The Duals of *-Operator Frames for End*A(H)

Frames play significant role in signal and image processing, which leads to many applications in differents fields. In this paper we define the dual of ∗-operator frames and we show their propreties obtained in Hilbert A-modules and we establish some results

Maximal Dissent: a State-Dependent Way to Agree in Distributed Convex Optimization

Consider a set of agents collaboratively solving a distributed convex optimization problem, asynchronously, under stringent communication constraints. In such situations, when an agent is activated and is allowed to communicate with only one of its neighbors, we would like to pick the one holding the most informative local estimate. We propose new algorithms where the agents with maximal dissent average their estimates, leading to an information mixing mechanism that often displays faster convergence to an optimal solution compared to randomized gossip. The core idea is that when two neighboring agents whose distance between local estimates is the largest among all neighboring agents in the network average their states, it leads to the largest possible immediate reduction of the quadratic Lyapunov function used to establish convergence to the set of optimal solutions. As a broader contribution, we prove the convergence of max-dissent subgradient methods using a unified framework that can be used for other state-dependent distributed optimization algorithms. Our proof technique bypasses the need of establishing the information flow between any two agents within a time interval of uniform length by intelligently studying convergence properties of the Lyapunov function used in our analysis

From bulletins to bullets to blogs and beyond: The Karen’s ongoing communication war

Geff Green focuses on the communication approaches taken by the Karen communities displaced from Burma and who live in diaspora. Apparent control and empowerment provided by new technologies may be illusive. When using media for warfare or perhaps for more innocuous public relations purposes, activists may actually create ‘ammunition’ for opponents. Targeted attacks on specific communities or ‘audiences’ have a high impact by reifying discourse in a devastating way by connecting to lived experience in the victim

American Society of Hematology 2021 guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19

Background: Coronavirus disease 2019 (COVID-19)-related critical illness and acute illness are associated with a risk of venous thromboembolism (VTE).Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness and acute illness who do not have confirmed or suspected VTE.Methods: ASH formed a multidisciplinary guideline panel and applied strict management strategies to minimize potential bias from conflicts of interest. The panel included 3 patient representatives. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic evidence reviews (up to 19 August 2020). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.Results: The panel agreed on 2 recommendations. The panel issued conditional recommendations in favor of prophylactic-intensity anticoagulation over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness or acute illness who do not have confirmed or suspected VTE.Conclusions: These recommendations were based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials comparing different intensities of anticoagulation. They will be updated using a living recommendation approach as new evidence becomes available.Thrombosis and Hemostasi

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: May 2021 update on the use of intermediate-intensity anticoagulation in critically ill patients

Background: COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE). Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE.Methods: ASH formed a multidisciplinary guideline panel that included 3 patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process by performing systematic evidence reviews (up to 5 March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update on guidelines published in February 2021.Results: The panel agreed on 1 additional recommendation. The panel issued a conditional recommendation in favor of prophylactic-intensity over intermediate-intensity anticoagulation in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE.Conclusions: This recommendation was based on low certainty in the evidence, which underscores the need for additional high-quality, randomized, controlled trials comparing different intensities of anticoagulation in critically ill patients. Other key research priorities include better evidence regarding predictors of thrombosis and bleeding risk in critically ill patients with COVID-19 and the impact of nonanticoagulant therapies (eg, antiviral agents, corticosteroids) on thrombotic risk.Thrombosis and Hemostasi

Maroc saharien et Maroc méditerranéen au Moyen-Âge : le cas des ports de Nûl Lamta et de Bad\ⁱs

International audienc

Optimisation and biological activities of bioceramic robocast scaffolds provided with an oxygen-releasing coating for bone tissue engineering applications

Hypoxia is one of the major challenges after scaffold implantation which can lead to cell necrosis and bacterial infection. Using of supplemental oxygen can increase the cell proliferation, encourage the cell differentiation and prevent the infections. Developing an engineered scaffold with a sustained oxygen release is an outstanding way for addressing the challenges of oxygen deficiency. In this study, the bioceramic scaffolds were fabricated from biphasic calcium phosphate (BCP) powder with the composition of 60 hydroxyapatite (HA) and 40 beta-tricalcium phosphate (β-TCP). The Robocasting technique was utilised for producing a porous structure comprising interpenetrated ceramic rods in a 3-dimensional tetragonal mesh. The scaffold was modelled by the finite element method (FEM) for computing the stress fields and predicting their mechanical performance. Calcium peroxide (CPO), as an oxygen-producing and antimicrobial biomaterial, was mixed with a polycaprolactone (PCL) solution and was coated on the scaffolds by the dip-coating method. The coating layer possessed three different percentages of CPO (1, 3 and 5 wt). The oxygen-releasing profile proved that this design of coating-scaffold could be effective as a system of oxygen delivery. According to the antibacterial investigations, releasing of CPO from the scaffolds could inhibit the growth of E. coli and S. aureus. SBF tests confirmed that the coated scaffolds because of CPO particles on their surface presented superior apatite precipitation in comparison with the uncoated one. The differentiated osteoblastic function was monitored by measuring the alkaline phosphatase (ALP) activity. The coated BCP scaffolds with 3 and 5 CPO exhibited higher ALP activity compared to the other samples. The results demonstrated that the proposed bioceramic-based scaffolds containing oxygen-generating coating could be optimised to supply an antibacterial performance, ideal mechanical properties, improved ALP activity and higher apatite formation ability. Therefore, these scaffolds can be a promising candidate for applying in bone tissue engineering. © 2018 Elsevier Ltd and Techna Group S.r.l

3D�printed biphasic calcium phosphate scaffolds coated with an oxygen generating system for enhancing engineered tissue survival

Tissue engineering scaffolds with oxygen generating elements have shown to be able to increase the level of oxygen and cell survivability in specific conditions. In this study, biphasic calcium phosphate (BCP) scaffolds with the composition of 60 hydroxyapatite (HA) and 40 beta-tricalcium phosphate (β-TCP), which have shown a great potential for bone tissue engineering applications, were fabricated by a direct-write assembly (robocasting) technique. Then, the three-dimensional (3D)-printed scaffolds were coated with different ratios of an oxygen releasing agent, calcium peroxide (CPO), which encapsulated within a polycaprolactone (PCL) matrix through dip-coating, and used for in situ production of oxygen in the implanted sites. The structure, composition and morphology of the prepared scaffolds were characterized by different techniques. The oxygen release kinetics and biological investigations of the scaffolds were also studied in vitro. The results showed that oxygen release behaviour was sustained and dependant on the concentration of CPO encapsulated in the PCL coating matrix. It was also demonstrated that the coated scaffolds, having 3 CPO in the coating system, could provide a great potential for promoting bone ingrowth with improving osteoblast cells viability and proliferation under hypoxic conditions. The findings indicated that the prepared scaffolds could play a significant role in engineering of large bone tissue implants with limitations in oxygen diffusion. © 201

Additive Manufacturing of Biomaterials � The Evolution of Rapid Prototyping

Biomaterials rapid prototyping (RP), recently known as additive manufacturing (AM), has appeared as a revolutionary technology, promising to transform research into medical therapeutics. RP is a layer by layer manufacturing process which directly translates computer data such as Computer Aided Design (CAD), Computer Tomography (CT), and Magnetic Resonance Imaging (MRI) into three-dimensional (3D) objects. RP technologies play a significant role in biomedical industry such as anatomical models for surgery training/planning, rehabilitation, dentistry, customized implants, drug delivery devices, tissue engineering, and organ printing. The integration of biomaterials and rapid prototyping technologies is an exciting route in developing biomaterial implants for the past decade. This review describes and classifies the RP systems into three categories of liquid-based, solid-based, and powder-based according to the initial form of their feed materials. Then, discusses possible benefits, drawbacks, and applications of each process in the field of biomaterials science and engineering. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei