1,985 research outputs found
Enhanced propagation of motile bacteria on surfaces due to forward scattering
How motile bacteria move near a surface is a problem of fundamental
biophysical interest and is key to the emergence of several phenomena of
biological, ecological and medical relevance, including biofilm formation.
Solid boundaries can strongly influence a cell's propulsion mechanism, thus
leading many flagellated bacteria to describe long circular trajectories stably
entrapped by the surface. Experimental studies on near-surface bacterial
motility have, however, neglected the fact that real environments have typical
microstructures varying on the scale of the cells' motion. Here, we show that
micro-obstacles influence the propagation of peritrichously flagellated
bacteria on a flat surface in a non-monotonic way. Instead of hindering it, an
optimal, relatively low obstacle density can significantly enhance cells'
propagation on surfaces due to individual forward-scattering events. This
finding provides insight on the emerging dynamics of chiral active matter in
complex environments and inspires possible routes to control microbial ecology
in natural habitats
Comparison of alternative models to predict lean meat percentage of lamb carcasses
The objective of this study was to develop and
compare alternative prediction equations of lean meat proportion
(LMP) of lamb carcasses. Forty (40) male lambs, 22 of Churra
Galega Bragançana Portuguese local breed and 18 of Suffolk breed
were used. Lambs were slaughtered, and carcasses weighed
approximately 30 min later in order to obtain hot carcass weight
(HCW). After cooling at 4º C for 24-h a set of seventeen carcass
measurements was recorded. The left side of carcasses was dissected
into muscle, subcutaneous fat, inter-muscular fat, bone, and
remainder (major blood vessels, ligaments, tendons, and thick
connective tissue sheets associated with muscles), and the LMP was
evaluated as the dissected muscle percentage. Prediction equations of
LMP were developed, and fitting quality was evaluated through the
coefficient of determination of estimation (R2
e) and standard error of
estimate (SEE). Models validation was performed by k-fold
crossvalidation and the coefficient of determination of prediction
(R2
p) and standard error of prediction (SEP) were computed. The
BT2 measurement was the best single predictor and accounted for
37.8% of the LMP variation with a SEP of 2.30%. The prediction of
LMP of lamb carcasses can be based simple models, using as
predictors the HCW and one fat thickness measurement
Optic disc detection by earth mover's distance template matching
This paper presents a method for the detection of OD in the retina which takes advantage of the powerful preprocessing techniques such as the contrast enhancement, Gabor wavelet transform for vessel segmentation, mathematical morphology and Earth Mover’s distance (EMD) as the matching process. The OD detection algorithm is based on matching the expected directional pattern of the retinal blood vessels. Vessel segmentation method produces segmentations by classifying each image pixel as vessel or nonvessel, based on the pixel’s feature vector. Feature vectors are composed of the pixel’s intensity and 2D Gabor wavelet transform responses taken at multiple scales. A simple matched filter is proposed to roughly match the direction of the vessels at the OD vicinity using the EMD. The minimum distance provides an estimate of the OD center coordinates. The method’s performance is evaluated on publicly available DRIVE and STARE databases. On the DRIVE database the OD center was detected correctly in all of the 40 images (100%) and on the STARE database the OD was detected correctly in 76 out of the 81 images, even in rather difficult pathological situations
E-waste Management in Portugal: Legislation, Practices and Recommendations
The use of electrical and electronic devices has grown exponentially in the last years thanks to technological advances and its wide dissemination. Consequently, the number of obsolete equipment (electronic waste or e-waste) has also increased significantly, becoming a major problem for society. This paper deals with electronic waste and explains the concept and risks for the particular case of Portugal. Measures to reduce the problem such as legislation, education production R&D and social responsibility are also discussed. And finally, a survey is presented which was carried out in two Portuguese Higher Education institutions with a view to determining students' awareness, attitudes and opinions on this matter.info:eu-repo/semantics/publishedVersio
Formulación de estrategias de marketing mix a partir del estudio del comportamiento del consumidor de leche en la ciudad de Riobamba/Formulation of marketing mix strategies based on the study of milk consumer behavior in the city of Riobamba
El estudio económico de la conducta del consumidor supone teorías de enfoque positivista y normativo. En este contexto las decisiones de consumo se basan no siempre en un modelo racional, considerando además factores de tipo emocional, experiencias que determinan la decisión de compra. El objetivo de este artículo fue formular estrategias de marketing mix a partir del estudio del comportamiento del consumidor de leche en la ciudad de Riobamba. La metodología utilizada se fundamentó en un estudio cuasi experimental que tomó como base un modelo predeterminado que sirvió para diseñar una encuesta que permitiese identificar y evaluar variables determinantes en la conducta de los consumidores. La investigación permitió determinar las preferencias de marcas de leche, nivel de aceptación del precio, tipo de empaque, medios de comunicación y frecuencia de consumo. Los resultados de la investigación permitieron formular estrategias que contribuyen a incentivar el consumo de leche en la población local.
The economic study of consumer behavior supposes theories of positivist and normative approach. In this context, consumer decisions are not always based on a rational model, considering factors of an emotional nature, experiences that determine the purchase decision. The objective of this article was to formulate marketing mix strategies based on the study of milk consumer behavior in the city of Riobamba. The methodology used was based on a quasi-experimental study that took as a basis a predetermined model that served to design a survey that would identify and evaluate determinant variables in the behavior of consumers. The investigation allowed to determine the preferences of milk brands, level of acceptance of the price, type of packaging, means of communication and frequency of consumption. The results of the research allowed to formulate strategies that contribute to encourage the consumption of milk in the local population.
Palabras clave: comportamiento del consumidor, neuroeconomía, marketing mix.
Keywords: consumer behavior, neuroeconomics, marketing mix
Major challenges in Rheumatology: will we ever treat smarter, instead of just harder?
Copyright © 2019 Romão and Fonseca. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The field of rheumatology has witnessed astonishing progress in the understanding and management of rheumatic diseases since the second half of the twentieth century. The discovery and introduction of glucocorticoids and conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) into the therapeutic armamentarium of rheumatologists enabled, for the first time, to effectively change the natural course of disease and improve most clinical outcomes. The new millennium pushed the revolution further at an exponential level with the advent of sophisticated, biologically-engineered drugs—the so-called biologicals or bDMARDs—that targeted specific molecules in key pathogenic pathways and dramatically modified the prognosis of most patients with immune-mediated rheumatic diseases.VR's work was partially supported by Fundação para a Ciência e Tecnologia (Interno Doutorando Bursary reference SFRH/SINTD/95030/2013).info:eu-repo/semantics/publishedVersio
Disease mechanisms in preclinical rheumatoid arthritis: a narrative review
Copyright © 2022 Romão and Fonseca. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.In the last decades, the concept of preclinical rheumatoid arthritis (RA) has become established. In fact, the discovery that disease mechanisms start years before the onset of clinical RA has been one of the major recent insights in the understanding of RA pathogenesis. In accordance with the complex nature of the disease, preclinical events extend over several sequential phases. In a genetically predisposed host, environmental factors will further increase susceptibility for incident RA. In the initial steps of preclinical disease, immune disturbance mechanisms take place outside the joint compartment, namely in mucosal surfaces, such as the lung, gums or gut. Herein, the persistent immunologic response to altered antigens will lead to breach of tolerance and trigger autoimmunity. In a second phase, the immune response matures and is amplified at a systemic level, with epitope spreading and widening of the autoantibody repertoire. Finally, the synovial and bone compartment are targeted by specific autoantibodies against modified antigens, initiating a local inflammatory response that will eventually culminate in clinically evident synovitis. In this review, we discuss the elaborate disease mechanisms in place during preclinical RA, providing a broad perspective in the light of current evidence.VCR work was funded by Fundação para a Ciência e Tecnologia (Interno Doutorando Bursary reference SFRH/SINTD/95030/2013); European League Against Rheumatism (EULAR Scientific Training Bursary 2014); and Sociedade Portuguesa de Reumatologia (Fundo de Apoio à Investigação da SPR 2015 & 2016 to VCR).info:eu-repo/semantics/publishedVersio
Cattle identification based in biometric features of the muzzle
Cattle identification has been a serious issue for breeding association. The muzzle pattern that is correlated with human fingerprints has been considered as a biometric marker for cattle and could be used in identification of bovine animals.
This work presents a robust and fast cattle identification scheme from muzzle images using Speed-up Robust Features matching. To eliminate miss-matched outliers a matching refinement technique based on the matching orientation information has been proposedinfo:eu-repo/semantics/publishedVersio
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