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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

LIMITATIONS OF HOST PLANT USE IN TWO ANDEAN ALTINOTE (NYMPHALIDAE, HELICONIINEA, ACRAEINI), BUTTERFLIES, FROM A TRITROPHIC PERSPECTIVE.

Pedersen, Karen M. 11 May 2015 (has links)
No description available.
12

Spatial and Temporal Dependent Shifts in Grassland Invasibility

Pfeil, Erin 17 November 2010 (has links)
No description available.
13

Goodwill som en resultatjusterare : påverkar ledningens handlingsutrymme redovisningen av goodwill? / Goodwill as an adjuster of results : does management discretion affect the recognition ofgoodwill?

Andersson, Eric, Jeppsson, Johan January 2018 (has links)
Sedan år 2005 måste samtliga svenska börsnoterade företag presentera sin finansiella information samtredovisningen av densamma i enlighet med standarden IFRS. Detta har resulterat i att företagsledningenssubjektiva tolkningar, något som skapat möjligheter för ledningen att påverka redovisningen. Detta kanförklaras genom Agency Theory och Positive Accounting Theory, vilka beskriver att ledningen antas ageraopportunistiskt, i syfte att maximera sin egennytta. Ledningen tenderar att manipulera företagsredovisning, varav goodwill kan användas som en resultatjusterare.Denna studie belyser hur ledningens handlingsutrymme påverkar företags redovisning av goodwill,betingat av den organisatoriska nivån. Studiens hypoteser formas utifrån organisationsnivåns olikafaktorer, vilka även testas för att se hur faktorerna påverkar företags redovisning av goodwill. För attundersöka studiens syfte används en positivistisk forskningsfilosofi och därmed kvantitativforskningsdesign, vilket präglas av en deduktiv ansats. Insamling av data har åstadkommits via företagsårsredovisningar, något som sedan sammanställts.Studiens resultat indikerar att ju högre skuldsättning och starkare ägarkoncentration, desto mindregoodwill redovisar ledningen. Har företag en låg skuldsättning och svag ägarkoncentration leder det tillökat handlingsutrymme och därmed en potentiellt högre andel redovisad goodwill.Studien bidrar till insikt kring hanteringen av goodwill och att ledningens handlingsutrymme har enpotentiell inverkan på redovisningen av goodwill. Dessutom tillför studien kunskap för vilka faktorer sompåverkar företags redovisningsval. Avslutningsvis bidrar uppsatsen till ökade möjligheter att jämförastudiens resultat med tidigare studier, vilket kan resultera i att ägarna kan få mer kännedom om hur debäst reducerar ledningens handlingsutrymme och dess opportunistiska beslut. / Since year 2005 all Swedish listed companies has to present their financials and accountingaccording to the standard IFRS. This has allowed the management to make subjectiveinterpretations, which in turn has elaborated opportunities to influence the accounting. Thosepossibilities can be explained by Agency Theory and Positive Accounting Theory, which presumethe management acting opportunistically, in order to maximize self-interest. Management tend tomanipulate companies accounting, whereof goodwill can be used as an adjuster of results.The thesis disambiguate how management discretion affect companies accounting of goodwill,contingent of the organizational level. The thesis hypothesis elaborates thru factors of theorganizational level, which are also tested in order to see how the variables affect businesscorporations accounting of goodwill. A positive research philosophy is used in order to analyze thethesis purpose. The data collection has been accomplished using the company's annual reports.The thesis results indicates that the higher debt and stronger concentration of ownership, the lessamount goodwill is accounted. If companies has a lower debt and weaker concentration ofownership, it increases management discretion and thereby a potentially higher amount of goodwill.The thesis contribute to knowledge about managing goodwill and that management discretion hasa potentially impact on the accounting of goodwill. Finally, the thesis contributes to increasedopportunities to compare the thesis results with previous studies, which may result in the ownersbeing able to get more knowledge of how they best reduce management discretion and itsopportunistically decisions.
14

Green Sea Turtles (Chelonia mydas) in Bermuda Exhibit an Ontogenetic Diet Shift despite Overexploitation of Resources in their Developmental Habitat

Burgett, Claire Margaret 27 March 2017 (has links)
Green sea turtles in Bermuda are overgrazing the seagrasses on which later life stages are thought to specialize. I hypothesized that larger green turtles in Bermuda would display individual diet specializations during seagrass scarcity. Stable isotope methods were used to determine the diet composition of green sea turtles from the Bermuda Platform as a function of size class and in turtles captured in successive years. Individual turtles had a wide range of diets, however, the variation in diets was driven by differences among size class rather than within the size classes of larger turtles, indicating that green turtles undergo a dietary ontogenetic shift during their residency on the Bermuda Platform and no clear specialization of diets among late-stage individuals. The apparent lack of dietary specialization of larger turtles indicates that older turtles are not diversifying their diets in response to the drastic reductions in seagrass in Bermuda.
15

Dimorfismo sexual na tesourinha Labidura xanthopus (Dermaptera): uma abordagem macro-ecológica a padrões e processos / Sexual dimorphism in the earwig Labidura xanthopus (Dermaptera): a macroecological approach to patterns and process

García-Hernández, Solimary 03 August 2015 (has links)
O dimorfismo sexual varia consideravelmente entre populações dentro de uma mesma espécie. Essa variação na direção e na magnitude do dimorfismo sexual é, em parte, devida às diferenças sexuais na respostas plásticas às condições e aos recursos ambientais. Por meio de experimentos em laboratório, sabe-se que a temperatura e a disponibilidade de alimento são fatores importantes na geração de variações morfológicas inter-individuais e que seus efeitos diferem entre machos e fêmeas. Usamos indivíduos da tesourinha Labidura xanthopus (Dermaptera) coletados em 20 localidades ao longo da costa brasileira para investigar como o tamanho corporal e o tamanho do armamento de machos e fêmeas variam em um gradiente natural de temperatura. O tamanho do corpo diminuiu com o aumento da temperatura, mas o dimorfismo sexual se manteve constante ao longo do gradiente de temperatura. Para o tamanho do armamento, encontramos uma relação negativa para machos e positiva para fêmeas. Conseqüentemente, a magnitude do dimorfismo sexual no tamanho do armamento diminuiu ao longo do gradiente de temperatura. Para entender o efeito da disponibilidade de alimento sobre a expressão de características morfológicas em cada um dos sexos, manipulamos a dieta durante o desenvolvimento de indivíduos provenientes de uma população de clima tropical e uma de clima temperado. Independente da população, o dimorfismo sexual foi causado por diferenças sexuais na dependência de condição. Machos e fêmeas diferiram não apenas na magnitude da resposta, mas também na direção. Em relação ao comprimento relativo dos fórceps, em particular, os resultados obtidos em laboratório não apóiam que a variação encontrada em campo se deve à disponibilidade de alimento. Outros fatores que não levamos em consideração, tais como densidade populacional, podem exercer um papel importante na resposta de machos e fêmeas em relação ao tamanho do armamento. Por fim, mais estudos experimentais comparando populações com diferenças marcantes de condições ambientais poderão lançar luz sobre quais fatores ecológicos podem ter favorecido a evolução do dimorfismo sexual dependente de condição / Sexual dimorphism varies considerably among populations within species. This variation in the direction and magnitude of sexual dimorphism is partially explained by sexual differences in phenotypically plastic responses to environmental conditions and resource availability. Laboratory experiments have already shown that temperature and food availability are important factors promoting inter-individual morphological variation and that their effects differ between males and females. We used individuals of the earwig Labidura xanthopus (Dermaptera) collected from 20 Brazilian localities to investigate how body size and weapon size of males and females vary across a natural temperature gradient. Body size decreased with increasing temperature, but sexual size dimorphism remained constant across the temperature gradient. For weapon size, we found a negative relationship for males and a positive relationship for females. Thus, the magnitude of sexual dimorphism in weapon size decreased across the temperature gradient. To understand the effect of food availability on the expression of morphological traits in each sex, we manipulated the diet of individuals from a tropical and temperate population. Regardless of the population, sexual dimorphism was caused by sex-differences in condition dependence. Males and females differed not only in the magnitude of their responses, but also in the direction. Regarding the relative length of the forceps, in particular, our results do not support the interpretation that the morphological variation observed in the field is explained by differences in food availability. Other factors not considered here, such as population density, may play an important role in determining weapon size variation in males and females under natural conditions. Finally, more experimental studies comparing populations with marked differences in environmental conditions may shed light on which ecological factors have favored the evolution of condition-dependent sexual dimorphism
16

Diversity, composition and seasonality of wild bees (Hymenoptera: Apoidea) in a northern mixed-grass prairie preserve

Patenaude, Andrea M. 14 September 2007 (has links)
The objective of this study was to characterize the wild bee fauna of a managed mixed-grass prairie in southwestern Manitoba. Weekly sampling using two methods, sweep-netting and bee bowls, was conducted over two years (2005-2006) at three sites within the Yellow Quill Mixed-grass Prairie Preserve. Spatial and seasonal patterns in diversity indices, taxonomic composition and ecological composition of the bee fauna were identified and investigated in relation to sampling method, environmental conditions, and floral resource availability. A total of 7014 individual bees representing five families and 100 species were collected. Numerically, social nesters from the genera Lasioglossum and Bombus dominated, while mining species of Andrena represented the greatest species richness. Observed spatial and seasonal patterns in the abundance, diversity and composition of the bee community were strongly modified by sampling method, resource limitation in the second year and the presence of the exotic invasive plant leafy spurge (Euphorbia esula). / October 2007
17

Diversity, composition and seasonality of wild bees (Hymenoptera: Apoidea) in a northern mixed-grass prairie preserve

Patenaude, Andrea M. 14 September 2007 (has links)
The objective of this study was to characterize the wild bee fauna of a managed mixed-grass prairie in southwestern Manitoba. Weekly sampling using two methods, sweep-netting and bee bowls, was conducted over two years (2005-2006) at three sites within the Yellow Quill Mixed-grass Prairie Preserve. Spatial and seasonal patterns in diversity indices, taxonomic composition and ecological composition of the bee fauna were identified and investigated in relation to sampling method, environmental conditions, and floral resource availability. A total of 7014 individual bees representing five families and 100 species were collected. Numerically, social nesters from the genera Lasioglossum and Bombus dominated, while mining species of Andrena represented the greatest species richness. Observed spatial and seasonal patterns in the abundance, diversity and composition of the bee community were strongly modified by sampling method, resource limitation in the second year and the presence of the exotic invasive plant leafy spurge (Euphorbia esula).
18

Diversity, composition and seasonality of wild bees (Hymenoptera: Apoidea) in a northern mixed-grass prairie preserve

Patenaude, Andrea M. 14 September 2007 (has links)
The objective of this study was to characterize the wild bee fauna of a managed mixed-grass prairie in southwestern Manitoba. Weekly sampling using two methods, sweep-netting and bee bowls, was conducted over two years (2005-2006) at three sites within the Yellow Quill Mixed-grass Prairie Preserve. Spatial and seasonal patterns in diversity indices, taxonomic composition and ecological composition of the bee fauna were identified and investigated in relation to sampling method, environmental conditions, and floral resource availability. A total of 7014 individual bees representing five families and 100 species were collected. Numerically, social nesters from the genera Lasioglossum and Bombus dominated, while mining species of Andrena represented the greatest species richness. Observed spatial and seasonal patterns in the abundance, diversity and composition of the bee community were strongly modified by sampling method, resource limitation in the second year and the presence of the exotic invasive plant leafy spurge (Euphorbia esula).
19

A redução na disponibilidade de recursos florais aumenta o tempo de forrageamento de abelhas sem ferrão (Melipona subnitida, Apidae, Meliponini) / The reduction in the availability of floral resources increases the foraging time of stingless bees (Melipona subnitida, Apidae, Meliponini)

Pereira, Jaciara da Silva 04 April 2017 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2018-03-27T20:23:50Z No. of bitstreams: 1 JaciaraSP_DISSERT.pdf: 2270128 bytes, checksum: 3ed201108d97d3b3c22c5679daa6908d (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:59:09Z (GMT) No. of bitstreams: 1 JaciaraSP_DISSERT.pdf: 2270128 bytes, checksum: 3ed201108d97d3b3c22c5679daa6908d (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:59:24Z (GMT) No. of bitstreams: 1 JaciaraSP_DISSERT.pdf: 2270128 bytes, checksum: 3ed201108d97d3b3c22c5679daa6908d (MD5) / Made available in DSpace on 2018-06-18T16:59:38Z (GMT). No. of bitstreams: 1 JaciaraSP_DISSERT.pdf: 2270128 bytes, checksum: 3ed201108d97d3b3c22c5679daa6908d (MD5) Previous issue date: 2017-04-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The abundance of flowering plants around the nests shapes the nest-internal and nest-external activities of social bee colonies. In addition to limiting the quantity of resources collected, the availability of floral resources in the environment may influence the distance that foragers have to fly in order to collect food. With decreasing abundance of flowering plants, bees more likely visit distant resources and, consequently, increase their flight range in search for new food sources. The semiarid region in north-eastern Brazil, the Caatinga, is characterized through a short rainy season with a high availability of floral resources on the one hand, and, on the other hand, through an extended dry season during which only few tree species are in bloom. In face of this striking difference concerning the availability of floral resources in the course of the year in this region, the aim of the present study was to assess the time that foragers of Melipona subnitida (Apidae, Meliponini) need to collect food (nectar and pollen) during times of high and low abundance of flowering plants. We investigated the time spent by foragers to collect floral resources in three distinct landscapes of the Brazilian north-east: an urban area and an area with natural caatinga vegetation, both at Mossoró/RN, as well as a high-altitude humid forest enclave at Martins/RN. During the study (July of 2015 to August of 2016), we counted monthly the number of plant species in bloom in each study location. During one day in each month, we measured at each study location the foraging times of bees, marked previously for individual identification, from three colonies of M. subnitida, marking the exit and return times between 05h00 and 08h00. Additionally, we identified the respective resource collected (nectar or pollen) and determined the plant species visited by the individuals through analysis of their corbicula pollen loads or the pollen on their bodies. Our results indicate that the quantity of plant species around the nests had an impact on the time the bees spent for food collection. With decreasing availability of floral resources, the bees spent more time foraging. This implies a greater energy expenditure for bee in the absence of resources near the nest and bee will have to move to distant areas / A disponibilidade de recursos florais ao redor dos ninhos molda as atividades tanto internas como externas das colônias de abelhas sociais. Além de limitar a quantidade de recursos coletados, a disponibilidade de recursos florais no ambiente pode influenciar na distância percorrida pelas abelhas forrageiras durante a coleta de alimento. À medida que os recursos florais se tornam escassos, as abelhas são mais propensas a usar recursos mais distantes e, consequentemente, expandem sua distância de voo em busca de novas fontes florais. A região semiárida do nordeste brasileiro, a Caatinga, possui uma breve estação chuvosa com alta disponibilidade de recursos florais e, em contraste, uma estação seca com apenas algumas espécies arbóreas em floração. Considerando o contraste na disponibilidade de recursos florais ao longo do ano nessa região, o objetivo do presente estudo foi avaliar o tempo que as abelhas forrageiras da abelha Melipona subnitida gastam na coleta de alimento (néctar e pólen) durante os períodos com alta e baixa riqueza de plantas em floração. Foi investigado o tempo que as abelhas forrageiras gastam para coletar recursos florais em três paisagens do nordeste brasileiro: uma área urbana, uma área com vegetação natural de caatinga, ambas em Mossoró/RN e um Brejo de Altitude, em Martins/RN. Durante o estudo (junho de 2015 a agosto de 2016) foi registrado mensalmente o número de espécies de plantas em floração em cada ambiente. Mensalmente (um dia a cada mês), foi cronometrado o tempo de forrageamento de abelhas previamente marcadas para identificação individual, provenientes de três colônias de M. subnitida em cada local de estudo, registrando os horários de saída e entrada de abelhas forrageiras, no período entre 05:00 h e 08:00 h da manhã. Além disso, o respectivo recurso coletado (néctar ou pólen) foi identificado por meio da análise do pólen nas corbículas ou no corpo dos indivíduos. Os resultados indicam que a quantidade de recursos florais disponível ao redor dos ninhos influenciou o tempo gasto na coleta de alimento. Quanto menor a disponibilidade de recursos maior foi o tempo gasto pelas abelhas durante o forrageamento. Isso implica em um maior gasto energético para abelha, pois na ausência de recursos próximos ao ninho a abelha terá que se deslocar para áreas distantes / 2018-03-27
20

Dimorfismo sexual na tesourinha Labidura xanthopus (Dermaptera): uma abordagem macro-ecológica a padrões e processos / Sexual dimorphism in the earwig Labidura xanthopus (Dermaptera): a macroecological approach to patterns and process

Solimary García-Hernández 03 August 2015 (has links)
O dimorfismo sexual varia consideravelmente entre populações dentro de uma mesma espécie. Essa variação na direção e na magnitude do dimorfismo sexual é, em parte, devida às diferenças sexuais na respostas plásticas às condições e aos recursos ambientais. Por meio de experimentos em laboratório, sabe-se que a temperatura e a disponibilidade de alimento são fatores importantes na geração de variações morfológicas inter-individuais e que seus efeitos diferem entre machos e fêmeas. Usamos indivíduos da tesourinha Labidura xanthopus (Dermaptera) coletados em 20 localidades ao longo da costa brasileira para investigar como o tamanho corporal e o tamanho do armamento de machos e fêmeas variam em um gradiente natural de temperatura. O tamanho do corpo diminuiu com o aumento da temperatura, mas o dimorfismo sexual se manteve constante ao longo do gradiente de temperatura. Para o tamanho do armamento, encontramos uma relação negativa para machos e positiva para fêmeas. Conseqüentemente, a magnitude do dimorfismo sexual no tamanho do armamento diminuiu ao longo do gradiente de temperatura. Para entender o efeito da disponibilidade de alimento sobre a expressão de características morfológicas em cada um dos sexos, manipulamos a dieta durante o desenvolvimento de indivíduos provenientes de uma população de clima tropical e uma de clima temperado. Independente da população, o dimorfismo sexual foi causado por diferenças sexuais na dependência de condição. Machos e fêmeas diferiram não apenas na magnitude da resposta, mas também na direção. Em relação ao comprimento relativo dos fórceps, em particular, os resultados obtidos em laboratório não apóiam que a variação encontrada em campo se deve à disponibilidade de alimento. Outros fatores que não levamos em consideração, tais como densidade populacional, podem exercer um papel importante na resposta de machos e fêmeas em relação ao tamanho do armamento. Por fim, mais estudos experimentais comparando populações com diferenças marcantes de condições ambientais poderão lançar luz sobre quais fatores ecológicos podem ter favorecido a evolução do dimorfismo sexual dependente de condição / Sexual dimorphism varies considerably among populations within species. This variation in the direction and magnitude of sexual dimorphism is partially explained by sexual differences in phenotypically plastic responses to environmental conditions and resource availability. Laboratory experiments have already shown that temperature and food availability are important factors promoting inter-individual morphological variation and that their effects differ between males and females. We used individuals of the earwig Labidura xanthopus (Dermaptera) collected from 20 Brazilian localities to investigate how body size and weapon size of males and females vary across a natural temperature gradient. Body size decreased with increasing temperature, but sexual size dimorphism remained constant across the temperature gradient. For weapon size, we found a negative relationship for males and a positive relationship for females. Thus, the magnitude of sexual dimorphism in weapon size decreased across the temperature gradient. To understand the effect of food availability on the expression of morphological traits in each sex, we manipulated the diet of individuals from a tropical and temperate population. Regardless of the population, sexual dimorphism was caused by sex-differences in condition dependence. Males and females differed not only in the magnitude of their responses, but also in the direction. Regarding the relative length of the forceps, in particular, our results do not support the interpretation that the morphological variation observed in the field is explained by differences in food availability. Other factors not considered here, such as population density, may play an important role in determining weapon size variation in males and females under natural conditions. Finally, more experimental studies comparing populations with marked differences in environmental conditions may shed light on which ecological factors have favored the evolution of condition-dependent sexual dimorphism

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