Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-02-03T09:59:04Z No. of bitstreams: 2 Dissertação - Thiago Souza Azeredo Bastos - 2014.pdf: 2662232 bytes, checksum: 6d11a68317a80555fa7005a2f51b625b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-02-05T13:29:30Z (GMT) No. of bitstreams: 2 Dissertação - Thiago Souza Azeredo Bastos - 2014.pdf: 2662232 bytes, checksum: 6d11a68317a80555fa7005a2f51b625b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-05T13:29:30Z (GMT). No. of bitstreams: 2 Dissertação - Thiago Souza Azeredo Bastos - 2014.pdf: 2662232 bytes, checksum: 6d11a68317a80555fa7005a2f51b625b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-24 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Insects of Lutzomyia genus have considerable importance in the transmission of diseases such as bartonellosis, arboviruses, and especially visceral and cutaneous leishmaniasis, both diseases present in the city of Goiás, place chosen to capture insects using CDC traps during twelve months in order to study the existing population of sandflies. Traps were placed throughout the urban area repeatedly for three nights in the last weekend of each month between September 2012 and August 2013. At the same time of trapping insects, relevant eco-epidemiological data were collected. After captures, all sandflies were identified. Were encountered in the city of Goiás eight species, in a total of 370 captured. The species were: Lutzomyia longipalpis, Lutzomyia whitmani, Lutzomyia intermédia, Lutzomyia lenti, Lutzomyia shannoni, Lutzomyia peresi, Lutzomyia baculus and Lutzomyia goiana. The results obtained through analysis by Kruskal -Wallis test and Poisson distribution showed significance for the relationship formed between the amount of gathered sandflies with season and rural area characteristic. Although few sandflies were obtained, the presence of female L. longipalpis was associated with the human and canine visceral leishmaniasis cases. / Os insetos do gênero Lutzomyia tem considerável importância na transmissão de doenças como bartonelose, arboviroses e, principalmente, a leishmaniose visceral e a leishmaniose tegumentar amer icana, ambas presentes na cidade de Goiás, local escolhido para realizar capturas de insetos com armadilhas tipo CDC durante doze meses, a fim de estudar a população de flebotomíneos existentes. As armadilhas foram posicionadas ao longo de toda a área urbana, repetidamente por três noites seguidas, no último final de semana de cada mês, entre setembro de 2012 e agosto de 2013. Além da captura de insetos, foram coletados dados eco-epidemiológicos. Após a captura, todos os flebotomíneos foram identificados. Ao final, foram identificados oito espécies na cidade de Goiás, de um total de 370 capturados. As espécies identificadas foram: Lutzomyia longipalpis, Lutzomyia whitmani, Lutzomyia intermédia, Lutzomyia lenti, Lutzomyia shannoni, Lutzomyia peresi, Lutzomyia baculus e Lutzomyia goiana. Os resultados obtidos, através de análise feita pelo Kruskal-Wallis e pelo modelo linear generalizado com distribuição de Poisson, apresentaram significância para a relação formada entre a quantidade de flebotomíneos capturados e o estágio lunar, estação do ano e as áreas com características rurais. Apesar de terem sido capturados poucos flebotomíneos, contatou-se a presença de fêmeas da espécie L. longipalpis além de caso humano e canino de leishmaniose visceral.

This psychobiography on the life of Karen Horney is an exploratory-descriptive study that aims to explore and describe Horney's life structure development according to Daniel Levinson's (1996) theory of adult development. The method of research uses a qualitative single-case research design that studies her life over her entire lifespan and highlights the individual characteristics of Horney in a holistic manner within her socio-historical context. A purposive sampling procedure was used to select Karen Horney as the subject of the research and only published data was analyzed in the research. Multiple sources of data are used to obtain the information in this research, including an autobiography and three biographies written by three different authors. This data is organized according to the temporal sequence of her lifespan and the developmental periods and time frame of Levinson's theory. Horney's life is described and explored to highlight those areas of her life that conform to the developmental theory and those aspects of her life that are not included in the theoretical constructs of Levinson 's theory. By exploring the significant relationships that Horney developed throughout her life with family, friends, work colleagues, community and religious affiliations, and the important issues in her development, this study verifies Levinson's theory by corroborating his conceptualisation of adult development as a process of sequential stages divided into four main eras of development, linked by three periods of transition. A shortcoming of Levinson's theory relates to his omission of self-esteem issues and religious concerns as relevant factors experienced during the era of pre-adulthood and spiritual concerns during the era of late adulthood.

Five subtropical perennial grass species, Cenchrus ciliaris, a Cynodon hybrid, Digitaria eriantha subsp. eriantha, Panicum maximum and Pennisetum clandestinum, were subjected to four levels of water availability in a small plot trial under a rainshelter during the summer growing seasons of 1996/97 and 1997/98. This work was carried out on the Hatfield Experimental Farm of the University of Pretoria, Pretoria, South Africa. The average yields for the tufted species (C. ciliaris, D. eriantha and P. maximum) were lower in the 1997/98 than the 1996/97 season. C. ciliaris, however, produced the highest average yields in both seasons. The average yields of the Cynodon hybrid and P. clandestinum (creeping grasses) reacted differently, in that the average yields were higher in the 1997/98 than 1996/97 season. The dry matter yields of all five grass species at slight water deficits, were not significantly different from yields under conditions of no water shortages, when the soil profile was brought to field capacity at the beginning of the growing season. The implication hereof is, that dry matter yields can be maintained, in conditions where slight water deficits occur, if there is some water stored in the soil profile. C. ciliaris, a notable drought tolerant species, produced yields (11.7-20.0 t ha-1) under non-control conditions (W1, W2 and W3) which were comparable to yields obtained from traditionally irrigated grasses such as the Cynodon hybrid (12.0-15.8 t ha-1) and P. clandestinum (5.6-11.8 t ha-1), under control conditions (W4). P.clandestinum, D. eriantha and P. maximum tended to be better adapted to wetter conditions, while the Cynodon hybrid was also able to produce good yields under both water limiting and non-limiting conditions. Water use efficiency, regardless of the grass species, tended to be better under non-control conditions. Grasses were thus able to produce more dry matter per unit of water under conditions where water became scarce. In vitro dry matter digestibility was not negatively affected by water scarcity, while crude protein content more often than not seemed to be better under control conditions. This could be due to the uptake meganism of nutrients, in which water plays a vital role. The number of stoma per unit area was more under control than water limiting conditions. The expression of the different structures on the leaf surfaces, were not altered by the level of water availability. In the absence of water shortages, the growth rates of C. ciliaris, D. eriantha and P.maximum, were almost twice those of the Cynodon hybrid and P. clandestinum, as measured at the end of two growth cycles in an irrigated field trial. In a pot trial, under glasshouse conditions, with C. ciliaris, the Cynodon hybrid and P.clandestinum, both the level of water availability, and the level of nitrogen were varied. Regardless of species and level of nitrogen, water was still used more efficiently under non-control conditions. Higher levels of nitrogen did, however, improve water use efficiency regardless of level of water available. As with higher levels of available water, higher levels of nitrogen also improved yields. In this trial, the Cynodon hybrid and C. ciliarisalso out-yielded P. clandestinum.<,/p> In summary it can be said that C. ciliaris and the Cynodon hybrid are adapted to warm growing conditions in producing high yields regardless of the level of water available. D. eriantha, P. maximum and P. clandestinum would produce better in such growing conditions if water was not as limiting. Regardless of the species, the plants were able to use water more efficiently under non-control conditions, while in Vitro digestibility was not negatively affected by water limiting conditions. Due to the uptake mechanism of nutrients, water limiting conditions may, however, decrease the crude protein content of the grass plants. Higher levels of nitrogen had a positive impact on dry matter yields and water use efficiency. / Thesis (PhD)--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

Made available in DSpace on 2016-01-26T18:55:34Z (GMT). No. of bitstreams: 1 Aline Silva.pdf: 343244 bytes, checksum: 747b2ff671732dd29f9e774a854fb28c (MD5) Previous issue date: 2012-09-20 / The Bulls have a great influence on the genetic composition of livestock so it is necessary to know the evidence of modern evaluation and apply them, thus obtaining, breeding for reproductive traits through the use of semen quality. The spermiogram conjunction with techniques such as scrotal thermogram and electrophoresis, to detect possible proteins in seminal plasma markers of fertility may contribute significantly to the selection of superior breeding. This study will use 10 Nelore bulls aged 30 months raised on a farm in the municipality of Presidente Prudente-SP, which will be evaluated during 6 months of the year (spring and summer), will be held 12 semen samples with an interval of 15 days. Be done spermiogram electrophoresis on polyacrylamide gel (SDS-PAGE) and the measured surface temperature for half of the scrotum infrared thermometer for obtaining the temperature gradient scrotal animals. The environment will be monitored daily for the minimum and maximum temperatures and relative humidity. The goal from study to study the influence of climatic factors on the surface temperature of the scrotum, spermiogram and protein profile (SDS-PAGE) of seminal plasma in Nellore bulls in the spring and summer seasons. / Os touros têm uma grande influência sobre a composição genética dos rebanhos por isso é necessário conhecer as provas modernas de avaliação e aplicá-las, obtendo, assim, melhoramento genético para as características reprodutivas, por meio do uso de sêmen com qualidade. O espermiograma aliado às técnicas como termograma escrotal e a eletroforese, para detecção de possíveis proteínas do plasma seminal marcadoras de fertilidade poderão contribuir significativamente na escolha de reprodutores superiores. Neste estudo foram utilizados 10 touros da raça Nelore com idade de 24 meses criados em uma propriedade rural no município de Presidente Prudente SP, que foram avaliados durante os meses de agosto a novembro, quando foram realizadas 12 colheitas de sêmen com intervalo de 15 dias. Foram realizados o espermiograma, a eletroforese do plasma seminal em gel de poliacrilamida (SDS-PAGE), aferida a temperatura da superfície do escroto, por meio de termometria de infravermelho para a obtenção do gradiente de temperatura escrotal destes animais e dosagem sérica de testosterona e cortisol O ambiente foi monitorado diariamente, para as temperaturas mínima e máxima, umidade relativa do ar e índices pluviométricos. O objetivo desde estudo foi estudar a influência dos fatores climáticos na temperatura da superfície do escroto, espermiograma e perfil protéico (SDS-PAGE) do plasma seminal em touros Nelore, nas estações primavera e verão.

Made available in DSpace on 2016-07-18T17:53:10Z (GMT). No. of bitstreams: 1 Aline Silva.pdf: 343244 bytes, checksum: 747b2ff671732dd29f9e774a854fb28c (MD5) Previous issue date: 2012-09-20 / The Bulls have a great influence on the genetic composition of livestock so it is necessary to know the evidence of modern evaluation and apply them, thus obtaining, breeding for reproductive traits through the use of semen quality. The spermiogram conjunction with techniques such as scrotal thermogram and electrophoresis, to detect possible proteins in seminal plasma markers of fertility may contribute significantly to the selection of superior breeding. This study will use 10 Nelore bulls aged 30 months raised on a farm in the municipality of Presidente Prudente-SP, which will be evaluated during 6 months of the year (spring and summer), will be held 12 semen samples with an interval of 15 days. Be done spermiogram electrophoresis on polyacrylamide gel (SDS-PAGE) and the measured surface temperature for half of the scrotum infrared thermometer for obtaining the temperature gradient scrotal animals. The environment will be monitored daily for the minimum and maximum temperatures and relative humidity. The goal from study to study the influence of climatic factors on the surface temperature of the scrotum, spermiogram and protein profile (SDS-PAGE) of seminal plasma in Nellore bulls in the spring and summer seasons. / Os touros têm uma grande influência sobre a composição genética dos rebanhos por isso é necessário conhecer as provas modernas de avaliação e aplicá-las, obtendo, assim, melhoramento genético para as características reprodutivas, por meio do uso de sêmen com qualidade. O espermiograma aliado às técnicas como termograma escrotal e a eletroforese, para detecção de possíveis proteínas do plasma seminal marcadoras de fertilidade poderão contribuir significativamente na escolha de reprodutores superiores. Neste estudo foram utilizados 10 touros da raça Nelore com idade de 24 meses criados em uma propriedade rural no município de Presidente Prudente SP, que foram avaliados durante os meses de agosto a novembro, quando foram realizadas 12 colheitas de sêmen com intervalo de 15 dias. Foram realizados o espermiograma, a eletroforese do plasma seminal em gel de poliacrilamida (SDS-PAGE), aferida a temperatura da superfície do escroto, por meio de termometria de infravermelho para a obtenção do gradiente de temperatura escrotal destes animais e dosagem sérica de testosterona e cortisol O ambiente foi monitorado diariamente, para as temperaturas mínima e máxima, umidade relativa do ar e índices pluviométricos. O objetivo desde estudo foi estudar a influência dos fatores climáticos na temperatura da superfície do escroto, espermiograma e perfil protéico (SDS-PAGE) do plasma seminal em touros Nelore, nas estações primavera e verão.

Background: Vaccination is one of the most cost-effective preventive measures against infectious diseases. A proper administration of the vaccine is critical. Therefore, only authorized and trained health care personnel including pharmacists can administrate vaccines safely and effectively. However, in Sweden, several laws and regulations prevent pharmacists to perform vaccinations. Aim: The aim was to elucidate the conditions and regulations of influenza vaccination administration by pharmacists at pharmacies in other countries compared to Sweden. Methods: A literature review were performed. Two different databases, PubMed and Web of Science were used. In addition, reports of governmental and various organizations were used. Interviews have been used as a complement. Results: Involving pharmacists in vaccination administration improves the vaccine coverage. This result was confirmed by pharmacist performing vaccine administration in other countries such as the USA, Canada, UK and Norway. However, these benefits are limited in Sweden due to the regulation HSLF-FS 2017:37, which hampers vaccines administration by pharmacists. Nevertheless, the regulation SOSFS 1997:14 could be interpreted as allowing clinical doctors to delegate vaccination to pharmacists. However, this needs to be further investigated. All Swedish representatives interviewed in this report, supported the idea that pharmacists should be able to perform vaccines at Swedish pharmacies. Conclusions: Modification of the regulation HSLF-FS 2017: 37 as well as proper education and training are required to allow pharmacists to perform vaccinations in Swedish pharmacies.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The collaborative thesis with the Swedish Geotechnical Institute (SGI) investigates seasonal PFAS contamination spreading near Örnsköldsvik airport, where AFFF was used during fire drills from 1993 to 2008. Data analysis of 11 PFAS concentrations from November 2022 to October 2023 utilized scatterplots and time series graphs. In ArcMap, concentrations were interpolated to predict spatial spreading across four seasons. Geologically, the area features an upper aquifer confined by a clay layer, potentially with a lower aquifer. High PFAS concentrations in the upper aquifer occur during spring and autumn, except for PFHxA and PFBA, peaking in winter. Contamination primarily extends towards Varmyrän, with unexpected spread towards Bromyrän and the northeast area to the fire drill site. Significant spatial changes occur from winter to spring, and certain short-chain PFAS behave similarly in time and space. Limited data for the lower aquifer allowed analysis only during summer and autumn, revealing major spatial changes concentrated in the north of the fire drill area. In both layers, PFOS, PFHxS, and PFHxA present the highest concentration. Various factors influence PFAS movement, including groundwater levels, soil types, and precipitation, with seasonal groundwater data lacking. PFOS and PFHxS move towards Varmyrän within approximately 30 days, with additional movement towards the airport. Percolation from the upper to the lower aquifer could take around six months, with data limitations for winter and spring in the lower aquifer. Kriging is sensitive to point quantity, and normalization complicates absolute value comparisons from interpolations. This study highlights the need for comprehensive data collection, alternative methodologies for studying PFAS seasonal changes, and improved data visualization techniques to enhance understanding of PFAS dynamics in the groundwater. / Samarbetet med Statens geotekniska institut (SGI) undersöker säsongsbunden PFAS-föroreningsspridning nära Örnsköldsviks flygplats, där AFFF användes under brandövningar från 1993 till 2008. Dataanalys av 11 PFAS-koncentrationer från november 2022 till oktober 2023 använde scattergraphs och tidsseriediagram. . I ArcMap interpolerades koncentrationer för att förutsäga rumslig spridning över fyra årstider. Geologiskt har området en övre akvifär som är begränsad av ett lerlager, potentiellt med en lägre akvifär. Höga PFAS-koncentrationer i den övre akvifären förekommer under våren och hösten, förutom PFHxA och PFBA, som toppar på vintern. Föroreningarna sträcker sig i första hand mot Varmyrän, med oväntad spridning mot Bromyrän och det nordöstra området till brandövningsplatsen. Betydande rumsliga förändringar sker från vinter till vår, och vissa kortkedjiga PFAS uppträder på liknande sätt i tid och rum. Begränsade data för den nedre akvifären möjliggjorde analys endast under sommaren och hösten, vilket avslöjade stora rumsliga förändringar koncentrerade till norra delen av brandövningsområdet. I båda skikten har PFOS, PFHxS och PFHxA den högsta koncentrationen. Olika faktorer påverkar PFAS-rörelsen, inklusive grundvattennivåer, jordtyper och nederbörd, med säsongsbetonade grundvattendata saknas. PFOS och PFHxS rör sig mot Varmyrän inom cirka 30 dagar, med ytterligare förflyttning mot flygplatsen. Perkolering från den övre till den nedre akvifären kan ta cirka sex månader, med databegränsningar för vinter och vår i den nedre akvifären. Kriging är känsligt för punktkvantitet, och normalisering komplicerar absolutvärdesjämförelser från interpolationer. Denna studie belyser behovet av omfattande datainsamling, alternativa metoder för att studera PFAS säsongsförändringar och förbättrade datavisualiseringstekniker för att öka förståelsen för PFAS-dynamiken i grundvattnet.

The Earth harbors around 300 000 plant species. The rich and complex environment provided by plants is considered a key factor for the extraordinary diversity of the terrestrial fauna by, for example, providing food and shelter. This thesis contributes to the understanding of these questions by investigating how the interplay of physiology, demography, and evolution gives rise to variation and diversity in fundamental plant traits. This will help us answer questions such as: How has this amazing diversity of plant species emerged? Which mechanisms maintain diversity? How are plant strategies and plant diversity influenced by variations in the environment? A plant faces multiple problems to survive and reproduce successfully. These problems can be modeled by considering traits, trade-offs and a fitness measure. For example: How to maximize growth rate, while maximizing structural stability? I will investigate four plant models in order to understand the function of plants, and mechanisms promoting diversity.  Paper I: We study how annual plants with and without growth constraints should optimize their flowering time when productivity or season length changes. With a dynamic ontogenetic growth model and optimal control theory we prove that a bang-bang reproductive control is optimal under constrained growth and constant mortality rate. We find that growth constraints can flip the direction of optimal phenological response for increasing productivity. The reason is that the growth rate of vegetative mass saturates at high productivity and therefore it is better to flower earlier and take advantage of a longer reproductive period. If season length extends equally both in the beginning and the end of the season, growth constraints control the direction of the optimal response as well. Our theory can help explaining phenological patterns along productivity gradients, and can be linked to empirical observations made on a calendar scale. Paper II: We introduce a new measure of tree crown-rise efficiency based on the loss of biomass of the tree during growth. The more mass the tree looses during growth, the less crown-rise efficient it is. Top-heavy shapes loose more biomass than bottom-heavy shapes. Light-use efficiency is defined as the mean light assimilation of the leaves in the crown times the ratio of leaf mass and total mass. We then study the trade-off between light-use efficiency to crown-rise efficiency for tree crown shapes. We assume that the total tree mass is constant, and a constant vertical light gradient represent the shading from a surrounding forest. We find large differences in crown shapes at intermediate vertical light gradient, when both self-shading and mean-field shading are important, suggesting light-use vs crown-rise efficiency as a new trade-off that can explain tree diversity. Our crown-rise efficiency measure could easily be integrated into existing forest models. Paper III: We extend an evolutionary tree crown model, where trees with different heights compete for light, with drought-induced mortality rates depending on ground-water availability and the depth of an optional taproot. The model does not include competition for ground water. Our model explains how ground-water availability can shape plant communities, when taproot and non-taproot strategies can coexist, and when only one of these strategies can persist. We investigate how emerging plant diversity varies with water table depth, soil water gradient and drought-induced mortality rate. The taproot enables plants to reach deep water, thus reducing mortality, but also carries a construction cost, thus inducing a trade-off. We find that taproots maintain plant diversity under increasing drought mortality, and that taproots evolve when groundwater is accessible at low depths. There are no viable strategies at high drought mortality and deep water table. Red Queen evolutionary dynamics appear at intermediate drought mortality in mixed communities with and without taproots, as the community never reaches a final evolutionarily stable composition. Paper IV: We extend a size-structured plant model, with self-shading and two evolving traits, crown top-heaviness and crown width-to-height ratio. The model allows us to identify salient trade-offs for the crown shape. The most important trade-off for top-heaviness is light-use efficiency vs crownrise efficiency, and the most important trade-off for width-to-height ratio is self-shading vs branch costs. We find that when the two traits coevolve; the outcome is a single common evolutionarily stable strategy (ESS), far away from the highest net primary production (NPP). When only sun angle is decreasing with increasing latitude both the crown width-to-height ratio and crown top-heaviness decrease. However, when light response in addition to the sun angle decreases with increasing latitude, the crown width-to-height ratio is nearly invariant of latitude except at low site productivity when the ratio decreases with latitude. Top-heaviness is always decreasing with increasing latitude. Finally, we find that crown top-heaviness increases with the NPP or leaf-area index (LAI) at ESS, but crown width-to-height ratio is maximal at an intermediate NPP or LAI. / Artikel I: Arters reproduktionsframgång (fitness), till exempel antal avkommor eller frön som produceras under livet, är ofta avgörande för huruvida de är evolutionärt framgångsrika eller inte. Här undersöker vi hur ettåriga växter med eller utan tillväxtbegränsningar ska optimera sin blomningstid när produktivitet eller säsongslängd ändras. Det är optimalt att gå direkt från tillväxt till blomning när tillväxten är begränsad och dödligheten är konstant. Vid ökad produktivitet sker blomningen tidigare med tillväxtbegränsningar men senare utan tillväxtbegränsningar, vilket beror på att med tillväxtbegränsningar ökar den vegetativa massan långsamt. Därför är det bättre att blomma tidigare och ta tillvara på en längre reproduktionsperiod. Vi får samma resultat om säsongslängden ökar lika mycket i början och slutet av säsongen. Vår teori kan bidra till att förutsäga blomningstider vid produktivitetsförändringar och säsongsförändringar. Artikel II: Tillväxten hos träd kan begränsas av brist på ljus, vatten, och näring, men också genom förlust av grenar. Vi introducerar ett nytt mått på tillväxteffektiviteten hos trädkronor baserat på förlust av biomassa under trädets tillväxt. Ju mer massa trädet förlorar under tillväxt, desto mindre tillväxteffektiva är de. Topptunga former förlorar mer biomassa än bottentunga former. Vi studerar avvägningar mellan ljuseffektivitet och tillväxteffektivitet för trädformer, där ljuseffektiviteten definieras som medelljusupptaget för löven i kronan. Vi antar en konstant totalmassa, och en statisk vertikal skuggning som representerar skuggningen från en omgivande skog. Vi hittar stora skillnader i kronformer vid en medelhög skuggning, då både självskuggningen och medelskuggningen har betydelse. Vårt mått för tillväxteffektivitet kan enkelt integreras i existerande skogsmodeller. Studien visar att avvägningar mellan tillväxteffektivitet och ljuseffektivitetet kan vara viktig för mångfalden av trädformer i en skog. En överraskande upptäckt är att konformade eller sfäriska trädkronor aldrig är effektiva, men däremot timglasformade kronor. Artikel III: Växter kan försvara sig på olika sätt mot torka, till exempel genom att rulla ihop bladen eller genom att reproducera tidigare och därigenom undvika uttdragen torka. Här undersöker vi fördelarna med en pålrot vid torka. En pålrot är en rot som växer nedåt för att nå djupliggande grundvatten. Vi utvidgar en evolutionär modell av trädkronor med grundvatten och en pålrot, där träd med olika höjd konkurrerar om ljus. Det finns ingen konkurrens om vatten. Vi undersöker hur mångfalden hos träden beror på vattendjup, vattengradient och dödlighet orsakad av torka. Med hjälp av pålroten kan träden nå djupt vatten och därigenom minska dödligheten, men den medför också en kostnad, så en avvägning måste göras. Vi ser att pålrötter upprätthåller mångfalden hos växterna vid ökad mortalitet, och att pålrötter uppstår när grundvattnet är grunt. Det finns inga strategier som kan överleva om grundvattnet är djupt och dödligheten är hög. Vår modell kan förklara hur grundvatten kan förändra sammansättningen på trädsamhällen, när träd med och utan pålrot kan samexistera, och under vilka förutsättningar endast en av strategierna förväntas dominera. Artikel IV: Träd som växer upp i en skog måste konkurrera med andra träd om ljus, framförallt större träd. Detta ger upphov till en asymmetrisk ljuskonkurrens, där de små träden hämmas av större träd. Små träd har därmed små chanser att överleva utom då skogen nyligen störts och det öppnas upp en glänta. Vid denna ljuskonkurrens kan man anta att trädkronans form har stor betydelse för trädets framgång. Frågan är hur de evolutionärt fördelaktiga kronformerna beror på latituden och produktiviteten. Vi antar att latituden påverkar solens genomsnittliga vinkel och ljusrespons. Vi utvidgar en storleksstrukturerad trädmodell med självskuggning där två evolverande egenskaper beskriver kronans topptyngd och bredd. Med modellen kan vi undersöka vilka strategiska avvägningar som bestämmer om kronans form blir konkurrenskraftig. En topptung krona har högt ljusupptag eftersom det finns mest ljus högt upp i grenverket. Å andra sidan har den en låg tillväxteffektivitet eftersom topptunga kronor måste tappa mycket grenar för att behålla sin form. En bred krona har en låg självskuggning eftersom bladen är utspridda. Å andra sidan har den höga kostnader för de långa grenar som krävs. Vi finner att när dessa egenskaper evolverar tillsammans så finns endast en evolutionärt stabil strategi (ESS), långt från den högsta nettoproduktionen. När endast solvinkeln minskar med ökande latitud minskar både kronans bredd och topptyngd, men när både solvinkel och ljusrespons minskar med ökande latitud så är bredden nästan oförändrad utom vid låg produktivitet då den minskar med latituden. Kronans topptyngd minskar alltid med latituden. Slutligen ser vi hur kronans topptyngd alltid ökar med nettoproduktionen vid ESS, medan kronans bredd har ett maxium för ett mellanvärde hos nettoproduktionen vid ESS.

Orientador: Guilherme de Paula Nogueira / Banca: José Luis Moraes Vasconcelos / Banca: Ciro Moraes Barros / Resumo: Seis novilhas Nelore tiveram seus ciclos estrais acompanhados durante diferentes estações do ano (outono n=11; inverno n=8; primavera n=9; verão n=9) com exames ultrassonográficos diários para contar e mensurar folículos ≥3mm. Amostras de sangue foram colhidas a cada 12h para hormônio luteinizante (LH) e progesterona (P4), e a cada 3h do estro até a ovulação para caracterizar o pico de LH. Cinco novilhas ovariectomizadas receberam 17β-estradiol (2μg/kg/p.v.) em cada estação, e amostras de sangue foram colhidas depois disso a cada 3h para quantificação de LH. A diferença percentual mensal ( %) do peso não variou entre as estações. A concentração média de P4 no ciclo estral foi maior (p=0,001) e o número de folículos menor (p=0,001) durante o outono (2,5±0,2ng/mL; 7,8±0,1) e verão (2,9±0,3ng/mL; 6,8±0,2) comparado com o inverno (1,4±0,2ng/mL; 9,6±0,3) e primavera (1,6±0,2ng/mL; 9,7±0,3). Durante o inverno houve mais ciclos estrais com três (5 de 8) e durante o verão somente ciclos com duas ondas foliculares (p=0,009). Como a secreção de LH não variou, apesar da variação sazonal na concentração de P4, e como houve correlação negativa entre os valores máximos de P4 e a variação percentual do fotoperíodo (p=0,0056; r = -0,4465), uma variação sazonal na sensibilidade das células luteínicas ao LH precisa ser avaliada. Nas novilhas ovariectomizadas, a concentração circanual de LH sem o estímulo de estradiol foi significante (p=0,0214). A resposta de LH ao tratamento de estradiol foi menor no verão (0,8±0,2ng/mL vs 1,3±0,5ng/mL). Nós supomos que existe variação sazonal na sensibilidade hipotalâmica ao estradiol. / Abstract: Six Nelore heifers had their estrous cycle followed during different seasons of the year (autumn n=11; winter n=8; spring n=9 and summer n=9) with daily ultrasonographic exams to count and measure follicles ≥3mm. Blood was collected every 12h for luteinizing hormone (LH) and progesterone (P4), and every 3h from estrus until ovulation to characterize the LH peak. Five ovariectomized heifers were injected with 17β-estradiol (2μg/kg/LW) every season and blood samples were collected thereafter at 3h intervals for LH quantification. The monthly body weight percentile difference ( %) did not vary between seasons. Average P4 concentration for the cycle was higher (p=0.001) and follicle number lower during autumn (2.5±.2ng/ml; 7.8±.1) and summer (2.9±.3ng/ml; 6.8±.2) (p=0.001) compared to winter (1.4±.2ng/ml; 9.6±.3) and spring (1.6±.2ng/ml; 9.7±.3). During winter there were more estrous cycles with three follicle waves (5 out of 8) and during summer only cycles with two follicular waves (p=0.009). As LH secretion did not vary despite seasonal variation in P4 concentration and as there was a negative correlation between higher P4 values and daily percentile variation of photoperiod ( %, p=0.0056; r= -0.4465), a seasonal variation in luteal cell sensitivity to LH needs to be evaluated. In the ovariectomized Nelore heifers, the LH circanual concentration without estradiol stimulus was significant (p=0.0214). The LH response to estradiol treatment was lower in summer (0.8±.2ng/ml vs 1.3±.5ng/ml). We hypothesize there exists seasonal variation in hypothalamic sensitivity to estradiol. / Mestre