6,678 research outputs found
What Shapes the Quality and Behavior of Government Officials? Institutional Variation in Selection and Retention Methods
In representative democracies, a variety of rules are employed to select and retain public officials to reflect public preferences over policies. We discuss the literature on selection and retention rules for government officials, focusing on low-information offices. First, we overview the historical origins and the scope of the variation in selection and retention rules. Second, we provide conceptual frameworks for assessing the advantages and disadvantages of direct elections and discuss various factors that influence the functioning of elections. Third, we present empirical regularities. We summarize the baseline effects of the institutional variation and their interaction with factors such as media and compensation. Finally, we discuss outstanding questions on theoretical and empirical fronts, and how the digitization of government information and advances in machine learning can open up new avenues for research
Growth of anisotropic gold nanoparticles in photoresponsive fluid for UV sensing and erythema prediction
Aim: To develop a novel plasmonic nanosensing technique to monitor the exposure levels of UV light for sunlight disease prevention. Methods: Anisotropic gold nanoparticles were grown inside a UV photoresponsive fluid, which was previously exposed to UV radiation from different sources. The morphology and optical properties of the obtained nanoparticles were monitored by spectroscopy and microscopy. Results: The morphological and optical properties of the nanoparticles were dependent on the UV dose. The UV exposure levels were accurately correlated to the UV minimal doses to produce erythema to different skin types. Conclusion: This plasmonic nanosensing technique can be employed as novel sunlight-indexing tool for monitoring the dangerous level of skin exposure
Association of the rs3743205 variant of DYX1C1 with dyslexia in Chinese children
<p>Abstract</p> <p><b>Background</b></p> <p>Dyslexia is a learning disability that is characterized by difficulties in the acquisition of reading and spelling skills independent of intelligence, motivation or schooling. Studies of western populations have suggested that <it>DYX1C1 </it>is a candidate gene for dyslexia. In view of the different languages used in Caucasian and Chinese populations, it is therefore worthwhile to investigate whether there is an association of <it>DYX1C1 </it>in Chinese children with dyslexia.</p> <p>Method and Results</p> <p>Eight single nucleotide polymorphisms (SNPs) were genotyped from three hundred and ninety three individuals from 131 Chinese families with two which have been reported in the literature and six tag SNPs at <it>DYX1C1</it>. Analysis for allelic and haplotypic associations was performed with the UNPHASED program and multiple testing was corrected using false discovery rates. We replicated the previously reported association of rs3743205 in Chinese children with dyslexia (<it>p</it><sub><it>corrected </it></sub>= 0.0072). This SNP was also associated with rapid naming, phonological memory and orthographic skills in quantitative trait analysis.</p> <p>Conclusion</p> <p>Our findings suggest that <it>DYX1C1 </it>is associated with dyslexia in people of Chinese ethnicity in Hong Kong.</p
ELASTOGRAPHY CAN EFFECTIVELY DECREASE THE NUMBER OF FINE-NEEDLE ASPIRATION BIOPSIES IN PATIENTS WITH CALCIFIED THYROID NODULES
When calcification, frequently found in both benign and malignant nodules, is present in thyroid nodules, non-invasive differentiation with ultrasound becomes challenging. The goal of this study was to evaluate the utility of elastography in differentiating calcified thyroid nodules. Consecutive patients (165 patients with 196 nodules) referred for fine-needle aspiration who had undergone both ultrasound elastography and B-mode examinations were analyzed retrospectively. Calcification was present in 45 benign and 20 malignant nodules. On 65 calcified nodules, elastography had 95% sensitivity, 51.1% specificity, 46.3% positive predictive value and 95.8% negative predictive value in detecting malignancy. Twenty-three of 45 benign calcified nodules were correctly diagnosed with elastography compared with 4 of 45 by B-mode ultrasound. Although it is difficult to differentiate benign and malignant calcified thyroid nodules solely with B-mode ultrasound, elastography has the potential to reduce the number of fine-needle aspiration biopsies performed on calcified nodules. (C) 2014 World Federation for Ultrasound in Medicine & Biology.1188Ysciescopu
An artifacts removal post-processing for epiphyseal region-of-interest (EROI) localization in automated bone age assessment (BAA)
<p>Abstract</p> <p>Background</p> <p>Segmentation is the most crucial part in the computer-aided bone age assessment. A well-known type of segmentation performed in the system is adaptive segmentation. While providing better result than global thresholding method, the adaptive segmentation produces a lot of unwanted noise that could affect the latter process of epiphysis extraction.</p> <p>Methods</p> <p>A proposed method with anisotropic diffusion as pre-processing and a novel Bounded Area Elimination (BAE) post-processing algorithm to improve the algorithm of ossification site localization technique are designed with the intent of improving the adaptive segmentation result and the region-of interest (ROI) localization accuracy.</p> <p>Results</p> <p>The results are then evaluated by quantitative analysis and qualitative analysis using texture feature evaluation. The result indicates that the image homogeneity after anisotropic diffusion has improved averagely on each age group for 17.59%. Results of experiments showed that the smoothness has been improved averagely 35% after BAE algorithm and the improvement of ROI localization has improved for averagely 8.19%. The MSSIM has improved averagely 10.49% after performing the BAE algorithm on the adaptive segmented hand radiograph.</p> <p>Conclusions</p> <p>The result indicated that hand radiographs which have undergone anisotropic diffusion have greatly reduced the noise in the segmented image and the result as well indicated that the BAE algorithm proposed is capable of removing the artifacts generated in adaptive segmentation.</p
Clinical Significance of Physical Frailty in Subjects With Subjective Cognitive Decline: A Prospective Study With Amyloid PET Data
Background and Purpose: Physical frailty is known to be closely associated with cognitive impairment and to be an early sign of Alzheimer’s disease. We aimed to understand the characteristics of physical frailty and define factors associated with physical frailty in subjects with subjective cognitive decline (SCD) by analyzing amyloid data. Methods We prospectively enrolled subjects with SCD from a cohort study to identify predictors for the clinical progression to mild cognitive impairment or dementia from SCD (CoS-Co). All of the subjects underwent brain magnetic resonance imaging, and brain amyloid positron-emission tomography (PET) to detect amyloid beta plaques. Self-reported exhaustion, handgrip strength, and gait speed were used to measure physical frailty. Results Of 120 subjects with SCD, 26 (21.7%) were amyloid-positive in PET. Female (odds ratio [OR]=3.79, p=0.002) and amyloid-PET-positive (OR=3.80, p=0.008) subjects with SCD were at high risks of self-reported exhaustion. Amyloid PET positivity (OR=3.22, p=0.047) and high burden from periventricular white-matter hyperintensity (OR=3.34, 95% confidence interval=1.18–9.46, p=0.023) were significantly associated with a weaker handgrip. The subjects with SCD with self-reported exhaustion and weaker handgrip presented with lower cognitive performance in neuropsychological tests, especially for information processing speed and executive function. Subjects with a slower gait performed worse in visual memory function tests. Conclusions Amyloid PET positivity was associated with a higher risk of self-reported exhaustion and weaker handgrip in subjects with SCD. The subjects with SCD and physical frailty also performed worse in neuropsychological tests
Severity of Nonalcoholic Fatty Liver Disease is Associated with Development of Metabolic Syndrome: Results of a 5-Year Cohort Study
Aims: Nonalcoholic fatty liver disease (NAFLD) is considered to be a hepatic manifestation of metabolic syndrome (MS).
However, a few studies have examined the effect of NAFLD on the development of MS. We evaluated the relationship
between the development of MS and clinical severity of NAFLD according to alanine aminotransferase (ALT) levels.
Methods: A retrospective cohort study was conducted. Participants who underwent abdominal ultrasonography and blood
samplings for health check-ups both in 2005 and 2010 were recruited. NAFLD was diagnosed if a person showed fatty liver
on ultrasonography without significant alcohol consumption. Subjects with MS at baseline were excluded.
Results: A total of 2,728 subjects met the inclusion criteria. Fatty liver (FL) with normal ALT was found in 369 (13.5%)
subjects and FL with elevated ALT in 328 (12.0%). During 5 years of follow up, 582 (21.3%) incident cases of MS developed
between 2005 and 2010. The incidence of MS was higher in patients with NAFLD compared to control group (41.2%
in FL with elevated ALT, 34.7% in FL with normal ALT and 15.7% in control, p<0.001). Multivariate analysis showed that
odds ratio (OR) and 95% confidence interval (CI) for MS increased according to the severity of NAFLD [OR (95% CI),
1.29 (0.97−1.71) in FL with normal ALT and 1.54 (1.18−1.33) in FL with elevated ALT, p=0.01].
Conclusions: We have demonstrated that development of MS is significantly increased according to the clinical severity of
NAFLD. These findings have implications in the clinical availability of NAFLD as a predictor of MS
Impact of neoadjuvant treatment on total mesorectal excision for ultra-low rectal cancers
<p>Abstract</p> <p>Background</p> <p>This study reviewed the impact of pre-operative chemoradiotherapy or post-operative chemotherapy and/or radiotherapy on total mesorectal excision (TME) for ultralow rectal cancers that required either low anterior resection with peranal coloanal anastomosis or abdomino-perineal resection (APR). We examined surgical complications, local recurrence and survival.</p> <p>Methods</p> <p>Of the 1270 patients who underwent radical resection for rectal cancer from 1994 till 2007, 180 with tumors within 4 cm with either peranal coloanal anastomosis or APR were analyzed. Patients were compared in groups that had surgery only (Group A), pre-operative chemoradiotherapy (Group B), and post-operative therapy (Group C).</p> <p>Results</p> <p>There were 115 males and the mean age was 65.43 years (range 30-89). APR was performed in 134 patients while 46 had a sphincter-preserving resection with peranal coloanal anastomosis. The mean follow-up period was 52.98 months (range: 0.57 to 178.9). There were 69, 58 and 53 patients in Groups A, B, and C, respectively. Nine patients in Group B could go on to have sphincter-saving rectal resection. The overall peri-operative complication rate was 43.4% in Group A vs. 29.3% in Group B vs. 39.6% in Group C, respectively. The local recurrence rate was significantly lower in Group B (8.6.9% vs. 21.7% in Group A vs. 33.9% in Group C) <it>p < 0.05</it>. The 5-year cancer-specific survival rates for Group A was 49.3%, Group B was 69.9% and Group C was 38.8% (<it>p </it>= 0.14).</p> <p>Conclusion</p> <p>Pre-operative chemoradiation in low rectal cancer is not associated with a higher incidence of peri-operative complications and its benefits may include reduction local recurrence.</p
Simulation of the deflected cutting tool trajectory in complex surface milling
Since industry is rapidly developing, either locally
or globally, manufacturers witness harder challenges due to
the growing competitivity. This urges them to better consider the four factors linked to production and output: quality, quantity, cost and price, quality being of course the most important factor which constitutes their main concern. Efforts will be concentrated—in this research—on improving the quality and securing more accuracy for a machined surface in ball-end milling. Quality and precision are two essential criteria in industrial milling. However, milling errors and imperfections, duemainly to the cutting tool deflection, hinder the full achieving of these targets. Our task, all along this paper, consists in studying and realizing the simulation of the deflected cutting tool trajectory, by using the methods which are available. In a future stage, and in the frame of a deeper
research, the simulation process will help to carry out the
correction and the compensation of the errors resulting from
the tool deflection. The corrected trajectory which is obtained by the method mirror will be sent to the machine. To achieve this goal, the next process consists—as a first step—in selecting a model of cutting forces for a ball-end mill. This allows to define—later on—the behavior of this tool, and the emergence of three methods namely the analytical model, the finite elements method, and the experimental method. It is possible to tackle the cutting forces simulation, all along the tool trajectory, while this latter is carrying out the sweeping of the part to be machined in milling and taking into consideration the cutting conditions, as well as the geography of the workpiece. A simulation of the deflected cutting tool trajectory dependent on the cutting forces has been realized
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