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Jackie Leach Scully Erica Haimes Anika Mitzkat Rouven Porz Christoph Rehmann-Sutter 《Journal of bioethical inquiry》2012,9(1):19-28
This paper is based on linked qualitative studies of the donation of human embryos to stem cell research carried out in the
United Kingdom, Switzerland, and China. All three studies used semi-structured interview protocols to allow an in-depth examination
of donors’ and non-donors’ rationales for their donation decisions, with the aim of gaining information on contextual and
other factors that play a role in donor decisions and identifying how these relate to factors that are more usually included
in evaluations made by theoretical ethics. Our findings have implications for one factor that has previously been suggested
as being of ethical concern: the role of gratitude. Our empirical work shows no evidence that interpersonal gratitude is an
important factor, but it does support the existence of a solidarity-based desire to “give something back” to medical research.
Thus, we use empirical data to expand and refine the conceptual basis of bioethically theorizing the IVF–stem cell interface. 相似文献
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The aim of this research is to investigate the relationship between obesity and wages, using data for nine countries from the European Community Household Panel (ECHP) over the period 1998-2001. We improve upon the existing literature by adopting a Quantile Regression approach to characterize the heterogenous impact of obesity at different points of the wage distribution. Our results show that (i) the evidence obtained from mean regression and pooled analysis hides a significant amount of heterogeneity as the relationship between obesity and wages differs across countries and wages quantiles and (ii) cultural, environmental or institutional settings do not seem to be able to explain differences among countries, leaving room for a pure discriminatory effect hypothesis. 相似文献
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Maree Porter Ian H. Kerridge Christopher F. C. Jordens 《Journal of bioethical inquiry》2012,9(1):41-47
Umbilical cord blood banking is one of many biomedical innovations that confront pregnant women with new choices about what
they should do to secure their own and their child’s best interests. Many mothers can now choose to donate their baby’s umbilical
cord blood (UCB) to a public cord blood bank or pay to store it in a private cord blood bank. Donation to a public bank is
widely regarded as an altruistic act of civic responsibility. Paying to store UCB may be regarded as a “unique opportunity”
to provide “insurance” for the child’s future. This paper reports findings from a survey of Australian women that investigated
the decision to either donate or store UCB. We conclude that mothers are faced with competing discourses that force them to
choose between being a “good mother” and fulfilling their role as a “good citizen.” We discuss this finding with reference
to the concept of value pluralism. 相似文献
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猪流感(Swine influenza,SI)是由甲型流感病毒引起的猪急性呼吸道传染病,不仅给养猪业带来了极大的危害,还严重危害人类健康,因此引起全球公共卫生的关注。猪对哺乳动物流感病毒和禽流感病毒都易感,被认为是二者之间进行基因重配和跨种传播的重要中间宿主,也是产生引起人类流感大流行毒株的重要来源。目前全球猪群中流行的流感病毒以H1N1、H3N2以及H1N2亚型为主,但各地流行的猪流感病毒(Swine influenza viruses,SIVs)谱系或基因节段的来源均有差异。北美地区近期暴发的猪流感三源重配H3N2/H1N2亚型变异株感染人的事件再次提醒我们要密切关注SIV对公共卫生的威胁。因此,监测和研究甲型流感病毒在全球猪群中的流行动态对于大流行应对是非常重要的。 相似文献
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M. Sj?str?m J. Lexell A. Eriksson C. C. Taylor 《European journal of applied physiology and occupational physiology》1991,62(5):301-304
Cross-sections (thickness 10 microns) of whole autopsied left and right anterior tibialis muscles of seven young previously healthy right-handed men (mean age 23 years, range 18-32 years) were prepared for light-microscope enzyme histochemistry. Muscle cross-sectional area and total number of fibres, mean fibre size (indirectly determined) and proportion of the different fibre types (type 1 and type 2 on basis of myofibrillar adenosine triphosphatase characteristics), in each muscle cross-section were determined. The analysis showed that the cross-sectional area of the left muscle was significantly larger (P less than 0.05), and the total number of fibres was significantly higher (P less than 0.05), than for the corresponding right muscle. There was no significant difference for the mean fibre size or the proportion of the two fibre types. The results imply that long-term asymmetrical low-level daily demands on muscles of the left and the right lower leg in right-handed individuals provide enough stimuli to induce an enlargement of the muscles on the left side, and that this enlargement is due to an increase in the number of muscle fibres (fibre hyperplasia). Calculations based on the data also explain why the underlying process of hyperplasia is difficult, or even impossible, to detect in standard muscle biopsies. 相似文献
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《Biophysics》2010,55(5):838-839
Chronicles
International symposium “Biological motility: From fundamental achievements to nanotechnologies” Pushchino, Moscow Region, Russia, May 11–15, 2010 相似文献9.
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A forest’s productivity can be optimized by the application of rules derived from monopolized circles. A monopolized circle
is defined as a circle whose center is a tree and whose radius is half of the distance between the tree itself and its nearest
neighbor. Three characteristics of monopolized circle are proved. (1) Monopolized circles do not overlay each other, the nearest
relationship being tangent. (2) “Full uniform pattern” means that the grid of trees (a×b=N) covers the whole plot, so that the distance between each tree in a row is the same as the row spacing. The total monopolized
circle area with a full uniform pattern is independent on the number of trees and
times the plot area. (3) If a tree is removed, the area of some trees’ monopolized circle will increase without decreasing
the monopolized circles of the other trees. According to the above three characteristics, “uniform index” is defined as the
total area of monopolized circles in a plot divided by the total area of the monopolized circles, arranged in a uniform pattern
in the same shaped plot. According to the definition of monopolized circle, the distribution of uniform index
for a random pattern and
the variance of L is
. It is evident that E(L) is independent on N and the plot area; hence, L is a relative index. L can be used to compare the uniformity among plots with different areas and the numbers of trees. In a random pattern, where
L is equivalent to the tree density of the plot in which the number of trees is 1 and the area is π, the influence of tree number and plot area to L is eliminated. When n→∞, D(L)→0 and
it indicates that the greater the number of tree is in the plots, the smaller the difference between the uniform indices
will be. There are three types of patterns for describing tree distribution (aggregated, random, and uniform patterns). Since
the distribution of L in the random pattern is accurately derived, L can be used to test the pattern types. The research on Moarshan showed that the whole plot has an aggregated pattern; the
first, third, and sixth parts have an aggregated pattern; and the second, fourth, and fifth parts have a random pattern. None
of the uniform indices is more than 0.318 (1/∏), which indicates that uniform patterns are rare in natural forests. The rules
of uniform index can be applied to forest thinning. If you want to increase the value of uniform index, you must increase
the total area of monopolized circles, which can be done by removing select trees. “Increasing area trees” are the removed
trees and can increase the value of the uniform index. A tree is an increasing area tree if the distance between the tree
and its second nearest neighbor is
times longer than that between the tree itself and its first nearest neighbor, which is called the
rule. It was very interesting to find that when six plots were randomly separated from the original plot, the proportion
of increasing area trees in each plot was always about 0.5 without exception. In random pattern, the expected proportion of
increasing area trees is about 0.35–0.44, which is different from the sampling value of 0.5. The reason is very difficult
to explain, and further study is needed. Two criteria can be used to identify which trees should be removed to increase the
uniform index during forest thinning. Those trees should be (1) trees whose monopolized circle areas are on the small side
and (2) increasing area trees, which are found via the
rule.
Translated from Acta Ecologica Sinica, 2005, 25(1) (in Chinese) 相似文献
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Aerobiology 1992 June 9–11, 1992Scarborough College University of Toronto Toronto, Ontario Canada Symposium of the Pan-American Aerobiology Association 相似文献
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Knowledge of which biological and functional traits have,or lack,phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities.Allometric biomass models reflecting tree growth characteristics are commonly used to predict forest biomass.However,few studies have examined whether model parameters are constrained by phylogeny.Here,we use a comprehensive database(including 276 tree species) compiled from 894 allometric bio... 相似文献
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Zusammenfassung Zwei Wellensittiche und ein Stieglitz hatten gelernt, einen links an einer Klapptür befindlichen Haken mit einer bogenförmigen Bewegung im Uhrzeigersinn aus einer Öse zu entfernen und danach die entriegelte Tür von links nach rechts aufzuklappen. Bei einem Positionswechsel von Riegel und Türöffnungskante nach rechts zeigten die VÖgel zunächst eine Ortsfixierung auf links. Nachdem sie den Seitenwechsel vollzogen hatten, mußten sie die nun erforderliche gegensinnige Öffnungsbewegung neu erlernen. Eine Einsicht in den Funktionszusammenhang fehlte und somit auch ein Problemverständnis.In einer weiteren Aufgabe hatten die VÖgel primär gelernt, eine Tür hochzuschieben, nachdem sie an der linken Türseite drei blockierende Holzstifte aus Bohrungen gezogen hatten. Traten die Stifte nun an der rechten statt linken Seite auf, manipulierten die Wellensittiche entsprechend ihrer Ortsfixierung zunächst nur links; dem Stieglitz genügte die optische Überprüfung der Situation zur Neuroientierung. Sobald sie aber den Positionswechsel beachteten, lösten Wellensittiche wie Stieglitz das Problem in altbekannter Manier. Das taten sie auch bei sukzessiver Erhöhung der Stiftzahl auf zehn (fünf rechts, fünf links) und ebenso, wenn sich Größe, Form und Farbe der Stifte änderte. Sie handelten im Sinne eines positiven Transfers, d. h. sie ordneten die visuelle Information in ein Schema ein, das die entsprechende Operation (Ziehen) auslöste.
Transfer tests in solving problem box tasks in birds:Melopsittacus undulatus andCarduelis carduelis
Summary Confronted with a snapdoor (hinges on the right) with a hook on the left side two Budgerigars and a Goldfinch had learnt to unfasten the hook clockwise and push the door open from the left to the right. In a test door, hinges, and fastening were presented mirror-inverted: At first the birds were fixated to the previous place of manipulation on the left. After having turned to the right side of the door they nevertheless were not able to open the hook and the door, but had to learn the opening manipulations anew. Thus the birds obviously lack any insight into the nature of the experimental situation.Furthermore, the Budgerigars and the Goldfinch had learnt to open a sliding door by pushing it upwards after having pulled three wooden pins out of bore-holes at the left side of the door. In a transfer test the pins blocked the door at the right side. Due to their fixation to the left the manipulations of the Budgerigars were at first directed to that side; the Goldfinch checked the situation up exclusively by visual control. As soon as the birds turned to the right they all managed the task without any problems. Confronted with an increasing number of pins (up to ten: five on the right, five on the left side of the door) or with pins of different size, shape, or colour the birds showed a positive transfer. They ranged the visual information (pin) along a present conception and thus were able to react correctly (pull it out).相似文献
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病毒样颗粒(Virus-like particles,VLPs)是指由病毒一个或几个结构蛋白自行组装成不含病毒基因组且不能复制、不具有感染能力的病毒样蛋白颗粒。VLPs因能够模拟天然病毒的构象表位而保持了完整病毒颗粒所具有的免疫原性,可诱导机体产生广泛强大的抗病毒免疫反应,阻止病毒侵入机体,在抗病毒性疾病的预防或治疗性疫苗及诊断试剂的研究开发方面具有巨大的应用前景。本文就禽流感病毒样颗粒相关研究进展进行综述,以期为我国禽流感VLPs的研究提供参考。 相似文献
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Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality of this expectation.In this study,we asked whether pollinator dependence decreases along an elevational gradient and how it varies with various reproductive traits.To answer these questions,we quantified pollinator-plant associations and various reproductive traits for 112 flowerin... 相似文献
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Sabater B 《Bio Systems》2006,83(1):10-17
The physiology at limiting and stress conditions challenges the current view that the overall reaction of metabolic processes is always far from equilibrium and, therefore, that organisms are not committed to lower their rates of entropy production. Plausibly, critical steps of natural selection takes place at limiting conditions, near equilibrium, in the linear range response of entropy production, and consequently the trend to lower the rate of entropy production could be the fitness arrow of biological evolution. The evolutionary relevance of the Prigogine theorem is discussed in connection with the ergodic hypothesis of Boltzmann. The emergence of metabolic strategies to economise carbon/energy resources, of resource-waste systems like active transport and the irreversible increase in the complexity of organisms during evolution may be consequences of a more general trend of metabolic systems to lower the rates of entropy production. 相似文献