985 resultados para Revealed preference


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Introduction: Several preference studies comparing a short-acting with a longer-acting phosphodiesterase type 5 inhibitor have been conducted in men. Most men in those studies preferred tadalafil rather than sildenafil, and recent post hoc analysis of one study described several factors associated with men’s treatment preference. No prospective studies have investigated the woman partners’ preferences.

Aim: To investigate the treatment preference of women who were partners of men using oral medications for erectile dysfunction (ED) in a single-center open-label crossover study.

Methods: One hundred heterosexual couples in stable relationships, with male partners having ED based on the erectile function subscale of the International Index of Erectile Function, were randomly assigned to receive sildenafil or  tadalafil for a 12-week phase, followed by another 12-week period using the alternate drug. Male and female participants completed sexual event diaries during both study phases, and the female participants were interviewed at  baseline, midpoint, and end of study.

Main Outcome Measures
: Primary outcome data were the women’s final  interviews during which they were asked which drug they preferred and their reasons for that preference.

Results: A total of 79.2% of the women preferred their partners’ use of tadalafil, while 15.6% preferred sildenafil. Preference was not affected by age or treatment order randomization. Women preferring tadalafil reported feeling more relaxed, experiencing less pressure, and enjoying a more natural or spontaneous sexual experience as reasons for their choice. Mean number of tablets used, events recorded, events per week, and days between events were not significantly different during each study phase.

Conclusion: Women’s preferences were similar to men when using these two drugs. While the women’s reasons for preferring tadalafil emphasized relaxed, satisfying, longer-lasting sexual experiences, those preferring sildenafil focused on satisfaction and drug effectiveness for their partner.

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The study reported in this paper examined a group of Australian taxpayers who have expressed a preference for a creative and aggressive tax agent. The study attempted to understand how high-risk taxpayers and high-risk practitioners form their partnerships by examining aggressive taxpayers' attitudes and perceptions of the Australian tax system. Data were taken from 2040 Australian taxpayers who had responded to a national survey on tax issues. Results from a series of independent sample t-tests revealed that there are a number of important differences between 'aggressive' and 'non-aggressive' taxpayers. Finally, a logistic regression analysis was used to determine which variables most effectively differentiated aggressive taxpayers from non-aggressive taxpayers. The findings are discussed in a regulatory context and possible solutions for how tax authorities might deal with this high-risk group of taxpayer are suggested.

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Despite major differences between human and avian colour vision, previous studies of cuckoo egg mimicry have used human colour vision (or standards based thereon) to assess colour matching. Using ultraviolet-visible reflectance spectrophotometry (300-700 nm), we measured museum collections of eggs of the red-chested cuckoo and its hosts. The first three principal components explained more than 99% of the variance in spectra, and measures of cuckoo-host egg similarity derived from these transformations were compared with measures of cuckoo-host egg similarity estimated by human observers unaware of the hypotheses we were testing. Monte Carlo methods were used to simulate laying of cuckoo eggs at random in nests. Results showed that host and cuckoo eggs were very highly matched for an ultraviolet versus greenness component, which was not detected by humans. Furthermore, whereas cuckoo and host were dissimilar in achromatic brightness, humans did not detect this difference. Our study thus reveals aspects of cuckoo-host egg colour matching which have hitherto not been described. These results suggest subtleties and complexities in the evolution of host-cuckoo egg mimicry that were not previously suspected. Our results also have the potential to explain the longstanding paradox that some host species accept cuckoo eggs that are non-mimetic to the human eye.

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Zebra finches have previously been found to have preferences for particular colours of both natural and artificial traits among opposite sex conspecifics. For example, in some studies female zebra finches preferred males wearing red leg bands to orange-banded and unbanded birds and rejected light green-banded males. In other studies, females also preferred males with red beaks to orange-beaked males. However, several authors have failed to replicate these results. We show that females may fail to show a colour preference because of the absence or removal of ultraviolet light under experimental conditions. In mate-choice trials, females observing males through filters that transmitted ultraviolet preferred red-banded males but where females viewed males through ultraviolet-blocking filters, no such preference was observed. Further investigation revealed that the lack of a colour preference when ultraviolet was absent was probably due to the change in overall appearance of the bird, rather than the change in appearance of the rings themselves. This work highlights the importance of proper consideration of the sensory capabilities of animals in experimental design, particularly with regard to the role of ultraviolet light in avian colour perception. (C) 1997 The Association for the Study of Animal Behaviour.

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A male bowerbird visual signal includes his own plumage, a structure he  constructs out of plant material and coloured objects (ornaments) he places on or near the structure to make up the bower. Plumage and bower together are used to attract females for mating. Ornaments are known to contrast with plumage, bower structure and visual backgrounds in seven Australian bowerbird species (Endler et al. 2005, Evolution, 50, 1795-1818). We estimated the colour preferences in a wild population of great bowerbirds using artificially coloured objects widely spaced in bird colour space. We found that these birds prefer colours that contrast with their own plumage, the bower structure and the visual backgrounds adjacent to the bower, and that they have very strong dislikes for colours that are similar to their own plumage and to the visual backgrounds. The range of disliked colour hues was much narrower than the range of preferred hues, suggesting that the word 'preference' may be misleading. Preferences for colour are inherently multidimensional and should be studied in the context of their function.

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This thesis is involved with changes that have occurred to small mammal populations following a major disturbance in the Anglesea region as a result of the 1983 Ash Wednesday fires. Fire, with its effects on spatial and temporal heterogeneity, was found to be an important factor in the maintenance of vegetation and small mammal community structure and diversity in the region. Successional changes in vegetation and small mammal communities were described by multivariate analyses, using data collected annually from 22 study sites. The use of factor analysis techniques, in reducing the annual capture data content, enabled long-term changes in the structure of mammal communities to be interpreted. The small mammal communities in the coastal heath and forest vegetation in the Anglesea region show evidence of a general resilience, (the degree and speed of recovery), to disturbance. Two phases of successional response to fire by mammal species have been proposed; a ‘re-establishment’ phase which occurs in the initial 5-6 years post-fire and is accompanied by rapid increase in species’ abundance, and a subsequent ‘maintenance’ phase accompanied by relatively minor changes in abundance. Habitat Suitability Indices were produced relating to these phases. Vertical density measures of understorey shrubs and herb layers showed significant relationships with small mammal species abundance at the study sites. Long term studies following major disturbances are needed to distinguish between short term recovery of plant and animal species and long term changes in these species. Studies extending over a number of years enable a better directional view of changes in small mammal communities than can be determined from . observations made over a short period. As a part of the investigation into temporal change, it was proposed to undertake trial reintroductions of the Swamp antechinus, Ant echinus minimus, a marsupial dasyurid species which was trapped in the area prior to the 1983 fire, but rarely subsequently. Other more commonly observed native small mammal species (e.g. Rattus fuscipes,R. lutreolus, Antechinus stuartii, Sminthopsis leucopus) had re-invaded the proposed reintroduction site after this fire. Failure of A. minimus to re-establish may have been due to spatial separation of the pre-fire populations coupled with the extensive area burnt in 1983, A source population of the species was located about 100km to the west and habitat utilization and interspecific and niche relationships between the species making the small mammal community explored. Discriminant analysis revealed some spatial separation of species within a habitat based on structural vegetation factors rather than floristic factors. Temporal separation of species was observed, asA. minimus were more active than Rattus species during daylight periods. There was evidence of micro-habitat selection by species, and structural vegetation factors were most commonly identified in statistical analyses as contributing towards selection by small mammal species. Following a theoretical modelling study three reintroduction trials were carried out near Anglesea during 1992-94. Individuals were subsequently radio tracked, and habitat relationships between the species in the small mammal community investigated. Although successful breeding of A, minimus occurred during the latter two trials, the subsequent fate of offspring was not determined. Invasive techniques required to adequately monitor young animals were considered potentially too damaging. Telemetry studies indicated a preference of A. minimus for short, wet heath vegetation. Structural vegetation factors were identified as being significant in discriminating between capture locations of species. Small scale and inexpensive trial reintroductions have yielded valuable additional data on this species and may be viewed as a useful tool in the conservation of other small native mammals.

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There is sparse information on how treatments for erectile dysfunction (ED) affects couples. This study investigated the effects of ED treatments on 100 heterosexual couples' sexual functioning and whether function achieved using a short-acting versus a long-acting ED medication differed significantly. Couples were randomized to use tadalafil or sildenafil for each of two 12-week study phases; they completed questionnaires (International Index of Sexual Function and Female Sexual Function Index) and kept sexual event diaries. All participants experienced significant improvements over baseline sexual functioning, while the men used short- or long-acting ED medications with no significant differences related to the duration of drug action recorded for either the men or women. Despite this lack of difference in efficacy there was a strong preference by women (79%) and their partners (16%) for the longer-acting medication. The reasons for this warrant further investigation. Understanding the effects on couples of the use of ED medications is a necessary aspect of ensuring ongoing sexual satisfaction in couples treated for ED.

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Porous titanium (Ti) and titanium alloys are promising scaffold biomaterials for bone tissue engineering, because they have the potential to provide new bone tissue ingrowth abilities and low elastic modulus to match that of
natural bone. In the present study, a new highly porous Ti6Ta4Sn alloy scaffold with the addition of biocompatible alloying elements (tantalum (Ta) and tin (Sn)) was prepared using a space-holder sintering method. The
strength of the Ti6Ta4Sn scaffold with a porosity of 75% was found to be significantly higher than that of a pure Ti scaffold with the same porosity. The elastic modulus of the porous alloy can be customized to match that of
human bone by adjusting its porosity. In addition, the porous Ti6Ta4Sn alloy exhibited an interconnected porous structure, which enabled the ingrowth of new bone tissues. Cell culture results revealed that human SaOS2
osteoblast-like cells grew and spread well on the surfaces of the solid alloy, and throughout the porous scaffold. The surface roughness of the alloy showed a significant effect on the cell behavior, and the optimum surface
roughness range for the adhesion of the SaOS2 cell on the alloy was 0.15 to 0.35 mm. The present study illustrated the feasibility of using the porous Ti6Ta4Sn alloy scaffold as an orthopedic implant material with a special
emphasis on its excellent biomechanical properties and in vitro biocompatibility with a high preference by osteoblast-like cells.

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Basic research has revealed that the chemical sensory world of children is different from that of adults, as evidenced by their heightened preferences for sweet and salty tastes. However, little is known about the ontogeny of sour taste preferences, despite the growing market of extreme sour candies. The present study investigated whether the level of sourness most preferred in a food matrix and the ability to discriminate differences in sour intensity differed between 5- to 9-year-old children and their mothers, by using a rank-by-elimination procedure embedded in the context of a game. Mothers also completed a variety of questionnaires and children were asked several questions to assess whether children's temperament and food preferences and habits related to sour preferences. The results indicated that, although every mother and all but two of the children (92%) were able to rank the gelatins from most to least sour, more than one-third (35%) of the children, but virtually none of the adults, preferred the high levels of sour taste (0.25 M citric acid) in gelatin. Those children who preferred the extreme sour tastes were significantly less food neophobic (P < 0.05) and tended to experience a greater variety of fruits when compared with the remaining children (P = 0.11). Moreover, the children's preference for sour tastes generalized to other foods, such as candies and lemons, as reported by both children and mothers. These findings are the first experimental evidence to demonstrate that sour taste preferences are heightened during childhood and that such preferences are related to children's food habits and preferences. Further research is needed to unfold the relationship between the level of sour taste preferred and the actual consumption of sour-tasting foods and flavors in children.

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Previous research has suggested that some children have a preference for sour tastes. The origin of this preference remains unclear. We investigated whether preference for sour tastes is related to a difference in rated sour intensity due to physiological properties of saliva, or to an overall preference for intense and new stimuli. Eighty-nine children 7–12 years old carried out a rank-order procedure for preference and category scale for perceived intensity for four gelatins (i.e. 0.0 M, 0.02 M, 0.08 M, 0.25 M added citric acid) and four yellow cards that differed in brightness. In addition, we measured their willingness to try a novel candy and their flow and buffering capacity of their saliva. Fifty-eight percent of the children tested preferred one of the two most sour gelatins. These children had a higher preference for the brightest color (P < 0.05) and were more likely to try the candy with the unknown flavor (P < 0.001) than children who did not prefer the most sour gelatins. Preference for sour taste was not related with differences in rated sour intensity, however those who preferred sour taste had a higher salivary flow (P < 0.05). These findings show that a substantial proportion of young children have a preference for extreme sour taste. This appears to be related to the willingness to try unknown foods and preference for intense visual stimuli. Further research is needed to investigate how these findings can be implemented in the promotion of sour-tasting food such as fruit.

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In this thesis, the author designed three sets of preference based ranking algorithms for information retrieval and provided the corresponsive applications for the algorithms. The main goal is to retrieve recommended, high similar and valuable ranking results to users.

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This paper reports an empirical study of the factors affecting burden sharing among OECD's 22 DAC members in 'bankrolling' the multilateral aid agencies. Annual data over 1970–2000, pooled across the donor countries, form the basis for the empirical estimation of each donor's share in the ODA aid receipts for each multilateral agency. Our findings suggest the existence of reverse exploitation, i.e., the financial burden of the agencies is disproportionally carried by the smaller donors. The study also finds that factors such as inherent donor generosity, donor concern for domestic egalitarianism, and the extent to which donors are pro-poor in their bilateral aid policies have an impact on their readiness to support multilateral agencies financially. Size of the donor government and its budgetary balance positively influence burden sharing of contributions to other multilateral agencies. But neither the phase of economic cycle nor the rate of economic growth affects the burden-sharing responsibility of donors. It was also observed that contributions by EU members to the EC do not appear to crowd-out their contributions to other multilateral aid agencies and that right-wing donor governments are generally more parsimonious with regard to financial assistance to multilateral aid agencies. The preferred alternative, particularly among EU member countries, appears to be the EC.

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Objective
Health literacy refers to an individual's ability to seek, understand, and use health information. A range of indices exist that purport to measure health literacy across individuals and populations. This study aimed to review the development and content of existing indices and to critically appraise their properties.

Study Design and Setting
Using standardized search terms, published generic health literacy indices (1990–2008) were identified. Using a methodological framework, each was evaluated for purpose, validity (face, content, construct), reliability, responsiveness, feasibility, and generalizability.

Results
Nineteen instruments were evaluated. Three measurement approaches were identified: direct testing of individual abilities, self-report of abilities, and population-based proxy measures. Composition of underlying constructs and content varied widely across instruments, and none appeared to fully measure a person's ability to seek, understand, and use health information. The content was focused primarily on reading comprehension and numeracy; scoring categories were poorly defined and may not be mutually exclusive, and few indices had been assessed for reliability.

Conclusion

Health literacy is not consistently measured, making it difficult to interpret and compare health literacy at individual and population levels. Empirical evidence demonstrating validity and reliability of existing indices is required, and more comprehensive health literacy instruments need to be developed.