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1.
In U.S. nursing homes, it is the job of nursing assistants to tend to residents' basic bodily needs, including elimination and incontinence care. Given their frequent contact with pollutants, aides are very much at risk of becoming "polluted people." In this article, I investigate how nursing assistants' continual contact with contaminating substances impacts their status within the workplace, their relationships with others, and their attitudes toward their work and themselves as workers. I also explore how aides manage their encounters with pollutants and their stigmatized role as "dirty workers." In doing so, I hope to explicate the meaning of elimination and of incontinence caregiving in the United States.  相似文献   

2.
Colonies of the fire ant, Solenopsis invicta, can survive flood conditions by forming a raft of ants that floats on the water’s surface until the flood recedes or higher ground is found. Having been forced from the protection of their subterranean nests, rafting colonies are totally exposed and are without retreat. I tested the hypothesis that rafting S. invicta colonies would compensate for their elevated vulnerability by increasing their defensiveness. I measured defensiveness using the amount of venom workers delivered per sting (venom dose), since the repellent effects (i.e., pain and tissue damage) of fire-ant venom are dose-dependent. In the laboratory I assayed colony defensiveness before and after flooding colonies from their nests with water. Colonies were consistently and significantly more defensive while rafting (i.e., each colony’s workers delivered higher venom doses when their colony was rafting than they did when it was assayed pre-flood). The larger venom doses of rafting colonies may reduce their chances of being damaged by encounters with other animals by reducing the duration of such encounters through increased repellency. Encounters with S. invicta during flood conditions have the potential to be unusually dangerous; large concentrations of workers are exposed and available for defense, and they deliver significantly larger venom doses when they sting. Received 29 March 2005; revised 20 June 2005; accepted 24 June 2005.  相似文献   

3.
Insect societies are characterized by a relatively sophisticated division of labor; they form tightly knit groups that must effectively exclude non‐members from the colony. However, the Neotropical predatory ant Ectatomma tuberculatum can harbor several specific myrmecophiles and, in particular, various eucharitid parasitoid wasp species. Adult wasps eclose in the host nests and are removed by worker ants without harm. Previous observations suggest that only a few workers perform this task. To test this hypothesis, we introduced different types of intruders, live and dead, pentane‐washed broad‐nosed grain weevil individuals (Caulophilus oryzae) and dead, pentane‐washed eucharitids (Dilocantha lachaudii), into laboratory colonies containing individually marked workers. We recorded all encounters and behaviors until the intruders were removed. Certain workers removed intruders more frequently than expected by chance. The number of encounters with an intruder was positively correlated with the number of removals performed by the workers. For each nest, a small group of workers was identified as specialized in intruder removal. A subset of very committed workers in the specialists group that performed up to 57% of removals qualified as hyperspecialists or elite workers. The behavioral sequences differed based on the type and condition of the intruder: the sequence was more complex and included numerous aggressive behaviors (mandibular strikes and attempts at stinging) when workers encountered a live weevil. In contrast, the behavioral sequences with dead, pentane‐washed insects were characterized by numerous detections through contact that did not lead to rejection and by the intruders simply being seized and removed from the nest. Overall, the data show that the ants discriminated between live and pentane‐washed intruders and adjusted their behavior accordingly. This is the first demonstration in ants of both behavioral specialization and hyperspecialization in intruder removal.  相似文献   

4.
This paper examines the behaviors used by male gorillas (G. gorilla beringei) to influence female choice during inter-group encounters. Encounters are related to the acquisition of females rather than to the defense of a group's range. Data on 58 independent encounters confirms that encounters are generally aggressive, but that contact aggression is less frequent than previously reported. A high number of potential migrants in one of the groups involved, rather than the newness of either group, predicts the likelihood of contact aggression between males. Encounters with a newly formed unit last longer than encounters involving established groups. Male herding serves to prevent female transfer. Females without dependent offspring are more likely than others to be herded. Proceptive females are the target of herding more often than non-proceptive cycling females. Groups where herding has been observed are more likely to be newly formed, and they include significantly more males. This last result confirms that there are advantages to male cooperation in gorillas. It also raises the question of why such cooperation does not occur more often. © 1993 Wiley-Liss, Inc.  相似文献   

5.
Drawing on ethnographic research on Vietnamese migrant workers in Taiwan, I seek to engage with and contribute to the scholarship on migrant networks and social capital. My research demonstrates that migrant networks are central to the social life of Vietnamese workers, offering not only a vital source of material and psychological support but also a platform where relationships are developed, sustained and contested. It reveals both productive and destructive potentials of social capital in situations where the migrant labourer becomes a disenfranchized underclass and their radius of trust is unsettled by physical displacement. Through this research I highlight the complexities and subjectivities in individual experiences of social capital and offer important insights into the various ways in which social networks are reinterpreted and reconfigured at the intersection of mobility, class and ethnicity within the context of Asia.  相似文献   

6.
Has Predation Shaped the Social Systems of Arboreal Primates?   总被引:2,自引:0,他引:2  
I studied antipredator behavior in two species of monkeys to elucidate the role of predation in shaping the social systems of arboreal primates. I compared the responses of monkeys to auditory and visual contact with predators to response elicited by sound playback experiments using the recorded calls of predators. Changes in vigilance and aggregation persisting up to 30 min after predator encounter occurred in both cases. Measures of vigilance shed light on individual perceptions of risk, while aggregation measures—intragroup spatial cohesion and polyspecific associations—permit direct inference about the protective benefits of grouping for the monkeys. They responded to real predator encounters and simulations in similar ways. Thus, sound playbacks of predator vocalizations are effective to simulate predator proximity. Contrary to predictions, predator encounters did not lead invariably to increased cohesion within groups or to increased time spent vigilant. Moreover, behavior in polyspecific associations was no different from that in single-species groups. Only red colobus encountering chimpanzees behaved as predicted by increasing vigilance and intragroup cohesion. The red colobus social system may have developed to protect against chimpanzee attack. In contrast, red-tailed monkey encounters with raptors and chimpanzees involved no change in time spent vigilant, coupled with decreases in intragroup cohesion. I conclude that predation is not a uniform selective pressure and patterns of social behavior within groups do not predict antipredator behavior.  相似文献   

7.
While the racial and ethnic stereotyping practised by the employers of migrant domestic workers has received significant scholarly attention, these workers' racial essentializations of their employers have been largely ignored. Drawing upon interviews with Filipino migrant domestic workers in Singapore and Hong Kong, I present findings concerning the racial stereotypes these workers hold about white and Chinese employers. This stereotyping involves both racial distancing from local Chinese employers and racial alignment with expatriate white employers. This two-track racial project is a defensive tactic that allows Filipino workers to redefine themselves as occupying a higher position in the global racial order (as they see it) on cultural grounds. However, it also makes them complicit in naturalizing legacy stereotypes that valorize whites as morally and culturally superior. In addition, it encourages them to privilege the West as an idealized destination where they fantasize they will enjoy comfortable working conditions from local white employers.  相似文献   

8.
Ants use cuticular hydrocarbons (CHC-profiles) as multicomponent recognition cues to identify colony members (nestmates). Recognition cues (label) are thought to be perceived during ant–ant encounters and compared to a neuronal template that represents the colony label. Over time, the CHC-profile may change, and the template is adjusted accordingly. A phenotype mismatch between label and template, as happens with CHC-profiles of foreign workers (non-nestmates), frequently leads to aggressive behavior. We investigated the template reformation in workers of the carpenter ant Camponotus floridanus by masking their antennae with postpharyngeal gland (PPG) extracts from nestmates or non-nestmates. The behavioral response of manipulated workers encountering unmanipulated workers was measured independently after 2 and after 15 h. After 2 h of incubation, workers treated with either of the two PPG-extracts showed low aggression towards nestmates and high aggression towards non-nestmates. In contrast, after 15 h of incubation, workers treated with non-nestmate PPG-extract showed low aggression towards both nestmates and non-nestmates. The slow (>2 h) adjustment of the template indicates a reformation localized in the central nervous system rather than in chemosensory neurons. In addition, our data show that template adjustment to a new CHC-profile does not impair the assessment of the old CHC-profile as nestmate label.  相似文献   

9.
Rupert Stasch 《Ethnos》2015,80(4):433-447
ABSTRACT

A growing body of ethnographic work examines tourism in which visited people are figured as embodying an archaic human condition outside modernity. I suggest that this work's core subject is the structure of articulations between people who understand their close involvement very differently. I then highlight two more specific themes that cut across this issue's case studies from Kenya, Indonesia, China, and Papua New Guinea. One is that ethnographers trace participants' disparate understandings of specific interactional media, since these contact points and their plural make-up are the actual substance of articulation between different sides to the encounters. The other theme I highlight is that heterogeneity within tourists' and visited people's home ideological formations is critical to their tourism involvement, such that endosocial and exosocial processes are mutually constitutive. I lastly outline how the category ‘primitivism’ is a useful resource for situating this tourism in wider and deeper historical contexts.  相似文献   

10.
Much anthropology has considered the social embeddedness of medical systems, personnel, and practices and the political subjectivities that may arise among health workers. I explore what medical citizenship looks like under conditions of settler colonialism in West Papua based on an ethnographic study of Dani (Balim) and Lani HIV nurses and NGO volunteers who see themselves and their activities as part of a broader effort to save Papuans from extinction. In particular, HIV work emerges as a biosocial obligation, meaning that workers give their expertise, attention, compassion, and treatment networks to people with HIV in the name of ensuring the vitality of the wider population, but giving care is not altruistic. As HIV workers respond to erasure, constraints, and racism, they put themselves at the centre of HIV care webs. ‘Traditional’ technologies transform healthcare encounters and challenge strategic ignorance about the epidemic. A close navigation of global health and settler power allows for flexible, independent, even surreptitious HIV practices that are deceptively radical and disruptive. Papuan HIV workers’ medical citizenship is encompassed by and expresses vernacular sovereignties.  相似文献   

11.
Vienne  C.  Soroker  V.  Hefetz  A. 《Insectes Sociaux》1995,42(3):267-277
Summary In homospecific groups of ants, each species has its own hydrocarbon profile, on the epicuticle and in the postpharyngeal gland (PPG). When reared together in bispecific groups, workers of both species possess each other's hydrocarbons in both locations. The present study investigated two alternative mechanisms by which a mixed odour in artificial groups ofFormica selysi/Manica rubida can be created. Using [1-14C] sodium acetate as a precursor,de novo biosynthesis of hydrocarbons was demonstrated for both species whether reared in homospecific or mixed-species groups. The newly synthesized hydrocarbons occurred on the epicuticle, internally, and in particularly large amounts in the PPG. As expected from their PPG and epicuticular hydrocarbons composition, workersF. selysi synthesized alkanes and alkenes in comparable amounts irrespective of their rearing scheme. Likewise,M. rubida reared in bispecific groups synthesized mostly alkanes with only negligible amounts of alkenes, according to a ratio characteristic toM. rubida workers from homospecific groups and not toF. selysi workers. During dyadic encounters, a transfer of labeled hydrocarbons between nestmates (conspecific in homospecific groups and allospecific in mixed groups) was observed. These results suggest that the formation of the mixed hydrocarbon profile in artificial groups of ants is the result of a transfer of these chemicals between nestmates rather thande novo biosynthesis of the allospecific hydrocarbons. Behaviours like trophallaxis, grooming and body contact that occurred during the encounters mediated such a transfer.  相似文献   

12.
Previous work has shown that the contact inhibition that occurs among roots of Ambrosia dumosa shrubs has a self/nonself recognition capability. In the current study, we investigated some of the geographic and genotypic dimensions of this recognition capability by using root observation chambers to observe the effects of encounters of individual roots on root elongation rates. We measured such effects in encounters between roots of plants from the same region and compared these to effects in encounters between roots of plants from two different regions. We also measured effects of encounters between roots of plants from the same clones and compared these to effects of encounters of roots of plants from different clones. Roots of plants from the same region (population) showed the usual “nonself” precipitous decline in elongation rates following contact, but when roots of plants from different regions contacted each other, elongation rates continued unchanged. When roots of separate plants from the same clone contacted each other, the same “nonself” precipitous decline in elongation rates as seen in encounters between roots of plants of different clones from the same region occurred. Meanwhile, in these same experiments “self” contacts between sister roots connected to the same plants resulted in no changes in elongation rates. Thus, differences between individuals from two geographically separate populations of Ambrosia dumosa may be sufficient to thwart the “nonself,” population-level recognition of similarity apparently necessary for contact inhibition. Furthermore, the “self” recognition mechanism, which precludes contact inhibition between two roots on the same plant, appears to be physiological rather than genetic in nature.  相似文献   

13.
Field studies in various species ofMacaca (Cercopithecidae) provided evidence for specific visual displays that typically accompany playful interactions. The aim of our study was to examine whether and when playing individuals would use auditory displays, i.e. vocalizations that often occur during social play as well. The study was conducted on a population of semi-free Barbary macaques (Macaca sylvanus) with a special focus on the composition and dynamics of playful wrestling (synonymous term: ‘rough-and-tumble play’). Analyses of dyadic encounters between subadult males allowed us to distinguish five types of playful behaviours and three types of vocalizations. The latter were clearly linked to encounters where effects of visual signals were impaired, e.g. during close body contact. During wrestling, vocalizations tended to increase in the beginning of an encounter, whereas the last seconds of wrestling often showed a decline in vocalization rate. Our results allowed us to conclude that these vocalizations may supplement or in many cases even substitute interactional effects of visual signals, e.g. the ‘play face.’  相似文献   

14.
Recent debate on the nature of probabilities in evolutionary biology has focused largely on the propensity interpretation of fitness (PIF), which defines fitness in terms of a conception of probability known as “propensity”. However, proponents of this conception of fitness have misconceived the role of probability in the constitution of fitness. First, discussions of probability and fitness have almost always focused on organism effect probability, the probability that an organism and its environment cause effects. I argue that much of the probability relevant to fitness must be organism circumstance probability, the probability that an organism encounters particular, detailed circumstances within an environment, circumstances which are not the organism’s effects. Second, I argue in favor of the view that organism effect propensities either don’t exist or are not part of the basis of fitness, because they usually have values close to 0 or 1. More generally, I try to show that it is possible to develop a clearer conception of the role of probability in biological processes than earlier discussions have allowed.  相似文献   

15.
The effect of macromolecular crowding on the rates of association reactions are investigated using theory and computer simulations. Reactants and crowding agents are both hard spheres, and when two reactants collide they form product with a reaction probability, prxn. A value of prxn < 1 crudely mimics the fact that proteins must be oriented properly for an association reaction to occur. The simulations show that the dependence of the reaction rate on the volume fraction of crowding agents varies with the reaction probability. For reaction probabilities close to unity where most of encounters between reactants lead to a reaction, the reaction rate always decreases as the volume fraction of crowding agents is increased due to the reduced diffusion coefficient of reactants. On the other hand, for very small reaction probabilities where, in most of encounters, the reaction does not occur, the reaction rate increases with the volume fraction of crowding agents—in this case, due to the increase probability of a recollision. The Smoluchowski theory refined with the radiation boundary condition and the radial distribution function at contact is in quantitative agreement with simulations for the reaction rate constant and allows the quantitative analysis of both effects separately.  相似文献   

16.
Plectroctena minor workers have long mandibles that can snap and deliver a sharp blow to intruders or prey, stunning or killing them. Encounters between homocolonial P. minor workers separated for 24 h or 15 days never resulted in snapping, while this behaviour was always noted during encounters between heterocolonial workers on neutral arenas or on the territory of a colony. In the latter case, only the aliens, that generally tried to escape, were snapped at. Snapping also occurred during encounters with workers belonging to sympatric ponerine species. During predation, the percentages of snapping varied according to prey nature, suggesting prey discrimination. Termite soldiers were always snapped at, while other prey were more often snapped close to rather than far from the nest entrances, indicating an intermingling of territorial aggressiveness and predatory behaviour. We discuss the adaptive value of snapping for hunting in galleries.  相似文献   

17.
Gene exchange between species occurs in areas of secondary contact, where two species have the opportunity to hybridize. If heterospecific males are more common than conspecific males, females will experience more encounters with males of other species. These encounters might increase the likelihood of heterospecific matings, and lead to the production of hybrid progeny. I studied the mating behavior of two pairs of sibling species endemic to Africa: Drosophila yakuba/Drosophila santomea and Drosophila simulans/Drosophila sechellia. Drosophila yakuba and D. simulans are cosmopolitan species widely distributed in the African continent, while D. santomea and D. sechellia are island endemics. These pairs of species hybridize in nature and have the potential to exchange genes in natural conditions. I used these two pairs of Drosophila species, and constructed mating communities of different size and different heterospecific:conspecific composition. I found that both the total number of potential mates and the relative frequency of conspecific versus heterospecific males affect female mating decisions in the cosmopolitan species but not in the island endemics. These results suggest that the population characteristics, in which mating occurs, may affect the magnitude of premating isolation. Community composition might thus facilitate, or impair, gene flow between species.  相似文献   

18.
In social insects, information on the presence of a queen is known to affect the reproductive behaviour of workers. In the queenless ant Diacamma sp., information of the presence of the gamergate, the functional queen, is transmitted exclusively by direct physical contact between the gamergate and workers. Periodic contacts between the gamergate and each worker are therefore necessary to maintain worker sterility. However, how the difference in the contact interval influences reproductive behaviour of workers is unclear. In the present study, by artificially controlling the exact interval of physical contact between workers with the gamergate, it is shown that the inter‐contact interval influences the worker's reproductive condition (i.e. a longer interval leads to more developed ovaries). This system provides a good opportunity to study the mechanisms underling the colony size dependence of individual as well as colony characteristics.  相似文献   

19.
Anthropologists and others have always used the Other to define themselves. Using Michael Taussig's idea of ‘second contact’, I argue that this is inappropriate and that the imagined borders between us and them in relationships between Vietnamese and other Australians are less than stable, continually losing their polarity and swimming in and out of focus. In light of the Vietnamese migrant case, I argue that similar ethnographic research projects cannot rely on stable boundaries between the host and the migrant community to organise explanations. Rather than simply registering ‘cultural contacts’, we have to engage the interplay between the strange and the familiar in specific contexts. Furthermore, my reading of Vietnamese migrant identity obliges us to listen to Vietnamese Australian voices as they attempt to respond to the fluctuating interstices of an intercultural borderland. This implies the mutual anthropological interrogation of both self and other.  相似文献   

20.
Resource competition and disease transmission may occur when domestic and wild ungulates live sympatricly. We investigated if the release of sheep (Ovis aries) onto alpine pasture in Switzerland affected chamois (Rupicapra rupicapra) activity budgets, local population size and spatial distribution. We also evaluated the risk of transmission of Mycoplasma conjunctivae (causing a contagious eye disease) from sheep to chamois by examining if the two species had close contact with one another. We carried out the study in an alpine valley containing two adjacent areas: one containing sheep (Fochsenflue) and one where sheep were excluded (Spitzflue). We found no difference between the activity budgets of the chamois at the two sites. At the Fochsenflue, chamois and sheep mainly used separate areas. However, after approximately 1 month, sheep started to move twice per day, into the main area of the chamois. The percentage time feeding, spatial distribution and numbers of chamois did not change in response. Sheep were responsible for all encounters in which the two species came closer than 50 m to each other. The encounters were brief, body contact never occurred, they were not concentrated at saltlicks and chamois mainly ended them. The results suggest that the presence of sheep had little effect on the chamois. However, competition between the two species could still be occurring over a longer time scale. Finally, we found that the risk of inter-specific transmission of IKC through direct body contact is likely to be low, but the risk through indirect means (flies or aerosols) remains.  相似文献   

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