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Arterial media calcification is a severe cardiovascular complication commonly manifesting in patients with chronic kidney disease (CKD). Patients with CKD frequently undergo intravenous iron therapy to address iron deficiency. Iron is suggested to be sequestered in vascular cells, potentially leading to oxidative (lipid) stress and cell death, which are recognized as key contributors to arterial calcification. The objective of this study was to investigate the effect of intravenous iron administration on CKD-induced arterial media calcification. Therefore, adenine-induced CKD rats were treated intravenously with iron and checked for arterial iron deposition and calcification, as well as for ferritin and lipid peroxidation markers. Additionally, arterial sections from patients with CKD who were dialysis dependent were analyzed for these parameters. This study showed that intravenous iron administration in CKD rats led to arterial iron deposition and a lipid peroxidation signature. CKD-induced arterial calcification was increased upon iron treatment and correlated with arterial iron accumulation and lipid peroxidation markers. Patients with CKD who were dialysis dependent showed arterial iron accumulation and elevated lipid peroxidation, but a direct correlation with arterial calcification was lacking. Taken together, iron treatment is suggested as a potential contributor to the calcification process, instead of being a predominant factor, thereby emphasizing the complexity of arterial calcification as a multifactorial disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland., (© 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

Arterial media calcification or pathological deposition of calcium-phosphate crystals in the vessel wall contributes significantly to the high mortality rate observed in patients with CKD. Extracellular nucleotides (ie, ATP or UTP) regulate the arterial calcification process by interacting with (1) purinergic receptors and (2) breakdown via ecto-nucleotidases, such as ectonucleotide pyrophosphatase/phosphodiesterase NPP1 or NPP3, affecting the local levels of calcification inhibitor, pyrophosphate, and stimulator inorganic phosphate (PP i /P i ratio). Also, it has been shown that ATP analogs (ie, β,γ-methylene-ATP [β,γ-meATP]) inhibit vascular smooth muscle cell calcification in vitro. In the first experiment, daily dosing of β,γ-meATP (2 mg/kg) was investigated in rats fed a warfarin diet to trigger the development of non-CKD-related arterial medial calcifications. This study showed that β,γ-meATP significantly lowered the calcium scores in the aorta and peripheral vessels in warfarin-exposed rats. In a second experiment, daily dosing of 4 mg/kg β,γ-meATP and its metabolite medronic acid (MDP) was analyzed in rats fed an adenine diet to promote the development of CKD-related arterial medial calcification. Administration of β,γ-meATP and MDP did not significantly decrease aortic calcification scores in this model. Moreover, both compounds induced deleterious effects on physiological bone mineralization, causing an imminent risk for worsening the already compromised bone status in CKD. Due to this, it was not possible to raise the dosage of both compounds to tackle CKD-related arterial calcification. Again, this points out the difficult task of targeting solely ectopic calcifications without negatively affecting physiological bone mineralization. On the other hand, aortic mRNA expression of Enpp1 and Enpp3 was significantly and positively associated with aortic calcification scores, suggesting that normalizing the aortic NPP1/3 activity to control values might be a possible target to treat (CKD-induced) arterial media calcifications., Competing Interests: All authors declared no competing interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society for Bone and Mineral Research.)

What does it mean to follow? In this paper, we systematically review the followership literature for the period 2017-2021. Our review shows that the followership literature suffers from three major issues that limit its validity. The followership field is dominated by a role-based approach equating direct reports with followers; empirical studies fail to study actual following behaviors, and there are no studies of downward following, which we define as any behavior or effort aimed at achieving a shared goal, carried out by an individual in a position of formal power who is influenced by one or more individuals in a position of inferior authority. Our manuscript builds on the process approach to study what it means to follow. We argue that the followership field needs to study actual followership behaviors at the micro "interaction episodes" and rely on quantitative behavioral coding. We then propose a conceptual, multi-level model that details antecedents and boundary conditions of the emergence of downward following. We conclude by discussing the organizational implications of our approach and model., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Bastardoz and Adriaensen.)

Metaheuristics are an effective and diverse class of optimization algorithms: a means of obtaining solutions of acceptable quality for otherwise intractable problems. The selection, construction, and configuration of a metaheuristic for a given problem has historically been a manually intensive process based on experience, experimentation, and reasoning by metaphor. More recently, there has been interest in automating the process of algorithm configuration. In this article, we identify shared state as an inhibitor of progress for such automation. To solve this problem, we introduce the Automated Open-Closed Principle (AOCP), which stipulates design requirements for unintrusive reuse of algorithm frameworks and automated assembly of algorithms from an extensible palette of components. We demonstrate how the AOCP enables a greater degree of automation than previously possible via an example implementation.

The Atmospheric Correction Inter-comparison eXercise (ACIX) is an international initiative with the aim to analyse the Surface Reflectance (SR) products of various state-of-the-art atmospheric correction (AC) processors. The Aerosol Optical Thickness (AOT) and Water Vapour (WV) are also examined in ACIX as additional outputs of an AC processing. In this paper, the general ACIX framework is discussed; special mention is made of the motivation to initiate this challenge, the inter-comparison protocol and the principal results. ACIX is free and open and every developer was welcome to participate. Eventually, 12 participants applied their approaches to various Landsat-8 and Sentinel-2 image datasets acquired over sites around the world. The current results diverge depending on the sensors, products and sites, indicating their strengths and weaknesses. Indeed, this first implementation of processor inter-comparison was proven to be a good lesson for the developers to learn the advantages and limitations of their approaches. Various algorithm improvements are expected, if not already implemented, and the enhanced performances are yet to be investigated in future ACIX experiments.