Statistical Analysis of Handwriting: Probabilistic Outcomes for Closed-Set Writer Identification.

Learning Overview: The goal of this presentation is to provide insights into features of handwritten documents that are important for statistical modeling with the task of writer identification

Statistical Learning Algorithms for Forensic Scientists

Learning Overview: The goals of this workshop are to: (1) introduce attendees to the basics of supervised learning algorithms in the context of forensic applications, including firearms and footwear examination and trace evidence, while placing emphasis on classification trees, random forests, and, time permitting, neural networks; (2) introduce the concept of a similarity score to quantify the similarity between two items; (3) show how learning algorithms can be trained to classify objects into pre-determined classes; (4) discuss limitations of Machine Learning (ML) algorithms and introduce methods for assessing their performance; and (5) discuss the concept of a Score-based Likelihood Ratio (SLR): computation, advantages, and limitations

A Transformation Approach to Estimating Usual Intake Distributions

Current concerns over links between diet and health, the safety of food, and developing effective nutrition education and food assistance programs have placed increasing demands on federal data collection and methods of monitoring the food supply. Design of effective food and nutrition policies, efficient allocation of resources, and more precise targeting of programs require good estimates of the percentage of the population with deficient, or excess, nutrient or other food component intake. An individual\u27s mean daily intake of the dietary component is a good estimate of the individual\u27s dietary status. However, to evaluate dietary adequacy of a population it is necessary to obtain an estimate of the distribution of usual intakes. Often, the distribution of usual intakes is estimated from the distribution of mean daily intakes. Further, it is usually assumed that usual intakes of nutrients are normally distributed. Two problems arise. First, distributions of usual intakes for most nutrients are skewed. Second, the variance of the distribution of mean daily intakes is larger than the variance of the true usual intake distribution, due to within-individual variability of daily intakes. Some proposed adjustments produce the correct mean and variance in the estimated distribution, but fail to correct the skewness, unless the true distribution of usual intakes is normal. We describe a method for estimating usual intake distributions which does not assume normality, and which takes into account the within-individual variation in daily intake. The method consists in transforming the dietary data from the original space into normal space, and predicting the usual daily intakes in normal space. Inferences about the dietary status of the population can then be made in normal space. Alternatively, predicted normal usual intakes can be transformed back to obtain a set of pseudo usual intakes in the original scale

A TRANSFORMATION APPROACH TO ESTIMATING USUAL INTAKE DISTRIBUTIONS

Design of effective food and nutrition policies, efficient allocation of resources, and more precise targeting of food programs require good estimates of the percentage of the population with deficient, or excess, nutrient or other food component intake. An individual\u27s mean daily intake of the dietary component is a good estimate of the individual\u27s dietary status. However, to evaluate dietary adequacy of a population it is necessary to obtain an estimate of the distribution of usual intakes. Often, the distribution of usual intakes is estimated from the distribution of mean daily intakes. Two problems arise. First, distributions of usual intakes for most nutrients are skewed. Second, the variance of the distribution of mean daily intakes is larger than the variance of the true usual intake. distribution, due to within- individual variability of daily intakes. We describe a method for estimating usual intake distributions which does not assume normality, and which takes into account the within-individual variation in daily intake. The method relies on appropriate transformation of the dietary data from the original space into normal space

Gastrointestinal tract gene expression in ewes under feed restriction.

The gastrointestinal tract is known to adapt itself to changes in feed conditions and is the source of various signals that regulate feed intake and energy homeostasis. Therefore, the objective of this study was to assess the effect of a feed restriction period in the mRNA expression of target genes related to feed intake. The study was conducted in a randomized block ..

Hepatic Expression of Insulin-Like Growth Factor-1 in Underfed Pregnant Ewes

The liver is one of the most important visceral organs, which represents a large contribution to whole animal energy expenditure and the major synthetic site of insulin-like growth factor-1 (IGF-1) peptide. Decreased plane of nutrition acts by reducing the metabolic rate and mass of metabolic tissues, such as liver. Also, undernutrition results in the reduced circulating IGF-1 concentrations, due to the uncoupled growth hormone-IGF (GH-IGF) axis. This study investigated whether a 22-day period of undernutrition (half maintenance) could affect liver mass and IGF-1 protein and gene expression. Sixteen pregnant ewes fed all (n = 9) or half (n = 7) of their maintenance energy requirements were slaughtered on day 7 of pregnancy (oestrus = day 0). Body and liver mass, IGF-1 plasmatic concentrations and liver IGF-1 mRNA and protein expression were determined. Liver mass and the proportion of liver mass to empty body weight were lower in underfed animals. While IGF-1 plasmatic concentrations were lower in undernourished ewes, no differences in liver mRNA expression were found. This is the first time that differences in immunohistochemistry intensity and total content are reported in sheep. In summary, the decreased plasma IGF-1 concentrations induced by undernutrition in ewes was not associated with its reduced hepatic mRNA or protein expression, but to a decrease in liver mass