Showing papers by "University of Patras published in 2017"

Imbalanced-learn: a python toolbox to tackle the curse of imbalanced datasets in machine learning

Abstract: imbalanced-learn is an open-source python toolbox aiming at providing a wide range of methods to cope with the problem of imbalanced dataset frequently encountered in machine learning and pattern recognition. The implemented state-of-the-art methods can be categorized into 4 groups: (i) under-sampling, (ii) over-sampling, (iii) combination of over-and under-sampling, and (iv) ensemble learning methods. The proposed toolbox depends only on numpy, scipy, and scikit-learn and is distributed under MIT license. Furthermore, it is fully compatible with scikit-learn and is part of the scikit-learn-contrib supported project. Documentation, unit tests as well as integration tests are provided to ease usage and contribution. Source code, binaries, and documentation can be downloaded from https://github.com/scikit-learn-contrib/imbalanced-learn.

A synthesis of radial growth patterns preceding tree mortality

Abstract: Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-conti- nental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1–100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks.

Review of recent trends in photoelectrocatalytic conversion of solar energy to electricity and hydrogen

Abstract: This work is a review of the recent trends in the photoelectrocatalytic conversion of solar energy into electricity or hydrogen. It focuses on photocatalytic fuel cells and photoelectrocatalytic water splitting systems and presents both the basic principles and the design of devices. It includes a broad review of materials employed for the construction of photoanodes, photocathodes and tandem cells and highlights the related research fields which are expected to be of interest in the near future. The review is intended to become a basic manual for new adepts to the field and at the same time a handy reference to experienced researchers.

Global distribution of particle phase state in atmospheric secondary organic aerosols

Abstract: Secondary organic aerosols (SOA) are a large source of uncertainty in our current understanding of climate change and air pollution. The phase state of SOA is important for quantifying their effects on climate and air quality, but its global distribution is poorly characterized. We developed a method to estimate glass transition temperatures based on the molar mass and molecular O:C ratio of SOA components, and we used the global chemistry climate model EMAC with the organic aerosol module ORACLE to predict the phase state of atmospheric SOA. For the planetary boundary layer, global simulations indicate that SOA are mostly liquid in tropical and polar air with high relative humidity, semi-solid in the mid-latitudes and solid over dry lands. We find that in the middle and upper troposphere SOA should be mostly in a glassy solid phase state. Thus, slow diffusion of water, oxidants and organic molecules could kinetically limit gas-particle interactions of SOA in the free and upper troposphere, promote ice nucleation and facilitate long-range transport of reactive and toxic organic pollutants embedded in SOA.

The macrolide antibiotic renaissance

Abstract: Macrolides represent a large family of protein synthesis inhibitors of great clinical interest due to their applicability to human medicine. Macrolides are composed of a macrocyclic lactone of different ring sizes, to which one or more deoxy-sugar or amino sugar residues are attached. Macrolides act as antibiotics by binding to bacterial 50S ribosomal subunit and interfering with protein synthesis. The high affinity of macrolides for bacterial ribosomes, together with the highly conserved structure of ribosomes across virtually all of the bacterial species, is consistent with their broad-spectrum activity. Since the discovery of the progenitor macrolide, erythromycin, in 1950, many derivatives have been synthesised, leading to compounds with better bioavailability and acid stability and improved pharmacokinetics. These efforts led to the second generation of macrolides, including well-known members such as azithromycin and clarithromycin. Subsequently, in order to address increasing antibiotic resistance, a third generation of macrolides displaying improved activity against many macrolide resistant strains was developed. However, these improvements were accompanied with serious side effects, leading to disappointment and causing many researchers to stop working on macrolide derivatives, assuming that this procedure had reached the end. In contrast, a recent published breakthrough introduced a new chemical platform for synthesis and discovery of a wide range of diverse macrolide antibiotics. This chemical synthesis revolution, in combination with reduction in the side effects, namely, 'Ketek effects', has led to a macrolide renaissance, increasing the hope for novel and safe therapeutic agents to combat serious human infectious diseases.

The use of statins alone, or in combination with pioglitazone and other drugs, for the treatment of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and related cardiovascular risk. An Expert Panel Statement.

Abstract: Non-alcoholic fatty liver disease (NAFLD), the most common liver disease, is characterized by accumulation of fat (>5% of the liver tissue), in the absence of alcohol abuse or other chronic liver diseases. It is closely related to the epidemic of obesity, metabolic syndrome or type 2 diabetes mellitus (T2DM). NAFLD can cause liver inflammation and progress to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis or hepatocellular cancer (HCC). Nevertheless, cardiovascular disease (CVD) is the most common cause of death in NAFLD/NASH patients. Current guidelines suggest the use of pioglitazone both in patients with T2DM and in those without. The use of statins, though considered safe by the guidelines, have very limited use; only 10% in high CVD risk patients are on statins by tertiary centers in the US. There are data from several animal studies, 5 post hoc analyses of prospective long-term survival studies, and 5 rather small biopsy proven NASH studies, one at baseline and on at the end of the study. All these studies provide data for biochemical and histological improvement of NAFLD/NASH with statins and in the clinical studies large reductions in CVD events in comparison with those also on statins and normal liver. Ezetimibe was also reported to improve NAFLD. Drugs currently in clinical trials seem to have potential for slowing down the evolution of NAFLD and for reducing liver- and CVD-related morbidity and mortality, but it will take time before they are ready to be used in everyday clinical practice. The suggestion of this Expert Panel is that, pending forthcoming randomized clinical trials, physicians should consider using a PPARgamma agonist, such as pioglitazone, or, statin use in those with NAFLD/NASH at high CVD or HCC risk, alone and/or preferably in combination with each other or with ezetimibe, for the primary or secondary prevention of CVD, and the avoidance of cirrhosis, liver transplantation or HCC, bearing in mind that CVD is the main cause of death in NAFLD/NASH patients.

Experimental investigation of tensile and bond properties of Carbon-FRCM composites for strengthening masonry elements

Abstract: Fabric Reinforced Cementitious Matrix (FRCM) materials are composed of a dry fiber grid embedded in an inorganic matrix, which may contain short fibers. These materials are particularly well-suited for the reinforcement of masonry structures due to their high compatibility with the substrate, vapor permeability and durability against environmental agents. The most important information needed for the characterization of these composite systems, for use as strengthening materials of masonry structures, are the tensile behaviour and the shear bond properties. A Round-Robin Test was organized by the RILEM Technical Committee 250-CSM and the Italian association Assocompositi in order to experimentally characterize different FRCM systems composed of PBO, carbon, glass, basalt, aramid and steel textiles embedded in cementitious or lime-based mortars. The systems were tested at different universities and research centers in Europe in order to investigate the influence of samples preparation, test set-up and instrumentation. In this paper, the experimental tests performed on Carbon-FRCM systems are described and discussed. Important aspects are analyzed herein: differences in the testing procedure and instrumentation, influence of textile geometry and mechanical properties of the constituent materials, importance of specimen preparation and curing conditions. Moreover, a comparison between tensile and shear tests is reported in order to determine a reliable procedure towards the complete characterization of an FRCM material.

On a human-robot collaboration in an assembly cell

Abstract: This is a study of a Human-Robot Collaboration HRC framework for the execution of collaborative tasks in hybrid assembly cells. Robots and humans coexist in the same cell and share tasks according to their capabilities. An intelligent decision-making method that allows human-robot task allocation is proposed and is integrated within a Robot Operating System ROS framework. The proposed method enables the allocation of sequential tasks assigned to a robot and a human in separate workspaces. The focus is rather given to the human–robot coexistence for the execution of sequential tasks, in order for the automation level in manual or even hybrid assembly lines to be increased. Body gestures are the means of a human’s interaction with a robot for commanding and guiding reasons. The proposed framework is implemented into a case coming from the manual assembly lines of an automotive industry. A preliminary design of a hybrid assembly cell is presented, focusing on the assembly of a hydraulic pump by robots and humans.

Ibrutinib for patients with rituximab-refractory Waldenström's macroglobulinaemia (iNNOVATE): an open-label substudy of an international, multicentre, phase 3 trial

Abstract: Summary Background In the era of widespread rituximab use for Waldenstrom's macroglobulinaemia, new treatment options for patients with rituximab-refractory disease are an important clinical need. Ibrutinib has induced durable responses in previously treated patients with Waldenstrom's macroglobulinaemia. We assessed the efficacy and safety of ibrutinib in a population with rituximab-refractory disease. Methods This multicentre, open-label substudy was done at 19 sites in seven countries in adults aged 18 years and older with confirmed Waldenstrom's macroglobulinaemia, refractory to rituximab and requiring treatment. Disease refractory to the last rituximab-containing therapy was defined as either relapse less than 12 months since last dose of rituximab or failure to achieve at least a minor response. Key exclusion criteria included: CNS involvement, a stroke or intracranial haemorrhage less than 12 months before enrolment, clinically significant cardiovascular disease, hepatitis B or hepatitis C viral infection, and a known bleeding disorder. Patients received oral ibrutinib 420 mg once daily until progression or unacceptable toxicity. The substudy was not prospectively powered for statistical comparisons, and as such, all the analyses are descriptive in nature. This study objectives were the proportion of patients with an overall response, progression-free survival, overall survival, haematological improvement measured by haemoglobin, time to next treatment, and patient-reported outcomes according to the Functional Assessment of Cancer Therapy-Anemia (FACT-An) and the Euro Qol 5 Dimension Questionnaire (EQ-5D-5L). All analyses were per protocol. The study is registered at ClinicalTrials.gov, number NCT02165397, and follow-up is ongoing but enrolment is complete. Findings Between Aug 18, 2014, and Feb 18, 2015, 31 patients were enrolled. Median age was 67 years (IQR 58–74); 13 (42%) of 31 patients had high-risk disease per the International Prognostic Scoring System Waldenstrom Macroglobulinaemia, median number of previous therapies was four (IQR 2–6), and all were rituximab-refractory. At a median follow-up of 18·1 months (IQR 17·5–18·9), the proportion of patients with an overall response was 28 [90%] of 31 (22 [71%] of patients had a major response), the estimated 18 month progression-free survival rate was 86% (95% CI 66–94), and the estimated 18 month overall survival rate was 97% (95% CI 79–100). Baseline median haemoglobin of 10·3 g/dL (IQR 9·3–11·7) increased to 11·4 g/dL (10·9–12·4) after 4 weeks of ibrutinib treatment and reached 12·7 g/dL (11·8–13·4) at week 49. A clinically meaningful improvement from baseline in FACT-An score, anaemia subscale score, and the EQ-5D-5L were reported at all post-baseline visits. Time to next treatment will be presented at a later date. Common grade 3 or worse adverse events included neutropenia in four patients (13%), hypertension in three patients (10%), and anaemia, thrombocytopenia, and diarrhoea in two patients each (6%). Serious adverse events occurred in ten patients (32%) and were most often infections. Five (16%) patients discontinued ibrutinib: three due to progression and two due to adverse events, while the remaining 26 [84%] of patients are continuing ibrutinib at the time of this report. Interpretation The sustained responses and median progression-free survival time, combined with a manageable toxicity profile observed with single-agent ibrutinib indicate that this chemotherapy-free approach is a potential new treatment choice for patients who had heavily pretreated, rituximab-refractory Waldenstrom's macroglobulinaemia. Funding Pharmacyclics LLC, an AbbVie Company.

Multiple Sclerosis: Immunopathology and Treatment Update

Abstract: The treatment of multiple sclerosis (MS) has changed over the last 20 years. All immunotherapeutic drugs target relapsing remitting MS (RRMS) and it still remains a medical challenge in MS to develop a treatment for progressive forms. The most common injectable disease-modifying therapies in RRMS include β-interferons 1a or 1b and glatiramer acetate. However, one of the major challenges of injectable disease-modifying therapies has been poor treatment adherence with approximately 50% of patients discontinuing the therapy within the first year. Herein, we go back to the basics to understand the immunopathophysiology of MS to gain insights in the development of new improved drug treatments. We present current disease-modifying therapies (interferons, glatiramer acetate, dimethyl fumarate, teriflunomide, fingolimod, mitoxantrone), humanized monoclonal antibodies (natalizumab, ofatumumb, ocrelizumab, alentuzumab, daclizumab) and emerging immune modulating approaches (stem cells, DNA vaccines, nanoparticles, altered peptide ligands) for the treatment of MS.

Syndecans – key regulators of cell signaling and biological functions

Abstract: Syndecans are a small family of four transmembrane proteoglycans in mammals They have similar structural organization, consisting of an N-terminal ectodomain, single transmembrane domain and C-terminal cytoplasmic domain Over the years, the association between syndecans and the actin cytoskeleton has been established, which has consequences for the regulation of cell adhesion and migration Specifically, ecto- and cytoplasmic domains are responsible for the interaction with extracellular matrix molecules and intracellular kinases, respectively These interactions indicate syndecans as key molecules during cancer initiation and progression Particularly syndecans interact with other cell surface receptors, such as growth factor receptors and integrins, which lead to activation of downstream signaling pathways, which are critical for the cellular behavior Moreover, this review describes the key role of syndecans in intracellular calcium regulation and homeostasis The syndecan-mediated regulation of calcium metabolism is highly correlated with cells' adhesion phenotype through the actin cytoskeleton and formation of junctions, with implications during differentiation and disease progression

Standardized Nanomechanical Atomic Force Microscopy Procedure (SNAP) for Measuring Soft and Biological Samples.

Abstract: We present a procedure that allows a reliable determination of the elastic (Young's) modulus of soft samples, including living cells, by atomic force microscopy (AFM). The standardized nanomechanical AFM procedure (SNAP) ensures the precise adjustment of the AFM optical lever system, a prerequisite for all kinds of force spectroscopy methods, to obtain reliable values independent of the instrument, laboratory and operator. Measurements of soft hydrogel samples with a well-defined elastic modulus using different AFMs revealed that the uncertainties in the determination of the deflection sensitivity and subsequently cantilever's spring constant were the main sources of error. SNAP eliminates those errors by calculating the correct deflection sensitivity based on spring constants determined with a vibrometer. The procedure was validated within a large network of European laboratories by measuring the elastic properties of gels and living cells, showing that its application reduces the variability in elastic moduli of hydrogels down to 1%, and increased the consistency of living cells elasticity measurements by a factor of two. The high reproducibility of elasticity measurements provided by SNAP could improve significantly the applicability of cell mechanics as a quantitative marker to discriminate between cell types and conditions.

Tension and constraints on modified gravity parametrizations of $G_{\textrm{eff}}(z)$ from growth rate and Planck data

Abstract: We construct an updated and extended compilation of growth-rate data based on recent redshift-space distortion measurements. The data set consists of 34 data points and includes corrections for model dependence. In order to minimize overlap and maximize the independence of the data points, we also construct a subsample of this compilation (a ``gold'' growth data set) which consists of 18 data points. We test the consistency of this data set with the best-fit $\mathrm{Planck}15/\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ parameters in the context of General Relativity using the evolution equation for the growth factor $\ensuremath{\delta}(a)$ with a $w\mathrm{CDM}$ background. We find tension at the $\ensuremath{\sim}3\ensuremath{\sigma}$ level between the best-fit parameters $w$ (the dark energy equation of state), ${\mathrm{\ensuremath{\Omega}}}_{0m}$ (the matter density parameter), and ${\ensuremath{\sigma}}_{8}$ (the matter power spectrum normalization on scales $8{h}^{\ensuremath{-}1}\text{ }\text{ }\mathrm{Mpc}$) and the corresponding $\mathrm{Planck}15/\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ parameters ($w=\ensuremath{-}1$, ${\mathrm{\ensuremath{\Omega}}}_{0m}=0.315$, and ${\ensuremath{\sigma}}_{8}=0.831$). We show that the tension disappears if we allow for evolution of the effective Newton constant, parametrized as ${G}_{\mathrm{eff}}(a)/{G}_{\mathrm{N}}=1+{g}_{a}(1\ensuremath{-}a{)}^{n}\ensuremath{-}{g}_{a}(1\ensuremath{-}a{)}^{2n}$ with $n\ensuremath{\ge}2$ where ${g}_{a}$ and $n$ are parameters of the model, $a$ is the scale factor, and $z=1/a\ensuremath{-}1$ is the redshift. This parametrization satisfies three important criteria: a) positive energy of the graviton (${G}_{\mathrm{eff}}g0$), b) consistency with big bang nucleosynthesis constraints (${G}_{\mathrm{eff}}(a\ensuremath{\ll}1)/{G}_{\mathrm{N}}=1$), and c) consistency with Solar System tests (${G}_{\mathrm{eff}}(a=1)/{G}_{\mathrm{N}}=1$ and ${G}_{\mathrm{eff}}^{\ensuremath{'}}(a=1)/{G}_{\mathrm{N}}=0$). We show that the best-fit form of ${G}_{\mathrm{eff}}(z)$ obtained from the growth data corresponds to weakening gravity at recent redshifts (decreasing function of $z$), and we demonstrate that this behavior is not consistent with any scalar-tensor Lagrangian with a real scalar field. Finally, we use MGCAMB to find the best-fit ${G}_{\mathrm{eff}}(z)$ obtained from the Planck cosmic microwave background power spectrum on large angular scales and show that it is a mildly increasing function of $z$, in $3\ensuremath{\sigma}$ tension with the corresponding decreasing best-fit ${G}_{\mathrm{eff}}(z)$ obtained from the growth data.

Glass fabric reinforced cementitious matrix: Tensile properties and bond performance on masonry substrate

Abstract: Fibre-reinforced composite materials have gained an increasing success, mostly for strengthening, retrofitting, and repairing existing structures. However some problems may arise with the use of traditional FRP (Fiber Reinforced Polymer), particularly when the compatibility with the substrate and the reversibility of the intervention are required, as in case of cultural heritage buildings, or specific exposition conditions may compromise the long term effectiveness of the reinforcement, as in presence of high temperature and humidity. Starting from these considerations new composite materials are emerging as a more effective solution in certain fields of application and under specific service conditions; in this context, mortar-based composite systems, consisting of one or more layers of uni- or bi-directional fibre nets embedded in cement/lime-based matrix layers, can be used as reinforcement of both concrete and masonry structures. However, the research work dealing with these emerging materials and their performances when used as a strengthening system for existing structures is still limited. Both experimental and theoretical investigations are needed in order to deliver reliable design methodologies. In this work, a Round Robin Test aimed to the characterization of both bond with the existing substrate and tensile performance of glass fabric (in the form of grids) coupled with inorganic mortar matrices is presented. The investigation was conducted at fifteen laboratories involved in the RILEM Technical Committee 250-CSM (Composites for the Sustainable Strengthening of Masonry). With the aim of studying the bond behaviour between Fabric Reinforced Cementitious Matrix (FRCM) composites and masonry substrate, single and double lap shear tests were carried out on brick-masonry prisms. Results provide useful informations about the mechanical properties, the bond capacity and the failure mechanisms of different commercially available glass FRCM systems. Finally, critical aspects are underlined to address the progress of the research work.

Protein bio-corona: critical issue in immune nanotoxicology

Abstract: With the expansion of the nanomedicine field, the knowledge focusing on the behavior of nanoparticles in the biological milieu has rapidly escalated. Upon introduction to a complex biological system, nanomaterials dynamically interact with all the encountered biomolecules and form the protein "bio-corona." The decoration with these surface biomolecules endows nanoparticles with new properties. The present review will address updates of the protein bio-corona characteristics as influenced by nanoparticle's physicochemical properties and by the particularities of the encountered biological milieu. Undeniably, bio-corona generation influences the efficacy of the nanodrug and guides the actions of innate and adaptive immunity. Exploiting the dynamic process of protein bio-corona development in combination with the new engineered horizons of drugs linked to nanoparticles could lead to innovative functional nanotherapies. Therefore, bio-medical nanotechnologies should focus on the interactions of nanoparticles with the immune system for both safety and efficacy reasons.

Future of robotic surgery in urology.

Abstract: Objectives To provide a comprehensive overview of the current status of the field of robotic systems for urological surgery and discuss future perspectives. Materials and Methods A non-systematic literature review was performed using PubMed/Medline search electronic engines. Existing patents for robotic devices were researched using the Google search engine. Findings were also critically analysed taking into account the personal experience of the authors. Results The relevant patents for the first generation of the da Vinci platform will expire in 2019. New robotic systems are coming onto the stage. These can be classified according to type of console, arrangement of robotic arms, handles and instruments, and other specific features (haptic feedback, eye-tracking). The Telelap ALF-X robot uses an open console with eye-tracking, laparoscopy-like handles with haptic feedback, and arms mounted on separate carts; first clinical trials with this system were reported in 2016. The Medtronic robot provides an open console using three-dimensional high-definition video technology and three arms. The Avatera robot features a closed console with microscope-like oculars, four arms arranged on one cart, and 5-mm instruments with six degrees of freedom. The REVO-I consists of an open console and a four-arm arrangement on one cart; the first experiments with this system were published in 2016. Medicaroid uses a semi-open console and three robot arms attached to the operating table. Clinical trials of the SP 1098-platform using the da Vinci Xi for console-based single-port surgery were reported in 2015. The SPORT robot has been tested in animal experiments for single-port surgery. The SurgiBot represents a bedside solution for single-port surgery providing flexible tube-guided instruments. The Avicenna Roboflex has been developed for robotic flexible ureteroscopy, with promising early clinical results. Conclusions Several console-based robots for laparoscopic multi- and single-port surgery are expected to come to market within the next 5 years. Future developments in the field of robotic surgery are likely to focus on the specific features of robotic arms, instruments, console, and video technology. The high technical standards of four da Vinci generations have set a high bar for upcoming devices. Ultimately, the implementation of these upcoming systems will depend on their clinical applicability and costs. How these technical developments will facilitate surgery and whether their use will translate into better outcomes for our patients remains to be determined.

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

Abstract: The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Performance assessment of basalt FRCM for retrofit applications on masonry

Abstract: An increasing interest and application is nowadays found for composite systems in construction and rehabilitation industry. The consensus on fibre reinforced composite systems was mainly based on high tensile strength, light weight, relative ease of installation, and resistance to corrosion. However, some drawbacks related to the epoxy (hence, organic) matrices of Fiber-Reinforced Polymers (FRP) have been solved by inorganic ones yielding to novel fibre reinforced composites. In these materials the composite action is mainly achieved through mechanical interlock between the matrix (e.g. a cement- or a lime-based mortar or a geopolymer with the option of chopped fibres and/or low-content polymer addition) and the mesh-like fibrous structure (a textile) that allows the mortar to protrude through the grid's openings. Aiming at the investigation of the mechanical properties and the development of testing procedures for this new family of materials (termed herein as Fabric-Reinforced Cementitious Matrix (FRCM)) the present paper presents the results of an extensive experimental program on different combinations of basalt fibre textiles and inorganic matrices organized by RILEM TC 250-CSM (Composites for the Sustainable strengthening of Masonry) involving ten European laboratories. The tests involve more than 100 specimens: half are tensile tests and the other half are bond tests carried out on prisms made of clay bricks, on three different basalt-based FRCM configurations comprising readily available commercial systems provided by different producers. The scope of this work is aimed not only at presenting a comparative performance assessment of different Basalt FRCM systems, but also at providing meaningful criteria to reliably design and analyse retrofit applications. The relevant round robin test program provides valuable data generated during the experimental activity and statistical analysis thereof; then, based on the various testing approaches employed, the advantages/drawbacks of certain testing factors are summarized and critically assessed, reflecting the experience of involved institutions. It is believed that this represents a crucial step in improving knowledge on innovative retrofit applications and developing standard test methods.

Search for invisible decays of sub-GeV dark photons in missing-energy events at the CERN SPS

Abstract: We report on a direct search for sub-GeV dark photons (A^{'}), which might be produced in the reaction e^{-}Z→e^{-}ZA^{'} via kinetic mixing with photons by 100 GeV electrons incident on an active target in the NA64 experiment at the CERN SPS. The dark photons would decay invisibly into dark matter particles resulting in events with large missing energy. No evidence for such decays was found with 2.75×10^{9} electrons on target. We set new limits on the γ-A^{'} mixing strength and exclude the invisible A^{'} with a mass ≲100 MeV as an explanation of the muon g_{μ}-2 anomaly.