14 research outputs found

    Using a Responsive Survey Design to Innovate Self-Administered Mixed-Mode Surveys

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    Implementing innovations in surveys often results in uncertainty concerning how different design decisions will affect key performance indicators such as response rates, nonresponse bias, or survey costs. Thus, responsive survey designs have been developed to better cope with such situations. In the present study, we propose a responsive survey design that relies on experimentation in the earlier phases of the survey to decide between different design choices of which - prior to data collection - their impact on performance indicators is uncertain. We applied this design to the European Values Study 2017/2018 in Germany that advanced its general social survey-type design away from the traditional face-to-face mode to self-administered modes. These design changes resulted in uncertainty as to how different incentive strategies and mode choice sequences would affect response rates, nonresponse bias, and survey costs. We illustrate the application and operation of the proposed responsive survey design, as well as an efficiency issue that accompanies it. We also compare the performance of the responsive survey design to a traditional survey design that would have kept all design characteristics static during the field period

    Silencing of the Violaxanthin De-Epoxidase Gene in the Diatom Phaeodactylum tricornutum Reduces Diatoxanthin Synthesis and Non-Photochemical Quenching

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    Diatoms are a major group of primary producers ubiquitous in all aquatic ecosystems. To protect themselves from photooxidative damage in a fluctuating light climate potentially punctuated with regular excess light exposures, diatoms have developed several photoprotective mechanisms. The xanthophyll cycle (XC) dependent non-photochemical chlorophyll fluorescence quenching (NPQ) is one of the most important photoprotective processes that rapidly regulate photosynthesis in diatoms. NPQ depends on the conversion of diadinoxanthin (DD) into diatoxanthin (DT) by the violaxanthin de-epoxidase (VDE), also called DD de-epoxidase (DDE). To study the role of DDE in controlling NPQ, we generated transformants of P. tricornutum in which the gene (Vde/Dde) encoding for DDE was silenced. RNA interference was induced by genetic transformation of the cells with plasmids containing either short (198 bp) or long (523 bp) antisense (AS) fragments or, alternatively, with a plasmid mediating the expression of a self-complementary hairpin-like construct (inverted repeat, IR). The silencing approaches generated diatom transformants with a phenotype clearly distinguishable from wildtype (WT) cells, i.e. a lower degree as well as slower kinetics of both DD de-epoxidation and NPQ induction. Real-time PCR based quantification of Dde transcripts revealed differences in transcript levels between AS transformants and WT cells but also between AS and IR transformants, suggesting the possible presence of two different gene silencing mediating mechanisms. This was confirmed by the differential effect of the light intensity on the respective silencing efficiency of both types of transformants. The characterization of the transformants strengthened some of the specific features of the XC and NPQ and confirmed the most recent mechanistic model of the DT/NPQ relationship in diatoms

    Prevalence of Age-Related Macular Degeneration in Europe: The Past and the Future

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    Purpose Age-related macular degeneration (AMD) is a frequent, complex disorder in elderly of European ancestry. Risk profiles and treatment options have changed considerably over the years, which may have affected disease prevalence and outcome. We determined the prevalence of early and late AMD in Europe from 1990 to 2013 using the European Eye Epidemiology (E3) consortium, and made projections for the future. Design Meta-analysis of prevalence data. Participants A total of 42 080 individuals 40 years of age and older participating in 14 population-based cohorts from 10 countries in Europe. Methods AMD was diagnosed based on fundus photographs using the Rotterdam Classification. Prevalence of early and late AMD was calculated using random-effects meta-analysis stratified for age, birth cohort, gender, geographic region, and time period of the study. Best-corrected visual acuity (BCVA) was compared between late AMD subtypes; geographic atrophy (GA) and choroidal neovascularization (CNV). Main Outcome Measures Prevalence of early and late AMD, BCVA, and number of AMD cases. Results Prevalence of early AMD increased from 3.5% (95% confidence interval [CI] 2.1%–5.0%) in those aged 55–59 years to 17.6% (95%

    Cerebellar Cognitive Affective Syndrome and Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay:A Report of Two Male Sibs

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    Item does not contain fulltextBackground: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare neurodegenerative disorder caused by mutations in the SACS gene (13q12) encoding the protein sacsin. It is characterized by early-onset cerebellar ataxia, lower limb spasticity, sensorimotor axonal polyneuropathy, and atrophy of the superior cerebellar vermis. Cerebellar disorders in general may be accompanied by the cerebellar cognitive affective syndrome (CCAS) which presents with disturbances of executive functioning, spatial cognition, linguistic capacities, and affect. Sampling and Methods: Two middle-aged brothers with ARSACS, one of whom was referred for behavioral disinhibition, are described. A detailed neuropsychiatric and neuropsychological assessment was performed. Results: Apart from motor symptoms, motivational deficits along with cognitive and behavioral dysfunctions were present; these were much more pronounced in the older sib. Conclusions: These observations add to the literature which suggests that the cerebellum, apart from its significance for motor behavior, plays a functional role in human cognition and affect. The nonmotor symptoms of ARSACS are discussed in terms of the CCAS.7 p

    Efficacy and Safety of a Tight Glucose Control Protocol in Critically Ill Term Neonates

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    Background: A large single-center randomized trial showed that treating hyperglycemia in critically ill children improved outcome, despite an increased incidence of hypoglycemia, especially in infants. Objectives: We evaluated the efficacy and incidence of hypoglycemia using a tight glucose protocol in critically ill term neonates. Methods: Term hyperglycemic (>8 mmol·l -1; >144 mg·dl -1) neonates treated with a tight glucose protocol during a 3.5-year period

    Reducing glucose infusion safely prevents hyperglycemia in post-surgical children

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    SummaryBackground & aimsTo investigate the effects of two different glucose infusions on glucose homeostasis and amino acid metabolism in post-surgical children.MethodsThis randomized crossover study evaluated glucose and amino acid metabolism in eight children (age 9.8 ± 1.9 months, weight 9.5 ± 1.1 kg) admitted to a pediatric intensive care unit in a tertiary university hospital after surgical correction for non-syndromal craniosynostosis. Patients were randomized to receive low (LG; 2.5 mg kg−1 min−1) and standard (SG; 5.0 mg kg−1 min−1) glucose infusion in a crossover setting. After a bolus (4 g kg−1) of deuterium oxide, we conducted a primed, constant, 8 h tracer infusion with [6,6-2H2]Glucose, [1-13C]Leucine, [ring-2H5]Phenylalanine and [3,3-2H2]Tyrosine.ResultsSG resulted in hyperglycemia (defined as > 6.1 mmol L−1), while during LG plasma glucose levels were normoglycemic (5.9 ± 0.6 vs. 7.5 ± 1.7 mmol L−1; LG vs. SG respectively, p = 0.02). Hypoglycemia did not occur during LG infusion. Endogenous glucose production was not fully suppressed during the hyperglycemic state under SG and increased with reduced glucose infusion (2.6 ± 1.5 vs. 1.1 ± 1.4 mg kg−1 min−1; LG vs. SG; p = 0.05). Whole body protein balance derived from leucine and phenylalanine kinetics was slightly negative but not further affected with a decrease in glucose infusion.ConclusionsThe current recommended glucose infusion induces hyperglycemia in post-surgical children. A reduced glucose infusion safely reduced high glucose levels, while children were capable to sustain normoglycemia with increased endogenous glucose production. The reduced glucose infusion did not exacerbate the mild catabolic state in which the patients were

    Increased High-Density Lipoprotein Levels Associated with Age-Related Macular Degeneration: Evidence from the EYE-RISK and European Eye Epidemiology Consortia

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    Purpose: Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset. Design: Pooled analysis of cross-sectional data. Participants: Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data. Methods: AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations. Main Outcome Measures: AMD features and stage; lipid measurements. Results: HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14–1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91–0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10–1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10 –7 ), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10 –6 and P = 1.6 × 10 –4 ). Conclusions: Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered

    Increased high-density lipoprotein levels associated with age-related macular degeneration: Evidence from the EYE-RISK and European Eye Epidemiology Consortia

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    Purpose: Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset. Design: Pooled analysis of cross-sectional data. Participants: Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data. Methods: AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations. Main Outcome Measures: AMD features and stage; lipid measurements. Results: HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14–1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91–0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10–1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10 –7 ), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10 –6 and P = 1.6 × 10 –4 ). Conclusions: Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered. </p
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