221 research outputs found

    Effects of high-normal and mildly increased arterial blood pressure on right ventricular function: application of new echocardiographic techniques

    Get PDF
    Purpose: To analyze the relationship between increasing systemic blood pressure and right ventricular function by means of Tissue-Doppler Imaging (TDI) and Two-dimesional Strain echocardiographic techniques. Subjects and methods: Ninety-eight never-treated, nonobese patients with blood pressure values varying from the optimal to the mild hypertensive range were recruited. Peak early (Em) and late (Am) diastolic and systolic (Sm) velocities were recorded at the tricuspid and mitral annuli by TDI. Longitudinal peak strain and strain rate (SR) were sampled by speckle-tracking methodology at the right ventricle (RV) free wall and interventricular septum (IVS) and RV and left ventricular (LV) structure and function were evaluated by conventional echo-Doppler sonography. Insulin sensitivity was tested by homeostasis model assessment (HOMA) index. Data were analyzed by 24-h systolic BP (SBP) (cut-offs 117 and 130 mmHg), thus partitioning an optimal BP from an intermediate high-normal and an upper mildly increased BP stratum. Results: Em decreased in the mid-third and decelerated further in association with reduced Sm in the upper BP tertile; both correlated negatively to septal thickness and positively to homologous TDI-derived LV indices. RV peak systolic strain and early diastolic SR decreased in the mid-BP third without further changes in the upper tertile. IVS thickened gradedly by increasing systemic 24-h SBP; posterior wall remodelled to a lesser extent and poorly related to BP load and LV mass index did not change. RV and IVS systolic and diastolic strain indices associated inversely with increasing septal thickness. RV and LV indices of global ventricular function, estimated pulmonary pressure, HOMA did not differ by systemic BP. Conclusion: TDI and 2D-strain echocardiography showed a RV diastolic and systolic function impairment in response to slightly increased systemic BP. The process paralleled homologous changes at the LV side and was driven by interventricular septum remodeling, perhaps as a reflection of its role in RV function and biventricular interdependence. Insulin sensitivity seemed to play no relevant role

    UNIFORM: Automatic Alignment of Open Learning Datasets

    Get PDF
    Learning Analytics aims at supporting the understanding of learning mechanisms and their effects by means of data-driven strategies. LA approaches commonly face two big challenges: first, due to privacy reasons, most of the analyzed data are not in the public domain. Secondly, the open data collections, which come from diverse learning contexts, are quite heterogeneous. Therefore, the research findings are not easily reproducible and the publicly available datasets are often too small to enable further data analytics. To overcome these issues, there is an increasing need for integrating open learning data into unified models. This paper proposes UNIFORM, an open relational database integrating various learning data sources. It presents also a machine learning supported approach to automatically extending the integrated dataset as soon as new data sources become available. The proposed approach exploits a classifier to predict attribute alignments based on the correlations among the corresponding textual attribute descriptions. The integration phase has reached a promising quality level on most of the analyzed benchmark datasets. Furthermore, the usability of the UNIFORM data model has been demonstrated in a real case study, where the integrated data have been exploited to support learners’ outcome prediction. The F1-score achieved on the integrated data is approximately 30% higher than those obtained on the original data

    From teaching books to educational videos and vice versa: a cross-media content retrieval experience

    Get PDF
    Due to the rapid growth of multimedia data and the diffusion of remote and mixed learning, teaching sessions are becoming more and more multi-modal. To deepen the knowledge of specific topics, learners can be interested in retrieving educational videos that complement the textual content of teaching books. However, retrieving educational videos can be particularly challenging when there is a lack of metadata information. To tackle the aforesaid issue, this paper explores the joint use of Deep Learning and Natural Language Processing techniques to retrieve cross-media educational resources (i.e., from text snippets to videos and vice versa). It applies NLP techniques to both the audio transcript of the videos and to the text snippets in the books in order to quantify the semantic relationships between pairs of educational resources of different media types. Then, it trains a Deep Learning model on top of the NLP-based features. The probabilities returned by the Deep Learning model are used to rank the candidate resources based on their relevance to a given query. The results achieved on a real collection of educational multimodal data show that the proposed approach performs better than state-of-the-art solutions. Furthermore, a preliminary attempt to apply the same approach to address a similar retrieval task (i.e., from text to image and vice versa) has shown promising results

    An Overview on Functional Integration of Hybrid Renewable Energy Systems in Multi-Energy Buildings

    Get PDF
    Buildings are responsible for over 30% of global final energy consumption and nearly 40% of total CO2 emissions. Thus, rapid penetration of renewable energy technologies (RETs) in this sector is required. Integration of renewable energy sources (RESs) into residential buildings should not only guarantee an overall neutral energy balance over long term horizon (nZEB concept), but also provide a higher flexibility, a real-time monitoring and a real time interaction with end-users (smart-building concept). Thus, increasing interest is being given to the concepts of Hybrid Renewable Energy Systems (HRES) and Multi-Energy Buildings, in which several renewable and nonrenewable energy systems, the energy networks and the energy demand optimally interact with each other at various levels, exploring all possible interactions between systems and vectors (electricity, heat, cooling, fuels, transport) without them being treated separately. In this context, the present paper gives an overview of functional integration of HRES in Multi-Energy Buildings evidencing the numerous problems and potentialities related to the application of HRESs in the residential building sector. Buildingintegrated HRESs with at least two RESs (i.e., wind–solar, solar–geothermal and solar–biomass) are considered. The most applied HRES solutions in the residential sector are presented, and integration of HRES with thermal and electrical loads in residential buildings connected to external multiple energy grids is investigated. Attention is focused on the potentialities that functional integration can offer in terms of flexibility services to the energy grids. New holistic approaches to the management problems and more complex architectures for the optimal control are described

    Trail View

    Get PDF
    In recent years, the National Park Service has been looking for more ways to incorporate technology into the preservation, research, and enjoyment of nature. Trail View serves as a way to close the gap between humans and nature by offering an interactive virtual tour of Acadia National Park’s hiking trails. Similar to the concept of Google Street View, Trail View is an interconnected series of panoramic photos. It is further expanded into an educational tool by displaying information about natural phenomena alongside the trail. Its intended use is to increase interest in Acadia, educate people on environmental and conservation issues, and create a database of relevant trail information

    An insight into the degradation processes of the anti-hypertensive drug furosemide

    Get PDF
    Furosemide (FUR), an active pharmaceutical ingredient (API) belonging to a group of drugs known as loop diuretics, has widespread use, but, is characterized by a strong instability to light, which causes chemical transformations that could give a yellowing phenomenon and have a significant impact from a health and marketing point of view. Many studies have tried to explain this phenomenon under different experimental conditions, but no detailed explanation of the yellowing phenomenon has been provided. This work, unlike the others, provides an overall view and explanation of the behavior of FUR in relation to the yellowing phenomenon, both in the solution and in solid state, considering several aspects, such as light exposure, presence of oxygen, and moisture effects

    Thermal characterization of recycled materials for building insulation

    Get PDF
    The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy per-formances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(mK), while that of building materials with natural fibers was always lower than 0.162 W/(mK) with lower values for com-pounds with recycled materials (0.107 W/(mK)). Further developments are underway to analyze the mechanical properties of these materials

    Acaricidal activity of bufadienolides Isolated from Drimia pancration against Tetranychus urticae, and structural elucidation of arenobufagin-3-O-α-L-rhamnopyranoside

    Get PDF
    Chemical characterization of the bulbs of Drimia pancration was conducted to isolate four steroidal saponins (1–4). Earlier, we focused on the structural elucidation of compounds 1–3. Herein, by means of 1H-NMR, 13C-NMR, Nuclear Overhauser Effects (NOE), and 2D-NMR spectra, the full stereochemical structure of 4 is reported, and all the 1H and 13C signals are assigned. Com- pounds 1–4 were tested for their acaricidal properties against the two-spotted spider mite Tetranychus urticae. Our results showed excellent activity of compound 1, with an LD50 (μg/cm2) of 0.29 and a LD90 (μg/cm2) of 0.96, whereas compounds 2, 3, and 4 showed moderate activity. Fur- thermore, the acaricidal and cytotoxic properties of the crude extract were also investigated. Of note, after 96 h of exposure, the acaricidal activity of compound 1 was higher than that of the positive control, hexythiazox. Indeed, for compound 1, LD50 and LD90 were 0.29 and 0.96 μg/cm2, respec- tively, while hexythiazox LD50(90) was 18.7 (132.5) μg/cm2. Additionally, D. pancration extract, after 72 h, induced a high cytotoxic effect in HaCaT and THP-1 cell lines, with an IC50 of 7.37 ± 0.5 μg/mL and 3.50 ± 0.15 μg/mL, respectively. Overall, D. pancration can be considered as a green source of novel acaricides effective against mites of agricultural importance, such as T. urticae, pending proper field validation and the assessment of non-target effects on other invertebrate species
    • …
    corecore