No description available.

Scottish red deer (Cervus elaphus scoticus) are smaller in size and mature later than many continental subspecies. Previous investigations at the Rowett Institute have shown that when Scottish red deer are fed well they grow almost as large as European deer, so the differences between subspecies appear principally determined by the environment. To test this, one group of 6 stag calves was fed to appetite while a second group of 6 was offered 70% as much (on a metabolic body weight basis) during the winter and both groups fed to appetite during the following summer. After the first winter the restricted group were lighter and skeletally smaller than the unrestricted group. Despite compensatory growth during the summer significant differences in weight and size remained at the end of the period of feeding to appetite. This pattern was repeated during the second and third years of the study, Plane of nutrition bad little effect on size and composition of antlers but had profound effects on the timing of growth of the first antlers. Although the restricted stags were less fat than the unrestricted stags both groups showed the same relationship of fat content of the body to empty body weight. The restricted plane of nutrition delayed the growth and moult of wool and hair but did not affect length of either. The restricted plane of nutrition exerted only slight effects on levels of testosterone, oestradiol 17 beta,prolaotin and thyroriue and no effect on the timing of their cycles. A field study on the effect of winter undernutrition on stag calves at Glensaugh Deer Farm gave similar results. Cycles of body weight and food intake were shown to be of smalleramplitude in captive hinds than stage. Superior cervical ganglioneotomy of Soay rams diminished the amplitude of cycles of food intake and growth as much as cycles of reproduction but failed to abolish either.

Photoperiod is an important signal involved in the timing and co-ordination of many processes such as growth and reproduction in salmonids. Both growth and reproduction appear to be controlled by endogenous rhythms, which under natural conditions, is entrained by the seasonal changes in daylength, that is accurately reflected by the diel pattern of melatonin. This thesis investigates the influence of photoperiod on growth and reproduction in rainbow trout (Oncorhynchus mykiss), and examines the effect on plasma insulin-like growth factor-I (IGF-I). These studies aim to further our scientific understanding of the endocrine mechanisms controlling growth and reproduction and transfer this knowledge to commercial trout farming practices. Studies at fry (<5g) and fingerling (>25g) stages investigated the effect of exposure to constant long-days (LD18:6) and constant light (LL) on growth performance. In all experiments, there was a significant growth enhancing effect following exposure to extended light regimes relative to those under ambient or constant short-day photoperiods. Growth enhancement appeared to be caused through direct photo-stimulation or a phaseshift in an underlying endogenous rhythm dependent on the timing of photoperiod application. Measurement of plasma IGF-I accurately reflected growth rate during juvenile development. Furthermore, a clear autumnal increase in IGF-I was observed that was apparently up-regulated by long-day photoperiods. Additionally, it was shown that melatonin implants significantly reduced growth rate below that of unimplanted controls irrespective of photoperiod, but did not reduce circulating IGF-I levels suggesting that elevated melatonin levels masked the perception of daylength but did not act directly on the somatotropic axis to control growth. As size or one of its correlates (growth rate, energy balance or nutritional status) is regarded as an important determinant of the ability to undergo puberty, the interaction of natural (SNP) and advancing (ADV: long-short day) photoperiods with growth, IGF-I and reproduction was investigated in virgin female broodstock. Under SNP 63% of the population attained maturity while only 29% spawned in the ADV regime. Under SNP both size and growth rate in late spring/early summer appeared to determine whether an individual may initiate maturation. Conversely, under ADV, condition factor appeared to be a better predictor. A complete seasonal relationship between plasma IGF-I, daylength and temperature was demonstrated for the first time in rainbow trout under natural conditions, and provides direct evidence for the relationship between maturation and IGF-I. IGF-I levels showed a negative correlation with testosterone as fish initiated maturation. Furthermore, IGF-I levels accurately reflected growth rate prior to the initiation of vitellogenesis, suggesting that IGF-I may provide an endocrine signal between the somatotropic and reproductive axes that nutritional status, growth rate and/or size is sufficient to initiate maturation. In addition, maturing individuals under both photoperiods typically expressed higher circulating IGF-I levels than those that remained immature and may reflect a greater opportunity for IGF-I to act on the pituitary to stimulate gonadotropin production. In this sense, the observation of elevated levels for 3 months under SNP compared to only 1 month under ADV may reflect a reduction in the window of opportunity to initiate maturation under advancing photoperiods and hence explain the reduction in fish spawning. Finally, using a commercially available ELISA kit provided evidence of a possible detection method for measurement of a leptin-like peptide as absolute levels differed significantly between mature and immature fish. This provides preliminary evidence for a possible involvement of a leptin-like peptide in rainbow trout reproduction and energy homeostasis. Given the above evidence of a growth enhancing effect of photoperiod in covered systems, the transfer of constant light (LL) regimes to uncovered commercial trout farming practices was also examined. The application of LL regimes during either fry grow-out in tanks using floating lights or ongrowing to harvest size during winter in cages using submersible lights was investigated. In all trials conducted, the exposure to LL in autumn significantly enhanced winter growth rate and feeding efficiency by up to 30% and 25% respectively relative to those maintained under ambient light. Furthermore, the effect of light intensity was clearly shown to be an important requirement in successfully applying photoperiod regimes onto the ambient photoperiod in order to enhance commercial production in "uncovered systems". These studies clearly indicate the importance of photoperiod in influencing growth and reproduction in rainbow trout. Furthermore, the use of plasma IGF-I as an indicator of growth provides a practical tool for studying growth-photoperiod-reproduction interactions in this species. However, further studies are necessary to further our understanding of the endocrine pathways governing physiological mechanisms, especially growth and reproduction. Overall, this work has provided important information to improve both scientific understanding and commercial development although it is clear that substantial research is still required.

No description available.

Thesis (M. Sc.)--University of Adelaide, 1988. / Includes bibliographical references (leaves 131-150).

Thesis (Ph.D.) -- Mississippi State University. Department of Plant and Soil Sciences. / Title from title screen. Includes bibliographical references.

A Artemisia annua L. (Asteraceae) é uma planta herbácea, nativa da Ásia e aclimatada no Brasil. As folhas apresentam até 1,4% do peso seco em artemisinina, sendo fonte abundante desta lactona sesquiterpênica que, conjuntamente aos seus derivados semi-sintéticos, apresentam ação efetiva contra as cepas resistentes das espécies de Plasmodium causadoras da malária. A artemisinina também está sendo testada com sucesso no tratamento de câncer e apresenta-se efetiva contra inúmeros parasitas que afetam a saúde humana e animal. Os objetivos deste trabalho foram determinar as épocas de plantio e colheita da cultivar Artemis de A. annua em Pato Branco-PR, como também, determinar em campo o fotoperíodo crítico e o número de ciclos fotoindutivos necessários para o florescimento desta cultivar. Um segundo experimento foi realizado com o objetivo de determinar o potencial alelopático desta espécie sobre sementes de alface e leiteiro. No experimento em campo, os tratamentos utilizados foram seis diferentes épocas de plantio, sendo as 09 plantas centrais das parcelas colhidas para a determinação da massa seca de folha e caules, relação folha/caule e teor de artemisinina na massa seca de folhas quando 50% das plantas da parcela iniciaram a emissão dos botões florais. O número de ciclos fotoindutivos encontrado para a cultivar Artemis foi de aproximadamente 36 ciclos e o fotoperíodo crítico aproximado foi de 13 horas, que ocorreu em 09/02/2007 em Pato Branco-PR. Esse resultado determinou que a época de colheita para a cultivar Artemis, na região de Pato Branco-PR, deve ser na segunda quinzena do mês de março. O maior rendimento de biomassa nesse experimento ocorreu no plantio de 27/07/2007, 231 dias após o transplantio, mas recomenda-se tomar cuidado com as geadas que podem ocorrer até a primeira quinzena de setembro, sugerindo-se optar pelo plantio na segunda quinzena de setembro, período livre de geadas na região. Os maiores teores de artemisinina (em média 0,80% na matéria seca de folhas) foram obtidos nas épocas que mais vegetaram a campo devido à maior produção de biomassa. Para o experimento de alelopatia, o extrato aquoso bruto foi preparado a partir de folhas frescas na proporção de 1 L de água destilada para 250 g do material. Foram utilizadas as seguintes concentrações do extrato aquoso: 100%, 75%, 50%, 25% e 0% (água destilada). Foram analisadas as variáveis germinabilidade, velocidade média de germinação, tempo médio de germinação, comprimento da radícula e massa seca das plântulas. Extratos aquosos de A. annua apresentaram ação alelopática inibitória sobre a germinação de sementes e o desenvolvimento de plântulas de alface e leiteiro. / The Artemisia annua L. (Asteraceae) is a herbaceous plant, native of Asia and acclimated in Brazil. The leaves are abundant source of artemisinin, a sesquiterpene lactone that, jointly to yours derived semi-synthetic, they present effectiveness action against the resistant stumps of the species of Plasmodium against malaria. The artemisinin is also being tested with success in the cancer treatment and against countless parasites that affect the human and animal health. The objectives of this work went to determine the planting times and crop of the cultivar Artemis of A. annua in Pato Branco-PR, as well as, to determine in field the critical photoperiod and the number of inductive photoperiod for the flowering of this cultivar. A second experiment was accomplished with the objective of determining the allellopathic effect of this species on lettuce seeds and wild poinsettia. In the experiment in field, the treatments were six different transplant times, being the 09 central plants of the portions picked for the determination of the mass dries of leaf and stems, relationship leaf/stems and artemisinin in the mass dries of leaves when 50% of the plants of the portion began the emission of the floral buttons. The number of cycles inductive found for the cultivar Artemis was of approximately 36 cycles and the critical photoperiod was approximately 13 hours, that happened in 09/02/2007 in Pato Branco-PR. This results determines that the crop time for cultivar Artemis, in Pato Branco-PR will be in the second fortnight of the month of March. The largest biomass income in that experiment happened in the planting of 27/07/2007, 231 days after the transplant, but it is recommended to take care with the frost that can happen until the first fortnight of September, suggesting choose for the transplant in the second fortnight of September, period free from frost in the area. The largest artemisinin tenor (0,88% in dry matter leaves) was obtained in the times that more they vegetated to field due to the largest biomass production. Besides this experiment, a second experiment was developed to determine the allellopathic effects of this species on lettuce seeds and wild poinsetia. The aqueous extract was prepared starting from fresh leaves in the proportion of 1 L of water distilled for 250 g of the material, after, the extract was filtrate and centrifuged, being used the sobrenadante. The following concentrations of the extract were used: 100%, 75%, 50%, 25% and 0% (distilled water). They were analyzed the variables germinability, germination velocity, germination time, length of the radicle and weight of the dry matter of the seedlings. Aqueous extracts of A. annua is allellopathic on the germination and development of lettuce and wild poinsettia seedlings.

A Artemisia annua L. (Asteraceae) é uma planta herbácea, nativa da Ásia e aclimatada no Brasil. As folhas apresentam até 1,4% do peso seco em artemisinina, sendo fonte abundante desta lactona sesquiterpênica que, conjuntamente aos seus derivados semi-sintéticos, apresentam ação efetiva contra as cepas resistentes das espécies de Plasmodium causadoras da malária. A artemisinina também está sendo testada com sucesso no tratamento de câncer e apresenta-se efetiva contra inúmeros parasitas que afetam a saúde humana e animal. Os objetivos deste trabalho foram determinar as épocas de plantio e colheita da cultivar Artemis de A. annua em Pato Branco-PR, como também, determinar em campo o fotoperíodo crítico e o número de ciclos fotoindutivos necessários para o florescimento desta cultivar. Um segundo experimento foi realizado com o objetivo de determinar o potencial alelopático desta espécie sobre sementes de alface e leiteiro. No experimento em campo, os tratamentos utilizados foram seis diferentes épocas de plantio, sendo as 09 plantas centrais das parcelas colhidas para a determinação da massa seca de folha e caules, relação folha/caule e teor de artemisinina na massa seca de folhas quando 50% das plantas da parcela iniciaram a emissão dos botões florais. O número de ciclos fotoindutivos encontrado para a cultivar Artemis foi de aproximadamente 36 ciclos e o fotoperíodo crítico aproximado foi de 13 horas, que ocorreu em 09/02/2007 em Pato Branco-PR. Esse resultado determinou que a época de colheita para a cultivar Artemis, na região de Pato Branco-PR, deve ser na segunda quinzena do mês de março. O maior rendimento de biomassa nesse experimento ocorreu no plantio de 27/07/2007, 231 dias após o transplantio, mas recomenda-se tomar cuidado com as geadas que podem ocorrer até a primeira quinzena de setembro, sugerindo-se optar pelo plantio na segunda quinzena de setembro, período livre de geadas na região. Os maiores teores de artemisinina (em média 0,80% na matéria seca de folhas) foram obtidos nas épocas que mais vegetaram a campo devido à maior produção de biomassa. Para o experimento de alelopatia, o extrato aquoso bruto foi preparado a partir de folhas frescas na proporção de 1 L de água destilada para 250 g do material. Foram utilizadas as seguintes concentrações do extrato aquoso: 100%, 75%, 50%, 25% e 0% (água destilada). Foram analisadas as variáveis germinabilidade, velocidade média de germinação, tempo médio de germinação, comprimento da radícula e massa seca das plântulas. Extratos aquosos de A. annua apresentaram ação alelopática inibitória sobre a germinação de sementes e o desenvolvimento de plântulas de alface e leiteiro. / The Artemisia annua L. (Asteraceae) is a herbaceous plant, native of Asia and acclimated in Brazil. The leaves are abundant source of artemisinin, a sesquiterpene lactone that, jointly to yours derived semi-synthetic, they present effectiveness action against the resistant stumps of the species of Plasmodium against malaria. The artemisinin is also being tested with success in the cancer treatment and against countless parasites that affect the human and animal health. The objectives of this work went to determine the planting times and crop of the cultivar Artemis of A. annua in Pato Branco-PR, as well as, to determine in field the critical photoperiod and the number of inductive photoperiod for the flowering of this cultivar. A second experiment was accomplished with the objective of determining the allellopathic effect of this species on lettuce seeds and wild poinsettia. In the experiment in field, the treatments were six different transplant times, being the 09 central plants of the portions picked for the determination of the mass dries of leaf and stems, relationship leaf/stems and artemisinin in the mass dries of leaves when 50% of the plants of the portion began the emission of the floral buttons. The number of cycles inductive found for the cultivar Artemis was of approximately 36 cycles and the critical photoperiod was approximately 13 hours, that happened in 09/02/2007 in Pato Branco-PR. This results determines that the crop time for cultivar Artemis, in Pato Branco-PR will be in the second fortnight of the month of March. The largest biomass income in that experiment happened in the planting of 27/07/2007, 231 days after the transplant, but it is recommended to take care with the frost that can happen until the first fortnight of September, suggesting choose for the transplant in the second fortnight of September, period free from frost in the area. The largest artemisinin tenor (0,88% in dry matter leaves) was obtained in the times that more they vegetated to field due to the largest biomass production. Besides this experiment, a second experiment was developed to determine the allellopathic effects of this species on lettuce seeds and wild poinsetia. The aqueous extract was prepared starting from fresh leaves in the proportion of 1 L of water distilled for 250 g of the material, after, the extract was filtrate and centrifuged, being used the sobrenadante. The following concentrations of the extract were used: 100%, 75%, 50%, 25% and 0% (distilled water). They were analyzed the variables germinability, germination velocity, germination time, length of the radicle and weight of the dry matter of the seedlings. Aqueous extracts of A. annua is allellopathic on the germination and development of lettuce and wild poinsettia seedlings.

Male ring doves ( Streptopelia risoria ) held on long days perform more nest-building than birds held on short days. This difference persists even if circulating androgen is maintained at similar levels in both groups by castration and treatment with exogenous testosterone. It therefore appears that daylength can alter nest-building through some means other than changes in gonadal androgen production. The experiments described in this thesis examined three mechanisms which might be responsible for the effect of daylength on male nest-building. The first series of experiments tested the hypothesis that nest-building activity is greater under long days as a result of increased aromatization of testosterone into estrogen. Castrated male doves were implanted with estradiol benzoate, testosterone propionate (TP), or a combination of TP and an aromatase inhibitor, ATD, and exposed to either long or short photoperiods. Males held under long days continued to build more actively, regardless of the type of hormone being used. The results thus indicate that differences in the rate of aromatization cannot account for the effect of photoperiod. In a second series of experiments an attempt was made to determine whether an increase in the production of hypothalamic luteinizing hormone releasing hormone (LHRH) under long daylengths stimulates nest-building, as a result of a synergism with testosterone. Long- and short-day castrated males were treated with exogenous TP or TP and LHRH to see if the influence of short daylengths could be reversed by LHRH. LHRH treatment had no effect on the nesting activity of either short- or long-day birds. Finally, several tests were performed which focussed on the role of the pineal gland. Removal of the pineal caused a decrease in nesting activity in long-day birds, but not in short-day birds. The effect of pinealectomy does not depend on the presence of the gonads, since the birds displayed similar responses following castration and testosterone treatment. In the second test, the ability, of pinealectomy to nullify the stimulatory influence of long daylengths was confirmed. In addition, injections of chicken pineal extract increased nest-building in pinealectomized and in short-day pineal-intact birds, suggesting that the pineal produces a substance which is capable of stimulating nesting activity. The identity of this substance is unknown. Pilot tests using melatonin failed to show any stimulatory effect of this compound on nesting behaviour. However, serotonin, which is also present in the pineal in high concentration, did increase nest-building in short-day pinealectomized males. These results indicate that in response to long daylengths the pineal gland of male doves releases a compound, possibly serotonin, which stimulates nest-building activity. / Science, Faculty of / Zoology, Department of / Graduate

Orientador: Lilian Beatriz Penteado Zaidan / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T09:17:44Z (GMT). No. of bitstreams: 1 Rondon_JosimaraNolasco_D.pdf: 1536546 bytes, checksum: 297d7328b9b2a132fca75bfad73844c8 (MD5) Previous issue date: 2006 / Resumo: Uma população de Bauhinia holophylla Steud. localizada no cerrado sensu stricto da Reserva Biológica e Estação Experimental de Moji Guaçu (RBEE de Moji Guaçu) foi estudada quanto a sua fenologia reprodutiva, expectativa de vida foliar, predação de sementes, germinação, fotoperíodo e regeneração natural. O padrão de distribuição da população adulta e jovem de B. holophylla, na área estudada é do tipo agregado. A população jovem e adulta de B. holophylla na RBEE de Moji Guaçu pode ser considerada juvenil, concentrando a maioria dos indivíduos nas primeiras classes de crescimento em altura e diâmetro. A expectativa média de vida da folha no primeiro ano de estudo foi de 8,2 meses, enquanto no segundo ano foi de 7,6 meses. A produtividade primária da fração folhas de 21 plantas de B. holophylla amostradas foi mais intensa nos meses de julho a agosto, durante o período de estudo (dois anos), portanto, durante a estação seca. A fração flores e botões esteve associada ao período da estação chuvosa, com produção maior nos meses de novembro a janeiro. A mortalidade foliar coincidiu com o período de menor precipitação na estação seca. A queda total das coortes foliares ocorreu ao mesmo tempo, na estação seca, estando a presença da folha durante a estação chuvosa, relacionada à produção de fotoassimilados para a planta, que serão usados na reprodução e/ou armazenados como amido no xilopódio. Plantas de B. holophylla apresentaram maior altura e diâmetro caulinar, e maior número de folhas nos tratamentos fotoperiódicos de 16 e 20 horas que nos tratamentos de 8 e 12 horas. A predação de sementes é uma das principais causas da inexistência de plântulas no cerrado. Contudo, a regeneração natural não está comprometida devido à presença do xilopódio. As sementes de B. holophylla são neutras à luz para a germinação e germinam em uma faixa ampla de temperatura. A permanência efêmera de sementes de B. holophylla no banco de sementes do solo de cerrado deve-se muito provavelmente à neutralidade à luz e velocidade de germinação alta em temperaturas na faixa de 25ºC a 30ºC. Práticas de manejo na RBEE de Moji Guaçu a partir do controle de larvas e de insetos predadores são fundamentais para aumentar a produção de sementes sadias de B. holophylla. Investigações sobre auto-ecologia, serapilheira, fenologia reprodutiva e dinâmica populacional devem ser propostas para espécies do Cerrado. Essas investigações podem auxiliar nos programas de recuperação de áreas remanescentes de cerrado e constituem modelos para estudos de populações de espécies vegetais do cerrado / Abstract: A population of Bauhinia holophylla located at a cerrado area in the Reserva Biológica e Estação Experimental de Moji Guaçu was studied in relation to reproductive phenology, leaf life span, seed predation, seed germination and aspects of plant regeneration. The distribution pattern of the juvenile and adult population is considered agregated. This population can be considered on the juvenile stage, due to, the greater number of plants concentrate in to the first size classes (height and diameter). The mean leaf life span was 8.2 months in the first year and 7.6 months in the second year. The primary productivity of leaves was more intense, during dry season (July-August). Leaf mortality with the period of the minor precipitation registered (dry season). Flower and bud production was associated to the wet season. Leaf fall ocurred during dry season. The new leaves could garantee the production of photoassimilates that would be utilized by all plant organs in their metabolic activities and as a reserve carbohydrate stored in the xylopodium as starch. Higher stems and stem diameter and leaf number in plants were observed in the photoper iodic treatments of 16h and 20 hours (long days) than in plants maintened in 8h and 12 hours (short days). Seeds predation is the principal cause of inexistence of seedlings in that the cerrado area. However, plant regeneration is provided by xylopodium. The seed is neutral to light for germination at the temperature range of 20ºC to 35ºC. Germination speed germination at 25ºC in the dark was higher than under light. The ephemeral permanence of the seeds of B. holophylla in the cerrado soil seed bank, is probably due to neutrality of light and their fast germination at 25ºC-30ºC. Thus, management polices at the Reserva Biológica e Estação Experimental de Moji Guaçu to decrease larvae and predator insects are fundamental to enlarge the production of healthy seeds of B. holophylla. Investigation on auto-ecology, litter and reproductive phenology, may give important information about of species occurring in the Cerrado. Investigations can support recuperation programmes of remnant cerrado areas and constitute model to study populations of plants species the Cerrado / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal