Using data from a geopolitical forecasting tournament, Mellers et al. (2014) [Psychological strategies for winning a geopolitical forecasting tournament. , 1106-1115] concluded that forecasting ability was improved by allowing participants to work in teams and providing them with probability training.
View Article and Find Full Text PDFDespite the common assumption that citations are indicative of an article's scientific merit, increasing evidence indicates that citation counts are largely driven by variables unrelated to quality. In this article, we treat people's decisions of what to cite as an instance of memory retrieval and show that observed citation patterns are well accounted for by a model of memory. The proposed exposure model anticipates that small alterations in factors that affect people's ability to retrieve to-be-cited articles from memory early in their life cycle are magnified over time and can lead to the emergence of highly cited papers.
View Article and Find Full Text PDFTheories of how people value and search for information share the assumption that beliefs give rise to the perceived value of information. However, few studies have directly addressed the pre-search processes that influence information-foraging behavior. This experiment examined the influence of pre-search belief updating on the perceived value of information sources.
View Article and Find Full Text PDFObjective: The reported study evaluated a novel approach to aiding geospatial reasoning and decision making.
Background: Impact mapping aims to alleviate the cognitive demands of geospatial tasks in part by externalizing data in the form of an integrated decision surface. This is achieved by aggregating data across multiple sources of information and visualizing their combined utility rather than objective measurements or individual utility.
Although temporal dynamics are inherent aspects of diagnostic tasks, few studies have investigated how various aspects of time course influence hypothesis generation. An experiment is reported that demonstrates that working memory dynamics operating during serial data acquisition bias hypothesis generation. The presentation rate (and order) of a sequence of serially presented symptoms was manipulated to be either fast (180 ms per symptom) or slow (1,500 ms per symptom) in a simulated medical diagnosis task.
View Article and Find Full Text PDFCertain research tasks require extracting data points from graphs and charts. Using 91 graphs that presented results from single-case designs, we investigated whether pairs of coders extract similar data from the same graphs (reliability), and whether the extracted data match numerical descriptions of the graph that the original author may have presented in tables or text (validity). Coders extracted data using the UnGraph computer program.
View Article and Find Full Text PDFNear-infrared (NIR) spectroscopy calibrations that will allow prediction of the solid fat content (SFC) of milk fat extracted from butter by one measurement during manufacture were developed. SFC is a measure of the amount of the solid fraction of fat crystallized at a temperature expressed as a percentage (w/w). At-line SFC determinations are currently performed by nuclear magnetic resonance (NMR) spectroscopy, which involves a 16 h delay period for tempering of the milk fat at 0 degrees C prior to the SFC measurements, from 0 to 35 degrees C in a series of 5 degrees C increments.
View Article and Find Full Text PDFSmith-Lemli-Opitz syndrome (SLOS) is an inherited autosomal recessive cholesterol deficiency disorder. Our studies have shown that in SLOS children, urinary mevalonate excretion is normal and reflects hepatic HMG-CoA reductase activity but not ultimate sterol synthesis. Hence, we hypothesized that in SLOS there may be increased diversion of mevalonate to nonsterol isoprenoid synthesis.
View Article and Find Full Text PDFColesevelam HC1 is a potent bile acid-binding polymer. This study's aim was to determine effects of colesevelam HCl on sterol and bile acid excretion in patients with type IIa hypercholesterolemia. Twenty-four patients (low-density lipoprotein cholesterol, 130 to 220 mg/dL) enrolled in an open-label, parallel-design study, entered an American Heart Association/National Cholesterol Education Program diet for 6 weeks and were randomized to colesevelam HCl, 2.
View Article and Find Full Text PDFCoronary hyperreactivity (CH), characterized by persistent severe vasoconstrictions in response to vasoconstrictor challenge, is oppositely influenced by progesterone (P) and medroxyprogesterone acetate (MPA) treatment in surgically menopausal primates. In this study we tested whether multiweek MPA or dihydrotestosterone (DHT) exposure induced CH in intact male rhesus monkeys. Coronary angiographic experiments with intracoronary serotonin and the thromboxane A(2) analog U46619 stimulated brief vasoconstriction (for 1-3 min) in large epicardial coronaries in untreated male monkeys.
View Article and Find Full Text PDFObjective: To test if transdermal progesterone (P) confers coronary vascular protection in surgically menopausal preatherosclerotic rhesus monkeys.
Methods And Results: Ovariectomized rhesus monkeys fed an atherogenic diet (AD) for 19 months were treated with an investigational transdermal P cream (n=7) or identical placebo cream (n=5) for 4 weeks. Aorta and carotids showed fatty streaks and Oil Red O staining demonstrated lipid deposition.
Evidence that CHD morbidity and mortality can be reduced with reduction of LDL-C to less than 100 mg/dL (2.6 mmol/L) is rapidly accumulating. NCEP-ATP III guidelines should be considered minimal goals of therapy.
View Article and Find Full Text PDF3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibitors are widely used to decrease plasma cholesterol levels in patients with heterozygous familial hypercholesterolemia (FH) who are at increased risk of premature coronary artery disease. Tissue-culture and animal studies have indicated that administration of HMG CoA reductase inhibitors (eg, lovastatin, simvastatin, etc) induces a compensatory increase in the activity of HMG CoA reductase, both by increasing its synthesis and decreasing catabolism. To determine in human subjects whether cessation of therapy with this class of drugs leads to induction of HMG CoA reductase activity and above-normal rates of cholesterol biosynthesis, we measured urinary concentrations of mevalonic acid (an indicator of cholesterol biosynthesis) after the cessation of therapy with lovastatin and simvastatin (80 mg/day) in patients with heterozygous FH.
View Article and Find Full Text PDFSmith-Lemli-Opitz syndrome (SLOS) is a genetic disorder characterized by low plasma cholesterol and high 7-dehydrocholesterol (7-DHC). Synthesis of cholesterol and 7-DHC and its metabolites is regulated by HMG-CoA reductase, whose activity can be measured by 24-h excretion of its product mevalonate. We devised a simple, non-invasive method for collecting 24-h urine in our subjects.
View Article and Find Full Text PDFAnimal and human studies have shown that the biosynthesis of cholesterol exhibits diurnal periodicity with nocturnal increases in the level of cholesterol precursors. Dietary cholesterol, which increases the intracellular pool of cholesterol and plasma cholesterol levels, has been shown to blunt the nocturnal increases in cholesterol biosynthesis. Patients with heterozygous familial hypercholesterolemia (FH) have very high levels of plasma low-density lipoprotein cholesterol (LDL) due to their reduced ability to metabolize LDL particles.
View Article and Find Full Text PDFThe increased risk of coronary artery disease among patients with diabetes mellitus is attributable, in part, to specific disorders of lipoprotein metabolism that are common in this population. These include disordered metabolism of very-low-density lipoprotein and/or chylomicrons that may be proatherogenic. Elevated postprandial triglycerides, peak postprandial triglyceridemia, and late postprandial triglyceride levels have been associated in clinical trials with both early coronary artery and carotid artery atherosclerosis for persons with normal lipid profiles and those with mild-to-moderate hyperlipidemia, independently of established risk factors.
View Article and Find Full Text PDFObjective: At higher doses, simvastatin has been shown to produce significantly greater increases in high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-I than atorvastatin. To extend and confirm these findings, a 36-week, randomized, double-blind, dose-titration study was performed in 826 hypercholesterolemic patients to compare the effects of simvastatin and atorvastatin on HDL cholesterol, apo A-I, and clinical and laboratory safety. PRIMARY HYPOTHESIS: Simvastatin, across a range of doses, will be more effective than atorvastatin at raising HDL cholesterol and apo A-I levels.
View Article and Find Full Text PDFWe tested the effects of feeding a diet very high in fiber from fruit and vegetables. The levels fed were those, which had originally inspired the dietary fiber hypothesis related to colon cancer and heart disease prevention and also may have been eaten early in human evolution. Ten healthy volunteers each took 3 metabolic diets of 2 weeks duration.
View Article and Find Full Text PDFAbetalipoproteinemia (ABL) is an inherited disease characterized by the virtual absence of apolipoprotein B (apoB)-containing lipoproteins from plasma. Only limited numbers of families have been screened for mutations in the microsomal triglyceride transfer protein (MTP) gene. To clarify the genetic basis of clinical diversity of ABL, mutations of the MTP gene have been screened in 4 unrelated patients with ABL.
View Article and Find Full Text PDFPatients with homozygous familial hypercholesterolaemia (HoFH) have markedly elevated low density lipoprotein (LDL) cholesterol levels that are refractory to standard doses of lipid-lowering drug therapy. In the present study we evaluated the effect of atorvastatin on steady state concentrations of plasma lipids and mevalonic acid (MVA), as well as on 24-h urinary excretion of MVA in patients with well characterized HoFH. Thirty-five HoFH patients (18 males; 17 females) received 40 mg and then 80 mg atorvastatin/day.
View Article and Find Full Text PDFBenefit from the treatment of hyperlipidemia has now been conclusively documented, and this article has focused on the clinical trial data supporting diet and drug therapy in adult patients with different lipoprotein disorders and discussed therapeutic approaches with a focus on reducing plasma concentrations of LDL cholesterol. National guidelines for the use of hypolipidemic drugs are strongly supported by the clinical trials and have appropriately set lower target concentrations of LDL cholesterol for patients with established atherosclerosis or diabetic patients as compared with patients with more than two cardiovascular risk factors or, the lowest risk group, patients without evidence of atherosclerosis and fewer than two known cardiovascular risk factors. The goals of therapy in patients with established atherosclerosis are to prevent further progression and potentially induce regression, whereas in high-risk patients (e.
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