Quorum sensing in Candida species

Quorum sensing is the ability of micro-organisms to communicate, via signalling molecules, in order to coordinate their behaviour. Farnesol and tyrosol were the first molecules identified as Candida albicans quorum sensing molecules. Nowadays non-Candida albicans Candida species, as Candida dubliniensis, Candida parapsilosis, Candida krusei, Candida glabrata and Candida tropicalis, are emerging as pathogens and the identification of their extracellular molecules as well of their effect is of utmost importance. Farnesol, which was firstly described as having an effect on C. albicans morphology and also on C. dubliniensis, was shown to affect C. krusei, C. glabrata and C. tropicalis growth in suspension, without affecting their morphology. Additionally other alcohols as 1-dodecanol, E-nerolidol, 2-phenylethanol and isoamylalchool, have been identified in C. albicans and C. dubliniensis suspended and sessile supernatants. Interestingly, phenylethanol production increases along time, both for planktonic and biofilm cells and for both species. These alcohols were also found to cause high inhibition of filamentation on those two species. Moreover, those molecules were also shown to be secreted by other Candida species and at physiological levels affected C. parapsilosis and C. tropicalis biofilms

Decision trees for loss prediction in retail - case of Pingo Doce

Project Work presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Knowledge Management and Business IntelligenceThe use of data mining as a way of solving problems from the widest range of areas with the main purpose of gaining competitive advantage is rising, specially in retail, an extremely competitive sector that requires an even bigger advantage. Additionally, food loss, beyond representing a huge waste of resources, can also be considered a major issue to the retail sector due to the financial losses originated from it. Thus, I proposed to help Pingo Doce, a well-known Portuguese retail company, to solve their food loss issue which, despite being the major cause of a huge drop in the company’s profits, has never been solved till this day. Therefore, this project focuses on the development of a classification algorithm that will allow to predict future significant losses in several fruits sold in certain Pingo Doce stores. To do so I applied a Decision Tree algorithm that, due to its representation in the form of if-then rules, will help to identify the main features that lead to a higher number of losses, namely the period of the year and the category to which each fruit belongs, among others. The dataset provided by the company contains variables that measure the quantity and value of sales, stocks, identified and unidentified losses, over a one-year period, and regarding 81 different fruits and 20 stores from all over the country. Additionally, I created new variables such as the criminality rate of the municipality and the climate class of each store, as well as the seasons and the day of the week in which each observation occurred. All these variables allowed me to create four different datasets that originated four different Classification Trees. The results show that, using a dataset with no information regarding stocks and sales, containing only variables that describe the characteristics of the stores, products and periods of time, as well as the value of product sold per unit of measurement, i.e. the price per unit of measurement of each fruit, it is possible to create a Decision Tree that reaches an accuracy of 74% and correctly predicts 82% of the observations that represent significant losses. The algorithm obtained allowed to identify the variables that are more prone to originate significant losses, namely: the day of the week, the fruit’s category, the season of the year, the position of that week in the respective month and the price at which the product is being sold

Pathogenesis and virulence of Candida albicans and Candida glabrata

Fungal infections in humans have historically received comparatively less attention than those caused by bacteria and viruses. This may, in part, stem from the relative differences in infection prevalence. However, the more widespread use of immunosuppressive therapy, invasive surgery and medical devices in modern medicine has resulted in a more frequent occurrence of human fungal infection. There are a number of fungi that can cause human disease. However, it is arguably a species of the genus Candida that are most often encountered. There are over 150 Candida species that are widely encountered in the environment and in animal hosts, however, only a small number are opportunistic pathogens of humans. Candida albicans is a polymorphic yeast-like fungus and undoubtedly the species most often recovered from human infection. As such, the virulence of C. albicans and its susceptibility to antifungal agents are often investigated. More recently, the prevalence of infections caused by non-C. albicansCandida species have increased and, amongst these, infections caused by Candida glabrata have received attention given its often-higher tolerance to frequently used antifungals exhibited by this species. The papers presented in this Special Issue have focused on aspects relating to host responses to Candida infection, the efficacy of novel therapeutic agents and also treatment regimes. The papers highlight novel findings in their respective areas, whilst also highlighting the need for further research in these key and largely under-researched areas of candidoses.(undefined)info:eu-repo/semantics/publishedVersio

The role of individual differences in shame-induced behavior: a review of the literature and investigation of the contribution of attachment individual differences in predicting prosocial behavior following shame

In this article I will review research on the role of individual differences in predicting shameinduced behavior. Shame emerges essentially from a perception that one is viewed as unattractive by others and serves the important evolutionary function of warning individuals that they may be rejected and excluded by others. To help people deal with the threat of rejection, shame is postulated to motivate them to engage in socially valued behaviors that will protect or improve their social images and in this way grant them the acceptance of others and prevent their loss of group membership. Nevertheless, research has for decades focused on the negative interpersonal and psychological consequences of shame, with studies showing how this emotion leads people to hide when commiting transgressions, become more aggressive and hostile and exhibit dimished empathy for others. Only recently have the positive behavioral functions of shame begun to be uncovered, with studies showing how this emotion may also motivate people to behave in ways that promote interpersonal acceptance (e.g. striving in performance situations, engaging in reparations following wrongdoing and behaving prosocially towards others). However, the extent to which shame will promote one type of behavior or another is dependent upon individual differences that predispose people towards adaptiveness or maladaptiveness in the face of this emotion. Because space does not allow for a consideration of all such relevant individual differences, I will review evidence of the role of self-esteem and attachment individual differences in predicting adaptive versus maladaptive behavior following shame.Neste artigo serão revistos os resultados da investigação existente acerca do papel das diferenças individuais na predição do comportamento em situações de vergonha. A vergonha surge essencialmente de percepções de ausência de atractividade social aos olhos dos outros e serve a importante função evolucionária de avisar os indivíduos de que podem ser rejeitados ou excluídos. Por forma a lidar com a ameaça da rejeição, tem sido defendido que a vergonha motiva os indivíduos a terem comportamentos socialmente desejáveis que irão proteger ou melhorar as suas imagens sociais aos olhos dos outros e assim garantir-lhes que são aceites por eles. No entanto, a investigação durante décadas focou-se nas consequências interpessoais negativas da vergonha, com vários estudos a demonstrar como esta emoção leva as pessoas a fugir quando cometem transgressões, tornar-se mais agressivas e hostis e exibir menor empatia pelos outros. Apenas recentemente têm as consequências interpessoais da vergonha vindo a ser desvendadas, com alguns estudos a evidenciarem que esta emoção também pode motivar as pessoas a comportar-se de formas que promovem a sua aceitação social (e.g. dedicação em domínios de performance, reparações após transgressões, comportamento prosocial). Porém, a medida em que a vergonha irá promover um tipo de comportamento ou o outro depende de diferenças individuais que predispõem as pessoas a comportar-se adaptativamente ou não quando confrontadas com esta emoção. Porque o espaço não permite a consideração em detalhe de todas as diferenças individuais relevantes para este tópico, evidência acerca do papel da auto-estima e da vinculação na predição do comportamento em situações de vergonha será revista em maior detalhe

Liposomal and Deoxycholate Amphotericin B Formulations: Effectiveness against Biofilm Infections of Candida spp.

Background: candidiasis is the primary fungal infection encountered in patients undergoing prolonged hospitalization, and the fourth leading cause of nosocomial bloodstream infections. One of the most important Candida spp. virulence factors is the ability to form biofilms, which are extremely refractory to antimicrobial therapy and very difficult to treat with the traditional antifungal therapies. It is known that the prophylaxis or treatment of a systemic candidiasis are recurrently taken without considering the possibility of a Candida spp. biofilm-related infections. Therefore, it is important to assess the effectiveness of the available drugs and which formulations have the best performance in these specific infections. Methods: 24-h-biofilms of four Candida spp. and their response to two amphotericin B (AmB) pharmaceutical formulations (liposomal and deoxycholate) were evaluated. Results: generally, Candida glabrata was the less susceptible yeast species to both AmBs. MBECs revealed that it is therapeutically more appealing to use AmB-L than AmB-Deox for all Candida spp. biofilms, since none of the determined concentrations of AmB-L reached 10% of the maximum daily dose, but both formulations showed a very good capacity in the biomass reduction. Conclusions: the liposomal formulation presents better performance in the eradication of the biofilm cells for all the species in comparison with the deoxycholate formulation.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte and Célia F. Rodrigues’ [SFRH/BD/93078/2013] Ph.D. grant. The authors thank the Project “BioHealth—Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2—O Novo Norte), QREN, FEDER.info:eu-repo/semantics/publishedVersio

Portrait of matrix gene expression in Candida glabrata biofilms with stress induced by different drugs

(1) Background: Candida glabrata is one of the most significant Candida species associated with severe cases of candidiasis. Biofilm formation is an important feature, closely associated with antifungal resistance, involving alterations of gene expression or mutations, which can result in the failure of antifungal treatments. Hence, the main goal of this work was to evaluate the role of a set of genes, associated with matrix production, in the resistance of C. glabrata biofilms to antifungal drugs. (2) Methods: the determination of the expression of BGL2, XOG1, FKS1, FKS2, GAS2, KNH1, UGP1, and MNN2 genes in 48-h biofilms cells of three C. glabrata strains was performed through quantitative real-time PCR (RT-qPCR), after contact with Fluconazole (Flu), Amphotericin B (AmB), Caspofungin (Csf), or Micafungin (Mcf). (3) Results: Mcf induced a general overexpression of the selected genes. It was verified that the genes related to the production of -1,3-glucans (BGL2, XOG1, GAS2) had the highest expressions. (4) Conclusion: though -1,6-glucans and mannans are an essential part of the cell and biofilm matrix, C. glabrata biofilm cells seem to contribute more to the replacement of -1,3-glucans. Thus, these biopolymers seem to have a greater impact on the biofilm matrix composition and, consequently, a role in the biofilm resistance to antifungal drugs.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte and Célia F. Rodrigues’ [SFRH/BD/93078/2013] Ph.D. grant. We also would like to acknowledge MSD® and Astellas® for the kind donation of Caspofungin and Micafungin, respectivelyinfo:eu-repo/semantics/publishedVersio

Analysis of web information-seeking behavior of users with different levels of health literacy

Literacia em Saúde é definida como "o nível pelo qual os indivíduos podem obter, processar, compreender e comunicar informação relacionada com saúde necessária para tomar decisões de saúde informadas". Os utilizadores com um baixo nível de literacia em saúde têm menos conhecimentos das suas condições médicas, maior dificuldade em seguir as instruções e compreender a informação dada pelos médicos. Cada vez mais, as pessoas recorrem à web para pesquisar sobre informação de saúde. As dificuldades que os utilizadores de baixa literacia têm no mundo real provavelmente persistem no mundo virtual. O principal objetivo deste estudo é analisar os comportamentos de pesquisa de utilizadores com diferentes níveis de literacia em saúde. Pretende-se identificar diferenças entre pessoas com baixa e alta literacia de saúde que depois possam ser utilizadas para a melhoria dos sistemas de recuperação e contribuir, entre outros, para facilitar o acesso à informação e educação das pessoas com baixa literacia. Este estudo surge na sequência de um trabalho prévio que incluiu a anotação dos registos de vídeo de uma experiência com utilizadores realizada anteriormente. Com base na versão preliminar de análise do trabalho anterior, foi proposto um esquema de classificação de eventos que engloba tipos de interação relativos ao navegador, motor de pesquisa e páginas web. Cada tipo de interação é composto por eventos que, por sua vez estão associados a variáveis de análise. Dentro deste esquema, foram construídos módulos para analisar as interrogações de pesquisa submetidas. Com base neste esquema, foi revista a anotação dos vídeos e foi realizada a análise de dados de forma descritiva e inferencial. Os principais resultados demonstram que o grupo de baixa literacia em saúde utilizou sobretudo a caixa do motor de pesquisa e a funcionalidade de voltar atrás; interagiu mais tempo com página de resultados do motor de pesquisa, clicando mais com o botão esquerdo do rato e fazendo scrolling. Por outro lado, o grupo de alta literacia em saúde utilizou mais a barra de endereço e a funcionalidade de selecionar o texto do URL. Na página de resultados do motor de pesquisa este grupo fez mais cliques com o botão direito. A nível de reformulação de interrogações, que ocorrem no contexto da mesma necessidade de informação, os utilizadores com baixa literacia em saúde usaram mais as reformulações "totalmente novas", ou seja, sem termos em comum com a interrogação anterior. Por sua vez, o grupo de alta literacia em saúde fez mais reformulações.Health Literacy is "the level by which individuals can obtain, process, understand and communicate health-related information necessary to make informed health decisions". Users with a low level of health literacy are less aware of their medical conditions, more difficult to follow instructions and understand doctors' information. Increasingly, people turn to the web to search for health information. Low literacy users' difficulties in the real world are likely to continue to exist in the virtual world. The main objective of this study is to analyze the search behavior of users with different levels of health literacy. It intends to identify differences between people with low and high health literacy that can then be used to improve retrieval systems and contribute, among others, to facilitate access to information and education by people with low literacy. This study follows a previous work that included annotating video records of experience with users previously carried out. Based on the preliminary analysis version of the previous work, an event classification scheme was proposed that includes types of interactions related to the browser, search engine, and web pages. Each type of interaction is composed of events that, in turn, are associated with analysis variables. Within this scheme, modules were built to analyze the formulation of search queries. Based on this scheme, the annotation of the videos was revised, and the data analysis was performed in a descriptive and inferential manner. The main results demonstrate that the low health literacy group used mainly the search engine box and the backward feature. On the search engine results page, they clicked more with the left mouse button. On the results page, they spent more time on the interaction, mainly scrolling. On the other hand, the high health literacy group made more use of the address bar and the functionality of selecting the URL text. On the search engine results page, this group made more right-clicks. At the level of reformulations, which occur in the context of the same need for information, users with low health literacy used more "totally new" reformulations, that is, without terms in common with the previous question. In turn, the high health literacy group did more reformulations

Candida albicans virulence factors and its pathogenicity

Candida albicans lives as commensal on the skin and mucosal surfaces of the genital, intestinal, vaginal, urinary, and oral tracts of 80% of healthy individuals [...]We would like to thank all the authors for their interesting contributions to this Special Issue. We are grateful to all the reviewers for their insightful and helpful recommendations. We would also like to thank the Microorganisms editorial office staff for all their assistance and the opportunity to organize this Special Issue.info:eu-repo/semantics/publishedVersio

Candida albicans and Candida dubliniensis: comparison of biofilm formation in terms of biomass and activity

Candida albicans and C. dubliniensis are two species responsible for oral candidiasis, especially in immunocompromised patients. Microbial infection is preceded by adherence and biofilm formation. Biofilm formation represents the most common form of C. albicans in the oral cavity and is considered to be one of the most important virulence factors. In this study, the biofilm formation ability of C. dubliniensis was compared with that of C. albicans in terms of biomass (quantified using crystal violet) and activity (assessed by formazan salts formation). Both species formed heterogeneous biofilms; however, species and strain variations were seen in the quantification of biomass and activity. There was no correlation between pseudohyphae formation and biofilm formation capability.Fundação para a Ciência e a Tecnologia (FCT) - grant BD3195/2000, project POCTI/BIO/42638/2001