In this study, complex dynamics of Briggs–Rauscher reaction system is investigated analytically and numerically. First, the Briggs–Rauscher reaction system is reduced into a new nonlinear parametric oscillator. The Melnikov method is used to derive the condition of the appearance of horseshoe chaos in the cases ω = Ω and ω ≠ Ω. The performed numerical simulations confirm the obtained analytical predictions. Second, the prediction of coexisting attractors is investigated by solving numerically the new nonlinear parametric ordinary differential equation via the (...) fourth-order Runge–Kutta algorithm. As results, it is found that the new nonlinear chemical system displays various coexisting behaviors of symmetric and asymmetric attractors. In addition, the system presents a rich variety of bifurcations phenomena such as symmetry breaking, symmetry restoring, period doubling, reverse period doubling, period-m bubbles, reverse period-m bubbles, intermittency, and antimonotonicity. On the contrary, emerging chaotic band attractors and period-1, period-3, period-9, and period-m bubbles routes to chaos occur in this system. (shrink)

In this paper, we give an example of a complete computable infinitary theory T with countable models ${\mathcal{M}}$ and ${\mathcal{N}}$ , where ${\mathcal{N}}$ is a proper computable infinitary extension of ${\mathcal{M}}$ and T has no uncountable model. In fact, ${\mathcal{M}}$ and ${\mathcal{N}}$ are (up to isomorphism) the only models of T. Moreover, for all computable ordinals α, the computable ${\Sigma_\alpha}$ part of T is hyperarithmetical. It follows from a theorem of Gregory (JSL 38:460–470, 1972; Not Am Math Soc 17:967–968, 1970) (...) that if T is a Π 1 1 set of computable infinitary sentences and T has a pair of models ${\mathcal{M}}$ and ${\mathcal{N}}$ , where ${\mathcal{N}}$ is a proper computable infinitary extension of ${\mathcal{M}}$ , then T would have an uncountable model. (shrink)

A new approach to landscape ecology involves the application of the eco-field hypothesis and the General Theory of Resources. In this study, we describe the putative eco-field of bark beetles as a spatial configuration with a specific meaning-carrier for every organism-resource interaction. Bark beetles are insects with key roles in matter and energy cycles in coniferous forests, which cause significant changes to forestry landscapes when outbreaks occur. Bark beetles are guided towards host trees by the recognition of semiotic signals using (...) a specific eco-field. These signals mainly comprise a group of scents, which are called the odourtope. Their interactions with other organisms occur by sharing relevant information from the eco-field networks in the forest ecosystem. The eco-field networks modulate the expansion of the realized semiotic niche of the bark beetle towards the potential semiotic niche. Moreover, the niche construction process can be initiated by interchanging signals among species living in the same place, where these signals allow the exploitation of the required resources. If different organisms are interdependent on signals in eco-field networks, then this process may result in the establishment of mutualistic relationships. This is an example of how evolutionary processes are initiated by the recognition of signals in a network of eco-fields. (shrink)

Background: Issues concerning legislation and regulation with respect to the role of nurses in euthanasia and physician-assisted suicide gave the Minister for Health reason to commission a study of the role of nurses in medical end-of-life decisions in hospitals, home care and nursing homes.Aim: This paper reports the findings of a study of the role of nurses in euthanasia and physician-assisted suicide, conducted as part of a study of the role of nurses in medical end-of-life decisions. The findings for hospitals, (...) home care and nursing homes are described and compared.Method: A questionnaire was sent to 1509 nurses, employed in 73 hospitals, 55 home care organisations and 63 nursing homes. 1179 responses were suitable for analysis. The questionnaire was pilot-tested among 106 nurses, with a response rate of 85%.Results: In 37.0% of cases, the nurse was the first person with whom patients discussed their request for euthanasia or physician-assisted suicide. Consultation between physicians and nurses during the decision-making process took place quite often in hospitals and nursing homes and less frequently in home care situations . In some cases , nurses administered the euthanatics.Conclusions: The results show substantial differences between the intramural sector and the extramural sector , which are probably linked to the organisational structure of the institutions. Consultation between physicians and nurses during the decision-making process needs improvement, particularly in home care. Some nurses had administered euthanatics, although this task is by law exclusively reserved to physicians. (shrink)

Objectives: To foster the development of a privacy-protective, sustainable cross-border information system in the framework of a European public health project. Materials and methods: A targeted privacy impact assessment was implemented to identify the best architecture for a European information system for diabetes directly tapping into clinical registries. Four steps were used to provide input to software designers and developers: a structured literature search, analysis of data flow scenarios or options, creation of an ad hoc questionnaire and conduction of a (...) Delphi procedure. Results: The literature search identified a core set of relevant papers on privacy. Technicians envisaged three candidate system architectures, with associated data flows, to source an information flow questionnaire that was submitted to the Delphi panel for the selection of the best architecture. A detailed scheme envisaging an “aggregation by group of patients” was finally chosen, based upon the exchange of finely tuned summary tables. Conclusions: Public health information systems should be carefully engineered only after a clear strategy for privacy protection has been planned, to avoid breaching current regulations and future concerns and to optimise the development of statistical routines. The BIRO project delivers a specific method of privacy impact assessment that can be conveniently used in similar situations across Europe. (shrink)

This paper calculates, in a precise way, the complexity of the index sets for three classes of computable structures: the class $K_{\omega _{1}^{\mathit{CK}}}$ of structures of Scott rank $\omega _{1}^{\mathit{CK}}$ , the class $K_{\omega _{1}^{\mathit{CK}}+1}$ of structures of Scott rank $\omega _{1}^{\mathit{CK}}+1$ , and the class K of all structures of non-computable Scott rank. We show that I(K) is m-complete $\Sigma _{1}^{1},\,I(K_{\omega _{1}^{\mathit{CK}}})$ is m-complete $\Pi _{2}^{0}$ relative to Kleen's O, and $I(K_{\omega _{1}^{\mathit{CK}}+1})$ is m-complete $\Sigma _{2}^{0}$ relative to O.

The following texts and comments are a supplement to ‘Democritus on Politics and the Care of the Soul’, CQ 39 , 307–31 . The Democritean fragments there were quoted only in translation; detailed commentary on them would have taken up too much space and clogged the argument. They make their appearance here in the same order as they did there, preceded by a thumb-nail résumé of that argument and of their place in it. Text, spelling and numbering is that of (...) the standard edition: H. Diels, W. Kranz, Die Fragmente der Vorsokratiker . Reference will also be made to collections by P. Natorp, Die Ethika des Demokritos , S. Y. Luria, Democritea and G. Ibscher, Demócrito y sus sentencias sobre ética y education , as well as to translations by V. E. Alfieri, Gli Atomisti , K. Freeman, Ancilla to the Presocratics and J. Barnes, Early Greek Philosophy. (shrink)

In Corp. Gloss. Lat. V. 435–490 Goetz published excerpts from the A A glossary. Further interesting items were published by C. Theander in Eranos XXIII 51–61, 167–176. The complete glossary is now being prepared for the press, and Professor W. M. Lindsay has kindly communicated to me some of the new items which may possibly contain quotations from classical authors. The most interesting of them is the following: MA 2 ‘Mabortia res quae ad pugnam pertinet unde moenia funduntur vel res (...) Martia.’. (shrink)

John Locke:When we set before our eyes a round globe of uniform colour, v.g. gold, alabaster or jet, it is certain that the idea thereby imprinted in our mind is of a flat circle, variously shadowed, with several degrees of light and brightness coming to our eyes. But we having, by use, been accustomed to perceive what kind of appearance convex bodies are wont to make in us, what alterations are made in the reflections of light by the difference of (...) the sensible figures of bodies: the judgment presently, by an habitual custom, alters the appearances into their causes.H.H. Price:…. a distant hillside which is full of protuberances, and slopes upwards at quite a gentle angle, will appear flat and vertical….. This means that the sense-datum, the colour expanse which we sense, actually is flat and vertical. (shrink)

The complex hexaploid wheat genome offers many challenges for genomics research. Expressed sequence tags facilitate the analysis of gene-coding regions and provide a rich source of molecular markers for mapping and comparison with model organisms. The objectives of this study were to construct a high-density EST chromosome bin map of wheat homoeologous group 2 chromosomes to determine the distribution of ESTs, construct a consensus map of group 2 ESTs, investigate synteny, examine patterns of duplication, and assess the colinearity with rice (...) of ESTs assigned to the group 2 consensus bin map. A total of 2600 loci generated from 1110 ESTs were mapped to group 2 chromosomes by Southern hybridization onto wheat aneuploid chromosome and deletion stocks. A consensus map was constructed of 552 ESTs mapping to more than one group 2 chromosome. Regions of high gene density in distal bins and low gene density in proximal bins were found. Two interstitial gene-rich islands flanked by relatively gene-poor regions on both the short and long arms and having good synteny with rice were discovered. The map locations of two ESTs indicated the possible presence of a small pericentric inversion on chromosome 2B. Wheat chromosome group 2 was shown to share syntenous blocks with rice chromosomes 4 and 7. (shrink)

In response to a suggestion in the Class. Rev. , the two MSS. of the Liber Glossarum preserved at Tours have recently been examined. Since they had not been seen by Goetz when he published his excerpts, the following short descriptions may be added to the introduction of Vol. V. of the Corpus Glossariorum Latinorum: 1. Tours, Bibliothèque de Ville, MS. No. 850; end of the ninth century; foll. 493, of which 1, 491, 492 are mere corners; cmm. 49 by (...) 29. The last item is an Isidore gloss, Zatenen.-gemmam. Gaps due to loss of folia occur between Abiectus and Abdolet; Dextera manus and Dialogus; Faber and Impulitum; Res diuinae and Samsacus. There are no corrections except between folia 197 and 300, where a thirteenth-century hand has checked the MS. by means of another copy of the Lib. Gloss. The items are drawn up in two columns, and the alphabetical arrangement agrees for the most part with that of Vat. Pal. lat. 1773. Marginal indications of the sources of the items are numerous except between Profanum and Remeantes; where two or three neighbouring items come from the same source, the marginal mark is repeated; and towards the end of the MS., where the scribe takes to writing two items in the same line, the indication is also carefully transferred. This is important in view of Goetz' theory that the source of an unlabelled item is that given by the last preceding label. (shrink)

A total of 1918 loci, detected by the hybridization of 938 expressed sequence tag unigenes from 26 Triticeae cDNA libraries, were mapped to wheat homoeologous group 4 chromosomes using a set of deletion, ditelosomic, and nulli-tetrasomic lines. The 1918 EST loci were not distributed uniformly among the three group 4 chromosomes; 41, 28, and 31% mapped to chromosomes 4A, 4B, and 4D, respectively. This pattern is in contrast to the cumulative results of EST mapping in all homoeologous groups, as reported (...) elsewhere, that found the highest proportion of loci mapped to the B genome. Sixty-five percent of these 1918 loci mapped to the long arms of homoeologous group 4 chromosomes, while 35% mapped to the short arms. The distal regions of chromosome arms showed higher numbers of loci than the proximal regions, with the exception of 4DL. This study confirmed the complex structure of chromosome 4A that contains two reciprocal translocations and two inversions, previously identified. An additional inversion in the centromeric region of 4A was revealed. A consensus map for homoeologous group 4 was developed from 119 ESTs unique to group 4. Forty-nine percent of these ESTs were found to be homoologous to sequences on rice chromosome 3, 12% had matches with sequences on other rice chromosomes, and 39% had no matches with rice sequences at all. Limited homology was found between wheat ESTs on homoeologous group 4 and the Arabidopsis genome. Forty-two percent of the homoeologous group 4 ESTs could be classified into functional categories on the basis of blastX searches against all protein databases. (shrink)

F. H. George is Professor of Cybernetics at Brunel University in England. His book comprises eight chapters originally developed as lectures for a non-specialist audience. He points out the position of computer science among the sciences, explains its aims, procedures, and achievements to date, and speculates on its long-term implications for science in particular and society in general. Among the topics discussed are biological simulation and organ replacement, automated education, and the new philosophy of science. Each chapter concludes with a (...) brief summary. George's treatment of the technical details of his speciality is both illuminating and readable, thus serving as an excellent primer on one of the new technology's most important components. His wider forays into philosophy, economics, sociology, and religion are less happy, however; and unfortunately they take up a large part of the text. In general, they reveal that George identifies the methods of human advancement with the methods of the natural sciences in an equation whose rigidity would make even B. F. Skinner blush. Yet, the reader cannot claim that he was not forewarned; for in the introduction, D. J. Stewart, Chairman of the Rationalist Press Association, suggests that the current "swing of interest among young people away from the physical and biological sciences and towards the behavioural and social sciences... represents a symptom of disillusionment with science and technology and an attempted escape into irrationality."--J. M. V. (shrink)

Dr. G. S. Kirk suggested that the last line here referred to ‘a fantastically ithyphallic bridegroom’. Professor Lloyd-Jones , while professing uncertainty as to the rightness of this suggestion, thought it ‘quite likely’, and adduced in support of it a story from Tzetzes on Lycophron 1378 , a story told also, but in different words, in the Etymologicum Magnum s.v. , and containing in this second version the words ‘used in just the sense which Dr. Kirk ascribed to it in (...) Sappho’. (shrink)

David Rosenthal’s anthology is a valuable collection of readings. There is no dross in this book: each article is both an excellent philosophical composition in its own right and a marked stage in the development of the relatively young discipline, the philosophy of mind. Of the five sections of the book the first two are introductory; one historical the other problematic. The first section contains statements on classical materialism by Descartes, Spinoza, and Hobbes. The Descartes selections include passages from his (...) correspondence with Newcastle and Henry Moore. These clarify his veiled attack on Montaigne’s attempt to mitigate the differences between man and beast in Part V of the Discourse. Along with excerpts from Part V and Meditation VI the letters leave a coherent impression of the way Descartes handles "materialism." In the second part we are given the familiar statement of the identity thesis by Smart along with two early articles by Shaffer and Cornman, which, at the time overlooked, are significant forecasts of problems that most identity theorists are only today recognizing as problems. For instance, Cornman’s suggestion that the first project for the identity theorist is to "develop further the concept of a category" has attracted close attention only in the last few years. (shrink)

Context. The identification of the sources that reionized the Universe and their specific contribution to this process are key missing pieces of our knowledge of the early Universe. Faint star-forming galaxies may be the main contributors to the ionizing photon budget during the epoch of reionization, but their escaping photons cannot be detected directly due to inter-galactic medium opacity. Hence, it is essential to characterize the properties of faint galaxies with significant Lyman continuum photon leakage up to z 4 to (...) define indirect indicators allowing analogues to be found at the highest redshift. Aims. Long gamma-ray bursts explode typically in star-forming regions of faint, star-forming galaxies. Through LGRB afterglow spectroscopy it is possible to detect directly LyC photons. Our aim is to use LGRBs as tools to study LyC leakage from faint, star-forming galaxies at high redshift. Methods. Here we present the observations of LyC emission in the afterglow spectra of GRB 191004B at z = 3:5055, together with those of the other two previously known LyC-emitting LGRB, to determine their LyC escape fraction and compare their properties. Results. From the afterglow spectrum of GRB 191004B we determine a neutral hydrogen column density at the LGRB redshift of og =17:2 0:15, and negligible extinction. The only metal absorption lines detected are C iv and Si iv. In contrast to GRB 050908 and GRB 060607A, the host galaxy of GRB 191004B displays significant Ly emission. From its Ly emission and the non-detection of Balmer emission lines we constrain its star-formation rate to 1 SFR 4:7 M yr. 1. We fit the Ly emission with a shell model and find parameters values consistent with the observed ones. The absolute LyC escape fractions we find for GRB 191004B, GRB 050908 and GRB 060607A are of 0:35+0:10.0:11, 0:08+0:05.0:04 and :20+0:05.0:05, respectively. We compare the LyC escape fraction of LGRBs to the values of other LyC emitters found from the literature, showing that LGRB afterglows can be powerful tools to study LyC escape for faint high-redshift star-forming galaxies. Indeed we could push LyC leakage studies to much higher absolute magnitudes. The host galaxies of the three LGRB presented here have all M1600 >.19:5 mag, with the GRB 060607A host at M1600 >.16 mag. LGRB hosts may therefore be particularly suitable for exploring the ionizing escape fraction in galaxies that are too faint or distant for conventional techniques. Furthermore the time investment is very small compared to galaxy studies. (shrink)

With volume 5 the publication of the actual text of Henry's fifteen Quodlibetal Questions begins. Macken's edition is preceded by a valuable introduction, which itself commences with discussions of Henry's life and writings. Macken then surveys the manuscripts containing Quodlibet I and explains in detail the procedure he has adopted in reconstituting the text and the editing techniques he has employed. As he points out, Quodlibet I was given its definitive written form by Henry himself, and is not a mere (...) report drawn up by someone else who would have been present at its oral presentation. It should here be recalled that the Quodlibetal Question developed in Parisian University circles in the course of the thirteenth century as a distinctive literary genre of philosophical and theological writing. The Quodlibets themselves as we have them in written form reflect their origins in those special public oral sessions which were held twice a year in the Theology Faculty, and at which certain Masters would open themselves to questions from one and all about any appropriate topic. After this evidently taxing exercise, a Master would have the right to readdress himself to the questions that had been raised on some following day when meeting with his own students. By then he would have introduced some kind of order into the various topics originally proposed for discussion. And at some subsequent time, probably during the course of the next year, he would release them for publication, but only after having carefully revised them. As one might expect, the very nature of such an exercise opened the way for consideration of a bewildering variety of topics ranging widely over areas such as speculative and moral theology, metaphysics, natural philosophy, moral philosophy, and canon law. This variety is clearly reflected in the 42 questions examined in Henry's first Quodlibet. Thus one finds him here considering questions treating of Trinitarian theology, the hypostatic union, unicity vs. plurality of substantial form in man, Eucharistic theology, the possiblity of an eternally created universe, the relationship between essence and existence in creatures, and the possibility that prime matter could be sustained in existence by God apart from any substantial form. Questions are also raised relating to the nature of the soul both in its separated state and in its state of union with the body, and the relative priorities of intellect and will and their interrelationship in the act of choice. Finally, a host of other topics of less immediate interest to philosophers are also examined, such as the fate of infants who die without baptism, confessional jurisdiction, the guilt of a teacher who is primarily concerned with his own glory, etc. At the risk of oversimplification, certain positions defended by Henry in this Quodlibet will be mentioned because of their interest to students of metaphysics. In q. 4 he leaves open the possibility of defending unicity of substantial form in man. In qq. 7-8 he eliminates the possibility that any creature could have existed from eternity and, therefore, the possibility of an eternally created universe. In q. 9 he rejects real distinction between essence and existence in creatures and defends his well known "intentional" distinction between them. Here too he has already developed his unusual view of the essential being enjoyed by creatures insofar as they are objects of God's knowledge and have exemplar ideas in God. In q. 10 he denies that prime matter is pure potentiality and maintains that God could, if he should so choose, keep matter in existence without any substantial form. In q. 14 he defends the preeminence of the will over the intellect, and in a number of succeeding questions enters into intricate discussion of the interrelationship between reason and will in the act of choice. Perhaps these indications will be enough to give the reader some idea of the general direction of Henry's thought with respect to the topics in question. Anyone who has already examined earlier printed editions of Henry's Quodlibets will be delighted with Macken's superb edition of Quodlibet I. Apart from its great critical value, this volume is beautifully printed, handsomely bound, and appropriately indexed. This reviewer, for one, is eagerly awaiting the appearance of subsequent volumes in the series. All will be required reading for students of late thirteenth- and early fourteenth-century philosophy and theology.--J.F.W. (shrink)

OBJECTIVES: To investigate the need for hospital clinical ethics committees by studying the frequency with which ethical dilemmas arose, the perceived adequacy of the process of their resolution, and the teaching and training of staff in medical ethics. DESIGN: Interviews with individuals and three multidisciplinary teams; questionnaire to randomly selected individuals. SETTING: Two major London children's hospitals. RESULTS: Ethical dilemmas arose frequently but were resolved in a relatively unstructured fashion. Ethical concerns included: the validity of consent for investigations and treatment; (...) lack of children's involvement in consent; initiation of heroic or futile treatments; resource allocation. Staff expressed the need for a forum which would provide consultation on ethical issues, develop guidelines for good ethical practice, undertake teaching and training, and provide ethical reflection outside the acute clinical setting. CONCLUSION: Multidisciplinary, accountable and audited clinical ethics committees with predominantly advisory, practice development and educational roles could provide a valuable contribution to UK clinical practice and perhaps in other countries that have not developed hospital clinical ethics committees. (shrink)