There is a well-established connection between adult mortality and the conditions an individual is exposed to while in utero. There is a wealth of research that connects conditions such as asthma and allergies, mortality due to heart disease and diagnoses of schizophrenia to conditions during an individual?s early life and even their time in utero. The aim of this dissertation is to see if this same connection can be made to infant mortality, and further will there be any connection in contemporary cohorts? I use the Linked Birth/Infant Death dataset available from the Centers for Disease Control (CDC) for the years 2000 to 2004. This dissertation specifically uses the dependent variable "cause specific infant death" with various measures of the time the infant was born or was in utero. I undertake three multinomial logistic regression models with the dependent variable "cause specific infant death." I then proceed to a multilevel multinomial logistic regression model using state-level climate measures at the second level. I conclude with the construction of maps displaying the spatial relationship between infant mortality and climate. The first analysis uses the independent variable of interest "month of birth," the second analysis uses the independent variable of interest "months of first trimester," and the last level-one analysis uses the independent variable of interest "months of third trimester." After running all three models, I determined that the most effective independent variable of interest is "month of birth," which I use in a multilevel logistic regression model. The multilevel model uses the month of birth variable at level-one and incorporates state level measures of climate at the second level. I find that the humidity index and the temperature index are negatively associated with the month of birth variable and cause specific infant death variables, meaning that the higher these indices, the more the benefit to an infant's chances of survival. The wind index is consistently positive, meaning that the interaction of wind with cause specific infant death and month of birth is detrimental to an infant's survival. The last methods chapter shows the spatial relationship between infant mortality and climate. In this chapter I find that infant mortality in the United States is concentrated in the Southern U.S., which is also where there is a concentration of high temperature states. The connections between wind and humidity with the infant mortality rate are less consistent.

The aim of this dissertation lies in analysing the calf growth of a selected herd of meat-type cattle raised in a foothills landscape. The period of investigation lasted 5 years (2002 {--} 2006). The data obtained for the breeds Charolais and the meat-type Siemental cattle are presented in dependence on the breed, convenience of birth, mother´s height in the cross, calving month and the serial number of the birth. The study covers 795 Charolais calves and 450 calves of meat-type Siemental breed. In the time interval mentioned above, the Charolais breed gave 400 bulls and 395 heifers, the corresponding numbers for the meat-type Siemental breed are 226 bulls and 224 heifers. Considered from the viewpoint of breed influence on to the calf rate of growth, the investigation has revealed no statistically significant effect. A statistically significant effect has been revealed only for heifers 120 days old, the live weight of the meat-type Siemental heifers being higher (162,71 kg) than that for the Charolais heifers (158,14 kg). The differences in the live weight amount to 4,47 kg. Statistically, this diference is probably significant, the significance level p = 0,05. Furthermore, the work has studied the effect of calf sex onto the rate of growth in both calf categories mentioned above. The live weight of the meat-type calves show a statistically highly significant difference (p {>} 0,001) for the bulls and heifers at the age of 120, 210 and 365 days. At the age of 120 days, the live weight of bulls is by 14,31 kg higher compared with that of heifers, at the age of 210 days the difference amounts to 25,65 kg and at 365 days 116,29 kg. Similar differences between bulls and heifers are statistically highly significant also for Charolais calves. At the age of 120 days the bulls are heavier than heifers by 18,45 kg, at 210 days by 29,16 kg and at the age of 365 days this difference amounts to 115,59 kg. The study covers also the investigation of the effect of mother´s cross height on to the rate of calf growth. Considered statistically, no such effect has been revealed for calves 120, 210 and 365 days old. The investigation of the effect of the calving month has brought us to a conclusion that the heaviest calves are born in March and April, with the differences in individual months ranging on significance levels p {>} 0,001, p {>} 0,01 and p = 0,05. In both breeds we have also investigated the effect of the serial number of the birth on to the live weight. For the Charolais breed, the highest weight has been found for calves with serial number 3, 4 and 5. For the calves of the meat-type Siemental breed it has been found that the calves born as the second one reach the highest weight at the age of 120, 210 and 365 days,the results obtained being statistically highly significant (p {>} 0,001) and probably significant (p = 0,05).

Background Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. It usually strikes during young adulthood, and 2.5 million individuals are estimated to have the disease worldwide. The causes of MS are not known, but several factors have been shown to be associated with the risk of the disease, including certain genes, vitamin D, smoking and Epstein- Barr virus infection. Little is known about how/if these factors interact. Methods Study I: The risk of MS by month of birth was investigated using MS cases from the Swedish MS registry and using general population controls. Studies II–V: We identified MS cases who had donated blood prior to disease onset, and MS cases whose mothers had donated blood during pregnancy, by cross-linking a database of MS cases, and a database of mothers of MS cases, to two local biobank cohorts. One of them consisted of blood samples collected during early pregnancy, and one with samples collected during health controls. Levels of 25(OH)D (25-hydroxyvitamin D), RBP (retinol binding protein, a surrogate marker for vitamin A), CRP (C- reactive protein), cotinine (a nicotine metabolite) and anti Epstein-Barr virus nuclear antigen-1 (EBNA-1) antibodies were measured in cases and matched controls. The risk of MS by categories of these exposures was estimated in bi- and multivariable matched logistic regression models. Results Subjects born in spring had a higher risk of MS, but no influence of early gestational levels of the measured risk factors on the risk of MS in the offspring was observed. In prospective samples from MS cases and controls, 25(OH)D levels ≥75 nmol/l, intermediate RBP levels, and elevated CRP levels in young were associated with a decreased risk of MS. Elevated cotinine levels (suggestive of smoking) and high antibody reactivity against EBNA-1 were associated with an increased risk of MS. All factors but RBP were more clearly associated with MS in young subjects. Conclusion All factors analyzed in prospectively collected samples were associated with the risk of MS, and taken together, the data indicate that the key etiopathological events that lead to MS occur before the age of 20–30. Study II provides support for trials exploring the primary preventive potential of oral vitamin D supplementation.