Teacher training processes and teachers' competence : A sociological study in the primary school

The paper describes part of a study whose aim was to investigate the relation between modalities of teacher training and modalities of pedagogic practice implemented in the science classroom. The study is focused on primary school context and analyses the evolution of teachers performance in terms of their acquisition of recognition and realisation rules, i.e. coding orientation, to specific scientific learning contexts. Theoretically, the study is based on Bernstein’s theory of pedagogic discourse (1999, 2000)which provided the concepts to characterise the modalities of teacher training and of classroom pedagogic practices and to analyse teachers’ evolution in terms of recognition and realisation rules. The sample was made up of four teachers and their four socially heterogeneous school classes. An action-research methodology was followed.The results suggest that the teacher training implemented was favourable to the teachers’ professional development and their competence to lead all children to a high level of scientific development. The efficiency of the training process has to be mostly attributed to the strong classification of the researcher-teachers relation and to the strong framing of evaluation criteria, selection and sequence, together with weak framing of hierarchical rules and pacing.Fundação Calouste Gulbenkian, Instituto de Inovação Educacional e Fundação para a Ciência e Tecnologia (FCT)

L-asparaginase recovery through supported ionic liquid materials based on silica

Acute lymphoblastic leukemia (ALL) accounts with approximately 6500 new cases in the United States each year [1]. The first-line biopharmaceutical being used to treat ALL, Oncaspar, is based on L-asparaginase (LA), with annual sales of approximately USD $100 million [2]. The main problem related to the therapeutic use of LA is the difficulty in its purification, accounting for up to 80% of total production costs [3]. Therefore, it is crucial to find new strategies to purify LA in order to decrease its current cost and allow its routinely use by a widespread population. Supported ionic liquid materials based on silica (SILs) are reported in the literature for the separation of natural compounds from vegetable biomass [4]. Although SILs represent a class of materials with high potential in protein purification, this specific application has been scarcely considered [5]. In this work, the search for SILs able to establish (non-covalent) specific interactions with LA, which subsequently allow its purification from the fermentation broth in which it is produced, was studied. In a first set of experiments, commercial LA was used in order to understand the adsorption behaviour of the enzyme onto SILs. Experimental conditions, such as pH, contact time and SILs/LA ratio were evaluated and optimized in what concerns the LA recovery yield. LA activity was assessed by the Nessler reaction, which quantifies the amount of ammonium released after the enzymatic reaction [6]. The results show that the ideal conditions for LA are pH 8 and a contact time with SILs of 30 min. With the envisioned strategy, process costs, energy consumed, and waste generated, can be considerably reduced, which can lead to the LA cost decrease and wider application. Further investigations on the purification of LA from the fermentation broth are ongoing.publishe

Synthesis of sugars embodying conjugated carbonyl systems and related triazole derivatives from carboxymethyl glycoside lactones. Evaluation of their antimicrobial activity and toxicity.

International audienceThe synthesis of a series of pyranoid derivatives comprising a conjugated carbonyl function and related triazole derivatives, structurally suitable for bioactivity evaluation, was achieved in few steps starting from readily available carboxymethyl glycoside lactones (CMGL). 3-Enopyranosid-2-uloses were generated by oxidation/elimination of tri-O-acylated 2-hydroxy pyranosides. Subsequent Wittig olefination provided stereoselectively 2-C-branched-chain conjugated dienepyranosides with (E)-configuration around the exocyclic double bond. A heterogeneous CuI/Amberlyst-catalyzed 'click' chemistry protocol was used to convert glycosides bearing a propargyl moiety into the corresponding 1,2,3-triazoles. These new molecules were screened for their in vitro antibacterial and antifungal activities and those containing conjugated carbonyl systems demonstrated the best efficacy. (N-Dodecylcarbamoyl)methyl enone glycerosides were the most active ones among the enones tested. The α-anomer displayed very strong activities against Bacillus cereus and Bacillus subtilis and strong activity toward Enterococcus faecalis and the fungal pathogen Penicillium aurantiogriseum. The corresponding β-anomer presented a very strong inhibitory effect against two fungal species (Aspergillus niger and P. aurantiogriseum). (N-Dodecyl-/N-propargyl/or N-benzylcarbamoyl)methyl dienepyranosides exhibited selectively a strong activity toward E. faecalis. Further acute toxicity evaluation indicated low toxic effect of the (N-dodecylcarbamoyl)methyl enone glyceroside α-anomer and of the carbamoylmethyl dienepyranosides N-protected with propargyl or benzyl groups

Detecting antibody-labeled BCG MNPs using a magnetoresistive biosensor and magnetic labeling technique

Tuberculosis is still a major global health concern, causing the estimated death of 1.5 million people per year and being associated with high morbidity. The development of point-of-care diagnostic tools for tuberculosis is mandatory, especially because the fast and accurate detection of the slow-growing Mycobacterium tuberculosis by the conventional diagnostic tests is difficult. The objective of this work was to develop the first steps to achieve a portable method for the diagnosis of tuberculosis, by a sandwich-immunoassay combined with magnetoresistive biochip technology. With the purpose of conjugating 250 nm streptavidin-coated magnetic nanoparticles with anti-M. tuberculosis biotinylated antibodies, Mycobacterium bovis Bacillus Calmette-Guerin was used as a surrogate for M. tuberculosis bacteria. After magnetic capture, target bacteria were brought in contact with the surface of the magnetoresistive biochip previously functionalized with a secondary anti-M. tuberculosis antibody. Magnetically labeled cells were detected by an array of spin-valve sensors, which change their electrical resistance in the presence of the fringe field of the magnetic particles. Optimization studies on the efficiency of the magnetic capture and further recognition of the bacteria by the secondary antibody on the biochip surface were conducted. The results on the magnetoresistive biochip showed a clear difference in the signal between specific and control ( nonspecific) sensors, suggesting the usefulness of this technique as a potential biorecognition tool for the development of a point-of-care diagnostic method for tuberculosis.Acknowledgments: Teresa Barroso thanks FCT for her PhD Grant SFRH/BD/33904/2009.info:eu-repo/semantics/publishedVersio

Tuberculosis among the homeless: should we change the strategy?

BACKGROUND: Tuberculosis (TB) is a major concern among high-risk populations such as the homeless. OBJECTIVES: To evaluate TB incidence and treatment outcomes among homeless patients in Portugal and to identify predictors of unsuccessful TB treatment outcomes among the homeless. DESIGN: This was a retrospective cohort study of all TB patients notified in Portugal from 2008 to 2014. Characteristics of homeless TB patients were assessed and predictors of unsuccessful TB treatment were determined using logistic regression. RESULTS: TB incidence among the homeless was 122/100 000 homeless persons and was positively correlated with TB incidence among non-homeless persons. Homeless TB patients had a higher prevalence of alcohol and/or drug use, human immunodeficiency virus (HIV) co-infection, cavitary TB and smear positivity. The rate of unsuccessful treatment outcomes among the homeless was 28.6%, and was significantly associated with increased age, injection drug use (IDU) and HIV co-infection. CONCLUSION: TB incidence among homeless persons was five times that among the non-homeless, and higher in regions with greater TB incidence among non homeless persons. The successful treatment outcome rate was lower. Predictors of unsuccessful treatment were age, IDU and HIV co-infection. Integrated TB programmes targeting homeless and non-homeless patients, with measures targeting specific characteristics, may contribute to TB elimination in Portugal.CONTEXTE : La tuberculose (TB) est un souci majeur dans les populations à haut risque comme les personnes sans domicile fixe. OBJECTIFS : Evaluer le taux d’incidence de la TB et les resultats du traitement parmi des patients sans domicile fixe au Portugal et identifier les facteurs de préediction d’ échec du traitement de la TB parmi ces patients. SCHÉMA : Etude rétrospective de cohorte incluant tous les patients TB notifies au Portugal entre 2008 et 2014. Les caractéristiques des patients sans domicile fixe ont été ́évaluées et les facteurs de prédiction d’ échec du traitement de la TB ont été déterminés par ŕegression logistique. RESULTATS : Le taux d’incidence de la TB parmi les personnes sans domicile fixe a été de 122/100 000, et il a été positivement corrélé avec l’incidence de la TB parmi le reste de la population. Les patients tuberculeux sans domicile fixe avaient une prévalence plus élevée de consommation d’alcool et/ou de drogues, de co- infection au virus de l’immunodéficience humaine (VIH), de forme caverneuse et de frottis positif. Le taux d’ ́echec du traitement a ́et ́e de 28,6% ; l’ ́echec a ́ et ́esignificativement associé à un âge plus avancé, à la consommation de drogues injectables et à la co-infection par le VIH. CONCLUSION : L’incidence dela TB parmi les personnes sans domicile fixe a été cinq fois plus élevée que celle du reste de la population et plus haute dans les régions ou l’incidence dans le reste de la population est egalement plus élevée. Leur taux d’ échec du traitement à été plus faible. Les facteurs de prédiction d’ échec du traitement ont été l´âge, la consommation de drogues injectables et la co-infection `a VIH. Des programmes de TB intégrés ciblant les patients sans domicile fixe et les autres, avec des mesures spécifiques adaptées à leurs caractéristiques particulières, pourrait contribuer à l’ élimination de la TB au Portugal.MARCO DE REFERENCIA: La tuberculosis (TB) constituye una gran preocupación en las poblaciones muy vulnerables como las personas sin hogar. OBJETIVOS: Evaluar la tasa de incidencia de TB y los desenlaces terapéuticos en las personas sin domicilio en Portugal y definir los factores pronósticos de fracaso terapéutico en este grupo de la población. MÉTODO: Fue este un estudio retrospectivo de cohortes de todos los pacientes con diagnóstico de TB notificados del 2008 al 2014 en Portugal. Mediante un análisis de regresión logística se analizaron las características de los pacientes tuberculosos sin hogar y los factores pronósticos de fracaso terapéutico. RESULTADOS: La tasa de incidencia de TB en la población sin hogar fue 122 por 100 000 personas y exhibió una correlación positiva con la incidencia de TB en las personas con domicilio. Los pacientes con diagnóstico de TB y sin hogar presentaron una prevalencia más alta de consumo de alcohol y/o de drogas, de coinfección por el virus de la inmunodeficiencia humana (VIH), de lesiones cavernosas y de resultados positivos de la baciloscopia. La tasa de fracaso terapéutico en esta población fue 28,6% y se asoción de manera significativa con una mayor edad, el consumo de drogas intravenosas y la coinfección por el VIH. CONCLUSIÓN: La incidencia de TB en las personas sin hogar fue cinco veces mayor que en las personas con domicilio y fue más alta en las regiones con una mayor incidencia de TB en las personas con domicilio. La tasa de éxito terapéutico en las personas sin hogar fue más baja. Los factores pronósticos de fracaso terapéutico fueron la edad, el consumo de drogas intravenosas y la coinfecció non por el VIH. La ejecución de programas integrados de atención de la TB dirigidos a las personas sin hogar y con domicilio, que comporten medidas específicas que aborden sus características particulares, podrıa contribuir a la eliminación de la TB en PortugalStudy Group for Infectious Diseases of Instituto de Saúde Púublica da Universidade do Porto who collaborated on this project: B Miranda, C Carvalho, C Matos, C Carvalho, G Rodrigues, J Goncalves, L Maio and T Rito. This work was supported by contributions from Iceland, Liechtenstein and Norway through the European Economic Area Grants under the Public Health Initiatives Programme (PT 06, grant number 138DT1). RG was also partially supported by Centro de Matemática da Universidade do Porto (UID/MAT/00144/2013), which is funded by Fundação do Ministério de Ciência e Tecnologia(Portugal) with national (MEC) and European structural funds (Fonds europeen de d ́eveloppement economique et regional) under the PT2020 Partnership Agreementinfo:eu-repo/semantics/publishedVersio

Expression, purification and bioactivity of recombinant human bone morphogenetic protein-4,-9,-10,-11 and-14 produced in Escherichia coli for tissue engineering applications

[Excerpt] Bone morphogenetic proteins (BMPs) are cytokines from the TGFb superfamily, with important roles during embryonic development and in inducing bone and cartilage in the adult body. In this contribution, we report the expression of recombinant human BMP-4, BMP-9, BMP-10, BMP-11 (or growth differentiation factor-11, GDF-11) and BMP-14 (GDF-5), using Escherichia coli pET-25b expression system. The BMPs were purified by affinity chromatography and its bioactivity accessed in C2C12 cell line, by screening the expression of osteogenic markers with RT-PCR. [...]Fundação para a Ciência e Tecnologia for PhD grant SFRH/BD/17049/2004 and project ElastM POCI/CTM/ 57177/2004 supported by FEDER and the Fundação para a Ciência e Tecnologia; European STREP Project HIPPOCRATES (NMP3-CT-2003-505758). The work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283).info:eu-repo/semantics/publishedVersio

An insight on the role of photosensitizer nanocarriers for Photodynamic Therapy

Photodynamic therapy (PDT) is a modality of cancer treatment in which tumor cells are destroyed by reactive oxygen species (ROS) produced by photosensitizers following its activation with visible or near infrared light. The PDT success is dependent on different factors namely on the efficiency of the photosensitizer deliver and targeting ability. In this review a special attention will be given to the role of some drug delivery systems to improve the efficiency of tetrapyrrolic photosensitizers to this type of treatment.publishe

Silk nanoparticles for delivery of human BMP-2 in bone regenerative medicine applications

[Excerpt] A tissue engineering approach combines the use of scaffold biomaterials, stem cells and growth factors. Bone morphogenetic proteins (BMPs) are growth factors that have sparked a great interest in tissue engineering due to their strong ability to promote new bone formation. Herein, we report the use of silk derived nanoparticles as carriers for delivery of human BMP-2. Silks are attractive biomaterials for tissue engineering due to its biocompatibility, slow biodegradability and excellent mechanical properties. Recombinant human BMP-2 was expressed in Escherichia coli and purified by affinity chromatography, showing bioactivity in human adipose stem cells. BMP2-containing silk particles were then prepared by a water-in-oil emulsion method. [...]info:eu-repo/semantics/publishedVersio

Motor uncoordination and neuropathology in a transgenic mouse model of Machado-Joseph disease lacking intranuclear inclusions and ataxin-3 cleavage products

Machado-Joseph disease (MJD) is a late-onset neurodegenerative disorder caused by a polyglutamine (polyQ) expansion in the ataxin-3 protein. We generated two transgenic mouse lineages expressing the expanded human ataxin-3 under the control of the CMV promoter: CMVMJD83 and CMVMJD94, carrying Q83 and Q94 stretches, respectively. Behavioral analysis revealed that the CMVMJD94 transgenic mice developed motor uncoordination, intergenerational instability of the CAG repeat and a tissue-specific increase in the somatic mosaicism of the repeat with aging. Histopathological analysis of MJD mice at early and late stages of the disease revealed neuronal atrophy and astrogliosis in several brain regions; however, we found no signs of microglial activation or neuroinflammatory response prior to the appearance of an overt phenotype. In our model, the appearance of MJD-like symptoms was also not associated with the presence of ataxin-3 cleavage products or intranuclear aggregates. We propose the transgenic CMVMJD94 mice as a useful model to study the early stages in the pathogenesis of MJD and to explore the molecular mechanisms involved in CAG repeat instability.We would like to thank to Dr. Henry Paulson for providing the anti-ataxin-3 serum, Dr. Monica Sousa for the pCMV vector and to Eng. Lucilia Goreti Pinto for technical assistance. AS-F., M.C.C., S.S. and C.B. received FCT fellowships (SFRH/BD/15910/2005; SFRH/BPD/28560/2006; PTDC/SAU-GMG/64076/2006; SFRH/BPD/20987/2004). This research was funded by Fundacao para a Ciencia e Tecnologia through projects FEDER/FCT, POCI/SAU-MMO/60412/2004, PTDC/SAU-GMG/64076/2006; and Ataxia MJD Research Project

Dominant negative effect of polyglutamine expansion perturbs normal function of ataxin-3 in neuronal cells

The physiological function of Ataxin-3 (ATXN3), a deubiquitylase (DUB) involved in Machado–Joseph Disease (MJD), remains elusive. In this study, we demonstrate that ATXN3 is required for neuronal differentiation and for normal cell morphology, cytoskeletal organization, proliferation and survival of SH-SY5Y and PC12 cells. This cellular phenotype is associated with increased proteasomal degradation of a5 integrin subunit (ITGA5) and reduced activation of integrin signalling and is rescued by ITGA5 overexpression. Interestingly, silencing of ATXN3, overexpression of mutant versions of ATXN3 lacking catalytic activity or bearing an expanded polyglutamine (polyQ) tract led to partially overlapping phenotypes. In vivo analysis showed that both Atxn3 knockout and MJD transgenic mice had decreased levels of ITGA5 in the brain. Furthermore, abnormal morphology and reduced branching were observed both in cultured neurons expressing shRNA for ATXN3 and in those obtained from MJD mice. Our results show that ATXN3 rescues ITGA5 from proteasomal degradation in neurons and that polyQ expansion causes a partial loss of this cellular function, resulting in reduced integrin signalling and neuronal cytoskeleton modifications, which may be contributing to neurodegeneration.National Institutes of Health (NIH) ‘(R01NS038712)Fundação para a Ciência e a Tecnologia (FCT) and COMPETE through the project ‘(PTDC/SAU-GMG/ 101572/2008)Fundação para a Ciência e a Tecnologia (FCT) - fellowships SFRH/BD/51059/2010, SFRH/BD/ 78388/2011 and SFRH/BPD/91562/201