6 research outputs found
Analysis of the mechanical impedance of bone-anchored hearing aids
Some patients who need hearing aids are unable to use an apparatus which transmits the sound via the external ear canal and have to use a bone conduction hearing aid. The bone vibration transducer of this aid is applied to the skin over the mastoid process and the sound is transmitted via the soft tissue and bone to the cochlea. The pressure needed to apply the transducer often gives the patient discomfort and the damping effect of the soft tissue gives poor quality of the sound transmitted. Advances in the ability to permanently implant foreign material in the body and perform permanent skin penetration has made it possible to develop a bone-anchored hearing aid. Fourteen patients have been equipped with such hearing aids. To be able to give these patients the best hearing aid, a new transducer has to be constructed to match the new situation. The impedance of the bone-anchored titaniumscrew/skull has been studied and the resistance and reactance of the mechanical impedance have been measured. The influence of a damping soft tissue layer over the bone has been analyzed. The difference between the impedance of the skull and the impedance of the soft tissue + skull was in the order of 10 to 25 dB depending on the frequency
Cuticle and cuticular wax development in the sunflower (Helianthus annuus L.) pericarp grown at the field under a moderate water deficit
Fruit development of two high oleic safflower (Carthamus tinctorius L.) cultivars
The purpose of this study was to describe fruit development in two high oleic safflower (Carthamus tinctorius L.) cultivars during four growing seasons. Pericarp histogenesis, and dynamics of pericarp and seed dry weight and fruit water content were studied.
The dynamics of the pericarp and seed growth was similar between cultivars and years. The pericarp completed its growth before the seed. Pericarp potential size was already set at anthesis as no cell division was observed at this time. Maximum pericarp dry weight was achieved 8 days after anthesis, when cell wall lignification concluded.
At this time, twinned prismatic simetric crystals had decreased in number and size respect to those observed at anthesis. Physiological maturity (maximum seed dry weight) was achieved between 17 and 25 days after anthesis. Similar pericarp growth rate and duration between cultivars and years were associated to similar maximum pericarp dry weight (17 mg), except in 2012. In this year, the higher maximum pericarp dry weight (20 mg) was only associated to a higher fruit volume (50 µL). Maximum seed dry weight (22 mg) was lower in CW88 OL than in CW99 OL, except in 2012. However, seed growth rate and time of physiological maturity were similar between cultivars. Fruit water content at physiological maturity (39%) was similar between cultivars. The recommended moisture (10-13%) at harvesting was achieved around 33 days after anthesis. The timing of the different morphological and histological events of safflower fruit development presented in this work sets a not-yet-existent conceptual framework, and constitutes an important tool for the interpretation and comparison of the effects of genotype, environment or agricultural management practices on crop yield and fruit quality.El objetivo de este trabajo fue describir el desarrollo del fruto de dos cultivares de cártamo (Carthamus tinctorius L.) alto oleico durante cuatro estaciones de crecimiento. Se estudió la histogénesis del pericarpio, y la dinámica del peso seco del pericarpio y de la semilla y del contenido de agua del fruto. La dinámica del crecimiento del pericarpio y de la semilla fue similar entre cultivares y años. El pericarpio completó su crecimiento antes que la semilla. El tamaño potencial del pericarpio ya estaba fijado en antesis ya que en ese momento no se observaron divisiones celulares. El máximo peso seco del pericarpio se alcanzó 8 días después de la antesis, momento en el que concluyó la lignificación de sus células. Al mismo tiempo, los pares de cristales prismáticos y simétricos habían disminuido en número y tamaño respecto de los observados en antesis. La madurez fisiológica (máximo peso seco de la semilla) se alcanzó entre los 17 y 25 días después de la antesis. La duración y tasa de crecimiento del pericarpio similares entre cultivares y años estuvieron asociadas a un similar máximo peso seco del pericarpio (17 mg), excepto en 2012. En este año, el mayor máximo peso seco del pericarpio (20 mg) estuvo únicamente asociado al mayor volumen del fruto (50 µL). El máximo peso seco de la semilla (22 mg) fue menor en CW88 OL respecto de CW99 OL, excepto en 2012.
Sin embargo, la tasa de crecimiento de la semilla y el tiempo en que se alcanzó la madurez fisiológica fueron similares entre cultivares. El contenido de agua del fruto en madurez fisiológica (39%) fue similar entre cultivares. El porcentaje de humedad del fruto recomendado para la cosecha (10-13%) se alcanzó alrededor de los 33 días después de la antesis. El momento en que ocurren los diferentes eventos morfológicos e histológicos del desarrollo del fruto de cártamo presentados en este trabajo establece un marco conceptual inexistente, y constituye una herramienta importante para la interpretación y comparación del efecto del genotipo, el medio ambiente o las prácticas de manejo del cultivo sobre el rendimiento y la calidad del fruto de cártamo
Mendelian randomization study of adiposity-related traits and risk of breast, ovarian, prostate, lung and colorectal cancer
Background: Adiposity traits have been associated with risk of many cancers in observational studies, but whether these associations are causal is unclear. Mendelian randomization (MR) uses genetic predictors of risk factors as instrumental variables to eliminate reverse causation and reduce confounding bias. We performed MR analyses to assess the possible causal relationship of birthweight, childhood and adult body mass index (BMI), and waist-hip ratio (WHR) on the risks of breast, ovarian, prostate, colorectal and lung cancers. Methods: We tested the association between genetic risk scores and each trait using summary statistics from published genome-wide association studies (GWAS) and from 51 537 cancer cases and 61 600 controls in the Genetic Associations and Mechanisms in Oncology (GAME-ON) Consortium. Results: We found an inverse association between the genetic score for childhood BMI and risk of breast cancer [odds ratio (OR)=0.71 per standard deviation (s.d.) increase in childhood BMI; 95% confidence interval (CI): 0.60, 0.80; P=6.5
710-5). We also found the genetic score for adult BMI to be inversely associated with breast cancer risk (OR=0.66 per s.d. increase in BMI; 95% CI: 0.57, 0.77; P=2.5
710-7), and positively associated with ovarian cancer (OR=1.35; 95% CI: 1.05, 1.72; P=0.017), lung cancer (OR=1.27; 95% CI: 1.09, 1.49; P=2.9
710-3) and colorectal cancer (OR=1.39; 95% CI: 1.06, 1.82, P=0.016). The inverse association between genetically predicted adult BMI and breast cancer risk remained even after adjusting for directional pleiotropy via MR-Egger regression. Conclusions: Findings from this study provide additional understandings of the complex relationship between adiposity and cancer risks. Our results for breast and lung cancer are particularly interesting, given previous reports of effect heterogeneity by menopausal status and smoking status. \ua9 The Author 2016; Published by Oxford University Press on behalf of the International Epidemiological Association All rights reserved
Modeling Linkage Disequilibrium Increases Accuracy of Polygenic Risk Scores
Polygenic risk scores have shown great promise in predicting complex disease risk and will become more accurate as training sample sizes increase. The standard approach for calculating risk scores involves linkage disequilibrium (LD)-based marker pruning and applying a p\ua0value threshold to association statistics, but this discards information and can reduce predictive accuracy. We introduce LDpred, a method that infers the posterior mean effect size of each marker by using a prior on effect sizes and LD information from an external reference panel. Theory and simulations show that LDpred outperforms the approach of pruning followed by thresholding, particularly at large sample sizes. Accordingly, predicted R(2) increased from 20.1% to 25.3% in a large schizophrenia dataset and from 9.8% to 12.0% in a large multiple sclerosis dataset. A similar relative improvement in accuracy was observed for three additional large disease datasets and for non-European schizophrenia samples. The advantage of LDpred over existing methods will grow as sample sizes increase
Candida bloodstream infections in intensive care units: analysis of the extended prevalence of infection in intensive care unit study
To provide a global, up-to-date picture of the prevalence, treatment, and outcomes of Candida bloodstream infections in intensive care unit patients and compare Candida with bacterial bloodstream infection.
DESIGN:
A retrospective analysis of the Extended Prevalence of Infection in the ICU Study (EPIC II). Demographic, physiological, infection-related and therapeutic data were collected. Patients were grouped as having Candida, Gram-positive, Gram-negative, and combined Candida/bacterial bloodstream infection. Outcome data were assessed at intensive care unit and hospital discharge.
SETTING:
EPIC II included 1265 intensive care units in 76 countries.
PATIENTS:
Patients in participating intensive care units on study day.
INTERVENTIONS:
None.
MEASUREMENT AND MAIN RESULTS:
Of the 14,414 patients in EPIC II, 99 patients had Candida bloodstream infections for a prevalence of 6.9 per 1000 patients. Sixty-one patients had candidemia alone and 38 patients had combined bloodstream infections. Candida albicans (n = 70) was the predominant species. Primary therapy included monotherapy with fluconazole (n = 39), caspofungin (n = 16), and a polyene-based product (n = 12). Combination therapy was infrequently used (n = 10). Compared with patients with Gram-positive (n = 420) and Gram-negative (n = 264) bloodstream infections, patients with candidemia were more likely to have solid tumors (p < .05) and appeared to have been in an intensive care unit longer (14 days [range, 5-25 days], 8 days [range, 3-20 days], and 10 days [range, 2-23 days], respectively), but this difference was not statistically significant. Severity of illness and organ dysfunction scores were similar between groups. Patients with Candida bloodstream infections, compared with patients with Gram-positive and Gram-negative bloodstream infections, had the greatest crude intensive care unit mortality rates (42.6%, 25.3%, and 29.1%, respectively) and longer intensive care unit lengths of stay (median [interquartile range]) (33 days [18-44], 20 days [9-43], and 21 days [8-46], respectively); however, these differences were not statistically significant.
CONCLUSION:
Candidemia remains a significant problem in intensive care units patients. In the EPIC II population, Candida albicans was the most common organism and fluconazole remained the predominant antifungal agent used. Candida bloodstream infections are associated with high intensive care unit and hospital mortality rates and resource use