Vaccine-preventable haemophilus influenza type B disease burden and cost-effectiveness of infant vaccination in Indonesia.

BACKGROUND: Most of Asia, including Indonesia, does not use Haemophilus influenzae type b (Hib) conjugate vaccines. We estimated total vaccine-preventable disease burden and the cost-effectiveness of Hib conjugate vaccine in Indonesia. METHODS: Hib pneumonia and meningitis incidences for children with access to health care were derived from a randomized vaccine probe study on Lombok Island, Indonesia during 1998-2002. Incidences were adjusted for limited access to care. Health system and patient out-of-pocket treatment cost data were collected concurrent with the probe study. For Hib vaccine in monovalent and combined (with DTP-HepB) presentations, we used 2007 UNICEF vaccine prices of US$3.30 and$3.75 per dose. RESULTS: For the 2007 Indonesian birth cohort, Hib vaccine would prevent meningitis in 1 of every 179 children, pneumonia in 1 of every 18 children, and 4.9% of mortality among those younger than 5 years. The total incremental societal costs of introducing Hib vaccine in monovalent and pentavalent presentations were, respectively, US$11.74 and$8.93 per child vaccinated. Annual discounted treatment costs averted amounted to 20% of pentavalent vaccine costs. For the pentavalent vaccine, the incremental costs per discounted death and disability adjusted life-year averted amounted to US$3102 and$74, respectively, versus $4438 and$102 for monovalent vaccine. CONCLUSIONS: Routine infant Hib vaccination would prevent a large burden of pediatric illness and death in Indonesia. Even without external funding support, Hib vaccine will be a highly cost-effective intervention in either a monovalent or pentavalent presentation based on commonly used benchmarks

A spectral method for sizing cracks using ultrasonic arrays

Ultrasonic phased array systems are becoming increasingly popular as tools for the inspection of safety-critical structures within the non-destructive testing industry. The datasets captured by these arrays can be used to image the internal structure of individual components, allowing the location and nature of any defects to be deduced. Although there exist strict procedures for measuring defects via these imaging algorithms, sizing flaws which are smaller than two wavelengths in diameter can prove problematic and the choice of threshold at which the defect measurements are made can introduce an aspect of subjectivity. This paper puts forward a completely objective approach specific to cracks based on the Kirchhoff scattering model and the approximation of the resulting scattering matrices by Toeplitz matrices. A mathematical expression relating the crack size to the maximum eigenvalue of the associated scattering matrix is derived. Analysis of this approximation shows that the method will provide a unique crack size for a given maximum eigenvalue whilst providing a quick calculation method which avoids the need to numerically generate model scattering matrices (the computation time is up to 10^3 times faster). A sensitivity analysis demonstrates that the method is most effective for sizing defects that are commensurate with or smaller than the wavelength of the ultrasonic wave. The method is applied to simulated FMC data arising from finite element calculations where the crack length to wavelength ratios range between 0.6 and 1.9. The recovered objective crack size exhibits an error of 12%

In vitro and ex vivo evaluation of N‐methyl benzilates as potential PET agents for muscarinic receptors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90199/1/25802601207_ftp.pd

On carrier spillover in c- and m-plane InGaN light emitting diodes

The internal quantum efficiency(IQE) and relative external quantum efficiency (EQE) in InGaNlight-emitting diodes(LEDs) emitting at 400 nm with and without electron blocking layers (EBLs) on c-plane GaN and m-plane GaN were investigated in order to shed some light on any effect of polarizationcharge induced field on efficiency killer carrier spillover. Without an EBL the EQE values suffered considerably (by 80%) for both orientations, which is clearly attributable to carrier spillover. Substantial carrier spillover in both polarities, therefore, suggests that the polarizationcharge is not the major factor in efficiency degradation observed, particularly at high injection levels. Furthermore, the m-plane variety with EBL did not show any discernable efficiency degradation up to a maximum current density of 2250 A cm−2 employed while that on c-plane showed a reduction by ∼40%. In addition, IQE of m-plane LED structure determined from excitation power dependent photoluminescence was ∼80% compared to 50% in c-plane LEDs under resonant and moderate excitation condition. This too is indicative of the superiority of m-plane LED structures, most probably due to relatively larger optical matrix elements for m-plane orientation

Efficiency retention at high current injection levels in m-plane InGaN light emitting diodes

We investigated the internal quantum efficiency (IQE) and the relative external quantum efficiency (EQE) of m-plane InGaN light emitting diodes(LEDs) grown on m-plane freestanding GaN emitting at ∼400 nm for current densities up to 2500 A/cm2. IQE values extracted from intensity and temperature dependent photoluminescencemeasurements were consistently higher, by some 30%, for the m-plane LEDs than for reference c-plane LEDs having the same structure, e.g., 80% versus 60% at an injected steady-state carrier concentration of 1.2×1018 cm−3. With increasing current injection up to 2500 A/cm2, the maximum EQE is nearly retained in m-plane LEDs, whereas c-plane LEDs exhibit approximately 25% droop. The negligible droop in m-plane LEDs is consistent with the reported enhanced hole carrier concentration and light holes in m-plane orientation, thereby enhanced hole transport throughout the active region, and lack of polarization induced field. A high quantum efficiency and in particular its retention at high injection levels bode well for m-plane LEDs as candidates for general lighting applications

InGaN staircase electron injector for reduction of electron overflow in InGaN light emitting diodes

Ballistic and quasiballistic electron transport across the active InGaN layer are shown to be responsible for electron overflow and electroluminescence efficiency droop at high current levels in InGaN light emitting diodes both experimentally and by first-order calculations. An InGaN staircase electron injector with step-like increased In composition, an “electron cooler,” is proposed for an enhanced thermalization of the injected hot electrons to reduce the overflow and mitigate the efficiency droop. The experimental data show that the staircase electron injector results in essentially the same electroluminescence performance for the diodes with and without an electron blocking layer, confirming substantial electron thermalization. On the other hand, if no InGaN staircase electron injector is employed, the diodes without the electron blocking layer have shown significantly lower (three to five times) electroluminescence intensity than the diodes with the blocking layer. These results demonstrate a feasible method for the elimination of electron overflow across the active region, and therefore, the efficiency droop in InGaN light emitting diodes

Internal quantum efficiency of c-plane InGaN and m-plane InGaN on Si and GaN

We investigated internal quantum efficiency (IQE) of polar (0001) InGaN on c-sapphire, and (11¯00) nonpolar m-plane InGaN on both m-plane GaN and specially patterned Si. The IQE values were extracted from the resonant photoluminescence intensity versus the excitation power. Data indicate that at comparable generatedcarrier concentrations the efficiency of the m-plane InGaN on patterned Si is approximately a factor of 2 higher than that of the highly optimized c-plane layer. At the highest laser excitation employed (∼1.2×1018 cm−3), the IQE of m-plane InGaN double heterostructure on Si is approximately 65%. We believe that the m-plane would remain inherently advantageous, particularly at high electrical injection levels, even with respect to highly optimized c-plane varieties. The observations could be attributed to the lack of polarization induced field and the predicted increased optical matrix elements in m-plane orientation

Towards co-design of rehabilitation technologies: a collaborative approach to prioritize usability issues

IntroductionEarly stakeholder engagement is critical to the successful development and translation of rehabilitation technologies, a pivotal step of which is usability testing with intended end-users. To this end, several methods employ end-user feedback to identify usability and implementation issues. However, the process of prioritizing identified issues seldom leverages the knowledge and expertise of the range of stakeholders who will ultimately affect the demand and supply of a device. This paper describes a novel method to prioritize end-user feedback using transdisciplinary stakeholder consultation and address it in subsequent product development. The proposed approach was demonstrated using a case study relating to the development of a novel technology for neural recovery after spinal cord injury.MethodFeedback from five individuals with chronic spinal cord injury was collected during two-hour usability evaluation sessions with a fully functional high-fidelity system prototype. A think-aloud and semi-structured interview protocol was used with each participant to identify usability and acceptability issues relating to the system in a 3-phase approach. Phase 1 involved extracting usability issues from think-aloud and semi-structured interview data. Phase 2 involved rating the usability issues based on their significance, technical feasibility, and implementation priority by relevant internal and external stakeholders. Finally, Phase 3 involved aggregating the usability issues according to design and implementation elements to facilitate solution generation, and these solutions were then raised as action tasks for future design iterations.ResultsSixty usability issues representing nine facets of usability were rated. Eighty percent of issues were rated to be of moderate to high significance, 83% were rated as being feasible to address, and 75% were rated as addressable using existing project resources. Fifty percent of the issues were rated to be a high priority for implementation. Evaluation of the grouped issues identified 21 tasks which were mapped to the product roadmap for integration into future design iterations.DiscussionThis paper presents a method for meaningful transdisciplinary stakeholder engagement in rehabilitation technology development that can extended to other projects. Alongside a worked example, we offer practical considerations for others seeking to co-develop rehabilitation technologies