In the face of ever increasing atmospheric CO₂ a better understanding of soil properties and processes and the effect of management practices, such as the application of nitrogen fertilizer is of importance and could potentially improve our ability to sustainably manage forestry systems. With that in mind this study was conducted in order to investigate the effects of tree species and fertilization on soil carbon and the soil microbial community. To this end, soil from fertilized and unfertilized plots at Berwick forest, under stands of Pinus radiata and Sequoia sempervirens at Hanmer and under six different tree species at Holt forest was sampled. Two glasshouse pot trials were established using soil collected from the Hanmer and Berwick forest sites and seedlings of Pinus radiata, Sequoia sempervirens, and Eucalyptus nitens were grown. Soil properties were determined from both the field sites and pot trials including soil organic matter, carbon, nitrogen, and microbial biomass by chloroform fumigation extraction. Biolog ecoplates were used to determine the relative differences in diversity based on substrate utilization patterns of the soil microbial communities in soil sampled from the glasshouse pot trials. Soil microbial biomass carbon, nitrogen and the ratio of microbial biomass carbon:nitrogen differed significantly between Pinus radiata and the other tree species sampled at Holt forest. Significant effects of fertilization and tree species on soil carbon and microbial biomass were observed in both pot trials. Soil carbon differed significantly between Eucalyptus nitens and both Pinus radiata and Sequoia sempervirens in the first pot trial and relative to both, E. nitens contributed significantly more carbon. No significant effect of either fertilization or tree species on the catabolic diversity of the soil microbial community in both glasshouse pot trials was observed. The results demonstrated the effects that fertilization and tree species can have. Particularly notable was the short-time period in which tree species effects became apparent coupled with the absence of any aboveground inputs to the soil.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2008.

BACKGROUND: Diaclyglycerol (DAG) oil has the potential as an effective weight control agent as well as an agent to modify overweight related complications. OBJECTIVE: We aim to examine the efficacy of DAG oil (Enova oilTM) on regulating energy expenditure (EE), fat oxidation, body composition, lipid profiles and hepatic lipogenesis in comparison with conventional oils. DESIGN: Twenty-six overweight hypertriglyceridemic women consumed DAG or control oil for 28 days separated by a 4-week washout period using a randomized crossover design. Forty grams of either DAG or control oil were consumed daily by each study subject. RESULTS: DAG oil consumption for a period of 4-week does not alter total EE, fat oxidation, lean mass, fasting lipid profile or fatty acids synthesis rate, but effectively reduces (p<0.05) body weight and adiposity. CONCLUSION: DAG oil maybe an useful agent in the battle against obesity. However, its body weight/composition control effects are not from increasing of lean mass, or postprandial EE and fat oxidation. The consumption of DAG oil for a period of 4-week does not necessarily modify fasting lipid profiles or hepatic lipogenesis to reduce risk of coronary heart diseases in overweight hypertriglyceridemic subjects.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2008.

This study compares the role of cognitive processes in children diagnosed with learning disabilities (LD) through the traditional aptitude-achievement discrepancy model with students diagnosed on the basis of their low achievement alone. Historically, in North American settings, LD has been diagnosed when an individual’s achievement on standardized tests in reading, mathematics, or written expression is substantially lower than the expected level for age, schooling, and level of intelligence (American Psychiatric Association, 2000). As this conceptualization has come under increasing scrutiny, alternate identification methods such as the low achievement/non-discrepant method have been gaining support in the literature (e.g. Siegel, 1999; Stanovich, 2005). A secondary objective of this study is to determine whether identifiable differences exist between the cognitive profiles (WISC-IV) of students diagnosed with reading disability (RD) and mathematics disability (MD). This study also addresses whether the WISC-IV Working Memory Index can be used to differentiate between various categories of students with LD. The findings of this study indicate that the discrepant (DLD) and non-discrepant (NDLD) learning disability (LD) groups could not be distinguished by the WISC-IV Working Memory Index (WMI). Amongst the overall sample of students with LD, those with average or above working memory scores (high) could be differentiated from those with below average working memory scores (low) on the WISC-IV Perceptual Reasoning Index (PRI). Students with LD who had low WMI scores could also be differentiated from those with high WMI scores on four WIAT-II subtests. WMI scores could not be used to differentiate students with Reading Disability (RD), Mathematics Disability (MD) or Generalized Learning Disability (GLD). However, differences between these three LD groups were found on the WISC-IV Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), and marginally on the Processing Speed Index (PSI). Finally, the four WISC-IV Index scores were able to correctly predict group membership in the RD, MD, and GLD groups approximately 70% of the time. / Psychological Studies in Education

Communication is one team process factor that has received considerable research attention in the team literature. This literature provides equivocal evidence regarding the role of communication in team performance and yet, does not provide any evidence for when communication becomes important for team performance. This research program sought to address this evidence gap by a) testing task complexity and team member diversity (race diversity, gender diversity and work value diversity) as moderators of the team communication — performance relationship; and b) testing a team communication — performance model using established teams across two different task types. The functional perspective was used as the theoretical framework for operationalizing team communication activity. The research program utilised a quasi-experimental research design with participants from a large multi-national information technology company whose Head Office was based in Sydney, Australia. Participants voluntarily completed two team building exercises (a decision making and production task), and completed two online questionnaires. In total, data were collected from 1039 individuals who constituted 203 work teams. Analysis of the data revealed a small number of significant moderation effects, not all in the expected direction. However, an interesting and unexpected finding also emerged from Study One. Large and significant correlations between communication activity ratings were found across tasks, but not within tasks. This finding suggested that teams were displaying very similar profiles of communication on each task, despite the tasks having different communication requirements. Given this finding, Study Two sought to a) determine the relative importance of task versus team effects in explaining variance in team communication measures for established teams; b) determine if established teams had reliable and discernable team communication profiles and if so, c) investigate whether team communication profiles related to task performance. Multi-level modeling and repeated measures analysis of variance (ANOVA) revealed that task type did not have an effect on team communication ratings. However, teams accounted for 24% of the total variance in communication measures. Through cluster analysis, five reliable and distinct team communication profiles were identified. Consistent with the findings of the multi-level analysis and repeated measures ANOVA, teams’ profiles were virtually identical across the decision making and production tasks. A relationship between communication profile and performance was identified for the production task, although not for the decision making task. This research responds to calls in the literature for a better understanding of when communication becomes important for team performance. The moderators tested in this research were not found to have a substantive or reliable effect on the relationship between communication and performance. However, the consistency in team communication activity suggests that established teams can be characterized by their communication profiles and further, that these communication profiles may have implications for team performance. The findings of this research provide theoretical support for the functional perspective in terms of the communication – performance relationship and further support the team development literature as an explanation for the stability in team communication profiles. This research can also assist organizations to better understand the specific types of communication activity and profiles of communication that could offer teams a performance advantage.

Made available in DSpace on 2014-06-11T19:32:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-14Bitstream added on 2014-06-13T20:04:32Z : No. of bitstreams: 1 matsumoto_mt_dr_arafcf.pdf: 7554122 bytes, checksum: 0910afc354605fb9e82889bf3660ea86 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Cryptococcus neoformans é patógeno importante, principalmente em pacientes imunocomprometidos. A principal porta de entrada deste patógeno é pela via respiratória, disseminando-se posteriormente e atingindo principalmente o sistema nervoso central, provocando a meningite criptocóccica. A primeira parte deste estudo teve como objetivos determinar, nos 106 isolados clínicos de C. neoformans obtidos de dois Estados (São Paulo e Rio de Janeiro), (1) as variedades e (2) os mating-types por PCR (Polymerase Chain Reaction), (3) analisar a diversidade genética por PCR-fingerprinting com a seqüência iniciadora específica para regiões microssatélite (GACA)4, (4) por RAPD (Random Amplification of Polymorphic DNA) com o iniciador 6 e (5) por PCR-RFLP (Restriction Fragment Length Polymorphism) do gene da fosfolipase B (PLB1) digerido com a enzima de restrição AvaI e (6) determinar a sensibilidade a quatro antifúngicos (fluconazol, itraconazol, 5-fluorocitosina e anfotericina B) seguindo o método de referência (documento M27-A2) do CLSI (Clinical and Laboratory Standards Institute). A segunda parte teve como objetivo, analisar transcritos diferencialmente expressos durante a infecção pulmonar de C. neoformans, pela técnica de RDA (Representational Difference Analysis). Entre os 106 isolados, 104 foram identificados como C. neoformans e apenas dois foram C. gattii (=C. neoformans var. gattii), todos MATa. O tipo molecular VNI (C. neoformans var. grubii, sorotipo A) foi o mais prevalente entre os isolados (97/106), seguido do tipo VNII (C. neoformans var. grubii, sorotipo A) (7/106) e VGII (C. gattii, sorotipos B ou C) (2/106) quando analisados por PCR-fingerprinting e PCR-RFLP. Homogeneidade alta foi obtida com o iniciador (GACA)4, com a maioria dos isolados apresentando correlação em torno de 0,9. Os resultados do RAPD, por sua vez, revelaram maior heterogeneidade com número maior de perfis moleculares. / Cryptococcus neoformans is an important pathogen, mainly in immunocompromised patients. The pathogen penetrates mainly by respiratory way, disseminate afterward and reach specially the central nervous system causing the cryptococcal meningitis. The first part of this study had the objective to determine, in the 106 clinical isolates of C. neoformans obtained from São Paulo and Rio de Janeiro State, (1) the varieties and (2) mating-types by PCR (Polymerase Chain Reaction), (3) analyze the genetic diversity by PCR-fingerprinting with specific primer to microsatellite regions (GACA)4, (4) by RAPD (Random Amplification of Polymorphic DNA) with primer 6 and (5) by PCR-RFLP (Restriction Fragment Length Polymorphism) of the phospholipase B gene (PLB1) digested with restriction enzyme AvaI and (6) to determine the susceptibility to four antifungal (fluconazole, itraconazole, 5-flucytosine and amphotericin B) following the reference method (document M27-A2) from CLSI (Clinical and Laboratory Standard Institute). The second part had the goal to analyze differentially expressed transcription during pulmonary infection of C. neoformans, by RDA (Representational Difference Analysis) technique. Among 106 isolates, 104 were identified as C. neoformans and only two were C. gattii (=C. neoformans var. gattii), all MATa. The molecular type VNI (C. neoformans var. grubii, serotype A) was the most prevalent among the isolates (97/106), followed by VNII (C. neoformans var. grubii, serotype A) (7/106) and VGII (C. gattii, serotypes B ou C) (2/106) when analyzed by PCR-fingerprinting and PCR-RFLP. High homogeneity was obtained with the primer (GACA)4, with most of the isolates showing correlation around 0.9. By contrast, the RAPD analysis revealed more heterogeneous with more numbers of molecular profiles.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically significant viral diseases facing the global swine industry. Viraemia profiles of PRRS virus challenged pigs reflect the severity and progression of infection within the host and provide crucial information for subsequent control measures. In this thesis we analyse the largest longitudinal PRRS viraemia dataset from an in-vivo experiment, and corresponding immune measures in the form of cytokine data and neutralising antibodies. In the PRRS Host Genetic Consortium (PHGC) trials, pigs were challenged with one of two PRRSV isolates (NVSL and KS06, respectively). In Chapter 2 we derive a statistical description of the temporal changes in viraemia and determine the influence of diverse factors (e.g. PRRSV strain, pig genetic background, resistance genotype, etc.) on viraemia profiles. The well-established methodology of linear mixed modelling with a repeated measures model and fitting a linearized Wood’s function, a gamma-type function, is applied to the viraemia dataset. The virus isolate had a significant impact on the viraemia profiles which was captured by statistically significant differences in model parameters via both statistical methods. The more virulent NVSL isolate had higher early viraemia predictions and a faster rate of decline than KS06. In line with previous studies the WUR “resistance” genotype, associated with lower AUC viraemia found in previous studies, also resulted in lower viraemia predictions in the statistical models. The typical time trends of the viraemia profiles were a rise to a peak followed by a period of decline with dynamics and magnitude influenced by the virus isolate. Both uni and bimodal viraemia profiles were observed. The Wood’s model appeared a suitable candidate model for the data associated with uni-modal profiles and captured the time trends concisely in only three model parameters which also had a biological relevance. Overall the best fitting Wood’s model (y=atbe-ct) was when there was a random effect in Wood’s parameters b and c. Bimodal profiles significantly reduced the model fit, particularly in the later phase of infection resulting in large model residuals. However bimodal profiles did not impact upon the significance of the differences between the LSM repeated measures estimates nor the LSM linearized Wood’s model parameter estimates. The longitudinal viraemia measures from the PRRSV challenge experiment revealed substantial differences in the viraemia profiles between hosts infected with the same PRRSV challenge dose, pointing to considerable variation in the host response to PRRSV infections. In Chapter 3 we provide a suitable mathematical description of all viraemia profiles with biologically meaningful parameters for quantitative analysis of profile characteristics. The Wood’s function and a biphasic extended Wood’s function were fit to the individual profiles using Bayesian inference with a likelihood framework in Chapter 3. Using maximum likelihood inference and numerous fit criteria, we established that the broad spectrum of viraemia trends could be adequately represented by either uni-or biphasic Wood’s functions. Three viraemic categories emerged: cleared (uni-modal and below detection within 42 days post infection(dpi)), persistent (transient experimental persistence over 42 dpi) and rebound (biphasic within 42 dpi). The convenient biological interpretation of the model parameters estimates, allowed us not only to quantify inter-host variation, but also to establish common viraemia curve characteristics and their predictability. The convenient biological interpretation of the model parameters estimates, allowed us not only to quantify inter-host variation, but also to establish common viraemia curve characteristics and their predictability, which were utilized in subsequent quantitative genetic analyses to identify genomic regions associated with these new resistance traits. The Bayesian approach for curve fitting in Chapter 3 led to better model fits than the classical linear mixed models approach of Chapter 2. Furthermore in Chapter 4 we explored the association between the observed PRRS viraemia profile characteristics and the corresponding measures of the immune response in the form of: neutralising antibody (nAb) cross protection data and longitudinal cytokine profiles. Statistical analysis of the profile characteristics revealed that persistent profiles were distinguishable already within the first 21 dpi, whereas it is not possible to predict the onset of viraemia rebound. Analysis of the neutralizing antibody (nAb) data indicated that there was a ubiquitous strong response to the homologous PRRSV challenge, but high variability in the range of cross-protection of the nAbs. Persistent pigs were found to have a significantly higher nAb cross-protectivity than pigs that either cleared viraemia or experienced rebound within 42 dpi. We determined the typical features and time trends of each cytokine profile, examined the associations between cytokines, and characterised the cytokine response. A stronger association was found in the direction of cytokines driving the ensuing viraemia characteristics as opposed to vice versa. It was found that viraemia class differences were best captured in the anti-viral cytokine IFNA and also the chemokine CCL2, furthermore these key cytokines were the most strongly associated with viraemia measures. The breadth of the cytokine responsiveness was associated with viral profile class and genetic background but not the WUR genotype. The statistical categorization of pigs from each PHGC trial through model fitting provides a critical basis for the generation of new desirable host phenotypes, and of potential use in the genetic selection of pigs with favourable infection traits. Our study provides novel insights into the nature and degree of variation of hosts’ responses to infection as well as new informative traits for subsequent genetic and modelling studies.

Orientador: Marco Antonio Alvarenga / Resumo: Respostas superovulatórias satisfatórias têm sido reportadas em éguas com o uso do Extrato de Pituitária Eqüina (EPE) e FSH purificado eqüino (eFSH), contudo as taxas de recuperação embrionária permanecem inconsistentes. O objetivo deste estudo foi avaliar as concentrações plasmáticas de estradiol, inibina, FSH e LH em éguas superovuladas com eFSH e EPE (em doses constantes ou decrescentes): antes, durante e imediatamente após o término da administração hormonal. Foram utilizadas seis éguas as quais foram submetidas aos seguintes tratamentos: Grupo I (GI) recebeu 25mg de EPE intramuscular (I.M.), Grupo II (GII) foram tratadas com EPE (I.M.) em doses decrescentes. No Grupo IIl (GIII), o EPE foi substituído por 12,5mg de eFSH (I.M.). O Grupo IV (GIV) foi utilizado como controle. Sangue foi coletado diariamente para avaliar as concentrações hormonais por radioimunoensaio. As coletas foram iniciadas dois dias antes da primeira aplicação medicamentosa, encerrando 48horas após a última ovulação do estro. As diferenças nos níveis plasmáticos hormonais foram comparadas utilizando-se o ANOVA, sendo considerada diferença estatística quando P0,05. O número médio de ovulações foi de 3,3; 4,8; 5,0 e 1,0 nos grupos 1 a 4, respectivamente, tendo sido maior (P<0,05) em todos os grupos superovulados em relação ao controle. As concentrações de estrógeno, inibina, FSH e LH não diferiram entre os grupos durante o período 1. No período 2, os valores de estradiol foram maiores (P<0,05) em éguas sob tratamento superovulatório com eFSH (GIII) 29,52pg/ml, os grupos I e II, apresentaram valores intermediários (GI: 16,75pg/ml, GII: 16,26pg/ml) e o GIV (7,78pg/ml) menor estatisticamente aos demais. Foi verificada uma correlação altamente positiva (R=0,615; P=0,01) entre os valores de estradiol e inibina, os quais, durante os tratamentos, foram maiores (P<0,05)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Satisfactory superovulatory responses have been reported in mares with the use of equine pituitary extract (EPE) and purified equine FSH (eFSH), however embryo recovery rates are still inconsistent. Recent studies demonstrated that the superovulatory treatment disturbs oocyte maturation and transport. The main objective of the present study was to evaluate the plasmatic concentrations of estradiol, inhibin, FSH and LH in super ovulated mares treated with eFSH and EPE (with constant or decreasing doses): Six mares were used in a crossover experiment in four different groups: Group I mares received 25mg of EPE every twelve hours, Group II received EPE in decreasing doses and Group IlI mares received 12.5mg of eFSH (IM). Group IV served as control. Embryo flushes were performed 8 days pos ovulation. Blood was collected daily to evaluate hormonal concentrations through radioimuneassay, starting two days before the first administration, until 48 hours post-ovulation. Mean and daily hormonal concentrations of estradiol, inhibin, FSH and LH were evaluated. Hormonal concentrations were submitted to statistical analysis using ANOVA. Significance levels were set as P<0.05. Mean number of ovulations was 3.3; 4.8; 5.0 and 1.0 in groups 1 to 4, respectively, being higher (P<0.05) in all super ovulated groups, when compared to control. Concentrations of estrogen, inhibin, FSH and LH did not differ between groups during the first period. In period 2, estradiol levels were higher (P<0.05) in mares with superovulatory treatment eFSH (GIII) 29.52pg/ml, the groups GI and GII (GI: 16.75pg/ml, GII: 16.26pg/ml) values intermediary, and GIV (7.78pg/ml) levels lower. A positive correlation between estradiol levels and number of follicles ≥30mm (R=0.917; P<0.05), recovered embryos (R=0.945; P<0.05) and ovulations (R=0.75; P<0.05) was identified in super ovulated mares. A positive correlation (R=0.615; P=0.01) between estradiol and inhibin concentrations. / Mestre

Orientador: Maria José Soares Mendes Giannini / Banca: Benedito Barraviera / Banca: Paulo Inácio da Costa / Banca: Célia Maria de Almeida Soares / Banca: Clarice Queico Fujimura Leite / Resumo: Cryptococcus neoformans é patógeno importante, principalmente em pacientes imunocomprometidos. A principal porta de entrada deste patógeno é pela via respiratória, disseminando-se posteriormente e atingindo principalmente o sistema nervoso central, provocando a meningite criptocóccica. A primeira parte deste estudo teve como objetivos determinar, nos 106 isolados clínicos de C. neoformans obtidos de dois Estados (São Paulo e Rio de Janeiro), (1) as variedades e (2) os mating-types por PCR (Polymerase Chain Reaction), (3) analisar a diversidade genética por PCR-fingerprinting com a seqüência iniciadora específica para regiões microssatélite (GACA)4, (4) por RAPD (Random Amplification of Polymorphic DNA) com o iniciador 6 e (5) por PCR-RFLP (Restriction Fragment Length Polymorphism) do gene da fosfolipase B (PLB1) digerido com a enzima de restrição AvaI e (6) determinar a sensibilidade a quatro antifúngicos (fluconazol, itraconazol, 5-fluorocitosina e anfotericina B) seguindo o método de referência (documento M27-A2) do CLSI (Clinical and Laboratory Standards Institute). A segunda parte teve como objetivo, analisar transcritos diferencialmente expressos durante a infecção pulmonar de C. neoformans, pela técnica de RDA (Representational Difference Analysis). Entre os 106 isolados, 104 foram identificados como C. neoformans e apenas dois foram C. gattii (=C. neoformans var. gattii), todos MATa. O tipo molecular VNI (C. neoformans var. grubii, sorotipo A) foi o mais prevalente entre os isolados (97/106), seguido do tipo VNII (C. neoformans var. grubii, sorotipo A) (7/106) e VGII (C. gattii, sorotipos B ou C) (2/106) quando analisados por PCR-fingerprinting e PCR-RFLP. Homogeneidade alta foi obtida com o iniciador (GACA)4, com a maioria dos isolados apresentando correlação em torno de 0,9. Os resultados do RAPD, por sua vez, revelaram maior heterogeneidade com número maior de perfis moleculares. / Abstract: Cryptococcus neoformans is an important pathogen, mainly in immunocompromised patients. The pathogen penetrates mainly by respiratory way, disseminate afterward and reach specially the central nervous system causing the cryptococcal meningitis. The first part of this study had the objective to determine, in the 106 clinical isolates of C. neoformans obtained from São Paulo and Rio de Janeiro State, (1) the varieties and (2) mating-types by PCR (Polymerase Chain Reaction), (3) analyze the genetic diversity by PCR-fingerprinting with specific primer to microsatellite regions (GACA)4, (4) by RAPD (Random Amplification of Polymorphic DNA) with primer 6 and (5) by PCR-RFLP (Restriction Fragment Length Polymorphism) of the phospholipase B gene (PLB1) digested with restriction enzyme AvaI and (6) to determine the susceptibility to four antifungal (fluconazole, itraconazole, 5-flucytosine and amphotericin B) following the reference method (document M27-A2) from CLSI (Clinical and Laboratory Standard Institute). The second part had the goal to analyze differentially expressed transcription during pulmonary infection of C. neoformans, by RDA (Representational Difference Analysis) technique. Among 106 isolates, 104 were identified as C. neoformans and only two were C. gattii (=C. neoformans var. gattii), all MATa. The molecular type VNI (C. neoformans var. grubii, serotype A) was the most prevalent among the isolates (97/106), followed by VNII (C. neoformans var. grubii, serotype A) (7/106) and VGII (C. gattii, serotypes B ou C) (2/106) when analyzed by PCR-fingerprinting and PCR-RFLP. High homogeneity was obtained with the primer (GACA)4, with most of the isolates showing correlation around 0.9. By contrast, the RAPD analysis revealed more heterogeneous with more numbers of molecular profiles. / Doutor