Hydrodynamic Interactions, Hidden Order, and Emergent Collective Behavior in an Active Bacterial Suspension

Spontaneous self-organization (clustering) in magnetically oriented bacteria arises from attractive pairwise hydrodynamics, which are directly determined through experiment and corroborated by a simple analytical model. Lossless compression algorithms are used to identify the onset of many-body self-organization as a function of experimental tuning parameters. Cluster growth is governed by the interplay between hydrodynamic attraction and magnetic dipole repulsion, leading to logarithmic time dependence of the cluster size. The dynamics of these complex, far-from-equilibrium structures are relevant to broader phenomena in condensed matter, statistical mechanics, and biology.

Impact of diabetes on inpatient mortality and length of stay for elderly patients presenting with fracture of the proximal femur

INTRODUCTION

Osteoporosis-related fractures of the proximal femur cause significant morbidity and result in an economic burden on societies. It remains debatable whether diabetic patients with proximal fracture of the femur demonstrate poorer outcomes in terms of hospital stay and mortality compared to non-diabetic controls.

METHODS

All patients over 65years old admitted to the University Hospital Birmingham during 2007-2010 with a diagnosis of a fracture of the proximal femur (total 1468 including 197 patients with diabetes) were analysed. Eligibility and case definitions were ascertained using electronic records. Multivariate analyses were conducted to control for the confounding effect of covariates, which may be associated with the outcomes of interest on the basis of biological plausibility and known risks.

RESULTS

In-patient mortality was estimated at 14.2% and 12% for the diabetic and non-diabetic patients respectively. Diabetes was not found to be a significant predictor of in-patient mortality, before and after adjustment for the covariates [Adjusted odds ratio 1.01 (95% CI 0.62-1.65)], in contrast to advancing age, male gender, co-morbidity score, low albumin and high creatinine concentrations. Similarly, median length of stay was greater in the diabetes patients, yet only by a day (20 versus 19 days). This was not statistically significant in either the unadjusted (p=0.17) or in the multivariate analysis (p=0.06).

CONCLUSIONS

Diabetic patients admitted with fracture of the proximal femur did not demonstrate significantly poorer outcomes in terms of in-patient mortality and length of stay compared to non-diabetic patients.