Bacterially mediated mineralisation processes lead to biodeterioration of artworks in Maltese catacombs

Mineral structures formed by bacterial and microalgal biofilms growing on the archaeological surface in Maltese hypogea were studied using Energy Dispersive X-Ray Spectroscopy (EDS) coupled to Environmental Scanning Electron Microscopy (ESEM), X-ray micro-diffraction (XRD) and X-ray fluorescence (XRF). These techniques have shown that mineral structures having different morphologies and chemical composition were associated with the microorganisms in the subaerophytic biofilm. Salt efflorescences and mineral deposits on the archaeological surface were often formed from gypsum (CaSO₄? 2H₂O), halite (NaCl) and calcite (CaCO₃). Biogenic carbonates produced by microbial activities were a common occurrence. These assumed different forms, such as the production of mineral coats around cyanobacterial sheaths and the occurrence of calcite fibres with different morphologies on the surface of the biofilms. Moreover, vaterite (CaCO₃) spherulites which appeared hollow in cross-section were observed. The presence of struvite was recorded from one catacomb site. These investigations have facilitated the study of the neoformation of metastable minerals by microbially mediated processes, which potentially contribute to a better understanding of the biodeterioration of artworks in Maltese palaeo-Christian catacombs.     

Towards a model for the study of written procedure following in dynamic environments

Flight safety relies on a large number of automatisms and on strict written procedure following. This article presents a psycho-cognitive analysis of the procedure following task. Consequently, we have proposed a model called SPEED (Suivi de Procédures Ecrites dans les Environnements Dynamiques: Written Procedure Following in Dynamic Environments). SPEED enables the understanding of the use of written procedure in dynamic environments. It describes the reasons why pilots do not follow procedures as the manufacturers and airlines require. SPEED breaks down the activities involved in the use of procedures into nine stages: (1) detecting triggering conditions, (2) elaborating a diagnosis, (3) determining whether a procedure is needed, (4) accessing and searching for the appropriate written procedure, (5) reading and understanding the items of the procedure, (6) assessing the relevance of the procedure, (7) planning actions, (8) executing the planned actions and (9) evaluating the outcome of actions. SPEED is not as a sequential model. It is an iterative model, where some steps may be optional.     

Discovery of Potent Pyrazoline-Based Covalent SARS-CoV-2 Main Protease Inhibitors**

While vaccines and antivirals are now being deployed for the current SARS-CoV-2 pandemic, we require additional antiviral therapeutics to not only effectively combat SARS-CoV-2 and its variants, but also future coronaviruses. All coronaviruses have relatively similar genomes that provide a potential exploitable opening to develop antiviral therapies that will be effective against all coronaviruses. Among the various genes and proteins encoded by all coronaviruses, one particularly “druggable” or relatively easy-to-drug target is the coronavirus Main Protease (3CL^pro or Mpro), an enzyme that is involved in cleaving a long peptide translated by the viral genome into its individual protein components that are then assembled into the virus to enable viral replication in the cell. Inhibiting Mpro with a small-molecule antiviral would effectively stop the ability of the virus to replicate, providing therapeutic benefit. In this study, we have utilized activity-based protein profiling (ABPP)-based chemoproteomic approaches to discover and further optimize cysteine-reactive pyrazoline-based covalent inhibitors for the SARS-CoV-2 Mpro. Structure-guided medicinal chemistry and modular synthesis of di- and tri-substituted pyrazolines bearing either chloroacetamide or vinyl sulfonamide cysteine-reactive warheads enabled the expedient exploration of structure-activity relationships (SAR), yielding nanomolar potency inhibitors against Mpro from not only SARS-CoV-2, but across many other coronaviruses. Our studies highlight promising chemical scaffolds that may contribute to future pan-coronavirus inhibitors.     

Gap Junctions between Endothelial Cells Are Disrupted by Circulating Extracellular Vesicles from Sickle Cell Patients with Acute Chest Syndrome

Intercellular junctions maintain the integrity of the endothelium. We previously found that the adherens and tight junctions between endothelial cells are disrupted by plasma extracellular vesicles from patients with sickle cell disease (especially those with Acute Chest Syndrome). In the current study, we evaluated the effects of these vesicles on endothelial gap junctions. The vesicles from sickle cell patients (isolated during episodes of Acute Chest Syndrome) disrupted gap junction structures earlier and more severely than the other classes of intercellular junctions (as detected by immunofluorescence). These vesicles were much more potent than those isolated at baseline from the same subject. The treatment of endothelial cells with these vesicles led to reduced levels of connexin43 mRNA and protein. These vesicles severely reduced intercellular communication (transfer of microinjected Neurobiotin). Our data suggest a hierarchy of progressive disruption of different intercellular connections between endothelial cells by circulating extracellular vesicles that may contribute to the pathophysiology of the endothelial disturbances in sickle cell disease.     

NO LOOKING AFTER THE INTERNET

What are the possibilities of learning from difficult images in an era in which digital technologies have made photographs of social violence ubiquitous? This article critically reflects on this question through an account of the curatorial experiments, dialogic contests and pedagogical failures encountered in organizing No Looking After the Internet: a “looking group” that has met since 2012 which invites participants to look at an image (or a series of images) they are unfamiliar with, and “read” the image out loud together. Premised on the idea that it is not just what photographs depict that is difficult, but the interpretive process we encounter as viewers, No Looking foregrounds the latent knowledge that emerges from grappling with the photographic evidence difficult images offer us. Focusing on two sessions in which participants’ abilities to engage difficult knowledge broke down, the essay presents the first attempt at articulating a visual methodology that asks what we want from photographs in a post-internet age. In so doing, it builds on the psychoanalytically inflected work of pedagogical theorists Deborah Britzman and Roger Simon, which is cautiously optimistic about the spectator’s capacity for ethically engaging the suffering of others.     

A Grid‐enabled problem‐solving environment for advanced reservoir uncertainty analysis

Uncertainty analysis is critical for conducting reservoir performance prediction. However, it is challenging because it relies on (1) massive modeling‐related, geographically distributed, terabyte, or even petabyte scale data sets (geoscience and engineering data), (2) needs to rapidly perform hundreds or thousands of flow simulations, being identical runs with different models calculating the impacts of various uncertainty factors, (3) an integrated, secure, and easy‐to‐use problem‐solving toolkit to assist uncertainty analysis. We leverage Grid computing technologies to address these challenges. We design and implement an integrated problem‐solving environment ResGrid to effectively improve reservoir uncertainty analysis. The ResGrid consists of data management, execution management, and a Grid portal. Data Grid tools, such as metadata, replica, and transfer services, are used to meet massive size and geographically distributed characteristics of data sets. Workflow, task farming, and resource allocation are used to support large‐scale computation. A Grid portal integrates the data management and the computation solution into a unified easy‐to‐use interface, enabling reservoir engineers to specify uncertainty factors of interest and perform large‐scale reservoir studies through a web browser. The ResGrid has been used in petroleum engineering. Copyright © 2008 John Wiley & Sons, Ltd.     

Endogenous differentiation of services

This paper presents a model of competition between firms whose production involves increasingreturns. More than one firm can be active on the market only if they differentiate their product onquality grounds. This model can be applied to the case of vertical differentiation: the quality of a product is a measurable attribute and all the consumers agree on the ranking of qualities; or to the case of horizontal differentiation: the product is differentiated in varieties: each consumer has a prefered variety. The long distance telecommunication market in the United States is an example of competition on quality grounds. The authors show that acompetitive equilibrium exists under very weak assumptions. At equilibrium each firm has a market share gathering consumers with similar tastes.     

Ecologically benign polymers: the case of maleic polyelectrolytes

The paper discusses a series of results that evidence the favorable effect of maleic polyelectrolytes in different fields in which a protective action of the environment is attained: (i) the exploitation of geothermal water, which is a cleaner source of energy; (ii) the improvement or preservation of the structure of agricultural soils; (iii) the substitution of phosphates in detergents; and (iv) the reduction of chromium load of effluents from tanning plants.     

Modification of the surface properties of bitumen and asphaltenes following treatment with sulphur at 140 °C

Bitumen was treated with elemental sulphur at 140 °C and changes in the surface properties of the bitumen and the corresponding asphaltenes were studied. The bitumen-sulphur interfacial tension is low, a fact which accounts for the ease of formation of a sulphur-bitumen emulsion. The sulphur-treated bitumen shows increased adsorption characteristics, especially for a basic surface, such as magnesium oxide. The change in the polar character of the asphaltenes, as revealed by the contact-angle method, is responsible for this behaviour.     

Apparatus Exposure Produces Profound Declines in Conditioned Nictitating-Membrane Responses to Discrete Conditioned Stimuli by the Rabbit (Oryctolagus cuniculus).

The present experiments demonstrated that in the rabbit (Oryctolagus cuniculus) nictitacing-membrane (NM) preparation, exposure to the experimental apparatus produces profound declines in conditioned responding to a discrete conditioned stimulus (CS; Experiments 1, 2A, and 3). Moreover, this decremental effect is at most attenuated in only a minor way when the unconditioned stimulus (US) is presented during exposure to the apparatus (Experiment 2B). Controls for retention loss (Experiments 1 and 3) and for handling and placement in a different context (Experiment 3) did not produce significant declines in responding. These findings challenge theories of extinction that rely primarily on context-US associations but are more consistent with theories that assume context-CS-US associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)