There are two main goals of this thesis: to investigate the flow-induced crystallization behaviour of Polybutene-1 (PB-1 samples, and to study the effects of molecular parameters on the crystallization behaviour While flow-induced crystallization is not a new area in polymer research, well-defined experimental methods that allow access to high flow rate range comparable to that encountered in real processing are still lacking. Two types of flow are considered: shear and uniaxial elongational. Regarding the second aim, several molecular parameters considered are: molecular weight, molecular weight distribution, isotacticity, presence of nucleating agents, and copolymer content. For this purpose an array of PB-1 samples were used. It is found that each of these parameters can have significant effect on the crystallization behaviour. Mainly rheological methods were utilized to conduct the flow-induced crystallization experiments. Crystallization onset time is define d from the change in viscosity or other related parameters. The experiments begin with low shear rate range, to ensure that the results are comparable with literature data. In this range we encounter the quasi-quiescent onset time at very small. shear rates, which draws an interesting comparison with another physical parameter, the gel time. Beyond a critical flow rate a decrease in the onset time is seen, and a plateau-and-slope trend is evident for a curve of onset time vs. shear rate. Using a combination of three experimental methods, shear rates ranging from Q0001 - 500 s-1 are successfully achieved, and a good agreement between these methods is observed. Furthermore, a normalization procedure is introduced, which yields temperature-invariant curves for the mentioned range of shear rate. For the uniaxial elongation flow, the Elongational Viscosity Fixture (EVF) is employed, with the strain rate ranging from 0.0001 - 10 s'. A greater reduction in onset time as compared to shear (at the same shear/strain r ate) is observed, and the difference in the onset times for shear and elongation already reaches more than one decade for a flow rate of 10 5. This quantitative comparison is particularly important; since not so many data on elongation-induced crystallization are available in the literature. Finally, the thesis compares several flow induced crystallization models that can be useful as prediction tools and selects one of these models to be compared with the experimental data. A qualitative agreement is found, however, for better quantitative prediction the model still needs to be.

Résumé : Cette thèse vise à documenter les processus physiques et dynamiques associés à la circulation de mousson vietnamienne d'échelles régionale et synoptique, afin d'étudier la prévisibilité de ses principales composantes et de mettre en place des méthodes statisticodynamiques de prévision des pluies de l'échelle saisonnière à celle des événements. Elle s'articule en deux parties. La première partie est, en fait, une étude climatique fondée sur l'analyse diagnostique des données : - d'abord, les données stationnelles des pluies et des températures mensuelles sur la période 1960-2000 sont utilisées pour analyser le cycle moyen et la variabilité interannuelle de ces champs sur les sept régions climatiques traditionnelles du Vietnam, à l'aide des précipitations observées en diverses stations. Des classifications et des corrélations sont appliquées sur les données de pluies afin de définir les sous-régions sur lesquelles seront calculés des indices spatiaux pour analyser les chroniques d'évolution et définir les prédictants et prédicteurs pour la seconde partie ; - ensuite, les données atmosphériques de réanalyse du NCEP/DOE2 et les estimations pluviométriques du CMAP sur la période 1979-2004 en 2.5° x 2.5° sont utilisées pour décrire les processus de base, le cycle annuel moyen et la variabilité de la mousson dans la gamme des pas de temps synoptiques à interannuel. La seconde partie est une étude de prévisibilité des précipitations saisonnières : - les données de pluie in situ et le vent à 1 000 hPa sont utilisés pour définir l'onset de pluie sur le sud et nord Vietnam. Les dates d'onset sont prévues en se basant sur les indices régionaux qui sont sélectionnées à partir de données NCEP/DOE2 ; - la prévisibilité des cumuls saisonniers de pluies est enfin définie par la double utilisation de cinq modèles couplés du programme européen ENSEMBLES et par la prévision statistique.

<p>The aim of this study is to examine the vocabulary and receptive collocation knowledge in English among Swedish upper secondary school students. The primary material consists of two vocabulary tests, one collocation test, and a background questionnaire.</p><p>The first research question concerns whether the students who receive a major part of their education in English have a higher level of vocabulary and receptive collocation knowledge in English than those who are taught primarily in Swedish. The second concerns if the students who started to learn English before the age of 7 have a higher level of vocabulary and receptive collocation knowledge in English than those who started after 7. The third concerns if the level of the students' vocabulary and receptive collocation knowledge correlates. The fourth addresses whether external inputs of English may have had an effect on the students' vocabulary and receptive collocation knowledge level.</p><p>The results indicate that reinforcement of English through an education mostly in English has rendered a higher level of vocabulary and receptive collocation knowledge in English. In addition, starting to learn English before age 7 also appeared to have had a positive effect on these levels. In addition, the results suggest that an early onset (before 7) of English compensates for lack of reinforcement of English. Conversely, reinforcement of English compensates for a late onset (after 7) of English. However, the results imply that the combination of an early onset (before 7) of English and reinforcement of English is the most efficient means to achieve a high level of vocabulary and receptive collocation knowledge.</p><p>Moreover, a clear correlation was found between vocabulary knowledge and receptive collocation knowledge, which also points to the importance of a large exposure to English.</p><p>For the high performance students, external influences such as English in primary and secondary school, and a high motivation to learn English may have contributed to a higher language confidence, and possibly a higher level of vocabulary and receptive collocation knowledge.</p><p> </p>

<p>Voice onset time (VOT) är en akustisk tidsparameter som speglar den talmotoriska kontrollen. VOT anses vara det mest tillförlitliga akustiska tecknet på om en klusil är tonande eller tonlös.</p><p>Syfte: att undersöka och jämföra VOT hos barn i åldrarna 3, 4 och 5 år samt jämföra med tidigare publicerade svenska vuxenvärden.</p><p>Metod: 83 barn (51 flickor; 32 pojkar) ljudinspelades vid produktion av minimala par för de svenska klusilerna.</p><p>Resultat: medelvärden för VOT minskade genomgående med åldern. Signifikanta skillnader erhölls mellan 3- och 5-åringarna för ljuden /t k b g/ samt gällande användandet av förton för tonande klusiler. Jämförelser med vuxenvärden visade att vuxna i högre utsträckning hade förton för de tonande ljuden och kortare VOT för de tonlösa ljuden än de, i föreliggande studie, deltagande barnen. Inga signifikanta könsskillnader påträffades.</p><p>Resultaten av föreliggande studie kan användas som referensmaterial vid bedömning av barn med talmotoriska störningar.<em></em></p>

<p>The goal of this research study was to do an explorative study in order to establish the experiences of patients with regard to social and health services factors that contribute to delays in seeking treatment for Tuberculosis.</p>

Voice onset time (VOT) är en akustisk tidsparameter som speglar den talmotoriska kontrollen. VOT anses vara det mest tillförlitliga akustiska tecknet på om en klusil är tonande eller tonlös. Syfte: att undersöka och jämföra VOT hos barn i åldrarna 3, 4 och 5 år samt jämföra med tidigare publicerade svenska vuxenvärden. Metod: 83 barn (51 flickor; 32 pojkar) ljudinspelades vid produktion av minimala par för de svenska klusilerna. Resultat: medelvärden för VOT minskade genomgående med åldern. Signifikanta skillnader erhölls mellan 3- och 5-åringarna för ljuden /t k b g/ samt gällande användandet av förton för tonande klusiler. Jämförelser med vuxenvärden visade att vuxna i högre utsträckning hade förton för de tonande ljuden och kortare VOT för de tonlösa ljuden än de, i föreliggande studie, deltagande barnen. Inga signifikanta könsskillnader påträffades. Resultaten av föreliggande studie kan användas som referensmaterial vid bedömning av barn med talmotoriska störningar.

Ulcerative colitis is a chronic inflammatory disease that mainly affects the colon and rectum. Onset of disease is most common between the ages of 15-35 years. There is an observed increased risk of colorectal cancer associated with the disease. The risk is often described to be 2% after 10 years, 8% after 20 years and 18% after 30 years disease. Since 1977, all known patients with ulcerative colitis in the catchment area of Örnsköldsvik Hospital have been invited to attend a colonoscopic surveillance programme. At endpoint of the studies included in this thesis there were 214 patients that had attended the surveillance programme. The aims of these studies have been to evaluate the efficiency of the surveillance programme, analyse the impact of findings of DNA aneuploidy, and determine the outcome for patients that underwent limited resections instead of complete proctocolectomy. Further, we have studied the long-term outcome for patients who had an early onset of disease and analysed the expression of cytokeratin 7 and 20 in respect to findings of dysplasia, DNA aneuploidy and colorectal cancer. At the end of the studies the prevalence for ulcerative colitis was 261/100 000 and the incidence rate was 7.6/100 000/year. During the period 1977-2005, four patients died of ulcerative colitis. Nine colorectal cancers were diagnosed in eight patients, one of whom died of the cancer. Fifty-two patients had findings of dysplasia and five of these patients developed colorectal cancer. In the subgroup of patients studied (N= 147) for DNA aneuploidy, 20 were found to have specimens with DNA aneuploidy on at least one occasion. The sensitivity of aneuploidy for development of dysplasia (LGD or higher) was found to be 0.50 and the specificity 0.94. The investigation of the outcome for the patients that underwent limited resections of the colon or rectum showed that none of the patients under surveillance died of colorectal cancer or metachronous cancer in their remaining colon or rectum. A separate study concerning early onset of ulcerative colitis revealed no particular increased risk of colorectal cancer in this cohort but a fairly high incidence of primary sclerosing cholangitis was seen. In the analyses of cytokeratins it was found that 7 out of 10 patients with low-grade dysplasia and 3 of 6 with high-grade dysplasia were positive for CK7. Our results indicate a possible relationship between the expression of CK7 and CK20 and neoplastic development of colorectal mucosa in patients with ulcerative colitis. The studies on which this thesis is based, were performed on a relatively small number of patients, however the time of observation was long and, most importantly, the patients were from a well defined catchment area. We conclude that the surveillance programme has been efficient in minimising the risk of lethal colorectal cancer. Analysing DNA ploidy helps to target the patients that need more attention but the method cannot stand alone. Our study on cytokeratins points to a relationship between dysplasia and CK7 but the results are preliminary and further studies needs to be done. We have shown that it is safe to do a limited colorectal resection in respect to lethal colorectal cancer. Early onset of ulcerative colitis as a risk factor for colorectal cancer was not found in the group we have studied, which could be due to effective surveillance and/or medication. A fairly high operation rate in this group may also have contributed. The most important variable in the beneficial outcome regarding lethal colorectal cancer in these studies is, in our opinion, the outstanding compliance of the patients to the colonoscopic surveillance programme.

The increasing prevalence of allergic diseases in affluent societies has been associated with changes in microbial exposure early in life and a less diverse gut flora. The objective of this thesis was to assess the development of allergic sensitisation and symptoms during the first four years of life in a non-selected birth cohort in relation to environmental factors, family history, gut microbiota and salivary IgA antibodies. The cohort comprised all 1,228 infants living in a Swedish county who were born over a one-year period. The parents replied to questionnaires, and 817 children (67 %) were skin prick tested both at 1 and 4 years of age. Saliva (n=279), faecal (n=139) and blood (n=253) samples were collected at 1 year of age from children with a positive skin prick test at 1 year and from a sample of children with a negative skin prick test. Faecal samples were also obtained from 53 children at 4 years of age. Dog keeping during infancy was associated with a decreased risk of sensitisation to pollen and late-onset wheezing at age 4, and the reduced odds ratios persisted after adjustment for heredity and avoidance measures, OR 0.3, 95% CI 0.1-0.9 and OR 0.5, 95% CI 0.2-1.0, respectively. In contrast, early dog keeping was associated with an increased risk of earlyonset transient wheezing but only in children with parental asthma (OR 2,8, 95% CI 1.3-6.4). Levels of short chain fatty acids (SCFAs) in faeces were assessed both at 1 and 4 years of age and related to the development of sensitisation and symptoms. The levels of acetic (p&lt;.01) and propionic (p&lt;.01) acids decreased from one to four years of age, whereas valeric acid (p&lt;.001) increased which is in line with a more complex gut microbiota with age. Allergic children, compared with non-allergic children, had lower levels of i-butyric, i-valeric and valeric acid in faeces both at 1 and 4 years of age. Low levels of secretory IgA (SIgA) in saliva were associated with wheezing but only in sensitised children. In children with positive SPT to at least one allergen both at 1 and 4 years of age and in children with circulating IgE antibodies to egg or cat at one year of age, those who developed late-onset wheezing had lower levels of SIgA than those who did not, p=.04 and p=.02 respectively. Of 9 children with levels of SIgA in the upper quartile and persistent sensitisation, none developed wheezing, compared with 10/20 children with lower levels, (p=. 01). Having older siblings, more than three infections during infancy, at least one smoking parent and male gender were all associated with high levels (in the upper quartile) of total IgA and SIgA. The findings in this thesis indicate that the microbial load early in life could affect the development of allergy. A functional assessment of the gut flora demonstrated differences between allergic and non-allergic children both at 1 and 4 years of age. Salivary IgA was associated with infections during infancy, and high levels of secretory IgA protected from symptoms in sensitised children. Finally, dog keeping in infancy may offer protection from allergy, but the mechanism is uncertain.

This study compares lifetime prevalence and age of first use (onset) for alcohol, cannabis, and other drugs in six international sites. Data from seven epidemiologic field surveys that used compatible instruments and study designs were compiled for cross-site analyses by the International Consortium of Psychiatric Epidemiology (ICPE). The world health organization’s composite international diagnostic instrument (WHO-CIDI) and additional items were used to ascertain drug use in each site. Lifetime use rates were estimated for alcohol, cannabis, and other illicit drugs. Survival analyses were used to estimate age of onset. Study settings and main results: use of alcohol twelve or more times ranged in descending order from the Netherlands (86.3%), United States (71.7%), Ontario, Canada (71.6%); São Paulo, Brazil (66.1%), Munich, Germany (64.9%), Fresno, California (USA) (51.9%), to Mexico City (43.2%). Use of cannabis five or more times in a lifetime ranged from 28.8 in the United States to 1.7% in Mexico City, and other drugs ranged from United States (19.4%) to Mexico City (1.7%). Age of first use was similar across study sites. This study demonstrates the fundamental uniformity of onset patterns by age as contrasted with wide variations in lifetime prevalences across sites. Study findings suggest that drug use patterns may change among emigrating populations from low consumption nations as a consequence of international resettlement in nations with higher rates. Methodological limitations of the study along with recommendations for future international comparative research are discussed.

BACKGROUND: Sleep problems affect people of all ages, race, gender, and socioeconomic classifications. Undiagnosed sleep disorders significantly and adversely impact a person’s level of academic achievement, job performance, and subsequently, socioeconomic status. Undiagnosed sleep disorders also negatively impact both direct and indirect costs for employers, the national government, and the general public. Sleepiness has significant implications on quality of life by impacting occupational performance, driving ability, cognition, memory, and overall health. The purpose of this study is to describe the prevalence of daytime sleepiness, as well as other quantitative predictors of sleep continuity and quality. METHODS: Population data from the CDC program in fatigue surveillance were used for this secondary analysis seeking to characterize sleep quality and continuity variables. Each participant underwent a standard nocturnal polysomnography and a standard multiple sleep latency test (MSLT) on the subsequent day. Frequency and chi-square tests were used to describe the sample. One-Way Analysis of Variance (ANOVA) was used to compare sleep related variables of groups with sleep latencies of <5 >minutes, 5-10 minutes, and >10 minutes. Bivariate and multivariate logistic regression was used to examine the association of the sleep variables with sleep latency time. RESULTS: The mean (SD) sleep latency of the sample was 8.8 (4.9) minutes. Twenty-four individuals had ≥1 SOREM, and approximately 50% of participants (n = 100) met clinical criteria for a sleep disorder. Individuals with shorter sleep latencies, compared to those with longer latencies reported higher levels of subjective sleepiness, had higher sleep efficiency percentages, and longer sleep times. The Epworth Sleepiness Scale, sleep efficiency percentage, total sleep time, the presence of a sleep disorder, and limb movement index were positively associated with a mean sleep latency of <5 >minutes. CONCLUSIONS: The presence of a significant percentage of sleep disorders within our study sample validate prior suggestions that such disorders remain unrecognized, undiagnosed, and untreated. In addition, our findings confirm questionnaire-based surveys that suggest a significant number of the population is excessively sleepy, or hypersomnolent. Therefore, the high prevalence of sleep disorders and the negative public health effects of daytime sleepiness demand attention. Further studies are now required to better quantify levels daytime sleepiness, within a population based sample, to better understand their impact upon morbidity and mortality. This will not only expand on our current understanding of daytime sleepiness, but it will also raise awareness surrounding its significance and relation to public health.