Casting new light on the chronology of the loess/paleosol sequences in Lower Austria

Der vorliegende Artikel gibt einen Überblick über neu datierte Abschnitte in bekannten Löss/Paläoboden-Sequenzen Niederösterreichs. Die Ergebnisse der Datierungen im Profil Joching deuten darauf hin, dass es im letzten Hochglazial zur Lösssedimentation kam. Die meisten erfassten Alter sind jedoch älter als das letzte Hochglazial, was auf Erosionsprozesse hindeutet, die zur Abtragung der jüngeren Lösse geführt hat. In dem Abschnitt zwischen ~28 ka and ~35 ka wurden überwiegend Tundragleye gebildet. Eine intensivere interstadiale Bodenbildung ist nicht nachzuweisen. Dieses Ergebnis kann auch für die stratigraphische Einstufung von ‚Stillfried B‘ (sensu Fink) von Bedeutung sein. Der folgende chronologische Abschnitt liegt zwischen ~35 ka and ~57 ka in Lösssedimenten mit eingeschalteten Tundragleyen. Auch dieser Abschnitt ist durch Umlagerungsprozesse charakterisiert. Im Zeitraum von ~57 ka bis ~106 ka befindet sich eine markante Zeitlücke, die vermutlich auf langandauernde und intensive Erosionsprozesse im Untersuchungsgebiet zurückzuführen ist. Die älteste Datierung in den Sedimenten des letzten Glazials mit 106 ± 12 ka befindet sich in Paudorf direkt über dem ‚Stillfried A‘- Komplex (Paudorfer Bodenbildung). Direkt unter diesem Pedokomplex, bzw. vergleichbaren Pedokomplexen treten in Lössablagerungen Alter von 124 ± 2 5 ka (Göttweig-Aigen), 159 ± 20 ka (Paudorf 1), and 170 ± 16 ka (Joching) auf. Darüber hinausgehende Alter konnten in Stratzing, Paudorf 2, Göttweig-Furth und Langenlois nachgewiesen werden

Eating your words: constructing food and eating practices in mealtime conversation

This thesis examines the construction and action of food evaluations in mealtime conversation. It takes a social constructionist approach to eating, arguing that `talking food' is inseparable from, and thus constructive of, the practices around food and drink consumption. This challenges current psychological thinking on eating, which is typically based on a cognitive-experimental model of attitudes and intentions to eat. I argue that this does not adequately take into account the social nature of food and the way in which food and eating is embedded in everyday interaction. The thesis examines instances of family mealtimes, as a way of looking at food in interaction. Data is taken from the tape-recorded conversations during these interactions. Conversation analytic and discursive psychological approaches were used to analyse the data corpus, with a focus on participants' usage of food and drink evaluations. These evaluations were examined as part of the situated activities of the meal such as offering or requesting food, and justifying eating habits. The analysis looks at different types of food evaluations: those that are associatedw ith the food and those associated with the person evaluating the food. These types are seen to be specific to either items or categories of food, and are rhetorically designed to counter challenges. Finally, the analysis considers how embodied eating sensations such as `gustatory pleasure' are constructed through evaluative expressions. It is argued that food and drink evaluations cannot be treated as separate mental or physical states (such as food attitudes or preferences) as they are bound up with the structure of interaction at the micro-level of speaker turn organisation. Instead, food evaluations can be regarded as part of, and as constructing, the practice of eating as well as contributing to our notions of food sensations and individual taste. The analysis and approach taken in this thesis therefore suggest that we need to reconceptualise eating and consumption in terms of discursive activities in interaction

Exposure to Diesel Particulates and their Health Effects on Employees in a Metalliferous Mine in Western Australia

Diesel Particulates (DP) is a growing concern in many industries. This research looks at acute health effects related to DP exposure and how DP is monitored in an underground mine in Western Australia. Results appear to show that higher exposure to DP may in fact be linked to certain acute health issues and that a standardised method of monitoring should be developed. This research provides a basis for further DP related studies

Caracterização cinética e estrutural do sintase do óxido nítrico de Leishmania infantum

Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2012A leishmaniose é uma doença que ameaça cerca de 350 milhões de pessoas a nível mundial. O tipo mais grave da doença é a leishmaniose visceral, causada pelo parasita Leishmania infantum, com incidência na bacia do Mediterrâneo e América latina. Não existem ainda vacinas humanas nem tratamentos eficazes para a leishmaniose, o controlo desta doença é insuficiente e a área afectada pelo parasita tem aumentado. Consequentemente, a identificação de novos alvos terapêuticos eficazes assume uma elevada importância. Este projecto teve como principal objectivo caracterizar o sintase do óxido nítrico (NOS) de Leishmania infantum a nível estrutural, funcional e cinético ao longo do ciclo de vida do parasita, e o seu potencial como alvo terapêutico dada a relevância deste enzima em processos celulares vitais. Demonstrou-se pela primeira vez a presença de um NOS constitutivo dependente do cálcio activo nos diferentes estadios do ciclo de vida de Leishmania infantum. Foi descoberto que a sua actividade é regulada pelo cofactor tetrahidrobiopterina (BH4). Apesar da expressão do NOS não variar entre promastigotas e amastigotas, observou-se que a actividade do enzima é mais elevada em promastigotas em fase exponencial de crescimento do que em promastigotas em estado estacionário e amastigotas, evidenciando assim que o NO endógeno desempenha um importante papel importante na infectividade dos parasitas. Após otimização das condições de produção de NOS recombinante, elucidou-se pela primeira vez a estrutura quaternária do NOS de um tripanosomatídeo. O NOS de Leishmania infantum é um homotetrâmero enquanto os NOS de mamíferossão homodímeros. Observou-se ainda que o enzima do parasita não necessita de cofactores para formação da estrutura quaternária, sendo no entanto estabilizado pela ligação do heme e do BH4. Este enzima é destabilizado termicamente e por exposição ao NO, similarmente ao enzima de mamíferos. As diferenças estruturais e de sequência entre o NOS do parasita e as isoformas de mamíferos sugerem que este enzima seja um potencial alvo terapêutico em tripanosomatideos.Leishmaniasis is a disease that threatens 350 million people worldwide. The most serious type of the disease is the visceral leishmaniasis, caused by Leishmania infantum in the Mediterranean sea and Latin America. There are no human vaccines nor efficient treatment methods for the disease, the control of the infected animals is inefficient, and the area affected by the parasite is expanding. Therefore, the discovery of new therapeutic targets is extremely important. Our aim was to characterize kinetic, functional and structurally the nitric oxide synthase (NOS) from Leishmania infantum, during the parasite’s life cicle, accessing the potential of the NOS as a therapeutic target, due to its great importance for the cell. We showed for the first time the existence of a calcium-dependent constitutive NOS, which is active during the different stages of Leishmania infantum’s life cycle. This enzyme´s activity is regulated by the cofactor BH4, and its expression does not change between promastigotes and amastigotes. However, we showed that its activity is higher in exponential growth phase promastigotes than in stationary phase promastigotes and amastigotes. This way, it was shown that endogenous NO is important for parasite’s infectivity. After optimization of the recombinant enzyme production, we unveiled for the first time the quaternary structure of a NOS from a trypanosomatid. The NOS from Leishmania infantum is homotetrameric, while the mammalian NOS are homodimers. It was also observed that the parasite’s NOS does not need the presence of cofactors for the assembly of the quaternary structure. However, it is stabilized by the ligation of the heme group and tetrahydrobiopterin (BH4), and destabilized by high temperature and NO, similarly to the mammalian enzymes. The differences regarding the structure and sequence of the parasite’s and mammalian NOS, point this enzyme as a potential therapeutic target in trypanosomatids

Hartloosheid en klemhart bij bloemkool

This publication describes the occurrence of common blindness and whiptails in cauliflowers

Comparative studies in experimental hypertension and cardiac failure

The common theme of this thesis is the characterisation of cardiac and vascular hypertrophy in animal models of cardiovascular disease. The pathophysiology of hypertension, left ventricular hypertrophy and heart failure are discussed, with particular emphasis on cardiac and vascular alterations in animal models. Echocardiography was validated for use in rats, and applied to a genetic model of hypertension, the stroke-prone spontaneously hypertensive rat (SHRSP), and to the rat coronary artery ligation (CAL) model of heart failure. Likewise, laser scanning confocal microscopy (LSCM) was utilised to examine vascular remodelling in both these models. The utility of trans-thoracic echocardiography for estimating left ventricular (LV) mass was validated in lightly sedated SHRSP and WKY rats. Two-dimensional and M-mode parasternal short-axis views were readily obtainable and used to calculate LV mass using the cubed formula, which was then compared to blotted LV weight at autopsy. Left ventricular hypertrophy (LVH) was defined for this colony of rats as a LV mass-to-body weight ratio of greater than 2.86g/Kg. The accuracy of echocardiography in detecting LV hypertrophy was determined: sensitivity 92%, specificity 64%, false-positive rate 22%, and false negative rate 14%. LVH in the SHRSP was apparent as a 28% higher LV mass compared to WKY rats. The anterior wall was 23% thicker, and the posterior wall 17% thicker. Differences in systolic function were measured by ejection fraction and fractional shortening, and were found to be anaesthetic dependent, with the SHRSP being more prone to halothane-induced cardiac depression. Intra-observer variability was quantified using repeat examinations in a sub-group of 18 rats. Co-efficient of repeatability was calculated for a range of echocardiographic parameters. The most reliable measurements were myocardial cross-sectional area (15%), LV wall thickness (16%), and end diastolic dimension (18%). LV mass had a co-efficient of repeatability of 21%. The ability of antihypertensives to prevent the rise in blood pressure and associated complications of cardiac and vascular hypertrophy were examined in the SHRSP. At weeks 6-7 of age, 24 SHRSP (M:F=12:12) were assigned to three groups and given in their food either irbesartan (Irb, 16mg/kg/Day), hydrochlorothiazide + hydralazine (H+H, 4mg/kg/day of each), or control (C). Systolic blood pressure was measured twice weekly by tail cuff plythesmography, and cardiac hypertrophy quantified using echocardiography at 0, 4 and 8 weeks of treatment. LV gene expression of natriuretic peptides was assessed by Northern blot analysis. To examine the effects on vascular hypertrophy, 3rd order mesenteric resistance arteries were fixed in formalin at half systolic blood pressure, stained with propidium iodide, and imaged using LSCM. One-way ANOVA was used to compare between groups, correcting for multiple comparisons using the Newman-Keuls test. Conclusion - Heart failure was mild and well compensated in these animals. Despite this, a novel type of remodelling was observed in mesenteric resistance arteries, which could have implications for small artery function. A small study was undertaken to examine the feasibility of performing CAL in the SHRSP. Of eleven animals, six survived to 2-weeks, while only three of these, with the smallest infarcts, survived the full 8 weeks. Peri-surgical death was similar to WKY, but arrhythmic death more common. Future approaches to bring mortality within acceptable limits could include the use of anti-arrhythmic drugs or blood pressure lowering immediately after surgery. (Abstract shortened by ProQuest.)