1,150 research outputs found
Recommendation: A Less Explored Killer-App of Uncertainty?
Due to the unprecedented amount of information available, it is becoming
more and more important to provide personalized recommendations on data, based on past user feedbacks. However, available user feedbacks or ratings are extremely sparse, which motivates the needs for rating prediction. The most widely adopted solution has been collaborative filtering, which (1) identifies "neighboring" users with similar tastes and (2) aggregates their ratings to predict the ratings of the given user. However, while each of such aggregation involves varying levels of uncertainty, e.g., depending on the distribution of ratings aggregated, which has not been systematically considered in recommendation, though recent study suggests such consideration can boost prediction accuracy. To consider uncertainty in rating prediction, this paper reformulates the collaborative filtering problem as aggregating community ratings into multiple predicted ratings with varying levels of certainty, based on which we identify top-k results with both high confidence and rating. We empirically study the efficiency and accuracy of our proposed framework, over a classical collaborative filtering system
Surgical experience of pericardial mesothelioma presenting as constrictive pericarditis
SummaryWe report two cases, which had been initially diagnosed with constrictive pericarditis but later were definitely diagnosed with mesothelioma after receiving pericardiectomy. The two patients complained of dyspnea. Chest computed tomography showed mild pericardial effusion and thickened pericardium, which was found enveloping the heart without any lumps. Pericardiectomy (phrenic nerve to phrenic nerve) was performed and post-operative histology confirmed malignant mesothelioma. One patient had recurrence near the pericardium at 7 months post-operatively and died at 11 months post-operatively. Another patient, after receiving chemotherapy, is still alive at 16 months post-operatively. We consider that pericardial mesothelioma, an extremely rare disease exhibiting clinical signs similar to those of constrictive pericarditis, must be diagnosed at the early stage of its onset
Spontaneous Pharyngeal Perforation After Forceful Vomiting: The Difference from Classic Boerhaave's Syndrome
Boerhaave's syndrome is spontaneous transmural perforation of the esophagus, which occurs most often after forceful vomiting or retching. This commonly occurs in the lower third of the esophagus but spontaneous perforation of the pharynx or cervical esophagus is extremely rare. This case presented a 20-yr-old healthy man with spontaneous pharyngeal perforation after forceful vomiting who had no history of instrumentation, cervical trauma, or having eaten anything sharp. Cervical pain and crepitus were the early symptom and sign of pharyngeal perforation and the rupture was detected on gastrografin swallow and CT examinations. The rupture site was higher than the upper esophageal sphincter, differing from Boerhaave's syndrome. The patient was conservatively managed without significant morbidity and mortality. Although this may resolve without surgical intervention, the pharyngeal rupture should receive early detection and clinical attention for preventing potential morbidity by late diagnosis
High-Performance Screen-Printed Thermoelectric Films on Fabrics.
Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi0.5Sb1.5Te3 or n-type Bi2Te2.7Se0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively
Prevalence of Inducible Clindamycin Resistance in Staphylococcal Isolates at a Korean Tertiary Care Hospital
Clindamycin resistance in Staphylococcus species can be either constitutive or inducible. Inducible resistance cannot be detected by the conventional antimicrobial susceptibility test. In this study, we determined the prevalence of inducible clindamycin resistance in staphylococcal isolates at a Korean tertiary care hospital. Between February and September 2004, 1,519 isolates of Staphylococcus aureus and 1,043 isolates of coagulase-negative staphylococci (CNS) were tested for inducible resistance by the D-zone test. Overall, 17% of MRSA, 84% of MSSA, 37% of MRCNS, and 70% of MSCNS were susceptible to clindamycin. Of the erythromycin non-susceptible, clindamycin-susceptible isolates, 32% of MRSA, 35% of MSSA, 90% of MRCNS, and 94% of MSCNS had inducible clindamycin resistance. Inducible clindamycin resistance in staphylococci was highly prevalent in Korea. This study indicates importance of the D-zone test in detecting inducible clindamycin resistance in staphylococci to aid in the optimal treatment of patients
Prediction Forecast for Culex tritaeniorhynchus Populations in Korea
AbstractObjectivesJapanese encephalitis is considered as a secondary legal infectious disease in Korea and is transmitted by mosquitoes in the summer season. The purpose of this study was to predict the ratio of Culex tritaeniorhynchus to all the species of mosquitoes present in the study regions.MethodsFrom 1999 to 2012, black light traps were installed in 10 regions in Korea (Busan, Gyeonggi, Gangwon, Chungbuk, Chungnam, Jeonbuk, Jeonnam, Gyeongbuk, Gyeongnam, and Jeju) to capture mosquitoes for identification and classification under a dissecting microscope. The number of mosquitoes captured/week was used to calculate its daily occurrence (mosquitoes/trap/night). To predict the characteristics of the mosquito population, an autoregressive model of order p (AR(p)) was used to execute the out-of-sample prediction and the in-sample estimation after presumption.ResultsCompared with the out-of-sample method, the sample-weighted regression method's case was relatively superior for prediction, and this method predicted a decrease in the frequency of Cx. tritaeniorhynchus for 2013. However, the actual frequency of this species showed an increase in frequency. By contrast, the frequency rate of all the mosquitoes including Cx. tritaeniorhynchus gradually decreased.ConclusionThe number of patients with Japanese encephalitis has been strongly associated with the occurrence and density of vector mosquitoes, and the importance of this infectious disease has been highlighted since 2010. The 2013 prediction indicated an increase after an initial decrease, although the ratio of the two mosquito species decreased. The increase in vector density may be due to changes in temperature and the environment. Thus, continuous prevalence prediction is warranted
Evaluation on antioxidant properties of sixteen plant species from Jeju Island in Korea
In this study, the antioxidant properties of 80 % ethanol extracts of 16 species of plants from Jeju Island in Korea were evaluated using various antioxidant assays, including the DPPH (1,1-Diphenyl-2-pricrylhydrazyl) radical scavenging, superoxide scavenging, xanthine oxidase inhibition and hydrogen peroxide scavenging activities. Among the 16 plant extracts tested, CN-13 showed strong antioxidant properties in the DPPH radical scavenging and hydrogen peroxide scavenging tests. The CN-13 ethanol extract was thus selected to be used for further experiments, and was separated into various fractions using four different organic solvents (n-hexane, methylene chloride, ethyl acetate and butanol). The ethyl acetate fraction of CN-13 extract evidenced strong DPPH radical scavenging properties as compared to the other fractions. The ethyl acetate fraction also strongly inhibited DNA-damage induced by hydrogen peroxide-oxidative damage in a mouse lymphoma (L5178Y-R) cell line. Moreover, a correlation between the total phenolic content of the extract, and its antioxidant property was reported
The Response of CMS Combined Calorimeters to Single Hadrons, Electrons and Muons
We report on the response of the combined CMS electromagnetic (EB) and hadronic barrel (HB) calorimeters to hadrons, electrons and muons in a wide momentum range from 1 to 350 GeV/c. To our knowledge, this is the widest range of momenta in which any calorimeter system is studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. We analyze in detail the differences in total calorimeter response to charged pions, kaons, protons and antiprotons and discuss the underlying phenomena. These data will play a crucial role in the thorough understanding of jets in CMS
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