共查询到20条相似文献,搜索用时 15 毫秒
1.
The inconsistency of predictions from solution concepts of conventional game theory with experimental observations is an enduring question. These solution concepts are based on the canonical rationality assumption that people are exclusively self-regarding utility maximizers. In this article, we think this assumption is problematic and, instead, assume that rational economic agents act as if they were maximizing their implicit utilities, which turns out to be a natural extension of the canonical rationality assumption. Implicit utility is defined by a player's character to reflect his personal weighting between cooperative, individualistic, and competitive social value orientations. The player who actually faces an implicit game chooses his strategy based on the common belief about the character distribution for a general player and the self-estimation of his own character, and he is not concerned about which strategies other players will choose and will never feel regret about his decision. It is shown by solving five paradigmatic games, the Dictator game, the Ultimatum game, the Prisoner's Dilemma game, the Public Goods game, and the Battle of the Sexes game, that the framework of implicit game and its corresponding solution concept, implicit equilibrium, based on this alternative assumption have potential for better explaining people's actual behaviors in social decision making situations. 相似文献
2.
Tooley M 《Bioethics》1998,12(2):111-124
Is there a prima facie obligation to produce additional individuals whose lives would be worth living? In his paper ‘Is it Good to Make Happy People?’, Stuart Rachels argues not only that there is, but, also, that precisely as much weight should be assigned to the quality of life that would be enjoyed by such potential persons, if they were to be actualized, as to the quality of life enjoyed by actually existing persons. In response, I shall argue, first, that Rachels’ view is exposed to very serious objections, and secondly, that his arguments in support of his position involve a crucial assumption, which cannot be sustained, concerning the relation between, on the one hand, propositions about good-making and bad-making properties, and, on the other, propositions about right-making and wrong-making ones. I shall then argue that there is a very plausible position concerning the conditions under which an action can be morally wrong which entails the following asymmetry: there is a prima facie obligation not to bring into existence individuals whose lives are not worth living, but there is no corresponding obligation to create additional individuals whose lives would be worth living. 相似文献
3.
The annual percent change (APC) is often used to measure trends in disease and mortality rates, and a common estimator of this parameter uses a linear model on the log of the age-standardized rates. Under the assumption of linearity on the log scale, which is equivalent to a constant change assumption, APC can be equivalently defined in three ways as transformations of either (1) the slope of the line that runs through the log of each rate, (2) the ratio of the last rate to the first rate in the series, or (3) the geometric mean of the proportional changes in the rates over the series. When the constant change assumption fails then the first definition cannot be applied as is, while the second and third definitions unambiguously define the same parameter regardless of whether the assumption holds. We call this parameter the percent change annualized (PCA) and propose two new estimators of it. The first, the two-point estimator, uses only the first and last rates, assuming nothing about the rates in between. This estimator requires fewer assumptions and is asymptotically unbiased as the size of the population gets large, but has more variability since it uses no information from the middle rates. The second estimator is an adaptive one and equals the linear model estimator with a high probability when the rates are not significantly different from linear on the log scale, but includes fewer points if there are significant departures from that linearity. For the two-point estimator we can use confidence intervals previously developed for ratios of directly standardized rates. For the adaptive estimator, we show through simulation that the bootstrap confidence intervals give appropriate coverage. 相似文献
4.
Samuel J. Rogal 《The Yale journal of biology and medicine》1978,51(1):81-90
While John Wesley''s Primitive Physick (1747) cannot be termed a classic of British medical literature, it must certainly be identified as one of the most popular volumes published in England during the eighteenth century. Although the work came under attack from contemporary surgeons, physicians, and apothecaries, who maintained that its remedies were founded upon ignorance, Wesley probably knew as much as most members of the medical profession; in fact, on no less than twenty instances throughout the volume, he paraphrases or cites directly from prominent physicians and theorists—such figures as Sydenham, Boerhaave, Cheyne, Mead, and Huxham. However, despite its obvious emphasis upon practical remedies, the underlying focus of Primitive Physick is upon the soul of man. Wesley had consulted some sources, common sense, and his own experience, tempering those with the general principle of “doing good to all men,” particularly “those who desire to live according to the gospel....” Thus, the Methodist patriarch''s own formula for life had as much to do with the spread of Primitive Physick throughout eighteenth-century Britain and America as did all of the remedies and suggestions imprinted upon its pages. 相似文献
5.
The present study was conducted in five villages around the Nazinga Game Ranch, Burkina Faso. Fifty informants of the Gourounsi ethnic group were used. Eighty-one useful woody species were identified, out of a total of 110 woody species in the area. Woody plant use was quantified as: edible fruits (28 species), vegetable sauce (22 species), firewood (33 species), construction (29 species) and medicine (64 species and 167 remedies). Further, species accumulation curves were used to estimate that more than 650 remedies for medicine are used in the area. The community's knowledge of plants was analysed in relation to age, gender, village of residence and amount of intercultural visits. The knowledge pattern was remarkably uniform, with only two variations: (1) men generally identified more edible fruit trees than women, and (2) one village reported more firewood species than the other four villages. The informants had a variety of opinions concerning the availability of useful plants, but the majority found the availability to be fine and 47% of the informants searched for useable products in the savanna on a daily basis. No correlation was found between an informant's impression of useful products availability and his/her frequency of visits into the savanna. The results show that the Gourounsi people live in intimate relation with the savanna surrounding their villages. They are aware of the environment and are willing to learn and adopt new conservation practices. 相似文献
6.
Browner CH 《Economic botany》1985,39(4):482-504
Despite the existence of 2 government health centers in Mexico's San Francisco township, the use of herbal remedies for the treatment of reproductive health problems and the management of reproduction is almost universal. An ethnographic study conducted in 1980-1981 of 180 women and 126 women investigated use of specific herbal remedies in this highland area. The largest number of reproduction-related medicinal plants used San Francisco are for postpartum recovery. In fact, 80% of the women interviewed reported using only herbal remedies after their last delivery. These remedies are relied on to restore lost blood, heal the birth scar, and stop bleeding. Of the 40% of respondents who reported postpartum hemorrhaging, 70% used herbal remedies. Several of the plants used to treat menorrhagia and hemorrhaging are also used for infertility. The infertility remedies are believed to cleanse the blood and uterus, heal or strengthen the back so the fetus can adhere, help the womb retain the fetus, and cool the blood. Both infertility and miscarriage are attributed to incomplete postpartum recovery. Another large group of medicinal remedies is employed to speed labor or ease labor pains. These remedies are thought to stimulate blood flow or uterine contractions. An additional 15 plants are used to prevent or terminate pregnancy. The mechanism of action in these case is believed to be to both warm the blood to facilitate its flow and irritate the uterus so it will evacuate its contents. Reliance on these remedies derives from Chinantec ethnomedical understandings. Given the persistence of use of herbal remedies in many communities in the Third World, research is needed on their safety and efficacy. 相似文献
7.
Gardner A 《Journal of theoretical biology》2011,284(1):125-129
Why did Darwin fail to develop his insights on kin selection into a proper theory of social adaptation? One suggestion has been that his inadequate understanding of heredity kept the problem out of focus. Here, I determine whether it is possible to develop a quantitative theory of kin selection upon the assumption of blending inheritance. I find that, whilst Hamilton's rule of kin selection can be readily derived under the assumption of blending inheritance, this mechanism complicates the computation of relatedness coefficients, and can even cause them to fluctuate over generations. Nevertheless, I show that the ultimate criterion for selection to favour any social trait - i.e. a time-average of Hamilton's rule - remains the same as under particulate inheritance. By eliminating the gene from the theory of kin selection, I clarify the role that it plays in the theory of social adaptation. 相似文献
8.
Philani B. Mpofu Giorgos Bakoyannis Constantin T. Yiannoutsos Ann W. Mwangi Margaret Mburu 《Biometrical journal. Biometrische Zeitschrift》2020,62(7):1747-1768
Outcome misclassification occurs frequently in binary-outcome studies and can result in biased estimation of quantities such as the incidence, prevalence, cause-specific hazards, cumulative incidence functions, and so forth. A number of remedies have been proposed to address the potential misclassification of the outcomes in such data. The majority of these remedies lie in the estimation of misclassification probabilities, which are in turn used to adjust analyses for outcome misclassification. A number of authors advocate using a gold-standard procedure on a sample internal to the study to learn about the extent of the misclassification. With this type of internal validation, the problem of quantifying the misclassification also becomes a missing data problem as, by design, the true outcomes are only ascertained on a subset of the entire study sample. Although, the process of estimating misclassification probabilities appears simple conceptually, the estimation methods proposed so far have several methodological and practical shortcomings. Most methods rely on missing outcome data to be missing completely at random (MCAR), a rather stringent assumption which is unlikely to hold in practice. Some of the existing methods also tend to be computationally-intensive. To address these issues, we propose a computationally-efficient, easy-to-implement, pseudo-likelihood estimator of the misclassification probabilities under a missing at random (MAR) assumption, in studies with an available internal-validation sample. We present the estimator through the lens of studies with competing-risks outcomes, though the estimator extends beyond this setting. We describe the consistency and asymptotic distributional properties of the resulting estimator, and derive a closed-form estimator of its variance. The finite-sample performance of this estimator is evaluated via simulations. Using data from a real-world study with competing-risks outcomes, we illustrate how the proposed method can be used to estimate misclassification probabilities. We also show how the estimated misclassification probabilities can be used in an external study to adjust for possible misclassification bias when modeling cumulative incidence functions. 相似文献
9.
Sarah-Lan Mathez-Stiefel Regine Brandt Susanne Lachmuth Stephan Rist 《Human ecology: an interdisciplinary journal》2012,40(6):909-930
A widespread concern among ethnobiologists is the rapid process of erosion of indigenous environmental knowledge observed worldwide. This paper examines the ongoing transformations of knowledge about natural remedies in the Quechua-speaking Andes. Freelisting exercises and interviews were conducted with 36 households at Bolivian and Peruvian study sites. (Generalized) linear mixed-effects models were used to analyze the effects of age on knowledge about medicinal plants, animals, minerals, and their uses. Our study demonstrates that younger participants knew as much about natural remedies as their elders. However, proportional knowledge about some medicinal use categories of natural remedies varied with age. We conclude that knowledge about natural remedies is generally not being lost at the study sites. Nevertheless, it is undergoing transformations in terms of specific medicinal uses. A careful understanding of these complex transformation processes is needed to better orient initiatives for the conservation of biocultural diversity in the Andes and elsewhere. 相似文献
10.
Cassier M 《Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences》2005,36(4):722-742
Whereas Pasteur patented the biotechnological processes that he invented between 1857 and 1873 in the agro-food domain, he did not file any patents on the artificial vaccine preparation processes that he subsequently developed. This absence of patents can probably be explained by the 1844 patent law in France that established the non-patentable status of pharmaceutical preparations and remedies, including those for use in veterinary medicine. Despite the absence of patents, the commercial exploitation of the anthrax vaccine in the 1880s and 1890s led to a technical and commercial monopoly by Pasteur's laboratory as well as the founding of a commercial company to diffuse the vaccine abroad. Pasteur repeatedly refused to transfer his know-how and anthrax vaccine production methods to foreign laboratories, on the grounds that he wished to control the quality of the vaccines produced. Indeed, it was relatively difficult to transfer a method that was not yet perfectly stabilized in the early 1880s. Pasteur also wanted to maintain the monopoly of his commercial company and to increase the profits from vaccine sales so that the Institut Pasteur could be financially independent. The 'Pasteur anthrax vaccine' operating licences are described and analysed in detail in this article. 相似文献
11.
Charissa S. Varma 《Journal of the history of biology》2009,42(1):119-149
Nineteenth-century British entomologist William Kirby is best known for his generic division of bees based on tongues and his vigorous defence of natural theology. Focusing on these aspects of Kirby’s work has lead many current scholars to characterise Kirby as an “essentialist.” As a result of this characterisation, many important aspects of his work, Monographia Apum Angliæ (1802) have been over-looked or misunderstood. Kirby’s religious devotion, for example, have lead some scholars to assume Kirby used the term “type” for connecting an ontological assumption about essences with a creationist assumption about species fixity, which I argue conceals a variety of ways Kirby employed the term. Also, Kirby frequently cautioned against organising a classification system exclusively by what he called “analytic reasoning,” a style of reasoning 20th century scholars often associate with Aristotelian logic of division. I argue that Kirby’s critique of analytic reasoning brought the virtues of his own methodological agenda into sharp relief. Kirby used familiar metaphors in the natural history literature – Ariadne’s thread, the Eleusinian mysteries, and Bacon’s bee and spider metaphors – to emphasise the virtues of building tradition and cooperation in the goals and methodological practices of 19th century British naturalists. 相似文献
12.
Herbal remedies of the Luo of Siaya District,Kenya: Establishing quantitative criteria for consensus
Data based on independent interviews with 45 herbalists of the Luo of Siaya District, Kenya, comprised 1129 remedy reports and related to 330 species of plants. While 49% of the remedies were encountered only once we list here 66 remedies (49 taxa) that were confirmed through independent reports from three or more individuals. A log-linear model was applied to these data in order to establish criteria for evaluating the likely efficacy of specific remedies. A quantitative interaction effect was calculated for each remedy as a measure of its degree of confirmation. The validity of the values derived from the mathematical model is considered in relation to classical criteria for evaluating ethnomedicinal reports. 相似文献
13.
By incubating the mixture of three cyanobacterial proteins, KaiA, KaiB, and KaiC, with ATP in vitro, T. Kondo and his colleagues in recent work reconstituted the robust circadian rhythm of the phosphorylation level of KaiC. This finding indicates that protein-protein interactions and the associated hydrolysis of ATP suffice to generate the circadian rhythm. Several theoretical models have been proposed to explain the rhythm generated in this “protein-only” system, but the clear criterion to discern different possible mechanisms was not known. In this article, we discuss a model based on two basic assumptions: the assumption of the allosteric transition of a KaiC hexamer and the assumption of the monomer exchange between KaiC hexamers. The model shows a stable rhythmic oscillation of the phosphorylation level of KaiC, which is robust against changes in concentration of Kai proteins. We show that this robustness gives a clue to distinguish different possible mechanisms. We also discuss the robustness of oscillation against the change in the system size. Behaviors of the system with the cellular or subcellular size should shed light on the role of the protein-protein interactions in in vivo circadian oscillation. 相似文献
14.
The zero-sum assumption in neutral biodiversity theory 总被引:5,自引:1,他引:4
The neutral theory of biodiversity as put forward by Hubbell in his 2001 monograph has received much criticism for its unrealistic simplifying assumptions. These are the assumptions of functional equivalence among different species (neutrality), the assumption of point mutation speciation, and the assumption that resources are continuously saturated, such that constant resource availability implies constant community size (zero-sum assumption). Here we focus on the zero-sum assumption. We present a general theory for calculating the probability of observing a particular species-abundance distribution (sampling formula) and show that zero-sum and non-zero-sum formulations of neutral theory have exactly the same sampling formula when the community is in equilibrium. Moreover, for the non-zero-sum community the sampling formula has this same form, even out of equilibrium. Therefore, the term "zero-sum multinomial (ZSM)" to describe species abundance patterns, as coined by Hubbell [2001. The Unified Neutral Theory of Biodiversity and Biogeography, Princeton University Press, Princeton, NJ], is not really appropriate, as it also applies to non-zero-sum communities. Instead we propose the term "dispersal-limited multinomial (DLM)", thus making explicit one of the most important contributions of neutral community theory, the emphasis on dispersal limitation as a dominant factor in determining species abundances. 相似文献
15.
基于持续高产的近海渔业双寡头捕捞策略 总被引:1,自引:0,他引:1
海洋鱼类是人类一种重要的生活物质资料,当代人在进行渔业捕捞满足自身生活需求时,应合理确定捕捞努力量以实现渔业资源的可持续利用,不危及后代人的需求,假定存在两个捕捞主体,分别就Cournot模型和Stackelbeerg模型分析了两个主体为了自身获得最大持续产量而投入的捕捞努力量,研究表明,与只有一个捕捞主体相比,当存在两个捕捞主体时,每个捕捞主体都将投入更多的捕捞努力量,但最大持续产量不随之增加,甚至还会减少,产生这种后果的原因在于每个主体只考虑自己投入的捕捞 努力量对自己产出量的影响,而不考虑对对方或社会产生的负面影响,对渔业捕捞进行全面规划,综合管理是消除这种后果所必要的。 相似文献
16.
Pasteurella pseudotuberculosis, containing the Escherichia coli plasmid F'lac, transferred its chromosome in an oriented manner to each of five multiply auxotrophic strains of P. pseudotuberculosis. In a mating system containing gelatin, glucose, and phosphate buffer, a maximum of 0.02% of the donor cells transferred lead markers. The donor population was counterselected with nalidixic acid. We established the entry time of seven markers as follows: proline (11 min); arginine (14 min); histidine (14 min); threonine (25 min); lysine (50 min); tyrosine (67 min); and tryptophan (77 min). However, an analysis of the inheritance of unselected markers did not support the simplest assumption that the chromosome was transferred as Origin... pro... arg his... thr... lys... tyr... trp.... The markers common to all five recipients, arg and his, were closely linked, but of the five other markers, each unique to a different recipient strain, only trp was linked to arg and his. Our data suggest that the Pasteurella chromosome is transferred in more than one linkage group. 相似文献
17.
Unproven and disproven remedies continue to abound for illnesses for which conventional treatment is only partially effective. This is particularly true with cancer, for which up to 50% of patients may be receiving unorthodox therapy. This article examines unconventional cancer remedies, their adverse effects, their common factors and the basis for their appeal, as well as what motivates and characterizes patients who choose these treatments. Also discussed is an approach that may be used by the conventional physician for patients who are likely to seek unorthodox treatment. This approach will help patients make the best decision about their treatment and protect them from the hazards of unconventional remedies. 相似文献
18.
A model for nerve cell pattern formation is proposed in this paper. The model is based on some experimental results and an assumption that there is a kind of inhibitive interaction between growing neurites on the same nerve cell. In this paper, this interaction is termed lateral inhibition. A group of ordinary differential equations are used to describe the elongation of the terminal neurite segments of individual nerve cells. Computer simulation and comparison of it with in vitro studies are also made in this paper. 相似文献
19.
It has been shown that the classical binomial form of ascertainment, assuming a constant probability pi that any affected individual may become a proband for his pedigree, cannot describe a rather wide range of ascertainment procedures that might arise in practice. Some more general heuristic ascertainment formulas might then be preferred, and in this paper we consider the probabilistic basis for these formulas. We retain the binomial assumption of the classical scheme but allow the ascertainment probability to depend on the number of potential probands per pedigree. This probability can be expressed by an increasing or a decreasing function of that number. Various illustrations are given and situations where the "cooperative" binomial scheme should be valuable are discussed. 相似文献
20.
Kariagina AS Naroditskiĭ BS Apt AS Gintsburg AL 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(4):94-101
The review contains information on modern approaches to the development of antituberculosis vaccines and remedies. Data on the comparative effectiveness of different subunit and DNA vaccines against tuberculosis are presented. The use of comparative and structural genomics for the search and characterization of new Mycobacterium tuberculosis genes, whose products may prove to be important antigens for the development of vaccines or target proteins for remedies against tuberculosis, is considered. 相似文献