122 research outputs found
The impact of media pressure on corporate sustainability in the cement industry : a portuguese case study
In this study we examine the sustainability reporting practices and sustainability strategies of a leading Portuguese cement company. The Portuguese cement industry had to deal since 1997 with scrutiny and pressure because of its involvement in co-incineration of hazardous industrial waste. Grounded on a lens of analysis combining legitimacy theory and media agenda-setting theory and based on a content analysis of sustainability reports and semi-structured interviews, we analyse the strategies used by the company to deal with said scrutiny and pressure and present its sustainability performance. Media pressure does seem to have impacted sustainability reporting and sustainability strategies as tools for the company to restore its legitimacy. Findings generally suggest that strategies of communication designed to legitimate the company actions were used. In particular, we suggest that the company managed its legitimacy by using simultaneously two sustainability reporting strategies: one of image enhancement and other of avoidance of threatening topics.info:eu-repo/semantics/publishedVersio
The impact of media pressure on corporate sustainability in the cement industry: a Portuguese case study
In this study we examine the sustainability reporting practices and sustainability strategies of a leading Portuguese cement company. The Portuguese cement industry had to deal since 1997 with scrutiny and pressure because of its involvement in co-incineration of hazardous industrial waste. Grounded on a lens of analysis combining legitimacy theory and media agenda-setting theory and based on a content analysis of sustainability reports and semi-structured interviews, we analyse the strategies used by the company to deal with said scrutiny and pressure and present its sustainability performance. Media pressure does seem to have impacted sustainability reporting and sustainability strategies as tools for the company to restore its legitimacy. Findings generally suggest that strategies of communication designed to legitimate the company actions were used. In particular, we suggest that the company managed its legitimacy by using simultaneously two sustainability reporting strategies: one of image enhancement and other of avoidance of threatening topics.info:eu-repo/semantics/publishedVersio
Bio-inspired Systems for Carbon Dioxide Capture, Sequestration and Utilization
This chapter reviews the study and development of biological, enzymatic and bio-molecular systems for carbon dioxide capture and further sequestration or even utilization. Regardless of the interest on the use of the captured CO2 as C1 synthon on the manufacture of added-value compounds, there is a tremendous unbalance between the requirements of the contemporary society (leading to a massive production of carbon dioxide) and the framework of commercialization of the products from CO2 utilization. In this context, viable options are storage as a solid in the form of calcium or magnesium carbonate and conversion into other energetic frameworks. In addition, it is important to highlight that the conventional energy resources are progressively being replaced by renewable resources. While the change in energetic paradigm is not accomplished, systems that capture and convert carbon dioxide are highly sought. To this end, bio-inspired systems will be presented, starting from the use of compounds from the chiral pool, such as amino acids, saccharides and related bio-polymers, involved in the physical and chemical capture, sequestration and/or utilization of CO2. Additionally, enzymatic systems are presented in the context of sequestration of CO2 in the form of solid carbonates or even utilization of this C1 synthon in the preparation of fuels and commodity chemicals. Carbonic anhydrase is by far the most studied enzyme, as it catalyses the inter-conversion between CO2 and hydrogencarbonate in an effective mode. The biological option comprises the utilization of methanogens, acetogens and other organisms leading to the formation of added-value compounds. Most of the described systems are based on microbial electro-synthesis model and microbial carbon-capture cell prototypes
Extraction, selection and comparison of features for an effective automated computer-aided diagnosis of Parkinson's disease based on [123I]FP-CIT SPECT images
Purpose This work aimed to assess the potential of a set of features extracted from [I-123] FP-CIT SPECT brain images to be used in the computer-aided "in vivo" confirmation of dopaminergic degeneration and therefore to assist clinical decision to diagnose Parkinson's disease.Methods Seven features were computed from each brain hemisphere: five standard features related to uptake ratios on the striatum and two features related to the estimated volume and length of the striatal region with normal uptake. The features were tested on a dataset of 652 [I-123] FP-CIT SPECT brain images from the Parkinson's Progression Markers Initiative. The discrimination capacities of each feature individually and groups of features were assessed using three different machine learning techniques: support vector machines (SVM), k-nearest neighbors and logistic regression.Results Cross-validation results based on SVM have shown that, individually, the features that generated the highest accuracies were the length of the striatal region (96.5%), the putaminal binding potential (95.4%) and the striatal binding potential (93.9%) with no statistically significant differences among them. The highest classification accuracy was obtained using all features simultaneously (accuracy 97.9%, sensitivity 98% and specificity 97.6%). Generally, slightly better results were obtained using the SVM with no statistically significant difference to the other classifiers for most of the features.Conclusions The length of the striatal region uptake is clinically useful and highly valuable to confirm dopaminergic degeneration "in vivo" as an aid to the diagnosis of Parkinson's disease. It compares fairly well to the standard uptake ratio-based features, reaching, at least, similar accuracies and is easier to obtain automatically. Thus, we propose its day to day clinical use, jointly with the uptake ratio-based features, in the computer-aided diagnosis of dopaminergic degeneration in Parkinson's disease
Prevalence and Predictive Factors of Exclusive Breastfeeding in the First Six Months of Life
info:eu-repo/semantics/publishedVersio
CFRP bioinspirados para melhoria da resistência ao impacto e autossensorização
Os compósitos reforçados com fibras de carbono (CFRP) são cada vez mais usados em aplicações de elevado desempenho devido às excelentes propriedades mecânicas e baixo peso que apresentam. A resistência interlaminar continua, no entanto, a ser uma das maiores limitações do seu desempenho mecânico [1-3].
Recentemente, tem-se vindo a tentar superar o problema aplicando nos CFRP mecanismos semelhantes aos que garantem um elevado desempenho ao impacto em organismos vivos, p.e., o exosqueleto dos artrópodes que apresenta uma estrutura fibrosa laminada helicoidal (Bouligand) à escala micrométrica [4-6]. Sistemas sensoriais estudados em seres vivos também têm inspirado o desenvolvimento de compósitos multifuncionais [7], sendo ainda um desafio a criação de tecnologias de fabrico capazes de replicar estas estruturas/sistemas.
Neste trabalho fabricaram-se CFRPs com desempenho mecânico melhorado, usando laminados bioinspirados com fibras orientadas helicoidalmente (tipo Bouligand) e nanotubos de carbono (CNT) como sensores capazes de lhes conferiram multifuncionalidade (monitorização de dano). Produziram-se por infusão por vácuo, usando uma resina epóxÃda reforçada com fibras contÃnuas de carbono, placas CFRP (550x180x4 mm) com empilhamentos helicoidal e standard que, para comparação de propriedades, foram sujeitas a ensaios de impacto e de compressão após-impacto. Para garantir a multifuncionalidade, transferiram-se florestas de CNT verticalmente alinhados (VA-CNT) obtidas por deposição quÃmica a vapor (CVD) para o laminado. Usaram-se ainda técnicas não-destrutivas (NDT) de ultrassons (C-Scan) na análise da microestrutura e avaliação dos danos produzidos após impacto. Os resultados evidenciam as dificuldades encontradas em fabricar as placas e as melhorias que a integração de estruturas bioinspiradas conferem à s caracterÃsticas e multifuncionalidade dos compósitosProjeto IAMATinfo:eu-repo/semantics/publishedVersio
Fatal cases of Theileria annulata infection in calves in Portugal associated with neoplastic-like lymphoid cell proliferation
The authors describe 15 cases of acute lethal infection of calves (≤ 4 months of age) by the protozoan parasite Theileria annulata in the south of Portugal. Calves developed multifocal to coalescent nodular skin lesions, similar to multicentric malignant lymphoma. Infestation with ticks (genus Hyalomma) was intense. Theileria was seen in blood and lymph node smears, and Theileria annulata infection was confirmed by isolation of schizont-transformed cells and sequencing of hypervariable region 4 of the 18S rRNA gene. At necropsy, hemorrhagic nodules or nodules with a hemorrhagic halo were seen, particularly in the skin, subcutaneous tissue, skeletal and cardiac muscle, pharynx, trachea and intestinal serosa. Histologically nodules were formed by large, round, lymphoblastoid neoplastic-like cells. Immunohistochemistry (IHC) identified these cells as mostly CD3 positive T lymphocytes and MAC387 positive macrophages. A marker for B lymphocytes (CD79αcy) labelled very few cells. Theileria annulata infected cells in these nodules were also identified by IHC, through the use of two monoclonal antibodies (1C7 and 1C12) diagnostic for the parasite. It was concluded that the pathological changes observed in the different organs and tissues were caused by proliferation of schizont-infected macrophages, which subsequently stimulate a severe uncontrolled proliferation of uninfected T lymphocytes
Tuning cathode porosity for electrochemical reduction of CO2 at high pressure [Resumo]
ABSTRACT: The development of active and stable catalytic cathodes is critical for advancing electrochemical carbon dioxide reduction into fuels and chemicals from Lab to market. This is a technology with a high potential to contribute to combat climate changes by using captured CO2, water and renewable energy [1]. The use of
pressures higher than atmospheric pressure to carry out the co-electrolysis of CO2 and water has been
recognized as an important process intensification parameter to increase productivities and energy efficiency
[2]. Ongoing work addresses the preparation of aerogels by the sol gel method and impregnation with zinc
and copper metallic particles to be used as cathodes for the co-electrolysis of CO2 and water to produce
syngas at temperatures near room temperature and high-pressure. Ionic liquid-based electrolytes are used to
increase CO2 concentration at the surface of the electrode and consequently productivities, as some ionic
liquid families are known to solubilize high amounts of CO2. Aerogels have been investigated for many different applications including as catalyst supports, due to their high surface area, stability in gaseous or
liquid phases, and efficient transport through large meso and macropores. The present work reports a strategy
to tune the pore sizes of the catalytic electrodes by the use of reticulating agents and supercritical CO2 drying.
Productivities and faradaic efficiencies of the porous materials with the different reticulating agents are
compared and interpreted in respect to their surface characterization e.g. BET surface areas and
morphologies determined by SEM. The potential of new aerogel-based catalytic cathodes on the efficiency
of the electrochemical CO2 reduction will be discussed and its impact in fostering supercritical fluids
technology through its use in processes for the mitigation of climate changes.N/
An integrated analysis of the eutrophication process in the Enxoé reservoir within the DPSIR framework
The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state
in the country since its early years of operation. The problem has attracted water managers’
and researchers’ attention as the reservoir is the water supply for two municipalities. Extensive
research was thus conducted over the last few years, including field monitoring and modelling
at the plot, catchment, and reservoir scales. This study now frames all partial findings within the
Driver-Pressure-State-Impact-Response (DPSIR) framework to better understand the eutrophication
process in the Enxoé reservoir. Agriculture and grazing were found to have a reduced role in the
eutrophication of the reservoir, with annual sediment and nutrient loads being comparably smaller or
similar to those reported for other Mediterranean catchments. Flash floods were the main mechanism
for transporting particle elements to the reservoir, being in some cases able to carry up three times the
average annual load. However, the main eutrophication mechanisms in the reservoir were P release
from deposited sediment under anoxic conditions and the process of internal recycling of organic
matter and nutrients. Reducing the P load from the catchment and deposited sediment could lead to
a mesotrophic state level in the reservoir. However, this level would only be sustainable by limiting
the P internal load ability to reach the photic zoneinfo:eu-repo/semantics/publishedVersio
Synthesis and biological evaluation of Amphotericin B formulations based on organic salts and ionic liquids against Leishmania infantum
Nowadays, organic salts and ionic liquids (OSILs) containing active pharmaceutical ingredients (APIs) are being explored as drug delivery systems in modern therapies (OSILs-API). In that sense, this work is focused on the development of novel OSILs-API based on amphotericin B through an innovative procedure and the evaluation of the respective biological activity against Leishmania infantum. Several ammonium, methylimidazolium, pyridinium and phosphonium organic cations combined with amphotericin B as anion were synthesized in moderate to high yields and high purities by the water-reduced buffer neutralization method. All prepared compounds were characterized to confirm the desired chemical structure and the specific optical rotation ([α]D25) was also determined. The biological assays performed on L. infantum promastigotes showed increased activity against this parasitic disease when compared with the starting chloride forms and amphotericin B alone, highlighting [P6,6,6,14][AmB] as the most promising formulation. Possible synergism in the antiprotozoal activity was also evaluated for [P6,6,6,14][AmB], since it was proven to be the compound with the highest toxicity. This work reported a simple synthetic method, which can be applied to prepare other organic salts based on molecules containing fragile chemical groups, demonstrating the potential of these OSILs-AmB as possible agents against leishmaniasis.info:eu-repo/semantics/publishedVersio
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