Substructure Discovery Using Minimum Description Length and Background Knowledge

The ability to identify interesting and repetitive substructures is an essential component to discovering knowledge in structural data. We describe a new version of our SUBDUE substructure discovery system based on the minimum description length principle. The SUBDUE system discovers substructures that compress the original data and represent structural concepts in the data. By replacing previously-discovered substructures in the data, multiple passes of SUBDUE produce a hierarchical description of the structural regularities in the data. SUBDUE uses a computationally-bounded inexact graph match that identifies similar, but not identical, instances of a substructure and finds an approximate measure of closeness of two substructures when under computational constraints. In addition to the minimum description length principle, other background knowledge can be used by SUBDUE to guide the search towards more appropriate substructures. Experiments in a variety of domains demonstrate SUBDUE's ability to find substructures capable of compressing the original data and to discover structural concepts important to the domain. Description of Online Appendix: This is a compressed tar file containing the SUBDUE discovery system, written in C. The program accepts as input databases represented in graph form, and will output discovered substructures with their corresponding value.Comment: See http://www.jair.org/ for an online appendix and other files accompanying this articl

The Health and Health Care of People with Intellectual Disabilities

New research studies conducted by Special Olympics found disturbing evidence that individuals with intellectual disabilities face widespread health problems, while physicians, dentists and other health professionals are not receiving adequate training in order to treat them. The research reinforces previous studies that found that despite the widespread belief that individuals with intellectual disabilities receive better health care than the rest of the population, people with intellectual disabilities actually have poorer health, more specialized ealth care needs and greater difficulty accessing health care services and doctors compared to the general public.Research Methodology: Special Olympics recently commissioned two research studies related to the health and health care of individuals with intellectual disabilities

THE EFFECTS OF SLOW RELEASE UREA ON NITROGEN METABOLISM IN CATTLE

The objective of this research was to investigate the effects of slow release urea on N metabolism in cattle. The ruminal behavior of Optigen®II and the effect of basal diet on the in situ degradability of urea and Optigen®II were evaluated. The effect of slow release urea and its interaction with degradable intake protein (DIP) level in the diet on N retention and excretion was evaluated utilizing 8 Holstein steers in a 4 x 4 Latin square experiment. In addition, the effect of slow release urea and DIP level on ruminal and systemic urea kinetics was evaluated using stable isotope techniques with 8 Holstein steers in a 4 x 4 Latin square experiment. Finally, slow release urea was evaluated under a practical beef production setting. The performance of slow release urea was compared to regular feed grade urea in a 42 day receiving study (288 Angus cross steers) as well as a 70 day growing study (240 Angus cross steers). High forage diets increased the ruminal degradation rate of both urea and slow release urea an increased the extent of degradation of slow release urea when compared to high concentrate diets. Lower DIP concentrations in the diet reduced systemic urea production, ruminal ammonia and plasma urea concentrations and urinary urea excretion under most circumstances but also led to a reduction in N retention, reduced diet digestibility, lower feed intake, lower growth rate and decreased feed efficiency. High DIP intakes increased N retention, growth rate, diet digestibility and improved feed efficiency but also lead to increased excretion on urea N in the urine. Slow release urea improved N retention and efficiency of N retention in high DIP diets when compared to urea and generally reduced plasma urea and ruminal ammonia concentrations. Compared to urea, slow release urea did not significantly improve the production of receiving cattle. However Optigen®II improved the feed efficiency when compared to urea on high concentrate diets but reduced feed efficiency on high forage diets

A retrospective study of the prevalence of the canine degenerative myelopathy associated superoxide dismutase 1 mutation (SOD1: c. 118G> A) in a referral population of German Shepherd dogs from the UK

BACKGROUND: Canine degenerative myelopathy (CDM) is an adult onset, progressive neurodegenerative disease of the spinal cord. The disease was originally described in the German Shepherd dog (GSD), but it is now known to occur in many other dog breeds. A previous study has identified a mutation in the superoxide dismutase 1 gene (SOD1:c.118G > A) that is associated with susceptibility to CDM. In the present study, restriction fragment length polymorphism (RFLP) analysis was used to genotype GSD for SOD1:c.118G > A in order to estimate the prevalence of the mutation in a referral population of GSD in the UK. RESULTS: This study demonstrated that the RFLP assay, based on use of PCR and subsequent digestion with the Eco571 enzyme, provided a simple genotyping test for the SOD1:c.118G > A mutation. In a young GSD population (i.e. dogs less than 6 years of age, before clinical signs of the disease usually become apparent), 8 of 50 dogs were found to be homozygous and a further 19 were heterozygous for the mutation. In dogs over 8 years of age, 21 of 50 dogs admitted to a tertiary referral hospital with pelvic limb ataxia as a major clinical sign were homozygous for the mutation, compared to none of 50 dogs of similar age, but where no neurological disease was reported on referral. CONCLUSIONS: This data suggests that genotyping for the SOD1:c.118G > A mutation is clinically applicable and that the mutation has a high degree of penetrance. Genotyping might also be useful for screening the GSD population to avoid mating of two carriers, but since the allele frequency is relatively high in the UK population of GSD, care should be taken to avoid reduction in genetic diversity within the breed