Papers by Helena Carvalho
Brazilian Journal of Health and Biomedical Sciences, 2021
Introduction: As the COVID-19 pandemic progresses aroundthe world, the universal use of face mask... more Introduction: As the COVID-19 pandemic progresses aroundthe world, the universal use of face masks imposes itself as ameasure to mitigate the transmission of SARS-CoV-2 and iscurrently recommended by the World Health Organization.However, its effectiveness as a method of preventing COVID-19 is still controversial. Objective: To review the literatureon the universal use of facial masks, including fabric ones, andtheir recommendations for use. Methods: Narrative reviewof published studies on the topic. Results: Face masks act predominantlyas a source control mechanism, as they capturethe droplets expelled by the user when speaking, coughingor sneezing, protecting other people and the environmentfrom contamination by potentially infecting droplets. Evidenceof the effectiveness of its universal use as a method ofmitigating epidemics of viral respiratory infections is derivedfrom experimental studies and mathematical models. Properuse of facial masks is essential to ensure their effectiv...
Revista Hospital Universitário Pedro Ernesto, 2014
Physiology has traditionally been a difficult subject to teach because student success relies on ... more Physiology has traditionally been a difficult subject to teach because student success relies on conceptual understanding more than memorization of facts. The use of engaging instructional methods, such as manipulative models, dramatizations, and interactive computer programs not only helps to maintain students' attention but also to enhance learning and understanding. Here we present an active learning activity for use in renal physiology education. The activity utilizes a manipulative model of the nephron that is inexpensive and simple to construct. Working in small groups, students were asked to apply their knowledge by identifying the correct placement of various transporters and ion channels along the various segments of the nephron. The activity provides students with the opportunity to model and understand the relative changes in concentrations of various filtered solutes as they move through the nephron. The hands-on portion of the activity is paired with didactic explanations of key concepts and intermittent large-group debriefs the keep all students focused and address questions. Overall, the manipulative serves as a unique teaching tool that may be adapted for use in a wide variety of classroom settings. In our experience, the manipulative helped students identify gaps in knowledge and enhance their understanding of nephron physiology while having fun learning alongside their classmates.
Revista Hospital Universitário Pedro Ernesto, 2014
As an educator, have you ever wondered why the students in the classroom learn so little despite ... more As an educator, have you ever wondered why the students in the classroom learn so little despite the innumerable hours you have spent perfecting the lecture? Why, after a brief period of time, do students start losing attention and focus? Many lecturers have experienced this phenomenon, some more than others. To address this issue, in the setting of a fifty minute lecture we've included several demonstrations involving volunteer students and/or economical home created models. Several anatomical concepts, such as the configuration of pleura and thoracic structures and peritoneum and abdominal/pelvic structures, were demonstrated in the classroom using transparent plastic sheets and sleeves, cardboard boxes, plastic bottles and balloons, and often even the students themselves. Such activity was designed to spike the students' curiosity, involvement, interest, and engagement for the length of the fifty minute lecture. These changes were implemented over several lectures during each eight week academic block, and the lectures with such demonstrations were interspersed between other traditional didactic lectures. To our satisfaction, not only did such non-traditional lecturing appear to help the students understand and learn better, but there was better attendance in these non-mandatory lectures, coupled with great enthusiasm, attention, and engagement during the lectures. Our goal in the classroom was to create an environment that helps students to learn effectively. This article presents a teaching approach that engages students by making them part of a classroom activity, which attracts the students' attention and invokes their curiosity with inexpensive home-made anatomy models.
Revista Hospital Universitário Pedro Ernesto, 2014
Implementing the flipped classroom Implementando a sala de aula invertida La implementacion de la... more Implementing the flipped classroom Implementando a sala de aula invertida La implementacion de la clase invertida
Journal of Education and Training Studies, 2016
Part of the educator's mission is to develop new methodologies that promote active learning. This... more Part of the educator's mission is to develop new methodologies that promote active learning. This study examines the use of dramatization of the cardiac cycle in medical school. Two groups (n=42, 21 each) of first-year medical students participated. Group A was initially taught through dramatization alone, while Group B was taught through lecture followed by dramatization. Students completed a 13-item assessment (pretest and posttest) designed to measure knowledge of the cardiac system immediately before and after participating in the dramatization activity. Six months later students completed a third posttest assessment (follow-up) to assess their retention of cardiac cycle content. Students also rated their prior knowledge of general physiology and their confidence level in learning the material presented. Students in groups A and B scored at the same approximate level on the initial pretest (57% and 61% respectively, p=0.53). Scores for both groups increased significantly on the immediate posttest compared to pretest (p<0.0001). Both groups scored equally well on the immediate posttest (88% and 89% respectively, p=0.48), even though Group A had been taught the content based on dramatization alone. Both groups subsequently scored equally well on the six-month follow-up assessment (p<0.0001). Levels of self-reported confidence in knowledge also increased in both groups (p<0.05). This interactive teaching method increases student confidence in their knowledge and promotes learning in the short term equally well when compared to more traditional teaching methods. Implications for further research on dramatization as a teaching method are explored.
In a global market, companies must deal with a high rate of changes in business environment. Most... more In a global market, companies must deal with a high rate of changes in business environment. Most manufacturing systems fail to sustain productivity when process disturbances occur. Therefore, it is necessary to create resilient production systems with the ability to return, rapidly, to the initial stage or to an improved one. The parameters, variables and restrictions of the production system
ABSTRACT To achieve business sustainability, companies must perform a set of changes not only in ... more ABSTRACT To achieve business sustainability, companies must perform a set of changes not only in their internal processes but also in the large-scale level of business ecosystems. This change of paradigm from individual to macro level requires an understanding of new drivers of innovation as a way to improve and look for new business dynamics, to minimize the negative environmental externalities, and to keep the economic performance of companies. This chapter book focus on recent developments and future trends of eco-innovation in theory and application from its usual forms of incremental to more radical and systematic innovation. A brief introduction of eco-innovation and a terminological foundation consisting of adequate definitions of specific or ambiguous terms are given. It illustrates how models and frameworks for eco-innovation and its applications can support the ecological business modernization and how it can promote win-win situations among the different stakeholders.
The main objective of this exploratory paper is to investigate the relationships between green pr... more The main objective of this exploratory paper is to investigate the relationships between green practices of supply chain management and supply chain performance. This relationship is investigated in the context of the automotive industry. Five research propositions are suggested and tested with empirical data derived from five case studies taken from the Portuguese automotive supply chain. The data analysis identifies the most important green practices considered by managers, as well as the performance measures that are most appropriate and most widely used as means to evaluate the influence of green practices on supply chain performance. A conceptual model was derived from the data analysis and it can be used to assess the influence of green practices on supply chain performance. This model provides evidence as to which green practices have positive effects on quality, customer satisfaction and efficiency. It also identifies the practices which have negative effects on supply chain performance.
Educacao e Pesquisa, 2009
... Madalena Ramos; Helena Carvalho. ... usefulness attributed to it as a component of the rela... more ... Madalena Ramos; Helena Carvalho. ... usefulness attributed to it as a component of the relationship established with the discipline and, consequently, as a structuring factor of representations has been a topic analyzed in numerous studies (Fennema; Sherman, 1977; ...
Journal of Cleaner Production, 2013
Purpose -The purpose of this paper is to suggest an Index entitled GResilient Index to assess the... more Purpose -The purpose of this paper is to suggest an Index entitled GResilient Index to assess the greenness and resilience of the automotive companies and corresponding supply chain.
International Journal of Retail & Distribution Management, 2012
Purpose – The purpose of this paper is to explore the deployment of RFID technology in fashion su... more Purpose – The purpose of this paper is to explore the deployment of RFID technology in fashion supply chain management (FSCM). It highlights the contribution of RFID to FSCM, supporting faster logistics activities, with greater products quality, cheaper and with more responsiveness, improving customer satisfaction. Design/methodology/approach – An inductive theory building approach is used to develop a conceptual model for
International Journal of Lean Six Sigma, 2011
Purpose – This paper aims to explore the divergences and commitments between the lean, agile, res... more Purpose – This paper aims to explore the divergences and commitments between the lean, agile, resilient and green paradigms while investigating the effect of paradigms&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27; practices within supply chain attributes. Design/methodology/approach – A conceptual model with lean, agile, resilient and green practices and supply chain management attributes is proposed. Causal diagrams were used to represent the relationships between paradigm practices
International Journal of Business Performance and Supply Chain Modelling, 2010
Page 1. 304 Int. J. Business Performance and Supply Chain Modelling, Vol. 2, Nos. 3/4, 2010 Copyr... more Page 1. 304 Int. J. Business Performance and Supply Chain Modelling, Vol. 2, Nos. 3/4, 2010 Copyright © 2010 Inderscience Enterprises Ltd. Supply chain performance management: lean and green paradigms Helena Carvalho* ...
Frontiers in Plant Science, 2015
Glutamine synthetase (GS) catalyzes the first step at which nitrogen is brought into cellular met... more Glutamine synthetase (GS) catalyzes the first step at which nitrogen is brought into cellular metabolism and is also involved in the reassimilation of ammonium released by a number of metabolic pathways. Due to its unique position in plant nitrogen metabolism, GS plays essential roles in all aspects of plant development, from germination to senescence, and is a key component of nitrogen use efficiency (NUE) and plant yield. Understanding the mechanisms regulating GS activity is therefore of utmost importance and a great effort has been dedicated to understand how GS is regulated in different plant species. The present review summarizes exciting recent developments concerning the structure and regulation of GS isoenzymes, using the model legume Medicago truncatula. These include the understanding of the structural determinants of both the cytosolic and plastid located isoenzymes, the existence of a seed-specific GS gene unique to M. truncatula and closely related species and the discovery that GS isoenzymes are regulated by nitric oxide at the post-translational level. The data is discussed and integrated with the potential roles of the distinct GS isoenzymes within the whole plant context.
Brazilian Journal of Medical and Biological Research, 2010
The effectiveness of the caspase-9-based artificial &amp;amp;amp;amp;quot;death switch&am... more The effectiveness of the caspase-9-based artificial &amp;amp;amp;amp;quot;death switch&amp;amp;amp;amp;quot; as a safety measure for gene therapy based on the erythropoietin (Epo) hormone was tested in vitro and in vivo using the chemical inducer of dimerization, AP20187. Plasmids encoding the dimeric murine Epo, the tetracycline-controlled transactivator and inducible caspase 9 (ptet-mEpoD, ptet-tTAk and pSH1/Sn-E-Fv&amp;amp;amp;amp;#39;-Fvls-casp9-E, respectively) were used in this study. AP20187 induced apoptosis of iCasp9-modified C2C12 myoblasts. In vivo, two groups of male C57BI/6 mice, 8-12 weeks old, were injected intramuscularly with 5 microg/50 g ptet-mEpoD and 0.5 microg/50 g ptet-tTAk. There were 20 animals in group 1 and 36 animals in group 2. Animals from group 2 were also injected with the 6 microg/50 g iCasp9 plasmid. Seventy percent of the animals showed an increase in hematocrit of more than 65% for more than 15 weeks. AP20187 administration significantly reduced hematocrit and plasma Epo levels in 30% of the animals belonging to group 2. TUNEL-positive cells were detected in the muscle of at least 50% of the animals treated with AP20187. Doxycycline administration was efficient in controlling Epo secretion in both groups. We conclude that inducible caspase 9 did not interfere with gene transfer, gene expression or tetracycline control and may be used as a safety mechanism for gene therapy. However, more studies are necessary to improve the efficacy of this technique, for example, the use of lentivirus vector.
International Journal of Agile Systems and Management, 2013
This paper proposes a composite index, called the 'AR index', to assess the agility and resilienc... more This paper proposes a composite index, called the 'AR index', to assess the agility and resilience of automotive companies and their respective supply chains. As a first step, a model to support the AR index is developed. Next, an AR index for the automotive supply chain is suggested using a set of relevant agile and resilient supply chain practices. The Delphi technique was used to obtain a series of weights for those practices. Finally, a case study approach is used to illustrate the application of the AR index. This study represents an original approach that suggests a unique composite indicator for the agile and resilient paradigms in the context of automotive supply chains.
Plant Molecular Biology, 1997
We have cloned and sequenced the cDNAs corresponding to the two cytosolic glutamine synthetase (G... more We have cloned and sequenced the cDNAs corresponding to the two cytosolic glutamine synthetase (GS) polypeptides (a and b) of Medicago truncatula. Using these two cDNAs we have prepared a construct encoding the N-terminal domain of b and the C-terminal domain of a in order to produce a domain-swapped polypeptide which should assemble to give an enzyme containing chimeric active sites. Both the native and the domain-swapped enzymes were expressed in Escherichia coli where they were catalytically and physiologically active as they were able to rescue a glnA deletion mutant. The expressed polypeptides were of the correct size and the isoenzymes behaved similarly to their native homologues on ion-exchange chromatography. We have found slight differences in the kinetic properties of the purified enzymes and in the modulation of their activities by several putative cellular effectors. In vitro dissociation of the purified a and b homo-octamers, followed by reassociation, showed that the subunits are able to self-assemble, perhaps randomly, to form heteromeric isoenzymes. Moreover, heteromeric isoenzymes occur in the plant as revealed by studies on the GS isoenzymes of nodules, roots, stems and stipules.
Plant Molecular Biology, 2000
In this paper we have studied the localisation of expression of the two functional cytosolic glut... more In this paper we have studied the localisation of expression of the two functional cytosolic glutamine synthetase (GS) genes, MtGSa and MtGSb, in root nodules of the model legume Medicago truncatula. We have used a combination of different techniques, including immunocytochemistry, in situ hybridisation and promoter β-glucuronidase (GUS) fusions in transgenic plants, to provide the means of correlating gene expression with protein localisation. These studies revealed that transcriptional regulation (mRNA synthesis) plays an important part in controlling GS protein levels in nodules of M. truncatula. The major locations of cytosolic GS mRNA and protein are the central tissue, the parenchyma and the pericycle of the vascular bundles. These findings indicate that in nodules, GS might be involved in other physiological processes in addition to the primary assimilation of ammonia released by the bacterial nitrogenase. The two genes show different but overlapping patterns of expression with MtGSa being the major gene expressed in the infected cells of the nodule. Promoter fragments of 2.6 kb and 3.1 kb of MtGSa and MtGSb, respectively, have been sequenced and primer extension revealed that the MtGSb promoter is expressed in nodules from an additional start site that is not used in roots. Generally these fragments in the homologous transgenic system were sufficient to drive GUS expression in almost all the tissues and cell types where GS proteins and transcripts are located except that the MtGSa promoter fragment did not express GUS highly in the nodule infected cells. These results indicate that the cis-acting regulatory elements responsible for infected-cell expression are missing from the MtGSa promoter fragment.
Higher Education, 2011
A number of studies have concluded that when students have greater confidence about their math sk... more A number of studies have concluded that when students have greater confidence about their math skills and are aware of its usefulness, they have a more positive perception of the subject. This article aims to examine whether this pseudo linear trend in the relationship between affective and instrumental dimensions is also true of the university context. Special attention is devoted to the articulation of these dimensions in structuring student perceptions of quantitative methods so as to identify the various forms that this interaction can assume. Our second aim is to understand how the perceptions of these subjects are constructed by students from degree courses in distinct scientific areas. Can we speak of group dynamics whereby socialization within each degree course triggers the sharing of similar perceptions? We concluded that a certain linear trend can also be identified in the university context in the relationship between the affective dimension and usefulness of quantitative methods i.e., that the highest levels in the perception of the usefulness of these subjects corresponded to the highest levels of self confidence and enjoyment of the subjects. However, in addition to this scenario there is another configuration in which negative feelings coexist with the recognition of the usefulness of quantitative methods subjects. Namely, lower levels of self confidence and enjoyment of these subjects can also be associated with high levels of perceived usefulness. We also concluded that there is evidence of what we designated a certain course culture in the perceptions about quantitative methods. Nevertheless, when our observation is extended to the scientific area the heterogeneity of the perceptions becomes evident. Another important finding is the rejection of the thesis, at least in the university context, that defends the lack of self-confidence in quantitative methods among females student.
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Papers by Helena Carvalho