Much of what we know about temperature-dependent sex determination (TSD) in reptiles stems from constant temperature incubation studies in the laboratory. In recent years, as TSD studies moved into the field it became evident that TSD was much more complex than previously thought. The present study attempted to reveal the complexity of TSD, as it relates to other features of the species' biology and physical characteristics tractable only in the field, such as fluctuations in incubation temperature and reproductive life history. To this end I studied the ecology of the turtle Carettochelys insculpta, a TSD species inhabiting the wet-dry tropics of northern Australia from 1996 to 1998. I tested hypotheses associated with movements, activity, behaviour, reproduction, nest site choice, nest temperatures, embryonic survival, embryonic aestivation, hatch-ling sex ratios, and emergence in the species. Each of these was also considered in the context of the influence of the wet-dry tropics. Compared to other turtles inhabiting lotic habitats, C. insculpta occupied considerably larger home ranges, covering up to 10 km of river. Of previously published factors influencing home range size, low productivity of the (micro) habitat may best explain the extensive home ranges in C. insculpta. Patchiness and low nutrient value of the chief food (aquatic vegetation) of C. insculpta may force turtles to cover large expanses of river to acquire sufficient energy for growth and reproduction. Females were more active, moved farther, and occupied larger home ranges than males. Home ranges of females comprised 1-4 activity centres, many of which were associated with thermal springs. I suggest that females may exhibit increased activity and movements relative to males because of sexual inequality in parental investment, where food is particularly limiting (e.g., in species with biennial reproduction). Biennial reproduction in the population allowed the examination of the influence of reproductive condition on home range size, movements, and activity. Reproductive condition did not influence home range or activity, but gravid turtles moved father between successive sightings than non-gravid females. Individual data corroborate these findings, with females moving farther between successive sightings while gravid compared to while spent. Contrary to previous reports, turtles did not appear to move into estuarine areas or lowland flood plains during the wet season, but moved into the riparian forest and possibly into wetlands adjacent to the main channel in the vicinity of their dry season home ranges. During the study I documented the turtles' use of small, localized thermal springs discharging from the river bottom. Dataloggers attached to the carapace to monitor ambient water temperatures recorded the frequency and duration of thermal spring use by individuals. Turtles used the thermal springs frequently during the winter (4-6 months) when river temperatures were lower than that of the thermal springs (8 = 29 � 0.52� C). Turtles often utilized thermal springs for several consecutive hours, leaving the springs only to surface for air. Thermal springs may be derived from ground water (which maintains a temperature equivalent to the annual mean air temperature), rather than from a specific geothermal heat source. Nine of 19 radio-telemetered adult females were seen to use thermal springs, of which seven were gravid and two non-gravid. Thus, gravid turtles may seek thermal springs more than non-gravid turtles. Frequency, duration, and timing of usage collectively suggest active thermoregulation as the primary function of thermal spring use. Utilization of thermal springs probably permits turtles to be more active in cooler months, which may enhance growth rates and accumulation of energy for reproduction. Onset of nesting along river stretches with thermal springs preceded nesting in a stretch not known to have thermal springs by 24 days. Thus, I speculate that by warming themselves on thermal springs in the months prior to nesting, turtles may have accelerated follicular development and nested earlier. Female C. insculpta matured at ca. 6 kg body mass (38.0 cm carapace length, 30.5 cm plastron length). Turtles produced egg sizes and clutch sizes similar to that of other turtle species of similar size. Turtles reproduced every second year, but produced two clutches in each breeding year, ca. 40 days apart. Thus, it appeared that females were energy limited, possibly due to the low available energy content of the dry season diet (aquatic vegetation). Life history theory predicts that if some costly behaviour is associated with reproduction, skipping years could reduce that cost and allow savings to be directed into future reproduction. The present study revealed no obvious accessory behaviour in the population. Within years, clutch mass did not differ between early (first) and late (second) clutches. However, earlier clutches tended to have more and smaller eggs per clutch but than later clutches, a new finding for turtles that has been demonstrated in lizards and other animals. Because the study spanned both years with 'big' and 'small' wet seasons, I was able to examine how the magnitude of the wet season influenced reproductive characteristics. Following big wet seasons turtles produced larger, heavier, and more eggs per clutch than they did after small wet seasons. Relationships among body size, egg size, and clutch size were evident after two big wet seasons but not apparent after two small wet seasons. Collectively, annual variation in reproductive characteristics and current life history theory suggest that a big wet season is a plentiful time for the turtles. I investigated beach selection of nesting pig-nosed turtles (Carettochelys insculpta) along a 63 km stretch of river in 1997 and 1998. I used three classes of beaches to examine beach choice: beaches with nests, beaches with only crawls, andbeaches without nests or crawls. Across these beach types I compared aspect, solar exposure, temperature, substrate moisture, height, water depth at approach, and the height of cohesive sand. I located 82 nesting beaches with 221 nests, and identified 171 potential nesting beaches based on previously published criteria. Beaches with nests had a greater substrate moisture content and corresponding higher cohesive sand line (hereafter CSL) than beaches without nests. Beaches with nests also had a higher CSL than beaches with only crawls. Apparently, turtles could not excavate a nest chamber above the CSL due to loose substrate consistency causing sand to fall in on itself. Turtles could only nest at low elevations below the CSL on beaches with lower substrate moisture. Turtles apparently avoided nesting on these beaches due to the higher probability of nest flooding, as corroborated by a concurrent study. Beach temperatures increased with a seasonal increase in air temperatures, and were influenced by aspect and total angle of solar exposure. Temperatures did not differ among beaches with nests, beaches with only crawls, and beaches without crawls or nests. Therefore, there was no indication that turtles were manipulating offspring sex through choice of nesting beach. However, turtles may be manipulating sex by nesting in areas with particular thermal characteristics within beaches. Two related aspects of hatchling emergence were studied. Using emergence phenology data, nest temperatures, historical weather data, and a developmental model, I tested the hypothesis that delayed hatching occurred in C. insculpta, and that such a delay would allow hatchlings to time their emergence to match the onset of the wet season. Hatchling C. insculpta emerged, on average, 17 days later than dates predicted from a developmental model. Combined with observations of hatchlings remaining in eggs until emergence, these results confirmed delayed hatching in nature. This delay was synchronized with initial river rises associated with the onsetof wet season rains, and is consistent with published criteria for embryonic aestivation. On a diel scale, I generated predictions of two potentially competing models for nocturnal emergence in hatchling turtles, based on the knowledge that air temperatures decrease with season during the emergence period. A test of those predictions for C. insculpta produced ambiguous results. However, further analysis indicated that C. insculpta, and probably other nocturnally emerging turtle species, respond to a decline in diel temperature rather than an absolute temperature. The former would ensure nocturnal emergence, while the latter is experienced during the day as well as at night. Nocturnal emergence may be associated with nesting in open microhabitats. The 'decision' of when and where to nest can influence both offspring survival and hatchling sex ratios in animals with temperature-dependent sex determination (TSD). Knowledge of how these maternal attributes influence the incubation environment is an important first step in hypothesizing why TSD evolved in a particular species. 1 studied the influence of nest site choice and timing of nesting on embryonic survival and hatchling sex ratios. Predation and flooding were the major sources of embryonic mortality. Embryonic survival was influenced by both lay date and nest site choice: In one year when nesting began later, nests laid later and at lower elevations were destroyed by early wet season river rises. In other years early nesting precluded flood mortality. However, turtles did not nest at the highest available elevations. I hypothesized that turtles were unable to nest at higher elevations because the sand was dry and not cohesive. A field experiment demonstrated that turtles were constrained to nest at lower elevations where they could construct a nest chamber. A mathematical model predicting hatchling sex from fluctuating temperatures was applied to temperature data from 102 natural nests. Resultsconfirmed a type la pattern of TSD, whereby males are produced from cooler temperatures and females from warmer temperatures. The principal determinant of hatchling sex was lay date. Clutches laid earlier in the season produced mainly males, while later clutches yielded mostly females, due to seasonal ramping of air and sand temperatures. However, nest site choice also exerted an influence on hatchling sex. Female-producing clutches were deposited at higher elevations than male-producing clutches. The onset of nesting was not influenced by water temperatures, but may have been related to the magnitude of the previous wet season(s). Turtles nested earlier after two 'big' wet seasons and later following two 'small' wet seasons. This pattern indicates that the wet season is a plentiful time for the turtles. Adaptive 'differential fitness' models for the evolution of TSD have recently been reviewed and clarified. The differential fitness model that best fits C. insculpta is the 'timematching' model, whereby one sex benefits more than the other from early hatching. Male C. insculpta hatched 2-3 weeks earlier then females, on average. Benefit to early hatching males and, therefore, the ultimate selective mechanism (e.g., growth, time to mature) is unknown. Obtaining such data will likely prove difficult in such a long-lived species. A recent adaptive explanation for the evolution and maintenance of temperaturedependent sex determination (TSD) in reptiles rests upon the assumption that mothers can predict or manipulate offspring sex. I postulated that four physiological and behavioural criteria must be met in order for this assumption to be valid: (1) a strong correlation must exist between substrate temperatures during nest site choice and nest temperatures during the period of development when sex is determined in the egg (thermosensitive period = TSP). (2) Assuming that (1) is possible, mothers would need to be capable of correcting for temporal factors obscuring the predictable thermalcharacteristics of nest sites. This could be accomplished in two ways. By contracting nesting times mothers could assess the relative temperatures of alternate nest sites with some accuracy. A protracted distribution of nesting times could greatly reduce a mother's ability to distinguish between, for example, a cooler nest site at a warmer time and a warmer nest site at a cooler time. Alternatively, mothers would need to be able to incorporate temporal changes in nest site temperatures. (3) Sufficient variation in thermal profiles among nest sites, relative to the breadth of temperatures producing both sexes (pivotal temperatures), would be necessary. For example, if most nests produced both sexes, then depth of the eggs would be the deciding factor determining sex, leaving little opportunity for nest site choice to produce one sex or the other. (4) Mothers would need access to nest sites spanning a range of thermal profiles in order to produce either offspring sex. To this end, home range size relative to the number and location of nesting beaches should be important. I tested these four predictions in Carettochelys insculpta, a beach nesting turtle with TSD, using three years of field data on nest site choice, nesting times, thermal characteristics of nests, hatchling sex ratios, and movements of nesting turtles. A strong positive correlation existed between assessable substrate temperatures at nest site choice and mean daily TSP temperatures in all three years. However, the proportion of explained variation was highly variable among years, and low in 1998. Accordingly, the proportion of nests in which substrate temperatures at nest site choice predicted offspring sex correctly was low in 1998 (48- 62 %, depending on treatment of the data). Nesting times were normally distributed, and combined with diel changes in nest site temperatures greatly reduce a turtle's ability to distinguish between sites that would produce different sexes. Considerable among-clutch variation in thermal profiles to produce variable sex ratios existed, agreeing with other studies on turtles. Radiotelemetry indicated that home rangesencompassed several nesting beaches with differing thermal profiles, indicating scope for producing the desired sex. However, the seasonal increase in air temperatures resulted in an overriding effect of mostly males being produced in early (first) clutches and mainly females being produced in late (second) clutches. Collectively, the results suggest that C. insculpta mothers would find it difficult to predict, and therefore, manipulate hatchling sex, supporting the conventional notion that TSD mothers have little or no control over offspring sex.

Monoecy, the production of distinct male and female flowers on the same plant, is an important, though little studied, sexual strategy in the rainforest understory. This study of a monoecious plant discovered a cue to induce flowering, explored the interplay of gender constraint vs. plasticity in a natural population, and tested possible causes of gender in two laboratory experiments. An experiment in the lab found that reduced photoperiod for three weeks is an unambiguous cue for flowering. The remarkably long inductive period is followed by a long and variable period of floral initiation. This results in only partial synchronization of flowering among plants in a patch, which enhances mating opportunities in this protandrous plant. Inflorescence architecture is highly constrained, and ideally produces a phenotypic gender (proportion female) of about 0.5. However, in the forest at Las Cruces, Costa Rica, most plants were less female than predicted, mostly through abortion of female buds. Plants showed gender plasticity between and within years. Large plants produced more flowers and were more female in gender, and less variable in gender, than small plants. Reproduction was poorly correlated with environmental resource availability, measured as canopy openness, soil moisture, pH, and soil phosphorus, ammonium and nitrate. Phenotypic selection analysis on seed production suggests an optimal gender of 50-60% female, yet plasticity to be less female than this optimum, and in particular to express only male function, has been maintained. In a factorial experiment in the lab, high light or high nitrogen caused plants to produce more flowers and to be proportionally more female, and larger in weight, than low light or nitrogen. The effects of light and nitrogen on reproduction, plant size, and leaf greenness suggest an energy based determination of gender. Gender may be mostly influenced by plant size, but sometimes also opportunistically by environment. Inoculation with mycorrhizas caused plants to be less female in gender, and smaller in weight, than plants that were not inoculated. This suggests a net cost of mycorrhizas under experimental conditions, and supports the emerging view of the mycorrhizal symbiosis as not necessarily mutualistic under all circumstances.

The purpose of the study was to examine if intrinsic motivation and work commitment to the organization differs between permanent doctors and hired doctors. The total of 63 doctors who participated in the study made an internet-based survey with 21 questions taken from the Basic Need Satisfaction at Work Scale and 3 questions from the section “work commitment” in QPS Nordic. The main results of the study showed that permanent doctors perceived a higher level of intrinsic motivation on all the three needs autonomy, competence and relatedness. Furthermore the result showed a tendency that permanent doctors perceived a higher level of work commitment to the organization then hired doctors. / Syftet med studien var att undersöka om inre arbetsmotivation samt engagemang i organisationen skiljer sig mellan tillsvidareanställda och inhyrda läkare. Det gjordes genom en internetbaserad enkät som skickades ut till fem av Sveriges landsting. De totalt 63 läkarna som deltog i studien fick besvara totalt 21 frågor hämtade från Basic Need Satisfaction at Work Scale och 3 frågor från delen “engagemang i organisationen” i QPS Nordic. Studiens huvudresultat visade på att tillsvidareanställda läkare upplever en högre grad av inre motivation på alla tre behoven autonomi, kompetens och samhörighet. Resultatet visade också på en stark tendens till att tillsvidareanställda läkare upplevde högre grad av engagemang i organisationen än inhyrda läkare.

Be it the Algerian National Liberation Front, the African National Congress in South Africa or the continued struggle of the Palestinian people, the principle of self-determination is largely central to all projects of national liberation. This paper addresses what is arguably a deficient conception of self-determination by highlighting two factors that contributed to this deficiency. The first is the re-enforcement of dependency in self-determination projects by international institutions, primarily through the Mandate System. The second is a merit-based system of conditionality for the granting of independence, accompanied by a tendency to deformalize the law, relegating self-determination to an empty principle, the substance of which is decided by the negotiations’ context. The case of Palestine is used to demonstrate how those factors are adopted as central means in resolving the Palestinian self-determination problem, which in-turn leads to a deficient conception that does not account for the core content of the right.

Be it the Algerian National Liberation Front, the African National Congress in South Africa or the continued struggle of the Palestinian people, the principle of self-determination is largely central to all projects of national liberation. This paper addresses what is arguably a deficient conception of self-determination by highlighting two factors that contributed to this deficiency. The first is the re-enforcement of dependency in self-determination projects by international institutions, primarily through the Mandate System. The second is a merit-based system of conditionality for the granting of independence, accompanied by a tendency to deformalize the law, relegating self-determination to an empty principle, the substance of which is decided by the negotiations’ context. The case of Palestine is used to demonstrate how those factors are adopted as central means in resolving the Palestinian self-determination problem, which in-turn leads to a deficient conception that does not account for the core content of the right.

The purpose of this study was to investigate the dynamics of motivational forces in career stages in legendary table tennis players. Participants invited for this study were two highly recognized Swedish table tennis players who achieved major titles during their competitive career. The theoretical frameworks included the self-determination theory (SDT; Ryan & Deci, 1985, 2000), achievement goal theory (AGT; Nicholls, 1989), and the developmental model of transition faced by athletes (Wylleman & Lavallee, 2004). The study was based on in-depth narrative interviews on the field where the researcher stimulated participants to tell their stories in retrospect based on their perceptions of motivational drives across different stages. Results revealed that participants were (a) strongly driven by multiple personal goals (e.g., self-determined, winning major titles), (b) had high perception of ability (e.g., high task and high ego), (c) table tennis was central to their lives, and (d) they were surrounded by facilitative environment. Results are discussed in relation to theoretical frameworks and previous research. / Syftet med föreliggande studien var att undersöka dynamiken i motivationsprosessen genom olika karriärövergångar hos legendariska bordtennisspelare. Två välkända svenska bordtennisspelare deltog i studien som har vunnit stora titlar under sina professionella karriärer. De teoretiska ramverk som användes var self-determination theory (SDT; Ryan & Deci, 1985, 2000), achievement goal theory (AGT; Nicholls, 1989) och developmental model of transition faced by athletes (Wylleman & Lavallee, 2004). Studien var baserad på två djup-narrativa intervjuer där deltagarna stimulerades att i retrospekt berätta hur de upplevde dynamiken i deras motivation i olika karriärövergångar. Resultaten visade att deltagarna var (a) stärkt drivna av multipla personliga mål (själv-bestämd, vinna stora titlar), (b) hade hög upplevd förmåga (hög uppgift och hög prestationsmål), (c) bordtennis var central i deras liv, och (d) de var omringade av stödjande miljöer. De erhållna resultat diskuteras i relation till teoretiska ramverk och tidigare forskning.

Studiens syfte: Vårt syfte är att med hjälp av en enkätundersökning och etablerade motivationsteorier ta reda på vad som motiverar konsumenter inför ett bostadsköp. Metod: Vi har använt oss av en kvantitativ metod och informationen har samlats in med hjälp av en elektronisk enkätundersökning för att sedan kopplas till Self Determination Theory (SDT). Resultat & slutsats: Resultatet analyserades med hjälp av statistikprogrammet SPSS. Faktoranalysen resulterade i 13 faktorer, vilket slutligen gav en bild av 6 olika typer av konsumenter som alla motiveras på olika sätt. Förslag till fortsatt forskning: SDT skulle kunna användas på fler konsumentområden såsom upplevelser, resor eller för att ta reda på varför vi köper olika typer av varor. Uppsatsens bidrag: Vårt examensarbete har bidragit med att identifiera de motiv som driver oss till bostadsköp. Studien har visat att SDT kan vara ett lämpligt verktyg för framtidens fastighetsmäklare och att resultatet kan vara användbart i fastighetsmäklarrollen. / Aim of the study: The aim is to investigate consumers underlying motivation when they buy a house or a unit. This will be based on a survey and established theories of motivation such as Self Determination Theory. Method: We have used a quantitative method and the information was gathered from an electronic survey. Result & Conclusions: The statistical program SPSS was used to analyze the responses of the survey. To find the underlying correlations among the questions, we conducted a factor analysis. It resulted in 13 factors, which were narrowed down to 6 different types of consumers. Suggestions for future research: SDT can be used in different fields of consumer behaviour such as tourism and travelling, or to find out why we buy different types of goods. Contribution of the thesis: This thesis has contributed to the identification of the underlying motives behind buying a home. The study shows that SDT can be a suitable tool in marketing for future real estate agents.

Hydraulic fracturing plays an important role in increasing production rate in tight reservoirs. The performance of the reservoir after fracturing can be observed from the productivity index. This parameter is dependent on the fracture geometry; height, length and width. Unified fracture design (UFD) offers a method to determine the fracture dimensions providing the maximum productivity index for a specific proppant amount. Then, in order to achieve the maximum productivity index, the treatment schedules including the amount of liquid and proppant used for each stage must be determined according to the fracture dimensions obtained from the UFD. The proppant number is necessary for determining the fracture geometry using the UFD. This number is used to find the maximum productivity index for a given proppant amount. Then, the dimensionless fracture conductivity index corresponding to the maximum productivity index can be computed. The penetration ration, the fracture length, and the propped fracture width can be computed from the dimensionless fracture conductivity. However, calculating the proppant number used in UFD requires the fracture height as an input. The most convenient way to estimate fracture height to input to the UFD is to assume that the fracture height is restricted by stress contrast between the pay zone and over and under-lying layers. In other words, the fracture height is assumed to be constant, independent of net pressure and equal to the thickness of the layer which has the least minimum principal stress. However, in reality, the fracture may grow out from the target formation and the height of fracture is dependent on the net pressure during the treatment. Therefore, it is necessary to couple determination of the fracture height with determination of the other fracture parameters. In this research, equilibrium height theory is applied to rigorously determine the height of fracture. Solving the problem iteratively, it is possible to incorporate the rigorous fracture height determination into the unified fracture design.

Šiame magistro darbe išnagrinėtas Vilniaus miesto ir Vilniaus rajono mokyklų 9-12 klasių moksleivių profesinis apsisprendimas. Magistro darbo tikslas – remiantis naujausiais tyrimo rezultatais sudaryti Vilniaus miesto ir Vilniaus rajono mokyklų 9-12 klasių moksleivių profesinio apsisprendimo lyginamąją charakteristiką. Iškelti tyrimo uždaviniai: nustatyti, kokios profesijos pačios populiariausios tarp Vilniaus miesto ir Vilniaus rajono moksleivių, išsiaiškinti, ar moksleiviai pakankamai susipažino su pasirenkama profesija, palyginti profesinio apsisprendimo motyvus, sužinoti mokinių požiūrį į išsimokslinimą, išsiaiškinti, ar tėvų išsilavinimas daro įtaką moksleivių profesiniam apsisprendimui.Atlikto tyrimo išvados: miesto moksleiviai labiau linkę mokytis aukštojo mokslo įtaigose, jiems svarbu pasirinkti pelningą profesiją, susikurti tvirtą materialinį pagrindą, tapti savarankiškais, didesnė dalis Vilniaus rajono mokinių labiau orientuojasi į kolegijas ar profesines mokyklas, jiems renkantis profesiją padeda apsispręsti individo sugebėjimai, polinkiai ir interesai. Lyginant respondentų grupes pastebėta, kad tėvų išsilavinimas turi didelę įtaką mokinių požiūriui į mokslą ir profesinį pasirinkimą. / In this MA thesis career determination of 9-12 form students in Vilnius city and Vilnius region‘s secondary schools is researched. The aim of this MA thesis is to conduct a comparative study of 9-12 form students‘ career determination in Vilnius city and Vilnius region‘s secondary schools. The goals of the study are as follows: to identify the most popular professions among the students of Vilnius city and Vilnius region‘s secondary schools; to find out whether the students are sufficiently acquainted with the chosen future professions; to compare the students‘ motives for career choices; to find out the students‘ attitude towards education; to discover whether parents‘education has any influence on the students‘career choice. The findings of the study are as follows: students from the city schools are more inclined to study in the institutions of higher education; for them it is important to choose a financially rewarding profession, to establish a sound material base and to become independent; whereas a major part of students from Vilnius region secondary schools are more oriented towards colleges and vocational schools; individual abilities, dispositions and interests help them to make career choices. The comparison of the two respondent groups makes it explicit that parents‘education has a great influence on students‘attitude towards education and career choices.

The analysis, verification and emulation of attitude control hardware for nanosatellite spacecraft is described. The overall focus is on hardware that pertains to a multitude of missions currently under development at the University of Toronto Institute for Aerospace Studies - Space Flight Laboratory. The requirements for these missions push the boundaries of what is currently the accepted performance level of attitude control hardware. These new performance envelopes demand new acceptance test methods which must verify the performance of the attitude control hardware. In particular, reaction wheel and hysteresis rod actuators are the focus. Results of acceptance testing are further employed in post spacecraft integration for hardware emulation. This provides for a reduced mission cost as a function of reduced spare hardware. The overall approach provides a method of acceptance testing to new performance envelopes with the benefit of cost reduction with hardware emulation for simulations during post integration.