No description available.

Despite our intuition, birds are no smaller than mammals when the constraints of a flying body plan are taken into account. Nevertheless, the largest mammals are ten times the mass of the largest birds. Allometric equations generated for anseriforms and ratites suggest mid-shaft femur circumference is the best measure to use in estimating avian body mass. The small sample size of extant ratites makes mass estimate extrapolation to larger extinct species inaccurate. The division of ratites into cursorial and graviportal groups is supported. Aepyornithids do not show atypical femoral shaft asymmetry. New and more accurate estimates of egg masses, and separate male and female body masses for sexually-dimorphic ratites are generated. Egg mass scaling exponents for individual bird orders differ from that Aves as a whole, probably due to between-taxa effects. Ratite egg mass does not scale with the same exponent as other avian orders, whether kiwi are included or excluded. Total clutch mass in ratites, however, scales similarly to egg mass in other birds, perhaps as a consequence of the extreme variation in ratite clutch size. Kiwi and elephant bird eggs are consistent with the allometric trend for ratites as a whole, taking clutch size into account. Thus kiwi egg mass is probably an adaptation for a precocial life history, not a side effect of their being a dwarfed descendant of a moa-sized ancestor. Relatively small body size in ancestral kiwis is consistent with a trans-oceanic dispersal to New Zealand in the Tertiary, as suggested by recent molecular trees. This implies multiple loss of flight in Tertiary ratite lineages, which is supported by biogeographic, molecular, paleontological, and osteological evidence, but which is not the currently prevailing hypothesis. / Dissertation

No description available.

No description available.

Mitochondrial content, an important determinant of muscle metabolic capacity, changes in individuals during development, and in response to physiological and environmental challenges. This phenotypic plasticity is attributed to the coactivator PPARγ coactivator-1α (PGC-1α) but it remains unclear if this transcriptional regulator accounts for evolutionary variation in mitochondrial content. In an attempt to explain why some species have higher muscle mitochondrial enzyme levels than other species, I examined if the transcriptional mechanisms that control mitochondrial content of a tissue in an individual are also responsible for differences between species. If PGC-1α creates differences between the mitochondrial content of species based on variation in promoter binding motifs, then cis-factor evolution may be the guiding force in scaling trends. In this thesis I explored the basis of size-dependent patterns by looking at layers of regulation, from catalytic activities to promoter evolution and regulation. A representative family, Rodentia, was used to collect muscle samples from a size range of approximately 20g up to 17 kg. As expected, in rodent lower limb muscles, mitochondrial and glycolytic enzyme activity exhibited reciprocal scaling patterns, though the scope differed between muscles. Very little of the variation was accounted for when the activity was related to DNA content. However, when COX activities were expressed relative to DNA, the scaling patterns were similar among the 3 muscles. To determine if interspecies differences were linked to transcriptional regulation, ~800bp of the PGC-1α promoter from 56 terrestrial mammals (5g-5000kg) was examined. The basal placental mammalian promoter possesses putative elements for Sp1, HNF3, myogenic factors and metabolic effectors, which have been retained in mammals with little change in order or spacing. To investigate the ability of these promoters to control PGC-1α expression, rodent promoters were cloned into luciferase reporter gene constructs and transfected into a common mouse myoblast background (Sol8 cells). Unlike mitochondrial content, promoter activity did not vary with body size across the rodent family. Likewise, PGC-1α transcript levels did not vary in rodent muscles in a way that would explain differences in COX activity. This suggests that though PGC-1α may be crucial for within species variation, transcriptional regulation of PGC-1α is not responsible for interspecies variation in mitochondrial content. / Thesis (Master, Biology) -- Queen's University, 2010-06-09 10:50:02.133

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-10-04Bitstream added on 2014-06-13T19:23:39Z : No. of bitstreams: 1 yanez_ea_dr_jabo.pdf: 472965 bytes, checksum: 1e3d450b0ba9483da550c43e4a8cf69f (MD5) / Foram realizados dois experimentos utilizando cabritos machos da raça Saanen. O primeiro teve por objetivo avaliar o desenvolvimento relativo dos componentes do peso vivo (PV), dos cortes comerciais e dos tecidos de caprinos leiteiros em crescimento. Tomando como referência o corte perna, o tecido ósseo apresentou crescimento precoce, o muscular isométrico e o adiposo crescimento tardio, sendo a gordura subcutânea depositada mais tardiamente. Os cortes comerciais apresentaram coeficiente de alometria isogônico com exceção dos cortes 6a a 13a costelas e peito/fralda. O desenvolvimento da carcaça e dos não-componentes da carcaça acompanhou o peso de corpo vazio, enquanto que a pele e cabeça+patas apresentaram coeficiente heterogônico negativo e o trato digestório coeficiente isogônico. Os cabritos com 35 kg de PV e 15,5 kg de carcaça apresentaram adequadas proporção de músculo e relação músculo:osso, mas maior proporção de gordura que os animais abatidos com 20 kg de PV. O segundo experimento foi desenvolvido em duas fases (5 a 20 e 20 a 35 kg de PV) e teve por objetivo avaliar os efeitos da restrição alimentar sobre as características da carcaça, e estimar equações para predizer características da carcaça a partir de medidas biométricas. Foram determinadas as medidas biométricas e a condição corporal nos animais vivos, e após o abate e resfriamento de 24 h, as medidas e compacidade da carcaça. As carcaças foram seccionadas em sete cortes e a perna dissecada em osso, músculo e gordura. O aumento da restrição alimentar produziu diminuição na proporção do lombo e aumento na do pescoço, na Fase 1. Na Fase 2 o lombo e 6a a 13a costelas diminuíram sua participação com o aumento da restrição e a paleta e o pescoço aumentaram. A proporção de ossos aumentou e a de gordura total diminuiu com o aumento da restrição nas duas fases... / Two experiments were developed with male Saanen kids. The objective of the first was to evaluate the relative development of the live weight components, of the commercials joints and of the kids dairy goat at growing tissues. The bones showed earlier development, the muscle was isometric and the fat later developing, but the subcutaneous fat was later developing than intermuscular fat. The commercials joints exhibited isogonic allometric coefficient with except of the 6a to 13a ribs and brisket. The development of the carcass and non-carcasses components followed the empty body weight, but the skin and head+paw showed earlier development and the gastrintestinal tract showed isometric coefficient. The kids goat with 35 kg LW and 15,5 kg of the carcass exhibited adequate muscles proportion and muscle:bone rate, but with higher fat rate than animals slaughter with 20 kg LW. The second experiment was developed in two phases (5 to 20 and 20 to 35 kg LW) and the objective was to evaluate the feed restriction effects in the carcass characteristics, and to estimate the equation that was allowed predict the characteristics of the carcass from the biometrics measures. It were determinated the biometrics measures and the corporal condition in the live animals, and after of the slaughter and chilling at 24 h, it were established the measures and compactness of the carcass. The carcasses were sectioned in seven commercials joints and the leg dissected in bone, muscle and fat. The increase of the feed restriction provide decrease in the loin proportion and the neck increase, of the Phase 1. On the Phase 2, the loin and the 6a to 13a ribs decreased their participation with the increase of the restriction and the shoulder and the neck increased. The proportion of the bones increased and the total fat decrease due high feed restriction in both phases... (Complete abstract, access undermentioned eletronic address)

Background. Allometric scaling (AS) is widely used in predicting human clearance (CL) based on animal data. Substantial prediction errors have been commonly observed and various modifications to AS have not provided a broad reliable improvement. In this study, an extensive data set was assembled including animal and human systemic CL and physiochemical properties. The allometric exponents were calculated based on multiple species AS and single-species AS methods. The correlations between the allometic exponents and physiochemical properties were evaluated in an attempt to find covariates that may explain the inter-compound variability in the allometric exponents. Lastly, the statistical approaches in analyzing the allometric function were evaluated with the collected data. Methods. 1- A nonlinear mixed effect modeling (MEM) approach was performed to investigate the central tendency and distribution of AS exponents as well as to identify whether there are any correlations between the allometric exponent, and coefficient, with the physicochemical and drug metabolism and pharmacokinetics (DMPK) properties of the compounds. 2- Single-species AS was performed to estimate the single-species AS exponent distributions and their corresponding central tendencies. The correlation between the estimated single-species AS exponents and the physicochemical and DMPK properties of the compounds were also examined. 3- The methodologies of log-log transformation followed by linear regression (LL-LR) and direct nonlinear regression methods (NLS) with different weighting schemes on the AS power function were investigated. The central tendency and distribution of the allometric exponents were evaluated and compared across methods. Furthermore, the human CL prediction performance was evaluated among methods. Results. The estimated central tendency and distribution of AS exponents from the nonlinear MEM as well as the single-species AS approaches were consistent with literature reports. There were no significant correlations identified between the estimated AS exponents and the physicochemical or DMPK properties. The methods of LL-LR and the NLS with 1/w2 weighting (variance weighted by CL2 during the variance minimization process) results in the most similar allometric exponent with central tendency around 0.668 and provided the best human CL prediction among methods investigated. Conclusion. The knowledge gained in this work by extensive modeling and simulations contributed to a better understanding of the variability in AS exponents and better practice in performing AS in human CL prediction

This thesis is an investigation of barrenness and plant-to-plant variability (PPV) in ear development of maize (Zea mays L.). A three-year field experiment was conducted on homogenous plants with similar initial plant size, development and uniform spatial patterns in parental inbred lines CG60, CG102 and their F1 hybrid CG60 × CG102. Physiological processes underlying barrenness were dissected into plant growth through development and dry matter partitioning to the ear at canopy, subpopulation, and primarily, individual plant levels. The growth and development of the ultimately barren individuals were followed from early vegetative stage to physiological maturity (PM) using a non-destructive allometric methodology. Plant-to-plant variability in ear development, related to plant development, was measured destructively from ear initiation to 1 wk after silking and at PM. Results showed that the individual plants exhibited differential responses to their previous growth and development in the two parental inbred lines. No physiological traits in growth and development or dry matter partitioning to the ear during the critical period bracketing silking could characterize individual barren plants. The F1 hybrid was resistant to barrenness even at 160,000 plants ha-1. At 80,000 plants ha-1, the spikelet number per row (SNPR) and spikelet number per ear (SNPE) exhibited less PPV around silking than earlier stages of development. For the three genotypes, PPV in plant morphological traits and ear length was relatively constant throughout development. In addition, the period around the kernel row number (KRN) formation stage was the only time-window that the PPV in stem volume, representing PPV in above-ground plant dry matter (PDM), affected PPV in SNPR and KRN for the three genotypes, with SNPR being more affected. Although the F1 produced greater PDM at silking and 1 wk after silking, it had shorter ear length and less ear dry matter than the two parental inbred lines at the corresponding stages. When the relationships are elucidated among early ear development, plant growth, leaftip development, and dry matter partitioning to the ear, during the vegetative to silking stages and under stress conditions, then the physiological processes underlying barrenness of the tested inbred lines could be further characterized. / Syngenta, the Ontario Research Fund, the Ontario Ministry of Agriculture, Food and Rural Affairs, and the Natural Sciences and Engineering Research Council of Canada

Orientador: Kleber Tomás de Resende / Banca: Juan Ramón Olalquiaga Perez / Banca: Silvio Doria de Almeida Ribeiro / Banca: Heraldo Cesar Gonçalves / Banca: Silvana Martinez Baraldi Artoni / Resumo: Foram realizados dois experimentos utilizando cabritos machos da raça Saanen. O primeiro teve por objetivo avaliar o desenvolvimento relativo dos componentes do peso vivo (PV), dos cortes comerciais e dos tecidos de caprinos leiteiros em crescimento. Tomando como referência o corte perna, o tecido ósseo apresentou crescimento precoce, o muscular isométrico e o adiposo crescimento tardio, sendo a gordura subcutânea depositada mais tardiamente. Os cortes comerciais apresentaram coeficiente de alometria isogônico com exceção dos cortes 6a a 13a costelas e peito/fralda. O desenvolvimento da carcaça e dos não-componentes da carcaça acompanhou o peso de corpo vazio, enquanto que a pele e cabeça+patas apresentaram coeficiente heterogônico negativo e o trato digestório coeficiente isogônico. Os cabritos com 35 kg de PV e 15,5 kg de carcaça apresentaram adequadas proporção de músculo e relação músculo:osso, mas maior proporção de gordura que os animais abatidos com 20 kg de PV. O segundo experimento foi desenvolvido em duas fases (5 a 20 e 20 a 35 kg de PV) e teve por objetivo avaliar os efeitos da restrição alimentar sobre as características da carcaça, e estimar equações para predizer características da carcaça a partir de medidas biométricas. Foram determinadas as medidas biométricas e a condição corporal nos animais vivos, e após o abate e resfriamento de 24 h, as medidas e compacidade da carcaça. As carcaças foram seccionadas em sete cortes e a perna dissecada em osso, músculo e gordura. O aumento da restrição alimentar produziu diminuição na proporção do lombo e aumento na do pescoço, na Fase 1. Na Fase 2 o lombo e 6a a 13a costelas diminuíram sua participação com o aumento da restrição e a paleta e o pescoço aumentaram. A proporção de ossos aumentou e a de gordura total diminuiu com o aumento da restrição nas duas fases... (Resumo completo, clicar no acesso eletrônico abaixo) / Abstract: Two experiments were developed with male Saanen kids. The objective of the first was to evaluate the relative development of the live weight components, of the commercials joints and of the kids dairy goat at growing tissues. The bones showed earlier development, the muscle was isometric and the fat later developing, but the subcutaneous fat was later developing than intermuscular fat. The commercials joints exhibited isogonic allometric coefficient with except of the 6a to 13a ribs and brisket. The development of the carcass and non-carcasses components followed the empty body weight, but the skin and head+paw showed earlier development and the gastrintestinal tract showed isometric coefficient. The kids goat with 35 kg LW and 15,5 kg of the carcass exhibited adequate muscles proportion and muscle:bone rate, but with higher fat rate than animals slaughter with 20 kg LW. The second experiment was developed in two phases (5 to 20 and 20 to 35 kg LW) and the objective was to evaluate the feed restriction effects in the carcass characteristics, and to estimate the equation that was allowed predict the characteristics of the carcass from the biometrics measures. It were determinated the biometrics measures and the corporal condition in the live animals, and after of the slaughter and chilling at 24 h, it were established the measures and compactness of the carcass. The carcasses were sectioned in seven commercials joints and the leg dissected in bone, muscle and fat. The increase of the feed restriction provide decrease in the loin proportion and the neck increase, of the Phase 1. On the Phase 2, the loin and the 6a to 13a ribs decreased their participation with the increase of the restriction and the shoulder and the neck increased. The proportion of the bones increased and the total fat decrease due high feed restriction in both phases... (Complete abstract, access undermentioned eletronic address) / Doutor

Destructive sampling of 20 trees of four tree species in a mixed New England conifer/hardwood stand shows that leaf area comprises 72, 77, and 78 percent of plant area as measured with digital hemispherical photography of the stand in (1) leaf-off, (2) leaf-out and pre-harvest, and (3) leaf-out and post-harvest conditions. Leaf area index values for the stand, estimated through destructive sampling, were 4.42, 5.98, and 5.08 respectively, documenting the progression of leaf growth through post-harvest. Terrestrial lidar scans (TLS) of the stand in (1) leaf-off and (2) leaf-out and pre-harvest conditions provided leaf area index values of 4.49 and 6.00 using the correction applied to observed plant area index, showing good agreement. The method relies on destructive sampling to relate the weight of foliage removed from sample trees to leaf area and fine twig area within the foliage as measured by a flatbed scanner. Two conifer species, eastern hemlock and white pine, and two deciduous species, red maple and red oak, in five diameter-size classes, were harvested from the 50 x 50-m stand in late summer. Leaf and twig areas of these trees provided species-specific allometric equations relating stem basal area to leaf and twig area, and a stand map provided species, counts and diameters of all trees in the plot. These data then allowed estimation of the leaf area of the stand as a whole for comparison with optical methods. The ratios of leaf to fine-branch area for each species vary, with values of 5.33, 25.38, 260.88 and 140.35 for eastern hemlock, white pine, red maple, and red oak respectively. This variance shows that woody-to-total area constants, which are used for calculating leaf area index from plant area index values determined by optical gap probability methods, will be quite dependent on stand composition and questions the common usage of literature constants for this purpose. This study shows how destructive sampling can lead to better estimation of forest leaf area index and wood area index from hemispherical photography and terrestrial lidar scanning, which has the potential to improve modeling of nutrient cycling and carbon balance in ecosystem models.