65 research outputs found

    Signature of a three-dimensional photonic band gap observed on silicon inverse woodpile photonic crystals

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    We have studied the reflectivity of CMOS-compatible three-dimensional silicon inverse woodpile photonic crystals at near-infrared frequencies. Polarization-resolved reflectivity spectra were obtained from two orthogonal crystal surfaces corresponding to 1.88 pi sr solid angle. The spectra reveal broad peaks with high reflectivity up to 67 % that are independent of the spatial position on the crystals. The spectrally overlapping reflectivity peaks for all directions and polarizations form the signature of a broad photonic band gap with a relative bandwidth up to 16 %. This signature is supported with stopgaps in plane wave bandstructure calculations and with the frequency region of the expected band gap.Comment: 9 pages, 5 figure

    Toolkit for exploring ethical aspects of digital social and affective touch interactions

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    In this hands-on demonstration, people are invited to use a newly developed toolkit to scrutinize their attitude and preferences towards digital social and affective touch interactions

    Toolkit for exploring ethical aspects of digital social and affective touch interactions

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    In this hands-on demonstration, people are invited to use a newly developed toolkit to scrutinize their attitude and preferences towards digital social and affective touch interactions

    Toolkit for exploring ethical aspects of digital social and affective touch interactions

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    In this hands-on demonstration, people are invited to use a newly developed toolkit to scrutinize their attitude and preferences towards digital social and affective touch interactions

    Endovascular treatment of a patient with an aneurysm of the proper hepatic artery and a duodenal fistula

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    Aneurysms of the proper hepatic artery comprise a rare but potentially dangerous entity for which treatment is performed both surgically and endovascularly. Covered stents are generally used for endovascular treatment of such aneurysms. When the aneurysm is contaminated due to an enteric fistula, however, use of a covered stent is considered inappropriate. This case report describes the endovascular repair of a proper hepatic artery aneurysm using overlapping bare metal stents after the patient was surgically treated for duodenal hemorrhage

    Пристрій "СПРУТ" для концентрування розчиненого Cs¹³⁷ з використанням целюлозно-неорганічних сорбентів типу "БІФЕЖ"

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    В основу розробки пристрою покладено модифікацію методу лабораторної підготовки на сорбенті типу «ФЕЖЕЛ» («АНФЕЖ», «БІФЕЖ») зразка для радіонуклідного аналізу на γ-спектрометрі проб водного середовища на вміст іонів Cs¹³⁷. Методичними особливостями даної модифікації є те, що сорбент упаковують у патрон-колонку з нержавіючої сталі, робочий об’єм якої 0,08 дм³, і процес сорбції відбувається за допомогою примусового (вакуумного всмоктування) прокачування фільтрату проби через патрон із сорбентом.В основу принципа работы устройства положена модификация методов получения аналитического образца на сорбенте типа «ФЕЖЕЛ» для радиоизотопного анализа на γ-спектрометре проб водной среды на содержание ионов Cs¹³⁷. Методическими особенностями данного устройства является то, что сорбент помещается в патрон-колонку из пищевой нержавеющей стали (полезный объем 0,08 дм³), процесс сорбции происходит при прохождении раствора пробы через патрон с сорбентом посредством вакуумного всасывания

    Genome-wide association study of frontotemporal dementia identifies a <i>C9ORF72</i> haplotype with a median of 12-G4C2 repeats that predisposes to pathological repeat expansions

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    Genetic factors play a major role in frontotemporal dementia (FTD). The majority of FTD cannot be genetically explained yet and it is likely that there are still FTD risk loci to be discovered. Common variants have been identified with genome-wide association studies (GWAS), but these studies have not systematically searched for rare variants. To identify rare and new common variant FTD risk loci and provide more insight into the heritability of C9ORF72-related FTD, we performed a GWAS consisting of 354 FTD patients (including and excluding N = 28 pathological repeat carriers) and 4209 control subjects. The Haplotype Reference Consortium was used as reference panel, allowing for the imputation of rare genetic variants. Two rare genetic variants nearby C9ORF72 were strongly associated with FTD in the discovery (rs147211831: OR = 4.8, P = 9.2 × 10−9, rs117204439: OR = 4.9, P = 6.0 × 10−9) and replication analysis (P &lt; 1.1 × 10−3). These variants also significantly associated with amyotrophic lateral sclerosis in a publicly available dataset. Using haplotype analyses in 1200 individuals, we showed that these variants tag a sub-haplotype of the founder haplotype of the repeat expansion that was previously found to be present in virtually all pathological C9ORF72 G4C2 repeat lengths. This new risk haplotype was 10 times more likely to contain a C9ORF72 pathological repeat length compared to founder haplotypes without one of the two risk variants (~22% versus ~2%; P = 7.70 × 10−58). In haplotypes without a pathologic expansion, the founder risk haplotype had a higher number of repeats (median = 12 repeats) compared to the founder haplotype without the risk variants (median = 8 repeats) (P = 2.05 × 10−260). In conclusion, the identified risk haplotype, which is carried by ~4% of all individuals, is a major risk factor for pathological repeat lengths of C9ORF72 G4C2. These findings strongly indicate that longer C9ORF72 repeats are unstable and more likely to convert to germline pathological C9ORF72 repeat expansions.</p

    Common Limitations of Image Processing Metrics:A Picture Story

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    While the importance of automatic image analysis is continuously increasing, recent meta-research revealed major flaws with respect to algorithm validation. Performance metrics are particularly key for meaningful, objective, and transparent performance assessment and validation of the used automatic algorithms, but relatively little attention has been given to the practical pitfalls when using specific metrics for a given image analysis task. These are typically related to (1) the disregard of inherent metric properties, such as the behaviour in the presence of class imbalance or small target structures, (2) the disregard of inherent data set properties, such as the non-independence of the test cases, and (3) the disregard of the actual biomedical domain interest that the metrics should reflect. This living dynamically document has the purpose to illustrate important limitations of performance metrics commonly applied in the field of image analysis. In this context, it focuses on biomedical image analysis problems that can be phrased as image-level classification, semantic segmentation, instance segmentation, or object detection task. The current version is based on a Delphi process on metrics conducted by an international consortium of image analysis experts from more than 60 institutions worldwide.Comment: This is a dynamic paper on limitations of commonly used metrics. The current version discusses metrics for image-level classification, semantic segmentation, object detection and instance segmentation. For missing use cases, comments or questions, please contact [email protected] or [email protected]. Substantial contributions to this document will be acknowledged with a co-authorshi

    Understanding metric-related pitfalls in image analysis validation

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    Validation metrics are key for the reliable tracking of scientific progress and for bridging the current chasm between artificial intelligence (AI) research and its translation into practice. However, increasing evidence shows that particularly in image analysis, metrics are often chosen inadequately in relation to the underlying research problem. This could be attributed to a lack of accessibility of metric-related knowledge: While taking into account the individual strengths, weaknesses, and limitations of validation metrics is a critical prerequisite to making educated choices, the relevant knowledge is currently scattered and poorly accessible to individual researchers. Based on a multi-stage Delphi process conducted by a multidisciplinary expert consortium as well as extensive community feedback, the present work provides the first reliable and comprehensive common point of access to information on pitfalls related to validation metrics in image analysis. Focusing on biomedical image analysis but with the potential of transfer to other fields, the addressed pitfalls generalize across application domains and are categorized according to a newly created, domain-agnostic taxonomy. To facilitate comprehension, illustrations and specific examples accompany each pitfall. As a structured body of information accessible to researchers of all levels of expertise, this work enhances global comprehension of a key topic in image analysis validation.Comment: Shared first authors: Annika Reinke, Minu D. Tizabi; shared senior authors: Paul F. J\"ager, Lena Maier-Hei
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