Despite increasing computer power, the requirement to upscale 3D geological models for dynamic reservoir simulation purposes is likely to remain in many commercial environments. This study established that there is a relationship between sandbody size, cell size and changes to predictions of reservoir production as grids are upscaled. The concept of a cell width to sandbody width ratio (CSWR) was developed to allow the comparison of changes in reservoir performance as grids are upscaled. A case study of the Flounder Field in the Gippsland Basin resulted in the interpretation of three depositional environments in the intra-Latrobe reservoir interval. The sandbody dimensions associated with these depositional environments were used to build a series of 3D geological models. These were upscaled vertically and horizontally to numerous grid cell sizes. Results from over 1400 dynamic models indicate that if the CSWR is kept below 0.3 there will be a strong correlation between the average production from the upscaled grids compared to those of a much finer grid, and there will be less than 10% variation in average total field production. If the CSWR is between 0.3 and 1, there could be up to 30% difference, and once the CSWR exceeds 1.0 there is only a weak relationship between the results from upscaled grids and those of finer grids. As grids are upscaled the morphology of bodies in facies models changes, the distribution of petrophysical properties is attenuated and the structure is smoothed. All these factors result in a simplification of the fluid flow pathways through a model. Significant loss of morphology occurs when cells are upscaled to more than a half the width of the reservoir body being modelled. A simple rule of thumb is established — if the geological features of a model cannot be recognised when looking at a layer in the upscaled grid, the properties of the upscaled grid are unlikely to be similar to those of the original grid and the predictions of dynamic models may vary significantly from those of a finer grid. This understanding of the influence of sandbody size on the behaviour of upscaled dynamic models can be used in the planning stages of a reservoir modelling project. Two simple charts have been created. The first chart is for calculating the approximate number of cells in a model before it is built. The second chart is for comparing the proposed cell size against the CWSR, so that the predicted discrepancy between the ultimate production from the upscaled grid and one with much smaller cells can be assessed. These two charts enhance discussion between all interested disciplines regarding the potential dimensions of both static and upscaled dynamic models during the planning stage of a modelling project, and how that may influence the results of dynamic modelling. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1375309 / Thesis (Ph.D.) - University of Adelaide, Australian School of Petroleum, 2009

Thesis (Ph.D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed on June 24, 2009). Includes bibliographical references.

In my thesis I present data collected from a long-term selection experiment using the freshwater model organism Chlamydomonas reinhardtii. The selection experiment was designed to disentangle the effects of the number of multiple environmental drivers (MEDs) and the identity of those environmental drivers including high CO2, high temperature, general nutrient depletion, reduced light intensity, reduced phosphate availability, the addition of a herbicide, UV radiation and reduced pH. Using up to eight environmental drivers, I show how simple organisms such as C. reinhardtii evolve in response to MEDs. The first step in this investigation is to examine the short-term response of MEDs. Data collected at the beginning of the selection experiment will provide insight into the early stages of microevolution by investigating key differences in the short-term (plastic) responses to few vs. many MEDs. Here, I focus on how the data collected from the responses to single environmental drivers can help us predict the responses to MEDs by using ecological models (additive, comparative, multiplicative). I show that the short-term plastic responses to single environmental drivers can predict the effect of MEDs using the comparative model because the response is largely driven by the single dominant driver present. I also demonstrate the importance of the number of environmental drivers (NED) for making predictions from the single environmental drivers and show that predictions become more reliable as the NED increases. The results gathered from short-term responses provide evidence that single environmental driver studies are useful for predicting the effect of MEDs. After evolution, I found that the strength of selection varies with NED in a predictable way, which connects the NED to the evolutionary response (size of the direct response) through the strength of selection. Here, I used statistical models to quantify the effect of NED on the evolutionary response to MEDs and then interpreted this by considering the possible genetic constraints on adaptation to MEDs. A subset of populations evolved in environments with five environmental drivers and all populations evolved in the single environmental driver environments are used to examine how adapting to single vs. many environmental drivers affect local adaptation. I examine how populations selected in environments with one environmental driver, five environmental drivers and the evolved control, differ in their response to new environments with the same NED, environments with different NED, and a novel environment. I found that there is a relationship between local adaptation and the strength of selection in the local environment and patterns of local adaptation are affected by the NED of new environments. Lastly, I present the phenotypic consequences of evolution under MEDs. I found that before evolution, measures of chlorophyll content and cell size decline with increasing NED. However, after evolution the relationship between chlorophyll content and cell size with NED is weaker because populations converge on the same phenotypes as they evolve. I also present a case-study of how mass spectrometry methods can be used to better understand underlying molecular mechanisms of two phenotypes (chlorophyll positive and chlorophyll negative cells). This selection experiment is a good example of how laboratory investigations and model organisms can be used to design experiments with enough replication to have high statistical power in order to make more accurate predictions on the short- long-term effects of MEDs. Whilst there have been some studies on the effects of MEDs, these studies rarely have more than three environmental drivers (sometimes 5 environmental drivers) and there are only a handful of long-term MED studies. This study can be used to develop a priori hypotheses for investigating how environmental change will shape natural microbial communities, and is especially useful for organisms where long-term studies with multiple environmental drivers are unfeasible.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-04-28T17:48:29Z No. of bitstreams: 2 Dissertação - Hugo José Ribeiro - 2015.pdf: 4005712 bytes, checksum: 3ca2bfd5ce9d093857a0f4a6501f84f1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-04-28T17:53:14Z (GMT) No. of bitstreams: 2 Dissertação - Hugo José Ribeiro - 2015.pdf: 4005712 bytes, checksum: 3ca2bfd5ce9d093857a0f4a6501f84f1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-28T17:53:14Z (GMT). No. of bitstreams: 2 Dissertação - Hugo José Ribeiro - 2015.pdf: 4005712 bytes, checksum: 3ca2bfd5ce9d093857a0f4a6501f84f1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the digital relief is best represented by the digital terrain model (DTM) and the automatic extraction from topographical parameters of this data type, configures a viable alternative in relation to the manual process performed on topographic maps. However, the available data may contain faults or present information to altitude that are not exactly the terrain. In this sense, it is important to consider these issues in the application of MDT. In hydrology, for example, you must perform preprocessing steps to eliminate inconsistencies that might prevent the natural reproduction of the flow of water toward the riverbeds. The objective of this research is to check the limits of applicability of the MDTs in hydrological analyses. For this, we used 5 (five) MDTs data: Light Detection And Ranging-LIDAR; Aerial Photography; Topodata; ASTER Global Digital Elevation Model-Aster GDEM; Shuttle Radar Topography Mission-SRTM, with different spatial resolutions and methods of acquisition. These data were applied a technique of hydrological correction and subsequently were extracted attributes from all surfaces. This information was used in the construction of the time of concentration and consequently the design hydrographs, which in turn were used to extract the maximum flow of project to return periods of 5, 10, 15, 20, 25, 50 and 100 years, in a range of the curve number (CN) varying between 40 and 99. It was built using a programming language of 60 dimension array rows by 7 columns, where each line represents the maximum values of each design hydrograph flow generated from each value of CN. In the end, it was obtained a set of 24 arrays containing the values of the maximum flows of project for each CN value, and attributes extracted of the MDTs and of digital models of terrain Hidrologicamente Consistent (MDEHCs). In possession of this information, a statistical test was applied in order to assess the influence that the hydrological consistency method and the dimensions of the cells of the MDTs/MDEHCs had about the project flows. Was observed in one of the sub-basins analysed that the difference between the maximum design flow is directly proportional to the increase in CN and payback period. It was noted a difference of up to 173.7 m3/s to a CN of 99 and return period of 100 years. The hypothesis H0 of the proposed test was accepted in all return periods both in relation to hydrological consistency method applied as compared to cell dimension of MDTs. This means that it is possible to affirm with an error probability of "P-value" for return period, which the flows generated from the parameters of the MDTs differ from flows generated from the parameters of MDEHCs as well as between the MDTs surveyed at a significance level of 5%. From the results, it might be concluded that the interpolation method for hydrological consistency and size of the cell of the MDTs has influence on the generation of the maximum flow of project. / No meio digital o relevo é melhor representado pelo modelo digital de terreno (MDT) e, a extração automática de atributos topográficos a partir deste tipo de dado, configura-se numa alternativa viável em relação ao processo manual realizado sobre mapas topográficos. No entanto, os dados disponíveis podem conter falhas ou apresentar informações de altitude que não sejam propriamente do terreno. Neste sentido é importante considerar essas questões na aplicação do MDT. Na hidrologia, por exemplo, é preciso realizar etapas de pré-processamento para eliminar incoerências que venham impedir a reprodução natural do fluxo da água em direção aos leitos dos rios. O objetivo desta pesquisa é verificar os limites de aplicabilidade dos MDTs em análises hidrológicas. Para isto, foram utilizados 5 (cinco) dados MDTs: Light Detection And Ranging - LIDAR; Aerofotogrametria; Topodata; ASTER Global Digital Elevation Model - Aster GDEM; Shuttle Radar Topography Mission – SRTM, com diferentes resoluções espaciais e métodos de aquisição. A esses dados foi aplicada uma técnica de correção hidrológica e posteriormente foram extraídos atributos de todas as superfícies. Estas informações foram utilizadas na construção do tempo de concentração e consequentemente dos hidrogramas de projeto, que por sua vez, foram utilizados para extrair a vazão máxima de projeto para os períodos de retorno de 5, 10, 15, 20, 25, 50 e 100 anos, em uma faixa de número da curva (CN) variando entre 40 e 99. Foi construída por meio de linguagem de programação uma matriz de dimensão 60 linhas por 7 colunas, onde cada linha representa os valores máximos de vazão de cada hidrograma de projeto gerado a partir de cada valor de CN. No final obteve-se um conjunto de 24 matrizes contendo os valores de vazões máximas de projeto para cada valor de CN, além de atributos extraídos dos MDTs e dos Modelos Digitais de Terreno Hidrologicamente Consistentes (MDEHCs). De posse dessas informações foi aplicado um teste estatístico, com o intuito de avaliar a influência que o método de consistência hidrológica e as dimensões das células dos MDTs/MDEHCs tiveram sobre as vazões de projeto. Foi observado em uma das sub-bacias analisadas que a diferença entre as vazões máximas de projeto é diretamente proporcional ao aumento do CN e período de retorno. Notou-se uma diferença de até 173,7 m3/s para um CN de 99 e período de retorno de 100 anos. A hipótese H0 do teste proposto foi aceita em todos os períodos de retorno tanto em relação ao método de consistência hidrológica aplicado quanto em relação ao tamanho da célula dos MDTs. Isto significa que é possível afirmar com uma probabilidade de erro de “P-Valor” por período de retorno, que as vazões geradas a partir dos atributos dos MDTs diferem das vazões geradas a partir dos atributos dos MDEHCs, assim como, entre os MDTs pesquisados a um nível de significância de 5%. A partir dos resultados pôde-se concluir que o método de interpolação para consistência hidrológica e tamanho da célula dos MDTs tem influência sobre a geração da vazão máxima de projeto.

L’homéostasie de la taille des cellules implique l’existence de mécanismes capables de coordonner la croissance (l’augmentation du volume) avec la prolifération (l’augmentation du nombre de cellules). Il est clairement établi que la taille des cellules est affectée par la disponibilité en nutriment du milieu de culture et par la ploïdie, mais les mécanismes sous-jacents demeurent inconnus. Une étude à l’échelle du génome réalisée chez la levure par l’équipe de M. Tyers a révélée que l’inactivation d’environ 400 gènes conduisait à un volume cellulaire moyen significativement différent de celui de la souche sauvage isogénique. Le contrôle de la taille des cellules est ainsi une situation intéressante dans laquelle de nombreux loci contribuent à un caractère quantitatif complexe. La plupart de ces loci demeurant orphelin de voie de signalisation distincte, leur influence respective reste à élucider. Nous avons commencé cette étude en partant de l’observation qu’un mutant sir2 présentait un volume cellulaire augmenté. De manière cohérente, un traitement au nicotinamide (Nam), un inhibiteur de Sir2, reproduit le défaut de taille de sir2 par un mécanisme dépendant de Sir2p. Nous avons alors pu, par une approche d’épistasie chimique, identifier 22 mutants non affectés par le traitement de la Nam, parmi ~200 mutants de petite taille. De manière surprenante, 16 de ces 22 mutants de taille insensibles à la NAM, sont affectés dans la biogenèse de la grande sous unité du ribosome (60S). Une drogue capable de bloquer spécifiquement la biogenèse tardive de la 60S, la diazaborine, mime le phénotype de taille des mutants de la 60S, produisant des cellules sauvages plus petites. Un ensemble de ~200 mutants de grande taille a été traité à la diazaborine et leur volume mesuré. Cette approche chimiogénétique nous a permis d’identifier 31 mutants insensibles à la diazaborine, incluant swi4 et swi6, deux régulateurs majeurs du cycle cellulaire, critiques pour le contrôle de la taille des cellules. Ces résultats furent confirmés par la construction de double mutants. Ce travail montre qu’il est possible d’organiser des mutants de taille au sein de voies spécifiques et de définir des relations d’épistasie claires entre eux. Nos données indiquent que le contrôle de la taille par cette voie “Sir2-60S” est indépendant des effets de la ploïdie et du contrôle nutritionnel sur la taille des cellules. / Cell size homeostasis implies that specific mechanisms are devoted to coordinating growth and proliferation. It is well established that cell size is affected by nutrient availability and ploidy but the underlying mechanisms are not elucidated. A genome wide search for yeast mutants affected for cell volume homeostasis, conducted in the Tyers’lab, revealed that the inactivation of about 400 genes leads to a median cell volume diverging from the isogenic wild-type. The cell size control process is thus a very interesting situation where multiple loci contributing to a complex quantitative trait have been identified but their organisation into distinct pathways and their respective influence remain largely to be elucidated. To address this issue, we started from the observation that a sir2 mutant shows an increased cell size. Consistently, nicotinamide (NAM), a Sir2 inhibitor, mimics the sir2 size defect in a Sir2p-dependent manner. This allowed us to identify among ~200 small size mutants, 22 mutants that were clearly not affected by NAM treatment. Strikingly, 16 out of the 22 NAM unresponsive mutants affected biogenesis of the large ribosomal subunit (named 60S below). Consistently, diazaborine, a drug that blocks the large ribosomal subunit assembly and therefore mimics 60S mutants, rendered wild-type yeast cells smaller. A set of ~200 large mutants were treated with diazaborine and their cell volume was measured. This chemogenetics approach allowed us to identify 31 diazaborine-unresponsive mutants, including swi4 and swi6, two major cell cycle regulators that are critical for cell size control. These results were confirmed by constructing double mutants. This work shows that it is possible to organize cell size mutants in specific pathways and to define clear epistasis relationships between them. Our data indicate that the control of cell size by the “Sir2-60S” pathway is independent of both the ploidy and the nutritional control of cell size.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24455号 / 理博第4954号 / 新制||理||1707(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 中野 伸一, 教授 木庭 啓介, 教授 中務 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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<p dir="ltr">In this dissertation, I use methods of theoretical physics to study principles governing the stochastic dynamics of living timekeepers in a few different contexts. First, focusing on the phenomenon of stochastic growth and division processes in the simplest living organism (the bacterial cell), I present a procedure for analyzing high-throughput, high-precision dynamic datasets to identify emergent simplicities, in particular scaling laws, that provide new insights into a long-standing problem (that of cell size homeostasis). Recasting the question from a stochastic, intergenerational viewpoint (i.e., one that considers the entire life histories of individual cells without recourse to a priori mechanistic assumptions), and taking advantage of identified emergent simplicities to achieve dimensional reduction of the problem, permits a reformulation that captures the inherent stochasticity of individual cells. Identification of discrete modes by which homeostasis is maintained---in particular, via reflexive (elastic) adaptation of cell size and reflective (plastic) adaptation of growth rate---provides important insights into key system constraints that govern living bacterial cells, with additional implications for the design of functional adaptive synthetic homeostats. The observation of non-Markovian dynamics in single-cell growth rates implies the existence of intergenerational memory and plastic adaptation in these simple organisms. I also present my work on the process of early endosomal maturation in human cell lines, multi- fork DNA replication in Escherichia coli cells, and a physics principle and theory predictions for emergent periodicity in a decentralized follow-the-leader dynamic in a collective of randomly signaling agents. This body of work provides mechanistic insights into how temporal organization in outcomes emerges despite the inherently stochastic nature of the constituent dynamics, with each system adopting its own mechanism to achieve this universal goal.</p>

O presente trabalho teve como objetivo: 1. Determinar o efeito de diferentes tamanhos de células de cria de operárias (favos novos construídos naturalmente por abelhas Africanizadas e européias e favos velhos) sobre o peso e variabilidade morfológica das abelhas operárias emergentes em colônias de abelhas (Apis mellifera); 2. Examinar a influência das células de operárias de menor tamanho do favo velho em relação às células novas construídas por abelhas Africanizadas e às células de operárias construídas por abelhas européias (italianas e cárnicas) sobre a infestação e reprodução do ácaro Varroa jacobsoni. O trabalho foi todo realizado no Departamento de Genética da FMRP-USP em Ribeirão Preto. Foram utilizadas colônias de abelhas africanizadas do próprio apiário experimental (N=8). Foram usados neste experimento quatro tipos de favos: favo africanizado novo (FAFn), favo italiano novo (FITn), favo cárnico novo (FCAn) e favo velho africanizado (FVE) com as paredes das células engrossadas por efeito de muitas gerações de abelhas emergidas. Um total de três medidas foram feitas nas células de operárias de cada favo: diâmetro da célula (DC), profundidade da célula (PC) e peso da abelha emergente (PA). O volume da célula (VC) foi calculado a partir do DC e da PC. As abelhas, uma vez pesadas, foram posteriormente preservadas em solução de álcool a 70%. As seguintes medidas morfométricas foram tomadas sobre cada abelha individual e sobre a asa anterior direita: Comprimento e Largura total da asa anterior direita. Investigamos os índices de infestação e as taxas de reprodução do ácaro nos quatro tipos de favos com diferentes células de crias de operárias, para verificar possíveis variações na infestação entre os favos estudados. Para as dimensões das células (DC, PC e VC), entre o favo FVE e os novos (FAFn, FITn e FCAn), observou-se de maneira geral que o DC e VC foram as medidas que apresentaram diferenças notáveis entre os diferentes favos. Comparando-se os diâmetros das células de cria entre os favos estudados, percebe-se uma média menor para as células do FVE (4.56 mm) e médias maiores para as células dos favos FITn (5.13 mm) e FCAn (5.27 mm); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Em relação à PC a situação foi inversa, percebe-se que a PC construída pelas operárias a partir da cera alveolada (FITn) foi de 11.62 mm e a PC em favos construídos por operárias cárnicas (FCAn) foi de 11.64 mm, sendo inferiores às do FVE (12.22 mm). As médias dos volumes dos diferentes tipos de alvéolos estudados mostram uma média menor para as células do FVE (220.12 mm3) e médias maiores para os FITn (264.82 mm3) e FCAn (279.59 mm3); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Os resultados indicaram que as abelhas compensaram a menor ou maior largura da célula ao produzir células com maior ou menor profundidade respectivamente. Das asas analisadas, as operárias do FVE apresentaram menor comprimento (9.10 mm), enquanto que esses comprimentos foram bem maiores nas operárias do favo FAFn, FITn e FCAn sendo 9.26 mm, 9.32 mm e 9.32 mm respectivamente. Em relação à largura da asa, encontramos também que as operárias do FVE apresentaram menor largura (3.31 mm), sendo essas medidas maiores nas operárias dos favos novos FAFn, FITn e FCAn (3.43 mm, 3.49 mm e 3.46 mm respectivamente). O comprimento e largura da asa anterior direita das abelhas emergentes diferiram estatisticamente entre os quatro tipos de favos estudados (p= 0.014 e p= 0.003 respectivamente, One-Way ANOVA). Comparando-se o peso médio das operárias ao nascer, entre os diferentes tipos de células de crias do FVE (88.12 mg), FAFn (92.67 mg), FITn (95.82 mg) e FCAn (96.89 mg) percebe-se que ocorre um acréscimo no peso à medida que o tamanho da célula é aumentado. A comparação do peso das operárias mostrou que ocorrem diferenças altamente significantes em nível de 5% de probabilidade entre os diferentes favos de cria (p<0.001, One-way ANOVA). Comparando-se o peso médio das abelhas operárias emergentes infestadas e não infestadas pela varroa, percebe-se que ocorre um forte decréscimo no peso da abelha infestada em 14.9% para o FVE e FAFn. Os índices de infestação da varroa verificados nos diferentes tamanhos de células de operárias diferiram estatisticamente entre os quatro tipos de favos (x2 = 41.122, p< 0.001). A infestação média do ácaro foi maior em células de cria do FVE que em células do favo FAFn que apresentou menor índice de infestação (20.6 ± 6.4% vs 10.4 ± 4.2% respectivamente). Esses índices médios diferiram estatisticamente (p< 0.001). Houve maior número de fêmeas adultas do ácaro em células do FVE, que apresentou menor diâmetro e menor volume da célula, comparado com as células dos favos novos de maiores tamanhos (FAFn, FITn e FCAn). Obtiveram-se taxas de reprodução total de 1.28, 0.98, 1.19 e 1.58 para os favos FVE, FAFn, FITn e FCAn respectivamente, quando computadas todas as varroas adultas originais. Essas taxas de reprodução total do ácaro não apresentaram diferenças significativas entre si (p= 0.074, One-Way ANOVA). As células do FVE atraíram mais varroa em relação às células dos favos novos, apesar de que as células do FVE tiveram um diâmetro menor. Embora o tamanho da célula seja importante, característica inerente à larva, ao favo ou ao alimento nas células de crias do FVE poderiam ter uma importante influência de atração ao ácaro varroa. / The purposes of the present work were: 1. To determine the effect of different sizes of worker brood cells in new and old combs built naturally by Africanized and European bees on the weight and morphology of emerging worker honey bees in africanized honey bee colonies (Apis mellifera). 2. To examine the influence of the smaller worker cells of the old comb in relation to new cells built by Africanized bees and larger new cells built by European races on the infestation and reproduction rates of the mite Varroa jacobsoni. We used eight Africanized honey bee colonies. Four types (sizes) of brood combs were placed in each colony: new Africanized comb (NAC), new Italian comb (NIC), new Carniolan comb (NCC) and old Africanized brood comb (OC), that had thickened brood cell walls and relatively small comb cells. Three measurements were made for 80-100 worker brood cells in each comb: Cell width (CW), cell depth (CD), and emerging bee weight (BW). Cell volume (CV) was calculated from CW and CD. The bees were weighed and then preserved in a 70% ethanol. The length and width of the right fore wing were measured for each individual bee. We studied the infestation and the reproduction rates of the mite in four types of combs with different kinds of worker brood cells, to verify possible variations in the infestation by varroa. The comb cell measurements CW and CV differed significantly among the various types of combs. We found that the OC cells (4.56 mm) had a significantly (p <0.001, One-Way ANOVA) smaller diameter than the NIC cells (5.13 mm) and NCC cells (5.27 mm). An opposite trend was found for cell depth, which was significantly smaller in NIC (11.62 mm) and NCC (11.64 mm) than OC (12.22 mm). For the different types of brood combs, the cell depth increased as the cell diameter decreased, in other words, the bees compensated the reduced cell width by producing deeper cells to accommodate the developing bee. The OC cells had a significantly smaller volume (220.12 mm3) than the NIC cells (264.82 mm3) and NCC cells (279.59 mm3) (p< 0.001, One-Way ANOVA). The worker bees reared in OC had a significantly shorter fore wing (9.10 mm) than in the new worker combs NAC (9.26 mm), NIC (9.32 mm) and NCC (9.32 mm). Fore wing width, was also significantly smaller for workers from OC combs (3.31 mm), than from NAC, NIC and NCC combs (3.43 mm, 3.49 mm and 3.46 mm, respectively). The right fore wing length and width of the emerging workers bees differed significantly among the four types of combs (p = 0.014 and p = 0.003 respectively, One-Way ANOVA). In summary, the wing size of the emerging worker bees increased with increasing volume and diameter of the comb cell. The bees from the OC comb had significantly smaller fore wings (both length and width) than those from NAC comb (p< 0.05, Tukey Test). The same was true for workers from NIC and NCC combs. The mean weights of the worker bees among the different types of brood combs were: 88.12 mg, 92.67 mg, 95.82 mg and 96.89 mg for OC, NAC, NIC and NCC respectively. There was an increment in bee weight as the diameter of the cell increased. Bee weights from the different types of combs were significantly different (p< 0.001, One-way ANOVA). Bees infested during the brood phase with the mite Varroa jacobsoni weighed on average 14.9% less than uninfested bees. The varroa infestation rates differed significantly among the four types of combs (x2= 41.122, p< 0.001). The varroa infestation was significantly (p< 0.001) higher in OC cells (20.6±6.4%) than in NAC cells (10.4±4.2%) and NIC cells (14.7%, p= 0.003). The mean infestation rate in NIC cells did not differ significantly (p= 0.094) from the infestation rate in NCC cells (19.2%). The infestation rate in OC cells was not significantly different from that of NCC cells (p= 0.347). Within each colony the OC comb was generally twice as infested with varroa as NAC. The total varroa reproduction rate (TRR) was 1.28, 0.98, 1.19 and 1.58 for the OC, NAC, NIC and NCC combs respectively, when we included all the original adult females (p= 0.074, One-way ANOVA). The OC cells attracted more varroa than new comb cells, even though the OC cells had a smaller diameter. Though cell size is important, characteristics inherent to the larvae, to the comb or the food in the OC worker cells apparently have an overriding influence on attractiveness to the varroa mite.