4,987 research outputs found
Brazilian Portuguese as a community language: the training journey of a teacher in London
The increase in the number of Brazilian emigrants in the last thirty or so years has led to the development of the teaching of Brazilian Portuguese as a community language abroad. In other words, this type of teaching is new and, consequently, the teachers working in community schools tend to have been trained only to work with monolingual pupils in Brazil. In this article, we reflect on the experience of one of these teachers and who works with intermediate and upper-intermediate pupils aged 11 to 15 in London. The class that caters for this group of learners was initially created with the aim of preparing them to take mainstream examinations, i.e. GCSE and A-levels in Portuguese. In this article, we describe the contextual background for these lessons and contrast it to the teacher’s expectations of teaching in this context. We then consider the few teaching courses available for teachers of Portuguese as a community language in London. Anderson’s (2008) perceived 8-strand professional development needs of community language teachers are used as a framework for analysing the experience of this Brazilian teacher. We acknowledge the positive impact of these courses on teacher knowledge and practices and call for more of these initiatives
Translational signatures and mRNA levels are highly correlated in human stably expressed genes
BACKGROUND: Gene expression is one of the most relevant biological processes of living cells. Due to the relative small population sizes, it is predicted that human gene sequences are not strongly influenced by selection towards expression efficiency. One of the major problems in estimating to what extent gene characteristics can be selected to maximize expression efficiency is the wide variation that exists in RNA and protein levels among physiological states and different tissues. Analyses of datasets of stably expressed genes (i.e. with consistent expression between physiological states and tissues) would provide more accurate and reliable measurements of associations between variations of a specific gene characteristic and expression, and how distinct gene features work to optimize gene expression. RESULTS: Using a dataset of human genes with consistent expression between physiological states we selected gene sequence signatures related to translation that can predict about 42% of mRNA variation. The prediction can be increased to 51% when selecting genes that are stably expressed in more than 1 tissue. These genes are enriched for translation and ribosome biosynthesis processes and have higher translation efficiency scores, smaller coding sequences and 3(′) UTR sizes and lower folding energies when compared to other datasets. Additionally, the amino acid frequencies weighted by expression showed higher correlations with isoacceptor tRNA gene copy number, and smaller absolute correlation values with biosynthetic costs. CONCLUSION: Our results indicate that human gene sequence characteristics related to transcription and translation processes can co-evolve in an integrated manner in order to optimize gene expression
Effect of solar cycle 23 in foF2 trend estimation
The effect of including solar cycle 23 in foF2 trend estimation is assessed using experimental values for Slough (51.5°N, 359.4°E) and Kokobunji (35.7°N, 139.5°E), and values obtained from two models: (1) the Sheffield University Plasmasphere-Ionosphere model, SUPIM, and (2) the International Reference Ionosphere, IRI. The dominant influence on the F2 layer is solar extreme ultraviolet (EUV) radiation, evinced by the almost 90% variance of its parameters explained by solar EUV proxies such as the solar activity indices Rz and F10.7. This makes necessary to filter out solar activity effects prior to long-term trend estimation. Solar cycle 23 seems to have had an EUV emission different from that deduced from traditional solar EUV proxies. During maximum and descending phase of the cycle, Rz and F10.7 seem to underestimate EUV solar radiation, while during minimum, they overestimate EUV levels. Including this solar cycle in trend estimations then, and using traditional filtering techniques, may induce some spurious results. In the present work, filtering is done in the usual way considering the residuals of the linear regression between foF2 and F10.7, for both experimental and modeled values. foF2 trends become less negative as we include years after 2000, since foF2 systematically exceeds the values predicted by a linear fit between foF2 and F10.7. Trends become more negative again when solar cycle 23 minimum is included, since for this period, foF2 is systematically lower than values predicted by the linear fit. foF2 trends assessed with modeled foF2 values are less strong than those obtained with experimental foF2 values and more stable as solar cycle 23 is included in the trend estimation. Modeled trends may be thought of as a ‘zero level’ trend due to the assumptions made in the process of trend estimation considering also that we are not dealing with ideal conditions or infinite time series.Fil: Elias, Ana Georgina. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Haro Barbás, Blas F.. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; ArgentinaFil: Shibasaki, Kiyoto . Nobeyama Solar Radio Observatory; JapónFil: Souza, Jonas R.. Centro de Previsao de Tempo E Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasi
On Lattice Constructions D and D' from q-ary Linear Codes
Multilevel lattice codes, such as the associated to Constructions ,
\overline{\mbox{D}}, D and D', have relevant applications in communications.
In this paper, we investigate some properties of lattices obtained via
Constructions D and D' from -ary linear codes. Connections with Construction
A, generator matrix, expressions and bounds for volume and minimum distances
are derived. Extensions of previous results regarding construction and decoding
of binary and -ary linear codes ( prime) are also presented
Anti-EGFR therapy: strategies in head and neck squamous cell carcinoma.
Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor that activates downstream signaling pathways, including the Ras-MEK-Erk and PI3K-AKT pathways, leading to cell proliferation, resistance to apoptosis, angiogenesis and the ability to metastasize. EGFR overexpression is a significant finding in cancer, particularly in head and neck cancer, where it is also associated with a poor prognosis. In recent years, several molecules have been designed to inhibit EGFR activation. Among the many available anti-EGFR drugs, only cetuximab was approved for the treatment of head and neck cancers. However, no predictive biomarkers of cetuximab response are currently known. In the present review, we provide an updated assessment of EGFR biology and its clinical impact in head and neck cancers. A special emphasis is placed on novel patents of EGFR-inhibitors that are anticipated to diversify the anti-EGFR therapies available to treat head and neck cancers. In particular, we outline a new class of irreversible multi-target inhibitors (e.g. afatinib, icotinib, CUDC-101), which may significantly contribute to new head and neck cancer therapies.The authors would like to acknowledge Dr. Laura Mussel
white for critical revision of the manuscript. André L. Carvalho
and Rui M. Reis have a National Counsel of Technological
and Scientific Development (CNPq) scholarship.
A.C.C, has a FAPESP (2013/13834-7) scholarship.info:eu-repo/semantics/publishedVersio
Genomic and evolutionary comparisons of diazotrophic and pathogenic bacteria of the order Rhizobiales
<p>Abstract</p> <p>Background</p> <p>Species belonging to the Rhizobiales are intriguing and extensively researched for including both bacteria with the ability to fix nitrogen when in symbiosis with leguminous plants and pathogenic bacteria to animals and plants. Similarities between the strategies adopted by pathogenic and symbiotic Rhizobiales have been described, as well as high variability related to events of horizontal gene transfer. Although it is well known that chromosomal rearrangements, mutations and horizontal gene transfer influence the dynamics of bacterial genomes, in Rhizobiales, the scenario that determine pathogenic or symbiotic lifestyle are not clear and there are very few studies of comparative genomic between these classes of prokaryotic microorganisms trying to delineate the evolutionary characterization of symbiosis and pathogenesis.</p> <p>Results</p> <p>Non-symbiotic nitrogen-fixing bacteria and bacteria involved in bioremediation closer to symbionts and pathogens in study may assist in the origin and ancestry genes and the gene flow occurring in Rhizobiales. The genomic comparisons of 19 species of Rhizobiales, including nitrogen-fixing, bioremediators and pathogens resulted in 33 common clusters to biological nitrogen fixation and pathogenesis, 15 clusters exclusive to all nitrogen-fixing bacteria and bacteria involved in bioremediation, 13 clusters found in only some nitrogen-fixing and bioremediation bacteria, 01 cluster exclusive to some symbionts, and 01 cluster found only in some pathogens analyzed. In BBH performed to all strains studied, 77 common genes were obtained, 17 of which were related to biological nitrogen fixation and pathogenesis. Phylogenetic reconstructions for Fix, Nif, Nod, Vir, and Trb showed possible horizontal gene transfer events, grouping species of different phenotypes.</p> <p>Conclusions</p> <p>The presence of symbiotic and virulence genes in both pathogens and symbionts does not seem to be the only determinant factor for lifestyle evolution in these microorganisms, although they may act in common stages of host infection. The phylogenetic analysis for many distinct operons involved in these processes emphasizes the relevance of horizontal gene transfer events in the symbiotic and pathogenic similarity.</p
Recent developments on the thermal properties, stability and applications of nanofluids in machining, solar energy and biomedicine
In this review work, the recent progress made in the use of nanofluids (NFs) applied in
three specific areas will be presented: machining, solar energy, and biomedical engineering. Within
this context, the discussions will be guided by emphasizing the thermal and stability properties of
these fluids. In machining, NFs play a prominent role in the processes of turning, milling, drilling,
and grinding, being responsible for their optimization as well as improving the useful life of the tools
and reducing costs. In the solar energy field, NFs have been used in the thermal management of the
panels, controlling and homogenizing the operating temperature of these systems. In the biomedical
area, the advantages of using NFs come from the treatment of cancer cells, the development of
vaccines before the improvement of diagnostic imaging, and many others. In all lines of research
mentioned in this study, the main parameters that have limited or encouraged the use of these fluids
are also identified and debated. Finally, the discussions presented in this review will inspire and
guide researchers in developing new techniques to improve the applications of NFs in several fields.This research was partially funded by the Portuguese national funds of FCT/MCTES
(PIDDAC) through the base funding from the following research units: UIDB/00690/2020 (CIMO),
UIDB/04077/2020 (MEtRICs), and UIDB/00532/2020 (CEFT). The authors are also grateful for
the funding of ANI and CIMO through the projects POCI-01-02B7-FEDER-069844 and CMFPE3-
EXPL2021CIMO_01, respectively. The authors also acknowledge partial financial support from the
project NORTE-01-0145-FEDER-030171 (PTDC/EMD-EMD/30171/2017), PTDC/EME-TED/7801/
2020 and EXPL/EME-EME/0732/2021 funded by the NORTE 2020 Portugal Regional Operational
Programme, under the PORTUGAL 2020 Partnership Agreement, through the European Regional
Development Fund (FEDER) and by Fundação para a Ciência e Tecnologia (FCT).info:eu-repo/semantics/publishedVersio
Is Urinary Density An Adequate Predictor Of Urinary Osmolality?
Background: Urinary density (UD) has been routinely used for decades as a surrogate marker for urine osmolality (U-osm). We asked if UD can accurately estimate U-osm both in healthy subjects and in different clinical scenarios of kidney disease. Methods: UD was assessed by refractometry. U-osm was measured by freezing point depression in spot urines obtained from healthy volunteers (N = 97) and in 319 inpatients with acute kidney injury (N = 95), primary glomerulophaties (N = 118) or chronic kidney disease (N = 106). Results: UD and U-osm correlated in all groups (p < 0.05). However, a wide range of U-osm values was associated with each UD value. When UD was <= 1.010, 28.4% of samples had U-osm above 350 mOsm/kg. Conversely, in 61.6% of samples with UD above 1.020, U-osm was below 600 mOsm/kg. As expected, U-osm exhibited a strong relationship with serum creatinine (S-creat), whereas a much weaker correlation was found between UD and Screat. Conclusion: We found that UD is not a substitute for U-osm. Although UD was significantly correlated with U-osm, the wide dispersion makes it impossible to use UD as a dependable clinical estimate of U-osm. Evaluation of the renal concentrating ability should be based on direct determination of U-osm.1
Chitosan composites in packaging industry-current trends and future challenges
This work has been supported by FCT-Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UID/EMS/04077/2019 and UIDP/04077/2020. This work has also been supported by the Associate Laboratory for Green Chemistry-LAQV which is financed by national funds from FCT/MCTES (UID/QUI/50006/2019 and UIDB/50006/2020).Chitosan-based composites play an important role in food packaging applications and can be used either as films or as edible coatings. Due to their high costs and lower performance (i.e., lower barrier against water vapor, thermal, and mechanical properties) when compared to the traditional petroleum-based plastics, the use of such biopolymers in large-scale is still limited. Several approaches of chitosan composites in the packaging industry are emerging to overcome some of the disadvantages of pristine polymers. Thus, this work intends to present the current trends and the future challenges towards production and application of chitosan composites in the food packaging industry.publishersversionpublishe
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