826 resultados para foraging habits
Resumo:
The studies presented in this thesis were carried out because of a lack of previous research with respect to (a) the habits and attitudes towards retinoscopy and (b) the relative accuracy of dedicated retinoscopes compared to combined types in which changing the bulb allows use in spot or streak mode. An online British survey received responses from 298 optometrists. Decision tree analyses revealed that optometrists working in multiple practices tended to rely less on retinoscopy than those in the independent sector. Only half of the respondents used dynamic retinoscopy. The majority, however, agreed that retinoscopy was an important test. The University attended also influenced the type of retinoscope used and the use of autorefractors. Combined retinoscopes were used most by the more recently qualified optometrists and few agreed that combined retinoscopes were less accurate. A trial indicated that combined and dedicated retinoscopes were equally accurate. Here, 4 optometrists (2 using spot and 2 using streak retinoscopes) tested one eye of 6 patients using combined and dedicated retinoscopes. This trial also demonstrated the utility of the relatively unknown ’15 degrees of freedom’ rule that exploits replication in factorial ANOVA designs to achieve sufficient statistical power when recruitment is limited. An opportunistic international survey explored the use of retinoscopy by 468 practitioners (134 ophthalmologists, 334 optometrists) attending contact related courses. Decision tree analyses found (a) no differences in the habits of optometrists and ophthalmologists, (b) differences in the reliance on retinoscopy and use of dynamic techniques across the participating countries and (c) some evidence that younger practitioners were using static and dynamic retinoscopy least often. In conclusion, this study has revealed infrequent use of static and dynamic retinoscopy by some optometrists, which may be the only means of determining refractive error and evaluating accommodation in patients with communication difficulties.
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In recent treatments of habitual social behaviour, habits are conceptualized as a form of goal-directed automatic behaviour that are mentally represented as goal-action links. Three experiments tested this conceptualization in the context of students' drinking (alcohol consumption)habits. Participants were randomly assigned to conditions where either a goal related to drinking behaviour (socializing) was activated, or an unrelated goal was activated. In addition, participants' drinking habits were measured. The dependent variable in Experiments 1 and 2 was readiness to drink, operationalized by speed of responding to the action concept 'drinking' in a verb verification task. Experiment 3 used the uptake of a voucher to measure drinking behaviour. Findings supported the view that when habits are established, simply activating a goal related to the focal behaviour automatically elicits that behaviour. These findings are consistent with a goal-dependent conception of habit. Possibilities for interventions designed to attenuate undesirable habitual behaviours are considered.
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When designing a practical swarm robotics system, self-organized task allocation is key to make best use of resources. Current research in this area focuses on task allocation which is either distributed (tasks must be performed at different locations) or sequential (tasks are complex and must be split into simpler sub-tasks and processed in order). In practice, however, swarms will need to deal with tasks which are both distributed and sequential. In this paper, a classic foraging problem is extended to incorporate both distributed and sequential tasks. The problem is analysed theoretically, absolute limits on performance are derived, and a set of conditions for a successful algorithm are established. It is shown empirically that an algorithm which meets these conditions, by causing emergent cooperation between robots can achieve consistently high performance under a wide range of settings without the need for communication. © 2013 IEEE.
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A hálózatos iparágakban, ahogy a postai szolgáltatásoknál is, a forgalomban lévő készpénz nagyméretű működőtőkét jelenthet. A Magyar Posta a levél- és csomagkézbesítésen kívül jelentős készpénzforgalmat bonyolít le: nyugdíjakat, segélyeket és készpénz-átutalási megbízásokat továbbít. A forgalom napi ingadozása a vállalat likvideszköz-igényét jelentősen meghatározza. A posta esetében a postahivatalok készpénzgazdálkodása jól működő hüvelykujjszabályokon keresztül történik, ezek a szabályok döntési teret hagynak a hálózat heterogén egyedi szereplőinek. Az egyedi készletezési viselkedést a vállalati működőtőke meghatározásakor figyelembe kell venni. A tanulmány az egyedi készletezési szokások modellezésére új módszertant ajánl, majd a viselkedésmintákat csoportosítva a pénzkészletezésnek, a vállalati működőtőke szintjének és a vállalati likviditási pozíciónak a kapcsolatát elemzi. / === / The cash in circulation within network industries such as post-office services can repre-sent a sizeable quantity of operating capital. The Hungarian Post Office, besides han-dling mail, handles a significant amount of cash turnover, forwarding pensions, welfare benefits, and cash orders. Fluctuation in the daily volume of these is a strong factor in determining the company's liquidity requirements. The management of cash in post of-fices is governed by rules of thumb that operate well; the regulations leave decision-making scope for the diverse individual actors in the network. Attention has to be paid to individual cash holding when determining the corporate operating capital. The study suggests a new methodology for modelling the individual cash-holding habits, and goes on to group the behaviour patterns by analysing the connection between cash holding, level of corporate operating capital, and corporate liquidity position.
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A közelmúltban készült kutatásban a szerzők azt vizsgálták, hogy a kis- és középvállalkozásokban az elektronikus banki ügyintézéssel kapcsolatban milyen szokásaik, attitűdjeik és jövőképeik alakultak ki. A több mint ötszáz KKV-vezetővel készült interjú alapján elmondható, hogy a vállalkozás elektronikus ügyintézéssel kapcsolatos hozzáállása egyáltalán nem, vagy csak nagyon gyenge mértékben hozható összefüggésbe a cég objektív tulajdonságaival, például a létszámmal, az árbevétellel vagy a tevékenységi körrel. Egyértelműen látszik, hogy már az elektronikus banki ügyintézéssel kapcsolatos fogalmak értelmezése is problémát jelent a KKV-vezetők egy részénél. A tudásbeli hiányosságok pedig egyértelműen befolyásolják az e-banking attitűdöt és a használati szokásokat, pedig az elektronikus csatornákat használók elégedettsége minden vizsgált bank ügyfeleinek esetében 80% fölötti értékeket mutat. Így a legfontosabb kérdés az, hogy miként lehetne megértetni a „Szkeptikusok”-kal és a „Mérlegelők”-kel, hogy érdemes a „Haladók” klaszterébe tartozni. Az ügyfélelégedettség sikertényezői egyértelműen a biztonság, az időben és térben széles körű elérhetőség és az egyszerű használat. A válaszadók jövőképe szerint a banki szolgáltatások igénybevétele egyre inkább eltolódik majd az elektronikus csatornák irányába. Jelen cikkben a kutatás legfontosabb tanulságait mutatják be a szerzők. _________ The authors’ research was conducted to explore the ebanking attitudes, habits and vision of small and medium enterprises. By the interviews of more than 500 managers of SMEs, it is concluded that e-banking attitudes are not, or not significantly related to the objective characteristics of the enterprises, e.g. to the number of employment, the revenues or its activities. It became clear, that the interpretation of the specific e-banking terms means an important problem for some managers. The deficiencies of knowledge have direct effects on e-banking attitude and the use of electronic banking methods of the enterprises, although the value of the satisfaction level is above 80% among the customers of each examined banks. Thus, the main objective is to explain to the “Scepticals” and the “Considerers” the benefits of the “Progressives” cluster. The most important success factors of customer satisfaction are safety, availability in time and space and ease of use. According to the vision of the respondents, banking services will probably be shifted towards e-channels. In this study, the most important findings of our researches were summarized.
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Accidents are the leading cause of death among children. Compliance with safety measures have been shown to reduce morbidity and mortality in children. However, Hispanic parents and children have not been adequately studied in the literature in regard to trauma and safety habits utilized. In this exploratory-descriptive study, a convenience sample of 48 Hispanic parents were questioned about their child's activities. The purpose was to determine what safety equipment was used during these activities and how often they were used. Responses to an English/Spanish questionnaire were summarized by frequencies and percentages. Findings suggested that these Hispanic children were at risk for injury due to a low percentage of children wearing the necessary protective equipment. Therefore, education must stress consistent use of safety equipment if injuries are to be prevented. ^
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The purpose of this study was to demonstrate if the academic assistance program Supplemental Instruction (SI) facilitates the acquisition of effective study behaviors through strategies that transcend simple double-exposure to the course material. Its advocates claim it increases academic achievement using learner-centered knowledge and acquisition of effective study behaviors. SI sessions are specifically related to particular courses that students are taking. Sessions are facilitated by the SI leader who has taken the subject matter course in the past. Students review the content of the previous subject matter class using collaborative learning strategies coordinated by a SI leader. In addition, the SI leader models appropriate study behaviors in his or her interactions with the students. ^ An instructor at a large Florida community college who taught five classes of an Anatomy & Physiology I course (traditionally supported by SI) was identified. Two of the classes were randomly selected to participate in SI activities, and two classes were random chosen to participate in alternate, computer-based activities that dealt with the course content, but did not include work in developing students' study behaviors. These treatments were carried out over the course of an entire semester. Participation was mandatory. ^ Data were collected on two variables. Academic achievement in anatomy and physiology content was measured both pre- and post-treatment using an instructor developed examination. Student study behaviors were measured using pre- and post-treatment administration of the Study Behavior Inventory, a valid and reliable instrument that provides scores on three categories of study behaviors: (a) Academic self-efficacy, (b) Preparation for routine academic tasks, and (c) Preparation for long range academic tasks. Measures obtained at the end of the semester of treatment revealed no significant differences between the SI and alternative treatment groups in post-treatment achievement test score and the post-treatment scores on the three study behaviors categories when adjusted for pre-treatment scores. ^ These results suggest that the development of appropriate study behaviors requires more time than SI, as it is now implemented, can provide. In addition, results indicate that improved academic achievement may be attained through any number of means that include repeated exposure to course material. ^
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Worldwide declines in populations of large elasmobranchs and the potential cascading effects on marine ecosystems have garnered considerable attention. Far less appreciated are the potential ecological impacts of changes in abundances of small to medium bodied elasmobranchs mesopredators. Crucial to elucidating the role of these elasmobranchs is an understanding of their habitat use and foraging ecology in pristine conditions. I investigated the trophic interactions and factors driving spatiotemporal variation in abundances of elasmobranch mesopredators in the relatively pristine ecosystem of Shark Bay, Australia. First, I describe the species composition and seasonal habitat use patterns of elasmobranch mesopredator on the sandflats of Shark Bay. Juvenile batoids dominated this diverse community and were extremely abundant in nearshore microhabitats during the warm season. Stomach content analysis and stable isotopic analysis revealed that there is a large degree of dietary overlap between common batoid species. Crustaceans, which tend to be found in seagrass habitats, dominated diets. Despite isotopic differences between many species, overlap in isotopic niche space was high and there was some degree of individual specialization. I then, investigated the importance of abiotic (temperature and water depth) and biotic (prey and predator abundance) factors in shaping batoid habitat use. Batoids were most abundant and tended to rest in shallow nearshore waters when temperatures were high. This pattern coincides with periods of large shark abundance suggesting batoids were seeking refuge from predators rather than selecting optimal temperatures. Finally, I used acoustic telemetry to examine batoid residency and diel use of the sandflats. Individual batoids were present on the sandflats during both the warm and cold seasons and throughout the diel cycle, suggesting lower sandflat densities during the cold season were a result of habitat shifts rather than migration out of Shark Bay. Combined, habitat use and dietary results suggest that batoids have the potential to seasonally impact sandflat dynamics through their presence, although foraging may be limited on the sandflats. Interestingly, my results suggest that elasmobranch mesopredators in pristine ecosystems probably are not regulated by food supply and their habitat use patterns and perhaps ecosystem impacts may be influenced by their predators.
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Top predators can have large effects on community and population dynamics but we still know relatively little about their roles in ecosystems and which biotic and abiotic factors potentially affect their behavioral patterns. Understanding the roles played by top predators is a pressing issue because many top predator populations around the world are declining rapidly yet we do not fully understand what the consequences of their potential extirpation could be for ecosystem structure and function. In addition, individual behavioral specialization is commonplace across many taxa, but studies of its prevalence, causes, and consequences in top predator populations are lacking. In this dissertation I investigated the movement, feeding patterns, and drivers and implications of individual specialization in an American alligator (Alligator mississippiensis ) population inhabiting a dynamic subtropical estuary. I found that alligator movement and feeding behaviors in this population were largely regulated by a combination of biotic and abiotic factors that varied seasonally. I also found that the population consisted of individuals that displayed an extremely wide range of movement and feeding behaviors, indicating that individual specialization is potentially an important determinant of the varied roles of alligators in ecosystems. Ultimately, I found that assuming top predator populations consist of individuals that all behave in similar ways in terms of their feeding, movements, and potential roles in ecosystems is likely incorrect. As climate change and ecosystem restoration and conservation activities continue to affect top predator populations worldwide, individuals will likely respond in different and possibly unexpected ways.
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The coastal wetlands of northeastern Florida Bay are seasonally-inundated dwarf mangrove habitat and serve as a primary foraging ground for wading birds nesting in Florida Bay. A common paradigm in pulse-inundated wetlands is that prey base fishes increase in abundance while the wetland is flooded and then become highly concentrated in deeper water refuges as water levels recede, becoming highly available to wading birds whose nesting success depends on these concentrations. Although widely accepted, the relationship between water levels, prey availability and nesting success has rarely been quantified. I examine this paradigm using Roseate Spoonbills that nest on the islands in northeastern Florida Bay and forage on the mainland. Spoonbill nesting success and water levels on their foraging grounds have been monitored since 1987 and prey base fishes have been systematically sampled at as many as 10 known spoonbill foraging sites since 1990. Results demonstrated that the relationship between water level and prey abundance was not linear but rather there is likely a threshold, or series of thresholds, in water level that result in concentrated prey. Furthermore, the study indicates that spoonbills require water level-induced prey concentrations in order to have enough food available to successfully raise young.
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BACKGROUND: The Pro Children Eating Habits Questionnaire has been evaluated as a valid and reliable tool in Europe to measure determinants of fruit and vegetable intake for children; however, it has not been validation for United States populations. The purpose of this study was to (1) assess the reliability and discrimination validity of fruit and vegetable correlates for the Pro Children Eating Habits Questionnaire; (2) investigate the predictive validity of determinants of fruit and vegetable consumption for multi-ethnic elementary school children; and, (3) to assess the association of social determinants with fruit and vegetable consumption. METHODS: One hundred and thirty elementary school students from the 3rd and 5th grades completed this cross-sectional study. RESULTS: Fruit and vegetable determinants, had satisfactory internal consistencies. No differences were found between the test and the retest for the individual questions with the exception of the question for mean perceived vegetable intake. The discriminatory validity indicated the questionnaire could show differences across grade and gender levels for barriers of fruit and vegetables but not for other factors. Grade together with gender explained barriers to eating fruit and vegetables. Greater availability of fruit in the home and school was associated with higher frequency of consumption. CONCLUSIONS: The results of this study indicate the Pro-Children Eating Habits Questionnaire may be a reliable and valid tool for assessing fruit and vegetable consumption of children in the United States.
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Dr. Miguel A. De La Torre is a Professor of Social Ethics at Illif School of Theology. His lecture is on the interplay between American eating habits and its contribution to oppressive structures throughout Latin America.
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Through bioturbation, the macrofauna mediate chemical, physical and biological processes in marine benthic ecosystems. Because of the importance of bioturbation as ecosystem mediator, various studies have been conducted on bioturbation intensity and depth, and the relation of bioturbation processes to environmental condition and ecosystem state. This thesis builds on those previous studies, using a standard field and analytical protocol and by expanding the geographical scale to three climatic regions along Canada’s East Coast and Arctic margins, the Arctic Archipelago, the coastal Subarctic (Labrador Fjords), and the temperate continental climate zone (Gulf of Maine and adjacent Scotian shelf/slope). This Ph.D. study provides a comprehensive assessment of environmental influences on bioturbation along gradients in latitude and ocean depth. Bioturbation intensity, mixing depth, and bioturbation structures were studied in relation to the quantity and quality of potential food sources (organic matter) and substrate characteristics to gain an understanding of the environmental controls on bioturbation in these regions. The three main research chapters of this thesis are divided based on the contrasting climatic and geographical regions studied. The analytical approach included seabed sampling with a boxcorer, describing the sedimentary fabric and bioturbation structures by X-radiography, estimating bioturbation intensity and depth applying a biodiffusion model to particle tracer profiles of ²¹⁰Pbₓs, ²²⁸Thₓs, ²³⁴Thₓs, and chlorophyll-a, and analyzing benthic organic matter and substrate characteristics. Strong regional and cross-climatic relations of bioturbation processes with combinations of environmental factors were observed. In particular, bioturbation depth and the vertical extent of bioturbation structures responded to the environmental patterns observed and, therefore, represented potentially applicable predictors of environmental conditions and ecosystem state. The results of this Ph.D. study may be further extended to other geographical regions with similar environmental characteristics to predict the effects of benthic habitat alterations through environmental stresses on a global scale. Integrated with biological data produced by fellow CHONe scientists the presented data may provide valuable information about functional roles of macrofaunal species and community traits in marine benthic ecosystems along Canada’s extensive East Coast and Arctic margins.
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Background: To determine the portion sizes of traditional and non-traditional foods being consumed by Inuit adults in three remote communities in Nunavut, Canada. Methods. A cross-sectional study was carried out between June and October, 2008. Trained field workers collected dietary data using a culturally appropriate, validated quantitative food frequency questionnaire (QFFQ) developed specifically for the study population. Results: Caribou, muktuk (whale blubber and skin) and Arctic char (salmon family), were the most commonly consumed traditional foods; mean portion sizes for traditional foods ranged from 10 g for fermented seal fat to 424 g for fried caribou. Fried bannock and white bread were consumed by >85% of participants; mean portion sizes for these foods were 189 g and 70 g, respectively. Sugar-sweetened beverages and energy-dense, nutrient-poor foods were also widely consumed. Mean portion sizes for regular pop and sweetened juices with added sugar were 663 g and 572 g, respectively. Mean portion sizes for potato chips, pilot biscuits, cakes, chocolate and cookies were 59 g, 59 g, 106 g, 59 g, and 46 g, respectively. Conclusions: The present study provides further evidence of the nutrition transition that is occurring among Inuit in the Canadian Arctic. It also highlights a number of foods and beverages that could be targeted in future nutritional intervention programs aimed at obesity and diet-related chronic disease prevention in these and other Inuit communities.
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This article analyses the influence that different criticism stages of proceedings exert in the habits of theatre attendance. The study is based on the survey carried out specifically for this research in which 210 people, who attended a theatrical representation, were interviewed in three different theatres in the city of Valencia. The study has revealed the mouth to mouth importance in the decision of attending the theatre and its stronger influence on the audiences who less frequently go to theatrical representations. The results obtained have also made clear the existence of a narrow relation between the advice effect of the theatre critics and the patterns of attendance to the theatre, just like its bigger influence between theatres with commercial orientation and those which are addressed to the broad audiences.