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At least 19 recordsLinked to original sources
PubMed1978

Problem of behavioral plasticity in slave-making Amazon-ant Polyergus rufescens Latr. and in its slave-ants Formica fusca L. and Formica cinerea Mayr.

Changes in the natural behavior, expressing adaptation to cohabitation in a community, were observed in the slave-making ants P. rufescens and the slave-species F. fusca and F. cinerea. After a few raids, the initially undirected arousal evoked in the slaves by the amazons' raids, begins to acquire attributes appropriate to the situation, but completely different in both studied slave-species. F. cinerea picks up the pupae abandoned on the nest by the slave-making ants and eventually begins to wrench them away from the amazons arriving with prey. F. fusca, whose nests have openings so narrow that it prevents the mass entry of amazons with prey, begin to enlarge those openings shortly after the amazons return. After a certain number of raids, F. fusca begin to enlarge the openings immediately after the departure of the amazons for the slave-raid. The amazons, on their side, adjust soon to the specific behavior of the given slave-species; in nests with F. fusca, they make use of enlarged openings, carrying their prey through them into the nest; when F. cinerea are the slaves, most of the amazons begin to drop the pupae on the nest, and later even surrender the prey to the slaves who meet them. It is supposed that in all three species, under the influence of specific conditions there occurs the process of learning of new forms of behavior.

Animals↗
PubMed2004

Regulation of cuticular and postpharyngeal hydrocarbons in the slave-making ant Polyergus rufescens: effect of Formica rufibarbis slaves.

The purpose of this study was to compare cuticular hydrocarbon profiles of slave-making Polyergus rufescens ants reared alone or with their Formica rufibarbis slaves. Chemical analyses showed that due to the close contacts occurring when the Formica were tending the Polyergus, the synthesis of the cuticular hydrocarbons carried by the slaves was enhanced in the slave-makers. The postpharyngeal hydrocarbon levels increased during the first 15 days of life, whether or not the Polyergus were exposed to Formica. Our findings suggest that Polyergus is able to secrete all components of their cuticular hydrocarbon blend and that none are acquired through contact with Formica. In addition to presenting our experimental evidence, several hypotheses are proposed to explain the synthesis and regulation of hydrocarbon blends borne when these two species cohabitate within a single colony.

Age Factors↗
PubMed1987

The age-sex structure of the slave population in Harris County, Texas: 1850 and 1860.

The effect of the slave system on demography can be revealed by examining the age-sex structure of slave populations. The age-sex structure of slaves in Harris County, Texas is investigated using the 1850 and 1860 slave schedules. Median ages for black and mulatto slaves suggest that the population was young. Population pyramids exhibit a narrow base and top with a broad middle. The high proportion of slaves between 10 and 30 years of age and the increase in population size between 1850 and 1860 were mainly related to the importation of slaves and only partly due to natural increase. The data also show that black slaves were older on small plantations while mulattoes were older on larger farms. It is suggested that differential treatment in terms of purchase practices, assignment of tasks, food allocation, and/or differential susceptibility to infectious diseases may account for this pattern.

Black or African American↗
PubMed1992

A coupled pacemaker-slave model for the insect photoperiodic clock: interpretation of ovarian diapause data in Drosophila melanogaster.

A coupled circadian oscillator model for the insect photoperiodic clock is described which consists of a hierarchically arranged pacemaker and slave. The pacemaker is self-sustained, temperature compensated, and entrainable by the light cycle; the slave is a damping oscillation receiving entrainment from two sources, from the pacemaker via a coupling factor, and also directly from the light. The damping slave oscillation is seen as the "photoperiodic oscillator", equivalent to that proposed earlier by Lewis and Saunders (1987). The present simulations describe the effect of the strength of the coupling factor between hypothetical short- and long-period pacemaker oscillations (modelled on the "clock" mutants perS and perL2 in Drosophila melanogaster) and a slave oscillation with a period of about 24 hours. The output is presented in terms of photoperiodic response curves and Nanda-Hamner, or resonance, plots. With a high coupling strength, the pacemakers strongly entrain the slave, but with a low coupling strength the slave's properties are more evident. The model is presented as a possible explanation for recent ovarian diapause data in D. melanogaster "clock" mutants (Saunders 1990), but also as a more general model for the role of the insect circadian system in seasonal time measurement.

Animals↗
PubMed2003

Coevolution between slave-making ants and their hosts: host specificity and geographical variation.

We explored the impact of a slave-making ant, Protomognathus americanus, on two of its hosts, Leptothorax longispinosus and L. ambiguus. We showed that, on average, slave-maker colonies conduct raids on 2.7 L. longispinosus and 1.4 L. ambiguus nests in a single year. The more common host, L. longispinosus, survives raiding and colony-founding events in a third of the cases, but the less common host rarely survives attacks from the slave-makers. We compare our results, collected in Vermont, to a study conducted in New York where the slave-maker pressure is much stronger. Our results suggest that in Vermont the slave-maker has a sparing strategy when raiding L. longispinosus, but not when raiding L. ambiguus. Thus coevolution between slave-making ants and their hosts shows host specificity and geographical variation.

Aggression↗
PubMed1994

Bilateral control of master-slave manipulators for ideal kinesthetic coupling--formulation and experiment.

In this paper, the analysis and design of master-slave teleoperation systems are discussed. The goal of this paper is to build a superior master-slave system that can provide good maneuverability. We first analyze a one degree-of-freedom system including operator and object dynamics. Second, some ideal responses of master-slave systems are defined and a quantitative index of maneuverability is given, based on the concept of ideal responses. Third, we propose new control schemes of master-slave manipulators that provide the ideal kinesthetic coupling such that the operator can maneuver the system as though he/she were directly manipulating the remote object himself/herself. The proposed control scheme requires accurate dynamic models of the master and slave arms, but neither parameters of the remote object nor the operator dynamics is necessary. Last, the proposed control scheme is introduced to a prototype master-slave system and the experimental results show the validity of the proposed scheme.

Engineering↗
PubMed2001

Facultative and obligate slave making in Formica ants.

Here we show for the first time that the presumed facultative slave-making ant Formica subintegra does not activate outside its nest until July and August, when it raids slaves. A comparative behavioral study of seasonal and daily activities, retrieval of prey, and nest maintenance of F. subintegra, the obligate slavemaker Polyergus breviceps, and the facultative Formica subnuda, shows that the behavioral repertory of F. subintegra closely resembles that of P. breviceps and clearly differs from the repertory of F. subnuda. Unlike P. breviceps, F. subintegra has retained some nest-building activity which, owing to lack of competence, does not contribute to nest maintenance. We suggested earlier that F. subintegra is probably an obligate slavemaker, because it always has in its colonies a large proportion of slaves of the total workforce, whereas F. subnuda fares well even without slaves. This, coupled with no foraging in early summer and a raiding period later on, strongly suggests that F. subintegra is an obligate slave-making ant.

Animals↗
PubMed1996

Discovering the invisible Puerto Rican slave family: demographic evidence from the eighteenth century.

Traditional notions that family life among slaves during the pre-plantation period in the non-Hispanic Caribbean was necessarily unstable are fading in light of new research. Although marriage among this segment of the population in Caguas, Cayey, San Germán, and Yauco--rural parishes in Puerto Rico--involved only a fraction of the overall number of marriages in these communities, the marriage of slaves was much more frequent than previously assumed. Family life among the eighteenth-century Puerto Rican slave population appears to have been quite stable, as shown by the reconstruction of birth intervals for both married and unmarried mothers. Married and unmarried mothers exhibited similar reproductive behavior. These results strongly suggest that a majority of the unmarried slave mothers lived in unions that were not institutionally recognized, but that were nevertheless stable, as indicated by the high percentage of their children born at intervals comparable to those of married mothers. If unmarried mothers were living in stable consensual unions, then our understanding of these slave family units during the colonial period must be reassessed not only for Puerto Rico but possibly for the rest of the Caribbean and Latin America.

Black or African American↗
PubMed1997

Baseline studies in the Slave River, NWT, 1990-1994: Part II. Body burden contaminants in whole fish tissue and livers.

The Northwest Territories section of the Slave River is the recipient of chemical compounds from a variety of sources, including upstream industry and agriculture. In 1990, concerned government agencies formulated a practical, focussed, and comprehensive environmental monitoring program to assess contamination in the river and the Slave River Environmental Quality Monitoring Program was established. The program was designed to respond to the distinct requirements of two major monitoring goals. The first priority was to ascertain whether the fish in the Slave River were safe to eat. The second goal was to establish a baseline data set with which to compare future effects from upstream activities and long-range transport of contaminants. From the data gathered in the present study, it appears that whole tissue of fish (muscle) is fit for human consumption. Throughout the monitoring period, consistently low concentrations of organochlorine pesticides, PCBs, dioxin and furan isomers, PAHs, chlorinated phenolics, and heavy metals have been observed and median concentrations have all been below federal fish consumption advisories. Also, the numerous data values below analytical detection limits attest to the relatively uncontaminated nature of the fish. These results were comparable with other studies conducted on arctic animals. The heavy metals observed in fish tissue are probably of natural origins, since inorganic analyses of suspended sediment in the Slave River indicated relatively elevated levels, with no known anthropogenic source. While the present study concluded that contaminant levels in whole fish are low, toxaphene levels in burbot livers should continue to be monitored since concentrations were consistently above fish consumption advisories during the monitoring and are eaten extensively by the native peoples. The second goal of the monitoring program was to develop a baseline data set and the values tabled in the current paper are useful in establishing a foundation for future comparison.

Animals↗
PubMed2002

Caring as a slave morality: Nietzschean themes in nursing ethics.

BACKGROUND: Sceptical arguments about 'caring' can be divided into three categories. First, it is suggested that, while caring is no doubt an admirable thing in itself, it is just one ideal among others. Secondly, it is claimed that caring is not really a virtue at all, and that it should be regarded as more of a vice, because it promotes favouritism, injustice, and self-deception. Thirdly, there is a worry that caring is not politically realistic, and that its advocates underestimate the powerful organizational and social structures which conspire to subvert nursing. AIM: This paper outlines a fourth, and more radical, type of scepticism, which explains why caring is subject to these drawbacks. In doing so, it considers the relation between caring, phenomenology and holism in nursing discourse, and the way in which all three fit together to form the 'caring paradigm'. METHODS: The paper adopts a genealogical approach, borrowed directly from Nietzsche's Genealogy of Morality. That book argues that the values associated with caring are the expression of a profound resentment, harboured by the slaves (weak, powerless, timorous) against the nobles (strong, powerful, self-confident). Caring represents an inversion, a sort of 'fantasy revenge', in which the nobles can be portrayed as 'evil', while the slaves portray their own weakness as 'good'. Taking its cue from Nietzsche, the paper shows that the Genealogy narrative can be transposed into a modern health care context, with nurses as the 'slaves' and the medical profession as the 'nobles'. CONCLUSIONS: The ideology of caring is, in the Genealogy's terms, a slave morality. It represents an attack on the 'medical-scientific model', motivated by resentment, and designed to establish nursing's superiority. Its effects have been debilitating, and it has prevented nursing from becoming a 'noble' (that is, a properly scientific) discipline.

Christianity↗
PubMed2000

'Slave' metabolites and enzymes. A rapid way of delineating metabolic control.

Although control of fluxes and concentrations tends to be distributed rather than confined to a single rate-limiting enzyme, the extent of control can differ widely between enzymes in a metabolic network. In some cases, there are enzymes that lack control completely. This paper identifies one surprising origin of such lack of control: If, in a metabolic system, there is a metabolite that affects the catalytic rate of only one enzyme, the corresponding enzyme cannot control any metabolic variable other than the concentration of that metabolite. We call such enzymes 'slave enzymes', and the corresponding metabolites 'slave metabolites'. Implications of the existence of slave enzymes for the control properties of enzymes further down the metabolic pathway are discussed and examined for the glycolytic pathway of yeast. Inadvertent assumptions in metabolic models may cause the latter incorrectly to calculate absence of metabolic control. The phenomenon of slave enzymes may well be important in enhancing metabolic signal transduction.

Catalysis↗
PubMed2002

Slaving: solvent fluctuations dominate protein dynamics and functions.

Protein motions are essential for function. Comparing protein processes with the dielectric fluctuations of the surrounding solvent shows that they fall into two classes: nonslaved and slaved. Nonslaved processes are independent of the solvent motions; their rates are determined by the protein conformation and vibrational dynamics. Slaved processes are tightly coupled to the solvent; their rates have approximately the same temperature dependence as the rate of the solvent fluctuations, but they are smaller. Because the temperature dependence is determined by the activation enthalpy, we propose that the solvent is responsible for the activation enthalpy, whereas the protein and the hydration shell control the activation entropy through the energy landscape. Bond formation is the prototype of nonslaved processes; opening and closing of channels are quintessential slaved motions. The prevalence of slaved motions highlights the importance of the environment in cells and membranes for the function of proteins.

Energy Transfer↗
PubMed2001

Colony structure of a slavemaking ant. II. Frequency of slave raids and impact on the host population.

The parasite pressure exerted by the slavemaker ant Protomognathus americanus on its host species Leptothorax longispinosus was analyzed demographically and genetically. The origin of slaves found in colonies of the obligate slavemaker was examined with nuclear and mitochondrial DNA markers to make inferences about the frequency and severity of slave raids. Relatedness of enslaved L. longispinosus workers in the same nest was very low, and our data suggest that, on average, each slavemaker nest raids six host colonies per season. Therefore, the influence of slavemaker species on their hosts is much stronger than simple numerical ratios suggest. We also found that slave relatedness was higher in small than in large slavemaker nests; thus, larger nests wield a much stronger influence on the host. We estimated that in the study population, on average, a host nest has a 50% chance of being attacked by a slavemaker colony per year. Free-living Leptothorax colonies in the vicinity of slavemaker nests did not represent the source of slaves working in P. americanus colonies, which suggests that raided nests either do not survive or migrate after being raided. Colony composition and intranest relatedness of free-living L. longispinosus colonies differed markedly between areas with slavemakers and those that are parasite-free. In the presence of slavemakers, host colonies were less likely to be polygynous and had fewer workers and a higher relatedness among worker brood. Host nests with slavemaker neighbors allocated more resources into sexuals, possibly caused by these shifts in nest demography. Finally, enslaved Leptothorax workers in P. americanus nests appeared to be less efficient than their counterparts in free-living colonies. Thus, slavemakers exert a much stronger impact on their hosts than had previously been suspected and represent an unique system to study parasite-host coevolution.

Animals↗