Fast Normal Approximation of Point Clouds in Screen Space

Displaying large point clouds of mainly planar point distributions yet comes with large restrictions regarding the surface normal and surface reconstruction. Point data needs to be clustered or traversed to extract a local neighborhood which is necessary to retrieve surface information. We propose using the rendering pipeline to circumvent a pre-computation of the neighborhood in world space to perform a fast approximation of the surface in screen space. We present and compare three different methods for surface reconstruction within a post-process. These methods range from simple approximations to the definition of a tensor surface. All these methods are designed to run at interactive frame-rates. We also present a correction method to increase reconstruction quality, while preserving interactive frame-rates. Our results indicate, that the on-the-fly computation of surface normals is not a limiting factor on modern GPUs. As the surface information is generated during the post-process, only the target display size is the limiting factor. The performance is independent of the point cloud’s size

Medical use of cannabis in Switzerland: analysis of approved exceptional licences

In recent years, the Swiss Federal Office of Public Health (FOPH) granted exceptional licenses for the medical use of cannabinoids, typically for 6 months with possible extensions. A systematic review of cannabinoids for medical use commissioned by the FOPH supports the use of cannabinoids for the treatment of chronic pain and spasticity. However, little is known about the patients treated with cannabinoids. We aimed to study medical uses of cannabinoids as part of the FOPH's programme of exceptional licenses.; We examined all requests for medical use of cannabinoids sent to FOPH in 2013 and 2014. A standardised data sheet was developed to extract data from the files of approved requests. We extracted the duration of the licence, the year it was granted, and the payer of the therapy. At the level of the patient we collected the date of birth, sex, region of residence, diagnosis and the indication. Ethical approval was granted by the Ethics Committee of the Canton of Bern.; We analysed 1193 patients licenced for cannabinoid treatment in 2013 or 2014. During 2013, 542 patients were treated under the exceptional licencing programme (332 requesting physicians) compared with 825 in 2014 (446 physicians). Over half of patients (685; 57%) were women. The mean age was 57 years (standard deviation 15.0), chronic pain (49%) and spasticity (40%) were the most common symptoms, and co-medication was reported for 39% of patients. Seventy-eight different diagnoses were recorded, including multiple sclerosis (257 patients, 22%), soft tissue disorders (119, 10%), dorsalgia (97, 8.1%), spinal muscular atrophy (65, 5.5%) and paraplegia/tetraplegia (62, 5.2%). Licence extensions were granted to 143 patients (26.4%) in 2013 and 324 patients (39.3%) in 2014. There were substantial regional variations of the rates of patients treated with cannabinoids. On average, eight patients per 100 000 residents received an exceptional licence. Most patients (1083, 91%) paid out of pocket.; Exceptional licences for medical use of cannabinoids have increased substantially in Switzerland, with the programme including patients with a wide range of conditions

Vacancy patterning and patterning vacancies: controlled self-assembly of fullerenes on metal surfaces

A density functional theory study accounting for van der Waals interactions reveals the potential of metal surface vacancies as anchor points for the construction of user-defined 2D patterns of adsorbate molecules via a controlled self-assembly process. Vice versa, energetic criteria indicate the formation of regular adsorbate-induced vacancies after adsorbate self-assembly on clean surfaces. These processes are exemplified by adsorbing C60 fullerene on Al(111), Au(111), and Be(0001) surfaces with and without single, triple, and septuple atom pits. An analysis of vacancy-adatom formation energetics precedes the study of the adsorption processes

Learning to Run challenge solutions: Adapting reinforcement learning methods for neuromusculoskeletal environments

In the NIPS 2017 Learning to Run challenge, participants were tasked with building a controller for a musculoskeletal model to make it run as fast as possible through an obstacle course. Top participants were invited to describe their algorithms. In this work, we present eight solutions that used deep reinforcement learning approaches, based on algorithms such as Deep Deterministic Policy Gradient, Proximal Policy Optimization, and Trust Region Policy Optimization. Many solutions use similar relaxations and heuristics, such as reward shaping, frame skipping, discretization of the action space, symmetry, and policy blending. However, each of the eight teams implemented different modifications of the known algorithms.Comment: 27 pages, 17 figure

Selective Area Growth of PbTe Nanowire Networks on InP

Hybrid semiconductor–superconductor nanowires are promising candidates as quantum information processing devices. The need for scalability and complex designs calls for the development of selective area growth techniques. Here, the growth of large scale lead telluride (PbTe) networks is introduced by molecular beam epitaxy. The group IV-VI lead-salt semiconductor is an attractive material choice due to its large dielectric constant, strong spin-orbit coupling, and high carrier mobility. A crystal re-orientation process during the initial growth stages leads to single crystalline nanowire networks despite a large lattice mismatch, different crystal structure, and diverging thermal expansion coefficient to the indium phosphide (InP) substrate. The high quality of the resulting material is confirmed by Hall bar measurements, indicating mobilities up to 5600 cm2 (Vs)−1, and Aharonov–Bohm experiments, indicating a low-temperature phase coherence length exceeding 21 µm. Together, these properties show the high potential of the system as a basis for topological networks.</p

Hindered rolling and friction anisotropy in supported carbon nanotubes

Carbon nanotubes (CNTs) are well known for their exceptional thermal, mechanical and electrical properties. For many CNT applications it is of the foremost importance to know their frictional properties. However, very little is known about the frictional forces between an individual nanotube and a substrate or tip. Here, we present a combined theoretical and experimental study of the frictional forces encountered by a nanosize tip sliding on top of a supported multiwall CNT along a direction parallel or transverse to the CNT axis. Surprisingly, we find a higher friction coefficient in the transverse direction compared with the parallel direction. This behaviour is explained by a simulation showing that transverse friction elicits a soft 'hindered rolling' of the tube and a frictional dissipation that is absent, or partially absent for chiral CNTs, when the tip slides parallel to the CNT axis. Our findings can help in developing better strategies for large-scale CNT assembling and sorting on a surface.Comment: 8 pages, 5 figure

Whole-genome sequencing for drug resistance profile prediction in Mycobacterium tuberculosis

Whole-genome sequencing allows rapid detection of drug-resistant; Mycobacterium tuberculosis; isolates. However, the availability of high-quality data linking quantitative phenotypic drug susceptibility testing (DST) and genomic data have thus far been limited. We determined drug resistance profiles of 176 genetically diverse clinical; M. tuberculosis; isolates from the Democratic Republic of the Congo, Ivory Coast, Peru, Thailand, and Switzerland by quantitative phenotypic DST for 11 antituberculous drugs using the BD Bactec MGIT 960 system and 7H10 agar dilution to generate a cross-validated phenotypic DST readout. We compared DST results with predicted drug resistance profiles inferred by whole-genome sequencing. Classification of strains by the two phenotypic DST methods into resistotype/wild-type populations was concordant in 73 to 99% of cases, depending on the drug. Our data suggest that the established critical concentration (5 mg/liter) for ethambutol resistance (MGIT 960 system) is too high and misclassifies strains as susceptible, unlike 7H10 agar dilution. Increased minimal inhibitory concentrations were explained by mutations identified by whole-genome sequencing. Using whole-genome sequences, we were able to predict quantitative drug resistance levels for the majority of drug resistance mutations. Predicting quantitative levels of drug resistance by whole-genome sequencing was partially limited due to incompletely understood drug resistance mechanisms. The overall sensitivity and specificity of whole-genome-based DST were 86.8% and 94.5%, respectively. Despite some limitations, whole-genome sequencing has the potential to infer resistance profiles without the need for time-consuming phenotypic methods

Unagreement is an illusion

This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s11049-015-9311-yThis paper proposes an analysis of unagreement, a phenomenon involving an apparent mismatch between a definite third person plural subject and first or second person plural subject agreement observed in various null subject languages (e.g. Spanish, Modern Greek and Bulgarian), but notoriously absent in others (e.g. Italian, European Portuguese). A cross-linguistic correlation between unagreement and the structure of adnominal pronoun constructions suggests that the availability of unagreement depends on whether person and definiteness are hosted by separate heads (in languages like Greek) or bundled on a single head (i.e. pronominal determiners in languages like Italian). Null spell-out of the head hosting person features high in the extended nominal projection of the subject leads to unagreement. The lack of unagreement in languages with pronominal determiners results from the interaction of their syntactic structure with the properties of the vocabulary items realising the head encoding both person and definiteness. The analysis provides a principled explanation for the cross-linguistic distribution of unagreement and suggests a unified framework for deriving unagreement, adnominal pronoun constructions, personal pronouns and pro