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1.
This article argues that the instability of social arrangements, openness in economic strategies, and presentist orientations found among the Calon Gypsies (Ciganos) in Bahia are not to be attributed to uncertainty originating in destabilizations of Calon social life through encompassment and penetration by the dominant Juron (non-Gypsy) society. It shows instead that Calon cultivate exploitable uncertainty and maintain forward thrust in their lives through a form of self-discipline sometimes described as ‘making the future’, which distinguishes them from both Jurons and those Calon who have died. This orientation, which highlights the unsettlement of existing arrangements in order to create new opportunities and alter one's position, is inseparable from Calon conceptions regarding generations and gender. It provides a performative background against which Calon can demonstrate attributes of social persons and allows for ‘enchaining’ people through recomposing relationships.  相似文献   

2.
Variation among individuals in the expression of behaviors and associations of behaviors in different contexts can lead to the maintenance of behavioral polymorphisms. Individual variation in morphology is often associated with behavioral polymorphism, yet the degree to which morphology predicts behavioral phenotype is not well understood. We measured individual variation in size and behaviors in the sailfin molly, Poecilia latipinna, by comparing the behavior of individual males of different sizes across four different contexts (mating, exploratory tendency, sociability, and predator inspection). We also investigated the degree to which male size, a fixed genetic trait, influenced the expression of each behavior and associations between behaviors. We found that male mollies show strong associations between certain behaviors and only some of these are predicted by male size. For example, size has a strong influence on the courtship‐boldness axis with larger males showing higher rates of courtship displays and being bolder in predator inspection. A positive association was found between exploratory tendency, sociability, and gonopodial thrusting rates, yet the expression of these behaviors was independent of male size. Thus, sailfin mollies, like many fish species, show associations of behaviors that contribute to differences among males in personality type. The fixed genetic effect of male size at maturity influences courtship and boldness, but individual variation in exploratory tendency, sociability, and sneak copulation attempts through gonopodial thrusts is independent of male size. Such variation among males in behavioral associations within and between different contexts may slow the rate at which populations of Platipinna can diverge in individual behaviors.  相似文献   

3.
The study of child abuse and child homicide has been based on the often implicit assumption that there is a continuum of violence ranging from mild physical punishment to severe abuse and homicide. Empirical data supporting this assumption are sparse. Existing data can be shown, however, to support an assumption that there are distinct forms of violence, not a continuum. This paper reviews these data and discusses their implications for the study of violence, abuse, and homicide in terms of substantive and methodological explanations. In addition, the implications of the assumption that violence consists of distinct behaviors as opposed to a continuum are discussed in light of sociobiological and evolutionary explanations of child abuse and child homicide. This paper was written under the auspices of the Family Violence Research Program at the University of Rhode Island. A complete list of books and articles is available upon request. Richard J. Gelles is Professor of Sociology and Anthropology and the Director of the Family Violence Research Program at the University of Rhode Island. He is the author or coauthor of 14 books and more than 90 articles and chapters on family violence. His most recent books areIntimate Violence, published in 1988 by Simon and Schuster;Physical Violence in American Families: Risk Factors and Adaptations in 8,145 Families, published by Transaction Books in 1990; andIntimate Violence in Families, published in 1990 by Sage Publications.  相似文献   

4.
Most headhunting traditions in island Southeast Asia link ritual violence to grief and mourning. Some of the more persuasive analyses of these practices pivot on notions of rage and catharsis, arguing that turbulent emotions motivate persons to take up cleansing acts of violence. This paper seeks a more complex understanding of how ritual may connect bereavement and violence through a look at case materials from highland Sulawesi (Indonesia). Ritual practices there suggestthat the resolution of communal mourning is more significant than personal catharsis in motivating violence; that individual affect is refigured collectively as political affect; and that varied discursive forms, such as vows, songs, and noise mediate the ways in which people put grief behind them and resume their lives. Indeed, such discursive forms appear to be generative sites for violence and solace.  相似文献   

5.
The fossil record of early hominids suggests that their Arm length, and presumably stature and weight, had a tendency to increase. Using the minimum jerk principle and a related formulation of averaged specific power, ASP, with regard to selected two-joint Arm movements, the current paper explores relationships between ASP, hand trajectory length (or Arm length, or body mass) and mean movement speed, deriving relationships which indicate that ASP is proportional to cubic mean movement speed, but inversely proportional to hand trajectory length (or Arm length, or 1/3 power of body mass). Accordingly, an `ecological niche’ is modeled in a three-parameter space. Either ASP maximization for fixed movement time, or ASP minimization for fixed mean movement speed, taken as selective optimization criterion, allows the increasing of human Arm length during evolution, regardless of the arm-to-forearm length ratio.  相似文献   

6.
Abstract 1. Animals, as they move through their environment, leave traces of their passage that can be informative to others and convey significant advantages to the animal producing them. However, such traces may also reveal presence, location or identity to enemies. 2. We studied an araneophagic (‘spider‐eating’) assassin bug, Stenolemus bituberus (Heteroptera, Reduviidae), testing whether it associated with areas containing chemotactile traces (e.g. draglines, excreta) left behind by nine sympatric spider species. Stenolemus bituberus were presented with a choice between a substrate containing draglines and a clean substrate. Each hour, for a duration of 12 h, we recorded which substrate was occupied. 3. Stenolemus bituberus tended to associate especially with draglines left by spiders from the genus Achaearanea, their most common prey in nature. 4. These results suggest that S. bituberus exploits draglines from these spiders as cues for indicating prey presence. We also found an increasing tendency to associate with draglines from some spider species through the day, which may be related to circadian patterns or slower response times of some individuals.  相似文献   

7.
Two days after exposure of roots to15N labeled N2, partitioning of biologically fixed N into leaves, stems, peduncles, pods, roots and nodules was measured in the early pod development stage of cowpea (Vigna unguiculata (L.). The experimental objective was to determine the quantity of biologically fixed N that is incorporated into vegetative tissue before being mobilized to pods. For the three varieties of cowpea included in the experiment a maximum of 50% of the N, biologically fixed two days earlier, was contained in the pods. The remaining N was distributed throughout the vegetative portion of the plant with at least 30% in stems and leaves which indicates that much of the newly fixed N must cycle through a N pool in these tissues before reaching the pods.  相似文献   

8.
Beginning around 1800, but primarily since the early and mid-twentieth century, the giant African snail, Achatina (Lissachatina) fulica Bowdich, 1822, has been introduced throughout the tropics and subtropics and has been considered the most important snail pest in these regions. In Brasil, specimens probably brought from Indonesia were introduced into the state of Paraná in the 1980s for commercial purposes (“escargot” farming) that were not successful. Achatina fulica is now widespread in at least 23 out of 26 Brasilian states and the Federal District, including the Amazonian region and natural reserves. Among the reasons for the species’ rapid invasion are its high reproductive capacity and the tendency for people to release the snails into the wild. Achatina fulica occurs in dense populations in urban areas where it is a pest in ornamental gardens, vegetable gardens, and small-scale agriculture. Also of concern is the damage caused to the environment, and potential competition with native terrestrial mollusks. It can also act as an intermediate host of Angiostrongylus cantonensis, a nematode that can cause meningoencephalitis in people, and it may be a potential host of A. costaricensis, which causes abdominal angiostrongylosis, a zoonosis that occurs from the southern United States to northern Argentina. Management and control measures for A. fulica are under way in Brasil through a national plan implemented by the Brasilian government.  相似文献   

9.
Catherine Smith 《Ethnos》2015,80(2):272-291
ABSTRACT

This article explores the fears and desires that conflict survivors invest in biomedicine in post-conflict Aceh, Indonesia. After examining common criticisms of Acehnese doctors, I go on to discuss the practise of Acehnese medical travel to Malaysia and the desirable depictions of biomedicine that are generated through cross-border clinical encounters. Building on Pinto [2004. Development Without Institutions: Ersatz Medicine and the Politics of Everyday Life in Rural North India. Cultural Anthropology, 19(3):337–364], I argue that in the post-conflict period, biomedicine acts as both a site of terror and ‘point of imagination and longing’ that guides my interlocutors' understandings of the changing world around them. The article brings debates about medicine and violence into dialogue with a body of post-conflict ethnography, showing how popular imaginaries of biomedicine can shape the process of post-conflict world building.  相似文献   

10.
Somatic metaphase karyotypes were analyzed for 22 diploid species ofEupatorium. The karyotypic comparisons were made using two indices: minimal chromosomal distance (MCD), measuring overall dissimilarities, and chromosomal identity (CI), measuring number of morphologically identical chromosomes between species. The resulting phenograms from these indices are largely compatible. The 22 species cluster into four groups in the phenogram using MCD, and the grouping corresponds well with morphology or geographic distribution into the three N. American groupsEutrochium, Uncasia, Traganthes, and the E. Asian group. These results suggest that karyotypes in perennialEupatorium have been considerably conservative and changed not through large chromosomal mutations but through small chromosomal mutations gradually fixed.  相似文献   

11.
In Calicut populations of P. hydrodromous, the ovary is not refractory during September—November of the prebreeding season; it is inhibited from developing apparently by a gonad-inhibiting hormone(s) contained in the eyestalks. The prevalent tendency in Paratelphusa during the prebreeding season is to reproduce, and not to moult. The precocious ovarian growth induced by eyestalk removal during this season is biochemically impoverished, possibly due to uneven oocyte development, which in turn may be caused by the unpreparedness of a section of the population of oocytes for vitellogenesis. The ovary appears to have to pass through a period of oogonial proliferation under the influence of the moult-precipitating hormones during the moulting season, and subsequently through a period of oocyte differentiation during the prebreeding season, for normal vitellogenesis during the breeding season.  相似文献   

12.
Mucke L  Pitas RE 《Neuron》2004,43(5):596-599
Interactions between environmental and genetic factors may contribute to neurodegenerative disease. In this issue of Neuron, Calon et al. report that a diet low in an essential omega-3 polyunsaturated fatty acid (docosahexaenoic acid) depletes postsynaptic proteins and exacerbates behavioral alterations in a transgenic mouse model of Alzheimer's disease.  相似文献   

13.
Abstract

Culture is a fuzzy concept without fixed boundaries, meaning different things according to situations. To address this issue, I introduce a p-model to understand culture as a system of people, places, and practices, for a purpose such as enacting, justifying, or resisting power. People refers to population dynamics, social relations, and culture in groups. Places refers to ecological dynamics, institutional influences, and culture in contexts. Practices refers to participatory dynamics, community engagement, and culture in action. Power refers to forcing others into compliance (power-over people), controlling access to spaces (power in places), and behaving as desired (power-to practice). I use racism to illustrate the p-model and suggest applications in theory, research, and practice in developmental sciences.  相似文献   

14.
Long-styled (pin) and short-styled (thrum) plants in populations of Mitchella repens from North Carolina and New York displayed strongly clumped spatial dispersion. This distribution pattern results from the tendency of these prostrate perennials to spread by production of trailing stems with adventitious roots. Both morphs, in both populations, exhibited natural fruit set exceeding 86%. This percentage was not increased by hand-pollination. Although the number of ovules per pair of ovaries was fixed at eight in each morph, numbers of seeds per fruit in naturally pollinated flowers differed significantly between pins (4.3) and thrums (6.4) in the North Carolina population. In the New York population, no significant differences were found (pins had 5.0 seeds per fruit; thrums, 4.4). Artificial pollinations in both populations showed low seed set in intramorph cross-pollinations as compared with intermorph crosses. The flowers of M. repens were visited by native species of Bombus, which visited many flowers in each patch of plants. These insects moved frequently from patch to patch, effecting intermorph cross-pollination and maintaining high levels of seed set. Movement among patches may be promoted by the dispersion of nectar rewards, with flowers about to open or just opened providing maximum amounts of nectar. Calculations of functional gender suggested that in the North Carolina population, thrums contributed more than 75% of the genes transmitted by ovule production. This contrasts strongly with previous studies of unequal sexual contributions in distylous taxa, which have demonstrated greater female contributions by pins. In the New York population, however, nearly equal contributions by pins and thrums through pollen and ovule production occurred, a situation similar to that found in most distylous species. This appears to be the first demonstration of variation in functional gender between populations of a single species.  相似文献   

15.
Spironello M  Hunter FF 《Genetica》2005,123(3):217-226
The black fly subgenus Inseliellum is present on a series of archipelagos in the South Pacific. In this study, larval polytene chromosome maps of six Inseliellum species are presented. Chromosomal relationships among taxa were determined through shared fixed inversions or chromosomal landmark positioning. Three fixed inversions (IL-2, IIS-1, and IIIS-1) were shared among species, as was the position of the nucleolar organizer (NO) (IL or IIL). Comparisons to two previously studied species of Inseliellum are included to produce a cytological transformation series among eight taxa. The NO position defines two clades in the phylogeny of Inseliellum, herein named the NO-IL and NO-IIL clades. The utility of this cytological data set is discussed.  相似文献   

16.
Self splicing introns and inteins that rely on a homing endonuclease for propagation are parasitic genetic elements. Their life-cycle and evolutionary fate has been described through the homing cycle. According to this model the homing endonuclease is selected for function only during the spreading phase of the parasite. This phase ends when the parasitic element is fixed in the population. Upon fixation the homing endonuclease is no longer under selection, and its activity is lost through random processes. Recent analyses of these parasitic elements with functional homing endonucleases suggest that this model in its most simple form is not always applicable. Apparently, functioning homing endonuclease can persist over long evolutionary times in populations and species that are thought to be asexual or nearly asexual. Here we review these recent findings and discuss their implications. Reasons for the long-term persistence of a functional homing endonuclease include: More recombination (sexual and as a result of gene transfer) than previously assumed for these organisms; complex population structures that prevent the element from being fixed; a balance between active spreading of the homing endonuclease and a decrease in fitness caused by the parasite in the host organism; or a function of the homing endonuclease that increases the fitness of the host organism and results in purifying selection for the homing endonuclease activity, even after fixation in a local population. In the future, more detailed studies of the population dynamics of the activity and regulation of homing endonucleases are needed to decide between these possibilities, and to determine their relative contributions to the long term survival of parasitic genes within a population. Two outstanding publications on the amoeba Naegleria group I intron (Wikmark et al. BMC Evol Biol 2006, 6: 39) and the PRP8 inteins in ascomycetes (Butler et al. BMC Evol Biol 2006, 6: 42) provide important stepping stones towards integrated studies on how these parasitic elements evolve through time together with, or despite, their hosts.  相似文献   

17.
18.
The amount of carbon released into soil through root exudation byDigitaria adscendens Herrm. andAmbrosia artemisiifolia L. var.elatior Desc., which often predominate at the early stages of secondary succession, was evaluated in a laboratory experiment conducted over a 60-day period. Differences in the amount of exuded carbon between these species and between the developmental stages were examined. The amount of carbon exuded increased with growth in both species. The percentage of exuded carbon to photosynthetically net fixed carbon, which was higher at younger stages (13%) inD. adscendens, decreased to 3.1% with time. On the other hand, no reduction in the amount of carbon exuded was observed inA. artemisiifolia (4.7–8.1% range). The total amount of carbon released through root exudation inD. adscendens andA. artemisiifolia was estimated at 3.1% and 6.9% of photosynthetically net fixed carbon, respectively. These results suggest the possibility that wild plants exude a considerable amount of carbon from their roots to the soil, and emphasizes the necessity for considering root exudation in the carbon cycle.  相似文献   

19.
Proboscis monkeys,Nasalis larvatus (Wurmb), were investigated in the Padas Bay and Kinabatangan River areas, Sabah, from July 1968 to March 1969. The proboscis monkey is a common, widely distributed species of coloboids in Sabah, living in the various vegetations that extend from the coastal swamp to the inland plain. It appears to have a terrestrial tendency, compared with other coloboids, moving around on the ground in the forest and extending its activity, sometimes, to the open land along the river beach. The number of monkey in a troop, we observed, ranged from 11 to 32, and almost all troops were composed of several adult males, many more adult females, and immature animals. The adult males appear to play the role of leaders in the troop through their characteristic behavior, attacking, threatening, warning, watching, etc., other troop members or invaders. Each troop always emitted various boisterous vocalizations which were divided into 14 types.  相似文献   

20.
Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.  相似文献   

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