Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 5 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

>Magister Scientiae - MSc / Lab conducted proximate analysis of coal bearing rock units calculates the weight percentage of ash, moisture, fixed carbon and volatile matter through a series of combustion steps. The data obtained is quintessential in establishing the coal rank and in the case of coal bed methane the gas-in-place estimates. In this study 105 proximate analysis samples, from 7 drilled wells, are taken from the south-eastern Kalahari Basin in Botswana. The pseudo proximate analysis, the method proposed in this thesis, calculates the lab proximate analysis results using the neutron, density and gamma ray wireline logs. The uniqueness of the method lies in the fact that no cut off values are needed for the wireline logs, nor are the results of the lab proximate analysis required for calibration. An in depth study of the relationship between the wireline logs and proximate analysis is conducted using a principle component analysis and the results tested using a combination of statistical techniques to determine the significance of the relationship. It is shown that the density and neutron logs model the proportion of ash and volatile matter in the rock matrix, respectively, with a high degree of accuracy. The multiple regression analysis shows that percentages fixed carbon and moisture components of the rock matrix correlate poorly to the proposed well logs, thus most error lies in the determination of these two components. It is statistically proven that the pseudo proximate analysis results are significantly different to the lab measured proximate analysis. This implies that the proposed pseudo proximate analysis method is unable to accurately determine the components of a coal bearing rock matrix using the density, neutron and gamma ray wireline logs. The application of the proposed method is a model to identity the coal bearing rock matrix and provide a predictive estimation of the coal quality, a priori lab measured data.

Condition indices are widely used to generate biological insight. However, purported relationships to indices are imprecise or inconsistent in the wild. I investigated factors influencing relative weight (Wr), a condition index commonly applied to fish. I first examined the relationship of Wr to physiology in two bluegill Lepomis macrochirus populations over a year. I regressed tissue composition (percentages of lipid, protein and water) and organ indices (liver-, gonad-, and viscerosomatic indices) on Wr. The regression model had little explanatory power (adjusted R2 = 0.14). Lipid was most influential (partial R2 = 0.11), but correlation strength fluctuated by season and population. To test the generality of these results, I performed a similar regression on a bluegill population with higher average Wr. Again, variables were not well correlated to Wr (adjusted R2 = 0.13). Combining comparable data sets increased Wr range 64% but explanatory power was low (adjusted R2 = 0.41) Both studies showed that expected correlations of physiological variables to Wr can be confounded in natural environments. To examine differences between natural and laboratory environments, I manipulated initial Wr and ration of juvenile bluegills. Although organ indices and tissue composition of all groups changed in time ((Wilks' Δ > 0.387, P > 0.03), no temporal pattern matched to Wr. At termination, all variables showed high correlations to Wr (r2 > 0.64). Correlation strength increased with time in the laboratory. Both ration and environment influenced correlations. Lastly, I examined differences in interpretation of Wr for chain pickerels Esox niger, largemouth bass Micropterus salmoides, and black crappies Pomoxis nigromaculatus. Regression models were compared to concurrent bluegill models. Piscivore models fit well (adjusted R2 > 0.50), whereas bluegill models had the lowest explanatory power (adjusted R2 = 0.13 and 0.14). Ecological specialization affected correlations to Wr. Theoretically, condition index values are determined by resource acquisition versus expenditure. Exact physiological expression is determined by life history and performance. Condition indices are imprecise predictors but track net somatic investment with great generality. Ancillary data, such as growth or length-at-maturity, may clarify interpretation. Condition indices should be used as qualitative monitoring tools, not omnibus physiological predictors. / Ph. D.

Pacific bluefin tuna (PBT; Thunnus orientalis) has grown significantly in popularity in recent years due to the globalization of Japanese cuisine. PBT is highly sought after for sushi and sashimi products due to its great quality and taste. Wild populations of this species have been affected by their increasing popularity, pushing innovators in the food industry to create meat alternative versions of PBT. The muscle composition of PBT varies, leading to different types (cuts) of meat in a way that is analogous to various cuts of beef. This study evaluated the differentiation amongst the 6 distinct cuts, including otoro, ventral akami, dorsal akami, ventral chu-toro, dorsal chu-toro, and wakaremi conducting volatile analysis, proximate analysis, and fatty acid analysis. The results from these analyses can then be used as a base standard for companies seeking to create alternatives versions of PBT. Samples analyzed in this study were cultured PBT species that were caught as juveniles and raised in captivity on a PBT farm in Mexico. Volatile analysis was conducted using a SPME GC/MS method. Overall, 41 aroma compounds were identified in PBT that met the identification criteria, including 9 aldehydes, 7 alcohols, 14 alkanes, 2 ketones, 4 alkenes, 3 aromatic compounds, and 2 miscellaneous compounds. Proximate analyses were conducted using standard methods. Significant differences (p <0.05) were found between each cut for the proximate analysis. The fatty acid analysis determined that there were twenty-two identifiable fatty acids found in the different cuts. The omega-3 fatty acids eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) with DHA being present at a higher amount than EPA in each cut. Overall, there are similarities and differences among the different cuts of bluefin tuna that researchers would need to mimic to provide adequate nutritional and sensorial properties of PBT. / Master of Science in Life Sciences / Pacific bluefin tuna (PBT; Thunnus orientalis) is a fish that has gained tremendous popularity over the years due to the globalization of Japanese cuisine. This tuna species is synonymous with high quality and great taste, making it key for sushi and sashimi dishes. The increased demand for this species has caused wild populations to decrease; therefore, the food industry has sought to create meat alternatives for the species. The PBT has 6 distinct cuts that make up the composition of the fish, similar to the differences that can be found in beef cuts. These 6 distinct cuts are otoro, ventral akami, dorsal akami, ventral chu-toro, dorsal chu-toro, and wakaremi. The purpose of this study is to determine the aroma composition, fatty acid composition, and fat, moisture, ash, and protein contents of the different cuts. To measure the aroma composition, gas-chromatography mass spectroscopy (GC-MS) was used; it is a machine that can be used to identify and measure the aroma compounds of products. Standard procedures were used for the other analyses. Overall, 41 aroma compounds were identified in PBT that met the identification criteria, consisting of aldehydes, alcohols, alkanes, ketones, alkenes, aromatic compounds, and some miscellaneous compounds. The cuts displayed distinguishable differences in their fat, ash, moisture, and protein contents. The fatty acid analysis concluded that there were twenty-two identifiable fatty acids found in the different cuts. In this study, close attention was paid to omega-3 fatty acids due to their health benefits for consumers. The omega-3 fatty acids eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) were found in all cuts with DHA being present at a higher amount than EPA in each cut. From this study, researchers have the foundation for understanding the composition of PBT to create a meat alternative that meets consumer expectations.

The reliable measurement of growth and condition is vital for effective fisheries assessments. Biologists have long attempted to estimate condition for their assessments, but a reliable method to nonlethally estimate body composition is lacking. Proximate analysis is the most dependable and accurate method for estimating internal composition, but it is lethal, time consuming, and expensive. Recent research has shown bioelectrical impedance analysis (BIA) to be an effective method for estimating proximate composition in some fishes. The technique is quick, inexpensive, and, most importantly, nonlethal, which is vital when examining endangered species or cultured fish. My research focused on developing BIA indices for several new species of fish, using those indices to evaluate the body composition of fish in the field, and determining whether water temperature influenced resistance and reactance measurements. I found that BIA accurately estimated the body composition of bluegill Lepomis macrochirus, redear sunfish Lepomis microlophus, brook trout Salvelinus fontinalis, and northern logperch Percina caprodes (r2 ≥ 0.71, p < 0.0001). I also determined that bluegill and redear regressions were not significantly different (P ≥ 0.10) suggesting they can be used interchangeably during future studies. Laboratory studies revealed that water temperature did not significantly influence resistance and reactance measurements of bluegill, redear, and largemouth bass Micropterus salmoides (P ≥ 0.18). These results, along with previous literature, indicate that BIA may be an accurate and reliable assessment tool for fisheries biologists. / Master of Science

La conception de la mémoire adaptative défend l’idée selon laquelle la mémoire humaine a évolué, pendant toute l’histoire de l’Homme, de sorte à résoudre des problèmes adaptatifs spécifiques (e.g., trouver de la nourriture, se protéger des prédateurs). De nombreuses recherches soutiennent cette conception en montrant, par exemple, que nous mémorisons mieux les informations quand nous les traitons relativement à notre propre survie (Nairne, Thompson, & Pandeirada, 2007). Récemment, un nouvel effet mnésique est venu renforcer cette approche fonctionnelle de la mémoire : l’effet animé. Il correspond à une meilleure mémorisation des entités animées (entités vivantes, capables de se déplacer de façon autonome, e.g., bébé, sauterelle) comparativement aux entités inanimées (entités non vivantes, e.g., bouilloire, corde). Cet effet serait dû à la plus grande importance des entités animées que de celle inanimées pour la survie et/ou la reproduction. Traiter ces entités de façon privilégiée a été primordiale pour la survie de nos ancêtres, et en conséquence, pour l’évolution de l’espèce humaine. Dans ce travail de thèse, nous nous sommes focalisés sur l'effet animé en mémoire épisodique afin de mieux comprendre les mécanismes proximaux qui le sous-tendent et ses conditions d’apparition. Ainsi nos principaux résultats ont-ils permis d’établir que l’effet animé en mémoire est : (1) lié au processus de remémoration (rappel conscient de détails contextuels) ; (2) indépendant des ressources cognitives disponibles ; (3) en partie sous tendu par de l’imagerie mentale et (4) modérément modulé par le contexte d’encodage. / According to the adaptive memory view, human memory was shaped in the distant past to remember fitness relevant information (e.g., finding food, protecting ourselves from predators). An increasing number of studies favor this view, by showing that information related to to survival is memorized better than information not related to survival (Nairne, Thompson, & Pandeirada, 2007). Recently, a new type of findings further supports this functional approach of memory: animacy effects, that is to say the observation that animates (living things able of independent movements; e.g., baby, grasshopper) are remembered better than inanimates (non-living things e.g., teakettle, rope). One account of this memory effect has been that animates are of greater importance for survival and/or reproduction. In effect, knowing how to interact with animates was crucial for the survival of our ancestors, and thus, for the evolution of our species. In this work, our main purposes were to identify some proximate mechanisms underpinning animacy effects in episodic memory as well as the contexts in which these effects are observed. Taken overall, our findings accord with the claim that animacy effects in memory are: (1) linked to recollection (conscious recall of contextual details); (2) independent of cognitive resources; (3) partially underpinned by mental imagery and (4) to some extent modulated by encoding context.

Rockfish are commercially and recreationally important, yet due to the in habitat depths at which rockfish inhabit, little is known about their ecology. As a consequence, management of rockfish population as a fishery resource is a work in progress. In particular, changes in physiological condition aver the course of the year is poorly described. This study examined 19 different species of Sebastes from the Southern California Bight over four seasons (late summer, fall, winter, and spring) using metabolic enzyme assays. Enzymes used were lactate dehydrogenase (LDH), malate dehydrogenase (MDH), pyruvate kinase (PK), and citrate synthase (CS). Some muscle composition data (percent water, percent protein, percent lipid, and protein as a percentage of wet mass) were also used to help interpret the enzyme data. Enzyme activity was lowest in the summer when expressed as activity per gram wet weight but when it was expressed per gram protein the trend was reversed. We found that the rockfish tend to have the highest protein as a percentage of wet mass (P%WM) in the spring right before the upwelling period begins and have the lowest P%WM in late summer after the peak of upwelling. Their metabolic poise (represented as CS/LDH) grouped according to locomotory habit (benthic or bentho-pelagic). A mass and oxygen consumption plot also showed that the species group according to locomotory habit. With those known to be benthic grouped together and those species that are known to more actively swimming had higher values. This knowledge could be used to infer whether a rockfish that hasn't been well studied is benthic or bentho-pelagic.

A decline in Human Immunodeficiency Virus (HIV) prevalence rates have been observed among females ages 15 to 19 years and 20 to 24 years in Zimbabwe between 2005 and 2010. However, for males 15 to 19 years, rising trends were observed, whereas for males ages 20 to 24 years, rates fluctuated between 2005 and 2011. The purpose of this cross-sectional study was to examine relationships between sexual behaviors and practices and HIV prevalence among young males and females ages 15 to 24 years in Zimbabwe. Guided by constructs of proximate determinants framework, extracted data from two National Demographic Health surveys of 2005/06 and 2010/11 were analyzed using chi square and binary logistic regression. This study revealed that sexual practices, relationship status, and education status increase the odds of being HIV positive differently among 15 to 19-year-olds and 20 to 24-year-olds based on gender and changes through time. Significant relationship existed between HIV positive serostatus and total number of life time partners among females 15 to 19 years and 20 to 24 years; lack of condom use among males 20 to 24 years in 2005/06; early sexual debut and lower education status among females 20 to 24 years; and being widowed, separated, or divorced among males and females 20 to 24 years in 2010/11. The Odds of being HIV positive for males ages 15 to 19 years was not predicted by sexual practice, creating a need for future study. This study can contribute to positive social change by providing information about the associations between HIV serostatus and the assessed risk factors, which may help promote awareness about HIV infection risk, thereby helping develop and implement targeted public health interventions to reduce the burden of HIV.

Mutton meat was tested in different products in order to obtain prototype products in which mutton can effectively be used without the objectionable mutton off flavor. Mutton flavor reduction was achieved in the processed meat products by: (a) lowering mutton fat to a level of 10% or less, (b) using spices, smoking and/or curing, (c) substituting fat from beef or pork for mutton fat, and (d) the action of microbial starter cultures. Four taste panel sessions were set up to rate these products against an all beef or all pork control for consumer acceptability. Taste panel results indicate that flavor had the greatest effect on overall acceptability of these products, compared to texture and appearance. Proximate meat analysis for fat, protein, moisture and ash were performed using the Technicon InfraAlyzer 400R and the results were compared with values obtained by reference AOAC methods. Correlation coefficients of 0.992, 0.867, 0.992 and 0.511 were obtained for fat, protein, moisture and ash respectively. The two methods were not significantly different (p = .05). These results indicate that the InfraAlyzer may be used as a rapid method for proximate analysis of fat, protein and moisture.