Final nanoparticle size distribution under unusual parameter regimes.

We explore the large-scale behavior of a stochastic model for nanoparticle growth in an unusual parameter regime. This model encompasses two types of reactions: nucleation, where n monomers aggregate to form a nanoparticle, and growth, where a nanoparticle increases its size by consuming a monomer. Reverse reactions are disregarded.

An Application of Maximal Exponential Models to Duality Theory.

We use maximal exponential models to characterize a suitable polar cone in a mathematical convex optimization framework. A financial application of this result is provided, leading to a duality minimax theorem related to portfolio exponential utility maximization.

Time to first relapse as an endpoint in multiple sclerosis clinical trials.

Background: The increasing number of effective therapies to treat multiple sclerosis (MS) raises ethical concerns for the use of placebo in clinical trials, suggesting that new clinical trial design strategies are needed.

Objectives: To evaluate time to first relapse as an endpoint for MS clinical trials.

Methods: A recently-developed model fitting the distribution of time to first relapse in MS was used for simulations estimating the sample sizes of trials using this as an outcome, and for comparison with the size of trials using the annualized relapse rate (ARR) as the primary outcome.

A parametric model fitting time to first event for overdispersed data: application to time to relapse in multiple sclerosis.

In this article, we propose a parametric model for the distribution of time to first event when events are overdispersed and can be properly fitted by a Negative Binomial distribution. This is a very common situation in medical statistics, when the occurrence of events is summarized as a count for each patient and the simple Poisson model is not adequate to account for overdispersion of data. In this situation, studying the time of occurrence of the first event can be of interest.

Aberrant hepatic expression of PPARgamma2 stimulates hepatic lipogenesis in a mouse model of obesity, insulin resistance, dyslipidemia, and hepatic steatosis.

Insulin-resistant apoB/BATless mice have hypertriglyceridemia because of increased assembly and secretion of very low density apolipoprotein B (apoB) and triglycerides compared with mice expressing only apoB (Siri, P., Candela, N., Ko, C.

Proliferation and death in a binary environment: a stochastic model of cellular ecosystems.

The activation, growth and death of animal cells are accompanied by changes in the chemical composition of the surrounding environment. Cells and their microscopic environment constitute therefore a cellular ecosystem whose time-evolution determines processes of interest for either biology (e.g.

Influence of dietary carbohydrate and fat on LDL and HDL particle distributions.

Variations in the size and density distributions of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles have been related to risk for cardiovascular disease. In particular, increased levels of small, dense LDL particles, together with reduced levels of large HDL and increases in small HDL, are integral features of the atherogenic dyslipidemia found in patients with insulin resistance, obesity, and metabolic syndrome. Increased dietary carbohydrates, particularly simple sugars and starches with high glycemic index, can increase levels of small, dense LDL and HDL, primarily by mechanisms that involve increasing plasma triglyceride concentrations.

Dyslipidemia in type 2 diabetes.

Type 2 diabetes mellitus is associated with a cluster of lipid abnormalities:elevated plasma triglycerides, reduced high-density lipoprotein cholesterol, and smaller and denser low-density lipoproteins,which have been associated with an increased risk of cardiovascular disease. Insulin resistance may contribute to dyslipidemia associated with type 2 diabetes by increasing hepatic secretion of large,triglyceride-rich very low-density lipoprotein particles and by impairing the clearance of lipoprotein particles from plasma. Lifestyle interventions may be effective in improving the diabetic dyslipidemia syndrome.

Metabolic abnormalities: triglyceride and low-density lipoprotein.

Increased plasma triglyceride and reduced high-density lipoprotein cholesterol are key features of the metabolic syndrome. Although elevated low-density lipoprotein cholesterol is not an integral characteristic of this syndrome, there is commonly an increase in the proportion of small, dense low-density lipoprotein particles. Together, these abnormalities constitute the atherogenic dyslipidemia of the metabolic syndrome.

Ovariectomy leads to increased insulin resistance in human apolipoprotein B transgenic mice lacking brown adipose tissue.

We studied the role of estrogen in the gender differences in insulin resistance observed in the apoB/BATless mouse, a model of obesity, insulin resistance, and hyperlipidemia. Ovariectomized apoB/BATless mice were more obese and more insulin-resistant than sham ovariectomized apoB/BATless mice. Estrogen replacement by subcutaneous pellet reversed the obesity, lowered plasma insulin levels, and normalized both glucose tolerance and insulin sensitivity associated with ovariectomy.

Post-transcriptional stimulation of the assembly and secretion of triglyceride-rich apolipoprotein B lipoproteins in a mouse with selective deficiency of brown adipose tissue, obesity, and insulin resistance.

A mouse model of insulin resistance and its associated dyslipidemia was generated by crossing mice expressing human apolipoprotein B (apoB) with mice lacking only brown adipose tissue (BATless). On a high fat diet, male apoB/BATless mice became obese, hypercholesterolemic, hypertriglyceridemic, and hyperinsulinemic compared with control apoB mice. Fast performance liquid chromatography revealed increased triglyceride concentrations in intermediate density lipoprotein/low density lipoprotein (LDL) and reduced high density lipoprotein cholesterol concentrations.

'First steps': using rapid assessment and response methods to develop research, intervention and advocacy capacity for addressing drug use in Rosario City, Argentina.

During the last decade, injecting drug use (IDU) has increased in Rosario City, Argentina, and more than half of all reported HIV cases are thought to be related to the sharing of injection equipment. Despite this, valid and systematic data on the extent and nature of injecting drug use are rare, and only a limited number of HIV prevention interventions currently operate in the city. In response, the Universidad Nacional de Rosario have used the Spanish translation of the Rapid Assessment and Response Guide on Injecting Drug Use (IDU-RAR) developed by the World Health Organization (WHO.

Vitamins B6, B12, and folate: association with plasma total homocysteine and risk of coronary atherosclerosis.

Objectives: To investigate the association of status of vitamins B6, B12 and folate with plasma fasting total homocysteine (tHcy) and with risk of coronary atherosclerosis; and to establish whether associations between vitamins and risk of coronary atherosclerosis are mediated by tHcy.

Methods: The study population consisted of 131 patients with angiography-defined severe coronary atherosclerosis and 88 referents with no or minor coronary stenosis. Previous analyses in this study population have shown that fasting tHcy is an independent risk factor for coronary atherosclerosis.

Carbachol-induced bladder mast cell activation: augmentation by estradiol and implications for interstitial cystitis.

Objectives: Interstitial cystitis (IC) is a painful, sterile bladder disorder that occurs primarily in women, many of whom also experience allergies with symptoms that worsen perimenstrually. Increased numbers of activated bladder mast cells have recently been implicated in the pathophysiology of IC. These mast cells express high-affinity estrogen receptors and are located close to increased bladder nerves, many of which contain the neuropeptide substance P (SP).

Consorting among juvenile Midas cichlids (Cichlasoma citrinellum) in relation to own and to parents' color.

Adults of the Midas cichlid, Cichlasoma citrinellum, are either normal (N) colored or gold (G); they mate assortatively by color, and that choice is influenced by prior experience with their parents. Three groups of N and two groups of G juveniles were reared by parents which were either N or G. After some months of separation from their parents, the juveniles were tested to ascertain whether the color of their parents or of their cohorts affected their affiliative responses; they were given a choice between four G and four N juveniles.