75 resultados para label switching
Resumo:
In this study we investigated whether synesthetic color experiences have similar effects as real colors in cognitive conflict adaptation. We tested 24 synesthetes and two yoke-matched control groups in a task-switching experiment that involved regular switches between three simple decision tasks (a color decision, a form decision, and a size decision). In most of the trials the stimuli were univalent, that is, specific for each task. However, occasionally, black graphemes were presented for the size decisions and we tested whether they would trigger synesthetic color experiences and thus, turn them into bivalent stimuli. The results confirmed this expectation. We were also interested in their effect for subsequent performance (i.e., the bivalency effect). The results showed that for synesthetic colors the bivalency effect was not as pronounced as for real colors. The latter result may be related to differences between synesthetes and controls in coping with color conflict.
Resumo:
2-Aminopurine (2AP) is a fluorescent isomer of adenine and has a fluorescence lifetime of ~11 ns in water. It is widely used in biochemical settings as a site-specific fluorescent probe of DNA and RNA structure and base-flipping and -folding. These assays assume that 2AP is intrinsically strongly fluorescent. Here, we show this not to be the case, observing that gas-phase, jet-cooled 2-aminopurine and 9-methyl-2-aminopurine have very short fluorescence lifetimes (156 ps and 210 ps, respectively); they are, to all intents and purposes, non-fluorescent. We find that the lifetime of 2-aminopurine increases dramatically when it is part of a hydrate cluster, 2AP·(H2O)n, where n = 1–3. Not only does it depend on the presence of water molecules, it also depends on the specific hydrogen-bonding site to which they attach and on the number of H2O molecules at that site. We selectively microhydrate 2-aminopurine at its sugar-edge, cis-amino or trans-amino sites and see that its fluorescence lifetime increases by 4, 50 and 95 times (to 14.5 ns), respectively.
Resumo:
BACKGROUND HIV-1 viral load (VL) testing is recommended to monitor antiretroviral therapy (ART) but not universally available. We examined monitoring of first-line and switching to second-line ART in sub-Saharan Africa, 2004-2013. METHODS Adult HIV-1 infected patients starting combination ART in 16 countries were included. Switching was defined as a change from a non-nucleoside reverse-transcriptase inhibitor (NNRTI)-based regimen to a protease inhibitor (PI)-based regimen, with a change of ≥1 NRTI. Virological and immunological failures were defined per World Health Organization criteria. We calculated cumulative probabilities of switching and hazard ratios with 95% confidence intervals (CI) comparing routine VL monitoring, targeted VL monitoring, CD4 cell monitoring and clinical monitoring, adjusted for programme and individual characteristics. FINDINGS Of 297,825 eligible patients, 10,352 patients (3·5%) switched during 782,412 person-years of follow-up. Compared to CD4 monitoring hazard ratios for switching were 3·15 (95% CI 2·92-3·40) for routine VL, 1·21 (1·13-1·30) for targeted VL and 0·49 (0·43-0·56) for clinical monitoring. Overall 58.0% of patients with confirmed virological and 19·3% of patients with confirmed immunological failure switched within 2 years. Among patients who switched the percentage with evidence of treatment failure based on a single CD4 or VL measurement ranged from 32·1% with clinical to 84.3% with targeted VL monitoring. Median CD4 counts at switching were 215 cells/µl under routine VL monitoring but lower with other monitoring (114-133 cells/µl). INTERPRETATION Overall few patients switched to second-line ART and switching occurred late in the absence of routine viral load monitoring. Switching was more common and occurred earlier with targeted or routine viral load testing.
Resumo:
The concentration of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THCCOOH) in whole blood is used as a parameter for assessing the consumption behavior of cannabis consumers. The blood level of THCCOOH-glucuronide might provide additional information about the frequency of cannabis use. To verify this assumption, a column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and direct quantification of free and glucuronidated THCCOOH in human whole blood was newly developed. The method comprised protein precipitation, followed by injection of the processed sample onto a trapping column and subsequent gradient elution to an analytical column for separation and detection. The total LC run time was 4.5 min. Detection of the analytes was accomplished by electrospray ionization in positive ion mode and selected reaction monitoring using a triple-stage quadrupole mass spectrometer. The method was fully validated by evaluating the following parameters: linearity, lower limit of quantification, accuracy and imprecision, selectivity, extraction efficiency, matrix effect, carry-over, dilution integrity, analyte stability, and re-injection reproducibility. All acceptance criteria were analyzed and the predefined criteria met. Linearity ranged from 5.0 to 500 μg/L for both analytes. The method was successfully applied to whole blood samples from a large collective of cannabis consumers, demonstrating its applicability in the forensic field.
Resumo:
Limited data exist on the efficacy of long-term therapies for osteoporosis. In osteoporotic postmenopausal women receiving denosumab for 7 years, nonvertebral fracture rates significantly decreased in years 4-7 versus years 1-3. This is the first demonstration of a further benefit on fracture outcomes with long-term therapy for osteoporosis. INTRODUCTION This study aimed to evaluate whether denosumab treatment continued beyond 3 years is associated with a further reduction in nonvertebral fracture rates. METHODS Participants who completed the 3-year placebo-controlled Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months (FREEDOM) study were invited to participate in an open-label extension. The present analysis includes 4,074 postmenopausal women with osteoporosis (n = 2,343 long-term; n = 1,731 cross-over) who enrolled in the extension, missed ≤1 dose during their first 3 years of denosumab treatment, and continued into the fourth year of treatment. Comparison of nonvertebral fracture rates during years 1-3 of denosumab with that of the fourth year and with the rate during years 4-7 was evaluated. RESULTS For the combined group, the nonvertebral fracture rate per 100 participant-years was 2.15 for the first 3 years of denosumab treatment (referent) and 1.36 in the fourth year (rate ratio [RR] = 0.64; 95 % confidence interval (CI) = 0.48 to 0.85, p = 0.003). Comparable findings were observed in the groups separately and when nonvertebral fracture rates during years 1-3 were compared to years 4-7 in the long-term group (RR = 0.79; 95 % CI = 0.62 to 1.00, p = 0.046). Fracture rate reductions in year 4 were most prominent in subjects with persisting low hip bone mineral density (BMD). CONCLUSIONS Denosumab treatment beyond 3 years was associated with a further reduction in nonvertebral fracture rate that persisted through 7 years of continuous denosumab administration. The degree to which denosumab further reduces nonvertebral fracture risk appears influenced by the hip bone density achieved with initial therapy.
Resumo:
BACKGROUND Buruli ulcer (BU) is a necrotizing skin disease most prevalent among West African children. The causative organism, Mycobacterium ulcerans, is sensitive to temperatures above 37°C. We investigated the safety and efficacy of a local heat application device based on phase change material. METHODS In a phase II open label single center noncomparative clinical trial (ISRCTN 72102977) under GCP standards in Cameroon, laboratory confirmed BU patients received up to 8 weeks of heat treatment. We assessed efficacy based on the endpoints 'absence of clinical BU specific features' or 'wound closure' within 6 months ("primary cure"), and 'absence of clinical recurrence within 24 month' ("definite cure"). RESULTS Of 53 patients 51 (96%) had ulcerative disease. 62% were classified as World Health Organization category II, 19% each as category I and III. The average lesion size was 45 cm(2). Within 6 months after completion of heat treatment 92.4% (49 of 53, 95% confidence interval [CI], 81.8% to 98.0%) achieved cure of their primary lesion. At 24 months follow-up 83.7% (41 of 49, 95% CI, 70.3% to 92.7%) of patients with primary cure remained free of recurrence. Heat treatment was well tolerated; adverse effects were occasional mild local skin reactions. CONCLUSIONS Local thermotherapy is a highly effective, simple, cheap and safe treatment for M. ulcerans disease. It has in particular potential as home-based remedy for BU suspicious lesions at community level where laboratory confirmation is not available. CLINICAL TRIALS REGISTRATION ISRCT 72102977.
Resumo:
Faldaprevir, a hepatitis C virus (HCV) NS3/4A protease inhibitor, was evaluated in HCV genotype 1-infected patients who failed peginterferon and ribavirin (PegIFN/RBV) treatment during one of three prior faldaprevir trials. Patients who received placebo plus PegIFN/RBV and had virological failure during a prior trial were enrolled and treated in two cohorts: prior relapsers (n = 43) and prior nonresponders (null responders, partial responders and patients with breakthrough; n = 75). Both cohorts received faldaprevir 240 mg once daily plus PegIFN/RBV for 24 weeks. Prior relapsers with early treatment success (ETS; HCV RNA <25 IU/mL detectable or undetectable at week 4 and <25 IU/mL undetectable at week 8) stopped treatment at week 24. Others received PegIFN/RBV through week 48. The primary efficacy endpoint was sustained virological response (HCV RNA <25 IU/mL undetectable) 12 weeks post treatment (SVR12). More prior nonresponders than prior relapsers had baseline HCV RNA ≥800 000 IU/mL (80% vs 58%) and a non-CC IL28B genotype (91% vs 70%). Rates of SVR12 (95% CI) were 95.3% (89.1, 100.0) among prior relapsers and 54.7% (43.4, 65.9) among prior nonresponders; corresponding ETS rates were 97.7% and 65.3%. Adverse events led to faldaprevir discontinuations in 3% of patients. The most common Division of AIDS Grade ≥2 adverse events were anaemia (13%), nausea (10%) and hyperbilirubinaemia (9%). In conclusion, faldaprevir plus PegIFN/RBV achieved clinically meaningful SVR12 rates in patients who failed PegIFN/RBV in a prior trial, with response rates higher among prior relapsers than among prior nonresponders. The adverse event profile was consistent with the known safety profile of faldaprevir.
Resumo:
OBJECTIVE The aim of this cross-sectional study was to estimate bone loss of implants with platform-switching design and analyze possible risk indicators after 5 years of loading in a multi-centered private practice network. METHOD AND MATERIALS Peri-implant bone loss was measured radiographically as the distance from the implant shoulder to the mesial and distal alveolar crest, respectively. Risk factor analysis for marginal bone loss included type of implant prosthetic treatment concept and dental status of the opposite arch. RESULTS A total of 316 implants in 98 study patients after 5 years of loading were examined. The overall mean value for radiographic bone loss was 1.02 mm (SD ± 1.25 mm, 95% CI 0.90- 1.14). Correlation analyses indicated a strong association of peri-implant bone loss > 2 mm for removable implant-retained prostheses with an odds ratio of 53.8. CONCLUSION The 5-year-results of the study show clinically acceptable values of mean bone loss after 5 years of loading. Implant-supported removable prostheses seem to be a strong co-factor for extensive bone level changes compared to fixed reconstructions. However, these results have to be considered for evaluation of the included special cohort under private dental office conditions.
Resumo:
OBJECTIVE In Europe, growth hormone (GH) treatment for children born small for gestational age (SGA) can only be initiated after 4 years of age. However, younger age at treatment initiation is a predictor of favourable response. To assess the effect of GH treatment on early growth and cognitive functioning in very young (<30 months), short-stature children born SGA. DESIGN A 2-year, randomized controlled, multicentre study (NCT00627523; EGN study), in which patients received either GH treatment or no treatment for 24 months. PATIENTS Children aged 19-29 months diagnosed as SGA at birth, and for whom sufficient early growth data were available, were eligible. Patients were randomized (1:1) to GH treatment (Genotropin(®) , Pfizer Inc.) at a dose of 0·035 mg/kg/day by subcutaneous injection, or no treatment. MEASUREMENTS The primary objective was to assess the change from baseline in height standard deviation score (SDS) after 24 months of GH treatment. RESULTS Change from baseline in height SDS was significantly greater in the GH treatment vs control group at both month 12 (1·03 vs 0·14) and month 24 (1·63 vs 0·43; both P < 0·001). Growth velocity SDS was significantly higher in the GH treatment vs control group at 12 months (P < 0·001), but not at 24 months. There was no significant difference in mental or psychomotor development indices between the two groups. CONCLUSIONS GH treatment for 24 months in very young short-stature children born SGA resulted in a significant increase in height SDS compared with no treatment.
Resumo:
The goal of the present thesis was to investigate the production of code-switched utterances in bilinguals’ speech production. This study investigates the availability of grammatical-category information during bilingual language processing. The specific aim is to examine the processes involved in the production of Persian-English bilingual compound verbs (BCVs). A bilingual compound verb is formed when the nominal constituent of a compound verb is replaced by an item from the other language. In the present cases of BCVs the nominal constituents are replaced by a verb from the other language. The main question addressed is how a lexical element corresponding to a verb node can be placed in a slot that corresponds to a noun lemma. This study also investigates how the production of BCVs might be captured within a model of BCVs and how such a model may be integrated within incremental network models of speech production. In the present study, both naturalistic and experimental data were used to investigate the processes involved in the production of BCVs. In the first part of the present study, I collected 2298 minutes of a popular Iranian TV program and found 962 code-switched utterances. In 83 (8%) of the switched cases, insertions occurred within the Persian compound verb structure, hence, resulting in BCVs. As to the second part of my work, a picture-word interference experiment was conducted. This study addressed whether in the case of the production of Persian-English BCVs, English verbs compete with the corresponding Persian compound verbs as a whole, or whether English verbs compete with the nominal constituents of Persian compound verbs only. Persian-English bilinguals named pictures depicting actions in 4 conditions in Persian (L1). In condition 1, participants named pictures of action using the whole Persian compound verb in the context of its English equivalent distractor verb. In condition 2, only the nominal constituent was produced in the presence of the light verb of the target Persian compound verb and in the context of a semantically closely related English distractor verb. In condition 3, the whole Persian compound verb was produced in the context of a semantically unrelated English distractor verb. In condition 4, only the nominal constituent was produced in the presence of the light verb of the target Persian compound verb and in the context of a semantically unrelated English distractor verb. The main effect of linguistic unit was significant by participants and items. Naming latencies were longer in the nominal linguistic unit compared to the compound verb (CV) linguistic unit. That is, participants were slower to produce the nominal constituent of compound verbs in the context of a semantically closely related English distractor verb compared to producing the whole compound verbs in the context of a semantically closely related English distractor verb. The three-way interaction between version of the experiment (CV and nominal versions), linguistic unit (nominal and CV linguistic units), and relation (semantically related and unrelated distractor words) was significant by participants. In both versions, naming latencies were longer in the semantically related nominal linguistic unit compared to the response latencies in the semantically related CV linguistic unit. In both versions, naming latencies were longer in the semantically related nominal linguistic unit compared to response latencies in the semantically unrelated nominal linguistic unit. Both the analysis of the naturalistic data and the results of the experiment revealed that in the case of the production of the nominal constituent of BCVs, a verb from the other language may compete with a noun from the base language, suggesting that grammatical category does not necessarily provide a constraint on lexical access during the production of the nominal constituent of BCVs. There was a minimal context in condition 2 (the nominal linguistic unit) in which the nominal constituent was produced in the presence of its corresponding light verb. The results suggest that generating words within a context may not guarantee that the effect of grammatical class becomes available. A model is proposed in order to characterize the processes involved in the production of BCVs. Implications for models of bilingual language production are discussed.