A Gaussian-Mixture based stochastic framework for the interpretation of spatial heterogeneity in multimodal fields

We provide theoretical formulations enabling characterization of spatial distributions of variables (such as, e.g., conductivity/permeability, porosity, vadose zone hydraulic parameters, and reaction rates) that are typical of hydrogeological and/or geochemical scenarios associated with randomly heterogeneous geomaterials and are organized on various scales of heterogeneity. Our approach and ensuing formulations embed the joint assessment of the probability distribution of a target variable and its associated spatial increments, DY, taken between locations separated by any given distance (or lag). The spatial distribution of Y is interpreted through a bimodal Gaussian mixture model. The modes of the latter correspond to an indicator random field which is in turn related to the occurrence of different processes and/or geomaterials within the domain of observation. The distribution of each component of the mixture is governed by a given length scale driving the strength of its spatial correlation. Our model embeds within a unique theoretical framework the main traits arising in a stochastic analysis of these systems. These include (i) a slight to moderate asymmetry in the distribution of Y and (ii) the occurrence of a dominant peak and secondary peaks in the distribution of DY whose importance changes with lag together with the moments of the distribution. This causes the probability distribution of increments to scale with lag in way that is consistent with observed experimental patterns. We analyze the main features of the modeling and parameter estimation framework through a set of synthetic scenarios. We then consider two experimental datasets associated with different processes and observation scales. We start with an original dataset comprising microscale reaction rate maps taken at various observation times. These are evaluated from AFM imaging of the surface of a calcite crystal in contact with a fluid and subject to dissolution. Such recent high resolution imaging techniques are key to enhance our knowledge of the processes driving the reaction. The second dataset is a well established collection of Darcy-scale air-permeability data acquired by Tidwell and Wilson (1999) [Water Resour Res, 35, 3375-3387] on a block of volcanic tuff through minipermeameters associated with various measurement scales

THE INFLUENCE OF THERMAL BRIDGES ON REFRACTORY LININGS

In this study we analyze the influence of thermal bridges caused by the presence of anchoring systems. The engineering, especially heat transfer calculation, allow the preventive definition of the most suitable insulating linings. Thanks to the thermography, it is possible to determine which are the parameters that actually influence the heat transfer process, thus to work with not only theoretical values but also actual ones. Corrective actions together with general considerations are illustrated in this study, supported by drawings, pictures and thermo graphics scans

Early predictors of smoking cessation after myocardial infarction

The determinants of long-term smoking cessation were evaluated in 80 patients who smoked cigarettes and survived a myocardial infarction. All patients underwent a program of rehabilitation and secondary prevention including in-hospital counseling and physician-guided reinforcing sessions at 1, 3, and 6 months after discharge. At 18 months of follow-up, 53 patients (66.3%) had quit smoking. Variables associated with smoking cessation were duration of hospital stay greater than or equal to 19 days (79 vs. 48%; p less than 0.005) and peak creatine phosphokinase (CPK) elevation greater than or equal to 500 U/l (76 vs. 54%; p less than 0.05). Males tended to quit in higher proportion than females (68 vs. 44%). Age, prior myocardial infarction, other cardiovascular risk factors, infarction location, Killip class at entry, and duration of stay in coronary care unit did not significantly affect the quitting rates. Logistic regression analysis singled out the duration of hospital stay as a significant predictor of smoking cessation (p less than 0.005). Early and intensive secondary prevention during the hospital stay is crucial in promoting sustained smoking cessation after myocardial infarction

Influence of block versus random monomer distribution on the cellular uptake of hydrophilic copolymers

The use of polymers has revolutionized the field of drug delivery in the past two decades. Properties such as polymer size, charge, hydrophilicity, or branching have all been shown to play an important role in the cellular internalization of polymeric systems. In contrast, the fundamental impact of monomer distribution on the resulting biological properties of copolymers remains poorly studied and is always only investigated for biologically active self-assembling polymeric systems. Here, we explore the fundamental influence of monomer distribution on the cellular uptake of nonaggregating and biologically passive copolymers. Reversible addition–fragmentation chain-transfer (RAFT) polymerization was used to prepare precisely defined copolymers of three hydrophilic acrylamide monomers. The cellular internalization of block copolymers was compared with the uptake of a random copolymer where monomers are statistically distributed along the chain. The results demonstrate that monomer distribution in itself has a negligible impact on copolymer uptake

Vegetating nodules following erosions on the oral cavity : a quiz

Acta Derm Venereol 95 © 2015 The Authors. doi: 10.2340/00015555-1936 Journal Compilation © 2015 Acta Dermato-Venereologica. ISSN 0001-5555 A 68-year-old Italian man presented with a 7-month history of multiple erosions on the trunk as well as lips and oral cavity. Before admission to our department, he was treated in another institution with systemic corticosteroids (oral prednisone at the initial dose of 1 mg/kg/day, with progressively tapering dosages for 2 months) and other immunosuppressants, such as azathioprine (1.25 mg/kg/ day for 2 months), intravenous immunoglobulins (one cycle consisting of one infusion of 400 mg/kg/day for 5 consecutive days), and rituximab (one cycle consisting of one infusion of 375 mg/m2/every week for 4 weeks), achieving resolution of the cutaneous manifestations but without control of the oral involvement. Upon admission, he had multiple lip and oral erosions (Fig. 1a). In the following days, he developed erythematous-violaceous vegetating nodules that coalesced into ulcerated plaques on the lips and tongue (Fig. 1b). The patient's general condition was compromised; he was asthenic and, due to dysphagia, had lost about 15 kg in the last 3 months. Staging fibroscopy revealed nodules that induced marked stenosis of the larynx and pharynx (Fig. 1c). Within a few days, an emergency tracheotomy was required because of acute dyspnea. Biopsy specimens from a nodule were submitted for histology (Fig. 1d)

Multifaceted Aspects of Metabolic Plasticity in Human Cholangiocarcinoma : An Overview of Current Perspectives

Cholangiocarcinoma (CCA) is a deadly tumor without an effective therapy. Unique metabolic and bioenergetics features are important hallmarks of tumor cells. Metabolic plasticity allows cancer cells to survive in poor nutrient environments and maximize cell growth by sustaining survival, proliferation, and metastasis. In recent years, an increasing number of studies have shown that specific signaling networks contribute to malignant tumor onset by reprogramming metabolic traits. Several evidences demonstrate that numerous metabolic mediators represent key-players of CCA progression by regulating many signaling pathways. Besides the well-known Warburg effect, several other different pathways involving carbohydrates, proteins, lipids, and nucleic acids metabolism are altered in CCA. The goal of this review is to highlight the main metabolic processes involved in the cholangio-carcinogeneis that might be considered as potential novel druggable candidates for this disease

Macrophage ferroportin is essential for stromal cell proliferation in wound healing

Iron recycling by macrophages is essential for erythropoiesis, but may be also relevant for iron redistribution to neighbouring cells at the local tissue level. Using mice with iron retention in macrophages due to targeted inactivation of the iron exporter ferroportin, we investigated the role of macrophage iron release in hair follicle cycling and wound healing, a complex process leading to major clinical problems, if impaired. Genetic deletion of ferroportin in macrophages resulted in iron deficiency and decreased proliferation in epithelial cells, which consequently impaired hair follicle growth and caused transient alopecia. Hair loss was not related to systemic iron deficiency or anemia, thus indicating the necessity of local iron release from macrophages. Inactivation of macrophage ferroportin also led to delayed skin wound healing with defective granulation tissue formation and diminished fibroplasia. Iron retention in macrophages had no impact on the inflammatory processes accompanying wound healing, but affected stromal cells proliferation, blood and lymphatic vessels formation, and fibrogenesis. Our findings reveal that iron/ferroportin plays a largely underestimated role in the macrophage trophic function in skin homeostasis and repair

Induction of erythroferrone in healthy humans by micro-dose recombinant erythropoietin or high-altitude exposure

The erythropoietin (Epo)-erythroferrone (ERFE)-hepcidin axis coordinates erythropoiesis and iron homeostasis. While mouse studies have established that Epo-induced ERFE production represses hepcidin synthesis by inhibiting hepatic BMP/SMAD signaling, evidence for the role of ERFE in humans is limited. To investigate the role of ERFE as a physiological erythroid regulator in humans, we conducted two studies: first, 24 males received six injections of saline (placebo), recombinant Epo (rhEpo) 20 UI kg-1 (micro-dose) or 50 UI kg-1 (low-dose). Second, we quantified ERFE in 22 subjects exposed to high altitude (3800 m) for 15 hours. In the first study, total hemoglobin mass (Hbmass) increased after low- but not after micro-dose injections, when compared to placebo. Serum ERFE levels were enhanced by rhEpo, remaining higher than after placebo for 48 (micro-dose) or 72 hours (low-dose) post-injections. Conversely, hepcidin levels decreased when Epo and ERFE arose, before any changes in serum iron parameters occurred. In the second study, serum Epo and ERFE increased at high altitude. The present results demonstrate that in healthy humans ERFE responds to slightly increased Epo levels not associated with Hbmass expansion and down-regulates hepcidin in an apparently iron-independent way. Notably, ERFE flags micro-dose Epo, thus holding promise as novel anti-doping biomarker