598 research outputs found
Social media and tourism : a wishful relationship
For decades hospitality firms were used to domain the communication process. Thematic social network sites such as TripAdvisor became very important tools for travelers when deciding which hotels to book, and what restaurants and tourist attractions to visit, been a visible part of tourism communication evolution. Evidence suggests that e-WOM serves as a primary information source when tourists choose destinations, hotels, and other experiences. The role and use of social media in tourists’ decision making has been widely discuss in tourism and hospitality research, especially in the research phase of the tourist’ travel planning process. With the wide adoption of social media the influence of customers’ word-of-mouth increased and influences not only the research phase, but the repetition and overall customers’ experiences. To answer these questions a model assessing e-wom was developed and data was gathering from TripAdvisor regarding customer’s opinion in restaurant experiences. The results found establish the bases for understanding tourists’ engagement level and profiles.N/
The Good, the Bad and the Ugly: Food Quality in UGC
AbstractUser-generated content diffusion on social networks has triggered an explosive attention in various disciplines. Within tourism activities, social media has growth in the past years rapidly through regular social network sites, or thematic social network sites such as TripAdvisor. The present study aims to provide a deeper insight into this matter, having as starting point the thought that clients posts good or bad reviews, regarding to different aspects of their experience; and, that a client who has a good experience in restaurant tends to revisit it and recommended it to friends, as opposite if the experience was bad they tell this to friend and recommend not visit. To assess customers’ reviews of restaurants, data was gathered on TripAdvisor of Top 10 restaurants in two island context Azores and Hawaii. All the comments were studied carefully and categorized in set of dimensions that measured how the entirety of a meal was perceived: sight, hearing, smell, taste and touch. As the results showed, food is the most decisive variable adopted in the UGC. Additionally, our findings support the notion that the overall quality of the meal reflects a lot more than flavor or taste of the food. To these elements, we need to add visual effect, freshness of the ingredients, and healthiness of the meal, among others as main contents spread on SNS. Thus, results reinforce the literature relative to the social media and ads to the knowledge of the contents created and shared by tourists relative to restaurant experience as a whole
Neuropsychiatric involvement in systemic sclerosis : prevalence and associated risk factors
Orientador: Simone AppenzellerTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Introdução: A Esclerose Sistêmica (ES) é uma doença autoimune crônica caracterizada por vasculopatia, ativação imune e fibrose. O envolvimento neurológico foi, outrora, considerado raro e associado a complicações da doença. Nas últimas décadas, no entanto, prevalências maiores de alterações neuropsiquiátricas foram descritas e associações à fisiopatologia da doença foram aventadas. Estudos recentes demonstram hipofluxo cerebral e lesões hiperintensas em substância branca encefálica, sugerindo comprometimento da microcirculação. Em conformidade, eventos isquêmicos associados ao comprometimento da macrovasculatura também foram mais prevalentes na doença. No entanto, poucos são os estudos que avaliam alterações metabólicas e fatores de risco cardiovasculares na ES, com apenas um estudo quantificando a prevalência de síndrome metabólica (SM). Deste modo, ainda carece a identificação de fatores de risco para o envolvimento neurológico na ES, bem como a determinação e caracterização da SM na doença. Objetivo: Descrever a frequência e as características do envolvimento neuropsiquiátrico e da SM na ES, determinar variáveis clínicas e imunológicas associadas a suas ocorrências e avaliar a associação entre a SM e o comprometimento neurológico na doença. Pacientes e métodos: Foram selecionados pacientes consecutivos do ambulatório de Reumatologia do HC-UNICAMP. O envolvimento neurológico foi avaliado clinicamente e exames complementares foram realizados caso houvesse alteração clínica. Transtornos de humor e ansiedade foram avaliados pelos inventários de depressão e ansiedade de Beck. Alterações cognitivas foram pesquisadas pela Avaliação Cognitiva de Montreal (MoCA). Atividade e gravidade da ES foram estabelecidas por meio do índice de atividade de Valentini e da escala de gravidade de Medsger. SM foi definida pelo critério diagnóstico do JIS. Resultados: Foram incluídos 151 pacientes [134 (88,74%) mulheres] com média de idade de 50,51 (±12,43) anos e 118 controles pareados para idade e sexo. O tempo médio de doença foi de 10,65 (±7,11) anos. Noventa e quatro (62,25%) pacientes tinham ES limitada, 42 (27,81%) ES difusa, 12 (7,95%) ES sine scleroderma e 3 (1,99%) doença precoce. SM estava presente em 65 (43,05%) dos pacientes e 23 (19,49%) dos controles (p<0,001) e foi associada a uma maior gravidade vascular da doença (p=0,005). Cento e dez pacientes (72,85%) completaram a avaliação neurológica. Alterações neuropsiquiátricas estavam presentes em 92 (83,64%) pacientes. Alteração cognitiva 68/83 (81,93%) e transtornos de humor e ansiedade [81 (73,64%)] foram os envolvimentos mais prevalentes. Comprometimento do sistema nervoso periférico foi identificado em 59 (53,64%) pacientes. Presença do anticorpo anti-topoisomerase I (p=0,03), atividade de doença (p=0,04), maior gravidade vascular (p=0,014) e geral (p=0,02) da doença foram associados a manifestações neuropsiquiátricas específicas. Exceto pela associação entre diabetes mellitus tipo 2 (DM2) e alterações cognitivas (p=0,043), não houve outras associações de fatores de risco para doença cardiovasculares ou de síndrome metabólica com envolvimento neuropsiquiátrico. Correlação negativa entre níveis de hemoglobina glicada (r= -0,428; p=0,002) e escores obtidos no MoCA foi observada. Conclusão: O envolvimento neuropsiquiátrico e a SM foram comuns em nossa amostra de pacientes. Atividade e gravidade de doença, bem como características imunológicas foram associadas a manifestações neurológicas específicas. Exceto pela presença de DM2, não houve evidência da associação de características metabólicas com o comprometimento neurológicoAbstract: Introduction: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by vasculopathy, immune cell activation, and fibrosis. Although once considered rare and associated to SSc manifestations (e.g interstitial lung disease, renal crisis, and cardiovascular involvement) or secondary to therapeutic interventions, in the last decade an increased prevalence of neuropsychiatric manifestations in SSc has been described. Recent studies have disclosed altered cerebral perfusion and white matter hyperintensity lesions, suggesting microvascular compromise. Accordingly, ischemic events due to macrovascular involvement were more prevalent in SSc and atherosclerotic process was allegedly considered to be accelerated. Few studies however have focused on prevalence of traditional cardiovascular risk factors in the disease and only one study have search for metabolic syndrome (MetS) prevalence SSc. Objective: To describe the prevalence and features of neuropsychiatric involvement and MetS in SSc as well as determine clinical, immunological and therapeutic features associated with their occurrence. Furthermore, to investigate the possible association between neuropsychiatric involvement and MetS in SSc. Patients and Methods: Consecutive SSc patients followed at the Rheumatology Division of the State University of Campinas were selected. Central (CNS) and peripheral nervous system (PNS) involvement were clinically evaluated at each patient visit and complementary evaluation whenever clinical investigation identified any alterations. Mood and anxiety disorders were assessed by Beck Depression Inventory and Beck Anxiety Inventory. Cognitive function was evaluated using Montreal Cognitive Assessment (MoCA). Disease activity and severity were stablished using Valentine Disease Activity Index and Medsger Disease Severity Scale, respectively. MetS was defined according to 2009 JIS diagnostic criteria. Nonparametric tests and correlation were used for statistical analysis. Results: 151 patients [134 (88.74%) female], mean age of 50.40 (±12.04) years and 118 age and sex matched controls followed in a primary care clinic were included in the study. SSc patients mean disease duration was 10.65 (±7.11) years. Ninety-four (62.25%) patients had limited cutaneous SSc, 42 (27.81%) diffuse cutaneous SSc, 12 (7.95%) sine scleroderma SSc and 3 (1.99%) "early disease". Sixty-five (43.05%) SSc patients and 23 (19.49%) had MetS (p<0.001) and MetS was associated with an increased vascular severity index (p=0.005). One hundred and ten (72.85%) patients fulfilled neurologic evaluation and 92 (83.64%) had some neuropsychiatric involvement. Cognitive impairment 68/83 (81.93%) and mood and anxiety disorders [81 (73.64%)] were the most prevalent neuropsychiatric alterations. Peripheral nervous system (PNS) compromise was identified in 59 (53.64%) patients. Anti-topoisomerase I antibody positivity (p=0.03), disease activity (p=0.04), increased vascular severity (p=0.014) and increased general severity (p=0.02) were associated to specific neuropsychiatric involvements. Apart from type 2 diabetes mellitus (T2DM) and cognitive impairment (p=0.043) there was no other association of traditional cardiovascular risk factors or metabolic syndrome and neuropsychiatric involvement. Inverse correlation between glycated hemoglobin (HbA1c) (r= -0,428; p=0,002) MoCA scores were observed. Conclusions: Neuropsychiatric involvement was common among the selected group of patients. Disease activity and severity as well as immunologic characteristics were associated to neurologic manifestations. Besides T2DM, no other association of metabolic features and neurologic involvement has been identifiedDoutoradoClinica MedicaDoutor em Ciência
A classification method based on a cloud of spheres
Publisher Copyright:
© 2023 The Author(s)In this article we propose a binary classification model to distinguish a specific class that corresponds to a characteristic that we intend to identify (fraud, spam, disease). The classification model is based on a cloud of spheres that circumscribes the points of the class to be identified. It is intended to build a model based on a cloud and not on a disjoint set of clouds, establishing this condition on the connectivity of a graph induced by the spheres. To solve the problem, designed by a Cloud of Connected Spheres, a quadratic model with continuous and binary variables (MINLP) is proposed with the minimization of the number of spheres. The issue of connectivity implies in many models the imposition of an exponential number of constraints. However, because of the specific conditions of the problem under study, connectivity is enforced with linear constraints that scale quadratically with K, which serves as an upper bound on the number of spheres. This classification model is effective when the structure of the class to be identified is highly non-linear and non-convex, also adapting to the case of linear separation. Unlike neural networks, the classification model is transparent, with the structure perfectly identified. No kernel functions are used and it is not necessary to use meta-parameters unless it is intended also to maximize the separation margin as it is done in SVM. Finding the global optima for large instances is quite challenging, and to address this, a heuristic is proposed. The heuristic demonstrates nice results on a set of frequently tested real problems when compared to state-of-the-art algorithms.publishersversionpublishe
Investigating the Global Properties of a Resource Theory of Contextuality
Resource theories constitute a powerful theoretical framework and a tool that
captures, in an abstract structure, pragmatic aspects of the most varied
theories and processes. For physical theories, while this framework deals
directly with questions about the concrete possibilities of carrying out tasks
and processes, resource theories also make it possible to recast these already
established theories on a new language, providing not only new perspectives on
the potential of physical phenomena as valuable resources for technological
development, for example, but they also provide insights into the very
foundations of these theories. In this work, we will investigate some
properties of a resource theory for quantum contextuality, an essential
characteristic of quantum phenomena that ensures the impossibility of
interpreting the results of quantum measurements as revealing properties that
are independent of the set of measurements being made. We will present the
resource theory to be studied and investigate certain global properties of this
theory using tools and methods that, although already developed and studied by
the community in other resource theories, had not yet been used to characterize
resource theories of contextuality. In particular, we will use the so called
cost and yield monotones, extending the results of reference Quantum 4, 280
(2020) to general contextuality scenarios.Comment: Preliminary version, comments welcom
The “ins and outs” of prostate metabolism towards carcinogenesis: the case of methoxychlor
The last years have witnessed the emergence of metabolic reprogramming as a hallmark of cancer. The changes in cancer cell metabolism include, among others, a shift in glucose metabolism from oxidative phosphorylation to aerobic glycolysis, which culminates in an increased lactate production and acidification of microenvironment favoring tumor progression. We and others previous work have shown that steroid hormones play a relevant role driven the metabolic changes associated with development and progression of prostate cancer. Nevertheless, the panoply of metabolic (de)regulators linked with prostate cancer remains poorly known. Endocrine-disrupting chemicals are a group of compounds that interfere with the synthesis, secretion, and metabolism of natural hormones, which have also been implicated in carcinogenesis. Methoxychlor (MXC) is a chlorinated pesticide widely dispersed in the environment by its use in agricultural activities, and several reports have demonstrated its estrogenic properties. However, the MXC effects inducing metabolic alterations in prostate cells are largely unknown. This study aimed to analyze the effect of MXC on cell viability, apoptosis and glycolytic metabolism of neoplastic (LNCaP and PC3) and non-neoplastic (PNT1A) human prostate cells. For this purpose, LNCaP, PC3, and PNT1A cells were cultured in the presence or absence of a range of MXC concentrations (0, 0.1, 1, 10 and 100 µM) for 48 and 72 hours. MTT assays performed for all experimental conditions demonstrated that MXC diminished the viability of both neoplastic and non-neoplastic prostate cells in a time- and concentration-dependent manner. The 100 µM concentration and a treatment period of 48 hours were the conditions selected for evaluation of the effect of MXC on apoptosis and glycolytic metabolism of all cell lines under study. Protein expression and activity of target modulators of these biological processes were assessed by means of Western blot analysis and biochemical assays. The obtained results showed that MXC-treatment decreased the apoptotic rate of PNT1A cells, despite the observed decrease in cell proliferation. Curiously, in LNCaP- and PC3-treated cells MXC had an opposite effect increasing caspase-3 activity, the effector protein of apoptosis, and up-regulating the expression of apoptotic regulators.
Regarding metabolism, measurement of glucose and lactate levels by spectrophotometric assays showed that MXC stimulated the glycolytic flux in both non-neoplastic and neoplastic human prostate cell lines, as indicated by the enhanced glucose consumption and lactate production. This metabolic response was underpinned by the increased expression of glucose transporters and activity of glycolytic enzymes.
The present findings demonstrated that MXC may have a role in the development and progression of prostate cancer by suppressing apoptosis in non-neoplastic prostate epithelial cells and stimulating the glycolytic pathway in both non-neoplastic and neoplastic cells. Moreover, the evidence gathered herein highlights for the impact of MXC in other human diseases, such as diabetes, obesity, and infertility, since they are all associated with alterations in apoptosis and metabolism also.A capacidade de reprogramação metabólica apresentada pelas células tumorais tem emergido, nos últimos anos, como um dos “Hallmarks” do cancro. As alterações metabólicas típicas das células cancerígenas caracterizam-se essencialmente pela utilização da via glicolítica anaeróbia em detrimento da fosforilação oxidativa, o que culmina no aumento da produção de lactato, e na, consequente, acidificação do microambiente tumoral, o que favorece a progressão do cancro. Estudos anteriores do nosso grupo de investigação e outros demonstraram que as hormonas esteróides desempenham um papel relevante no estabelecimento das alterações metabólicas associadas ao desenvolvimento e progressão do cancro da próstata. Contudo, a panóplia completa dos potenciais (des)reguladores metabólicos relacionados com o cancro da próstata é ainda desconhecida. Os disruptores endócrinos são um grupo de compostos que interfere na síntese, secreção e metabolismo das hormonas naturais, os quais têm igualmente sido implicados na carcinogénese. O metoxicloro (MXC) é um pesticida organoclorado largamente disseminado no ambiente através do seu uso na atividade agrícola, tendo vários estudos demonstrado as suas propriedades estrogénicas. No entanto, os efeitos do MXC na indução de alterações metabólicas em células da próstata são totalmente desconhecidos. A presente dissertação tem como objetivo analisar o efeito do MXC na viabilidade celular, apoptose e metabolismo glicolítico de células da próstata humana, neoplásicas (LNCaP e PC3) e não neoplásicas (PNT1A). Com este propósito, as células LNCaP, PC3 e PNT1A foram mantidas em cultura na presença ou ausência de MXC (0, 0.1, 1, 10 and 100 µM) durante 48 e 72 horas. Os ensaios de (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) (MTT) realizados para todas as condições experimentais demonstraram que o MXC diminui a viabilidade das células da próstata neoplásicas, assim como das não neoplásicas, e de uma forma dependente do tempo de exposição e da concentração. A concentração de 100 µM e o tempo de tratamento de 48 horas foram as condições selecionadas para avaliação dos efeitos do MXC na apoptose e no metabolismo glicolítico de todas as linhas celulares em estudo. A expressão proteica e a atividade de moduladores alvo destes processos foram analisadas por Western Blot e ensaios bioquímicos. Os resultados obtidos revelaram que o tratamento com MXC diminuiu a taxa de apoptose das células PNT1A, apesar da diminuição da proliferação celular observada. Curiosamente, nas células LNCaP e PC3 tratadas com MXC verificou-se o oposto, ou seja, o aumento da atividade da caspase-3, a proteína efetora da apoptose, bem como da expressão de reguladores apoptóticos.
No que diz respeito ao metabolismo, a medição dos níveis de glicose e de lactato por ensaios espectrofotométricos mostrou que o MXC estimulou o fluxo glicolítico quer nas linhas celulares de próstata neoplásicas quer nas não neoplásicas, como indicado pelos aumentos observados no consumo de glicose e na produção de lactato. Esta resposta metabólica foi suportada pelo aumento da expressão dos transportadores de glicose e pela atividade de enzimas glicolíticas.
Os resultados obtidos demonstram que o MXC pode ter um papel no desenvolvimento e na progressão do cancro da próstata, suprimindo a apoptose nas células epiteliais de próstata não neoplásicas e estimulando a via glicolítica quer nas células não neoplásicas quer nas neoplásicas. Para além disso, estas evidências alertam para o impacto que o MXC também pode ter noutras doenças igualmente associadas a alterações na apoptose e metabolismo, como, por exemplo, a diabetes, a obesidade e a infertilidade
Using weight aggregation in tabu search for multiobjective exams timetabling problem
EnExams timetabling is a difficult task in many educational institutions. We can distinct two major sets of constraints when defining exams timetabling problems, categorized in soft and hard constraints. Guaranteing that any student as a non overlapping exams schedule and that necessary requirements like rooms and teacher are available are consider hard constraints. An evenly distributed schedule, a short duration of the overall exams period can be regarded as soft constraints. To handle soft constraints under the hard constraints verification we adopted a multiobjective optimization approach. This problem is NP-hard for which we have developed an heuristic tabu search method to find a solution. Tabu search comprises an iterative local search defined as a neighborhood inspection of a certain point in the search space. To find an improved solution we have to evaluate points in this neighborhood which can be considered a multiple attribute decision problem. In this context we have used multicriteria methods in order to rank the solutions
Adulteration of Dietary Supplements by the Illegal Addition of Synthetic Drugs: a review
In the last few years, the consumption of dietary supplements, especially those having plants as ingredients, has been increasing due to the common idea that they are natural products posing no risks to human health. In the European Union and the United States, dietary supplements are legally considered as foods/special category of foods, thus are not being submitted to any safety assessment prior to their commercialization. Among the issues that can affect safety, adulteration by the illegal addition of pharmaceutical substances or their analogs is of major concern since unscrupulous producers can falsify these products to provide for quick effects and to increase sales. This review discusses the various classes of synthetic drugs most frequently described as being illegally added to dietary supplements marketed for weight loss, muscle building/sport performance and sexual performance enhancement. Information regarding regulation and consumption is also presented. Finally, several conventional and advanced analytical techniques used to detect and identify different adulterants in dietary supplements and therefore also in foods, with particular emphasis on plant food supplements, are critically described. This review demonstrates that dietary supplement adulteration is an emerging food safety problem and that an effective control by food regulatory authorities is needed to safeguard consumers.This work was supported by European Union (FEDER funds through COMPETE) and Natl. Funds (FCT, Fundação para a Ciência e Tecnologia) through projects EXPL/DTP-SAP/1438/2013 (Safety of plant food supplements: searching for adulterant pharmaceutical drugs and plants) and LAQV UID/QUI/50006/2013.info:eu-repo/semantics/publishedVersio
Food supplements adulteration with undeclared synthetic phosphodiesterase type-5 drugs (PDE-5) inhibitors
The use ofplant food supplements (PFS) in developed countries is becoming increasingly
popular mostly due to the consumers' widespread idea that natural products are safer
and healthier than conventional pharmaceutical drugs [l]. However, in the last years,
several studies have been showing the existence of gaps in PFS regulation that can
result in insuíficient quality control and intentional adulteration ofthese products [2].
Among the issues that can aíFect PFS safety, the illegal addition of pharmaceutical
substances is of major concern, since unscrupulous producers can dope PFS to provide
for quick effects.
Supplements used for sexual performance improvement are among the most popular
PFS used by males. One of the major concerns in this type of product is the possible
adulteration with drugs used for the treatment of erectile dysfunction, namely
synthetic phosphodiesterase type-5 (PDE-5) inhibitor drugs, such as sildenafil,
vardenafil and tadalafil which are approved prescription drugs being marketed as
Viagra (Pfizer, USA), Levitra (Bayer Pharmaceuticals Co., Germany) and Cialis (Elli
Lilly, USA), respectively. Since these drugs can present side eífects, its illegal addition
in PFS can seriously endanger consumers' health. In particular, individuais for whom
conventional PDE-5 inhibitor drugs are contraindicated and consequently use food
supplements as an alternative maybe at risk ifthe clandestine addition ofthese drugs
occurs. In the last years, the presence ofthis type ofdrugs have been detected by FDA
in the US, and reported in food supplements commercialized in Ásia, however studies
regarding this issue in the EU are almost inexistent.
For the presented reasons, an analytical methodology based on the use of high
performance liquid chromatography coupled to a fluorescence detector in series with a
photodiode array (HPLC-FL-PDA) is proposed for the detection ofPDE-5 inhibitors,
namely sildenafil and its analogue acetildenafil, vardenafil and tadalaíil, illegally added
to supplements used for aphrodisiac purposes.to FCT (PEst-C/EQB/LA0006/2013 and EXPL/DTP-SAP/1438/2013) and QREN
(NORTE-07-0124-FEDER-000069-CIÊNCIA DO ALIMENTO).info:eu-repo/semantics/publishedVersio
Determinants of Loyalty Intention in Portuguese Mobile Market
Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.Our work conceptualizes and highlights the determinants of customers’ loyalty in the Portuguese mobile market. We raise questions about the interrelationships of the cost and values dimensions and the consequences of these relationships on customer satisfaction and trust and consequently loyalty among different operators, addressing some recent models. By organizing and synthesizing the major research streams and tests empirically a conceptual framework through a SEM, with data gather in a survey of Portuguese clients, the present study advances knowledge on the nature of the relative importance of different components of loyalty to mobile communications operators. Some useful preliminary insights were produced related to customers’ retention process in primary mobile operator, which appears strongly related to price/quality, followed by the emotional connection to the operator staff and others clients. Nonetheless, a considerable number of issues were left for future research, including the possibility of extending the investigation to other countries
- …