Prolonged effects of a home-based intervention in patients with chronic illness

Background: Data on the long-term benefits of nonspecific disease management programs are limited. We performed a long-term follow-up of a previously published randomized trial. Methods: We compared all-cause mortality and recurrent hospitalization during median follow-up of 7.5 years in a heterogeneous cohort of patients with chronic illness initially exposed to a multidisciplinary, homebased intervention (HBI) (n = 260) or to usual postdischarge care (n = 268). Results: During follow-up, HBI had no impact on all-cause mortality (relative risk, 1.04; 95% confidence interval, 0.80-1.35) or event-free survival from death or unplanned hospitalization (relative risk, 1.03; 95% confidence interval, 0.86-1.24). Initial analysis suggested that HBI had only a marginal impact in reducing unplanned hospitalization, with 677 readmissions vs 824 for the usual care group (mean +/- SD rate, 0.72 +/- 0.96 vs 0.84 +/- 1.20 readmissions/patient per year; P = .08). When accounting for increased hospital activity in HBI patients with chronic obstructive pulmonary disease during follow-up for 2 years, post hoc analyses showed that HBI reduced readmissions by 14% within 2 years in patients without this condition (mean +/- SD rate, 0.54 +/- 0.72 vs 0.63 +/- 0.88 readmission/patient per year; P =. 04) and by 21% in all surviving patients within 3 to 8 years (mean +/- SD rate, 0.64 +/- 1.26 vs 0.81 +/- 1.61 readmissions/ patient per year; P =. 03). Overall, recurrent hospital costs were significantly lower ( 14%) in the HBI group (mean +/- SD, $ 823 +/- $ 1642 vs $ 960 +/- $ 1376 per patient per year; P =. 045). Conclusion: This unique study suggests that a nonspecific HBI provides long-term cost benefits in a range of chronic illnesses, except for chronic obstructive pulmonary disease.

On the microstructure, growth pattern and original porosity of belemnite rostra: insights from calcitic Jurassic belemnites

Calcitic belemnite rostra are usually employed to perform paleoenvironmental studies based on geochemical data. However, several questions, such as their original porosity and microstructure, remain open, despite they are essential to make accurate interpretations based on geochemical analyses.This paper revisits and enlightens some of these questions. Petrographic data demonstrate that calcite crystals of the rostrum solidum of belemnites grow from spherulites that successively develop along the apical line, resulting in a “regular spherulithic prismatic” microstructure. Radially arranged calcite crystals emerge and diverge from the spherulites: towards the apex, crystals grow until a new spherulite is formed; towards the external walls of the rostrum, the crystals become progressively bigger and prismatic. Adjacent crystals slightly vary in their c-axis orientation, resulting in undulose extinction. Concentric growth layering develops at different scales and is superimposed and traversed by a radial pattern, which results in the micro-fibrous texture that is observed in the calcite crystals in the rostra.Petrographic data demonstrate that single calcite crystals in the rostra have a composite nature, which strongly suggests that the belemnite rostra were originally porous. Single crystals consistently comprise two distinct zones or sectors in optical continuity: 1) the inner zone is fluorescent, has relatively low optical relief under transmitted light (TL) microscopy, a dark-grey color under backscatter electron microscopy (BSEM), a commonly triangular shape, a “patchy” appearance and relatively high Mg and Na contents; 2) the outer sector is non-fluorescent, has relatively high optical relief under TL, a light-grey color under BSEM and low Mg and Na contents. The inner and fluorescent sectors are interpreted to have formed first as a product of biologically controlled mineralization during belemnite skeletal growth and the non-fluorescent outer sectors as overgrowths of the former, filling the intra- and inter-crystalline porosity. This question has important implications for making paleoenvironmental and/or paleoclimatic interpretations based on geochemical analyses of belemnite rostra.Finally, the petrographic features of composite calcite crystals in the rostra also suggest the non-classical crystallization of belemnite rostra, as previously suggested by other authors.

Making Functionality More General

The definition for the notion of a "function" is not cast in stone, but depends upon what we adopt as types in our language. With partial equivalence relations (pers) as types in a relational language, we show that the functional relations are precisely those satisfying the simple equation f = f o fu o f, where "o" and "u" are respectively the composition and converse operators for relations. This article forms part of "A calculational theory of pers as types".