Characterization of brick masonry: Study towards retrofitting URM walls with timber-panels

The overall purpose of this study is to explore the possibility of using timber-panels to retrofit URM walls. However, this paper only present the overall proposed experimental program together with the experimental characterization of mechanical properties of masonry components: units and mortar. The present work developed finite element numerical model that is able to predict the strength of the masonry cube, on the safe side. The numerical model was validated with an experimental test on masonry cube showing 9% difference in the maximum compressive strength of masonry. The modelling technique adopted is the detailed micro modelling where the unit and mortar were represented by their respective mechanical properties using ABAQUS. Because, the numerical results compliment what was observed during the experimental test, then the developed model can be used to predict the general behaviour of masonry wall in the subsequent study.- (undefined

Life Cycle Analysis of Innovative Technologies: Cold Formed Steel System and Cross Laminated Timber

Reducing the embodied and operational energy of buildings is a key priority for construction and real estate sectors. It is essential to prioritize materials and construction technologies with low carbon footprints for the design of new buildings. Off-site constructions systems are claimed to have the potential to deliver a low carbon build environment, but at present there are a lack of data about their real environmental impacts. This paper sheds lights on the environmental performance of two offsite technologies: cold formed steel and cross laminated timber. Specifically, the environmental impacts of a CFS technology are discussed according to six standard impact categories, which includes the global warming potential and the total use of primary energy. The study is based on a detailed cradle to gate life cycle analysis of a real case study, and discusses the impacts of both structural and non-structural components of CFS constructions. As a useful frame of reference, this work compares the environmental impacts of 1 m2 of walls and floors of CFS technology with those of cross laminated timber, which is spreading as innovative off-site technology for the development of nearly zero energy buildings, and a conventional reinforced masonry technology, which is largely adopted in the Italian construction sector. The paper concludes with the necessity to optimize structural systems to reduce the overall embodied carbon impacts

distribution and bioactivity of the ret specific d4 aptamer in three dimensional collagen gel cultures

The success of tyrosine kinase inhibitors in cancer therapy prompted intensive research efforts addressed to the development of new specific diagnostics and therapeutics. Targeting large transmembrane molecules, including receptor tyrosine kinases, is a major pharmacologic challenge. The D4 RNA-aptamer, isolated applying the Systematic Evolution of Ligand by Exponential Enrichment procedure on living cells, has been proven a specific inhibitor of the human receptor tyrosine kinase Ret. In our attempts to generate new powerful probes for in vivo applications, in the present study, we addressed the ability of D4 to preserve its biological activity in cells embedded in three-dimensional collagen gels. These matrices provide a microenvironment mimicking the cell organization as seen in vivo , thus representing a suitable tool to approach the use of the aptamer in vivo . By taking advantage of transformed fibroblasts expressing Ret as a model system, we showed that the cells maintain normal phenotype and growth patterns when cultured in three-dimensional matrices and that the D4 aptamer preserves its ability to inhibit Ret on the surface of the cells embedded in collagen. Because the biological activity of RNA aptamers is largely dictated by their folded structure, the results indicate that a folded conformation of D4 responsible of its inhibiting function is preserved in the three-dimensional constructs, thus supporting its use in tumors in vivo . [Mol Cancer Ther 2008;7(10):3381–8

Performance of Prognostic Scoring Systems in MINOCA: A Comparison among GRACE, TIMI, HEART, and ACEF Scores

Background: the prognosis of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) is not benign; thus, prompting the need to validate prognostic scoring systems for this population. Aim: to evaluate and compare the prognostic performance of GRACE, TIMI, HEART, and ACEF scores in MINOCA patients. Methods: A total of 250 MINOCA patients from January 2017 to September 2021 were included. For each patient, the four scores at admission were retrospectively calculated. The primary outcome was a composite of all-cause death and acute myocardial infarction (AMI) at 1-year follow-up. The ability to predict 1-year all-cause death was also tested. Results: Overall, the tested scores presented a sub-optimal performance in predicting the composite major adverse event in MINOCA patients, showing an AUC ranging between 0.7 and 0.8. Among them, the GRACE score appeared to be the best in predicting all-cause death, reaching high specificity with low sensitivity. The best cut-off identified for the GRACE score was 171, higher compared to the cut-off of 140 generally applied to identify high-risk patients with obstructive AMI. When the scores were tested for prediction of 1-year all-cause death, the GRACE and the ACEF score showed very good accuracy (AUC = 0.932 and 0.828, respectively). Conclusion: the prognostic scoring tools, validated in AMI cohorts, could be useful even in MINOCA patients, although their performance appeared sub-optimal, prompting the need for risk assessment tools specific to MINOCA patients

The influence of autotoxicity on the dynamics of vegetation spots

Plant autotoxicity has proved to play an essential role in the behaviour of local vegetation. We analyse a reaction-diffusion-ODE model describing the interactions between vegetation, water, and autotoxicity. The presence of autotoxicity is seen to induce movement and deformation of spot patterns in some parameter regimes, a phenomenon which does not occur in classical biomass-water models. We aim to analytically quantify this novel feature, by studying travelling wave solutions in one spatial dimension. We use geometric singular perturbation theory to prove the existence of symmetric, stationary and non-symmetric, travelling pulse solutions, by constructing appropriate homoclinic orbits in the associated 5-dimensional dynamical system. In the singularly perturbed context, we perform an extensive scaling analysis of the dynamical system, identifying multiple asymptotic scaling regimes where (travelling) pulses may or may not be constructed. We show that, while the analytically constructed stationary pulse corresponds to its numerical counterpart, there is a discrepancy between the numerically observed travelling pulse and its analytical counterpart. Our findings indicate how the inclusion of an additional ODE may significantly influence the properties of classical biomass-water models of Klausmeier/Gray-Scott type. (C) 2021 Elsevier B.V. All rights reserved

Understanding Optimizations and Measuring Performances of PBKDF2

Password-based key derivation functions (KDFs) are used to generate secure keys of arbitrary length implemented in many security-related systems. The strength of these KDFs is the ability to provide countermeasures against brute-force/dictionary attacks. One of the most implemented KDFs is PBKDF2. In order to slow attackers down, PBKDF2 uses a salt and introduces computational intensive operations based on an iterated pseudorandom function. Since passwords are widely used to protect personal data and to authenticate users to access specific resources, if an application uses a small iteration count value, the strength of PBKDF2 against attacks performed on low-cost commodity hardware may be reduced. In this paper we introduce the cryptographic algorithms involved in the key derivation process, describing the optimization techniques used to speed up PBKDF2-HMAC-SHA1 in a GPU/CPU context. Finally, a testing activity has been executed on consumer-grade hardware, and experimental results are reported

Modelling competitive interactions and plant–soil feedback in vegetation dynamics

Plant–soil feedback is recognized as a causal mechanism for the emergence of vegetation patterns of the same species especially when water is not a limiting resource (e.g. humid environments) (Cartenì et al. in J Theor Biol 313:153–161, 2012. https://doi.org/10.1016/j.jtbi.2012.08.008; Marasco et al. in Bull Math Biol 76(11):2866–2883, 2014. https://doi.org/10.1007/s11538-014-0036-6). Nevertheless, in the field, plants rarely grow in monoculture but compete with other plant species. In these cases, plant–soil feedback was shown to play a key role in plant-species coexistence (Mazzoleni et al. in Ecol Model 221(23):2784–2792, 2010. https://doi.org/10.1016/j.ecolmodel.2010.08.007). Using a mathematical model consisting of four PDEs, we investigate mechanisms of inter- and intra-specific plant–soil feedback on the coexistence of two competing plant species. In particular, the model takes into account both negative and positive feedback influencing the growth of the same and the other plant species. Both the coexistence of the plant species and the dominance of a particular plant species is examined with respect to all model parameters together with the emergence of spatio-temporal vegetation patterns