Drugs online research references
vision.eri.harvard.edu
BACKGROUND: Many older adults have lost the use of their foveae due to disease. Because of this, they must use peripheral retina to do tasks formerly done using the fovea, such as letter identification and reading. Several researchers have recently proposed that reading in the periphery is limited by lateral masking: the reduced perceptibility of a target when it is surrounded by flanking stimuli. None of these studies tested the perceptibility of letters within words, where the semantic relationship between the target letter and the flanking letters is likely to improve perceptibility. This study sought to determine whether the semantic relationship between the flanking stimuli and the target stimulus affects perceptibility of letters in the periphery. METHODS: Young, normally-sighted observers identified single letters and the middle letters of three-letter words, trigrams, and letters flanked by x's (xax) presented for 150 ms at 10 degrees eccentricity on each of the primary meridia. In the first experiment, subjects identified letters presented alone and letters flanked by one x on either side. In the second experiment, subjects identified the middle letters of words, trigrams, and xax stimuli, which were either presented in blocks or randomly. In the third experiment, only the words and trigrams were used, and subjects were required to both identify the middle letter and simultaneously indicate whether the stimulus was a word or a trigram. RESULTS: The first experiment showed that single letters were identified about 50% more accurately than letters flanked by x's. In the second and third experiments, letter identification was better when the target and flanking letters formed a word than when they formed a trigram and better along the horizontal meridian than along the vertical meridian, which is consistent with previous studies. In the third experiment, the subject's ability to identify the stimulus type had a significant impact on performance. When the stimuli were words, subjects identified the middle letter on 87% of trials when they correctly identified the stimulus and 40% of the trials when they did not; for the trigrams these percentages were 65% and 5%. CONCLUSIONS: When the flanking letters and the target letter formed a word, observers were better able to identify the target than when they did not form a word, and this pattern was mediated by the observers' knowledge of stimulus type. These data suggest that to draw conclusions regarding the impact of lateral masking on reading, the stimuli used should be words, not random-letter strings or other target/flanker combinations.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11763257&dopt=Abstract
hotmail.com
PURPOSE: Previous studies on the optical components of childhood myopia adjusted only for age and gender or reported only the change of individual components with time. We perform a study to assess the association of the optical components of the eye contributing to the degree of myopia by building a statistical model which can better assess the individual effects of each optical component. METHODS: Children 6-12 years old with myopia of -1 to -6 D were used in this study. Autokeratometry was performed to determine the mean corneal power in two perpendicular meridia. Ultrasonography was used to determine the vitreous chamber depth (VCD). Ultrasonography and Scheimflug biometry were used to determine lens thickness (LT) and anterior chamber depth. A stepwise multiple linear regression was used to determine statistically significant independent variables that explain the variation in the mean spherical equivalent of the left eye. The independent variables investigated were anterior chamber length, LT, VCD, mean corneal power, age and gender. The first regression model used measurements of anterior chamber depth and LT from ultrasonography, while the second model used measurements from Scheimflug photography. Statistical significance was set at p < 0.05. RESULTS: Both statistical models have the same significant independent variables - VCD, LT and gender, with similar estimates. In both models, VCD was found to have the strongest partial association with mean spherical equivalent, followed by gender and LT. A more myopic refractive error was associated with (1) a longer eye, (2) an increased LT, and (3) female gender. CONCLUSIONS: Myopia was associated with a longer vitreous chamber. This remained the primary determinant of myopia in Chinese children after consideration of other optical components. The effect of gender and LT on myopia requires further study. These results are in agreement with multiple regression analyses in Singapore adults.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11824645&dopt=Abstract
hotmail.com
A growing number of obese people throughout the world have become a health-economic problem. Obesity and overweight are significant risk factors causing increased morbidity and mortality in obese people. Nevertheless, a marked improvement in the prognosis is achieved by a 5-10% decrease in body weight. Since 1 July 2002, two preparations for long-term therapy of obesity have been registered in the Czech Republic: Xenical (orlistat) and Meridia (sibutramin). Long-term randomized double-blind studies have shown that a decrease of 4.4 kg in weight within a year is achieved by 10 mg sibutramin administration, a decrease of 3.2-6.4 kg in weight within a year is achieved by 15 mg sibutramin administration, a decrease of 7.4-9.1 kg in weight within a year is achieved by orlistat administration, and placebo administration causes changes in weight ranging from -6.5 kg to +0.94 kg. A cost-to-effectiveness comparison has revealed that in one year the direct costs (ORC) of a decrease in body weight by 1 kg after deduction of the placebo effect make 9,817 CZK to 22,078 CZK (the supplementary payment of the patient being 2698 CZK to 7722 CZK) in sibutramin treatment, and 9101 CZK to 13,085 CZK (the supplementary payment of the patient being 632 CZK to 909 CZK) in orlistat treatment.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14619705&dopt=Abstract
online pharmacies ||
Hair Million herbal formula for hair loss and hair growth ||
Amoxicillin ||
Tramadol ||
Paxil ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Zithromax ||
online pharmacy ||
Antibiotics and prescription medications online literature ||
Antibiotics