57 research outputs found
From Biology to Consciousness to Morality
Social animals are provisioned with prosocial orientations that operate to transcend self-interest. Morality, as used here, describes human versions of such orientations. We explore the evolutionary antecedents of morality in the context of emergentism, giving considerable attention to the biological traits that undergird awareness and our emergent human forms of mind. We suggest that our moral frames of mind emerge from our primate prosocial capacities, transfigured and valenced by our symbolic languages, cultures, and religions.
Portions of this article were given by Deacon in a paper at the forty-ninth annual conference of IRAS, “Is Nature Enough? The Thirst for Transcendence,” Star Island, New Hampshire, 27 July-3 August 2002
À propos de l’homme, ou comment repenser la sélection naturelle du langage humain
Il arrive qu’une complexité extrême mette le modèle de la sélection naturelle au défi d’expliquer quoi que ce soit. Depuis Darwin, l’aptitude humaine au langage est incessamment citée en exemple-type de ce cas de figure. Et ceux qui ont souligné les problèmes posés par cette faculté si spécifiquement humaine n’étaient pas tous des critiques du darwinisme. On sait l’argument avancé par Alfred Russel Wallace, co-instigateur de la théorie de la sélection naturelle, et réputé plus darwiniste que ..
Origins of Biological Teleology: How Constraints Represent Ends
To naturalize the concept of teleological causality in biology it is not enough to
avoid assuming backward causation or positing the existence of an inscrutable te-
leological essence like the élan vital. We must also specify how the causality of or-
ganisms is distinct from the causality of designed artifacts like thermostats or asym-
metrically oriented processes like the ubiquitous increase of entropy. Historically,
the concept of teleological causality in biology has been based on an analogy to the
familiar experience of purposeful action. This is experienced by us as a disposition
to achieve a general type of end that is represented in advance, and which regulates
the selection of efficient means to achieve it. Inspired by this analogy, to bridge
the gap between biology and human agency we describe a simple molecular pro-
cess called autogenesis that shows how two linked complementary self-organizing
processes can give rise to higher-order relations that resemble purposeful disposi-
tions, though expressed in terms of constraints on molecular processes. Because
the autogenic model is described in sufficient detail to be empirically realizable, it
provides a proof of principle demonstrating a simple form of teleological causality
Tri-partite complex for axonal transport drug delivery achieves pharmacological effect.
BACKGROUND: Targeted delivery of pharmaceutical agents into selected populations of CNS (Central Nervous System) neurons is an extremely compelling goal. Currently, systemic methods are generally used for delivery of pain medications, anti-virals for treatment of dermatomal infections, anti-spasmodics, and neuroprotectants. Systemic side effects or undesirable effects on parts of the CNS that are not involved in the pathology limit efficacy and limit clinical utility for many classes of pharmaceuticals. Axonal transport from the periphery offers a possible selective route, but there has been little progress towards design of agents that can accomplish targeted delivery via this intraneural route. To achieve this goal, we developed a tripartite molecular construction concept involving an axonal transport facilitator molecule, a polymer linker, and a large number of drug molecules conjugated to the linker, then sought to evaluate its neurobiology and pharmacological behavior. RESULTS: We developed chemical synthesis methodologies for assembling these tripartite complexes using a variety of axonal transport facilitators including nerve growth factor, wheat germ agglutinin, and synthetic facilitators derived from phage display work. Loading of up to 100 drug molecules per complex was achieved. Conjugation methods were used that allowed the drugs to be released in active form inside the cell body after transport. Intramuscular and intradermal injection proved effective for introducing pharmacologically effective doses into selected populations of CNS neurons. Pharmacological efficacy with gabapentin in a paw withdrawal latency model revealed a ten fold increase in half life and a 300 fold decrease in necessary dose relative to systemic administration for gabapentin when the drug was delivered by axonal transport using the tripartite vehicle. CONCLUSION: Specific targeting of selected subpopulations of CNS neurons for drug delivery by axonal transport holds great promise. The data shown here provide a basic framework for the intraneural pharmacology of this tripartite complex. The pharmacologically efficacious drug delivery demonstrated here verify the fundamental feasibility of using axonal transport for targeted drug delivery.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study
Purpose:
Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom.
Methods:
Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded.
Results:
The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia.
Conclusion:
We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes
A degenerative process underlying hierarchic transitions in evolution.
This paper describes an evolutionary process likely involved in hierarchic transitions in biological evolution at many levels, from genetics to social organization. It is related to the evolutionary process described as contingent neutral evolution (CNE). It involves a sequence of stages initiated by the spontaneous appearance of functional redundancy. This redundancy can be the result of gene duplication, symbiosis, cell-cell interactions, environmental supports, etc. The availability of redundant sources of biological functionality relaxes purifying selection and allows degenerative changes to accumulate in one or more of the duplicates, potentially degrading or otherwise fractionating its function. This degeneration will be effectively neutral so long as another maintains functional integrity. Sexual recombination can potentially sample different combinations of these sub functional alternatives, with the result that favorable synergistic interactions between independently degenerate duplicates will have a non-negligible probability of being uncovered. The expression of such a synergistic combinatorial effect will result in the irreversible degradation of any remaining autonomous functionality, thereby initiating selection to prevent breakup of co-dependency. This becomes relevant to the evolution of hierarchic transitions when two or more organisms reciprocally duplicate functions that each other requires. If the resulting relaxation of selection reliably persists for an extended evolutionary period it will tend to produce complementary degenerative effects in each organism, leading to their irreversible codependency and purifying selection to avoid loss of integrity of their higher order functional unity. This provides a partial inversion of Darwinian logic that explains how the potential costs of the loss of organism autonomy can be mitigated, enabling the incremental transition to a synergistic higher order unit of evolution
Evolutionary perspectives on language and brain plasticity.
Our understanding of speech and language disorders may be aided by information about the constraints and predispositions contributed by neural developmental processes. As soon as we begin to look at human neuroanatomy and development from a comparative perspective, it is possible to recognize a number of ways that human brains diverge from the general pattern of other ape and monkey brains. These divergences may offer clues to language evolution. Large-scale quantitative changes in the relative proportions of brain regions (as opposed to just overall expansion) offer some of the most obvious clues. Additional information about how axons are guided in their extensions to distant developmental targets and how competitive trophic processes sculpt these connections also provides a way to understand how gross quantitative changes in cell numbers could affect circuit organization and ultimately behavior. © 2000 by Elsevier Science Inc. Educational Objectives: The reader will learn how general principles of brain development have contributed to both human brain plasticity and the acquisition of the human capacity for speech
Language as an Emergent Function: Some Radical Neurological and Evolutionary Implications
Language is a spontaneously evolved emergent adaptation, not a formal computational system. Its structure does not derive from either innate or social instruction but rather self-organization and selection. Its quasi-universal features emerge from the interactions among semiotic constraints, neural processing limitations, and social transmission dynamics
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