Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: Physical activity has been associated with reduced risk of coronary heart disease. A mechanism for the reduced risk may be through increased high density lipoprotein cholesterol (HDL-C) and subfractions, in particular HDL2-C. Research associated with increased physical activity investigating HLD-C have assessed the effects of intense aerobic activity. The current research evaluated the relationship between low intensity, long duration activity to HDL-C and subfractions in 35 active postal carriers. Measurements of physical activity via the Large Scale Integrated monitor and reported miles walked, and lipoproteins were assessed at 3-month intervals over a 1-year period. Reported miles walked/day (5.3) was significantly correlated with HLD2-C (r = 0.50, P = 0.003) and approached significance for HDL-C (r = 0.29, P = 0.06). The Large Scale Integrated measures were correlated with HDL-C (r = 0.44, P = 0.008) and HDL2-C (r = 0.44, P = 0.007). Controlling for either age, alcohol consumption, body mass index, or leisure time activity did not reduce the relationship between reported miles walked or Large Scale Integrated readings and HDL2-C, suggesting that the increased HDL-C was the result of long duration, low intensity physical activity.
Chronic low level physical activity as a determinant of high density lipoprotein cholesterol and subfractions.

Abstract: The crossing over in five murine I-region recombinants (Is/Ik) was studied by restriction fragment length polymorphism analysis after Southern blot hybridization by using I-region-specific probes. These recombinants included three recently developed strains, B10.ASR1, B10.ASR11, and B10.ASR12; and two strains B10.S(9R) and B10.HTT derived earlier. Although these recombinants were reciprocal in haplotype orientation to the three recombinants we reported recently, these too crossed over within the same 7 kb stretch of DNA in the E beta gene. This 7 kb stretch of DNA included the 3' half of the first intron, the beta 1 exon, the second intron, and the beta 2 exon. A comparison of the cDNA sequences of the two parental E beta alleles revealed that although the beta 2 exons were identical, there were several nucleotide differences between the two beta 1 exons. This allowed us to determine the parental origin of the beta 1 exon in the recombinants at the level of transcription by using S1 nuclease mapping. Thus we were able to show that in each case the 3' portion of the first intron and the beta 1 exon were upstream from the site of crossover. All eight recombinants involving the k and s haplotypes now can be mapped within a 4.5 kb stretch of DNA, which includes only the beta 1-beta 2 intron and the beta 2 exon of the E beta gene. These findings imply that the I-E molecules expressed in these recombinants will probably have conserved sequences and therefore will exhibit identical I-E-restricted immune responses, despite the fact that crossing over could have occurred at different sites within the beta 1-beta 2 intron.
Molecular mapping of murine I region recombinants. II. Crossing over in the E beta gene is restricted to a 4.5 kb stretch of DNA that excludes the beta 1 exon.

Abstract: A review of 77 patients with traumatic central cord syndrome revealed that atypical variations are more common than the existing literature suggests and that these may be seen in a wide variety of acute injuries to the cervical spine. In general the outcome is good; a favourable prognosis on admission is suggested by good hand function, hyperpathia, Lhermitte's sign and normal perianal sensation. The study has highlighted the value of regular muscle charting and has cast doubt on previous neuroanatomical assumptions about the syndrome.

A reappraisal of acute traumatic central cord syndrome.

