Development of PNA-DNA Field-Effect Transistor-based biosensors

The high demand for devices with higher sensitivity as well cost-efficiency has put tremendous pressure on the biosensors field. The numerous advantages of Field effect transistors (FETs) such as small size, fast response, label free response, and possibility of on-chip integration of biosensor arrays with a future prospect of low-cost mass production, make their development highly desirable. An elec-trochemical deoxyribonucleic acid (DNA) biosensor using a synthesized ferrocene-based DNA interca-lator as a redox marker was investigated. A peptide nucleic acid (PNA) was employed as a capture probe and co-immobilized on electrodes with 6-mecarpto-hexanol (MCH) to control the surface density of the probe, and hybridized with complementary DNA. After hybridization, a ferrocene-based intercalator was introduced to bind with the PNA-DNA duplex and change the surface potential. Biologically sen-sitive field-effect transistor (BioFET) was used to monitor the DNA recognition. As confirmation, elec-trochemical impedance spectroscopy (EIS) was also used to characterize the different modification steps. Differential pulse voltammetry (DPV) was employed to evaluate the electrochemical signal of the intercalator, related to its interaction with the PNA-DNA duplex. An optimization of the PNA probe surface density was also tried, with the density being controlled by the MCH ratio in solution. Hybridi-zation of PNA-DNA with a PNA/MCH ratio of 1:29 was obtained in BioFET and EIS, the employed intercalator showed to have poor stability, both in application in BioFET as in DPV. Different ratios were tried and the use of different electrodes was also exploit

Equity research - Hyatt Hotels Corporation

Mestrado Bolonha em FinançasThe Equity Research Report that ensues contains a valuation on Hyatt Hotels Corporation (“HYATT”) and follows the format proposed by the CFA Institute. Only public information available on August 19th, 2021, was considered; therefore, any information made available after was not reflected. HYATT was chosen due to its focus on high-end segments, which would be interesting to analyse in the post-pandemic context. HYATT is a worldwide hospitality company that operates in all five continents with a portfolio that currently comprises more than 980 hotels. A leader in its industry, it displayed values of Total Revenues of $2.1Bn, Total Assets of$9.129Bn and a market capitalization of $7.061Bn in 2020YE. HYATT has a HOLD recommendation, presenting a 2022YE PT of$77.07/share, which translates into an 11.12% upside potential compared to its August 19th, 2021 closing price of $69.36/share, with high risk. This was computed through the WACC method, but other methods were performed to complement the analysis, namely the Adjusted Present Value (APV), the Flow to Equity, the Dividend-Discount Model (DDM) and the Relative Valuation through Peer’s multiples. The company’s shares are undervalued at present mainly due to the challenges posed by the COVID-19 pandemic on the world economy, which led to the rise of uncertainty and pessimistic expectations, causing downward pressure on both the demand and supply sides of the hotel industry. In addition, a sensitivity analysis was performed on WACC, long-term sustainable growth rate, RevPAR and number of rooms, which were considered risks to the PT.O projeto que se segue contém uma avaliação do Hyatt Hotels Corporation (“HYATT”) e respeita o formato proposto pelo CFA Institute. Apenas informação pública disponível a 19 de agosto de 2021 foi considerada, como tal informação apresentada após essa data não foi refletida. HYATT foi escolhido uma vez que se foca no segmento de luxo, algo que seria interessante analisar num contexto de pós-pandemia. HYAT é uma empresa hoteleira multinacional, que opera em todos os cinco continentes com um portfólio que reúne mais de 980 hotéis. Uma líder na sua indústria, apresentou valores de receitas na ordem dos$2.1 mil milhões, um total de ativos de $9.129 mil milhões e uma capitalização bolsista de$7.061 mil milhões. HYATT tem uma recomendação de investimento de MANTER, apresentando valores para o Preço Alvo de finais de 2022 de $77.07/ação, correspondendo a uma valorização potencial de 11.12$69.36/ação do dia 19 de agosto de 2021, com risco elevado. Tal foi calculado através do modelo WACC, mas outros modelos foram utilizados para complementar a análise, nomeadamente os modelos Adjusted Present Value (APV), o Dividend-Discount Model (DDM) e uma avaliação através dos múltiplos de empresas equiparáveis ao HYATT. As ações da empresa estão presentemente subvalorizadas maioritariamente devido aos desafios provocados pela pandemia do COVID-19 na economia mundial, o que levou ao aumento da incerteza e das expectativas pessimistas, provocando uma pressão negativa na procura e na oferta da indústria hoteleira. Adicionalmente, uma análise de sensibilidade foi realizada ao WACC, à taxa de crescimento de longo prazo, RevPAR e número de quartos, que foram considerados como riscos ao Preço Alvo.info:eu-repo/semantics/publishedVersio

Design de um brinquedo promotor de competências de atenção e concentração em crianças com PHDA

A presente tese de investigação em Design que se passa a apresentar, defende que o uso de artefactos lúdicos, analógicos e de construção, manuseados por meio de peças geométricas e de encaixe em contexto escolar desenvolvem competências de atenção e concentração nas crianças diagnosticadas com a Patologia de Perturbação de Hiperatividade e Défice de Atenção (PHDA) predominantemente desatentas, entre os 7 e os 11 anos, em idade infantil. O artefacto, de cariz inclusivo, foi pensado e desenvolvido de forma a garantir e agilizar a igualdade de oportunidades apoiando o sucesso educativo. Pretende ser utilizado pelo maior número de utilizadores, de forma a privilegiar, incentivar, motivar, possibilitar e habilitar todas as crianças, e provocar momentos prazerosos e sempre de aprendizagem e com foco foco no desenvolvimento da atenção e concentração da criança. O trabalho divide-se em duas partes distintas. A primeira parte caracteriza-se pela investigação de carácter bibliográfico e a segunda pela investigação empírica, o trabalho de campo. O estado da Arte, legitima e valida segundo o DMS-5 (2014), autores como Russell Barkley (2008), Mark Selikowitz (2010), João Lopes (2004), Luis de Miranda Correia & Vitor da Fonseca (2008), Keith Conners (2009), Nuno Lobo Antunes (2014), entre outros autores especialistas estudados das várias áreas científicas, que a falta de atenção e em mantê-la, é o núcleo problemático da patologia de PHDA e que esta compromete diariamente a vida escolar, familiar e social da criança. O neurocientista Daniel G. Amen (2018) diz que o córtex pré-frontal está “intimamente envolvido na concentração e no foco de atenção” (p. 206), e que quando este está comprometido, prejudica o seu desempenho. Tizuko Morchida Kishimoto (2002) defende que o brinquedo é um artefacto pertinente no crescimento e desenvolvimento da criança, e que o manipula livremente. Brougère, G. (1995) pressupõe a presença de uma função como determinante no interesse do objeto, como por exemplo, o princípio de construção (encaixe, montagem) para as peças de um jogo de construção. Friedrich Fröebel (1782-1852) em 1840 destacou o brinquedo como importante para educar as crianças na escola, e teve uma grande ideia, a de criar um brinquedo que dava para montar e desmontar, o chamado jogo de construção. O arquiteto Bruno Taut (1880-1938) diz que um brinquedo de construções é um sistema aberto que possibilita um enorme número de variações possíveis partindo dos mesmos elementos base, e que a criança aprende fazendo, e brincando, não necessitando de um ensinamento prévio. Segundo Benjamim, W. (1984), para a criança, a repetição é a “alma do jogo”. Nada a alegra mais do que o “mais uma vez”. Para demonstrar a sua validade e legitimidade começou-se por fazer o cruzamento de vários campos de estudos que constam nos capítulos 1, 2, 3, 4, 5, 6 ,7, 8 e 9 da Primeira Parte da dissertação. Desta conexão, surgiram conclusões pertinentes para o desenvolvimento e criação do artefacto de design e inclusivo proposto no âmbito da investigação em design. Para validar a pertinência do estudo, a investigadora e autora da tese desenvolveu um brinquedo de construção para a realização da atividade lúdica experimental “atenta, brinca & constrói” em contexto escolar, no Agrupamento de Escolas de Nelas (AENelas), segundo a Metodologia Projetual de Bruno Munari (1989), pelos sete Princípios do Design Inclusivo e no Design Centrado no Utilizador (DCU), que consta na Segunda Parte da tese – a Investigação Empírica. A actividade lúdica experimental “atenção, brinca & constrói”, constituída por três versões: A- livre; B – a partir de uma imagem; C - a partir de imagens e indicações, aplicada durante três sessões, foi desenvolvida por três grupos-amostra de quatro crianças com PHDA, défice de atenção, e sem dificuldades dos 2º, 3º e 4º anos, em contexto sala de aula em situação de intervenção do tipo oficina, mediada pela construção de imagens por meio da sua imaginação e por imitação (por meio de 2 Books disponibilizados e desenvolvidos para o propósito), a partir de 14 figuras geométricas que funcionam por encaixe. O objetivo da actividade foi a de verificar e validar se o brinquedo de construção lúdico-analógico desenvolvido para a realização da actividade, superava ou cumpria com o propósito a que se propôs: trabalhar/exercitar, melhorar, aumentar, manter/sustentar ou desenvolver as competências de atenção e concentração em crianças com PHDA, défice de atenção e concentração, e em crianças sem dificuldades ou necessidades educativas especiais. Os resultados obtidos fazem parte integrante da actividade lúdica experimental “atenta, brinca & constrói” e sustentam a afirmação da tese enunciada.The present research thesis in Design that will be presented, argues that the use of playful, analogical and construction artifacts, handled through geometric and fitting pieces in a school context, develop attention and concentration skills in children diagnosed with Pathology. of Attention Deficit Hyperactivity Disorder (ADHD) predominantly inattentive, between 7 and 11 years old, in childhood. The artifact, of an inclusive nature, was designed and developed in order to ensure and expedite equal opportunities by supporting success educational. It is intended to be used by the greatest number of users, in order to privilege, encourage, motivate, enable and enable all children, and to provoke pleasant moments and always of learning and with focus on the development of the attention and concentration of the child. The work is divided into two distinct parts. The first part is characterized by bibliographic research and the second by empirical research, fieldwork. The state of the art legitimizes and validates according to the DMS-5 (2014), authors such as Russell Barkley (2008), Mark Selikowitz (2010), João Lopes (2004), Luis de Miranda Correia & Vitor da Fonseca (2008), Keith Conners (2009), Nuno Lobo Antunes (2014), among other specialist authors studied from various scientific areas, that the lack of attention and in maintaining it, is the problematic nucleus of the pathology of ADHD and that it compromises the school life daily, child's family and social life. Neuroscientist Daniel G. Amen (2018) says that the prefrontal cortex is “intimately involved in the concentration and focus of attention” (p. 206), and that when it is compromised, it impairs its performance. Tizuko Morchida Kishimoto (2002) argues that the toy is a relevant artifact in the child's growth and development, and that he manipulates it freely. Brougère, G. (1995) presupposes the presence of a function as a determinant in the interest of the object, such as, for example, the construction principle (fitting, assembly) for the pieces of a construction game. Brougère, G. (1995) presupposes the presence of a function as a determinant in the interest of the object, such as, for example, the construction principle (fitting, assembly) for the pieces of a construction game. Friedrich Fröebel (1782-1852) in 1840 highlighted the toy as important for educating children at school, and had a great idea, to create a toy that could be assembled and dismantled, the so-called construction game. The architect Bruno Taut (1880-1938) says that a construction toy is an open system that allows a huge number of possible variations starting from the same basic elements, and that the child learns by doing and playing, not needing a previous teaching. According to Benjamin, W. (1984), for the child, repetition is the “soul of the game”. Nothing cheers her more than “one more time”. In order to demonstrate its validity and legitimacy, we began by crossing several fields of studies that appear in chapters 1, 2, 3, 4, 5, 6, 7, 8 and 9 of the First Part of the dissertation. From this connection, relevant conclusions emerged for the development and creation of the design and inclusive artifact proposed within the scope of design research. To validate the relevance of the study, the researcher and author of the thesis developed a construction toy to carry out the “attentive, play & build” experimental play activity in a school context, in the Nelas School Group (AENelas), according to the Design Methodology by Bruno Munari (1989), for the seven Principles of Inclusive Design and User-Centered Design (DCU), which appears in the Second Part of the thesis – Empirical Research. The experimental ludic activity “attention, play & build”, consists of three versions: A- free; B – from an image; C - from images and indications, applied during three sessions, it was developed by three sample groups of four children with ADHD, attention deficit, and without difficulties from the 2nd, 3rd and 4th grades, in a classroom context in a situation of workshop type intervention, mediated by the construction of images through your imagination and by imitation (through 2 Books made available and developed for the purpose), from 14 geometric figures that work by fitting. The objective of the activity was to verify and validate whether the playful-analog construction toy developed to carry out the activity exceeded or fulfilled the purpose for which it was proposed: work/exercise, improve, increase, maintain/sustain or develop the attention and concentration skills in children with ADHD, attention deficit and concentration, and in children without difficulties or special educational needs.Programa Doutoral em Desig

Effects of riparian plant diversity loss on detritus food webs become more pronounced at longer times

Publicado em "Symposium for European Freshwater Sciences : abstract book"We examined the potential long-term impacts of riparian plant diversity loss on diversity and activity of aquatic microbial decomposers and on the feeding behaviour and body composition of a stream invertebrate shredder. Microbial assemblages were obtained in a mixed-forest stream by immersion of mesh bags containing alder, oak and eucalyptus leaves, commonly found in riparian corridors of Iberian streams. Simulation of species loss was done in microcosms by including a set of all leaf species, retrieved from the stream, and non-colonized leaves of 3, 2 or 1 leaf species. Leaves were renewed every month throughout 6 months, and microbial inoculum was ensured by keeping a set of colonized leaves from the previous month. After 2 (short time) and 6 months (long time) of plant species loss, microbial diversity, leaf mass loss and fungal biomass were assessed in each leaf species. Leaves from all leaf treatments were used to feed invertebrate shredders. Molecular diversity of fungi and bacteria, as the total number of OTUs per leaf diversity treatment, decreased with leaf diversity loss. Fungal biomass on oak and eucalyptus leaves tended to decrease linearly with leaf species loss. Decomposition of alder and eucalyptus leaves was affected by leaf species identity, mainly after long time. Leaf decomposition of alder decreased when mixed with eucalyptus, while decomposition of eucalyptus decreased in mixtures with oak. Time led to an increase of the positive diversity effects on leaf consumption and FPOM production by the invertebrates. Regarding invertebrates’ body composition, the % of C increased and the % of N decreased when animals were fed with leaves after long time of diversity loss. Moreover, leaf identity affected invertebrates’ body composition after feeding, suggesting deviation from strict homeostasis. Results suggest that effects of leaf diversity on microbial decomposers depended on leaf species number and also on which species were lost from the system, especially after longer time. Also, leaf diversity affected leaf consumption and FPOM production by invertebrates, as well as animals’ body composition. This may have implications for the management of riparian forests to maintain stream ecosystem functioning. FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011, PTDC/AAC-AMB/113746/2009 and PTDC/AAC-AMB/117068/2010), SD (SFRH/BPD/47574/2008) and IF (SFRH/BD/42215/2007)FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011, PTDC/AAC-AMB/113746/2009 and PTDC/AAC-AMB/117068/2010), SD (SFRH/BPD/47574/2008) and IF (SFRH/BD/42215/2007

Long-term effects of riparian vegetation diversity on stream-dwelling microbes and litter decomposition

Manipulations of plant litter diversity have been shown to affect litter decomposition and to alter the structure of aquatic assemblages. However, most experiments addressing biodiversity effects have been conducted at small temporal scales. Here, we used a pool of 3 common riparian plant species in Portugal (alder, oak and eucalyptus), to examine the potential long-term impacts of riparian diversity loss on litter decomposition and associated microbes. Fine-mesh bags containing mixtures of the 3 leaf species were immersed in a mixed-forested stream to allow microbial colonization. After 2 weeks, leaves were retrieved and placed in microcosms to simulate plant species loss. For that, all combinations of 1 to 3 non-colonized leaf species were enclosed in mesh containers and a set of colonized leaves was used as inoculum. This procedure was repeated each 30 days during 6 months keeping leaf species composition constant. In every 2 months, we assessed leaf mass loss, fungal biomass and microbial diversity by the number of operational taxonomic units (OTUs) from denaturing gradient gel electrophoresis, using primers targeting rDNA for bacteria, fungi and ciliates. The highest diversity on litter was found for bacteria (68 OTUs), followed by fungi (41 OTUs) and ciliates (31 OTUs). Litter decomposition, fungal biomass and the structure of microbial assemblages on each litter species varied along time. Fungal biomass and diversity of fungi and ciliates were affected by litter species diversity. After 6 months, fungal biomass on oak and eucalyptus was highest in mixtures with 3 litter species. Also fungal diversity on each litter species was highest in leaf mixtures, especially at longer times. Results suggest that changes in riparian vegetation, at longer time scales, can alter the structure of stream microbial assemblages and affect litter decomposition dynamics in streams.I Fernandes (SFRH/BD/42215/2007) and S Duarte (SFRH/BPD/47574/2008) were supported by Fundação para a Ciência e a Tecnologia (FCT

Long-term effects of riparian-plant diversity loss on a stream invertebrate shredder

We used a pool of 3 common riparian-plant species in Portugal (alder, oak and eucalyptus) to examine the potential long-term impacts of riparian diversity loss on the feeding behaviour and body composition of a stream invertebrate shredder (Limnephilidae). Fine-mesh bags containing mixtures of the 3 leaf species were immersed in a mixed-forested stream to allow microbial colonization. After 2 weeks, colonized leaves were transferred to microcosms containing stream water and all combinations of 1 to 3 non-colonized leaf species enclosed in mesh containers. The experiment ran for 6 months. In each month, a portion of leaf material was used to inoculate new microcosms containing non -colonized leaf material, keeping the leaf species composition constant. After 2 and 6 months, those leaves were used to feed invertebrate shredders for a period of 8 days. Leaf consumption and FPOM production by the shredder were affected by leaf species diversity, with higher values in mixtures with 3 leaf species. Leaf mass loss and FPOM production were also affected by leaf species identity, but not by time of leaf diversity loss. C:N ratio of FPOM was affected by leaf identity and showed a positive linear relationship with initial leaf C:N ratio. Invertebrate C:N ratio increased along time of leaf diversity loss. Results suggest that the riparian-plant diversity loss can affect leaf consumption, FPOM production and invertebrate body composition, but effects did not appear to change at longer times.FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011, PTDC/AAC-AMB/117068/2010), IF (SFRH/BD/42215/2007) and SD (SFRH/BPD/47574/2008)Fundação para a Ciência e a Tecnologia (FCT) - PEst-C/BIA/UI4050/2011, PTDC/AAC-AMB/117068/2010, SFRH/BD/42215/2007, SFRH/BPD/47574/200

Temperature alters interspecific relationships among aquatic fungi

Temperature is a key factor in determining the structure and performance of fungal assemblages on decomposing plant litter in streams. However, little is known of how temperature affects interspecific relationships among fungi. We compared the growth of four aquatic hyphomycetes co-occurring in temperate streams, in monocultures and all species combinations when exposed to five temperatures from 11 to 27ºC. In monocultures, maximum growth rates of Heliscus submersus, Lunulospora curvula and Varicosporium elodeae occurred at 27ºC whereas Articulospora tetracladia had the lowest growth rate. At 27 ºC, the increase in species diversity had no effect on the growth of V. elodeae, increased the growth of H. submersus and L. curvula, and decreased the growth of A. tetracladia. Results suggest that within a species’ optimal temperature range the growth of that species increases with higher fungal diversity, while outside this range growth decreases with diversity.FEDER-POFC-COMPETE and the Portuguese Foundation for Science and Technology supported this study (PEst-C/BIA/UI4050/2011, PTDC/CLI/67180/2006 and PTDC/AAC-AMB/117068/2010), S. Duarte (SFRH/BPD/47574/2008) and I. Fernandes (SFRH/BD/42215/2007)

Temperature changes interspecific relationships among aquatic hyphomycetes

The Portuguese Foundation for the Science and Technology supported this work (PTDC/CLI/67180/2006), I. Fernandes (SFRH/BD/42215/2007) and S. Duarte (SFRH/BPD/47574/2008

Helicobacter pylori prophages: screening, detection, induction and potential therapeutic use

Helicobacter pylori is a microaerophilic bacterium that chronically infects the human gastric mucosa. Infections caused by this pathogen are difficult to treat, mainly due to the increased resistance of this species to conventional antibiotics. Therefore, it is important to develop antibiotic alternative or complementary approaches to tackle H. pylori infections. Bacterio(phages) have proven to be efficient antibacterial agents, however it is very difficult to isolate strictly lytic phages infecting H. pylori. Nevertheless, this bacterial species presents prophages in their genomes and although strictly lytic phages have been consensually preferred for phage therapy purposes, temperate prophages holds a great but an exploited potential. In the present work, we developed a new PCR-based screening method to detect the presence of prophages genes in a set of H. pylori Portuguese clinical strains. The genomes of selected strains were then sequenced using a combined Illumina platform and MinION nanopore-based sequencing strategy. Prophages content was then analysed using the PHASTER tool. After sequencing analysis, UV light was used to induce phages, from which one was further characterized in terms of morphology, host range, stability on an in vitro gastric model, genome analysis and efficacy against a H. pylori culture. The complementarity between Illumina and Nanopore results, allowed us to identify a total of 10 intact, 7 questionable and 47 incomplete prophages on the 14 sequenced strains. One predicted intact prophage was induced successfully, and presents a genome length of 31 162 bp with 37.1 % G+C content. Interestingly, this new podovirus infects five H. pylori strains, and in the gastric in vitro model only a small loss of phage titer was observed in the gastric phase, suggesting that this phage could be adapted to the stomach environment. Farther, this phage demonstrated to be capable of maintaining the H. pylori population at low levels for up to 24 h post-infection with MOIs of 0.01, 0.1 and 1. Overall, a new PCR screening method was developed to detect prophages on H. pylori and positive correlations with sequencing results were observed. Moreover, this new isolated phage seems to have therapeutic potential to treat H. pylori gastric infections.This work was supported by the Portuguese Foundation for Science and Technology – Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and Project PTDC/SAU-PUB/29182/2017 [POCI-01-0145-FEDER-029182]. Rute Ferreira is recipient of a FCT PhD grant with the reference SFRH/BD/146496/2019info:eu-repo/semantics/publishedVersio

Screening and in silico characterization of prophages in Helicobacter pylori genomes

Temperate bacterio(phages) play an important role on the evolution of pathogenic bacteria. Nevertheless, information on their role in Helicobacter pylori (an important gastric pathogen bacterium) is scarce. The present study developed a workflow for the identification of prophages in Portuguese H. pylori clinical strains, proposing the use of a new PCR-based screening method. The genome of strains with different PCR profiles were then sequenced. In the fourteen genomes analysed, nine intact prophages were identified by PHASTER. These prophages were annotated by analogy with other identified phages, where seven contained the integrase gene, corroborating the results obtained in the PCR screening, with only one exception. Still, in PCR screening, the holin gene was identified in 75 % of the strains containing intact phages, but BLASTp homologies only recognized this gene in one of the prophages. Fifty-six percent are podovirus, while in 44 % it was not possible to assign any family, according to the VirFam tool. Using the Resistance Gene Identifier of CARD it was identified the Acinetobacter mutant Lpx gene conferring resistance to colistin in two intact prophages. The BLASTp search identified a putative ABC binding cassette transporter in one of the intact prophages. On the bacterial genomes, 71 % have the CRISPR-Cas system classified as evidence level 1 by CRISPRCasFinder, which typically indicate potentially invalid CRISPR arrays. The use of an initial PCR screening method increased the identification of intact prophage-containing strains from 20 % to 57 %. Furthermore, the few virulence factors identified in prophages, and the possible inactivity of CRISPR-Cas in the bacterial genomes, allow the choice of strains for the isolation of phages for future studies. Overall, our results represent a significant contribution to the knowledge of prophages in H. pylori, and provide valuable insights into their potential use in phage therapy.info:eu-repo/semantics/publishedVersio