179 research outputs found

    Suspect identification based on descriptive facial attributes

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    We present a method for using human describable face attributes to perform face identification in criminal inves-tigations. To enable this approach, a set of 46 facial at-tributes were carefully defined with the goal of capturing all describable and persistent facial features. Using crowd sourced labor, a large corpus of face images were manually annotated with the proposed attributes. In turn, we train an automated attribute extraction algorithm to encode target repositories with the attribute information. Attribute extrac-tion is performed using localized face components to im-prove the extraction accuracy. Experiments are conducted to compare the use of attribute feature information, derived from crowd workers, to face sketch information, drawn by expert artists. In addition to removing the dependence on expert artists, the proposed method complements sketch-based face recognition by allowing investigators to imme-diately search face repositories without the time delay that is incurred due to sketch generation. 1

    Detection and localization of emitters in the presence of multipath

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    Yön bulma işlemi kısaca DF (Direction Finding, Yön Bulma) veya AOA (Angle of Arrival, Geliş Açısı) olarak ifade edilmektedir. Antenler, alıcı, sayısal kart ve bilgisayardan oluşan sisteme de DF (Direction Finding, Yön Bulma) sistemi denmektedir. DF sistemi tek olarak sadece vericilerin yönünü tespit edebilmektedir. Eğer amaç vericilerinin konumunun belirlenmesi ise ortamda en az iki DF sistemi bulunması gerekmektedir. Bu çalışmada telsiz vericilerinin sayılarının ve yerlerinin tespiti için yeni bir yöntem önerilmiştir. Telsiz vericilerinin sayısının ve yerinin tespitinde MDL (Minimum Description Length, Minimum Tanımlama Uzunluğu) tabanlı ITC (Information Theoretic Criteria) algoritması ile önce ortamdaki yol sayısının daha sonra MUSIC (Multiple Signal Classification, Çoklu İşaret Sınıflandırma) algoritması ile vericilerin yönlerinin belirlenmesi önemli bir aşamadır. MUSIC spektrumundaki her bir tepe her bir yolun geliş açısına karşılık gelecektir. Fakat çoklu yansımalı ortamlarda bir vericiden birden fazla yoldan işaret yayılacağından DF için ek çalışmalar gerekecektir. MVBF (Minimum Variance Beamforming, Minimum Varyans Huzme Şekillendirme) huzme şekillendirme algoritması kullanılarak her yoldan gelen işaretlerin zaman ekseni verileri elde edilir ve aralarındaki korelasyon katsayıları hesaplanır. Bu korelasyon katsayıları kullanılarak işaretlerin aynı kaynaktan yayılıp yayılmadıklarına karar verilir. Böylece verici sayısı ve onların yönleri tespit edilmektedir. Performans analizleri gerçek zamanlı deneylerle elde edilerek sunulmaktadır. Önerilen tekniğin etkinlik testi, tam yansımasız oda içerisinde iki kaynaklı denemelerle gerçekleştirilmiştir. Dış ortamda da başarılı denemeler yapılmıştır.  Anahtar Kelimeler: DF, dizilim anten, huzme şekillendirme, yön tespit.Direction Finding (DF), or in other words, estimation of Angle of Arrival (AOA), has been an active research area since the beginning of the 20th century. DF has several application areas such as, military applications, GSM with improved channel capacity, localization of illegal transmitters such as TV and radio stations, or, of a mountaineer losing his/her path, in addition to spectrum monitoring.When multiple sources are incident on an antenna array simultaneously, classical DF methods, such as interferometry and Doppler cannot resolve these sources. An effective solution to the problem is to use high-resolution subspace-based algorithms. Multiple Signal Identification and Classification (MUSIC) is the most powerful and widely used subspace-based method. MUSIC is known to successfully resolve two or more sources if they are incoherent. However, in practice, signals often propagate in multipath environments. Thus, a source signal is incident on the array from many paths, which implies that coherent signals at different angles will be received by an array.For source localization with MUSIC in a multipath environment, it is critical to initially detect the number of incident paths. The simplest such algorithms are based on counting the smallest eigenvalues of the array covariance matrix. Information Theoretic Criteria (ITC) is advanced algorithm for path enumeration widely used, such as the Akaike Informatin Criteria (AIC) and Minimum Description Length (MDL). Just as in MUSIC, these ITC algorithms are also affected in a multipath environment. This is due to the fact that signal coherence in a multipath environment alters the eigenstructure of the sensor array's correlation matrix, which in turn affects the performance of both MUSIC and ITC. MDL was proposed for source enumeration in the presence of multipath and signal coherence. A recent solution proposed for the problem of signal coherence is the Spatial Smoothing (SS) preprocessing algorithm. SS essentially removes the effect of coherency between incoming signals in the eigen-structure of the correlation matrix. Therefore, source localization process involves the following steps: First, the array antenna output is processed to form a sample covariance matrix, then SS is applied to this matrix, after which the number of signals are estimated and finally, based on these, MUSIC is used to generate an angle spectrum.It is important to note that in a multipath environ-ment, ITC with spatial smoothing merely detects the number of paths, i.e., the signals originating from sources directly or incident from the reflectors, and then the MUSIC algorithm localizes all these signals in the angle/AOA pseudospectrum. In other words, ITC and/or the MUSIC-AOA pseudospectrum, indicate the number of paths and not the number of independent sources present in a multipath environment. This is a significant problem if the objective is to localize actual independent sources in a multipath environment.In this study, the minimum description length information-theoretic algorithm is used for the joint detection and localization of multiple RF transmitters in a multipath environment is to enumerate the number of paths and then to measure the angle of arrival of each path using an antenna array with a high resolution direction finding algorithm such as MUSIC. Those possible propagation paths are the angles corresponding to the peaks of the MUSIC pseudospectrum. Since more than one path may correspond to a single emitter source, further processing is required. The time domain signals of these paths are then extracted with minimum variance beamforming in order to estimate their corre-lation coefficients with each other. These correlation coefficients are used to decide whether or not these paths correspond to the same emitter. Hence, the number of emitters and their angle of arrivals are jointly estimated. Performance analysis of the method is presented via real-time laboratory experimentation and discussed in this paper. To demonstrate the effectiveness of the proposed technique, experiments with two sources are conducted in an anechoic test chamber.  Keywords: DF, direction finding, array antenna, beamforming, MVBF

    Evaluation of three instrumentation techniques at the precision of apical stop and apical sealing of obturation

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    OBJECTIVE: The aim of this study was to investigate the ability of two NiTi rotary apical preparation techniques used with an electronic apex locator-integrated endodontic motor and a manual technique to create an apical stop at a predetermined level (0.5 mm short of the apical foramen) in teeth with disrupted apical constriction, and to evaluate microleakage following obturation in such prepared teeth. MATERIAL AND METHODS: 85 intact human mandibular permanent incisors with single root canal were accessed and the apical constriction was disrupted using a #25 K-file. The teeth were embedded in alginate and instrumented to #40 using rotary Lightspeed or S-Apex techniques or stainless-steel K-files. Distance between the apical foramen and the created apical stop was measured to an accuracy of 0.01 mm. In another set of instrumented teeth, root canals were obturated using gutta-percha and sealer, and leakage was tested at 1 week and 3 months using a fluid filtration device. RESULTS: All techniques performed slightly short of the predetermined level. Closest preparation to the predetermined level was with the manual technique and the farthest was with S-Apex. A significant difference was found between the performances of these two techniques (

    The efficacy of preopoerative instruction in reducing anxiety following gyneoncological surgery: a case control study

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    <p>Abstract</p> <p>Background</p> <p>This is a quasi-experimental case control research focusing on the impact of systematic preoperative instruction on the level of postoperative anxiety in gyneoncologic patients. The population studied consists of the gyneoncologic surgery patients admitted to the Gynecologic Oncology Service at Zekai Tahir Burak Gynecology Training and Research Hospital from May to September 2010.</p> <p>Patients and methods</p> <p>Through a random sampling, 60 patients were recruited in each group. The study group was given a systematic preoperative instruction while the control group was given routine nursing care. Patients were interviewed in the postoperative period and anxiety was measured. The data-collecting tool consisted of the Individual Information Form and the State-Trait Anxiety Inventory. The collected data were analyzed by using the SPSS Program to find the frequency, the percentage, the mean and the standard variables, and the hypothesis was tested with Chi-square, variance, and t-independent test.</p> <p>Results</p> <p>It was found that the incidence rates from the post-operative anxiety score of the study group were lower than those of the control group (p < .05). The results of this research demonstrated that gyneoncologic surgery patients who were given systematic preoperative instruction felt less anxious than the ones who were given merely a routine nursing care.</p> <p>Conclusions</p> <p>Results of this study suggest that preoperative instruction programs aiming at informing gyneoncologic surgery patients at the preoperative stage should be organized in hospitals and have an essential role.</p

    On the shape and likelihood of oceanic rogue waves

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    We consider the observation and analysis of oceanic rogue waves collected within spatio-Temporal (ST) records of 3D wave fields. This class of records, allowing a sea surface region to be retrieved, is appropriate for the observation of rogue waves, which come up as a random phenomenon that can occur at any time and location of the sea surface. To verify this aspect, we used three stereo wave imaging systems to gather ST records of the sea surface elevation, which were collected in different sea conditions. The wave with the ST maximum elevation (happening to be larger than the rogue threshold 1.25H s) was then isolated within each record, along with its temporal profile. The rogue waves show similar profiles, in agreement with the theory of extreme wave groups. We analyze the rogue wave probability of occurrence, also in the context of ST extreme value distributions, and we conclude that rogue waves are more likely than previously reported; the key point is coming across them, in space as well as in time. The dependence of the rogue wave profile and likelihood on the sea state conditions is also investigated. Results may prove useful in predicting extreme wave occurrence probability and strength during oceanic storms

    Geometric numerical schemes for the KdV equation

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    Geometric discretizations that preserve certain Hamiltonian structures at the discrete level has been proven to enhance the accuracy of numerical schemes. In particular, numerous symplectic and multi-symplectic schemes have been proposed to solve numerically the celebrated Korteweg-de Vries (KdV) equation. In this work, we show that geometrical schemes are as much robust and accurate as Fourier-type pseudo-spectral methods for computing the long-time KdV dynamics, and thus more suitable to model complex nonlinear wave phenomena.Comment: 22 pages, 14 figures, 74 references. Other author's papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh

    Functional identification of biological neural networks using reservoir adaptation for point processes

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    The complexity of biological neural networks does not allow to directly relate their biophysical properties to the dynamics of their electrical activity. We present a reservoir computing approach for functionally identifying a biological neural network, i.e. for building an artificial system that is functionally equivalent to the reference biological network. Employing feed-forward and recurrent networks with fading memory, i.e. reservoirs, we propose a point process based learning algorithm to train the internal parameters of the reservoir and the connectivity between the reservoir and the memoryless readout neurons. Specifically, the model is an Echo State Network (ESN) with leaky integrator neurons, whose individual leakage time constants are also adapted. The proposed ESN algorithm learns a predictive model of stimulus-response relations in in vitro and simulated networks, i.e. it models their response dynamics. Receiver Operating Characteristic (ROC) curve analysis indicates that these ESNs can imitate the response signal of a reference biological network. Reservoir adaptation improved the performance of an ESN over readout-only training methods in many cases. This also held for adaptive feed-forward reservoirs, which had no recurrent dynamics. We demonstrate the predictive power of these ESNs on various tasks with cultured and simulated biological neural networks

    Bi-allelic <em>ACBD6</em> variants lead to a neurodevelopmental syndrome with progressive and complex movement disorders

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    \ua9 The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain. The acyl-CoA-binding domain-containing protein 6 (ACBD6) is ubiquitously expressed, plays a role in the acylation of lipids and proteins and regulates the N-myristoylation of proteins via N-myristoyltransferase enzymes (NMTs). However, its precise function in cells is still unclear, as is the consequence of ACBD6 defects on human pathophysiology. Using exome sequencing and extensive international data sharing efforts, we identified 45 affected individuals from 28 unrelated families (consanguinity 93%) with bi-allelic pathogenic, predominantly loss-of-function (18/20) variants in ACBD6. We generated zebrafish and Xenopus tropicalis acbd6 knockouts by CRISPR/Cas9 and characterized the role of ACBD6 on protein N-myristoylation with myristic acid alkyne (YnMyr) chemical proteomics in the model organisms and human cells, with the latter also being subjected further to ACBD6 peroxisomal localization studies. The affected individuals (23 males and 22 females), aged 1-50 years, typically present with a complex and progressive disease involving moderate-to-severe global developmental delay/intellectual disability (100%) with significant expressive language impairment (98%), movement disorders (97%), facial dysmorphism (95%) and mild cerebellar ataxia (85%) associated with gait impairment (94%), limb spasticity/hypertonia (76%), oculomotor (71%) and behavioural abnormalities (65%), overweight (59%), microcephaly (39%) and epilepsy (33%). The most conspicuous and common movement disorder was dystonia (94%), frequently leading to early-onset progressive postural deformities (97%), limb dystonia (55%) and cervical dystonia (31%). A jerky tremor in the upper limbs (63%), a mild head tremor (59%), parkinsonism/hypokinesia developing with advancing age (32%) and simple motor and vocal tics were among other frequent movement disorders. Midline brain malformations including corpus callosum abnormalities (70%), hypoplasia/agenesis of the anterior commissure (66%), short midbrain and small inferior cerebellar vermis (38% each) as well as hypertrophy of the clava (24%) were common neuroimaging findings. Acbd6-deficient zebrafish and Xenopus models effectively recapitulated many clinical phenotypes reported in patients including movement disorders, progressive neuromotor impairment, seizures, microcephaly, craniofacial dysmorphism and midbrain defects accompanied by developmental delay with increased mortality over time. Unlike ACBD5, ACBD6 did not show a peroxisomal localization and ACBD6-deficiency was not associated with altered peroxisomal parameters in patient fibroblasts. Significant differences in YnMyr-labelling were observed for 68 co- and 18 post-translationally N-myristoylated proteins in patient-derived fibroblasts. N-myristoylation was similarly affected in acbd6-deficient zebrafish and X. tropicalis models, including Fus, Marcks and Chchd-related proteins implicated in neurological diseases. The present study provides evidence that bi-allelic pathogenic variants in ACBD6 lead to a distinct neurodevelopmental syndrome accompanied by complex and progressive cognitive and movement disorders

    Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

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    Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population
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