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1.
S. T. C. Ootes A. J. Pols E. H. Tonkens D. L. Willems 《Culture, medicine and psychiatry》2013,37(1):131-147
Deinstitutionalisation has not only made the social inclusion of clients a key objective in long-term mental healthcare, it may also affect the role of the care professional. This article investigates whether the social inclusion objective clashes with other long-standing professional values, specifically when clients give gifts to care professionals. In making a typology of gifts, we compare the literature on gift-giving with professional codes for gifts and relate both to the objective of social inclusion of clients. Our typology draws on an analysis of ethnographic fieldwork carried out in 2007/2008 at a Dutch mental healthcare centre. We identify four types of gifts for professionals in long-term mental healthcare, each relating individually to professional codes and the objective of social inclusion of clients. Only the ‘personal gift’ directly supports social inclusion, by fostering personal relationships between professionals and clients. Acceptance of this type of gift is advocated only for long-term care professionals. We suggest that professional codes need to consider this typology of gifts, and we advocate promoting reflexivity as a means of accounting for professional behaviour in deinstitutionalised care settings. 相似文献
2.
We present a series of prospective models of nuptial feeding, mainly for insects. The models examine various optimal male and female strategies, but do not include any element of mate choice in which the female chooses males in relation to the gift he provides. We find that the female should use the gift to enhance egg size and/or clutch size when gifts represent a relatively large component of the energy resources for the gametes, or when the gift occurs at a relatively late stage in her reproductive cycle. However, if the female receives a single, relatively small gift during her reproductive cycle, she should show a reduced gametic output at the next oviposition. A literature survey revealed several studies that show increases in egg and clutch sizes following gift donation, but we found no instances in which there was a reduction in gametic output. We also find that if gifts are infrequent, there can be significant sexual conflict over the pattern of allocation of donated resources to future offspring. Male interests will generally be best served by a more immediate use of the resources than will be optimal for the female. This may result in selection for male ability to influence vitellogenesis and/or oviposition. Evidence is available which shows that male-derived substances influence female physiology; this might reflect an outcome towards male interests as a result of an arms race in sexual conflict. Some studies have demonstrated an effect of gift donation on survivorship. We examine models in which gift donation reduces male survival but increases female survival. These suggest that gift donation is most likely to evolve when (1) giving a gift has little effect on male, but a significant effect on female survival, (2) when the male is more likely to father eggs in a later batch, rather than the next batch, and (3) when random mortality is high. 相似文献
3.
Tina Andersen Kristine Bollerup Søren Toft & Trine Bilde 《Ethology : formerly Zeitschrift fur Tierpsychologie》2008,114(8):775-781
Males of the spider Pisaura mirabilis present a nuptial prey gift to the female during courtship as a mating effort. The gift is usually round and wrapped in white silk. It was suggested that the wrapped gift functions as a sensory trap by mimicking the female's eggsac implying that males exploit the female maternal care instinct and not her foraging motivation in a sexual context. The shape of the gift (round) and appearance (white) should then increase female acceptance of males. We tested these predictions experimentally and found that neither gift shape (round or oblong) nor silk wrapping (wrapped or unwrapped) facilitated female acceptance, in contrast unwrapped gifts were accepted faster than wrapped ones. Instead, we found that silk wrapping benefited the males because it significantly decreased the risk of females stealing the gift without copulation and consequently directly increased male mating success. Large oblong gifts were difficult for males to handle during copulation, resulting in shorter copulations for oblong vs. round gifts. Thus, round gifts were not preferred by the females but were beneficial to the males. Our results indicate two adaptive benefits to males of wrapping the nuptial gift: to reduce the risk of losing the gift to females without copulation, and make it possible to reshape an oblong prey into a round gift that facilitates the male's access to the female's genitalia. Our results suggest that the male gift wrapping trait may be selected though sexual conflict over remating rate. 相似文献
4.
In nuptial gift-giving species females sometimes select their potential mates based on the presence and size of the gift. But in some species, such as the Neotropical polyandrous spider Paratrechalea ornate male gifts vary in quality, from nutritive to worthless, and this male strategy can be in conflict with female nutritional benefits. In this species, males without gifts experience a reduction in mating success and duration, while males that offer worthless or genuine nutritive gifts mate with similar frequencies and durations. The female apparently controls the duration of copulation. Thus, there is scope for females to favour males offering gifts and further if these are nutritious, via post-copulatory processes. We first tested whether females differentially store sperm from males that offer the highest nutritional benefits by experimentally presenting females with males that offer either nutritive or worthless gifts (uninterrupted matings). Second, we carried out another set of experiments to examine whether females can select sperm based only on gift presence. This time we interrupted matings after the first pedipalp insertion, thus matching number of insertions and mating duration for males that: offered and did not offer gift. Our results showed that the amount of sperm stored is positive related to mating duration in all groups, except in matings with worthless gifts. Gift presence itself did not affect the sperm stored by females, while they store similar number of sperm in matings with males offering either nutritive or worthless gifts. We discuss whether females prefer males with gifts regardless, if content, because it represents an attractive and/or reliable signal. Or alternatively, they prefer nutritive nuptial gifts, as they are an important source of food supply and/or signal of male donor ability. 相似文献
5.
Mating is often accompanied by decreased female immune function across numerous animals systems, suggesting that immune suppression is a widespread reproductive cost. However, the trade‐off between immunity and reproduction can be minimized when females have access to abundant nutrient resources. This observation suggests that the nuptial gifts provided by males in many insect systems may help to offset the common immunological cost to reproduction. In the present study, this hypothesis is tested in the ground cricket Allonemobius socius (Scudder), whose females receive a sizeable haemolymph‐based gift. Accordingly, male gift donation is controlled by covering the tibial spur (the source of the gift) of randomly chosen males with clear nail polish. The influence of sperm transfer on female immunity is disentangled from that of the nuptial gift by also examining females who fail to receive sperm during mating (spermatophore transfer has a 40% failure rate in virgin males). It is predicted that females who receive a nuptial gift will exhibit superior immune function compared with those who receive no gift. The results show that sperm transfer reduces female immune function, which is an expected immunological cost of reproduction. By contrast to the prediction, nuptial gifts do not minimize the immunological cost of reproduction in this system. Unexpectedly, the receipt of a gift appears to decrease female immune function independent of sperm transfer. The findings suggest that the nuptial gift, similar to sperm, signals the female to begin her reproductive investment, causing limited resources to be reallocated from immune function. 相似文献
6.
A C Mermann 《The Yale journal of biology and medicine》1992,65(2):137-142
Dying is an event beyond our comprehension, an experience that can only be imagined. Patients with cancer have a gift denied many others: some time to prepare for the approaching end of life. This time can be used to bring old conflicts to a close, to say goodbye and seek forgiveness from others, to express love and gratitude for the gifts of a life. Physicians can help patients by being aware of the spiritual dimensions to life that many patients have. In major religious traditions, death is accepted as the natural end of the gift of life and as a point of transition to another, yet unknown, existence. For many patients, it is not death that is feared, but abandonment. The physician's awareness of the spiritual needs of patients can make care of the dying more rewarding and fulfilling for all concerned. 相似文献
7.
Nina Wedell 《Evolution; international journal of organic evolution》1993,47(4):1203-1212
During courtship and copulation, males of many insect species provide the female with a nuptial gift of a prey item or synthesized material. These gifts may be explained as a form of paternal investment by increasing female reproductive output, or in terms of mating effort by increasing male fertilization success. These explanations, while not mutually exclusive, are controversial. While experimental studies examine the maintenance of nuptial gifts in single species, comparative studies are required to indicate more general evolutionary trends. Male bushcrickets provide females with a nuptial gift, a spermatophylax, which is transferred to females at mating along with the sperm-containing ampulla. Analysis of comparative data of 28 species of bushcrickets (Orthoptera: Tettigoniidae), reveals that male spermatophore size (spermatophylax and ampulla weight) is positively correlated with female refractory period, which, in turn, correlates with male fertilization success. Moreover, gift size (the spermatophylax) covaries with ejaculate size (the ampulla), which is consistent with the hypothesis that it serves as a sperm protection device. In contrast, there is no significant correlation between any measure of female fecundity and male spermatophylax size. This indicates that the variation in spermatophore size among bushcrickets is better explained by a mating-effort function than a paternal investment function. 相似文献
8.
Sexual selection in the gift-giving dance fly, Rhamphomyia sulcata, favors small males carrying small gifts 总被引:1,自引:0,他引:1
LeBas NR Hockham LR Ritchie MG 《Evolution; international journal of organic evolution》2004,58(8):1763-1772
In some species of insects males transfer a gift to females during courtship or copulation. In the dance flies these nuptial gifts vary from nutritious prey items to inedible tokens such as a leaf, stone, or silk balloon. Nuptial gifts in dance flies are presumed to increase male mating success. We examined the strength and form of sexual selection on male Rhamphomyia sulcata, an empidid in which males provide females with a nutritious prey item as a nuptial gift. We found that whereas large males carried large gifts, neither large males nor gifts were targets of sexual selection. Indeed, correlational selection analysis and nonparametric examination of the fitness surfaces revealed that small males carrying small gifts were the most successful. Males may be more maneuverable or flight efficient with small gifts, or small males with large gifts may be unable to carry both a large gift and a female in the paired descent flight. These results suggest carrying constraints may be an important factor in determining selection on nuptial gift size. The largest target of sexual selection was old males. Old males were also paired with the largest and most fecund females, highlighting the role mate quality can further contribute to selection on males. Correlational selection analysis also revealed selection for an increase in covariance between male wing length and body size, and for an increase in slope between these traits. Males who deviate away from the optimal phenotypic relationship for two tightly related morphological traits, such as tibia and wing length, may have overall reduced performance. These findings highlight the role correlational sexual selection can play in optimizing nonsexual male morphology and scaling relationships. This study questions the role of the nuptial gift in dance flies as a resource for females. 相似文献
9.
Nuptial gifts are food items or inedible tokens that are transferred to females during courtship or copulation . Tokens are of no direct value to females, and it is unknown why females require such worthless gifts as a precondition of mating. One hypothesis is that token giving arose in species that gave nutritious gifts and males exploited female preferences for nutritional gifts by substituting more easily obtainable but worthless items. An invasion of such behavior would require that females accept the substitute gift and copulate for a period of time similar to that with genuine gifts. We show that both these prerequisites are met in the dance fly Rhamphomyia sulcata, in which females normally accept a nutritious gift. We removed the gift from copulating pairs and replaced it with either a large or small prey item or inedible token. We found that although pairs copulated longest with a large genuine gift, the tokens resulted in copula durations equivalent to those with a small genuine gift. We also observed that males that returned to the lek with tokens re-paired successfully. These findings suggest that female behavior in genuine gift-giving species is susceptible to the invasion of male cheating on reproductive investment. 相似文献
10.
Abstract 1. Male Panorpa scorpionflies offer salivary masses as nuptial gifts during copulation. Previous studies have shown that there is usually a strong correlation between the number or size of salivary masses provided and copulation duration. As a result of constant sperm transfer rates, copulation duration is the most important determinant of male fitness in these species. 2. Differences in copulation durations for gift‐giving and non‐gift‐giving males of the Caucasian scorpionfly Panorpa similis have been shown to be much smaller on average than those observed in other Panorpa species. In this study, we therefore focus on the number of sperm transferred in copulations of P. similis both with and without salivary masses. 3. We find that although the average copulation duration in the presence of nuptial gifts is only twice as long as the average copulation duration without nuptial gifts, gift‐giving males transfer almost 11 times more sperm during copulations than non‐gift‐giving males. This is as a result of substantially higher sperm transfer rates (sperm/minute) in copulations in which nuptial gifts are present. 4. Implications of this finding for the interpretation of the mating system of P. similis and the question of which sex controls sperm transfer rates are discussed. 相似文献
11.
Leif Engqvist 《Evolutionary ecology》2007,21(1):49-61
In the scorpionfly Panorpa cognata, males provide females with saliva secretions as nuptial food gifts. Consequently, females derive material benefits and possibly
also genetic benefits from multiple matings. Females therefore generally should have a high motivation to remate. Males, on
the other hand, do not share this interest, which will generate a sexual conflict over remating interval, possibly leading
to male adaptations that prevent females from remating with other males. In this study, I found that mated females were less
prone to copulate than virgin females, despite female benefits of multiple matings. Further, I found that the remating interval
was significantly longer if the first copulation was long compared to shorter matings. This effect does not entirely depend
on copulation duration per se, but on the amount of saliva, that a female is consuming during copulation. These results suggest
a mating-induced refractory period and can be interpreted as male manipulation of female remating behaviour mediated through
substances in the nuptial gift. Alternatively, receiving large nuptial gifts may decrease the prospective direct fitness benefits
from further copulations, and thus change optimal female remating rate. Furthermore, gift size has been shown to correlate
with male nutritional condition, which may be an indicator of male genetic quality. Females may therefore benefit indirectly
by not remating following copulations involving large saliva gifts. In this scenario, female remating interval would be an
effect of cryptic female choice. 相似文献
12.
Asuka Komiya Yohsuke Ohtsubo Daisuke Nakanishi Shigehiro Oishi 《Evolution and human behavior》2019,40(2):160-166
The present study explored why married couples periodically exchange gifts. Based on the commitment signal hypothesis, we tested whether relational mobility, which was operationalized as divorce rate in Study 1 and relational opportunities in Study 2, is positively correlated with the frequency of gift exchanges among married couples. In Study 1, we found that married couples in the U.S., which is associated with a relatively high divorce rate, were more likely to give and receive gifts to and from their partners than those in Japan, which is associated with a relatively low divorce rate. This societal difference, in contrast, was not observed among unmarried couples, who were still developing their relationship (and thus, partner changes could frequently happen regardless of the country-level divorce rate). Study 2, a secondary analysis of extant survey data, revealed that Japanese married couples who have more relational opportunities more frequently engage in gift exchanges than those who do not. Together, these results support our hypothesis that periodical gift exchanges work as commitment signals among married couples. 相似文献
13.
All that Glisters is not Gold: Sensory Bias, Sexual Conflict and Nuptial Feeding in Insects and Spiders 总被引:8,自引:0,他引:8
Karim Vahed 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(2):105-127
It is becoming increasingly clear that the evolutionary interests of the sexes are often in conflict when it comes to mating. Sexual encounters involving nuptial gifts, however, have often been viewed as prime examples of sexual co‐operation, rather than conflict. In this review, I explore the proposition that nuptial gifts act as sensory traps: by exploiting the female's gustatory responses, the male may be able to entice females to accept superfluous matings and/or transfer greater volumes of ejaculate than are in the female's reproductive interests. Evidence suggests that the females’ sensory biases may have played an important role in shaping gift characteristics in at least four different systems, although relatively few forms of nuptial feeding have so far been examined from this perspective. I argue that gift composition is more likely to be tailored to increasing the attractiveness of the gift to the female and/or maximizing gift handling time than to suit the female's nutritional needs and that the fecundity‐enhancing benefits of nuptial gifts are often questionable and have been over‐stated in the literature. Fertilization biases associated with the female's attraction to the nuptial gift, however, could lead to in‐direct benefits for the female. On the other hand, nuptial feeding may also lead to significant costs to the female. Evidence suggests that some types of gift entice the female to mate, but it is not clear whether the resultant degree of polyandry is higher than optimal for the female. In other cases, evidence suggests that the gift enables the male to overcome the resistance of the female to accepting an extra large ejaculate and that large ejaculates are associated with longer post‐mating sexual refractory periods in the female. This could represent a cost to the female by delaying or preventing her from receiving the genetic benefits of polyandry. At present, it is not clear, however, whether such costs outweigh the potential benefits of nuptial feeding for the female. 相似文献
14.
Men, like the male of many animal species, use gifts to build satisfactory relationships with a desired woman. From the woman’s perspective, all gifts are not always equally rewarding; the reward value of a gift depends on two factors: (1) the giver and (2) the type of the gift (the gift’s social meaning). In this study, we investigated how these two factors interactively determine the reward value of a gift. Specifically, we examined how the neural processing for understanding a gift’s social meaning is modulated by preferences for the giver. We performed a functional magnetic resonance imaging (fMRI) study in which a female participant was asked to judge a gift from a male she was acquainted with in real life. We examined the interactive effects between (1) the female participant’s attitude toward the male acquaintance (liked vs. uninteresting) and (2) the type of the gift (romantic [e.g., bouquet, earrings, and perfumes] vs. non-romantic [e.g., pencils, memo pad, and moneybox]). We found that preference for an acquaintance selectively modulated activity in the anterior cingulate cortex (ACC) in response to romantic gifts, compared to non-romantic gifts. In contrast, if the woman was indifferent toward an acquaintance, no activity modulation was observed in this area for the same gifts. In addition, the ACC showed functional connectivity with the supplementary motor area/dorsal ACC (SMA/dACC), an area within the dorsal mediofrontal cortex, suggesting that it integrates action monitoring and emotional and cognitive processing in decision-making. These results suggest that attitude toward an opposite sex member has a modulatory role in recognizing the social meaning of material goods—preference for the member is a powerful modulator of social reward processing. 相似文献
15.
Nuptial gifts and the evolution of male body size 总被引:4,自引:0,他引:4
In many insect systems, males donate nuptial gifts to insure an effective copulation or as a form of paternal investment. However, if gift magnitude is both body size-limited and positively related to fitness, then the opportunity exists for the gift to promote the evolution of large male size. In the striped ground cricket, Allonemobius socius, males transfer a body size-limited, somatic nuptial gift that is comprised primarily of hemolymph. To address the implications of this gift on male size evolution, we quantified the intensity and direction of natural (fecundity) and sexual (mating success) selection over multiple generations. We found that male size was under strong positive sexual selection throughout the breeding season. This pattern of selection was similar in successive generations spanning multiple years. Male size was also under strong natural selection, with the largest males siring the most offspring. However, multivariate selection gradients indicated that gift size, and not male size, was the best predictor of female fecundity. In other words, direct fecundity selection for larger gifts placed indirect positive selection on male body size, supporting the hypothesis that nuptial gifts can influence the evolution of male body size in this system. Although female size was also under strong selection due to a size related fecundity advantage, it did not exceed selection on male size. The implications of these results with regard to the maintenance of the female-biased size dimorphic system are discussed. 相似文献
16.
Stålhandske P 《Proceedings. Biological sciences / The Royal Society》2002,269(1494):905-908
While nuptial food gifts come in various forms in arthropods, their evolutionary origins are unclear. A previous study on insects has shown that such gifts may arise as a sensory trap that exploits a female's underlying motivation to feed. Here I present independent evidence of a sensory trap in spiders. In certain visually oriented spiders, I suggest that males initially exploit the maternal care instinct by producing a nuptial gift that closely resembles the female egg sac. Males of the spider Pisaura mirabilis cover their prey gift with a silk layer, transforming it into a white round object. In a laboratory experiment I tested whether the colour of the gift affected the rate that females accepted males displaying their gifts. I found that the brighter and the more alike the nuptial gift to a female's egg sac, the faster the female responded by grabbing the gift. My results support the hypothesis that the nuptial gift in P. mirabilis works as a sensory trap. 相似文献
17.
Xingyue Liu Fumio Hayashi Laura C. Lavine Ding Yang 《Proceedings. Biological sciences / The Royal Society》2015,282(1807)
Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male–male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals. 相似文献
18.
In many species that have internal fertilization, seminal flow includes various elements and materials in addition to the
fertilizing sperm. The roles of these components are unknown. One hypothesis is that they are nutritional gifts to the female
as a paternal investment. We made game theoretical models from the point of view of sperm competition among males and examined
this hypothesis. The evolutionary stable strategy (ESS) of the models showed that (1) when multiple mating in the female is
relatively low, gifts in seminal flow or other types of gift may evolve, at least, a male does not resist a female digesting
his sperm; and (2) the ratio of nutritional gift rapidly decreases to zero with the probability or frequency of multiple mating
in the female. Hence, we concluded that nutritional gifts in seminal flow can exist only in species in which sperm competition
among males is rare. Furthermore, we concluded that if an element or material eminently decreases when sperm competition becomes
intense, it may be a gift as a paternal investment; if not, other hypotheses concerned with more agonistic roles are more
feasible.
Received: November 6, 2000 / Accepted: January 10, 2001 相似文献
19.
André J. Szameitat Yasmin Hamaida Rebecca S. Tulley Rahmi Saylik Pauldy C. J. Otermans 《PloS one》2015,10(10)
Reports in public media suggest the existence of a stereotype that women are better at multitasking than men. The present online survey aimed at supporting this incidental observation by empirical data. For this, 488 participants from various ethnic backgrounds (US, UK, Germany, the Netherlands, Turkey, and others) filled out a self-developed online-questionnaire. Results showed that overall more than 50% of the participants believed in gender differences in multitasking abilities. Of those who believed in gender differences, a majority of 80% believed that women were better at multitasking. The main reasons for this were believed to be an evolutionary advantage and more multitasking practice in women, mainly due to managing children and household and/or family and job. Findings were consistent across the different countries, thus supporting the existence of a widespread gender stereotype that women are better at multitasking than men. Further questionnaire results provided information about the participants’ self-rated own multitasking abilities, and how they conceived multitasking activities such as childcare, phoning while driving, and office work. 相似文献
20.
Alice Wilson 《Ethnos》2018,83(2):296-315
ABSTRACTEnduring scholarly interest in the social relations of gift exchange has, following Mauss, emphasised how gifts make relationships. Where gifts break relationships, their ethnographic distinctiveness has reinforced the wider notion that gifts are good at making relations. This article examines gifts which, without the empirical distinctiveness of gifts that break relationships, both make and break relationships. Speakers of the Hassaniya dialect of Arabic in north-west Africa give post-marital gifts from the bride’s to groom’s party; these gifts became highlighted amongst Sahrawi refugees in Algeria, on whom the article focuses. In addition to performing reciprocity, boosting the giver’s honour and making new affinal relations, these post-marital gifts also break the relationship between the bride’s family and the bride. The article argues that gifts’ potential to recalibrate relationships through both making and breaking relationships can be helpfully incorporated into wider thinking about gifts, alongside other distinctions amongst gifts and gift relations. 相似文献