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排序方式: 共有241条查询结果,搜索用时 15 毫秒
1.
Objective: Obese children are stigmatized in same‐sex relationships. This study examines whether, in adulthood, obesity stigma exists in adults when they are asked to rank order preferences for a sexual partner. Research Methods and Procedures: Following the methods of Richardson et al. (Richardson SA, Goodman N, Hastorf AH, Dornbusch SM. Cultural uniformity in reaction to physical disabilities. Am Sociol Rev. 1961;26:241–247) and Latner and Stunkard (Latner J, Stunkard AJ, Wilson GT. Age, ethnic and gender differences in stigmatization of obesity. Orlando, FL: International Conference on Eating Disorders; 2004), 449 college students were asked to rank order six drawings of potential sexual partners. The drawings included an obese partner, partners with various other disabilities, and a healthy partner. Results: The least‐preferred partners were obese. Men, compared with women, provided significantly lower ranks for obese partners (U = 20, 180.00, z = ?2.84, p = 0.01). Discussion: Despite the fact that the majority of adults in the U.S. are overweight, discrimination on the basis of weight occurs in making a choice of a sexual partner. Males particularly make choices of partner based on their weight. Obesity stigma may specifically affect women in sexual relationships. Weight‐related stigma needs to be addressed in the treatment of binge eating disorder or weight management. Finding ways to change attitudes and behavior toward the overweight is a goal for future research in the area. 相似文献
2.
Weight Stigmatization and Ideological Beliefs: Relation to Psychological Functioning in Obese Adults
Kelli E. Friedman Simona K. Reichmann Philip R. Costanzo Arnaldo Zelli Jamile A. Ashmore Gerard J. Musante 《Obesity (Silver Spring, Md.)》2005,13(5):907-916
Objective: This study evaluated the relation among weight‐based stigmatization, ideological beliefs about weight, and psychological functioning in an obese, treatment‐seeking sample. Research Methods and Procedure: Ninety‐three obese, treatment‐seeking adults (24 men and 69 women) completed a battery of self‐report questionnaires measuring psychological adjustment, attitudes about weight, belief in the controllability of weight, and the frequency of weight‐based stigmatization. Results: Weight‐based stigmatization was a common experience for participants. Frequency of stigmatizing experiences was positively associated with depression, general psychiatric symptoms, and body image disturbance, and negatively associated with self‐esteem. Further, participants’ own negative attitudes about weight problems were associated with their psychological distress and moderated the relation between the experience of stigmatization and body image. Discussion: Weight‐based stigmatization is a common experience for obese individuals seeking weight loss treatment and appears to contribute to poor mental health adjustment. The negative effects of these experiences are particularly damaging for those who hold strong antifat beliefs. 相似文献
3.
Structural analysis of stigma development in sunflower highlights the secretory role of papillae due to its semi-dry nature. Production of lipid-rich secretions is initiated at the staminate stage of the flowers in stigma development and increases at the receptive stage, coinciding with an extensive development of elaioplasts and endoplasmic reticulum network in the basal region of the papillae. Transfer cells, earlier identified only in the wet type of stigma, are also present in the transmitting tissue of the sunflower stigma. Attainment of physiological maturity by the stigmatic tissue, accompanying development from bud to pistillate stage, appears to affect the initial steps of pollen–stigma interaction. The nature of self-incompatibility in Helianthus has also been investigated in relation with pollen adhesion, hydration and germination. Pollen adhesion to the stigma is a rapid process in sunflower and stigma papillae exhibit greater affinity for pollen during cross pollination as compared to self-pollination. Components of the pollen coat and the pellicle on the surface of stigmatic papillae are critical for the initial phase of pollen–stigma interaction (adhesion and hydration). The lipidic components of pollen coat and the proteinaceous and lipidic components from the surface of the papillae coalesce during adhesion, leading to the movement of water from stigma to the pollen, thereby causing pollen hydration and its subsequent germination. Pollen germination (both in self-and cross-pollen) on the stigma surface and the growth of the pollen tube characterize the flexibility of self-incompatibility in sunflower. Compatible pollen grains germinate and the pollen tube penetrates the stigma surface to enter the nutrient-rich transmitting tissue. The pollen tube from incompatible pollen germination, however, fails to penetrate the stigmatic tissue and it grows parallel to the papillae. Present findings provide new insights into structural and functional relationships during stigma development and pollen–stigma interaction. 相似文献
4.
Background and Aims
The coastal plain of Israel hosts the last few remaining populations of the endemic Iris atropurpurea (Iridaceae), a Red List species of high conservation priority. The flowers offer no nectar reward. Here the role of night-sheltering male solitary bees, honey-bees and female solitary bees as pollinators of I. atropurpurea is documented.Methods
Breeding system, floral longevity, stigma receptivity, visitation rates, pollen loads, pollen deposition and removal and fruit- and seed-set were investigated.Key Results
The main wild pollinators of this plant are male eucerine bees, and to a lesser extent, but with the potential to transfer pollen, female solitary bees. Honey-bees were found to be frequent diurnal visitors; they removed large quantities of pollen and were as effective as male sheltering bees at pollinating this species. The low density of pollen carried by male solitary bees was attributed to grooming activities, pollen displacement when bees aggregated together in flowers and pollen depletion by honey-bees. In the population free of honey-bee hives, male bees carried significantly more pollen grains on their bodies. Results from pollen analysis and pollen deposited on stigmas suggest that inadequate pollination may be an important factor limiting fruit-set. In the presence of honey-bees, eucerine bees were low removal–low deposition pollinators, whereas honey-bees were high removal–low deposition pollinators, because they removed large amounts into corbiculae and deposited relatively little onto receptive stigmas.Conclusions
Even though overall, both bee taxa were equally effective pollinators, we suggest that honey-bees have the potential to reduce the amount of pollen available for plant reproduction, and to reduce the amount of resources available to solitary bee communities. The results of this study have potential implications for the conservation of this highly endangered plant species if hives are permitted inside reserves, where the bulk of Oncocyclus iris species are protected. 相似文献5.
以授粉后具花闭合特性的紫茉莉为研究材料,通过在不同天气状况下作去花冠和存留花冠处理,观察花冠对花粉活力、柱头可授性及结实率等繁殖特性的影响。结果表明:紫茉莉自然存留花冠比去花冠的花粉活力、柱头可授性、柱头上的花粉数及柱头上花粉萌发率各指标达最高值的时间重叠性更强,并以阴天存留花冠的最强。存留花冠通过这种时间的重叠性来保证花粉在柱头上的萌发,产生了有利的繁殖适合度。越晚去花冠结实率越高,结实率呈现花闭合自然存留花冠>花冠闭合期去花冠>散粉初期去花冠>花冠展开期去花冠的规律。因此,花冠对紫茉莉繁殖适合度具有利影响。紫茉莉花冠的存留提高了繁殖适合度,增强了对环境的适应能力。 相似文献
6.
John B. Pryor Glenn D. Reeder Eric D. Wesselmann Kipling D. Williams James H. Wirth 《The Yale journal of biology and medicine》2013,86(2):189-201
This research explored the roles of social influence and stigma-related attitudes
in how people behaved toward an overweight female in an interactive computer
game. Photographs were used to manipulate whether one of the players in the game
was overweight or average weight. We found that both explicit and implicit
anti-fat attitudes influenced interactions with an overweight player, but only
when other players ostracized the overweight player, not when they included her.
Under conditions of ostracism, explicit attitudes were better predictors of more
controllable behaviors, while implicit attitudes were better predictors of more
automatic behaviors. 相似文献
7.
8.
Flowering phenology and flowering dynamics of female and male inflorescences of Salix viminalis Linn. in Beijing were observed in 2015 and 2016, and changes in pollen activity and stigma receptivity were also investigated. The results show that early flowering stage of S. viminalis in Beijing is happened in early?March, flowering period is 11-18 d, and flowering pattern is the first opening type of male flower. Flowering period of single inflorescence in male and female plants is 10-15 d and 8-10 d, respectively, which can be divided into five stages:emerging color stage, initial flowering stage, half flowering stage, full flowering stage and withered stage. Flowering date of male plant is earlier about 3-4 d than that of female plant. However, the difference of full flowering stage between male and female plants is only 1 d. Pollen germination rate and stigma receptivity show a trend of firstly increasing then decreasing during blossom process. Pollen germination rate reaches the highest of 72% at full flowering stage, and stigma receptivity is more than 90% at half and full flowering stages. Therefore, it is suggested that pollen collection and pollination in mid?March can improve success rate of cross breeding of S. viminalis. 相似文献
9.
Influence of pollen limitation and inbreeding depression in the maintenance of incomplete dichogamy in Salvia elegans 下载免费PDF全文
The widespread presence of incomplete dichogamy (i.e., partial separation in time between male and female phases) in flowering plants is a long‐standing question in floral evolution. In this study, we proposed four scenarios in which depending on the particular combination of pollen limitation and inbreeding depression, the presence of complete dichogamy, incomplete dichogamy, or adichogamy may be favored. Moreover, we evaluated the role of pollen limitation and inbreeding depression in a natural population of Salvia elegans to test the validity of our predicted scenarios. Our results indicate that S. elegans is partially protandrous as pollen viability and stigma receptivity overlap in the last days of life of the flower. Furthermore, through pollination treatments, we found no evidence of pollen limitation or inbreeding depression in any of the evaluated fitness components. As expected by one of the proposed scenarios, incomplete dichogamy seems to be favored in plants with absence of inbreeding depression and pollen limitation as a way to diminish interference between male and female functions. 相似文献
10.
Relationship of stigma behaviors and breeding system in three Mazus (Phrymaceae) species with bilobed stigma 下载免费PDF全文
Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self-spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self-pollen.Mazus stachydifolius was self-incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing. 相似文献