50 research outputs found
Uniform asymptotics of the coefficients of unitary moment polynomials
Keating and Snaith showed that the absolute moment of the
characteristic polynomial of a random unitary matrix evaluated on the unit
circle is given by a polynomial of degree . In this article, uniform
asymptotics for the coefficients of that polynomial are derived, and a maximal
coefficient is located. Some of the asymptotics are given in explicit form.
Numerical data to support these calculations are presented. Some apparent
connections between random matrix theory and the Riemann zeta function are
discussed.Comment: 31 pages, 1 figure, 2 tables. A few minor misprints fixe
Asymmetric Hsp90 N domain SUMOylation recruits Aha1 and ATP-competitive inhibitors
The stability and activity of numerous signaling proteins in both normal and cancer cells depends on the dimeric molecular chaperone heat shock protein 90 (Hsp90). Hsp90's function is coupled to ATP binding and hydrolysis and requires a series of conformational changes that are regulated by cochaperones and numerous posttranslational modifications (PTMs). SUMOylation is one of the least-understood Hsp90 PTMs. Here, we show that asymmetric SUMOylation of a conserved lysine residue in the N domain of both yeast (K178) and human (K191) Hsp90 facilitates both recruitment of the adenosine triphosphatase (ATPase)-activating cochaperone Aha1 and, unexpectedly, the binding of Hsp90 inhibitors, suggesting that these drugs associate preferentially with Hsp90 proteins that are actively engaged in the chaperone cycle. Importantly, cellular transformation is accompanied by elevated steady-state N domain SUMOylation, and increased Hsp90 SUMOylation sensitizes yeast and mammalian cells to Hsp90 inhibitors, providing a mechanism to explain the sensitivity of cancer cells to these drugs. © 2014 Elsevier Inc
Hospitalizations during the last months of life of nursing home residents: a retrospective cohort study from Germany
BACKGROUND: To describe hospitalisations of nursing home (NH) residents in Germany during their last months of life. METHODS: Retrospective cohort study on 792 NH residents in the Rhine-Neckar region in South-West Germany, newly institutionalized in the year 2000, who died until the study end (December 2001). Baseline variables were derived from a standardized medical examination routinely conducted by the medical service of the health care insurance plans in Germany. Information on hospitalisations and deaths was extracted form records of the pertinent health insurance plans. RESULTS: NH residents who died after NH stay of more than 1 year spent 5.8% of their last year of life in hospitals. Relative time spent in hospitals increased from 5.2% twelve months before death (N = 139 persons) to 24.1% in their last week of life (N = 769 persons). No major differences could be observed concerning age, gender or duration of stay in NH. Overall, 229 persons (28.9%) died in hospital. Among these, the last hospital stay lasted less than 3 days for 76 persons (31.9%). Another 25 persons (3.2%) died within three days after hospital discharge. CONCLUSION: Our study indicates that proximity of death is the most important driver of health care utilization among NH residents. The relation of age or gender to health care expenditures seem to be weak once time to death is controlled for. Duration of NH stay does not markedly change rates of hospitalisation during the last months of life
Asymptotic Estimates for Generalized Stirling Numbers
Uniform asymptotic expansions are given for the Stirling numbers of the first kind for integral arguments and for the second kind as defined for real arguments by Flajolet and Prodinger. The logconcavity of the resulting real valued function of Flajolet and Prodinger is established for a range including the classical integral domain
In 1995 a correlation between malnutrition and poor outcome in critically ill patients still exists.
After more than two decades of nutritional awareness, we designed a prospective study to determine whether malnutrition is still a significant issue in hospitalized patients. Patients admitted to an intensive care unit (ICU) were divided into well-nourished and malnourished groups, according to their nutritional status as assessed by serum albumin level and weight/height ratio. Severity of illness, as assessed by the Therapeutic Intervention Scoring System (TISS), was used to further stratify the study population. All patients were followed clinically until discharge or death and their outcome recorded. Of 129 patients studied, 43% were malnourished. Length of hospital stay (p = n.s.), incidence of complications (p < 0.01), and number of patients not discharged from hospital (p < 0.05) were greater in the malnourished patients than in the well-nourished. In patients with less severe degrees of illness, the existence of malnutrition led to a worse outcome than in sicker patients. To further assess the clinical setting in which hospital-related malnutrition develops or is exacerbated, postoperative patients admitted to the ICU (n = 66) were also studied in a nutritional survey; the results of this survey indicate that: (a) the incidence of malnutrition in the surgical population is similar to that in the whole study population, and (b) hospital-related malnutrition in surgical patients mainly develops during their preoperative stay in general wards. Whereas our conclusion that patients' outcome is adversely affected by a poor nutritional status is not new or startling, malnutrition continues to be a persistent problem in hospitalized patients, which can be readily identified using simple and easily available indices and, furthermore, readily treated