480 research outputs found
A CASE STUDY ON THE EFFECT OF NEWS ON CRUDE OIL PRICE
Crude oil price volatility has an impact on the global economy and oil-dependent industries
and is influenced by supply and demand, geopolitical tensions, and the global
economy. Every day, a massive amount of textual information flows in the form of news
articles, which humans use to forecast future trends. News articles can have a significant
impact on the price of crude oil because they contain information about recent events,
trends, and advancements in the industry.
The purpose of this work is to investigate how news articles may affect crude oil prices,
using the concept of topic modeling and its potential for handling data. Using the webscraping
method, the data for the study comes from a large dataset of news articles about
the crude oil industry. These news articles were published between January 1 and December
31, 2022, and come from four different sources. The data was compiled using the
source Exchange Rates UK to demonstrate how the price of crude oil fluctuated during
this period. After the cleaning process was completed, the dataset contained a total of
1532 news articles.
The Latent Dirichlet Allocation (LDA) technique is suggested for extracting relevant
keywords from news articles and then using the findings as input features to forecast the
crude oil price.
The forecasting methods employed in the study were the Ridge model, the Random
Forest and XGBoost techniques, and the time series method ARIMAX. The outcomes of
the experiment indicate that the association between the meaning of the news articles and
the crude oil price is not sufficiently strong.
It is additionally concluded that the XGBoost algorithm reveal superior predictive
performance in the training set. As a result, XGBoost models for each month of 2022
were developed to investigate the impact of features and determine the most important
ones for the problem.A volatilidade dos preços do petróleo bruto tem um impacto na economia global e nas
indústrias dependentes do petróleo e é influenciada pela oferta e procura, por tensões geopolíticas
e pela economia global. Todos os dias uma enorme quantidade de informação
flui sob a forma de artigos de notícias e é utilizada pelo ser humano para prever tendências
futuras. Os artigos de notícias podem influenciar significativamente o preço do
petróleo bruto porque contêm informação sobre eventos recentes, tendências e avanços
na indústria.
O objetivo deste trabalho é investigar como os artigos de notícias podem afetar os
preços do petróleo bruto, utilizando o conceito de modelação de tópicos.
Utilizando o método web-scraping, os dados para o estudo provêm de um grande conjunto
de artigos de notícias sobre a indústria do petróleo bruto. Estes artigos foram publicados
entre 1 de janeiro e 31 de dezembro de 2022 e resultam de quatro fontes diferentes.
Os dados foram compilados usando a fonte Exchange Rates UK para demonstrar como
o preço do petróleo bruto flutuou ao longo deste período. Após a conclusão do processo
de limpeza, obteve-se um total de 1532 artigos de notícias.
A técnica Latent Dirichlet Allocation (LDA) é sugerida para extrair as palavras-chave
pertinentes dos artigos de notícias. Os seus resultados foram depois utilizados como variáveis
de entrada para prever o preço do petróleo bruto.
Os métodos de previsão utilizados no estudo foram os modelos Ridge, Random Forest,
XGBoost e ARIMAX. Os resultados indicam que a relação entre os artigos de notícias e o
preço do petróleo bruto não é suficientemente forte.
Conclui-se que o algoritmo XGBoost revela um desempenho preditivo superior no
conjunto de treino. Como resultado, foram desenvolvidos modelos XGBoost para cada
mês de 2022 para investigar o impacto das características e determinar as mais importantes
para o problema
First insights on the presence of the unfolded protein response in human spermatozoa
The unfolded protein response (UPR) is involved in protein quality control and is activated in response to several stressors. Although in testis the UPR mechanisms are well described, their presence in spermatozoa is contentious. We aimed to investigate the presence of UPR-related proteins in human sperm and the impact of oxidative stress induction in UPR activation. To identify UPR-related proteins in human sperm, a bioinformatic approach was adopted. To explore the activation of UPR, sperm were exposed to hydrogen peroxide (H2O2) and motility, vitality, and the levels of UPR-related proteins were assessed. We identified 97 UPR-related proteins in human sperm and showed, for the first time, the presence of HSF1, GADD34, and phosphorylated eIF2α. Additionally, the exposure of human sperm to H2O2 resulted in a significant decrease in sperm viability and motility and an increase in the levels of HSF1, HSP90, HSP60, HSP27, and eIF2α; all proteins involved in sensing and response to unfolded proteins. This study gave us a first insight into the presence of UPR mechanisms in the male gamete. However, the belief that sperm are devoid of transcription and translation highlight the need to clarify if these pathways are activated in sperm in the same way as in somatic cells.publishe
Contributos para a caracterização do género académico ‘Resposta de Desenvolvimento’
Uma vez que caracterizar os géneros do discurso académico permite identificar os processos de construção dos textos que os integram, permitirá também melhorar a proficiência dos estudantes do ensino superior. A este respeito, Parodi (2009), evidenciou não só a maior ou menor diversidade de géneros das leituras aconselhadas em diferentes cursos, como também a conveniência de basear as reflexões sobre os géneros em corpora extensos e adequadamente ricos.
Numa linha complementar, propomo-nos contribuir para a reflexão teórica sobre géneros do discurso académico, sob a perspetiva das práticas de escrita na universidade. Analisámos um corpus de 179 textos (de 500 a 1000 palavras), pertencentes ao género resposta de desenvolvimento, obtidos em exames de Ciências Humanas. Tendo selecionado respostas com sequências de tipo argumentativo, identificámos os parâmetros mais relevantes segundo os níveis textuais propostos por Adam (2001) – semântico, enunciativo-pragmático, composicional e estilístico-fraseológico: a) nível semântico – conteúdos adequados à área de estudo em causa, seleção de argumentos pertinentes, explicitação de tese; b) nível enunciativo-pragmático – marcas de contexto socioprofissional e das condições de produção; c) nível composicional – sequências argumentativas, estruturação em partes funcionalmente distintas; d) nível estilístico-fraseológico – léxico especializado, conetores discursivos, citações.
Estes parâmetros caracterizam os textos do género resposta de desenvolvimento, e permitem delimitá-lo relativamente a outras classes, o que contribuirá para o conhecimento do discurso académico, e, por outro lado, para a implementação de melhores práticas de produção escrita no ensino superior
A biodeterioração por insetos em contexto museológico. Conhecendo os agentes, para melhor gestão do risco.
Da introdução ao resumo/abstract: o surgimento de um género híbrido nas atas da Associação Portuguesa de Linguística
The aim of the paper is to retrace the emergence of the academic genre Abstract through the analysis of the “Associação Portuguesa de Linguística” Proceedings (2001–2010). Following the framework of the “Interactionnisme Sociodiscursif” (Bronckart, 1996), the main assumptions are: (i) genre properties are unfolded through texts; and (ii) within a given period, texts belonging to different genres may share linguistic, social and illocutionary properties until a self-sustained genre emerges (Adam, 2001; Maingueneau, 1998). The analysis took into account the abstract dimension of genres, and the empirical dimension of texts within a 3-level model that includes genre parameters, mechanisms of textual realization and genre markers (Coutinho & Miranda 2009). Data shows that the Abstract shares properties with the Introduction of the paper it summarizes. Its emergence as an independent genre thus points to intertextual origins.Projeto UID/LIN/04887/2013 do CELGA-ILTEC (cofinanciado pela Fundação para a Ciência e Tecnologia, QREN – Quadro de Referência Estratégico Nacional, COMPETE – Programa Operacional para a Competitividade e Desenvolvimento Nacional, NUTS II - Fundo da EU para o Desenvolvimento Regional e Horizons 2020)info:eu-repo/semantics/publishedVersio
Issues with publishing abstracts in English: challenges for Portuguese linguists’ authorial voices
This paper assesses the impact of publishing abstracts in English in the Portuguese
Linguistics Association (APL) Proceedings from 2001 to 2010. The study was carried out with a corpus
of 137 abstracts, follows a Text Linguistics model inspired by the Interactionnisme Sociodiscoursif and
links text features to the social practices and genre repertoires of this community. Quantitative data
show signs of a “Portuguese identity” in authors’ voices such as personal forms, move signaling, long
sentences, profuse embedding, heavy subjects, and variations in content selection, but also signs of
standard academic guideline-indexed choices in impersonal forms, template sentences, coordinated
constituents, nominalizations, and conventional text plans. Standard genre models and writing
features from “core” academic communities coexist with alternative and traditional ways of writing
and of disseminating knowledge, which is typical of a semiperipheral non-native English-speaking
community torn between conflicting language and cultural paradigms. These contrasting tendencies
are linked to identity changes within the community, as APL authors try to achieve international
recognition by publishing abstracts in English as a Foreign Language. Since the APL research
topic is the Portuguese language, the process mirrors the authors’ struggle between standard
internationalization in English and individual stance in Portuguese.info:eu-repo/semantics/publishedVersio
Issues of textual hybridity in a major academic genre: PhD dissertations vs. research articles
O trabalho apresenta as propriedades partilhadas pelos planos de texto de teses de doutoramento e de artigos científicos. A análise combina conceitos do Interacionismo Sociodiscursivo (Bronckart, 1996) e da Teoria do Texto – parâmetro de género, mecanismo de realização textual e marcador de género (Coutinho e Miranda 2009). No corpus de 130 teses da Universidade de Coimbra (2003-2012) foram identificados quatro tipos de planos de texto: estruturação por tópicos, IMRDC, (Introdução–Metodologia–Resultados–Discussão–Conclusão), antológico e misto (Swales, 2004; Santos e Silva, aceite). Os textos evidenciam dois tipos de hibridismo: mistura e encaixe de géneros (Mäntynen & Shore, 2014). As teses de ciências sociais e humanas partilham a estruturação por tópicos com os artigos dessas áreas disciplinares. Nas teses de ciências de base experimental predominam planos IMRDC (idênticos aos dos artigos dessas áreas) e antológicos (que incluem os artigos já publicados/submetidos), evidenciando-se no segundo caso uma dupla relação de hibridismo. Consequentemente, questiona-se a delimitação entre os dois géneros, e conclui-se que os objetivos, o contexto institucional, a extensão e a etiquetagem metatextual poderão ser os únicos critérios distintivos entre a tese e o artigo científico.The paper presents a study on properties shared by text plans of PhD dissertations and research articles. The analysis combines concepts from the Interactionnisme Sociodiscursif (Bronckart, 1996), and Text Theory - genre parameter, textual realization device and genre marker (Coutinho & Miranda, 2009). In the 130 University of Coimbra PhD dissertations (2003-2012) corpus, there are four types of text plans: topic-based, IMRDC (Introduction – Methods – Results – Discussion – Conclusion), anthology and mixed plans (Swales, 2004; Santos & Silva, accepted). Texts show two types of hybridity: genre blending and genre embedding (Mäntynen & Shore, 2014). In Social Sciences and Humanities, topic-based plans share the typical structure of these areas research articles. IMRDC are dominant in Sciences PhD dissertations, as in these areas research articles. There are also anthology plans, which sustain a double relationship with research articles by repeating already published, accepted or submitted texts. These hybridity issues challenge the separation between genres. Pragmatic aims, institutional context, text length and metatextual genre label may thus be the only parameters that separate both genres.Trabalho financiado no âmbito do projeto UID/LIN/04887/2013 do CELGA-ILTEC por FCT.info:eu-repo/semantics/publishedVersio
The Technology and Innovation Unit of the National Institute of Health: A sequencing and bioinformatics core facility specializing in public health genomics
The National Institute of Health (INSA) has a long tradition in investigating the molecular etiology of genetic and complex diseases. These activities greatly benefit from centralized sequencing services provided by the Technology and Innovation Unit (UTI). Its mission is to perform sequencing and genotyping assays in the framework of research, diagnosis and epidemiological surveillance, as well as to implement data analysis pipelines for the study of human gene variants. The equipment portfolio includes a NextSeq 550, a MiSeq, two 3500 AB Genetic Analyzers, a Fragment Analyzer and a 7500 Real-time PCR system. UTI provides results for average of 36.000 sequencing/fragment samples per year. The team has already performed >300 small genome, amplicon, gene panel (including clinical exome), 16S rRNA gene and RNA/microRNA next-generation sequencing assays for INSA and for several Universities in the scope of scientific collaborations. Technical procedures are conducted under a quality control system that includes external quality assessment for next-generation sequencing/Sanger sequencing and ISO 15189 accreditation for Sanger sequencing. UTI plays a key role in public health genomics, providing state-of-the-art equipment, centralized resources, technical expertise and short response times.This work was supported by Centre for Toxicogenomics and Human Health - UID/BIM/00009/2019 - and GenomePT project – POCI-01-0145-FEDER-022184info:eu-repo/semantics/publishedVersio
Full-scale ab initio 3D PIC simulations of an all-optical radiation reaction configuration at
Using full-scale 3D particle-in-cell simulations we show that the radiation
reaction dominated regime can be reached in an all optical configuration
through the collision of a 1 GeV laser wakefield accelerated (LWFA)
electron bunch with a counter propagating laser pulse. In this configuration
radiation reaction significantly reduces the energy of the particle bunch, thus
providing clear experimental signatures for the process with currently
available lasers. We also show that the transition between classical and
quantum radiation reaction could be investigated in the same configuration with
laser intensities of
Noise in neonatal intensive care units: a short review
Prematurity and low birth weight of newborns lead to the need of a special care in neonatal units, and their permanence in these places can be extended for a long period. Indoor environmental conditions, such noise levels above the recommended, may induce some risks, not only for the newborns development, but also for health care staff. This literature review aims to examine the studies related to noise in neonatal intensive care units to understand the sources and effects of noise, as well as some strategies to reduce noise exposure. The search strategy included an electronic search in databases (ISI Web of Knowledge and PubMed) of scientific articles published in English/Portuguese between 2000-2017. Studies providing data on noise levels found in the neonatal units, the effects on health of newborns and staff and the measures to minimize these effects were included. The exclusion criteria were as follows: duplicate printings; nonEnglish/Portuguese language; editorials, letters, patents, errata, meeting abstracts and conference papers. PRISMA methodology was followed to perform the review. Twenty-two articles were considered for full analysis. It is important to note that some potentially relevant studies were rejected due to language criteria. It was found that the noise levels to which the newborns and staff are exposed in NICU, often exceeds the recommended levels for these spaces. Evidence also shows several adverse health effects for newborns and health care staff perceptions of noise. There is no consensus regarding the best intervention to reduce noise levels.info:eu-repo/semantics/publishedVersio
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