Parameter Identification of Pressure Sensors by Static and Dynamic Measurements

Fast identification methods of pressure sensors are investigated. With regard to a complete accurate sensor parameter identification two different measurement methods are combined. The approach consists on one hand in performing static measurements - an applied pressure results in a membrane deformation measured interferometrically and the corresponding output voltage. On the other hand optical measurements of the modal responses of the sensor membranes are performed. This information is used in an inverse identification algorithm to identify geometrical and material parameters based on a FE model. The number of parameters to be identified is thereby generally limited only by the number of measurable modal frequencies. A quantitative evaluation of the identification results permits furthermore the classification of processing errors like etching errors. Algorithms and identification results for membrane thickness, intrinsic stress and output voltage will be discussed in this contribution on the basis of the parameter identification of relative pressure sensors.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

A feasibility study of orbiter flight control experiments

The results of a feasibility study of orbiter flight control experiments performed are summarized. Feasibility studies were performed on a group of 14 experiments selected from a candidate list of 35 submitted to the study contractor by the flight control community. Concepts and requirements were developed for the 14 selected experiments and they were ranked on a basis of technical value, feasibility, and cost. It was concluded that all the selected experiments can be considered as potential candidates for the Orbiter Experiment program, which is being formulated for the Orbiter Flight Tests and subsequent operational flights, regardless of the relative ranking established during the study. None of the selected experiments has significant safety implications and the cost of most was estimated to be less than $200K

Immunity to MHC class I antigen after direct DNA transfer into skeletal muscle.

Plasmid cDNA encoding the alpha-chain of either membrane-bound (pcRT.45) or secreted (pcRQ.B3) RT1Aa MHC class I Ag were transferred to Lewis (RT1(1)) rat skeletal muscle by direct injection. Rats were challenged 7 days later with an ACI (RT1a) heterotropic heart transplant, and cardiac allograft survival, RT1Aa-specific antibody levels, and frequency of ACI-specific CTL were monitored. Graft rejection was accelerated by > or = 2 days in an Ag-specific and dose-dependent manner in pcRT.45-injected rats. The pcRQ.B3-injected rats also rejected grafts more rapidly; however, graft rejection was accelerated by only 1 day, and graft infiltrates were less pronounced than in pcRT.45-injected rats. Injection of pcRT.45 resulted in an increase in ACI-specific CTL precursor frequency 3 days post-transplant, whereas there was no significant change in rats pretreated with pcRQ.B3 injection. Compared with rats injected with a control plasmid encoding firefly luciferase, transfer of pcRT.45 resulted in an increase in RT1Aa-specific IgG and IgM antibody 3 days after heart transplantation. Transfer of pcRQ.B3 resulted in a similar mean increase in RT1Aa-specific IgG and IgM antibody after transplantation, but the variability from rat to rat was greater, with some animals exhibiting strong priming, and others showing little or no priming by gene injection. Our results suggest that skeletal muscle can express either membrane-bound or secreted MHC class I Ag after gene transfer, but that the membrane-bound form is more immunogenic than the secreted form in the high responder Lewis rat. Direct DNA transfer to skeletal muscle provides a rapid and specific approach to studying immunity to allogeneic MHC Ag

Use of donor serum to prevent passive transfer of hyperacute rejection

Organ transplantation in presensitized recipients continues to be contraindicated for heart and kidney recipients due to the risk of hyperacute rejection, which has no known treatment at this time. We tested whether donor serum, which contains soluble MHC class I antigen, is able to neutralize the effect of anti-donor antibody in the recipient and prevent hyperacute or accelerated rejection. A rat model of passive immunization was used to test the role of anti-donor antibody in hyperacute rejection. Seven of 10 recipients of hyperimmune serum (HyS), derived from Lewis rats (RT1l) following 3 ACI (RT1a) skin grafts, developed hyperacute or accelerated rejection. Intravenous injection of ACI serum prior to the HyS administration prevented hyperacute rejection in all recipients tested. When third-party (Wistar-Furth, RT1u) serum was given to Lewis rats injected with HyS, hyperacute rejection was not abrogated. When examining the mechanism of this effect, a simple antibody blocking phenomenon was found to be unlikely since flow cytometry analysis showed that ACI serum needed to be present at > or = 256-fold excess compared to HyS to block anti-ACI antibody binding to RT1.Aa+cells by 50%. We tested whether the RT1.Aa class I antigen in ACI serum had other biologic properties that resulted in the prolonged graft survival. However, removal of RT1.Aa antigen from ACI serum prior to use in the passive transfer model did not abrogate the graft prolongation observed previously. These data suggest that components of donor serum other than MHC class I antigen may be useful for preventing the antibody-mediated component of hyperacute rejection

Using microfinance to facilitate household investment in sanitation in rural Cambodia

Improved sanitation access is extremely low in rural Cambodia. Non-governmental organizations have helped build local supply side latrine markets to promote household latrine purchase and use, but households cite inability to pay as a key barrier to purchase. To examine the extent to which microfinance can be used to facilitate household investment in sanitation, we applied a two-pronged assessment: (1) to address the gap between interest in and use of microfinance, we conducted a pilot study to assess microfinance demand and feasibility of integration with a sanitation marketing program and (2) using a household survey ( n = 935) at latrine sales events in two rural provinces, we assessed attitudes about microfinance and financing for sanitation. We found substantial stated intent to use a microfinance institution (MFI) loan to purchase a latrine (27%). Five percent of current owners used an MFI loan for latrine purchase. Credit officers attended 159 events, with 4761 individuals attending. Actual loan applications were low, with 4% of sales events attendees applying for a loan immediately following the event (mean = 1.7 loans per event). Ongoing coordination was challenging, requiring management commitment from the sanitation marketing program and commitment to social responsibility from the MFI. Given the importance of improving sanitation coverage and concomitant health impacts, linking functional sanitation markets to already operational finance markets has the potential to give individuals and households more financial flexibility. Further product research and better integration of private vendors and financing modalities are necessary to create a scalable microfinance option for sanitation markets

Equilibrium free energies from fast-switching trajectories with large time steps

Jarzynski's identity for the free energy difference between two equilibrium states can be viewed as a special case of a more general procedure based on phase space mappings. Solving a system's equation of motion by approximate means generates a mapping that is perfectly valid for this purpose, regardless of how closely the solution mimics true time evolution. We exploit this fact, using crudely dynamical trajectories to compute free energy differences that are in principle exact. Numerical simulations show that Newton's equation can be discretized to low order over very large time steps (limited only by the computer's ability to represent resulting values of dynamical variables) without sacrificing thermodynamic accuracy. For computing the reversible work required to move a particle through a dense liquid, these calculations are more efficient than conventional fast switching simulations by more than an order of magnitude. We also explore consequences of the phase space mapping perspective for systems at equilibrium, deriving an exact expression for the statistics of energy fluctuations in simulated conservative systems

Force-induced unfolding of a homopolymer on fractal lattice: exact results vs. mean field predictions

We study the force-induced unfolding of a homopolymer on the three dimensional Sierpinski gasket. The polymer is subject to a contact energy between nearest neighbour sites not consecutive along the chain and to a stretching force. The hierarchical nature of the lattice we consider allows for an exact treatment which yields the phase diagram and the critical behaviour. We show that for this model mean field predictions are not correct, in particular in the exact phase diagram there is {\em not} a low temperature reentrance and we find that the force induced unfolding transition below the theta temperature is second order.Comment: 15 pages, 5 eps figure

Transitions in Health Insurance During the Perinatal Period Among Patients With Continuous Insurance Coverage

Importance Although health insurance continuity is important during the perinatal period to improve birth outcomes and reduce maternal morbidity and mortality, insurance disruptions are common. However, little is known about insurance transitions among insurance types for individuals who remained insured during the perinatal period. Objective To examine insurance transitions for birthing individuals with continuous insurance, including those with Medicaid and Medicaid managed care coverage, before, during, and after pregnancy. Design, Setting, and Participants This cohort study used January 1, 2014 to December 31, 2018 data from the Massachusetts All-Payer Claims Database. The sample included deliveries from January 1, 2015, to December 31, 2017, to birthing individuals aged 18 to 44 years old with continuous insurance for 12 months before and after delivery. Data were analyzed from November 9, 2021, to September 2, 2022. Exposure Insurance type at delivery. Main Outcomes and Measures The primary outcome was a binary indicator of any transition in insurance type from 12 months before and/or after delivery. The secondary outcomes were measures of any predelivery transition (12 months before delivery month) and any transition during the postpartum period (delivery month to 12 months post partum). Multivariate logit regression models were used to analyze the association of an insurance transition in the perinatal period with insurance type in the delivery month, controlling for age and socioeconomic status based on a 5-digit zip code. Results The analytic sample included 97 335 deliveries (mean [SD] maternal age at delivery, 30.4 [5.5] years). Of these deliveries, 23.4% (22 794) were insured by Medicaid and 28.1% (27 347) by Medicaid managed care in the delivery month. A total of 37.1% of the sample (36 127) had at least 1 insurance transition during the 12 months before and/or after delivery. In regression-adjusted analyses, those individuals covered by Medicaid and Medicaid managed care at delivery were 47.0 (95% CI, 46.3-47.7) percentage points and 50.1 (95% CI, 49.4-50.8) percentage points, respectively, more likely to have an insurance transition than those covered by private insurance. Those covered by Marketplace plans at delivery had a 33.1% (95% CI, 31.4%-34.8%) regression-adjusted predicted probability of having a postpartum insurance transition. Conclusions and Relevance Results of this study showed that insurance transitions during the perinatal period occurred for more than 1 in 3 birthing individuals with continuous insurance and were more common among those with Medicaid or Medicaid managed care at delivery. Further research is needed to examine the role of insurance transitions in health care use and outcomes during the perinatal period

Effective Invariant Theory of Permutation Groups using Representation Theory

Using the theory of representations of the symmetric group, we propose an algorithm to compute the invariant ring of a permutation group. Our approach have the goal to reduce the amount of linear algebra computations and exploit a thinner combinatorial description of the invariant ring.Comment: Draft version, the corrected full version is available at http://www.springer.com