Exchange Effects and CIDEP

Väitöskirjassa on tutkittu tilastollisen koesuunnittelun teoriaa. Koesuunnittelua tarvitaan, kun tilastollisiin mittauksiin on käytettävissä vain rajallinen määrä resursseja mutta samalla kuitenkin halutaan luotettavaa tietoa. Tutkimuksen kolmessa ensimmäisessä artikkelissa on kehitetty koesuunnitelmia satunnaiskertoimisille regressiomalleille. Malleja voidaan soveltaa, kun tehdään usealle yksilölle peräkkäisiä mittauksia, esimerkiksi eri aikapisteissä. Väitöskirjan artikkeleissa sovelluskohteena ovat olleet puiden rungot, joista on mitattu läpimittoja eri korkeuksilla. Kutakin yksilöä, tässä tapauksessa puunrunkoa, vastaavat omat regressiomallin kertoimet. Koesuunnitelma käsittää tiedon siitä, miten mittausten määrä jakaantuu eri yksilöiden välillä ja yksilöiden sisäisesti. Tavoitteena on joko arvioida mallin keskimääräiset parametrit mahdollisimman tarkasti tai ennustaa uusia havaintoarvoja. Ensimmäisessä artikkelissa on ennustealue on sama kuin havaintoväli ja toisessa se on havaintovälin ulkopuolella. Kolmannessa artikkelissa on esillä käänteisennusteongelma, kun halutaan arvioida pistettä, jossa vastemuuttuja, esim. puun läpimitta, saavuttaa tietyn tason. Koesuunnitelmia vertaillaan keskenään käyttämällä erilaisia optimaalisuuskriteereitä. Kolmannessa ja neljännessä väitöskirjan artikkelissa tarkastellaan DS-kriteeriä, jota on tutkittu vain vähän tähän mennessä. DS-kriteeri on siinä mielessä yleinen, että koesuunnitelman ollessa DS-optimaalinen se on optimaalinen myös monen perinteisen optimaalisuuskriteerin suhteen. Yleensä DS-optimaalista suunnitelmaa ei ole olemassa, mutta suunnitelmia voidaan parantaa DS-kriteerin suhteen. Tutkimuksessa on rajoituttu yksinkertaisiin polynomimalleihin, joten lisätutkimus on tarpeen DS-kriteerin käytöstä laajemmissa yhteyksissä.The thesis consists of five papers and a summary. It has two main themes in the area of experimental design. Firstly, optimal designs for estimation, prediction and inverse prediction are developed in random coefficient linear regression models. Mainly first-degree models are dealt with. The results can be applied in repeated measurements situations. Secondly, a relatively new design criterion, the distance optimality criterion, is introduced. Its properties are studied and some results in estimation and prediction problems deduced. The criterion can be used to find optimal designs or to improve designs in polynomial regression models. It has interesting relations to traditional D- and E-optimality criteria

Serological Survey and Pathogen Exposure of Adult Female White-tailed Deer in the Western Dakotas

Establishing baseline values for pathogen exposure and nutritional indices is necessary to monitor population health. However, little is known about white-tailed deer (Odocoileus virginianus) pathogen exposure and nutritional condition in the Northern Great Plains. Our objective was to assess pathogen exposure and establish nutritional indices for female white-tailed deer in Dunn and Grant counties, North Dakota and Perkins County, South Dakota. During 2014, we collected blood serum from 150 adult female white-tailed deer. Pathogens with the highest antibody prevalence included West Nile Virus (WNV; 85%), epizootic hemorrhagic disease (48%), and malignant catarrhal fever (32%). Serum values for creatine kinase, globulin, glucose, potassium, and lactate dehydrogenase in all three study areas were higher than reference ranges while sodium was low in Grant County relative to Dunn and Perkins counties. We speculate that high exposure of WNV and high potassium values combined with low sodium values may affect neonate survival in Grant County. However, regional differences in pathogen exposure, their connection to serum values, and their potential interactive effects on survival are not well understood

Habitat Selection of White-tailed Deer Fawns and their Dams in the Northern Great Plains

Habitat availability can affect important life-history traits such as survival; however, little information exists on how microhabitat characteristics found at parturition sites selected by dams and bed sites selected by their offspring differ fromthe surrounding area and from each other. Therefore, we assessed how vegetation affected maternal parturition and offspring bed site selection for white-tailed deer (Odocoileus virginianus) in the Northern Great Plains. Dams selected for sites with decreased vegetation height, potentially improving their visibility, which may increase their ability to escape approaching predators. Conversely, there was no variation between vegetative characteristics at neonate bed sites and their associated random sites, indicating grasslands provide adequate concealment for neonates. Dams possess the ability to flee from approaching predators, thus increasing the importance of visibility while giving birth. Conversely, neonates depend on fear bradycardia as their main antipredator defense, so concealment is more important. Our results suggest that vegetation structure is an important characteristic to white-tailed deer as habitat needs vary between adults and neonates

Serological Survey and Pathogen Exposure of Adult Female White-tailed Deer in the Western Dakotas

Establishing baseline values for pathogen exposure and nutritional indices is necessary to monitor population health. However, little is known about white-tailed deer (Odocoileus virginianus) pathogen exposure and nutritional condition in the Northern Great Plains. Our objective was to assess pathogen exposure and establish nutritional indices for female white-tailed deer in Dunn and Grant counties, North Dakota and Perkins County, South Dakota. During 2014, we collected blood serum from 150 adult female white-tailed deer. Pathogens with the highest antibody prevalence included West Nile Virus (WNV; 85%), epizootic hemorrhagic disease (48%), and malignant catarrhal fever (32%). Serum values for creatine kinase, globulin, glucose, potassium, and lactate dehydrogenase in all three study areas were higher than reference ranges while sodium was low in Grant County relative to Dunn and Perkins counties. We speculate that high exposure of WNV and high potassium values combined with low sodium values may affect neonate survival in Grant County. However, regional differences in pathogen exposure, their connection to serum values, and their potential interactive effects on survival are not well understood