Definition of the problem Rationing fairly remains a problem of great importance in most health care systems. While the scientific debate of this challenge is longstanding, few criteria of allocation have gained general approval within the literature and in policy making. In this article, we analyse the fairness and applicability of marginal effectiveness as a rationing criterion. Arguments In the so-called “futility-debate” of the 1990s, arguments for and against the concept of futile medical care were weighted against each other from the point of view of clinical medicine. At the time, the use of “futility” as a rationing criterion was strictly refused. In this article, we concentrate on a specific class of interventions which figured in this dispute, namely medical interventions with marginal effectiveness. We define two dimensions of marginal effectiveness and discuss several arguments in favour and against using these as rationing criteria. Arguments in favour are in particular: 1) the ethical advantages in comparison with cost-benefit-analyses, 2) the potential of transparent resource allocation, 3) the absence of discrimination, and 4) the compatibility with arguments from good clinical practice. However, we explore several problematic issues of definition and implementation which also have to be taken into account. Conclusion We argue that, barring pragmatic issues, marginal effectiveness is a fair and transparent rationing criterion which has many advantages when compared to other controversial criteria. 相似文献
Dense α-sialon materials were produced by hot isostatic pressing (HIP) and post-hot isostatic pressing (post-HIP) using compositions with the formula Y x (Si12–4.5 x , Al4.5 x )-(O1.5 x ,N16–1.5 x ) with 0.1 ≤ x ≤ 0.9 and with the same compositions with extra additions of yttria and aluminum nitride. X-ray diffraction analyses show how the phase content changes from large amounts of β-sialon ( x = 0.1) to large amounts of α-sialon ( x = 0.4) and increasing amounts of mellilite and sialon polytypoids ( x = 0.8). Samples HIPed at 1600°C for 2 h contained unreacted α-silicon nitride, while those HIPed at 1750°C for 1 h did not. This could be due to the fact that the time is to short to achieve equilibrium or that the high pressure (200 MPa) prohibits α-sialon formation. Sintering at atmospheric pressure leads to open porosity for all compositions except those with excess yttria. Therefore, only samples with excess yttria were post-HIPed. Microstructrual analyses showed that the post-HIPed samples had the highest α-sialon content. A higher amount of α-sialon and subsequently a lower amount of intergranular phase were detected at x = 0.3 and x = 0.4 in the post-HIPed samples in comparison to the HIPed. The hardness (HV10) and fracture toughness ( K IC) did not differ significantly between HIPed and post-HIPed materials but vary with different x values due to different phase contents. Measurements of cell parameters for all compositions show a continuous increase with increasing x value which is enhanced by high pressure at high x values. 相似文献
The aging society in many developed countries has made an ergonomic workplace design to an important topic among researchers and practitioners alike. We investigate the workplace design for order pickers that manually collect items from the shelves of a warehouse. Specifically, we treat the storage assignment, i.e., the placement of products in shelves of different height, and zoning, i.e., the partitioning of the storage space into areas assigned to separate pickers, in the fast pick area of a warehouse. A fast pick area unifies the most fast-moving items in a compact area, so that workers are relieved from unproductive travel, but face extraordinary ergonomic risks due to the frequent repetition of picking operations. Concerning the health of (aged) workers, it is crucial to reduce such risks. Thus, we define a combined ergonomic storage assignment and zoning problem with the objective of minimizing the maximum ergonomic burden among all workers. This problem is formalized, and two construction heuristics and a tabu search procedure are proposed. Our results show that neglecting ergonomic aspects and only focusing on picking performance leads to much higher ergonomic risks of the workforce.
Leptin plays an important role in thermoregulation and is possibly associated with the microevolutionary processes of human adaptation to a cold climate. In this study, based on the Yakut population (n = 281 individuals) living in the coldest region of Siberia (t°minimum −71.2 °C), we analyze the serum leptin levels and data of 14 single nucleotide polymorphisms (SNPs) of 10 genes (UCP1, UCP2, UCP3, FNDC5, PPARGC1A, CIDEA, PTGS2, TRPV1, LEPR, BDNF) that are possibly involved in nonshivering thermogenesis processes. Our results demonstrate that from 14 studied SNPs of 10 genes, 2 SNPs (the TT rs3811787 genotype of the UCP1 gene and the GG rs6265 genotype of the BDNF gene) were associated with the elevated leptin levels in Yakut females (p < 0.05). Furthermore, of these two SNPs, the rs3811787 of the UCP1 gene demonstrated more indications of natural selection for cold climate adaptation. The prevalence gradient of the T-allele (rs3811787) of UCP1 increased from the south to the north across Eurasia, along the shore of the Arctic Ocean. Thereby, our study suggests the potential involvement of the UCP1 gene in the leptin-mediated thermoregulation mechanism, while the distribution of its allelic variants is probably related to human adaptation to a cold climate. 相似文献
The currentness of space data application in local and regional real-time estimation of the natural environment state in a mining area is substantiated in the article. The authors give and analyze satellite measurements of the natural environment in a mining area in terms of Olimpiada gold open-cut mine, the Krasnoyarsk Territory. 相似文献
Generalization of the global optimization problem based on a stochastic approach is considered. The concept of a stochastic
(or unimodal in the mean) fuction is introduced. To find the optimal solution, a heuristic self-organization procedure is
proposed.
Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 157–166, January–February, 2000. 相似文献
A new method of light collection in a scintillation plate with wavelength-shifting fibers is described. Using this method, it is possible to determine the coordinates of charged particles traversing the plate. The spatial resolution of the system is comparable to the scintillation-plate thickness and competitive in comparison with the resolution of wire chambers. The results of the experimental testing are presented. 相似文献
The reflection spectra of uninfiltrated and Ba(NO3)2-infiltrated synthetic opal crystals have been measured using a halogen lamp with a quasi-continuous near-UV through IR spectrum as the light source. The spectra have been analyzed in a specular geometry at angles of incidence from 5° to 45°. The specular reflection spectra show a prominent maximum whose position depends on the angle of incidence. The infiltration of opal with barium nitrate shifts the maximum to longer wavelengths by 50 to 100 nm, depending on the angle of incidence. This effect has been interpreted in terms of the photonic band gap, which depends on the angle of incidence and the refractive index of the material filling the pores. The experimental data are in reasonable agreement with the peak-reflectance wavelengths calculated using well-known relations for Bragg diffraction. 相似文献