231 research outputs found
Positive solutions to find a job: cultural mismatches between companies and employees
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and EconomicsPsychology is not just the study of disease, weakness, and damage; it also is the study of strength and virtue (Seligman & Csikszentmihalyi, 2000). Attempts to change this thinking school is the theory of Positive Psychology from Seligman which is the base for this dissertation. The methodology used in our model followed the hypothesis testing in order to assess the veracity of positive behaviors affecting the outcome of finding a job. Therefore, through the use of Logistic Regressions, several results proved that positive behaviors such as optimism are indeed affecting the way we apply to a job and how satisfied we are with it. Thus, since each country presents a different set of cultural behaviors such as the level of optimism and self-determination, companies and education systems that are internationalizing should concern cultural impacts and maybe mind about cultural teachings to local workers to improve their adaptation to the institution.
The models studied in this dissertation should be tested again with different samples in order to bring more consistency to this subject
New solutions to capture and enrich bacteria from complex samples
Current solutions to diagnose bacterial infections though reliable are often time-consuming, laborious and need a specific laboratory setting. There is an unmet need for bedside accurate diagnosis of infectious diseases with a short turnaround time. Moreover, low-cost diagnostics will greatly benefit regions with poor resources. Immunoassays and molecular techniques have been used to develop highly sensitive diagnosis solutions but retaining many of the abovementioned limitations. The detection of bacteria in a biological sample can be enhanced by a previous step of capture and enrichment. This will ease the following process enabling a more sensitive detection and increasing the possibility of a conclusive identification in the downstream diagnosis. This review explores the latest developments regarding the initial steps of capture and enrichment of bacteria from complex samples with the ultimate goal of designing low cost and reliable diagnostics for bacterial infections. Some solutions use specific ligands tethered to magnetic constructs for separation under magnetic fields, microfluidic platforms and engineered nano-patterned surfaces to trap bacteria. Bulk acoustics, advection and nano-filters comprise some of the most innovative solutions for bacteria enrichment.This research is affiliated to the VibrANT project that received funding from the EU Horizon 2020 Research and Innovation Programme under the Marie Sklowdowska-Curie Grant, agreement no 765042. In addition, MGS, TC and LRR acknowledge the fnancial support from Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), through national funds and where applicable co-fnanced by the FEDER, within the PT2020 Partnership Agreement. The same authors also acknowledge BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio
A conceptual model of sprouting responses in relation to fire damage: an example with cork oak (Quercus suber L.) trees in Southern Portugal
The sprouting response types of 1,151
cork oak (Quercus suber) trees one and half years
after a wildfire in southern Portugal were characterised.
It was hypothesised that different response types
should occur according to the following conceptual
model: an increased level of damage (fire severity) on
a sprouting tree that suffered a crown fire was
expected to be reflected in a sequence of four
alternative events, namely (a) resprouting exclusively
from crown, (b) simultaneous resprouting from crown
and base, (c) resprouting exclusively from base and
(d) plant death. To assess whether the level of
expected damage was influenced by the level of
protection from disturbance, we explored the relationships
between response types and tree size, bark
thickness and cork stripping, using an informationtheoretic
approach. The more common response type
was crown resprouting (68.8% of the trees), followed
by plant death (15.8%), simultaneous resprouting
from crown and base (10.1%) and basal resprouting
(5.3%). In agreement with the conceptual model,
trees which probably suffered a higher level of
damage by fire (larger trees with thinner bark;
exploited for cork) died or resprouted exclusively from base. On the other hand, trees that were well
protected (smaller trees with thicker bark not
exploited for cork) were able to rebuild their canopy
through crown resprouting. Simultaneous resprouting
from the crown and base was determined mainly by
tree size, and it was more common in smaller tree
Design of materials to capture and enrich bacterial samples
Background: Diseases arising from pathogenic infections cause immense loss of life and illnesses
globally besides having severe negative social and economic impact. Current methods of diagnosing
such infections rely mostly on culture-based assays which are complex, time consuming and
expensive. Other related problems include low detection limits of diagnostic methods, thus requiring
methods to concentrate and enrich the samples being analysed.
Objectives: It is imperative that novel diagnostic methods which are simple, accurate, quick and costeffective are developed. An approach to develop such a diagnostic platform is by including an
enrichment step to concentrate the microorganisms present in the biological samples and then the
detection of specific pathogens.
Methods: To capture and concentrate bacteria from samples, collagen nanoparticles were
synthesised and then incubated with those samples. Collagen binds to bacteria leading to enrichment
upon elution. In addition, magnetic particles were added to the collagen nanoparticles in order to
facilitate the recovery of the nanoparticles from the samples.
After enrichment of a given sample a specific detection method utilizing voltammetric biosensors
was used. Electrodes to be used can also be functionalised to specifically capture bacteria and avoid
the adhesion of unspecific molecules to the electrode which could affect the accuracy of the readout.
Results: Bacteria bind to the collagen-magnetic nanoparticles and these nanoparticles can be
recovered using a magnetic field.
Polypropylene - which is the substrate being used for the electrodes construction was
functionalised by physical treatments including plasma, UV and ozone to ultimately produce an antiadhesive surface.info:eu-repo/semantics/publishedVersio
Cabido Metropolitano e Primacial de Braga : reabilitação e ampliação do Tesouro-Museu da Catedral de Braga - Arte Sacra: intervenção arqueológica (demolições, sondagens e acompanhamento) realizada na área dos edifícios n.ºs 102/118 da rua D. Diogo de Sousa (2003-2004) : relatório
O “Cabido Metropolitano e Primacial de Braga”, entidade proprietária dos edifícios situados no gaveto da rua D. Diogo de Sousa (nº 102 a 118) com a rua do Cabido- ver carta militar 1:25 000 (fig. 1) e carta de Braga de 1968 à escala 1:1 000 (fig. 2), levou a efeito a construção de um edifício com fins museológicos naquele espaço, no âmbito do projecto: “Reabilitação e Ampliação do Tesouro-Museu da Catedral de Braga – Arte Sacra”, da autoria do gabinete de rquitectura- “Humberto Vieira, Arquitecto, Lda”.
Dado que a área em causa se insere em pleno Centro Histórico, e que o edificado
inclui a construção de cave e o consequente rebaixamento do solo, o IPPAR, para além
de condicionar a demolição dos muros com algum significado histórico urbano,
condicionou ainda a elaboração de qualquer projecto, à realização prévia de sondagens
arqueológicas no local. Assim, os responsáveis do Cabido contactaram a Unidade de Arqueologia da Universidade do Minho, entidade responsável pelo projecto científico de Bracara Augusta, com vista ao acompanhamento das demolições e à realização dos indispensáveis trabalhos arqueológicos, solicitação que foi aceite, após aprovação de um orçamento para o efeito
Novel biorecognition elements against pathogens in the design of state-of-the-art diagnostics
Infectious agents, especially bacteria and viruses, account for a vast number of hospitalisations and mortality worldwide. Providing effective and timely diagnostics for the multiplicity of infectious diseases is challenging. Conventional diagnostic solutions, although technologically advanced, are highly complex and often inaccessible in resource-limited settings. An alternative strategy involves convenient rapid diagnostics which can be easily administered at the point-of-care (POC) and at low cost without sacrificing reliability. Biosensors and other rapid POC diagnostic tools which require biorecognition elements to precisely identify the causative pathogen are being developed. The effectiveness of these devices is highly dependent on their biorecognition capabilities. Naturally occurring biorecognition elements include antibodies, bacteriophages and enzymes. Recently, modified molecules such as DNAzymes, peptide nucleic acids and molecules which suffer a selective screening like aptamers and peptides are gaining interest for their biorecognition capabilities and other advantages over purely natural ones, such as robustness and lower production costs. Antimicrobials with a broad-spectrum activity against pathogens, such as antibiotics, are also used in dual diagnostic and therapeutic strategies. Other successful pathogen identification strategies use chemical ligands, molecularly imprinted polymers and Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease. Herein, the latest developments regarding biorecognition elements and strategies to use them in the design of new biosensors for pathogens detection are reviewed.This research is affiliated with the VibrANT project that received funding from the EU
Horizon 2020 Research and Innovation Programme under the Marie Sklowdowska-Curie Grant,
agreement no 765042. In addition, the authors acknowledge the financial support from Fundação
para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2020
unit. Débora Ferreira (DF) is the recipient of a fellowship supported by a doctoral advanced training
(call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020.info:eu-repo/semantics/publishedVersio
Electrochemical Aptasensor for the Detection of the Key Virulence Factor YadA of Yersinia enterocolitica
New point-of-care (POC) diagnosis of bacterial infections are imperative to overcome the deficiencies of conventional methods, such as culture and molecular methods. In this study, we identified new aptamers that bind to the virulence factor Yersinia adhesin A (YadA) of Yersinia enterocolitica using cell-systematic evolution of ligands by exponential enrichment (cell-SELEX). Escherichia coli expressing YadA on the cell surface was used as a target cell. After eight cycles of selection, the final aptamer pool was sequenced by high throughput sequencing using the Illumina Novaseq platform. The sequencing data, analyzed using the Geneious software, was aligned, filtered and demultiplexed to obtain the key nucleotides possibly involved in the target binding. The most promising aptamer candidate, Apt1, bound specifically to YadA with a dissociation constant (Kd) of 11 nM. Apt1 was used to develop a simple electrochemical biosensor with a two-step, label-free design towards the detection of YadA. The sensor surface modifications and its ability to bind successfully and stably to YadA were confirmed by cyclic voltammetry, impedance spectroscopy and square wave voltammetry. The biosensor enabled the detection of YadA in a linear range between 7.0 × 104 and 7.0 × 107 CFU mL−1 and showed a square correlation coefficient >0.99. The standard deviation and the limit of detection was ~2.5% and 7.0 × 104 CFU mL−1, respectively. Overall, the results suggest that this novel biosensor incorporating Apt1 can potentially be used as a sensitive POC detection system to aid the diagnosis of Y. enterocolitica infections. Furthermore, this simple yet innovative approach could be replicated to select aptamers for other (bacterial) targets and to develop the corresponding biosensors for their detection.This research is affiliated with the VibrANT project that received funding from the EU Horizon 2020 Research and Innovation Programme under the Marie Sklowdowska-Curie Grant, agreement no 765042. In addition, the authors acknowledge the financial support from Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and of LABBELS—Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio
Electrochemical Aptasensor for the Detection of the Key Virulence Factor YadA of Yersinia enterocolitica
New point-of-care (POC) diagnosis of bacterial infections are imperative to overcome the deficiencies of conventional methods, such as culture and molecular methods. In this study, we identified new aptamers that bind to the virulence factor Yersinia adhesin A (YadA) of Yersinia enterocolitica using cell-systematic evolution of ligands by exponential enrichment (cell-SELEX). Escherichia coli expressing YadA on the cell surface was used as a target cell. After eight cycles of selection, the final aptamer pool was sequenced by high throughput sequencing using the Illumina Novaseq platform. The sequencing data, analyzed using the Geneious software, was aligned, filtered and demultiplexed to obtain the key nucleotides possibly involved in the target binding. The most promising aptamer candidate, Apt1, bound specifically to YadA with a dissociation constant (Kd) of 11 nM. Apt1 was used to develop a simple electrochemical biosensor with a two-step, label-free design towards the detection of YadA. The sensor surface modifications and its ability to bind successfully and stably to YadA were confirmed by cyclic voltammetry, impedance spectroscopy and square wave voltammetry. The biosensor enabled the detection of YadA in a linear range between 7.0 × 104 and 7.0 × 107 CFU mL−1 and showed a square correlation coefficient >0.99. The standard deviation and the limit of detection was ~2.5% and 7.0 × 104 CFU mL−1, respectively. Overall, the results suggest that this novel biosensor incorporating Apt1 can potentially be used as a sensitive POC detection system to aid the diagnosis of Y. enterocolitica infections. Furthermore, this simple yet innovative approach could be replicated to select aptamers for other (bacterial) targets and to develop the corresponding biosensors for their detection.This research is affiliated with the VibrANT project that received funding from the EU Horizon 2020 Research and Innovation Programme under the Marie Sklowdowska-Curie Grant, agreement no 765042. In addition, the authors acknowledge the financial support from Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and of LABBELS—Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio
Collagen-coated magnetic nanoparticles to capture pathogens from biological samples
Conventional methods of diagnosing bacterial infections such as microbial culture and molecular techniques, while highly sensitive, rely on expensive equipment and highly skilled operators. There is a need for affordable and portable diagnostic systems which are simple to operate while preserving reliability. Pre-enrichment of bacteria present in a sample coupled with subsequent bacterial identification steps can serve as a simple yet effective diagnostic technique. Magnetic nanoparticles (MNPs) coated with collagen were used to demonstrate enrichment of E.coli recombinantly expressing adhesins YadA and UspA2 since these adhesins are known to target and adhere to host collagen. The MNPs were synthesized chemically and characterized by Fourier transform infrared spectroscopy and Dynamic light scattering and the most stable MNPs were selected. Adhesion assays were performed together with fluorescent microscopy imaging to assess the pre-enrichment of bacteria by the collagen MNPs. Capture of bacteria by the collagen MNPs was successfully observed and capture efficiency of the collagen MNPs for E.coli YadA and E.coli UspA2 was calculated to be 50% and 68% respectively.VibrANT H2020-MSCA-ITN-2017, agreement no. 765042. FCT UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004).info:eu-repo/semantics/publishedVersio
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