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1.
Many countries have not considered palliative care a public health problem. With limited resources, disease-oriented therapies and prevention measures take priority. In this paper, I intend to describe the moral framework for considering palliative care as a public health priority in resource-poor countries. A distributive theory of justice for health care should consider integrative palliative care as morally required as it contributes to improving normal functioning and preserving opportunities for the individual. For patients requiring terminal care , we are guided less by principles of justice and more by the duty to relieve suffering and society's commitment to protecting the professional's obligation to uphold principles of beneficence, compassion and non-abandonment. A fair deliberation process is necessary to allow these strong moral commitments to serve as reasons when setting priorities in resource poor countries.  相似文献   

2.
Hope T  McMillan J  Hill E 《Bioethics》2012,26(5):259-266
Intensive care units (ICUs) are not always able to admit all patients who would benefit from intensive care. Pressure on ICU beds is likely to be particularly high during times of epidemics such as might arise in the case of swine influenza. In making choices as to which patients to admit, the key US guidelines state that significant priority should be given to the interests of patients who are already in the ICU over the interests of patients who would benefit from intensive care but who have not been admitted. We examine four reasons that in principle might justify such a prioritization rule and conclude that none is convincing. We argue that the current location of patients should not, in principle, affect their priority for intensive care. We show, however, that under some but not all circumstances, maximizing lives saved by intensive care might require continuing to treat in the ICU a patient already admitted rather than transferring that patient out of the unit in order to admit a sicker patient who would also benefit more from intensive care. We conclude that further modelling is required in order to clarify what practical policies would maximize lives saved by intensive care.  相似文献   

3.
Global scarcity of COVID-19 vaccines raises ethical questions about their fair allocation between nations. Section I introduces the question and proposes that wealthy nations have a duty of justice to share globally scarce COVID-19 vaccines. Section II distinguishes justice from charity and argues that beneficiaries of unjust structures incur duties of justice when they are systematically advantaged at others expense. Section III gives a case-based argument describing three upstream structural injustices that systematically advantaged wealthy countries and disadvantaged poorer countries, contributing to global disparities of COVID-19 vaccines. Section IV examines more closely the duties of justice owed, including a duty to relinquish holdings, restitute victims, and restore relationships. Section V concludes that wealthy nations have a duty of justice to share COVID-19 vaccines with poor nations and to restore relationships damaged by injustice. All nations should take steps to transform unjust structures.  相似文献   

4.
Engaging citizens is vital to achieving people‐centred health research. This paper aims to put attention to dynamics of power and dynamics of difference back at the centre of citizen engagement in health research priority‐setting. Without attention to power and difference, engagement can lead to presence without voice and voice without influence, particularly for disadvantaged and marginalised groups. By analysing six key bodies of literature, the paper first identifies the different components of engagement—who initiates, for what purpose, who participates, and how they participate—and the dynamics of power and dynamics of difference relevant to them. For each component of engagement, the ethical considerations relating to those dimensions of power and dimensions of difference are characterised for the research priority‐setting context and preliminary guidance on how they might be addressed is provided. An initial framework comprised of a series of questions reflecting these ethical considerations has been developed for use by researchers and citizens when designing engagement processes for research projects. Where researchers and citizens attend to the framework's questions and then revise their priority‐setting processes’ design to better represent diversity and mitigate power disparities, more inclusive citizen engagement is promoted. Disadvantaged and marginalised groups are more likely to be present and heard, which, in turn, will help generate research projects with topics and questions that encompass and more accurately reflect their health needs.  相似文献   

5.
This article will examine the Catholic concept of global justice within a health care framework as it relates to women's needs for delivery doctors in the developing world and women's demands for assisted reproduction in the developed world. I will first discuss justice as a theory, situating it within Catholic social teachings. The Catholic perspective on global justice in health care demands that everyone have access to basic needs before elective treatments are offered to the wealthy. After exploring specific discrepancies in global health care justice, I will point to the need for delivery doctors in the developing world to provide basic assistance to women who hazard many pregnancies as a priority before offering assisted reproduction to women in the developed world. The wide disparities between maternal health in the developing world and elective fertility treatments in the developed world are clearly unjust within Catholic social teachings. I conclude this article by offering policy suggestions for moving closer to health care justice via doctor distribution.  相似文献   

6.
Adam K. Webb 《Bioethics》2021,35(1):79-89
Medical coverage often stops at borders, for both travellers and long‐term migrants. Such patchiness imposes a de facto limit on free movement. This article considers this phenomenon not as a mere policy choice or technical matter, but as a form of territorial discrimination that is incoherent and even unjust. This legacy of nationally bounded social citizenship rests on a mistaken version of solidarity. Moreover, with growing mobility and rising expectations of medical coverage around the world, the fragmenting of safety nets by the political honeycomb of statehood will become a vexing problem in coming decades. A proper understanding of the health sphere not only can justify incremental reforms that lessen territorial discrimination, without impairing either solidarity or sustainability. It also foreshadows a radically different vision of how social provision might work in a future global space beyond the nation‐state.  相似文献   

7.
The impact of the next influenza pandemic may be mitigated by inducing immunity in individuals prior to the start of national epidemics using a pre-pandemic vaccine targeted against current avian influenza strains. The US Department of Health and Human Services (HHS) intends that pre-pandemic vaccines will be allocated to states in proportion to the size of their population in predefined priority groups, i.e. approximately pro-rata. We show that such an equitable policy is likely to be the least efficient in terms of the number of infections averted. We demonstrate that the potential benefits could be substantial if a fully discretionary policy is allowed, i.e. if some regions are allocated sufficient vaccines to achieve herd immunity while other regions are allocated no vaccine. Since such an inequitable policy may be impractical, we consider the sensitivity of an intermediate policy (in which 50% of the stockpile is allocated on a pro-rata basis) to key transmission uncertainties. The benefits of the 50% discretionary policy are sensitive to parameter values which cannot be known in advance. Therefore, despite substantial potential benefits of non-pro-rata policies, our results suggest that the current HHS policy of pro-rata allocation by state is a good compromise in terms of simplicity, robustness, equity and efficiency.  相似文献   

8.
赵吕权  朱道弘  曾杨 《昆虫学报》2012,55(9):1037-1045
丽斗蟋Velarifictorus ornatus具有明显的翅二型现象, 长翅型与短翅型雌虫的卵巢和飞行肌存在着生理权衡。本研究分别应用蒽酮比色法、 硫代磷酸香草醛法、 考马斯亮蓝染液对羽化后10 d内两型雌虫飞行肌与卵巢内糖原、 总脂及蛋白质含量进行了定量分析。结果表明: 成虫羽化后10 d内, 两型雌虫体重无明显差异(P>0.05), 但短翅型雌虫怀卵量明显多于长翅型雌虫, 而人工脱翅能够促进长翅型雌虫怀卵量增加(P<0.05)。短翅型雌虫飞行肌内蛋白质、 糖原及总脂含量在成虫羽化后10 d内无明显变化, 但长翅型雌虫飞行肌内蛋白质在成虫羽化后3 d时达到最大值564.4±87.5 μg/♀, 糖原与总脂含量分别于羽化后第5天达到最大值85.2±21.7 μg/♀和5 284.7±1 267.4 μg/♀。然后开始下降, 各实验处理天数内, 长翅型雌虫飞行肌内蛋白质、 糖原及总脂含量都显著多于短翅型雌虫(P<0.05)。相反, 各处理天数内, 短翅型雌虫卵巢内蛋白质、 糖原及总脂含量则明显多于长翅型雌虫(P<0.05), 同时虫龄对蛋白质、 糖原及总脂在两型雌虫飞行肌与卵巢内分配也产生明显影响(P<0.05)。人工脱翅能够促进长翅型雌虫卵巢内蛋白质、 糖原及总脂含量增加, 同时诱导飞行肌内蛋白质、 糖原及总脂含量降低, 其中总脂含量在脱翅后10 d时降为2 394.9±1 461.8 μg/♀, 只有最大值的一半, 而与短翅型雌虫相似(P>0.05), 表明总脂为丽斗蟋飞行的主要能源物质。外用保幼激素Ⅲ能够促进长翅型雌虫卵巢内蛋白质、 糖原及总脂含量增加(P<0.05), 但对飞行肌内三者含量无明显影响(P>0.05), 外用早熟素Ⅰ对短翅型雌虫卵巢内蛋白质、 糖原及总脂含量亦无明显影响(P>0.05)。上述结果表明, 丽斗蟋长翅型雌虫首先将获得的资源用于发育飞行所需的飞行肌, 短翅型雌虫则首先将所获得的资源用于发育繁殖所需的卵巢, 但长翅型雌虫飞行肌与卵巢间的资源分配方式受保幼激素的影响。  相似文献   

9.
Abstract. Selection for the capacity for prolonged tethered flight in Spodoptera exempta resulted in heavier moths, with significantly larger abdominal glyceride glycerol contents in females of two flight-selected strains (87% and 49% higher than in the comparable non-selected strain) and in males of one of them (80% higher). All flight-selected strains contained individuals of both sexes with very high abdominal glyceride levels. There was no significant relationship between abdominal total glyceride glycerol after flight and flight duration for non-selected moths, but an inverse linear relationship was evident in both sexes from a flight-selected strain. Oxygen consumption during tethered flights by flight-selected moths ranged from 28.2 to 56.6 ml O2g-1h-1.
Using these and previous data, notional energy budgets were calculated to account for flight, reproduction and resting metabolism for non-selected and flight-selected S. exempta flown on the flight balances and provided thereafter with distilled water. The results confirm the trade-off between flight and reproduction reported by Gunn et al. (1989). A similar approach using data for two non-selected strains from the field in Kenya indicated genetic variation in migratory potential, reflected both in pre-reproductive period and resources available for flight. We conclude that elevated glyceride levels are a component of the migratory syndrome in S. exempta and that this is the major factor underlying the curvilinear relationship between flight duration and fecundity obtained by Gunn et al. (1989).  相似文献   

10.
The environment where an embryo develops can be influenced by components of maternal origin, which can shape offspring phenotypes and therefore maternal fitness. In birds that produce more than one egg per clutch, females differ in the concentration of components they allocate into the yolk along the laying sequence. However, identification of processes that shape female yolk allocation and thus offspring phenotype still remains a major challenge within evolutionary ecology. A way to increase our understanding is by acknowledging that allocation patterns can differ depending on the level of analysis, such as the population versus the among‐female (within‐population) level. We employed mixed models to analyze at both levels the variation in allocation along the laying sequence of four steroid hormones, three antioxidants, and four groups of fatty acids present in the egg yolks of wild great tits Parus major. We also quantified repeatabilities for each component to study female consistency. At a population level, the concentrations/proportions of five yolk components varied along the laying sequence, implying that the developmental environment is different for offspring developing in first versus last eggs. Females varied substantially in the mean allocation of components and in their plasticity along the laying sequence. For most components, these two parameters were negatively correlated. Females were also remarkably repeatable in their allocation. Overall, our data emphasize the need to account for female variation in yolk allocation along the laying sequence at multiple levels, as variation at a population level is underpinned by different individual patterns. Our findings also highlight the importance of considering both levels of analysis in future studies investigating the causes and fitness consequences of yolk compounds. Finally, our results on female repeatability confirm that analyzing one egg per nest is a suitable way to address the consequences of yolk resource deposition for the offspring.  相似文献   

11.
In dioecious species, females typically allocate more resources to reproduction and incur greater costs of reproduction than males. In gynodioecious species, sex-based differences in reproductive allocation (RA) and costs have been less studied. Such knowledge, however, is relevant to address how females establish and increase in frequency in populations. We examine RA and reproductive costs by comparing fruit set, the proportion of biomass allocated to reproduction, and the responses of fruit set and vegetative growth to shoot defoliation in females and hermaphrodites in gynodioecious Leucopogon melaleucoides. Relative to hermaphrodites, females exhibited a two-fold fruit set advantage. Female fruit set increased proportionately with flower number, but hermaphrodite fruit set was reduced on plants with more flowers. Sex-based differences in allocation to other traits were small. Thus, female RA at flowering was similar to hermaphrodite RA, but was 1.4-fold greater at fruiting. Relative to controls, defoliation reduced fruit set and the percentage of shoots that produced new vegetative growth similarly in both sexes. However, females had a lower proportion of shoots with new growth overall. Further, defoliation on females reduced the dry mass of new growth by 44% compared with controls, whereas hermaphrodites were not affected. These results indicate a trade-off between reproduction and vegetative growth, and greater female costs of reproduction, particularly under resource-limiting conditions. In the absence of compensatory traits to offset higher female reproductive costs, such trade-offs have the potential to retard the spread of females in gynodioecious populations.  相似文献   

12.
Vegetative reproduction is a very common alternative by which plants can contribute to the next generations. There are many considerations predicting which mode of reproduction, vegetative or sexual, should be favored and numerous experimental studies to verify them. However, the results are inconsistent especially when the effect of plant density is considered. I apply here a dynamic optimization model to predict the rate of vegetative and sexual reproduction in plants as a response to changes in the local plant density. The population is assumed to occupy a heterogeneous environment consisting of patches in which growth and reproduction of plants are possible and unfavorable space between them. As the environment is globally stable, the seeds, which can disperse without restriction, exhibit a constant recruitment rate. The ramets are assumed to settle only within the patch of the mother plant. The rate of ramet production effects local density, which in turn determines ramet recruitment. The optimal strategy maximizes the expected lifetime genetic contribution, realized via both vegetative and sexual reproduction. The solutions obtained under these assumptions are dualistic. The model predicts that different approaches applied in studying the effect of ramet density should give opposite outcomes. When the comparison is between patches in natural populations, a positive relationship between relative ramet allocation and density is expected. When the density is experimentally manipulated or its effect is analyzed across different successional stages, a negative relationship should be found. The results seem to be confirmed by empirical studies.  相似文献   

13.
Abstract Although the potential impacts of rising water tables and secondary salinization on agricultural land in southern Australia have been recognized for some time, it is only recently that the impacts on native vegetation have been considered. Despite the likely extent and severity of the problem, no comprehensive approach to assessing the impact of salinity upon native vegetation has been attempted to date. In the present paper, we discuss the causes and impacts of rising water tables and dryland salinity, assess the levels of risk in different ecosystem types and consider the possibilities for the maintenance of biodiversity and ecosystem function in vegetation at risk. We examine the salinity risk to woodland vegetation in the Western Australian (WA) wheatbelt, and consider both broad‐scale context and finer‐scale variation within individual patches of vegetation. From this information, we develop a set of conceptual models of the potential impacts of shallow saline water tables on ecosystem structure and processes in remnant vegetation in agricultural areas, particularly in the WA wheatbelt. First, we suggest that fine‐scale variability in surface topography and soil characteristics may play an important role in limiting the impacts of rising saline water tables. The outcome will depend on the interaction of the heterogeneity of the impact, species distribution in relation to small‐scale environmental heterogeneity and variation in species response to hydrological change. Second, we suggest that shallow saline water tables can be considered to cause an ‘edge effect’, which moves inwards from the edge of remnants of native vegetation. Finally, we consider how saline surface flows exacerbate the effects of shallow saline water tables and hasten vegetation decline in remnant areas. We put these models forward as hypotheses to be tested in different situations. We contrast the situation of secondary salinization in Australian vegetation with that of naturally saline systems in Australia and elsewhere, and suggest that these systems may provide important signposts toward developing management approaches for vegetation at risk. In conclusion, we consider the need to set priorities for the protection and restoration of natural vegetation at risk from altered hydrology, based on an assessment of relative threat and probability of persistence or recovery. We highlight the urgency for action that protects native vegetation from the increasing risks of rising water tables.  相似文献   

14.
Organisms must make important decisions on how to allocate resources to reproduction. We investigated allocation decisions in the social wasp Vespula maculifrons to understand how social insects make reproductive choices. We first determined how annual colonies apportioned resources to growth and reproduction by analysing developing brood. In contrast to expectations, colonies invested in both growth (workers) and reproduction (males) simultaneously. In addition, colonies showed evidence of producing males in pulses and reversing their reproductive choices by decreasing investment in males late in the season. This reversal is consistent with theory suggesting that colonies decrease production in males if fitness of late emerging males is low. To further investigate reproductive decisions within colonies, we determined if the male mates of multiply-mated queens varied in their reproductive success over time. Sperm use by queens did vary over time suggesting that male success may depend on sperm clumping within the female reproductive tract. Finally, we tested if colony sex ratio conformed to expectations under kin selection theory that nestmate relatedness would positively correlate with investment in new queens if workers controlled sex allocation. Surprisingly, the proportion of queens produced by colonies was negatively correlated with nestmate relatedness, suggesting that allocation may be shaped by advantages arising from increased genetic diversity resulting from multiple mating by queens. Overall, our study suggests that the reproductive decisions of colonies are flexible and may depend both on environmental cues arising from energetic needs of the colony and genetic cues arising from mating behaviours of queens.  相似文献   

15.
Many of the flowers produeed bv a plant fail to mature seeds despite effective pollination. The role of inflorescence architecture governing patterns of abortion in plants has been underestimated. 1 he inflorescence of Echium vulgare L. comprises a raceme bearing lateral inflorescences, each of which is cymosc. Within each cyme, there is a correlation between the proximity of a flower to the main axis and its order of flowering; and (lie probability of it maturing seeds. These findings appear to result from a decrease in the availability of maternal resources as the flowering period progresses. No relationship could be shown between the position of the cyme on the main inflorescence and the number of seeds set per flower although position was correlated with the length of the cyme, the number of (lowers and the length of the subtending bract. The mctamcric units of E. vulgare appear to function largely independently in their assimilation of resources. Larger cymes not only bear more flowers, but also draw on a larger area of photosynthetic tissue for resources. This hypothesis is supported by the removal of the bract or of part of the cyme at the onset of flowering; cymes without bracts mature fewer ovules than controls while decapitated cymes mature a greater proportion of ovules.  相似文献   

16.
17.
The classical model of colony dynamics developed by Macevicz and Oster predicts that optimal colony fitness in annual eusocial insects is achieved by a bang-bang strategy of reproduction: exclusive production of workers (ergonomic phase) followed by exclusive production of sexuals (reproductive phase). We propose an alternative model that assumes colony development in discrete broods and a limited overall investment potential of the queen. Based on the costs for producing eggs, workers, and sexuals and efficiency of individuals we predict the optimal number of workers and sexuals in the colony for each brood of the colony cycle that maximizes overall colony fitness. To link our model assumptions to the real world we chose model parameters according to field data of the halictid bee Lasioglossum malachurum. However, our model is representative of a large number of species with an annual life cycle and with discrete broods. Our model shows that the optimal partitioning of resources, i.e. the optimal workers/sexuals ratio depends on rearing cost for sexuals as well as productivity of workers but not on the queens’ total investment, egg cost, or rearing cost for workers. In complete accordance to Macevicz and Oster we predict a bang-bang reproduction strategy despite the differences in the basic assumptions. Potential deviations from this strategy and transitions from social to solitary breeding are discussed in the framework of our model. Received 31 October 2006; revised 29 March 2007; accepted 17 April 2007.  相似文献   

18.
Resource allocation, as well as the tradeoffs among different reproductive components, plays an important role in the adaptability of plants to different environments. The hybrid may exhibit a higher adaptability in life history in heterogeneous environments because of the genetic variation derived from its parents. In this study, we exploited three levels of water depths and two types of sediments to investigate the resource allocation pattern of the first generation of the natural hybrid Potamogeton ×intortifolius compared to its parents P. wrightii and P. perfoliatus. We also measured the ramet survivorship and the seed set of the hybrid P. ×intortifolius. Our results showed that P. ×intortifolius had higher ramet survival than its parents at 1.5-m water depth on clay sediment. The possible tradeoffs showed that in P. ×intortifolius the tradeoff pattern between sexual and clonal reproduction was more pronounced in limiting environments. The individuals allocated more resources to sexual reproduction when the environment was limiting, which might confer a higher ability to utilize resources, to produce offspring and to found new populations. Although the seed set of P. ×intortifolius was lower than its parents, it had a higher ability to increase its seed set when the environment was limiting (sandy sediment) than its parents, which might benefit its future survival. These results indicated that the F1 hybrid P. ×intortifolius was more able to adapt to limiting environments than one or both of its two parental taxa.  相似文献   

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