An explanation of or-deletions and other paradoxical disjunctive inferences

Some inferences of the sort: A or B; therefore A, which are invalid in standard logics, are sensible in life: You can enter now or later; therefore, you can enter now. That these "or-deletions" follow necessarily or only possibly is a by-product of a theory of mental models. Its semantics for "or" refers to conjunctions of possibilities holding in default of knowledge to the contrary. It predicts new sorts of or-deletion, such as: He likes to drink red wine or white wine. So, he likes to drink red wine. and: You are permitted to do only one of the following: You can enter now. You can enter later. Therefore, you are permitted to enter now. They are invalid in standard logics, and neither previous pragmatic nor semantic theories predicted them. Four experiments corroborated their occurrence.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Three-dimensional culture of single embryonic stem-derived neural/stem progenitor cells in fibrin hydrogels: neuronal network formation and matrix remodelling

In an attempt to improve the efficacy of neural stem/progenitor cell (NSPC) based therapies, fibrin hydrogels are being explored to provide a favourable microenvironment for cell survival and differentiation following transplantation. In the present work, the ability of fibrin to support the survival, proliferation, and neuronal differentiation of NSPCs derived from embryonic stem (ES) cells under monolayer culture was explored. Single mouse ES-NSPCs were cultured within fibrin (fibrinogen concentration: 6 mg/ml) under neuronal differentiation conditions up to 14 days. The ES-NSPCs retained high cell viability and proliferated within small-sized spheroids. Neuronal differentiation was confirmed by an increase in the levels of ßIII-tubulin and NF200 over time. At day 14, cell-matrix constructs mainly comprised NSPCs and neurons (46.5% ßIII-tubulin + cells). Gamma-aminobutyric acid (GABA)ergic and dopaminergic/noradrenergic neurons were also observed, along with a network of synaptic proteins. The ES-NSPCs expressed matriptase and secreted MMP-2/9, with MMP-2 activity increasing along time. Fibronectin, laminin and collagen type IV deposition was also detected. Fibrin gels prepared with higher fibrinogen concentrations (8/10 mg/ml) were less permissive to neurite extension and neuronal differentiation, possibly owing to their smaller pore area and higher rigidity. Overall, it is shown that ES-NSPCs within fibrin are able to establish neuronal networks and to remodel fibrin through MMP secretion and extracellular matrix (ECM) deposition. This three-dimensional (3D) culture system was also shown to support cell viability, neuronal differentiation and ECM deposition of human ES-NSPCs. The settled 3D platform is expected to constitute a valuable tool to develop fibrin-based hydrogels for ES-NSPC delivery into the injured central nervous system.The authors would like to acknowledge Prof. Domingos Henrique (Instituto de Medicina Molecular, Lisbon) for providing the ES 46C cell line. This work was supported by FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE (FCOMP‐01–0124‐FEDER‐021125) and by National funds FCT – Fundação para a Ciência e a Tecnologia (PTDC/SAU‐BMA/118869/2010). A.R.B. and M.J. Oliveira are supported by FCT (SFRH/BD/86200/2012; Investigator FCT)

Optical Flow on Evolving Surfaces with an Application to the Analysis of 4D Microscopy Data

We extend the concept of optical flow to a dynamic non-Euclidean setting. Optical flow is traditionally computed from a sequence of flat images. It is the purpose of this paper to introduce variational motion estimation for images that are defined on an evolving surface. Volumetric microscopy images depicting a live zebrafish embryo serve as both biological motivation and test data.Comment: The final publication is available at link.springer.co

Conhecimentos, modelos, e raciocínio condicional

A interpretação de frases, e em particular a interpretação de frases condicionais, pode ser modulada quer pelo significado das mesmas, pelos referentes, ou pelos conhecimentos gerais. O presente estudo examina o efeito pragmático dos conhecimentos no raciocínio a partir de pares de premissas condicionais. De acordo com a teoria dos modelos, inferências com a mesma forma, mas com conteúdos diferentes, deverão gerar um padrão de inferências diferente. Consideremos as seguintes premissas: Se a Maria não está em Paris, então ela está em França. Se a Maria está em França, então ele é estudante. A primeira premissa explora a inclusão espacial (Paris é em França), pelo que numa possibilidade Maria não está em Paris mas está em França, e noutra possibilidade Maria está em Paris e portanto está também em França. Assim, é impossível a Maria não estar em França, pelo que os indivíduos tenderão a inferir a partir da segunda premissa que ela é estudante. Em contraste, se considerarmos as seguintes premissas, que tem a mesma forma que as do exemplo anterior, mas um conteúdo diferente: Se o João não está em Roma, então ele está em França.Se o João está em França, então ele é estudante. A primeira premissa explora a exclusão espacial (Roma não é em França), pelo que numa possibilidade João não está em Roma e está em França, e noutra possibilidade ele está em Roma e não está em França. Assim, os indivíduos não têm nenhuma base para a inferência categórica de que ele é estudante, e deverão tender para a conclusão condicional de que Se o João não está em Roma então ele é estudante. Os problemasde inclusão geram menos possibilidades do que os problemas de exclusão, pelo que a teoria dos modelos prediz que os problemas de inclusão deverão ser mais fáceis do que os problemas de exclusão.O artigo relata duas experiências que corroboram as previsões da teoria dos modelos. Na Experiência 1, os participantes dão mais conclusões categóricas nas premissas de inclusão, mas apenas algumas conclusões condicionais nas premissas de exclusão. De facto, comas premissas de exclusão, obtém-se muitas conclusões outras. Para evitar isso fizemos uma segunda experiência, onde os participantes escolhem a conclusão a partir de quatro que são fornecidas: conclusão categórica; conclusão condicional; ambas; nenhuma (ao contrárioda Experiência 1, onde os participantes escreviam a conclusão). A Experiência 2 replica a superioridade de conclusões categóricas com as premissas de inclusão, e encontra a superioridade de conclusões condicionais com as premissas de exclusão

Comparative study of phytochemicals and antioxidant potential of wild edible mushroom caps and stipes

A comparative study of the organic acids and phenolics composition and of the total alkaloids content of entire wild edible mushrooms (Russula cyanoxantha, Amanita rubescens, Suillus granulatus and Boletus edulis) and correspondent caps and stipes was performed. All species presented oxalic, citric, malic and fumaric acids, with A. rubescens exhibiting the highest total organic acids content. Organic acids were preferably fixed in the cap. Among phenolics, only p-hydroxybenzoic acid was found in A. rubescens and S. granulatus, in very low amounts. B. edulis was the species that presented the highest total alkaloid amounts. Except for this species, alkaloids mainly accumulated in the cap. All of the species exhibited a concentration-dependent scavenging ability against DPPH . B. edulis revealed the highest antioxidant capacity. The cap seemed to be the part with highest antioxidant potential. Some relationships between chemical composition and antioxidant capacity were consideredFundação para a Ciência e a Tecnologia for a grant (SFRH/BD/22108/2005

Rotary orbital suspension culture of embryonic stem cell-derived neural stem/progenitor cells: impact of hydrodynamic culture on aggregate yield, morphology and cell phenotype

Embryonic stem (ES)-derived neural stem/progenitor cells (ES-NSPCs) constitute a promising cell source for application in cell therapies for the treatment of central nervous system disorders. In this study, a rotary orbital hydrodynamic culture system was applied to single-cell suspensions of ES-NSPCs, to obtain homogeneously-sized ES-NSPC cellular aggregates (neurospheres). Hydrodynamic culture allowed the formation of ES-NSPC neurospheres with a narrower size distribution than statically cultured neurospheres, increasing orbital speeds leading to smaller-sized neurospheres and higher neurosphere yield. Neurospheres formed under hydrodynamic conditions (72 h at 55 rpm) showed higher cell compaction and comparable percentages of viable, dead, apoptotic and proliferative cells. Further characterization of cellular aggregates provided new insights into the effect of hydrodynamic shear on ES-NSPC behaviour. Rotary neurospheres exhibited reduced protein levels of N-cadherin and ß-catenin, and higher deposition of laminin (without impacting fibronectin deposition), matrix metalloproteinase-2 (MMP-2) activity and percentage of neuronal cells. In line with the increased MMP-2 activity levels found, hydrodynamically-cultured neurospheres showed higher outward migration on laminin. Moreover, when cultured in a 3D fibrin hydrogel, rotary neurospheres generated an increased percentage of neuronal cells. In conclusion, the application of a constant orbital speed to single-cell suspensions of ES-NSPCs, besides allowing the formation of homogeneously-sized neurospheres, promoted ES-NSPC differentiation and outward migration, possibly by influencing the expression of cell–cell adhesion molecules and the secretion of proteases/extracellular matrix proteins. These findings are important when establishing the culture conditions needed to obtain uniformly-sized ES-NSPC aggregates, either for use in regenerative therapies or in in vitro platforms for biomaterial development or pharmacological screening.The authors would like to acknowledge Professor Domingos Henrique (Instituto de Medicina Molecular, Lisbon) for providing the ES 46C cell line. This study was supported by FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE (Grant No. FCOMP‐01‐0124‐FEDER‐021125) and by National Funds through FCT – Fundação para a Ciência e a Tecnologia (Grant No. PTDC/SAU‐BMA/118869/2010). I. F. Amaral is supported by QREN through programme ON.2 (Grant No. NORTE‐07‐0124‐FEDER‐000005) and M. J. Oliveira is an Investigator FCT Fellow

Nuclei Detection Using Mixture Density Networks

Nuclei detection is an important task in the histology domain as it is a main step toward further analysis such as cell counting, cell segmentation, study of cell connections, etc. This is a challenging task due to the complex texture of histology image, variation in shape, and touching cells. To tackle these hurdles, many approaches have been proposed in the literature where deep learning methods stand on top in terms of performance. Hence, in this paper, we propose a novel framework for nuclei detection based on Mixture Density Networks (MDNs). These networks are suitable to map a single input to several possible outputs and we utilize this property to detect multiple seeds in a single image patch. A new modified form of a cost function is proposed for training and handling patches with missing nuclei. The probability maps of the nuclei in the individual patches are next combined to generate the final image-wide result. The experimental results show the state-of-the-art performance on complex colorectal adenocarcinoma dataset.Comment: 8 pages, 3 figure

Semantic scene classification for image annotation and retrieval

We describe an annotation and retrieval framework that uses a semantic image representation by contextual modeling of images using occurrence probabilities of concepts and objects. First, images are segmented into regions using clustering of color features and line structures. Next, each image is modeled using the histogram of the types of its regions, and Bayesian classifiers are used to obtain the occurrence probabilities of concepts and objects using these histograms. Given the observation that a single class with the highest probability is not sufficient to model image content in an unconstrained data set with a large number of semantically overlapping classes, we use the concept/object probabilities as a new representation, and perform retrieval in the semantic space for further improvement of the categorization accuracy. Experiments on the TRECVID and Corel data sets show good performance. © 2008 Springer Berlin Heidelberg

Vascular Training Does Matter in the Outcomes of Saphenous High Ligation and Stripping

Objective: Varicose vein (VV) surgery is frequently performed by surgeons without formal vascular training. We aimed to compare the outcomes of the procedure based on the background of the surgeon. Methods: All patients registered with VV surgery between 2004 and 2016 in Portuguese public hospitals were included in the study. Intrahospital outcomes were assessed from this administrative database. A random multicenter sample of 315 patients submitted to saphenous high ligation and stripping (175 patients from six vascular surgery departments and 140 patients from five general surgery divisions) were further queried over the phone, whereby additional nonregistered outcomes were evaluated: preoperative venous ultrasound, impact on quality of life by the 14-item Chronic Venous Insufficiency Quality of Life Questionnaire, visual analogue scale evaluation (score of 1 to 5) of the aesthetic results and general satisfaction, work absence days, and time to return to physical activities. Results: In 13 years, there were 153,382 patients submitted to VV surgery. Of these, 49% were operated on by general surgeons and 40% by vascular surgeons; in 11%, it was not possible to identify the specialty performing the operation. Twenty-three deaths were registered (no differences between groups). In the general surgery group, 14% of patients were hospitalized for more than one night compared with 3% in the vascular group (P < .001). Reintervention rate during the period analyzed was significantly higher in the general surgery group (13.5% vs 8.2%; P < .001). Rate of outpatient surgery was higher in the vascular surgery group (60% vs 36%; P < .001). Phone query revealed similar overall satisfaction and improvement in quality of life in both groups (4.2 vs 4.0 [P = .275] and 35% vs 36% [P = .745], respectively). However, patients operated on by general surgeons reported worse surgical scars (2.8 vs 2.1; P = .007), higher number of residual VVs (2.4 vs 1.7; P = .006), and higher number of days absent from work (40 vs 27 days; P = .005) and took longer to resume physical activities (60 vs 41 days; P = .001). Conclusions: Despite that the majority of VV surgery in Portugal is executed by general surgeons, this study highlights important advantages when it is performed by surgeons with vascular training.info:eu-repo/semantics/publishedVersio