601 research outputs found

    Extreme coefficients in Geographically Weighted Regression and their effects on mapping

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    This study deals with the issue of extreme coefficients in geographically weighted regression (GWR) and their effects on mapping coefficients using three datasets with different spatial resolutions. We found that although GWR yields extreme coefficients regardless of the resolution of the dataset or types of kernel function, 1) the GWR tends to generate extreme coefficients for less spatially dense datasets, 2) coefficient maps based on polygon data representing aggregated areal units are more sensitive to extreme coefficients, and 3) coefficient maps using bandwidths generated by a fixed calibration procedure are more vulnerable to the extreme coefficients than adaptive calibration.extreme coefficient, fixed and adaptive calibrations, geographically weighted regression, Mapping, Research Methods/ Statistical Methods,

    An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding

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    The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators

    Ecotoxicity of heat-treated Kapur and Japanese larch

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    Kapur (Dryobalanops sp.) and Japanese larch (Larix kaempferi) wood samples were heat-treated in air at 180 °C for 24 and 48 h. Leaching and toxicity tests were conducted to determine the ecotoxicity effect of these heat-treated woods on the aquatic environment due to heat treatment. The toxicity of conventional preservative-treated woods, i.e. chromated copper arsenate (CCA) and ammoniacal copper quat (ACQ), was also determined for comparison purposes. Acute toxicity tests were performed using two aquatic organisms, Daphnia magna and Vibrio fischeri according to the Organization for Economic Co-operation and Development standard procedures and Microtox assay, respectively. Significantly low toxicity to D. magna was found for the heat-treated Kapur compared to that of untreated Kapur, while heat-treated Japanese larch did not show any toxicity effect. As expected, ACQ-treated samples showed the highest toxicity to D. magna, followed by that of CCA, though toxicity of both preservative-treated woods further reduced over time. Hence, heat treatment of Kapur and Japanese larch were believed to be not harmful to the aquatic ecosystem

    Patterned Si thin film electrodes for enhancing structural stability

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    A patterned film (electrode) with lozenge-shaped Si tiles could be successfully fabricated by masking with an expanded metal foil during film deposition. Its electrochemical properties and structural stability during the charge-discharge process were examined and compared with those of a continuous (conventional) film electrode. The patterned electrode exhibited a remarkably improved cycleability (75% capacity retention after 120 cycles) and an enhanced structural stability compared to the continuous electrode. The good electrochemical performance of the patterned electrode was attributed to the space between Si tiles that acted as a buffer against the volume change of the Si electrode

    Major medical causes by breed and life stage for dogs presented at veterinary clinics in the Republic of Korea: a survey of electronic medical records

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    Background Age and breed are considered the greatest risk factors for disease prevalence and mortality in companion dogs. Understanding the prevalence of diseases, in relation to age and breed, would support appropriate guidance for future health care strategies and provide useful information for the early diagnosis of diseases. The purpose of this study was to investigate the major medical causes for dogs visiting primary-care veterinary clinics in the Republic of Korea, stratified by age and breed. Methods A total of 15,531 medical records of canine patients were analyzed from 11 veterinary clinics who shared data from January 1, 2016 to December 31, 2016. An electronic medical record (EMR) system was used for data collection, which included the animal identification number, age, breed, gender, neuter status, clinical information, and diagnosis. EMR data were classified using the International Classification of Disease system from the World Health Organization; presenting signs or diagnoses were identified according to breed and life stage. Results Within the age groups, preventive medicine (16.7% confidence intervals (CI) [15.9–17.5]) was the most common cause for clinic visits for the 10 year), the prevalences of heart disease, kidney disease, Cushing’s disease, and mammary tumors were higher than in the other age groups. Small and toy breed dogs comprised 67.7% of all dogs in this analysis. For all breeds, otitis externa, dermatitis or eczema, vomiting, and diarrhea were common medical problems. Discussion This study identified the most common medical disorders and differences in prevalences of diseases, according to age and breeds. The information from EMRs for dogs visiting primary-care veterinary clinics can provide background knowledge that is required to enable a better understanding of disease patterns and occurrence by age and breeds. The information from this study could enable the creation of strategies for preventing diseases and enable the identification of health problems for more effective disease management in companion dogs

    Absorbable Plate as a Perpendicular Strut for Acute Saddle Nose Deformities

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    BackgroundNasal pyramid fractures accompanied by saddle nose deformities are not easily corrected by closed reduction. We used an absorbable plate as a perpendicular strut to support the collapsed "keystone area" and obtained good results.MethodsBetween September 2008 and June 2011, 18 patients who had nasal pyramid fractures with saddle nose deformities underwent surgery. Pre- and postoperative facial computed tomographic images and photographs were taken to estimate outcomes. The operative technique included the mucoperichondrial dissection of the nasal septum, insertion of an absorbable plate prepared to an appropriate length to support the "keystone area", and fixation of the absorbable plate strut to the cartilaginous septum.ResultsFunctional and esthetic outcomes were satisfactory in all patients. Eleven patients assessed the postoperative appearance of the external nose as 'markedly improved' and 7 patients as 'improved'. The 5 surgeons scored the results as a mean of 4.5 on a 5-point scale.ConclusionsThe use of an absorbable plate as a perpendicular strut requires no additional procedures because the plate is gradually absorbed. The mechanical strength provided by a buttress between the "keystone area" and the maxillary crest lasts for a long time before the strut is absorbed
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