Background: Item Response Theory is the area of psychometry that deals with the problem of constructing and analyzing psychological and sociological tests. By applying a fully Bayesian approach to this methodology, we analyze a data set obtained administering the Italian translation of the well-known Peabody Picture Vocabulary Test - Revised (PPVT-R) to a sample of Italian children. In the original English version the items are believed to be in increasing difficulty order. One main aim of this thesis is to evaluate if and how much the translation leads to violations of the increasing difficulty ordering. This aspect is important since,...
(43) - 23-oct-2012
EKWEMPE EBWEKOH, Clifford
The aim of this report was to study the effect of physical training on
maintenance and recovery of the functional muscular strength in rats injected with
Experimental Allergic Encephalomyelitis. For this effect 25 rats from different mothers
and of the same gender were randomly selected. The 25 rats were again randomly
assigned to two treatments groups. One group treated with EAE (13 rats) and the rest
assigned to the control group (12 rats). Each treatment group was subdivided into two:
swimmers and non swimmers.
The data revealed a longitudinal set up that is repeated measures were performed on each
rat over time (25 days) and to have an...
(385769 bytes; application/pdf; 35) - 05-dic-2007
Cerebral is defined as pertaining to the brain, cerebrum or intellect, and Palsy refers to
paralysis of muscle or group of muscles. Jointly, Cerebral Palsy (CP) is the term used to
describe a group of conditions with motor impairments resulting from brain damage during the
early stages of development. Cerebral palsy is non progressive and is usually not diagnosed
until a child is about 2 to 3 years of age. About 2 to 3 children in 1,000 over the age of three
have cerebral palsy. This is because of the plasticity of a child's central nervous system, or its
ability to recover completely or partially after...
(42) - 30-nov-2007
Serial Analysis of Gene Expression (SAGE), a technique that has been developed at Johns
Hopkins University in the USA, allows the analysis of overall gene expression patterns. It
is an open platform because SAGE does not require a preexisting clone, unlike microarrays.
So SAGE can be used for the identification and quantification of known genes as well as new genes. A SAGE experiment, from a statistical points of view, consists of the following 7 steps: 1. Extract a sample of mRNA fragments from a biological sample.
2. Convert the mRNA fragment into cDNA clones. 3. Generate tags by cutting 10 or 17 base long...
(63) - 05-dic-2007
Uranium is a naturally existing heavy metal found in low levels in rocks, soil and water.
In soil, the normal concentration of Uranium is 300 ?g Kg-1 to 11.7 mg Kg-1 (Wikipedia
2006). In exceptional situations, Uranium concentrations in soils can reach tens to
hundreds of milligrams per kg of soil, mostly because of mining and milling ores activities (Plant et al. 1999). High Uranium concentrations in soil can be toxic and
therefore poses danger to the living organisms.
Because of the undesirable effects of chemicals in soil, the evaluation of their toxicity becomes paramount. Toxicological tests are conducted, for instance by measuring the decrease...
(34) - 30-nov-2007