Perfect Information vs Random Investigation: Safety Guidelines for a Consumer in the Jungle of Product Differentiation

We present a graph-theoretic model of consumer choice, where final decisions are shown to be influenced by information and knowledge, in the form of individual awareness, discriminating ability, and perception of market structure. Building upon the distance-based Hotelling's differentiation idea, we describe the behavioral experience of several prototypes of consumers, who walk a hypothetical cognitive path in an attempt to maximize their satisfaction. Our simulations show that even consumers endowed with a small amount of information and knowledge may reach a very high level of utility. On the other hand, complete ignorance negatively affects the whole consumption process. In addition, rather unexpectedly, a random walk on the graph reveals to be a winning strategy, below a minimal threshold of information and knowledge.Comment: 27 pages, 12 figure

Tipos nomenclaturais e principais famílias do Herbário CNPO da Embrapa Pecuária Sul.

Conceitos Nomenclaturais; Tipos de Tipos Nomenclaturais; Holótipo; Lectótipo; Neótipo; Isótipo; Síntipo; Parátipo; Topótipobitstream/item/56603/1/DT116.pd

Effect of intraoperative fluid optimisation on renal function in patients undergoing emergency abdominal surgery; a randomised controlled pilot study (ISRCTN 11799696) Fluid optimisation for emergency surgery

<b>Background:</b> Emergency abdominal surgery carries a high risk of postoperative morbidity and mortality. Goal directed therapy has been advocated to improve outcome in high-risk surgery. The aim of the present pilot study was to examine the effect of goal directed therapy using fluid alone on postoperative renal function and organ failure score in patients undergoing emergency abdominal surgery. <b>Methods:</b> This prospective randomised pilot study included patients over the age of 50 undergoing emergency abdominal surgery. In the intervention group pulse pressure variation measurements were used to guide fluid boluses of 6% Hydroxyethylstarch 130/0.4. The control group received standard care. Serum urea, creatinine and cystatin C levels were measured prior to and at the end of surgery and postoperatively on day 1, day 3 and day 5. <b>Results:</b> Thirty patients were recruited. One patient died prior to surgery and was excluded from the analysis. The intervention group received a median of 750ml of hydroxyethylstarch. The peak values of postoperative urea were 6.9 (2.7–31.8) vs. 6.4 (3.5–11.5)mmol/l (p=0.425), creatinine 100 (60–300) vs. 85 (65–150) μmol/l (p=0.085) and cystatin C 1.09 (0.66–4.94) vs. 1.01 (0.33–2.29)mg/dl (p=0.352) in the control and intervention group, respectively. <b>Conclusions:</b> In the present pilot study replacing the identified fluid deficit was not associated with a change in renal function. These results do not preclude that goal directed therapy using fluid alone may have an effect on renal function but they would suggest that the effect size of fluid optimisation alone on renal function is small