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At least 541 records · Page 30Linked to original sources
PubMed2005

Patterns of male scent-marking in Propithecus edwardsi of Ranomafana National Park, Madagascar.

Scent-marking behavior has been well documented in many primate species. Three common functions attributed to scent-marking in males of multi-male/multi-female lemur species include: 1) advertisement of individual identity, 2) territorial defense, and 3) reproductive suppression. We examined the average number of scent-marks per hour exhibited daily by adult male sifakas (Propithecus edwardsi) and found that patterns of scent-marking changed with season, natal status, and dominance status. Males in single-male groups scent-marked at the highest rate, followed by dominant males, males of equal status, and subordinate males. Non-natal males generally scent-marked at higher rates than natal males, and adult males living in a natal group without a parent marked at higher rates than males living with a parent. All males scent-marked at higher rates in the migration season compared to the other seasons. These patterns were consistent with territorial defense and advertisement to females, and the suggestion that these chemical signals impart information concerning status. Since scent-marking behavior tracked seasons and varied with both dominance and natal status, it may serve multiple functions in males.

Animals↗
PubMed2006

Scent marking strategies of New World primates.

This paper reviews recent findings on scent-marking behavior in wild New World primates. These findings are used to examine three functional hypotheses: territoriality, regulation of social and reproductive dominance, and mating competition/mate attraction. Available data provide little evidence for a territorial function of scent-marking behavior in New World primates. Evidence for a function in the regulation of social and reproductive dominance is ambiguous. The patterns of scent marking found so far (i.e., rates of scent marking according to sex and social or reproductive status, and the spatial distribution of scent marks), and the sparse information on responses to scent marks are consistent with a hypothesized function in intrasexual competition and intersexual mate choice. Suggestions for future research are made.

Animal Communication↗
PubMed2001

The effects of diseases on competing species.

In this paper we study the dynamics of two competing species when one of them is subject to a disease. In order to keep the model simple, we present it under the strong assumption that the disease cannot cross the species barrier. We answer several important questions about the long term behavior of the environment. In this situation, no population is necessarily wiped out. Also, not every individual of the infected species is bound to contract the disease. Finally, disease-induced persistent cycles for the populations are admissible.

Animals↗
PubMed1997

Locomotor ecology of Lepilemur edwardsi and Avahi occidentalis.

A well-known principle holds that where food supply is limited, two sympatric species with the same diet, morphology, and behavior will compete, leading to exclusion of one species or differentiation of their ecological niches. Avahi occidentalis and Lepilemur edwardsi are two saltatory, nocturnal folivorous lemurs of similar body size which live sympatrically over much of their range and may often be seen feeding in the same trees. We report a study of their locomotor behavior, carried out in order to determine to what extent locomotion might contribute to niche separation. Avahi lives at a higher level in the forest and is the more committed leaper, with a much larger home range and nightly travel distance, while Lepilemur climbs more and has a very small nightly travel distance. Avahi uses small, low-angled supports more often, while Lepilemur makes more use of large, high-angled supports (however, neither species uses vertical supports at a frequency greater than the availability of such supports in the forest stratum in which they live). Both species tend to land on larger-diameter supports on longer leaps, but Avahi also takes off from larger-diameter supports in longer leaps, reducing loss of energy to the substrate during takeoff. We suggest that the differences in locomotion and ranging behavior between them are consistent with niche differentiation on the basis of food quality, Avahi investing more energy in harvesting better quality but more patchy food, Lepilemur minimizing expenditure in harvesting a less selective, quantitatively poorer diet.

Animals↗
PubMedDate not supplied

[The modification of the intraspecific behavior of male rats raised in isolation with different variants of interaction with related animals].

It was found that intraspecific behaviour of male rats having been transformed in consequence of breeding under the conditions of social isolation could be modified afterwards by an experience of social contacts. Long-term keeping the isolatedly bred rats with their mates in adulthood decreases the level of intraspecific sociability but does not affect the relatively high level of aggression of the animals under study. On the contrary, the short-term periodic social contacts with the mates in a situation of competition for water decrease only the level of aggression but not that of intraspecific sociability. However, in any case the transformations of the species-typical ritual of aggressive behaviour in consequence of early isolation are steady and are not corrected by later social contacts.

Aggression↗
PubMed2001

Solvation effect on organic compound interactions in soil organic matter.

We examine sorption of pyridine by soil organic matter (SOM) from different organic media including n-hexadecane, acetonitrile, acetone, and n-hexadecane mixtures with either acetonitrile or acetone and compare it with sorption from water. By using an activity-based comparison, we distinguish between solvent-assisted and solvent-competitive sorption behavior. Pyridine was selected because it forms strong complexes with phenolic and carboxylic groups, such that site interactions should dominate interactions in SOM. It is anticipated that pyridine sorption will be illustrative of the importance of disrupting strong interactions in a condensed, shrunken SOM phase for many organic compounds. It was generally found that activity-normalized pyridine uptake was assisted by polar solvent molecules rather than suppressed due to competition. An explanation is tendered on the basis of our earlier hypothesis of water-assisted disruption of polar SOM contacts. Certain polar moieties of dry SOM are unavailable for compound sorption due to strong interactions between them. By penetrating SOM structure, solvent molecules (and water) solvate (hydrate) polar moieties creating new sorption sites. Solvent molecules must solvate both moieties of the polar contact, such that the driving force for solvent-assisted sorption is solvation of the partner of the disrupted contact that does not directly interact with the sorbate.

Adsorption↗
PubMed2001

Dynamical mechanism for coexistence of dispersing species.

Dispersal of organisms may play an essential role in the coexistence of species. Recent studies of the evolution of dispersal in temporally varying environments suggest that clones differing in dispersal rates can coexist indefinitely. In this work, we explore the mechanism permitting such coexistence for a model of dispersal in a patchy environment, where temporal heterogeneity arises from endogenous chaotic dynamics. We show that coexistence arises from an extreme type of intermittent behavior, namely the phenomenon known as on-off intermittency. In effect, coexistence arises because of an alternation between synchronized and de-synchronized dynamical behaviors. Our analysis of the dynamical mechanism for on-off intermittency lends strong credence to the proposition that chaotic synchronism may be a general feature of species coexistence, where competing species differ only in dispersal rate.

Animals↗
PubMedDate not supplied

Integrated delivery systems. Evolving oligopolies.

The proliferation of Integrated Delivery Systems (IDSs) in regional health care markets has resulted in the movement of these markets from a monopolistic competitive model of behavior to an oligopoly. An oligopoly is synonymous with competition among the few, as a small number of firms supply a dominant share of an industry's total output. The basic characteristics of a market with competition among the few are: (1) A mutual interdependence among the actions and behaviors of competing firms; (2) competition tends to rely on the differentiation of products; (3) significant barriers to entering the market exist; (4) the demand curve for services may be kinked; and (5) firms can benefit from economies of scale. An understanding of these characteristics is essential to the survival of IDSs as regional managed care markets mature.

Costs and Cost Analysis↗
PubMed2004

Method matters: effects of explicit versus implicit social comparisons on activation, behavior, and self-views.

The authors investigated the impact of explicit versus implicit social comparisons. Simply being primed with a superior or inferior standard (implicit comparison) produced contrast as evidenced by accessibility of self-knowledge (Study 2), intellectual performance (Study 3), and self-ratings (Study 4), inconsistent with the standard. However, when participants were explicitly asked to compare, increased accessibility of a similarity focus (Study 1) and self-knowledge, behavioral performance, and self-ratings congruent with the standard were obtained more easily, indicative of assimilation. Explicit comparisons produced assimilation when the self was seen as mutable (rather than immutable; Study 4), when behavioral consequences were measured immediately after the comparison (rather than later; Study 3), and when the participants described (rather than ranked) their intelligence (Study 5). These findings support the interpretation comparison model. Implications for resolution of empirical inconsistencies in the social comparison literature are discussed.

Adult↗
PubMed2006

Perceiving intergroup conflict: from game models to mental templates.

This article puts forward a parsimonious framework for studying subjective perceptions of real-life intergroup conflicts. Four studies were conducted to explore how individuals perceive the strategic properties of the Israeli-Palestinian conflict. Studies 1 and 2 found theory-driven associations between people's subjective perception of the conflict's structure as a Chicken, Assurance, or Prisoner's Dilemma game and their ingroup/outgroup perceptions, national identification, religiosity, political partisanship, voting behavior, and right-wing authoritarianism. Studies 3 and 4 manipulated the saliency of the needs for cognitive closure and security, respectively, demonstrating that these needs affect people's endorsement of the game models as descriptions of the conflict.

Adolescent↗
PubMed1997

Effects of competitive and non-competitive NMDA receptor antagonists on behavioral responses induced by 7-OH-DPAT and quinpirole in rats.

The administration of dizocilpine (0.06 mg kg-1), but not of CGP 43487 (0.75 mg kg-1), counteracted the hypolocomotion induced in the rat by low doses (5-80 microg kg-1) of the putative D3 dopamine agonist 7-OH-DPAT. Both NMDA antagonists did not change the reduced locomotion due to the administration of low doses (12.5-50 microg kg-1) of the D2 agonist quinpirole. In spite of the lack of effect of either NMDA receptor antagonist on D2 or D3 recognition sites, as shown by our radioligand binding studies, the behavioural findings suggest that the non-competitive, but not the competitive, NMDA receptor antagonist physiologically antagonizes dopamine D3 receptor mediated mechanisms. Both NMDA receptor antagonists failed to modify the hyperlocomotion induced by high doses (160 and 320 microg kg-1) of 7-OH-DPAT, whereas they inhibited the same behavioural response produced by high doses of quinpirole (150 and 300 microg kg-1). The different effect of the NMDA receptor antagonists on the behavioural responses induced by the dopaminergic agonists could be explained by the different activity of 7-OH-DPAT and quinpirole on D3/D2 receptors. Either dizocilpine or CGP 43487 induced stereotyped responses to high doses of 7-OH-DPAT. This suggests that both NMDA receptor antagonists could potentiate dopaminergic function in the striatum, a region critically involved in the generation of stereotyped behaviour.

2-Amino-5-phosphonovalerate↗
PubMed1993

Effect of polyurethane surface chemistry on its lipid sorption behavior.

The relationships among surface, bulk properties and lipid sorption behaviors of segmented polyurethanes (SPUs) with various polyol soft segments were investigated. The polyols used in this study were poly(ethylene oxide) (PEO), poly(tetramethylene oxide) (PTMO), and poly(dimethylsiloxane) (PDMS). The hard segment of these segmented polyurethanes was composed of 4,4'-diphenylmethane diisocyanate and 1,4-butanediol, present at 50 wt%. X-ray photoelectron spectroscopic (XPS) and dynamic contact angle measurements were carried out in order to analyze the surface chemical structure in the air- and water-equilibrated states. XPS revealed that in the air-equilibrated state, lower surface free energy components were enriched at the air-solid interface, whereas in the water-equilibrated state, higher surface free energy components were enriched at the water-solid interface. The change in environment from air to water induced the surface reorganization in order to minimize interfacial free energy. Lipid sorption behaviors of SPUs were investigated by means of infrared spectroscopy. Even after extensive rinsing of the surface, the amount of lipid present on the SPU surface was more than that calculated on the assumption that a monolayer covers the SPU surface. Therefore, the lipid was not only adsorbed on the surface of SPU but absorbed into SPU. The SPU with hydrophilic PEO sorbed larger amount of phospholipid compared with that with hydrophobic polyol such as PTMO and PDMS. Also, the competitive sorption behaviors of phospholipid and cholesterol from their mixed liposome solution were studied. The ratio of sorbed cholesterol to phospholipid increased with an increase in surface hydrophobicity owing to the hydrophobic nature of cholesterol.

Absorption↗
PubMed2006

A tale of two diversifications: reciprocal habitat shifts to fill ecological space along the pond permanence gradient.

The Enallagma and Lestes damselflies have both diversified and adapted over the past 10-15 million years to the various ecological milieus found along the pond permanence gradient among North American ponds and lakes. Previous articles have explored this diversification process for Enallagma. In this article, we present a phylogenetic hypothesis for the North American Lestes, use this hypothesis to reconstruct Lestes diversification, and compare the diversification processes inferred for Lestes and Enallagma. The results of this study suggest that Lestes began in temporary ponds where large dragonflies are the top predators, while Enallagma began in permanent lakes where fish are the top predators. Starting from these different ancestral habitats, both genera have invaded and adapted to habitats already occupied by the other genus. Moreover, these adaptive habitat shifts involved substantial convergence on the behaviors used to deal with fish and dragonfly predation in both genera and a major life-history shift from diapausing to directly developing eggs in Lestes. However, in Lestes lineages invading fish lakes, swimming speed and morphology did not change to match those of Enallagma species, illustrating that reciprocal shifts between alternative selection regimes are not necessarily evolutionary opposites. Also, the greater sizes and growth rates of Lestes species compared to Enallagma species, which should impart substantial ecological advantages in competition between the genera, were shown to result from phylogenetic inheritance and not from adaptive diversification. This historical analysis of diversification raises new questions about the relationship between the macroevolutionary mechanisms driving lineage diversification and the ecological mechanisms structuring local food webs and regional species assemblages.

Adaptation, Physiological↗
PubMed1979

Feeding behaviour and diet of chimpanzees (Pan troglodytes troglodytes) in the Okorobikó Mountains of Rio Muni (West Africa).

Some aspects of the nutritional behaviour of the Okorobikó-Matama (Rio Muni, West Africa) chimpanzees have been studied over two periods--from June 1963 to September 1964 and from July 1966 to February 1969. This research totaled 640 h, 119 of which were in sustained contact with the animals. We have complied a list of 43 plant and two termite species consumed by the chimpanzees. We studied the relative importance of the plants consumed in terms of the four principal biotopes and seasonal cycles, the feeding behavior, the rhythm of activity and chimpanzees' vertical stratification during feeding. We also took into accout group dynamics as a function of feeding, communication and polyspecific associations with other primates. We finally compared some aspects of the nutrition of these chimpanzees with that of gorillas living in nearby zones.

Africa, Western↗
PubMed1980

Women's attitudes toward other women--myths and their consequences.

Notions that women generally hold negative views of other women and demonstrate their poor opinions behaviorally by not assisting or promoting the careers of other women are specious. Where nonassistance can be located as a pattern at all, it is generally due to women's relative lack of power in the structure of which they are a part, or due to personality differences which are not gender specific.

Attitude↗
PubMed2006

Leadership run amok. The destructive potential of overachievers.

The desire to achieve is a major source of strength in business, and it is on the rise. The authors' consulting firm has seen a steady increase in the extent to which achievement motivates managers. There's a dark side to the trend, however. By relentlessly focusing on tasks and goals, an executive or company can damage performance. Overachievers tend to command and coerce, stifling subordinates. Psychologist David McClelland identified three drivers of behavior: achievement, meeting a standard of excellence; affiliation, maintaining close relationships; and power, having an impact on others. He said the power motive comes in two forms: personalized, in which the leader draws strength from controlling people, and socialized, where the leader derives strength from empowering people. Studies show that great charismatic leaders are highly motivated by socialized power. To look at how motives and leadership style affect a group's work climate and performance, the authors studied 21 senior managers at IBM. The leaders who created high-performing and energizing climates got more lasting results by using a broad range of styles, choosing different ones for different circumstances. Rather than order people around, they provided vision, sought buy-in and commitment, and coached. If you're an overachiever seeking to broaden your range, you can study your actions and ask your team, peers, and manager to give you honest feedback. You can adopt specific new behaviors, such as engaging your team in a discussion of how to achieve goals, rather than issuing a set of directives. The company as a whole can play a part, too: Organizations must learn when to draw on the achievement drive and when to rein it in.

Administrative Personnel↗
PubMed1978

Approach-withdrawal response competition (AW-RC), displacement, and behavior modification.

This paper reviews displacement theory and animal research as derived from approach-withdrawal response competition (AW-RC), with a selected emphasis on clinical implications. AW-RC displacement is seen as part of the larger area of behavior modification while nevertheless distinguished from the larger area by a singular model and methodology. It is suggested that a lack of operational analysis of AW-RC displacement and behavior modification is responsible for some confusion about the two areas, has retarded developments and conclusions about behavior modification, and has contributed to, or produced, termination of research on AW-RC displacement. This review uncovers two major sets of results and one interesting observation. First, the displacement effect and the extinction effect of displacement are strongly supported, but the therapeutic effect of displacement is not supported. Second, time-delay that is characterized by eating under deprivation in an irrelevant situation does appear to produce true therapeutic effects of large magnitude. Berkun's observation, opening to other nondisplacement but AW-RC related observations and findings, suggests separable aspects of AW-RC behavior that are not correspondingly observable with other methodologies.

Animals↗