SEARCH · PubMed Health

Results for “social evolution”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

PubMed2004

The Prisoner's Dilemma and polymorphism in yeast SUC genes.

The SUC multigene family of the single-celled yeast Saccharomyces cerevisiae is polymorphic, with genes varying both in number and activity. All of the genes encode invertase, an enzyme that is secreted to digest sucrose outside of the cell. This communal endeavour creates the potential for individual cells to defect (cheat) by stealing the sugar digested by their neighbours without contributing the enzyme themselves. We measured the fitness of a defector, with a deleted suc2 gene, relative to an otherwise isogenic cooperator, with a functional SUC2 gene. We manipulated the level of social interaction within the community by varying the population density and found that the defector is less fit than the cooperator at low levels of sociality but more fit in dense communities. We propose that selection for antisocial cheating causes SUC polymorphism in nature. The infamous Prisoner's Dilemma game shows that social behaviour is generally unstable, and the success of both cooperation and defection can vary continuously in time and space. The variation in SUC genes reflects constant adaptation to an ever-changing biotic environment that is a consequence of the instability of cooperation. It is interesting that social interactions can have a direct effect on molecular evolution, even in an organism as simple as yeast.

Adaptation, Biological↗

PubMed1987

Perception and concern about sociocultural change and psychopathology in a Saudi Arabian sample.

The study presents data on 280 Saudi Arabian University students regarding their perception and concern about social-cultural changes in their society, and comparison of their scores on these variables with their responses on some psychopathology measures. All students were administered an interview schedule evaluating perception and concern (upset--not upset) about sociocultural changes, the Multiple Affect Adjective Check List, the Depression Symptomatology Scale, and a Symptom Inventory. Our results showed that: (1) Substantial numbers were aware of the social and cultural transformations in Saudi Arabia. However, Saudis were, on the whole, less upset about adverse social processes than comparative American samples; (2) depressive and other psychopathology symptoms were reported frequently, and (3) subjects who showed higher levels of concern about sociocultural changes obtained the lowest depression scores, indicating that those who were not upset by social transformation were generally not depressed. The relationship between psychopathology and perception of social nuances was discussed in light of the view that less depressed people are more capable of handling stresses related to personal processing of social variables.

Adult↗

PubMed2005

Harm reduction--the cannabis paradox.

This article examines harm reduction from a novel perspective. Its central thesis is that harm reduction is not only a social concept, but also a biological one. More specifically, evolution does not make moral distinctions in the selection process, but utilizes a cannabis-based approach to harm reduction in order to promote survival of the fittest. Evidence will be provided from peer-reviewed scientific literature that supports the hypothesis that humans, and all animals, make and use internally produced cannabis-like products (endocannabinoids) as part of the evolutionary harm reduction program. More specifically, endocannabinoids homeostatically regulate all body systems (cardiovascular, digestive, endocrine, excretory, immune, nervous, musculo-skeletal, reproductive). Therefore, the health of each individual is dependent on this system working appropriately.

Journal Article↗

PubMed2006

Evolving concepts in the measurement of treatment effects.

This is an interesting time in the evolution of clinical research, as the convergence of scientific, social, and technological advances influences the development of new measurement strategies and creates new challenges and opportunities in the evaluation of treatment outcomes. The purpose of this paper is to provide a brief overview of the forces of change influencing clinical research in general and measurement, specifically, discuss current challenges in the evaluation of treatment outcomes in chronic obstructive pulmonary disease and propose several areas for further research. Five key challenges are discussed: accuracy in the selection and measurement of endpoints; appropriate timing and recall; measurement efficiencies using aggregation techniques or item response theory; interpretation, including the debate concerning the minimal important difference; and the need for "real world" studies with real-world measures to understand treatment effectiveness. Each of these areas offers interesting challenges and opportunities for further development and research.

Biomedical Research↗

PubMedDate not supplied

[The deregulation of health care organizations in Argentina: what is next?].

This article presents the historical evolution of the main heath system in Argentina - The Social Works System (System de Obras Sociais - OS) focusing in the nineties, when were realized the main intents to reform this system. The article point out the difficulties on the health reforms implementation and the interest conflicts that emerged on the negotiation among government and trade unions who managed the system since its creation. The article also analyze the near future perspectives regarding the OS system.

Argentina↗

PubMed2002

[Contemporary university: a betrayed tradition?].

The current evolution of University is examined in parallel with the evolution of society. Society of uncertainty, crisis of the social actor, selective mechanisms of the elite, fundamental role of technical predominance and of economical processes are analyzed based on the "tradition" concept. The possibility of an authoritative comeback of the role of University is found in an active and articulated intervention of integration and cultural mediation, substantiating the bridge of tradition.

Cultural Characteristics↗

PubMed1994

[State influence on the health of the child].

"This article follows the major historical steps with respect to the protection of the child aged less than three years in France and in Canada over the course of a century. Analysis focuses first on the motives behind increased intervention by political leaders on behalf of the child; next on the protection of the welfare of the mother and child; and finally on the evolution of demographic characteristics, in relation with processes of social and geographic differentiation. A remarkable convergence is observed between the two countries, despite veritable differences in political pressures and actions, traceable back to certain common structural traits, and linked with emerging patterns of international exchanges favouring the modelling of a new culture regarding childhood." (SUMMARY IN ENG AND SPA)

Americas↗

PubMedDate not supplied

[Eye involvement in Hansen disease: evaluation in nursing consultations].

This is a quantitative, exploratory-descriptive study. It analyzed patients who suffered from Hansen's disease based on social-demographic data, clinic form and time of disease evolution. It identified ocular alterations, relating clinic form to the time of evolution of this illness. The sample was composed of a group 60 patients: 39 were men and 21 were women, 35 were tan, 19 were white and 6 were black. The examination of these patients included eye-lid muscular power, external structures, ocular mobility, cornea sensitiveness, tear production, field and visual accuracy. The clinic form was dimorphous (42); virchovian (13); undefined (3) and tuberculoid (2). Disease evolution was from 1 to 4 years in 42 of the patients. Regarding eye alterations there was a reduction of tear production (32); of eye-lid muscular power (12) and of cornea sensitiveness (10); hyperemia (13); lagophthalmos (8) and madarosis (7), mainly concentrated in the dimorphous form (43) and virchovian (15). The multibacillaries present more intense ocular problems and it was not possible to establish correlation between them and time of evolution.

Adult↗

PubMed2004

[Chronic obstructive pulmonary disease. Impact and exacerbations].

Chronic Obstructive Pulmonary Disease constitutes a medical and social problem of great magnitude. The progressive and chronic evolution of this disease is often worsened by periods when its symptoms increase, particularly coughing, dyspnea, and the quantity and purulence of a patient's spittle. These episodes during which symptoms increase are what we refer to as acute crises. The majority of these acute crises are produced by bronchial infections and they have an important effect on a patient's quality of life and on the evolution of a patient's illness.

Humans↗

PubMed1990

[Mechanisms and physiologic role of yawning].

As well as being present in all mammals, yawning occurs, at least in its mandibular component, in all vertebrates. The existence of pathological and pharmacologically induced yawning justifies study of this everyday ENT reflex. Its mechanism remains uncertain. The most likely hypothesis would seem to be stimulation of the reticular system of the brain-stem by signals originating in masseteric neuromuscular spindles sensitive to stretching. Serotoninergic inhibition from the dorsal raphe, a fall in hypothalamic dopaminergic inhibitory tone, followed by ocytocinergic hippocampal activation and then more diffuse cholinergic activation of cranial nerve motor nuclei seems likely. Various hormonal or socio-environmental influences can modify the activity of these different systems. The physiological consequences and the communicative value of yawning become more diversified with the phylogenetic evolution of the subject. Yawning appears to correspond to an alertness reflex which has acquired a paralinguistic value with evolution and may have a role in protection or social cohesion.

Animals↗

PubMed1981

Theory on prospect of population evolution processes.

This paper is aimed at investigating the dynamic process of population growth applied to population of the People's Republic of China. The discrete and continuous models of population evolution process are revised and adjusted to suit the social conditions of China. The relationship between two kinds of models is established. A series of new formulae of demographic indices are studied and defined as functions on the negative space of generalized solutions of the population equation. Based on survey data collected in China for recent years, the prospect of population growth according to different projections is offered for a one-hundred-year period from now on.

Demography↗

PubMed1993

Alcohol: the clinician's role in evaluating legal responsibility.

Alcohol-related misconduct poses a challenge for society, the legal system, and the medical profession. The debate is centered on alcohol abuse and the determination of responsibility for misbehavior. In assessing responsibility, the legal system often requests the expertise of the medical professional. The knowledgeable clinician can contribute to the just resolution of complex medico-legal cases. The best contribution considers medical facts in relation to the evolution of legal thinking. This article explores the historical, social, and legal approaches to alcohol-related misconduct. The article concludes with a discussion of a model clinical assessment.

Alcoholism↗

PubMedDate not supplied

[The nerve centers of the emotions].

The participation and the role of the brain formations in the genesis of emotional reactions of higher animals and man are discussed according to E.A. Asratian's concept of the nervous centre as a complex of brain structures, situated in different areas of the central nervous system, comprising the total morpho-functional unity and realizing a definite specific function. The data are given testifying that the frontal and temporal areas of the neocortex, hippocampus, amygdala and hypothalamus are correspondingly connected with reflecting-estimating, compensatory, transferring and reinforcing functions of emotions. The reinforcing function is phylogenetically the most ancient. It is connected with solution of the universal behavioural task of maximization-minimization of the appeared emotion, striving for "to" or "from". Replacing and transferring functions have been formed later, while reflecting-estimating one is the most young. It namely provides the wealth and diversity of emotions, based on complicated vital, social and cognitive needs. Such succession coincides with the evolution of the corresponding brain formations, with their phylogenetic age.

Affect↗

PubMed1997

[Proximal femoral fractures in patients over 75 years. Vital and functional prognosis of a cohort of 78 patients followed during 2.5 years].

PURPOSE OF THE STUDY: The purpose of this study was to highlight factors influencing vital and functional prognosis at 2.5 years of elderly people being treated for a proximal femoral fracture. MATERIAL: The study was based on 78 patients more than 75 years old admitted to the orthopedic department for emergency treatment. After post-operative care, patients were transferred to a geriatric readaptation unit. The average patient age at the time of surgery was 85 years. METHODS: This was a retrospective study. Survival graphs were established for the entire population as well as for the sub-populations characterized by a studied parameter. Mortality factors were compared via a univariable analysis. A multivariable logistical regression analysis isolated the factors explaining mortality at 12, 18, and 30 months and survival at 30 months, as well as factors explaining functional prognosis at 1 year. RESULTS: The overall mortality rate was 41 per cent, 48.5 per cent of deaths occur within the first year. Factors which are harmful for vital prognosis are the following: high degree of dependence before the fracture, the existence of a neuropsychiatric pathology, and age factor (more than 85 years). 61.5 per cent of surviving patients were independent for daily activities. 77 per cent of surviving patients lived in their usual place of residence. Factors which were harmful for functional prognosis were the following: type of the fall, symptomatic of an underlying pathological state, and existence of a neuropsychiatric pathology. Nutrition was also a predictive factor concerning the patient's out come. DISCUSSION: The average age of the studied population was higher than in most studies in literature. The treatment is mainly based on hip arthroplasty. The group of patients of over 85 have the highest mortality rate. However, a better survival rate at 18 months has been observed for patients older than 90 years. The delay before surgical care was significantly negative if longer than 6 days. However, a delay of 3 to 6 days was not significantly harmful for survival. Within the studied population, the maximum autonomy gain was observed during the first 6 months. The type of non-accidental fall, symptomatic of an associated pathology, was a factor for functional prognosis which has not been often mentioned. So was the biological deficit of nutrition. Social status acted as an indicator of functional status evolution. CONCLUSION: Therapeutic choices can only be guided by assessments of patients' vital and functional prognosis. A sophisticated or even expensive device should be demanded for patients with favorable prognosis. For patients with precarious functional and vital prognosis, priority should be given to less invasive techniques with immediate walking. The cost of the device should be correlated with patient's functional investment.

Age Factors↗

PubMed2006

The evolution of activity breaks in the nest cycle of annual eusocial bees: a model of delayed exponential growth.

BACKGROUND: Social insects show considerable variability not only in social organisation but also in the temporal pattern of nest cycles. In annual eusocial sweat bees, nest cycles typically consist of a sequence of distinct phases of activity (queen or workers collect food, construct, and provision brood cells) and inactivity (nest is closed). Since the flight season is limited to the time of the year with sufficiently high temperatures and resource availability, every break reduces the potential for foraging and, thus, the productivity of a colony. This apparent waste of time has not gained much attention. RESULTS: We present a model that explains the evolution of activity breaks by assuming differential mortality during active and inactive phases and a limited rate of development of larvae, both reasonable assumptions. The model predicts a systematic temporal structure of breaks at certain times in the season which increase the fitness of a colony. The predicted pattern of these breaks is in excellent accordance with field data on the nest cycle of the halictid Lasioglossum malachurum. CONCLUSION: Activity breaks are a counter-intuitive outcome of varying mortality rates that maximise the reproductive output of primitively eusocial nests.

Animals↗

PubMed1991

Behavioral inhibition in children: a possible precursor to panic disorder or social phobia.

A biological-environmental interaction currently provides the best explanation of an anxiety disorder's evolution. In this sense, anxiety disorders are like other medical disorders for which a person may have a predisposition. Our knowledge of the evolution of anxiety disorders would be enhanced by the ability to identify those persons predisposed to anxiety and to identify such "proneness" before an anxiety disorder emerges in adulthood. We discuss the developmental aspects of panic disorder and social phobia, in particular findings suggesting that behavioral inhibition in children may be a precursor to phobic disorders in adults. Only longitudinal studies will resolve whether childhood response patterns are specifically linked to the risk of developing anxiety disorders or other psychopathology across the life cycle. In the interim, we suggest some guidelines for parents and clinicians to meet the unique needs of the inhibited child.

Adult↗

PubMed1983

Birds, behavior, and anatomical evolution.

Study of more than 200 species suggests that the anatomical differences among birds are as big as those among other vertebrates of comparable taxonomic rank. The result is notable because, for more than 100 years, many biologists have believed that birds are more uniform anatomically than other classes of vertebrates. Furthermore, assessment of biochemical and geological evidence suggests that the time scale for bird evolution could be quite short. Hence, birds may share with placental mammals the distinction of having had a high rate of anatomical evolution, compared to that in lower vertebrates. The rate appears to have been very high in songbirds and higher primates and extremely high in the genus Homo. In an attempt to explain such contrasts in rates of anatomical evolution, we advance the hypothesis that in higher vertebrates, behavior, rather than environmental change, is the major driving force for evolution at the organismal level. This hypothesis predicts accelerated anatomical evolution in species composed of numerous mobile individuals with the dual capacity for behavioral innovation and social propagation of new habits. Consistent with this hypothesis, we demonstrate a correlation between relative brain size and rate of anatomical evolution in land vertebrates.

Animals↗

PubMed2006

Landscape bioacoustics allow detection of the effects of habitat patchiness on population structure.

Landscape structure may affect individual dispersal abilities, thus influencing the genotypic and phenotypic composition of populations. We analyzed the interplay among landscape, behavior, and evolutionary processes by correlating habitat patchiness to the variability in vocalizations of Dupont's Lark Chersophilus duponti, one of the most habitat-selective and rare European songbirds. We tape-recorded males throughout the species distribution in Spain, analyzed the spatial patterns of territorial call variation at different scales (individuals, populations, and broad geographic areas), and related acoustic variability to patterns of isolation by geographic distance and by landscape unsuitability (calculated by building a predictive model of habitat suitability). The differentiation of spectro-temporal call features resulted from both isolation by distance and isolation by landscape unsuitability mechanisms. Landscape connectivity was often a better determinant of call differentiation than simple straight-line distance between individuals, providing the first evidence that call transmission can be limited by the presence and distribution of patches of adequate habitat, which likely mediates bird dispersal. Landscape patchiness resulted in a reduction of acoustic diversity (repertoire size) within populations, and a parallel increase in differentiation among populations. Landscape bioacoustics can represent a promising tool for estimating population structure, although the study of animal communication cannot be viewed as an alternative, but a source of complementary information to genetics, given that it provides evidence of male-male transmission and social and cultural phenomena that are currently undetectable from molecular data.

Acoustics↗