On the stability of linear repetitive processes described by a delay-difference equation

This paper considers linear repetitive processes which are a distinct class of two-dimensional linear systems of both physical and systems theoretic interest. Their essential unique feature is a series of sweeps, termed passes, through a set of dynamics defined over a finite and fixed duration known as the pass length. The result can be oscillations in the output sequence of pass profiles which increase in amplitude in the pass-to-pass direction. This cannot be controlled by existing techniques and instead control must be based on a suitably defined stability theory. In the literature to date, the development of such a theory has been attempted from two different starting points, and in this paper, we critically compare these for dynamics defined by a delay-difference equation.     

Stress-induced hemoconcentration of blood cells and lipids in healthy women during acute psychological stress.

This study examined the effects of psychological stress on hemoconcentration in women. Hematologic and hemodynamic variables were assessed in 17 women before and after a 3-min speech task. Significant changes in hematocrit, hemoglobin levels, red and white blood cell (WBC) count, and calculated plasma volume occurred during psychological stress (all ps?ps?p?p?     

Aging and the dendritic morphology of the rat laterodorsal and pedunculopontine tegmental nuclei

This study is based on interviews with 37 persons fulfilling the DSM-IV criteria for kleptomania recruited through newspaper advertisements, and on 50 shoplifters interviewed directly after apprehension. Our hypothesis was that there are no absolute borders between 'pure' kleptomania according to DSM-IV and other forms of shoplifting. When asked about the latest case of shoplifting, one fifth of the shoplifters reported not having stolen the item for personal use and had later discarded it. A quarter of the kleptomaniacs reported ambivalence when asked if they needed the item in question. The degree of reported impulsivity and a feeling of not being oneself at the time of the theft was the same in the two groups. The two groups also estimated their degree of impulsivity, planning, thrill, relief, vengeance, need, pleasure on a Visual Analogue Scale (VAS) as well as the degree of psychiatric imbalance on the latest theft occasion. These estimates showed that there were no differences between the groups concerning the degree of planning, psychological imbalance and the need for the stolen item in question. The kleptomaniacs rated a feeling of inner tension before the theft higher than the shoplifters. The same was true concerning a feeling of relief during the theft and impulsivity. However, the shoplifters also rated high on all these items. Altogether, these findings support our hypothesis that many shoplifters, even if they do not fulfill all DSM criteria for kleptomania, may constitute a significant medical problem and should be offered support and treatment. Anti-depressants as well as the educational programmes developed by the Shoplifters Alternatives may be effective not only in cases of kleptomania but also for more unselected groups of non-professional shoplifters.     

Systematic screening of the LDL-PLA2 gene for polymorphic variants and case-control analysis in schizophrenia

Systematic scans of the genome using microsatellite markers have identified chromosome 6p21.1 as a putative locus for schizophrenia in multiply affected families. There is also evidence from a series of studies for a role of abnormal phospholipid metabolism in schizophrenia. In light of these findings, and the role of platelet activating factor in neurotransmission and neurodevelopment, we have examined the LDL-PLA2 (plasma PAF acetylhydrolase, PAF-AH) gene, a serine dependent phospholipase that has been mapped by hybrid mapping to chromosome 6p21.1, as a positional candidate gene for schizophrenia. The gene was systematically screened using SSCP/HD analysis for polymorphisms associated with the disease. Four polymorphic variants were found within the gene and studied in a group of 200 schizophrenic patients and 100 controls. The variant in exon 7 (Iso195Thr) was found to be weakly associated with schizophrenia (p = 0.04) and the variant in exon 11 (Val379Ala) almost reached significance (p = 0.057). After correcting for multiple testing no significant associations were detected. Haplotype analysis combining pairs of polymorphisms also provided no evidence for association of this gene with schizophrenia in our sample of patients.     

Hospital admissions of HIV-infected patients from 1988 to 1992 in Maryland

To determine how the patterns of inpatient hospital care for HIV-infected patients have evolved in recent years, we analyzed data obtained from a statewide hospital discharge database from Maryland for the years 1988, 1990, and 1992. For each of these years, we compared demography, diagnoses, lengths of stay, use of the intensive care unit, third-party payer, and hospital charges (inflation-adjusted to 1992 dollars). HIV-infected patients accounted for 0.42% of all Maryland's hospital admissions in 1988, 0.68% in 1990, and 1.1% in 1992, with progressively more women and African-Americans hospitalized. Average lengths of stay fell from 11.7 days (1988) to 10.7 days (1990) and 9.5 days (1992) (p < 0.0001). Average charges per admission fell from $11,634 (1988) to $9,938 (1990) and $8,618 (1992) (p < 0.0001). Medicare or Medicaid paid for 50.9% of hospital admissions in 1988, 56.8% in 1990, and 66.8% in 1992 (p < 0.001). In-hospital mortality rates (7.8% in 1988, 7.9% in 1990, and 7.7% in 1992; p = 0.783) were stable, as was severity of illness. P. carinii pneumonia (PCP) was the most common principal diagnosis, but it declined in prevalence from 13.6% in 1988 to 9.1% in 1992 (p < 0.0001). Principal diagnoses of other opportunistic infections remained stable (8.0% in 1988, 9.9% in 1990, 8.6% in 1992; p = 0.90), as did other nonopportunistic infections (32.8% in 1988, 27.2% in 1990, and 30.0% in 1992; p = 0.16). Non-PCP pneumonias increased from 7.6% (1988) to 10.2% (1992) (p < 0.0001). Substance abuse as a principal or secondary diagnosis increased from 30.9% (1988) to 34.3% (1992) (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

H/sub /spl infin// control of differential linear repetitive processes

Repetitive processes are a distinct class of two-dimensional (2-D) systems (i.e., information propagation in two independent directions) of both systems theoretic and applications interest. They cannot be controlled by direct extension of existing techniques from either standard [termed one-dimensional (1-D) here] or 2-D systems theory. Here, we give new results on the relatively open problem of the design of control laws using an H/sub /spl infin// setting. These results are for the sub-class of so-called differential linear repetitive processes which arise in applications.     

A prospective study of endogenous serum hormone concentrations and breast cancer risk in post-menopausal women on the island of Guernsey

The associations between serum concentrations of oestradiol, testosterone and sex hormone-binding globulin (SHBG) and risk of breast cancer in post-menopausal women were investigated in a prospective study on the island of Guernsey. Sixty-one women who developed breast cancer an average of 7.8 years after blood collection were matched for age, year of blood collection and number of years post-menopausal with 179 control subjects. Women using exogenous hormones at the time of blood collection were excluded from the study. Women who subsequently developed breast cancer had a 29% higher geometric mean oestradiol concentration than control women (P = 0.004). The odds ratio for breast cancer in the top third compared with the lowest third of the oestradiol concentration distribution was 5.03 (95% confidence interval 2.02-12.49, P for trend < 0.001). Adjusting for testosterone and SHBG concentrations did not substantially alter the odds ratio for oestradiol. Although testosterone and SHBG concentrations were associated with breast cancer risk, the concentrations of these hormones were correlated with those of oestradiol; the associations were not statistically significant after adjusting for oestradiol concentration. These data provide evidence that serum oestradiol concentrations in post-menopausal women may have a substantial effect on breast cancer risk.