providers. This study measured how MA enrollment, relative to FFS enrollment, may influence mortality for cancer patients. The study used linked data from the Surveillance, Epidemiology, and End Results Program and Medicare administration (SEER-Medicare) including diagnoses between 2006 and 2011 at all four major cancer sites (breast, colorectal, lung, prostate). The key innovation of the study was to measure and account for variation in prescription drug coverage between MA and FFS cancer patients. Among cancer patients with Part D coverage, MA enrollment was associated with modestly increased mortality. The estimated relationships were statistically distinguishable from zero for lung cancer and (in most model specifications) colorectal cancer. The findings are consistent with a hypothesis that restricted provider access may reduce health outcomes for patients who already have a serious illness

The Namban group of Japanese sword guards: a reappraisal

There has always been a distinct dearth of scholarship with regard to the Namban group of tsuba. Many reasons can be proposed to explain this neglect, but one of these is undoubtedly the very large and disparate number of tsuba that were originally included under this heading. Ogawa's redefinition of the group in 1987 was not without its problems, but has resulted in a much more clearly defined and manageable corpus of work; it is against this background that the present reappraisal is submitted. The early confusions resulting from the use of the term 'Namban' are described and the group is redefined in the light of Ogawa's intervention — many of these defining characteristics are individually examined in some detail. No statistical analysis of tsuba has been published since Gunsaulus' work on a mixed group of 746 artefacts in 1923. In this reappraisal, her results have been compared with those obtained from the examination of a corpus of 273 Namban tsuba, gathered from public and private collections in Europe, and this comparison casts some doubt on Gunsaulus' figures. A comparable analysis of 1,045 arbitrarily selected tsuba, of mixed groups and periods, reinforces this doubt. The case for the use of modern physical methods of chemical analysis in the study of Namban tsuba is considered. It is concluded that the time is not yet ripe to enable the optimal use of such studies, although a case is made for the limited use of electron microscope scanning in order to define the place of mercuric gilding in the often profuse decoration of this group of tsuba. Finally, casting techniques are discussed and evidence is produced of their widespread use in the production of Namban tsuba. It is apparent that the new definition of the Namban group of Japanese sword guards enables a much more focused study of the group, although the absence both of any detailed knowledge of the many Namban workers scattered throughout Japan, and of any inscriptions on their work, remain serious barriers to the systematic attribution of these tsuba

Deformation Response and Life of Metallic Composites

The project was initially funded for one year (for $100,764) to investigate the potential of particulate reinforced metals for aeropropulsion applications and to generate fatigue results that quantify the mean stress effect for a titanium alloy matrix material (TIMETAL 21S). The project was continued for a second year (for$85,000) to more closely investigate cyclic deformation, especially ratcheting, of the titanium alloy matrix at elevated temperature. Equipment was purchased (for $19,000) to make the experimental program feasible; this equipment included an extensometer calibrator and a multi-channel signal conditioning amplifier. The project was continued for a third year ($50,000) to conduct cyclic relaxation experiments aimed at validating the elastic-viscoelastic-viscoplastic model that NASA GRC had developed for the titanium alloy. Finally, a one-year no cost extension was granted to enable continued analysis of the experimental results and model comparisons

A Fully Coupled Model for Actuation of Higher Order Modes of Lamb Waves

Lamb waves have proven to be a valuable tool for structural health monitoring (SHM) of plate-like structures susceptible to degradation. It is well-known that the multi-modal propagation characteristics provide both challenges and opportunities. Piezoelectric transducers are widely used in SHM applications because of their low cost, small profile and strong electromechanical coupling. Properly designing a piezoelectric transducer to excite a particular mode is of great importance to successful SHM practice. The mode tuning capability of piezoelectric transducers has been studied both theoretically and experimentally in the literature for exciting A0 and S0 modes. However, the tuning characteristics of higher order Lamb waves have been studied far less. Also, the transducer is usually modeled separately from the waveguide and their coupling is typically through the in-plane surface tractions. This assumption may induce inaccuracy if the dynamics of actuator are not negligible. The presence of the transducer can also interact with the waves being generated or received, especially if the transducer footprint is substantial. Additionally, the driving circuit is not usually included in the current actuator-waveguide model and thus the power of excited waves cannot be evaluated. In this work, a fully coupled finite element analysis model created for general Lamb wave excitation using piezoelectric transducers is developed. The model comprises three components, electrical driving circuit, piezoelectric element and linear elastic waveguide. The design of the piezoelectric transducer, i.e. width and thickness, for higher order Lamb wave mode excitation is performed for both aluminum and CFRP plates. The design is optimized for both mode tuning capability and power delivery. Experiments are carried out to verify the design

Towards An Economics Policy Framework to Combat Malaria, in An Era of Insecticide Resistance

Malaria causes close to half a million deaths per year, the majority of which are in children under five years of age who live in sub-Saharan Africa. Despite significant progress in reducing malaria deaths in the past fifteen years, there is still a long way to go before universal coverage with key interventions like LLINs and IRS is reached, which is an essential step towards achieving malaria elimination. While severe resource constraints pose a fundamental challenge, growing resistance to insecticides used in LLIN and for IRS exacerbates this issue, and threatens to undermine the significant gains achieved to date. This IPPI Policy Brief draws from economic theory to analyse the case of insecticide resistance. It highlights some fundamental trade-offs brought about by the emergence of resistance to insecticides, as well as the lack of data that is necessary to analyse them. The paper also explores how the concept of market failure is applied in the field of malaria control, and where market inefficiencies have not yet been adequately addressed. Overall, while there is no doubt that significant additional funding is needed to combat malaria and hopefully to move closer to its elimination, there is an urgent need to use sound economic analysis to help develop and strengthen a global rationale for further public investment in malaria vector control and to better take account of insecticide resistance in the prioritisation and deployment of national, in-country programmes

Critique of Macro Flow/Damage Surface Representations for Metal Matrix Composites Using Micromechanics

Guidance for the formulation of robust, multiaxial, constitutive models for advanced materials is provided by addressing theoretical and experimental issues using micromechanics. The multiaxial response of metal matrix composites, depicted in terms of macro flow/damage surfaces, is predicted at room and elevated temperatures using an analytical micromechanical model that includes viscoplastic matrix response as well as fiber-matrix debonding. Macro flow/damage surfaces (i.e., debonding envelopes, matrix threshold surfaces, macro 'yield' surfaces, surfaces of constant inelastic strain rate, and surfaces of constant dissipation rate) are determined for silicon carbide/titanium in three stress spaces. Residual stresses are shown to offset the centers of the flow/damage surfaces from the origin and their shape is significantly altered by debonding. The results indicate which type of flow/damage surfaces should be characterized and what loadings applied to provide the most meaningful experimental data for guiding theoretical model development and verification

The sub-lethal effects of pyrethroid exposure on Anopheles gambiae s.l. life-history traits, behaviour, and the efficacy of insecticidal bednets

Malaria control progress in Africa has stalled. Though the reasons for this will be multifaceted, increasing and intense resistance to pyrethroids in Anopheles gambiae s.l. is almost certainly a contributing factor. Standard methods to monitor insecticide resistance and evaluate vector control tools primarily focus on the immediate and lethal effects on the mosquito. These methods disregard other important delayed and sub-lethal effects, despite their implications for malaria transmission. In response to growing concerns over the sustained effectiveness of current control tools, next-generation products are being developed and evaluated. These aim to target insecticide-resistant mosquitoes or mosquitoes that contribute to residual malaria transmission. Adaptations to current standard efficacy tests are needed to evaluate the novel modes of action of such products. The effect of insecticide exposure on the longevity, reproductive output and blood-feeding behaviour of a wild highly pyrethroid-resistant Anopheles gambiae s.l. population was evaluated. Mosquitoes were exposed to a range of insecticides and insecticidal bednets using laboratory tests and semi-field experimental hut trials. Benchtop video tests were evaluated for their feasibly in measuring the effectiveness of standard and next-generation nets. Subsequently, these tests were used to investigate the behaviour of field-populations of An. gambiae s.l. at the bednet interface in response to a human host. Following exposure to both pyrethroid-only and next-generation nets, evidence of sub-lethal impacts were limited or non-existent. The mosquitoes exposed to insecticidal nets did not suffer from reduced lifespan or altered reproductive output. Evidence of delayed mortality was only recorded when mosquitoes were exposed to extremely high levels of pyrethroids in WHO tube bioassays. Some mosquitoes were inhibited from blood-feeding in experimental hut trials, however, lab tests suggest this effect is absent by 8-hour post net-exposure. The efficacy of next-generation nets on the field population was dependant on the product. Brief contact with PermaNet 3.0 roof (pyrethroid + PBO) caused rapid knock-down and 100% mortality in all tests. Exposure to all other insecticidal nets, including Interceptor G2 (pyrethroid + chlorfenapyr), resulted in low 24-hour mortality in both lab and semi-field experiments. Following adaptations for the field, video tests were able to collect behavioural data on mosquito responses to insecticidal nets such as flying, resting, and probing behaviour. Responses were similar between untreated and pyrethroid- only netting. Extreme reductions in activity were observed following exposure to PermaNet 3.0, and Interceptor G2 showed signs of repellence. The results suggest community protection offered by first-generation LLINs is extremely low in this setting, however, pyrethroid-PBO nets appear to be effective at controlling the highly pyrethroid-resistant population. This work highlights the need for additional studies of sub-lethal effects in other field populations, with lower insecticide resistance levels or differing mechanisms, to establish if such measurements should be incorporated into the evaluation of novel vector control tools

Anopheles gambiae populations from Burkina Faso show minimal delayed mortality after exposure to insecticide-treated nets

Background: The efficacy of long-lasting insecticidal nets (LLINs) in preventing malaria in Africa is threatened by insecticide resistance. Bioassays assessing 24-hour mortality post-LLIN exposure have established that resistance to the concentration of pyrethroids used in LLINs is widespread. However, although mosquitoes may no longer be rapidly killed by LLIN exposure, a delayed mortality effect has been shown to reduce the transmission potential of mosquitoes exposed to nets. This has been postulated to partially explain the continued efficacy of LLINs against pyrethroid-resistant populations. Burkina Faso is one of a number of countries with very high malaria burdens and pyrethroid-resistant vectors, where progress in controlling this disease has stagnated. We measured the impact of LLIN exposure on mosquito longevity in an area of the country with intense pyrethroid resistance to establish whether pyrethroid exposure was still shortening mosquito lifespan in this setting. Methods: We quantified the immediate and delayed mortality effects of LLIN exposure using standard laboratory WHO cone tests, tube bioassays and experimental hut trials on Anopheles gambiae populations originating from the Cascades region of Burkina Faso using survival analysis and a Bayesian state-space model. Results: Following single and multiple exposures to a PermaNet 2.0 LLIN only one of the four mosquito populations tested showed evidence of delayed mortality. No delayed mortality was seen in experimental hut studies using LLINs. A delayed mortality effect was only observed in WHO tube bioassays when deltamethrin concentration was increased above the standard diagnostic dose. Conclusions: As mosquito pyrethroid-resistance increases in intensity, delayed effects from LLIN exposure are substantially reduced or absent. Given the rapid increase in resistance occurring in malaria vectors across Africa it is important to determine whether the failure of LLINs to shorten mosquito lifespan is now a widespread phenomenon as this will have important implications for the future of this pivotal malaria control tool

Flow/Damage Surfaces for Fiber-Reinforced Metals having Different Periodic Microstructures

Flow/damage surfaces can be defined in terms of stress, inelastic strain rate, and internal variables using a thermodynamics framework. A macroscale definition relevant to thermodynamics and usable in an experimental program is employed to map out surfaces of constant inelastic power in various stress planes. The inelastic flow of a model silicon carbide/ titanium composite system having rectangular, hexagonal, and square diagonal fiber packing, arrays subjected to biaxial stresses is quantified by flow/damage surfaces that are determined numerically from micromechanics. using both finite element analysis and the generalized method of cells. Residual stresses from processing are explicitly included and damage in the form of fiber-matrix debonding under transverse tensile and/or shear loading is represented by a simple interface model. The influence of microstructural architecture is largest whenever fiber-matrix debonding is not an issue, for example in the presence of transverse compressive stresses. Additionally, as the fiber volume fraction increases, so does the effect of microstructural architecture. With regard to the micromechanics analysis, the overall inelastic flow predicted by the generalized method of cells is in excellent agreement with that predicted using a large number of displacement-based finite elements

Investigation of Anomalous Behavior in Metallic-Based Materials Under Compressive Loading

An anomalous material response has been observed under the action of applied compressive loads in fibrous SiC/Ti (both Ti-6242 and Ti-15-3 alloys) and the monolithic nickel-base alloy IN-718 in the aged condition. The observed behavior is an increase, rather than a decrease, in the instantaneous Young's modulus with increasing load. This increase is small, but can be significant in yield surface determination tests, where an equivalent offset strain on the order of 10 micron(1 x 10(exp -6) m/m) is being used. Stiffening has been quantified by calculating offset strains from the linear elastic loading line. The offset strains associated with stiffening during compressive loading are positive and of the same order as the target offset strains in yield surface determination tests. At this time we do not have a reasonable explanation for this response nor can we identify a deformation mechanism that might cause it. On the other hand, we are not convinced that it is an artifact of the experimental procedure because a number of issues have been identified and seemingly ruled out. In fact, stiffening appears to be temperature dependent, since it decreases as the temperature increases