Experimental observation of a complex periodic window

The existence of a special periodic window in the two-dimensional parameter space of an experimental Chua's circuit is reported. One of the main reasons that makes such a window special is that the observation of one implies that other similar periodic windows must exist for other parameter values. However, such a window has never been experimentally observed, since its size in parameter space decreases exponentially with the period of the periodic attractor. This property imposes clear limitations for its experimental detection.Comment: 4.2 pages, 4 figure

Dynamical estimates of chaotic systems from Poincar\'e recurrences

We show that the probability distribution function that best fits the distribution of return times between two consecutive visits of a chaotic trajectory to finite size regions in phase space deviates from the exponential statistics by a small power-law term, a term that represents the deterministic manifestation of the dynamics, which can be easily experimentally detected and theoretically estimated. We also provide simpler and faster ways to calculate the positive Lyapunov exponents and the short-term correlation function by either realizing observations of higher probable returns or by calculating the eigenvalues of only one very especial unstable periodic orbit of low-period. Finally, we discuss how our approaches can be used to treat data coming from complex systems.Comment: subm. for publication. Accepted fpr publication in Chao

Nanotechnology for the treatment of deep endometriosis: uptake of lipid core nanoparticles by LDL receptors in endometriotic foci

OBJECTIVE: Rapidly dividing cells in multiple types of cancer and inflammatory diseases undergo high low density lipoprotein (LDL) uptake for membrane synthesis, and coupling an LDL-like nanoemulsion, containing lipid nanoparticles (LDE) to a chemotherapeutic agent efficiently targets these cells without significant systemic effects. This was a prospective exploratory study that evaluated the uptake of a radioactively labeled LDE emulsion by receptors of endometriotic foci and the capacity of the LDE for cellular internalization. METHODS: The lipid profile of each patient was determined before surgery, and labeled LDE were injected into fourteen patients with intestinal or nonintestinal endometriosis. The radioactivity of each tissue sample (intestinal endometriosis, nonintestinal endometriosis, healthy peritoneum, or topical endometrium) was measured. RESULTS: The group with intestinal endometriosis presented higher levels of plasma LDL but lower LDE uptake by foci than the nonintestinal group, suggesting less cell division and more fibrosis. The uptake of LDE was highest in the topical endometrium, followed by the healthy peritoneum, and lowest in the endometriotic lesion. Since the endometriotic foci showed significant LDE uptake, there was likely increased consumption of LDL by these cells, similar to cells in cancers and inflammatory diseases. Plasma cholesterol levels had no influence on LDE uptake, which showed that the direct delivery of the nanoemulsion to target tissues was independent of serum lipoproteins. There were no significant differences in the parameters (p40.01) because of the small sample size, but the findings were similar to those of previous studies. CONCLUSION: Nanotechnology is a promising therapeutic option for surgery and hormonal blockage for deep endometriosis, with a lower complication rate and no systemic side effects

The Means-End Approach to Understanding Customer Values of a On-Line Newspaper

Customer value is understood as one of the constructs that best explains consumer decision making. Its proposal is to understand how consumers translate product or service characteristics and consequences of use into personal self-relevant values. The means-end theory is a way of systematically thinking in this hierarchicalrepresentation. The most commonly used method to achieve means-end chains is laddering. This theory and method were used to understand customer values of an important on-line Brazilian newspaper, which is an innovative approach, since on-line laddering is uncommon. The findings indicate that values related to goals of a personal nature are the most important ones. However, other values indicate the increase of the public man pointing to an alternative vision of what is commonly thought of as the contemporary isolated and selfish human. Academic research could benefit from a broader understanding and use of the means-end theory and laddering on the Web. Future research for managerial practices is warranted in areas such as segmentation, satisfaction measuring and customer value reevaluation, in addition to copy tests

Reduction of atherosclerotic lesions in rabbits treated with etoposide associated with cholesterol-rich nanoemulsions

Elaine R Tavares1, Fatima R Freitas1, Jayme Diament1, Raul C Maranhão1,21Heart Institute of the Medical School Hospital (InCor), University of São Paulo, São Paulo, Brazil; 2Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, BrazilObjectives: Cholesterol-rich nanoemulsions (LDE) bind to low-density lipoprotein (LDL) receptors and after injection into the bloodstream concentrate in aortas of atherosclerotic rabbits. Association of paclitaxel with LDE markedly reduces the lesions. In previous studies, treatment of refractory cancer patients with etoposide associated with LDE had been shown devoid of toxicity. In this study, the ability of etoposide to reduce lesions and inflammatory factors in atherosclerotic rabbits was investigated.Methods: Eighteen New Zealand rabbits were fed a 1% cholesterol diet for 60 days. Starting from day 30, nine animals were treated with four weekly intravenous injections of etoposide oleate (6 mg/kg) associated with LDE, and nine control animals were treated with saline solution injections.Results: LDE-etoposide reduced the lesion areas of cholesterol-fed animals by 85% and intima width by 50% and impaired macrophage and smooth muscle cell invasion of the intima. Treatment also markedly reduced the protein expression of lipoprotein receptors (LDL receptor, LDL-related protein-1, cluster of differentiation 36, and scavenger receptor class B member 1), inflammatory cytokines (interleukin-1β and tumor necrosis factor-α), matrix metallopeptidase-9, and cell proliferation markers (topoisomerase IIα and tubulin).Conclusion: The ability of LDE-etoposide to strongly reduce the lesion area and the inflammatory process warrants the great therapeutic potential of this novel preparation to target the inflammatory-proliferative basic mechanisms of the disease.Keywords: atherosclerosis treatment, drug delivery, LDL-receptor

Insets as pollinizing agents on mango trees (Mangifera indica)

The authors study the insect population that visit the mango trees and search for their pollinizing activity. Prior operations showed that very few bees (Apis mellifera) visited the flowers of mango trees. It was known that the percentage of fecundation is low (Simão 1955), Popenoe (1929), Spencer and Kennard (1955), Lynch and Mustard (1955), Ruehle and Ledin (1955), so that the authors wented to Know if insects could be responsible for this. Insects were collected from mango trees, belonging to 10 orders, which, on the whole are not pollinizing agents. Bees were not collected, 21% were Hymenoptera, 20% were Diptera, 13% Hemiptera, 10% Coleoptera, 3% Blattariae and smoller percentages belonged to other orders

Simultaneous transfer of cholesterol, triglycerides, and phospholipids to high-density lipoprotein in aging subjects with or without coronary artery disease

OBJECTIVE: To verify whether the capacity of high-density lipoprotein (HDL) to simultaneously receive nonesterified cholesterol, triglycerides, cholesteryl esters, and phospholipids changes with aging and the presence of coronary artery disease. DESIGN: Cross-sectional study with biochemical analyses. SUBJECTS: Eleven elderly patients with coronary artery disease (74±5 years) were compared with the following groups of non-coronary artery disease subjects (referred to as "healthy"): 25 young (25±5 years), 25 middle-aged (42± years), and 25 elderly subjects (75±8 years). METHODS: Plasma samples were incubated with a nanoemulsion labeled with radioactive lipids; the transfer of the lipids from the nanoemulsion to the HDL was measured in chemically precipitated HDL. HDL size and paraoxonase-1 activity were also determined. RESULTS: The transfer of cholesteryl esters and phospholipids to high-density lipoprotein was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. Non-esterified cholesterol and triglyceride transfer was not different among these three groups. The HDL size was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. The paraoxonase-1 activity was similar among the groups. Compared with healthy elderly subjects, coronary artery disease elderly subjects had significantly less (p<0.05) transfer of non-esterified cholesterol, triglycerides, and cholesteryl esters to the HDL and a significantly smaller (p<0.05) HDL size. CONCLUSION: Because lipid transfer is enhanced in healthy elderly subjects but not in those with coronary artery disease, increasing lipid transfer to HDL may be a protective mechanism against the disease

Plasma kinetics of an LDL-like nanoemulsion and lipid transfer to HDL in subjects with glucose intolerance

OBJECTIVE: Glucose intolerance is frequently associated with an altered plasma lipid profile and increased cardiovascular disease risk. Nonetheless, lipid metabolism is scarcely studied in normolipidemic glucose-intolerant patients. The aim of this study was to investigate whether important lipid metabolic parameters, such as the kinetics of LDL free and esterified cholesterol and the transfer of lipids to HDL, are altered in glucose-intolerant patients with normal plasma lipids. METHODS: Fourteen glucose-intolerant patients and 15 control patients were studied; none of the patients had cardiovascular disease manifestations, and they were paired for age, sex, race and co-morbidities. A nanoemulsion resembling a LDL lipid composition (LDE) labeled with 14C-cholesteryl ester and ³H-free cholesterol was intravenously injected, and blood samples were collected over a 24-h period to determine the fractional clearance rate of the labels by compartmental analysis. The transfer of free and esterified cholesterol, triglycerides and phospholipids from the LDE to HDL was measured by the incubation of the LDE with plasma and radioactivity counting of the supernatant after chemical precipitation of non-HDL fractions. RESULTS: The levels of LDL, non-HDL and HDL cholesterol, triglycerides, apo A1 and apo B were equal in both groups. The 14C-esterified cholesterol fractional clearance rate was not different between glucose-intolerant and control patients, but the ³H-free-cholesterol fractional clearance rate was greater in glucose-intolerant patients than in control patients. The lipid transfer to HDL was equal in both groups. CONCLUSION: In these glucose-intolerant patients with normal plasma lipids, a faster removal of LDE free cholesterol was the only lipid metabolic alteration detected in our study. This finding suggests that the dissociation of free cholesterol from lipoprotein particles occurs in normolipidemic glucose intolerance and may participate in atherogenic signaling

Plasma kinetics of an LDL-like nanoemulsion and lipid transfer to HDL in subjects with glucose intolerance

OBJECTIVE: Glucose intolerance is frequently associated with an altered plasma lipid profile and increased cardiovascular disease risk. Nonetheless, lipid metabolism is scarcely studied in normolipidemic glucose-intolerant patients. The aim of this study was to investigate whether important lipid metabolic parameters, such as the kinetics of LDL free and esterified cholesterol and the transfer of lipids to HDL, are altered in glucose-intolerant patients with normal plasma lipids. METHODS: Fourteen glucose-intolerant patients and 15 control patients were studied; none of the patients had cardiovascular disease manifestations, and they were paired for age, sex, race and co-morbidities. A nanoemulsion resembling a LDL lipid composition (LDE) labeled with C-14-cholesteryl ester and H-3-free cholesterol was intravenously injected, and blood samples were collected over a 24-h period to determine the fractional clearance rate of the labels by compartmental analysis. The transfer of free and esterified cholesterol, triglycerides and phospholipids from the LDE to HDL was measured by the incubation of the LDE with plasma and radioactivity counting of the supernatant after chemical precipitation of non-HDL fractions. RESULTS: The levels of LDL, non-HDL and HDL cholesterol, triglycerides, apo A1 and apo B were equal in both groups. The 14 C-esterified cholesterol fractional clearance rate was not different between glucose-intolerant and control patients, but the H-3-free- cholesterol fractional clearance rate was greater in glucose-intolerant patients than in control patients. The lipid transfer to HDL was equal in both groups. CONCLUSION: In these glucose-intolerant patients with normal plasma lipids, a faster removal of LDE free cholesterol was the only lipid metabolic alteration detected in our study. This finding suggests that the dissociation of free cholesterol from lipoprotein particles occurs in normolipidemic glucose intolerance and may participate in atherogenic signaling.This study was supported by Fundação do Amparo à Pesquisa do Estado\ud de São Paulo (FAPESP), São Paulo, Brazil. Dr. Maranhão has a Research\ud Award from Conselho Nacional de Desenvolvimento Científico e\ud Tecnológico (CNPq) Brasília, Brazil. Dr. Bertato had a scholarship from\ud CNPq