Visual Imagery and Perception Share Neural Representations in the Alpha Frequency Band

To behave adaptively with sufficient flexibility, biological organisms must cognize beyond immediate reaction to a physically present stimulus. For this, humans use visual mental imagery [1, 2], the ability to conjure up a vivid internal experience from memory that stands in for the percept of the stimulus. Visually imagined contents subjectively mimic perceived contents, suggesting that imagery and perception share common neural mechanisms. Using multivariate pattern analysis on human electroencephalography (EEG) data, we compared the oscillatory time courses of mental imagery and perception of objects. We found that representations shared between imagery and perception emerged specifically in the alpha frequency band. These representations were present in posterior, but not anterior, electrodes, suggesting an origin in parieto-occipital cortex. Comparison of the shared representations to computational models using representational similarity analysis revealed a relationship to later layers of deep neural networks trained on object representations, but not auditory or semantic models, suggesting representations of complex visual features as the basis of commonality. Together, our results identify and characterize alpha oscillations as a cortical signature of representations shared between visual mental imagery and perception

Karar Ağacı Algoritması Kullanılarak Çin Topraklarındaki Orta Dereceli Okul Öğrencilerine İlişkin Jeo-Uzamsal Düşünme Yeteneğinin Tahmin Edilmesi

Predicting secondary school students' geospatial thinking ability can provide targeted guidance for teachers. To date, few scholars have focused on predicting students’ geospatial thinking ability. In this paper, we address this gap by constructing a prediction model based on the decision tree algorithm, to predict the geospatial thinking ability of secondary school students. A total of 1029 secondary school students were surveyed using the Spatial Thinking Ability Test, the Students' Geography Learning Status Questionnaire, and the Middle Students Motivation Test. Our model indicates that geospatial thinking ability can be predicted by nine factors, in order of importance: academic achievement in geography, geography learning strategy, geography classroom environment, gender, learning initiative, learning goals, extra-curricular time spent learning geography, ego-enhancement drive, and interest in learning geography. The model accuracy is 81.25%. Specifically, our study is the first to predict geospatial thinking ability. It provides a tool for teachers that can help them identify and predict students' geospatial thinking ability, which is conducive to designing better teaching plans and making adjustments to the curriculum.Orta dereceli okul öğrencilerinin jeo-uzamsal düşünme yeteneklerinin tahmin edilmesi öğretmenler için hedefe yönelik rehberlik sağlayabilir. Şimdiye kadar az sayıda bilim insanı, öğrencilerin jeo-uzamsal düşünme yeteneklerinin tahmin edilmesine odaklanmıştır. Bu makalede, orta dereceli okul öğrencilerinin jeo-uzamsal düşünme yeteneklerinin tahmin edilmesi amacıyla karar ağacı algoritmasına dayanan bir tahmin modeli oluşturarak bu boşluğu doldurmayı amaçlıyoruz. Uzamsal Düşünme Yeteneği Testi, Öğrencilerin Coğrafya Öğrenimi Durumu Anketi ve Orta Dereceli Okul Öğrencileri Motivasyon Testi kullanılarak toplam 1029 orta dereceli okul öğrencisine anket uygulanmıştır. Modelimiz, jeo-uzamsal düşünme yeteneğinin dokuz etmenle tahmin edilebileceğine işaret etmektedir. Önem sırasına göre bu etmenler; coğrafya dersindeki akademik başarı, coğrafya öğrenimi stratejisi, coğrafya sınıf ortamı, cinsiyet, öğrenme inisiyatifi, öğrenme hedefleri, coğrafya öğreniminde harcanan müfredat harici zaman, benlik geliştirme dürtüsü ve coğrafya öğrenimine ilgi şeklindedir. Model doğruluk oranı %81,25’tir. Özellikle, çalışmamız jeo-uzamsal düşünme yeteneğinin tahmin edilmesine yönelik ilk çalışmadır. Öğretmenlere öğrencilerin jeo-uzamsal düşünme yeteneklerini saptamalarına ve tahmin etmelerine yardımcı olabilecek bir araç sunan çalışmamız böylelikle daha iyi eğitim planları hazırlanmasında ve müfredatta düzenlemeler yapılmasında fayda sağlayacaktır

Evaluation of Tung Oil (Vernicia fordii (Hemsl.)) for Controlling Termites

In worldwide, the use of chemical pesticides to protect wood has been greatly restricted. In recent years, a large number of researchers devoted to the search for natural, safe and non-polluting bioactive chemical compounds from plants as an alternative to synthetic organic chemical preservative. In Chinese folk, tung oil can be used as paint for wooden furniture to protect them from pests. This study aimed to evaluate the chemical compositions of raw and heated tung oil and their activity against termite. In choice bioassays, weight loss of wood treated with 5% raw or heated tung oil after 4 weeks was significantly less than that of the control group. In no-choice bioassays, there was a significant difference in termite survival and wood weight loss on raw and heated tung oil-treated wood. When tung oil-treatment concentrations increased to 5%, wood weight loss was less than 10%. There was no significant difference in termite survival and wood weight loss between raw and heated tung oil-treated wood. Survival of termites in both tung oil wood treatments was significantly lower than that in the starvation control after 4 weeks. Raw and heated tung oil significantly improved the resistance of pine wood to termites, and have the potential for the development of natural wood preservatives

Herb-Drug Interaction: Effects of Relinqing® Granule on the Pharmacokinetics of Ciprofloxacin, Sulfamethoxazole, and Trimethoprim in Rats

Relinqing granule (RLQ) is the best-selling Chinese patent drug for treatment of urinary system diseases. In this study, the effects of RLQ on the pharmacokinetics of ciprofloxacin, sulfamethoxazole, and trimethoprim in SD rats were investigated. Rats were randomly divided into control group 1, control group 2, RLQ group 1, and RLQ group 2. RLQ group 1 and RLQ group 2 were treated orally with RLQ for 7 days, and rats were treated with the same volume of water in control group 1 and control group 2. Then, RLQ group 1 and control group 1 were given intragastrically ciprofloxacin on day 8, while RLQ group 2 and control group 2 were given intragastrically sulfamethoxazole and trimethoprim on day 8. Blood samples were collected and determined. There was no significant influence of pharmacokinetic parameters of trimethoprim on two groups. But some pharmacokinetic parameters of ciprofloxacin and sulfamethoxazole in RLQ pretreated rats were evidently altered (P < 0.05), which indicated that absorption of ciprofloxacin and sulfamethoxazole in RLQ pretreated rats was significantly affected. It indicated the coadministration of RLQ would have an influence on the efficacy of ciprofloxacin and sulfamethoxazole, and the doses of ciprofloxacin tablet and compound sulfamethoxazole tablet need adjustment

Avoided Crossing Patterns and Spectral Gaps of Surface Plasmon Modes in Gold Nano-Structures

The transmission of ultrashort (7 fs) broadband laser pulses through periodic gold nano-structures is studied. The distribution of the transmitted light intensity over wavelength and angle shows an efficient coupling of the incident p-polarized light to two counter-propagating surface plasmon (SP) modes. As a result of the mode interaction, the avoided crossing patterns exhibit energy and momentum gaps, which depend on the configuration of the nano-structure and the wavelength. Variations of the widths of the SP resonances and an abrupt change of the mode interaction in the vicinity of the avoided crossing region are observed. These features are explained by the model of two coupled modes and a coupling change due to switching from the high frequency dark mode to the low frequency bright mode for increasing wavelength of the excitation light. PACS numbers: 73.20.Mf, 42.70.Qs, 42.25.-p,Comment: 17 pages, 4 figure

Ticagrelor vs Clopidogrel in CYP2C19 loss-of-function carriers with Stroke or TIA

BACKGROUNDComparisons between ticagrelor- aspirin and clopidogrel-aspirin in CYP2C19 loss-of-function carriers have not been well studied for secondary stroke prevention.METHODSWe conducted a randomized, double-blind, placebo-controlled trial of 6,412 patients with a minor ischemic stroke or TIA who carried CYP2C19 LOF alleles determined by point-of-care testing. Patients were randomly assigned within 24 hours after symptom onset, in a 1:1 ratio to receive ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2 through 90) or clopidogrel (300 mg loading dose on day 1 followed by 75 mg per day for days 2 through 90), plus aspirin (75-300 mg loading dose followed by 75 mg daily for 21 days). The primary efficacy outcome was stroke and the primary safety outcome was severe or moderate bleeding, both within 90 days. RESULTSStroke occurred within 90 days in 191 (6.0%) versus 243 (7.6%), respectively (hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.94; P=0.008). Moderate or severe bleeding occurred in 9 patients (0.3%) in the ticagrelor-aspirin group and in 11 patients (0.3%) in the clopidogrel-aspirin group; any bleeding event occurred in 170 patients (5.3%) vs 80 (2.5%), respectively. CONCLUSIONSAmong Chinese patients with minor ischemic stroke or TIA within 24 hours after symptoms onset who were carriers of CYP2C19 loss-of-function alleles, ticagrelor- aspirin was modestly better than clopidogrel-aspirin for reducing the risk of stroke but was associated with more total bleeding events at 90 days. (CHANCE-2 ClinicalTrials.gov number, NCT04078737.

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Demodulating of the 3-D tip clearance of turbine blades using BP neural network optimized by genetic algorithm

International audienceThe traditional tip clearance of aero-engine is a one-dimensional variable signal, which contains poor fault information of turbine blades. In contrast, the three-dimensional (3-D) tip clearance of the aero-engine contains more abundant fault information, which can reflect the fault features of turbine blades more intuitively and comprehensively. The typical faults of turbine blades such as thermal fatigue and crack can be diagnosed based on three-dimensional tip clearance. Therefore, an optical fiber probe with three two–circle coaxial bundles based on intensity modulation is used to obtain three-dimensional tip clearance. The voltage signal collected by a single unit of the optical fiber probe is modulated simultaneously by the distance and the inclination angle between the probe end face and the measured surface, therefore it is difficult to demodulate three-dimensional tip clearance from output signal of the optical fiber probe. In this paper, an approach for demodulating of three-dimensional tip clearance of turbine blades is presented using BP neural network optimized by genetic algorithm. Three voltage ratios and three-dimensional tip clearance are used as input and output of BP neural network, respectively. Optimizing the weights and thresholds of BP neural network by genetic algorithm makes the prediction output of BP neural network more accurate.The high dimensional and nonlinearity problem between the optical probe output voltage signal and three-dimensional tip clearance can be solved by this approach. The training and test data is obtained through static calibration bench such as Fig.1 and the data is preprocessed to ensure its reliability and accuracy. Experiment results show that this demodulating approach has good precision, which can fulfil the requirements of three-dimensional tip clearance detection and provides a powerful guarantee for the fault diagnosis of turbine blades

Research on the Variation Mechanism of the 3-D Tip Clearance of a Cracked Blade under Multi-parameters in the Aero-engine Acceleration Process

International audienceThe 3-D tip clearance has some advantages over the traditional radial tip clearance in the fault diagnosis of the turbine blade crack. The research on the variation mechanism of the 3-D tip cle arance is of great significance, but previous researches only focused on the steady state condition of the aero-engine, lacking consideration s of the aero-engine acceleration process. In this study, a numerical model of high pressure turbine blisk was established, and t he centrifugal load, thermal load and aerodyn amic load of the aero-engine, varying with time, were considered in this model. Besides, the cracks with different length and location were added to the trailing edge of the blade, and the 3-D tip clearance of cracked blades was calculated. The results show that there are some obvious distinctions in the 3-D tip clearance between a normal blade and cracked blades, which can reflect blade crack informa tion accurately and effectively. The results also indicate that the 3-D tip clearance is promising in fault diagnosis of the turbine blade crack