In this paper the authors give a survey of biological phenomena , for which the term ‘differentiation’, used in the widest sense, has a meaningful application. The last chapter deals with some general aspects of differentiation and connected phenomena, such as polarity, symmetry, loss of potencies, dedifferentiation, redifferentiation, adifferentiation, regulation and integration.To prevent this article becoming too voluminous, the authors had to refrain from extending the treatment of differentiation to non-living matter and to human society.

Doctors are regularly confronted with requests for sterilisation of mentally handicapped people who cannot give consent for themselves. They ought to act in a medical vacuum because there doesn't exist a consensus about a model for decision making on this matter. In this article a model for decision making is proposed, based on a review of the literature and our own research data. We have attempted to select and classify certain factors which could enable us to arrive at an ethically (...) justifiable method of making a medical decision. In doing so we distinguish two major criteria: heredity and parenting competence, and six minor criteria: conception risk, IQ, age, personality, medical aspects and prognosis and finally support and guidance for the mentally handicapped person. The major criteria give rise to a "situation of necessity". In this situation the physician is confronted with a conflict of values and interests. The minor criteria are of an entirely different ethical order. They can only be considered once the major criteria have created a "situation of necessity". Ultimately it comes down to deciding whether the benefits of sterilisation outweigh the drawbacks and whether the means are appropriate to the end, where efficient contraception is the end and irreversible sterilisation is the means. (shrink)

Divided into eight sections, each with introductory essays, the selections offer rich and detailed insights into a diverse multinational philosophical landscape. Revealed in this pathbreaking work is the way in which traditional philosophical issues related to ethics, metaphysics, and epistemology, for instance, take on specific forms in Africa's postcolonial struggles. Much of its moral, political, and social philosophy is concerned with the turbulent processes of embracing modern identities while protecting ancient cultures.

The European Union welfare standardsfor intensively kept pigs have steadilyincreased over the past few years and areproposed to continue in the future. It isimportant that the cost implications of thesechanges in welfare standards are assessed. Theaim of this study was to determine theprofitability of rearing pigs in a range ofhousing systems with different standards forpig welfare. Models were constructed tocalculate the cost of pig rearing (6–95 kg) in afully-slatted system (fulfilling minimum EUspace requirements, Directive 91630/EEC); apartly-slatted system; a high-welfare,straw-based system (...) (complying with the UK-basedRoyal Society for the Prevention of Cruelty toAnimals, Freedom Food standards) and afree-range system. The models were also used toassess the consequences of potential increasesin space allowance, and to estimate the cost ofrearing pigs under organic standards.The cost of rearing pigs ranged from92.0 p/kg carcass weight (cw) and 94.6 p/kgcw forthe partly-slatted and fully-slatted systems,to 98.8 p/kgcw and 99.3 p/kgcw for the FreedomFood and free-range systems respectively. Whenspace allowance was increased by 60% to levelsin a recent proposal to revise pig welfareDirective (91/630/EEC), the rearing costs wereunchanged for the free-range system but rose by4.6 p/kgcw for the fully-slatted system. Rearingcosts under organic standards were 31% higherthan in the free-range system. These resultssuggest that improved pig welfare can beachieved with a modest increase in cost. (shrink)

From early sage philosophers to Leopold Senghor of Senegal and Steve Biko of South Africa, African thinking has challenged the way we think. As we enter a new millenium, the perspectives provided in this volume offer wise and refreshing alternatives to problems of self and society, culture, aesthetics, metaphysics and religion. Out of Africa always something new, and in these pages contemporary problems of cross-cultural cognition and post-coloniality are not only addressed, but also enacted. The reader witnesses the collision and (...) the coalescence of cultures in the writings of philosophers from Africa. (shrink)

The concept of joint action is at the core of numerous diverse research topics, including philosophical explorations of social action, studies of human dialogue, human-computer interaction, computer-supported collaborative work, multiagent systems, distributed artificial intelligence, distributed simulation, and contract law. It is therefore remarkable that so central a concept has received so little detailed analysis, in comparison with studies of individuals. However, in recent years, the study of joint action has begun to undergo more intense scrutiny, primarily from philosophers and researchers (...) in artificial intelligence. These two disciplines often address similar topics but with different motivations, methodologies, tools, and criteria for success. Although this paper is inspired by philosophical work, it is squarely motivated by the concerns of building intelligent systems that are capable of collaborative behavior, either with a user, or with other such systems. Still, we hope that the paper sheds light on philosophical issues, and treats the subject of joint action at a sufficiently precise level to be illuminating of problems that any philosophical account needs to confront. (shrink)

The use of the Quality Adjusted Life-Year (QALY) as a measure of the benefit obtained from health care expenditure has been attacked on the ground that it gives a lower value to preserving the lives of people with a permanent disability or illness than to preserving the lives of those who are healthy and not disabled. The reason for this is that the quality of life of those with illness or disability is ranked, on the QALY scale, below that of (...) someone without a disability or illness. Hence we can, other things being equal, gain more QALYs by saving the lives of those without a permanent disability or illness than by saving the lives of those who are disadvantaged in these ways. But to do so puts these disadvantaged people under a kind of double jeopardy. Not only do they suffer from the disability or illness, but because of it, a low priority is given to forms of health care that can preserve their lives. This, so the objection runs, is unjust or unfair. This article assesses this objection to the use of QALYs as a basis for allocating health care resources. It seeks to determine what is sound in the double jeopardy objection, and then to show that the defender of QALYs has an adequate response to it. (shrink)

The focus of this study was to analyze the content, distribution, and comparative genome relationships of 996 chromosome bin-mapped expressed sequence tags accounting for 2266 restriction fragments on the homoeologous group 3 chromosomes of hexaploid wheat. Of these loci, 634, 884, and 748 were mapped on chromosomes 3A, 3B, and 3D, respectively. The individual chromosome bin maps revealed bins with a high density of mapped ESTs in the distal region and bins of low density in the proximal region of the (...) chromosome arms, with the exception of 3DS and 3DL. These distributions were more localized on the higher-resolution group 3 consensus map with intermediate regions of high-mapped-EST density on both chromosome arms. Gene ontology classification of mapped ESTs was not significantly different for homoeologous group 3 chromosomes compared to the other groups. A combined analysis of the individual bin maps using 537 of the mapped ESTs revealed rearrangements between the group 3 chromosomes. Approximately 232 of the consensus mapped ESTs matched sequences on rice chromosome 1 and revealed large- and small-scale differences in gene order. Of the group 3 mapped EST unigenes ∼21 and 32% matched the Arabidopsis coding regions and proteins, respectively, but no chromosome-level gene order conservation was detected. (shrink)

A total of 944 expressed sequence tags generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat. EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and ID with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms (...) was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences, where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses. (shrink)