327 research outputs found

    Discovering ethnic minority business research directions using text mining and topic modelling

    Get PDF
    Moro, S., Pires, G., Rita, P., Cortez, P., & Ramos, R. F. (2022). Discovering ethnic minority business research directions using text mining and topic modelling. Journal of Research in Marketing and Entrepreneurship. https://doi.org/10.1108/JRME-01-2022-0004Abstract Purpose This study aims to unveil within the current academic literature the principal directions in the ethnic entrepreneurship and small business marketing research context. Design/methodology/approach An automated literature analysis procedure was undertaken, attempting to cover all literature published on the subject since 1962. A total of 188 articles were analysed using text mining and topic modelling. Findings The results show a lack of framing of ethnic entrepreneurship literature outside the narrower scope of migration. Some core themes were found (e.g. network, diversity) around which several other themes orbit, including both related issues to the ethnic factor (e.g. barriers and minorities) and managerial issues (e.g. marketing and production). Originality/value Ethnic minority business and small business marketing research has seen a growing number of publications. However, a careful review of existing work is missing.authorsversionepub_ahead_of_prin

    Electrocardiography in hypertensive patients without cardiovascular events: a valuable predictor tool?

    Get PDF
    Background. Hypertension is an important risk factor of cardiovascular (CV) disease. An early diagnosis of target organ damage could prevent major CV events. Electrocardiography (ECG) is a valuable clinical technique, with wide availability and high speci city, used in evaluation of hypertensive patients. However, the use of ECG as a predictor tool is controversial given its low sensitivity. is study aims to characterise ECG features in a hypertensive population and identify ECG abnormalities that could predict CV events. Methods. We studied 175 hypertensive patients without previous CV events during a follow-up mean of 4.0 ± 2.20 years. ECGs and pulse wave velocity were performed in all patients. Clinical characteristics and ECG abnormalities were evaluated and compared between the patients as they presented CV events. Results. Considering the 175 patients (53.14% male), the median age was 62 years. Median systolic blood pressure was 140 mmHg and diastolic blood pressure was 78 mmHg. Median PWV was 9.8 m/s. Of the patients, 39.4% were diabetic, 78.3% had hyperlipidaemia, and 16.0% had smoking habits. ECG identi ed left ventricular (LV) hypertrophy in 29.71% of the patients, and a LV strain pattern was present in 9.7% of the patients. Twenty-nine patients (16.57%) had a CV event. Comparative analyses showed statistical signi cance for the presence of a LV strain pattern in patients with CV events (p 0.01). Univariate and multivariate analysis con rmed that a LV strain pattern was an independent predictor of CV event (HR 2.66, 95% IC 1.01–7.00). In the survival analysis, the Kaplan–Meier curve showed a worse prognosis for CV events in patients with a LV strain pattern (p 0.014). Conclusion. ECG is a useful daily method to identify end-organ damage in hypertensive patients. In our study, we also observed that it may be a valuable tool for the prediction of CV events.publishe

    Ambiente construído e mobilidade em cidades de média dimensão

    Get PDF
    A relação entre as características do ambiente construído e a mobilidade dos habitantes tem sido amplamente estudada. No entanto, a maioria desta investigação tem-se debruçado sobre contextos metropolitanos, e pouco se sabe sobre esta relação nas cidades de média dimensão, as quais possuem características de mobilidade muito próprias. Por um lado, a sua dimensão reduzida permite que grande parte das deslocações possa ser realizada a pé, mas por outro, o reduzido nível de tráfego e a fraca oferta de transportes públicos promovem as deslocações em veículo individual. Este artigo foca-se na relação entre características do ambiente construído e a mobilidade da população no contexto de cidades médias portuguesas, designadamente Castelo Branco, Faro, Santarém e Vila Real. Os dados resultam de um inquérito à mobilidade nas 4 cidades, com cerca de 4500 indivíduos, e de cálculos de indicadores para descrever as características do ambiente construído, designadamente a densidade, diversidade, design e acessibilidade. Os resultados das análises estatísticas reforçam a importância do ambiente construído como estímulo para uma mobilidade urbana mais sustentável.info:eu-repo/semantics/publishedVersio

    Acoustic determination of thermophysical properties and critical parameters for R404A and critical line of x CO2+(1− x) R404A

    Get PDF
    The thermophysical properties and critical parameters for the alternative refrigerant R404A (52 wt % of 1,1,1- trifluoroethane (R143a) + 44 wt % of pentafluoroethane (R125) + 4 wt % of 1,1,1,2-tetrafluoroethane (R134a)) were investigated using two different acoustic techniques. The critical behavior of the system xCO2 + (1 - x)R404A was also investigated. Experimental data of speed of sound in liquid R404A from 258 K to 338 K and pressures up to 65 MPa were measured using a pulse-echo method. Derived thermodynamic properties are calculated, combining our experimental data with density and isobaric heat capacity values published by other authors. Measurements of the critical temperature Tc and pressure pc on (R404A) and mixtures of xCO2 + (1 - x)R404A were performed using another simple ultrasonic time-delay technique. The binary critical line was determined over the whole composition range showing that this system deviates only slightly from ideality since the critical line is a continuous line. The Peng-Robinson equation of state with conventional mixing and combining rules was used to correlate the binary experimental data.info:eu-repo/semantics/publishedVersio

    Acoustic determination of thermophysical properties and critical parameters for R410A and critical line of x CO2+(1− x) R410A

    Get PDF
    The thermophysical properties and critical parameters for the alternative refrigerant R410A (a near azeotropic refrigerant mixture containing difluoromethane (R32) and pentafluoroethane (R125) (50 wt % of each)) were investigated using two different acoustic techniques. The critical behavior of the system xCO2 + (1 - x)R410A was also investigated. Experimental data of speed of sound in liquid R410A from (253 to 338) K and pressures up to 65 MPa were measured using a pulse-echo method. Derived thermodynamic properties were calculated, combining our experimental data with density and isobaric heat capacity values published by other authors. Measurements of the critical temperature Tc and pressure pc on (R410A) and mixtures of xCO2 + (1 - x)R410A were performed using another simple ultrasonic time-delay technique. The binary critical line was determined over the whole composition range, showing that this system deviates only slightly from ideality since the critical line is a continuous line. The Peng-Robinson equation of state with conventional mixing and combining rules was used to correlate the binary experimental data.info:eu-repo/semantics/publishedVersio

    Double-layer force suppression between charged microspheres

    Get PDF
    In this paper we propose a protocol to suppress double-layer forces between two microspheres immersed in a dielectric medium, being one microsphere metallic at a controlled potential ψ M and the other a charged one either metallic or dielectric. The approach is valid for a wide range of distances between them. We show that, for a given distance between the two microspheres, the double-layer force can be totally suppressed by simply tuning ψ M up to values dictated by the linearized Poisson-Boltzmann equation. Our key finding is that such values can be substantially different from the ones predicted by the commonly used proximity force approximation, also known as the Derjaguin approximation, even in situations where the latter is expected to be accurate. The proposed procedure can be used to suppress the double-layer interaction in force spectroscopy experiments, thus paving the way for measurements of other surface interactions, such as Casimir dispersion forces

    A Contribution to the Bio and Circular Economy

    Get PDF
    and Cássia H. Barbosa’s Ph.D. fellowship (2021.08154.BD). MMA thanks the Instituto Superior Técnico for the Scientific Employment contract (contract No: IST-ID/154/2018) under Decree-Law No. 57/2016 and 57/2017. Publisher Copyright: © 2023 by the authors.The development of innovative/sustainable materials capable of enlarging the shelf-life of food products has lately been a focus of research, aiming to reduce food waste. Due to their good antimicrobial properties, zinc oxide nanoparticles (ZnO NPs) can add activity to food packaging, improving its performance. Furthermore, these nanoparticles are considered GRAS by the Food and Drug Administration (FDA), which represents an advantage in their application. Through an innovative and sustainable approach using tomato and passionfruit extracts, ZnO NPs were produced and incorporated into pectin films. The resulting bionanocomposites were tested for their activity via in situ studies, using fresh poultry meat as a food matrix. Overall, the bionanocomposites presented good antimicrobial activity, with the intrinsic antimicrobial properties of pectin having shown to be enhanced by the incorporated ZnO NPs. When used as primary packaging for the meat, the deterioration rate of the poultry meat, measured through microbiological growth and total volatile basic nitrogen content, was reduced. However, the nanoparticles contributed to the increment of discoloration and meat oxidation processes. Nonetheless, it can be concluded that fresh poultry meat protected with the bionanocomposites presented an extension of its shelf-life time, and it was confirmed that this eco-friendly packaging has potential to be employed by the food industry.publishersversionpublishe

    Pelvetia canaliculata as an aquafeed supplement for gilthead seabream Sparus aurata: A biorefinery approach for seaweed biomass valorisation

    Get PDF
    For sustainable and economically viable aquaculture, it is necessary to search for alternative sources of aquafeeds. Algae have been studied because of their bioactive compounds with several activities such as antioxidants. The direct incorporation of the macroalgae Pelvetia canaliculata in sunflower oil to increase oxidative stability and biological value results in waste with high nutritional value that may be used as an ingredient in aquaculture feed. This study aimed to evaluate the effect of incorporating algae powder (PEL 1%, PEL 10%) and algae waste obtained after sunflower oil supplementation (WO 1%, WO 10%) in aquafeeds for gilthead seabream. We studied the growth performance, haematological profile, oxidative stress and metabolic parameters, and intestine histomorphology. Experimental diets did not influence growth performance or somatic indexes, and barely affected the haematological profile. Catalase showed higher activity in seabream fed with PEL10 than with control diet. Total glutathione had a higher activity in fish fed with both WO diets. Plasmatic levels of cholesterol were higher in PEL1 and WO10. Triglyceride levels were higher in WO1 and total lipids were higher in both WO diets. The histomorphology of the intestine was slightly modulated by experimental diets but was not affected negatively. In general, supplementation with Pelvetia powder and algal waste oil may be used as an aquafeed for gilthead seabream according to the results obtained for growth, some haematological parameters, catalase and total glutathione, intestinal villi length, and the number of total and acid goblet cells.info:eu-repo/semantics/publishedVersio
    corecore