Sinusoidally-Modulated Graphene Leaky-Wave Antenna for Electronic Beamscanning at THz

This paper proposes the concept, analysis and design of a sinusoidally-modulated graphene leaky-wave antenna with beam scanning capabilities at a fixed frequency. The antenna operates at terahertz frequencies and is composed of a graphene sheet transferred onto a back-metallized substrate and a set of polysilicon DC gating pads located beneath it. In order to create a leaky-mode, the graphene surface reactance is sinusoidally-modulated via graphene's field effect by applying adequate DC bias voltages to the different gating pads. The pointing angle and leakage rate can be dynamically controlled by adjusting the applied voltages, providing versatile beamscanning capabilities. The proposed concept and achieved performance, computed using realistic material parameters, are extremely promising for beamscanning at THz frequencies, and could pave the way to graphene-based reconfigurable transceivers and sensors.Comment: 7 pages; 10 figure

College Athletics: The Chink in the Seventh Circuit\u27s Law and Economics Armor

If any court is linked to the “law and economics” movement, it is the Seventh Circuit, home of former Judge Richard Posner, the “Chicago School,” and analysis based on markets and economics. It thus comes as a surprise that in college-athletics cases, the court has replaced economic analysis with legal formalisms. In adopting a deferential approach that would uphold nearly every rule the National Collegiate Athletic Association (NCAA) claims is related to amateurism, the court recalls the pre- Chicago School era, in which courts aggressively applied “per se” illegality based on a restraint’s form, rather than substance. While the Seventh Circuit’s detour of deference has taken several stops, this Essay focuses on the most recent, the 2018 decision in Deppe v. NCAA

Heparin - Messias or Verschlimmbesserung?

A heightened risk of thrombosis noted early on with the severe acute respiratory syndrome coronavirus 2 infection led to the widespread use of heparin anticoagulation in the coronavirus disease 2019 (COVID-19) pandemic. However, reports soon started appearing in the literature where an apparent failure of heparin to prevent thrombotic events was observed in hospitalized patients with this viral infection. In this review, we explore the likely mechanisms for heparin failure with particular relevance to COVID-19. We also explore the role of anti-Xa assays and global hemostatic tests in this context. The current controversy of dosing heparin in this disease is detailed with some possible mechanistic reasons for anticoagulant failure. We hope that lessons learnt from the use of heparin in COVID-19 could assist us in the appropriate use of this anticoagulant in the future

Optimisation de la culture de microalgues pour la production de biodiésel

Affiche présentée dans le cadre du colloque de l'ARC "La gestion de la propriété intellectuelle : courants de pensée et facteurs de succès", lors du 81e Congrès de l'Acfas à l'Université Laval, le 8 mai 2013.Le troisième prix a été décerné à Marc-Olivier Béliveau, Virginie Bertrand-Lehouillier, Jessica Carrier et Joannie Tremblay au concours des Prix étudiants 2012-2013 de l'ARC.Dans l’optique de production de biodiésel, notre projet consistait à évaluer des conditions de culture de microalgues influençant la croissance et la production lipidique. Les souches Chlorella vulgaris, Scenedesmus sp. et Pseudokirchneriella subcapitata ont été cultivées dans différents milieux, dont des eaux usées, en version immobilisée tout comme en suspension. En plus d’avoir comparé les biomasses obtenues, des analyses en contenu lipidique des cultures ont été réalisées par coloration in situ et quantification par fluorescence

Value-Compressed Sparse Column (VCSC): Sparse Matrix Storage for Redundant Data

Compressed Sparse Column (CSC) and Coordinate (COO) are popular compression formats for sparse matrices. However, both CSC and COO are general purpose and cannot take advantage of any of the properties of the data other than sparsity, such as data redundancy. Highly redundant sparse data is common in many machine learning applications, such as genomics, and is often too large for in-core computation using conventional sparse storage formats. In this paper, we present two extensions to CSC: (1) Value-Compressed Sparse Column (VCSC) and (2) Index- and Value-Compressed Sparse Column (IVCSC). VCSC takes advantage of high redundancy within a column to further compress data up to 3-fold over COO and 2.25-fold over CSC, without significant negative impact to performance characteristics. IVCSC extends VCSC by compressing index arrays through delta encoding and byte-packing, achieving a 10-fold decrease in memory usage over COO and 7.5-fold decrease over CSC. Our benchmarks on simulated and real data show that VCSC and IVCSC can be read in compressed form with little added computational cost. These two novel compression formats offer a broadly useful solution to encoding and reading redundant sparse data

Northern Ghana hydrogeological assessment project

Groundwater is the most viable source of potable water in northern Ghana, West Africa, especially for the 80% rural inhabitants. Millions of dollars have been expended there on groundwater-based water supply infrastructures, and these expenditures are likely to continue in coming decades. The Hydrogeological Assessment Project (HAP) of the Northern Regions of Ghana was initiated to provide scientific background for groundwater-based supply projects as well as resource management. This paper summarizes the technical approaches and results to date, which include a compilation of available data, targeted field data collection, and the development of a regional hydrogeological synthesis

Anticoagulation of cancer patients with nonâ valvular atrial fibrillation receiving chemotherapy: Guidance from the SSC of the ISTH

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150593/1/jth14478.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150593/2/jth14478_am.pd

Anticoagulation in splanchnic and cerebral vein thrombosis : an international vignette-based survey

Background: Anticoagulant treatment of splanchnic (SVT) and cerebral vein thrombosis (CVT) can be challenging due to the rarity of these conditions, the concomitantly high thrombotic and bleeding risks, and the available low-quality evidence. Objectives: To explore the current therapeutic approaches to SVT and CVT, and the rationale behind the anticoagulant treatment choice. Methods: A cross-sectional survey was conducted (October 2018-April 2019) among members of three thrombosis and hemostasis societies. The survey consisted of four vignette cases: (i) SVT secondary to transient risk factor; (ii) cirrhotic SVT with esophageal varices; (iii) CVT secondary to transient risk factor; and (iv) unprovoked CVT with intracranial hemorrhage. Results: A total of 397 physicians responded to the survey. There was wide variability in anticoagulant treatment options, starting time, and duration. Vitamin K antagonists were the commonest choice across the four vignette cases (44.2%-63.0%). The direct oral anticoagulants (DOACs) were the second commonest choice in low-bleeding-risk scenarios (27.7% in case 1, 22.9% in case 3), while parenteral anticoagulation alone was the second commonest choice in high-bleeding-risk scenarios (39.9% in case 2, 39.8% in case 4). The most frequent reasons for selecting DOACs were oral route of administration (50.6%), lack of need for laboratory monitoring (48.1%), and favorable safety profile of these drugs (43.4%). Conclusions: The results of our study showed that, despite being off-label, the DOACs were considered for the treatment of unusual-site venous thromboembolism. The wide variability among different physicians reflected the clinical difficulties and raised the need for more collaborative trials on these disorders.peer-reviewe

EEG functional connectivity prior to sleepwalking : evidence of interplay between sleep and wakefulness

Study Objectives: Although sleepwalking (somnambulism) affects up to 4% of adults, its pathophysiology remains poorly understood. Sleepwalking can be preceded by fluctuations in slow-wave sleep EEG signals, but the significance of these pre-episode changes remains unknown and methods based on EEG functional connectivity have yet to be used to better comprehend the disorder. Methods: We investigated the sleep EEG of 27 adult sleepwalkers (mean age: 29 ± 7.6 years) who experienced a somnambulistic episode during slow-wave sleep. The 20-second segment of sleep EEG immediately preceding each patient’s episode was compared with the 20-second segment occurring 2 minutes prior to episode onset. Results: Results from spectral analyses revealed increased delta and theta spectral power in the 20 seconds preceding the episodes’ onset as compared to the 20 seconds occurring 2 minutes before the episodes. The imaginary part of the coherence immediately prior to episode onset revealed (1) decreased delta EEG functional connectivity in parietal and occipital regions, (2) increased alpha connectivity over a fronto-parietal network, and (3) increased beta connectivity involving symmetric inter-hemispheric networks implicating frontotemporal, parietal and occipital areas. Conclusions: Taken together, these modifications in EEG functional connectivity suggest that somnambulistic episodes are preceded by brain processes characterized by the co-existence of arousal and deep slee