64 research outputs found
Sociological and Human Developmental Explanations of Crime: Conflict or Consensus
This paper examines multidisciplinary correlates of delinquency in an attempt to integrate sociological and environmental theories of crime with human developmental and biological explanations of crime. Structural equation models are applied to assess links among biological, psychological, and environmental variables collected prospectively from birth through age 17 on a sample of 800 black children at high risk for learning and behavioral disorders. Results show that for both males and females, aggression and disciplinary problems in school during adolescence are the strongest predictors of repeat offense behavior. Whereas school achievement and family income and stability are also significant predictors of delinquency for males, early physical development is the next strongest predictor for females. Results indicate that some effects on delinquency also vary during different ages. It is suggested that behavioral and learning disorders have both sociological and developmental correlates and that adequate educational resources are necessary to ensure channels of legitimate opportunities for high-risk youths
Recommended from our members
Early role of vascular dysregulation on late-onset Alzheimer's disease based on multifactorial data-driven analysis
Multifactorial mechanisms underlying late-onset Alzheimer's disease (LOAD) are poorly characterized from an integrative perspective. Here spatiotemporal alterations in brain amyloid-β deposition, metabolism, vascular, functional activity at rest, structural properties, cognitive integrity and peripheral proteins levels are characterized in relation to LOAD progression. We analyse over 7,700 brain images and tens of plasma and cerebrospinal fluid biomarkers from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Through a multifactorial data-driven analysis, we obtain dynamic LOAD–abnormality indices for all biomarkers, and a tentative temporal ordering of disease progression. Imaging results suggest that intra-brain vascular dysregulation is an early pathological event during disease development. Cognitive decline is noticeable from initial LOAD stages, suggesting early memory deficit associated with the primary disease factors. High abnormality levels are also observed for specific proteins associated with the vascular system's integrity. Although still subjected to the sensitivity of the algorithms and biomarkers employed, our results might contribute to the development of preventive therapeutic interventions
Natural Convection Induced By A Horizontal Laser Beam.
PhDEnergyMechanical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/180715/2/7627456.pd
Studies on nucleosomal histone acetylation and nonhistone chromosomal proteins in relation to chromatin structure
PART A - CHROMATIN SYNTHESIS
Experiments are described that suggest micrococcal nuclease selectively
excises from trout testis chromatin a population of mononucleo-somes containing increased levels of newly-synthesized histones and, possibly, newly-synthesized DNA. The results suggest that newly-synthesized
chromatin has an increased sensitivity to micrococcal nuclease digestion.
PART B - STRUCTURE OF TRANSCRIPTIONALLY ACTIVE CHROMATIN
Different nucleases were used to probe the structure of transcriptionally active chromatin. Micrococcal nuclease and deoxyribonuclease II, enzymes which preferentially digest internucleosomal linker DNA, have both been used successfully to fractionate
chromatin into transcriptionally active and inactive regions. Deoxyribonuclease I, an enzyme which digests both intra- and internucleosomal DNA, selectively destroys transcriptionally competent genes. After trout testis nuclei or chromatin was digested with one of the above nucleases, nucleosomes associated with the nuclease sensitive regions (transcriptionally active regions) were selectively eluted from the digested nuclei by the addition of low salt (0.1 M or 0.2 M NaCl); alternatively, nucleosomes were isolated from the digest products by virtue of their solubility in 0.1 M NaCl or 2 mM MgClâ‚‚. The accumulated results suggest that nucleosomes containing highly acetylated histone H4 and normal levels of the acetylated.species of histones H3, H2A and
H2B are associated with transcriptionally competent chromatin regions. Furthermore, the internucleosomal linker DNA associated with these regions contains low levels of histone Hi, and high levels of HMG-T1, HMG-T2 and HMG-T3, and lower levels of other nonhistone chromosomal proteins. The bulk of chromatin, which is transcriptionally inactive, is associated with nucleosomes containing low levels of acetylated H4 (i.e. unacetylated and monoacetylated H4 are the major species), and the internucleosomal linker DNA is associated mainly with histone H1.
The role of H4 acetylation in transcriptionally competent chromatin may be to reduce interactions between core particles and thus render the extended chromatin region accessible to RNA polymerases. Conversely, unacetylated H4 may be involved in maintaining higher levels of compaction of the chromatin.
PART C - EFFECT OF SODIUM N-BUTYRATE ON HISTONE ACETYLATION
The biochemical mechanisms underlying the increased acetylation of histones found in butyrate - treated tissue culture cells were investigated. The results clearly indicate that the increased acetylation of histone in vivo is most probably due to an inhibition of deacetylase enzyme activity caused by butyrate. This inhibition is entirely reversible and appears to be a general phenomenon, since butyrate increases levels of acetylated H3 and H4 in all tissue culture cell types (Xenopus laevis embryonic cells (X58), rat ascites cells (IRC8), mouse fibroblasts (3T3), baby hamster kidney cells (BHK) and Friend erythroleukemic cells) studied.Medicine, Faculty ofBiochemistry and Molecular Biology, Department ofGraduat
- …