Guide to the use of Mariner images

Planetary imaging from unmanned spacecraft, almost exclusively done by digital systems, is examined. The Mars Mariner 9 television camera, representative of such systems, is considered. Each image consists of 700 lines, each containing 832 picture elements, or pixels. Each pixel contains nine binary bits of information capable of displaying 512 discrete brightness levels. Several problems inherent in television systems are discussed. These include nonuniform target response, residual images, noise, and blemishes. These defects can be removed to some extent by decalibration of the image. The final product is geometrically corrected for camera distortion and photometrically corrected. Several versions of the decalibrated images are available. The most generally useful are the geometrically corrected images with enhanced contrast. The Mariner 10 imaging of Mercury is briefly discussed

The Fibrinolysis Renaissance

Open Access via the Elsevier agreement Figures were created with BioRender.com and exported under a paid subscription.Peer reviewedPublisher PD

Let's cross-link: diverse functions of the promiscuous cellular transglutaminase factor XIII-A

Factor XIII is a tranglutaminase enzyme that catalyzes the formation of ε‐(γ‐glutamyl)lysyl isopeptide bonds in protein substrates. The plasma form, FXIII‐A2B2, has an established function in hemostasis, where its primary substrate is fibrin. A deficiency in FXIII manifests as a severe bleeding diathesis, underscoring its importance in this pathway. The cellular form of the enzyme, a homodimer of the A‐subunits, denoted FXIII‐A, has not been studied in as extensive detail. FXIII‐A was generally perceived to remain intracellular, owing to the lack of a classical signal peptide for its release. In the last decade, emerging evidence has revealed that this diverse transglutaminase can be externalized from cells, by an as yet unknown mechanism, and can cross‐link extracellular substrates and participate in a number of diverse pathways. The FXIII‐A gene (F13A1) is expressed in cells of bone marrow and mesenchymal lineage, notably megakaryocytes, monocytes/macrophages, dendritic cells, chrondrocytes, osteoblasts, and preadipocytes. The biological processes that FXIII‐A is coupled with, such as wound healing, phagocytosis, and bone and matrix remodeling, reflect its expression in these cell types. This review describes the mounting evidence that this cellular transglutaminase can be externalized, usually in response to stimuli, and participate in extracellular cross‐linking reactions. A corollary of being involved in these biological pathways is the participation of FXIII‐A in pathological processes. In conclusion, the functions of this transglutaminase extend far beyond its role in hemostasis, and our understanding of this enzyme in terms of its secretion, regulation and substrates is in its infancy

Novel aspects of platelet factor XIII function

Acknowledgments The study was supported by grants FS/11/2/28579 (N.J.M.) from the British Heart Foundation and the University of Aberdeen Development Trust.Peer reviewedPostprin

Sedimentary and Structural History of Narragansett Basin

Guidebook: 55th annual meeting, October 4-6, 1963, Providence, Rhode Island: Trip

Challenges for the development of surface modified biodegradable polyester biomaterials: a chemistry perspective

The design of current implants produced from biodegradable polyesters is based on strength and rate of degradation and tailored by the choice of polyester used. However, detailed knowledge about the degradation mechanism of surface modified materials with applications in biomaterials science and tissue engineering is currently lacking. This perspective aims to outline the need for a greater focus on analyzing the degradation of modified polyesters to ensure they can fulfil their intended function and that degradation products can effectively be cleared from the body. The status of the literature regarding surface modified polyesters is summarized to illustrate the main aspects investigated in recent studies and specifically the number of studies investigating the fate of the materials upon degradation. Published by the AVS