A biomathematical model of a human operator’s falling asleep

Quantitative analysis of the transition from wakefulness to sleep and prediction of the moment when errors in professional activity appear because of a decrease in the arousal level require microinterval monitoring of falling asleep. A psychomotor test was developed that rapidly decreased the arousal level, which made it possible to record as many as 10–20 episodes of correct and erroneous activity within 40 min and isolate the periods electrophysiologically corresponding to wakefulness and brief sleep. Seventy subjects were tested, and 6700 fragments of recordings with correct and erroneous performance were analyzed. Analysis of the experimental data showed that the transition from wakefulness to sleep includes intermediate short and relatively long periods of wakefulness and sleep, whose durations are distributed according to the double exponential law. A mathematical model describing the time course of alternation of these four states of wakefulness and sleep predicts the probability of prolonged, potentially dangerous disturbances in operator activity because of microsleep as dependent on the initial state and individual characteristics of subjects. The results will be useful both for the development of devices monitoring and predicting changes in the physiological arousal level and for analysis of traffic and industrial accidents.     

Tetz’s theory and law of longevity

Here, we present new theory and law of longevity intended to evaluate fundamental factors that control lifespan. This theory is based on the fact that genes affecting host organism longevity are represented by subpopulations: genes of host eukaryotic cells, commensal microbiota, and non-living genetic elements. Based on Tetz’s theory of longevity, we propose that lifespan and aging are defined by the accumulation of alterations over all genes of macroorganism and microbiome and the non-living genetic elements associated with them. Tetz’s law of longevity states that longevity is limited by the accumulation of alterations to the limiting value that is not compatible with life. Based on theory and law, we also propose a novel model to calculate several parameters, including the rate of aging and the remaining lifespan of individuals. We suggest that this theory and model have explanatory and predictive potential to eukaryotic organisms, allowing the influence of diseases, medication, and medical procedures to be re-examined in relation to longevity. Such estimates also provide a framework to evaluate new fundamental aspects that control aging and lifespan.     

The derivation of D’Arcy Thompson’s theory of transformations from the theory of optimal design

It is shown informally that Cohn’s theory of Optimal Forms can be construed as a comparative theory, and that when this is done the celebrated theory of transformations of D’Arcy Thompson follows as a consequence. The implications of this type of theoretical foundation for the Thompson theory with regard to problems of comparative morphology are discussed, and some suggestions for the further implementation of the theory are described. This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under Contract No. AF 49(638)-917.     

A standard model of Alzheimer’s disease?

ABSTRACT

The recent Research Framework proposed by the US National Institute on Aging and the Alzheimer’s Association (NIA-AA) recommends that Alzheimer’s disease be defined by its specific biology rather than by non-specific neurodegenerative and syndromal features. By affirming markers of abnormal Aβ and tau proteins as the essential pathobiological signature of Alzheimer’s disease, the Framework tacitly reinforces the amyloid (Aβ) cascade as the leading theory of Alzheimer pathogenesis. In light of recent evidence that the cascade is driven by the misfolding and templated aggregation of Aβ and tau, we believe that an empirically grounded Standard Model of Alzheimer’s pathogenesis is within reach. A Standard Model can clarify and consolidate existing information, contextualize risk factors and the complex disease phenotype, identify testable hypotheses for future research, and pave the most direct path to effective prevention and treatment.     

Haeckel’s scientific monism as theory of history

Summary Recent research at the Haeckel Haus at the University of Jena goes far to confirm Haeckel’s role as an ideological progenitor of fascist ideology. This is true not only for Germany, but also for the birth of fascist thought in Italy and France. Haeckel’s Monism is the main inspiration for the origin of French and Italian fascism as well as other vital manifestations of modernist culture. In general, the history of science reveals more fully than any other theoretical approach, the roots of fascism as well as avant-garde modernism.     

How ubiquitous is adaptation? A critique of the epiphenomenist program

It is important to distinguish adaptation per se (adaptedness, or being adapted) from the more specific concept of adaptation for some function. Commonly used criteria for adaptation in either sense have limited applicability. There are, however, a number of widely applicable criteria for adaptation per se, such as several kinds of cost, low variation, the maintenance of integration, and the fitness distribution of mutations. Application of these criteria leads to the conclusion that adaptation is overwhelmingly prevalent for features of organisms. Neither the presence nor the absence of adaptation has a privileged status in inference. Effectively neutral evolution can occur on adaptive buttes while maintaining the same degree of adaptation, but it is likely to be relatively minor.

Do we need a ‘theory’ of development?

Edited by Alessandro Minelli and Thomas Pradeu, Towards a Theory of Development gathers essays by biologists and philosophers, which display a diversity of theoretical perspectives. The discussions not only cover the state of art, but broaden our vision of what development includes and provide pointers for future research. Interestingly, all contributors agree that explanations should not just be gene-centered, and virtually none use design and other engineering metaphors to articulate principles of cellular and organismal organization. I comment in particular on the issue of how to construe the notion of a ‘theory’ and whether developmental biology has or should aspire to have theories, which four of the contributions discuss in detail while taking opposing positions. Beyond construing a theory in terms of its empirical content (established knowledge about biological phenomena), my aim is to shift the focus toward the role that theories have for guiding future scientific theorizing and practice. Such a conception of ‘theory’ is particularly important in the context of development, because arriving at a theoretical framework that provides guidance for the discipline of developmental biology as a whole is more plausible than a unified representation of development across all taxa.     

A Metabolic Study of Huntington’s Disease

Background

Huntington’s disease patients have a number of peripheral manifestations suggestive of metabolic and endocrine abnormalities. We, therefore, investigated a number of metabolic factors in a 24-hour study of Huntington’s disease gene carriers (premanifest and moderate stage II/III) and controls.

Methods

Control (n = 15), premanifest (n = 14) and stage II/III (n = 13) participants were studied with blood sampling over a 24-hour period. A battery of clinical tests including neurological rating and function scales were performed. Visceral and subcutaneous adipose distribution was measured using magnetic resonance imaging. We quantified fasting baseline concentrations of glucose, insulin, cholesterol, triglycerides, lipoprotein (a), fatty acids, amino acids, lactate and osteokines. Leptin and ghrelin were quantified in fasting samples and after a standardised meal. We assessed glucose, insulin, growth hormone and cortisol concentrations during a prolonged oral glucose tolerance test.

Results

We found no highly significant differences in carbohydrate, protein or lipid metabolism markers between healthy controls, premanifest and stage II/III Huntington’s disease subjects. For some markers (osteoprotegerin, tyrosine, lysine, phenylalanine and arginine) there is a suggestion (p values between 0.02 and 0.05) that levels are higher in patients with premanifest HD, but not moderate HD. However, given the large number of statistical tests performed interpretation of these findings must be cautious.

Conclusions

Contrary to previous studies that showed altered levels of metabolic markers in patients with Huntington’s disease, our study did not demonstrate convincing evidence of abnormalities in any of the markers examined. Our analyses were restricted to Huntington’s disease patients not taking neuroleptics, anti-depressants or other medication affecting metabolic pathways. Even with the modest sample sizes studied, the lack of highly significant results, despite many being tested, suggests that the majority of these markers do not differ markedly by disease status.     

Global heterochromatin loss: A unifying theory of aging?

The aging field is replete with theories. Over the past years, many distinct, yet overlapping mechanisms have been proposed to explain organismal aging. These include free radicals, loss of heterochromatin, genetically programmed senescence, telomere shortening, genomic instability, nutritional intake and growth signaling, to name a few. The objective of this Point-of-View is to highlight recent progress on the “loss of heterochromatin” model of aging and to propose that epigenetic changes contributing to global heterochromatin loss may underlie the various cellular processes associated with aging.     

A critique of the methodology of Robert Redfield: ‘Folk culture’ and other concepts

The Raw and the Cooked. Claude Levi‐Strauss. Jonathan Cape 1970. 387 pp., ill., bibl. Price £3.5.0.

Folktales of Israel. Ed. by Dov Noy with the assistance of Dan Ben Amos. Transi, by Gene Baharav. The University of Chicago Press. Folktales of the World. Chicago 1963. 221 S. $ 4.00.

Politics of Social Research. An inquiry into the ethics and responsibilities of social scientists. Ralph L. Beals. Aldine Publishing Company. Chicago 1969. 228 pp.

African Stone Sculpture. Philip Allison. Percy Lund, Humphries &; Co., Ltd. London 1968. 71 pp. 99 pls. 3 maps. Price 56 s.

The Elementary Structures of Kinship. (Les Structures élémentaires de la Parenté). Claude Lévy‐Strauss. Rev. ed. translated from the French by James Harle Bell, John Richard von Sturmer and Rodney Needham, Editor. Beacon Press, Boston; Eyre &; Spottiswoode Ltd., London. 1969. 541 pp., 87 figs. Price $ 15.00.

Contes sous la Croix du Sud. Giselle de Goustine. (Les littératures populaires de toutes les nations. N.S., T. XIII). Editions G.‐P. Maisonneuve et Larose, Paris 1967. 208 pp.

La divination malgache par le sikidy. Raymond Decary avec la collaboration de Marcelle Urbain‐Faublée. Publications du centre Universitaire des Langues Orientales Vivantes, 6e série, vol. IX. Paul Geuthner, Paris 1970. 111 pp.

Über Lebensraum und Lebensformen des Frühsemiten. Joseph Henninger. Arbeitsgemeinschaft für Forschung des Landes Nordrhein‐Westfalen. Geisteswissenschaften, Heft G 151. Westdeutscher Verlag. Köln und Opladen 1968. 61 Seiten. Kart. DM 6.60.

Indianer von gestern, heute und morgen. Beobachtungen zum Kulturwandel in den Anden Boliviens. Hermann Trimborn. Kulturgeschichtliche Forschungen; 12. Band. Albert Limbach Verlag, Braunschweig 1968. 96 S., 104 Abb., 1 Karte. Preis DM 38:—.

Der Wandel ökonomischer Rollen bei den westlichen Dan in Liberia. Eberhard Fischer. Studien zur Kulturkunde, Band XXI. Franz Steiner Verlag, Wiesbaden. Wiesbaden 1967. 481 S. 4 Taf. 7 Abb. DM 66:—.

An Anthropological Bibliography of South Asia. Together with a Directory of Anthropological Field Research. Vol. III. 1960–64. Compiled by

Elizabeth von Fürer‐Haimendorf and Helen Kanitkar. Le Monde d'Outre‐Mer Passé et Présent, Quatrième Série. Bibliographies VIII. Editions Mounton &; Cie, Paris 1970. 562 pp. Price 193 F.

Man‐apes or Ape‐men? The Story of Discoveries in Africa. Sir Wilfrid E. Le Gros Clark. Holt, Rinehart and Winston, Inc., New York 1967. 150 pp., 33 fig., bibliography, index. Price $3.95.     

A specialist’s audit of aggregated occurrence records: An ‘aggregator’s’ perspective

A recent ZooKeys’ paper (Mesibov, 2013: http://www.pensoft.net/journal_home_page.php?journal_id=1&page=article&SESID=df7bcb35b02603283dcb83ee0e0af0c9&type=show&article_id=5111) has highlighted data quality issues in aggregated data sets, but did not provide a realistic way to address these issues. This paper provides an aggregator’s perspective including ways that the whole community can help to address data quality issues. The establishment of GBIF and national nodes (national aggregators) such as the Atlas of Living Australia (ALA) have integrated and exposed a huge diversity of biological observations along with many associated issues. Much of the admirable work by Mesibov (2013) was enabled by having the data exposed.Data quality, one of the highest priorities for GBIF, the national nodes and other aggregators, depends on both automatic methods and community experts to detect and correct data issues. Not all issues can however be automatically detected or corrected, so community assistance is needed to help improve the quality of exposed biological data. We do need to improve the infrastructure and associated processes to more easily identify data issues and document all changes to ensure a full record is permanently and publicly available.     

A quantum probability explanation for violations of ‘rational’ decision theory

Two experimental tasks in psychology, the two-stage gambling game and the Prisoner''s Dilemma game, show that people violate the sure thing principle of decision theory. These paradoxical findings have resisted explanation by classical decision theory for over a decade. A quantum probability model, based on a Hilbert space representation and Schrödinger''s equation, provides a simple and elegant explanation for this behaviour. The quantum model is compared with an equivalent Markov model and it is shown that the latter is unable to account for violations of the sure thing principle. Accordingly, it is argued that quantum probability provides a better framework for modelling human decision-making.