206 research outputs found

    The chromosomal passenger complex and the spindle assembly checkpoint: kinetochore-microtubule error correction and beyond

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    During mitosis, correct bipolar chromosome attachment to the mitotic spindle is an essential prerequisite for the equal segregation of chromosomes. The spindle assembly checkpoint can prevent chromosome segregation as long as not all chromosome pairs have obtained bipolar attachment to the spindle. The chromosomal passenger complex plays a crucial role during chromosome alignment by correcting faulty chromosome-spindle interactions (e.g. attachments that do not generate tension). In the process of doing so, the chromosomal passenger complex generates unattached chromosomes, a specific situation that is known to promote checkpoint activity. However, several studies have implicated an additional, more direct role for the chromosomal passenger complex in enforcing the mitotic arrest imposed by the spindle assembly checkpoint. In this review, we discuss the different roles played by the chromosomal passenger complex in ensuring proper mitotic checkpoint function. Additionally, we discuss the possibility that besides monitoring the presence of unattached kinetochores, the spindle assembly checkpoint may also be capable of responding to chromosome-microtubule interactions that do not generate tension and we propose experimental set-ups to study this

    ProFlex: A Probabilistic and Flexible Data Storage Protocol for Heterogeneous Wireless Sensor Networks

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    This paper presents ProFlex, a proactive data distribution protocol for heterogeneous wireless sensor networks (HWSNs). ProFlex guarantees robustness in data retrieval by intelligently managing data replication among selected storage nodes in the network. Contrarily to related protocols in the literature, ProFlex considers the resource constraints of sensor nodes and constructs multiple data replication structures, which are managed by more powerful nodes. Additionally, ProFlex takes profit of the higher communication range of such powerful nodes in the network and use the long link to improve data distribution. When compared with Supple -- a related protocol, we show by simulation that Proflex increases the network resilience under failures circumstances, decreases the overhead of transmitted messages, and decreases the number of hops to find a specific data in the network.Cet article porte sur la proposition d'un protocole de données proactif de distribution pour les réseaux de capteurs sans fil hétérogènes (HWSNs). Notre protocole, ProFlex, garantit la robustesse de la récupération des données grâce à sa gestion intelligente de la réplication des données entre les nœuds de stockage sélectionnés dans le réseau. Contrairement à d'autres protocoles dans la littérature, ProFlex considère les contraintes de ressources de capteurs et construit plusieurs structures de réplication des données, qui sont gérés par des nœuds plus puissants. En outre, ProFlex profite de la meilleure communication radio de ces nœuds plus puissants et utilise ces longues portée pour améliorer la distribution des données. Nous avons comparé ProFlex avec le protocole Supple et nous avons montré par simulation que Proflex augmente la résilience du réseau, même dans des circonstances des pertes de messages, diminue la surcharge de messages transmis, et diminue le nombre de sauts nécessaire pour trouver un ensemble de données spécifiques dans le réseau

    Cross-cultural adaptation and measurement properties of the Portuguese version of the Ankle Instability Instrument

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    Chronic ankle instability is one of the most common clinical conditions in the general population, especially in adult athletes. The cross-cultural adaptation of self-reported questionnaires that identify and classify this condition contribute to criteria standardization in research but also in rehabilitation. Aim of Study. To validate the Ankle Instability Instrument to the Portuguese population and to investigate its psychometric properties. Material and Methods. Linguistic and semantic equivalence of the original version of the Ankle Instability Instrument to the Portuguese population was firstly performed. The Portuguese version of the Ankle Instability Instrument was then applied to 81 higher education adult students, with (n = 59) and without history of ankle sprain (n = 22). Participants were evaluated two times with an interval of one week to assess the psychometric properties of the Portuguese version of the Ankle Instability Instrument. Results. In the reliability of binary responses based on the test retest, the tetrachoric correlation coefficient ranged from 0.99 to 1.00. In addition, the Kuder–Richardson coefficient was 0.79 suggesting good internal consistency. Conclusions. Test-retest showed an almost perfect match in all answers between the two moments, which seem to be related to sample characteristics. The internal consistency value was similar to the one obtained in the original version. The Portuguese version of the Ankle Instability Instrument is highly reliable and can be used in clinical practice.info:eu-repo/semantics/publishedVersio

    Survey on solar X-ray flares and associated coherent radio emissions

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    The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% they are the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them with extended duration. Despite the spatial association (same active region), the noise storm variations are found to be only loosely correlated in time with the X-ray flux. In a surprising 17% of the HXR flares, no coherent radio emission was found in the extremely broad band surveyed. The association but loose correlation between HXR and coherent radio emission is interpreted by multiple reconnection sites connected by common field lines.Comment: Solar Physics, in pres

    Cardiovascular abnormalities in patients with oral cleft: a clinical-electrocardiographic-echocardiographic study

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    OBJECTIVES: The present study aims to describe the clinical, electrocardiographic, and echocardiographic cardiological findings in a group of patients with oral clefts. METHODS: This is a prospective cross-sectional study on 70 children (age range from 13 days to 19 years) with oral clefts who attended the multidisciplinary program of a university hospital from March 2013 to September 2014. The patients were evaluated by a pediatric cardiologist and underwent detailed anamnesis, physical examination, electrocardiogram, and echocardiogram. RESULTS: Sixty percent of the patients were male; 55.7% presented with cleft lip and palate, and 40.0% presented with health complaints. Comorbidities were found in 44.3%. Relevant pregnancy, neonatal, family and personal antecedents were present in 55.7%, 27.1%, 67.2%, and 24.3% of the patients, respectively. Regarding the antecedents, 15.2% of the patients presented with a cardiac murmur, 49.0% with a familial risk of developing plurimetabolic syndrome, and 6% with family antecedents of rheumatic fever. Electrocardiographic evaluation showed one case of atrioventricular block. Echocardiograms were abnormal in 35.7% of the exams, including 5 cases of mitral valve prolapse — one of which was diagnosed with rheumatic heart disease. CONCLUSION: The finding of a family risk of developing plurimetabolic syndrome and a diagnosis of rheumatic heart disease indicates that patients with oral clefts may be more prone to developing acquired heart disease. Thus, our findings highlight the importance of anamnesis and methodological triangulation (clinical-electrocardiographic-echocardiographic) in the investigation of patients with oral clefts and emphasize that cardiological follow-up to evaluate acquired and/or rhythm heart diseases is necessary. This strategy permits comorbidity prevention and individualized planned treatment

    Alpha-thalassemia due to novel deletions and complex rearrangements in the subtelomeric region of chromosome 16p

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    2º Dia do Jovem Investigador do Instituto Nacional de Saúde Doutor Ricardo Jorge, INSA, 8 maio 2017Introduction: Inherited deletions removing the α-globin genes and/or their upstream regulatory elements (MCSs) give rise to alpha-thalassemia, one of the most common genetic recessive disorders worldwide. The pathology is characterized by microcytic hypochromic anemia due to reduction of the α-globin chain synthesis, which are essential for hemoglobin tetramerization. Material and Methods: In order to clarify the suggestive α-thalassemia phenotype in eleven patients, we performed Multiplex Ligation-dependent Probe Amplification with commercial and synthetic engineered probes, gap-PCR, and Sanger sequencing to search for deletions in the subtelomeric region of chromosome 16p. Results: We have identified five distinct large deletions, two of them novel, and one indel. The deletions range from approximately 3.3 to 323 kb, and i) remove the whole α-globin cluster; or ii) remove exclusively the upstream regulatory elements leaving the α-globin genes structurally intact. The indel consists in the loss of MCS-R2 (HS-40), which is the most important distal regulatory element for the α-globin gene expression, and the insertion of 39 bp, seemingly resulting from a complex rearrangement involving two DNA segments (probably from chromosome 3q) bridging the deletion breakpoints with a CC-bp orphan sequence in between. Finally, in one patient no α-globin deletion or point mutation were found. This patient revealed to be a very unusual case of acquired alpha-thalassemia associated with a myelodysplastic syndrome. Conclusions: Our study widens the spectrum of molecular lesions by which α-thalassemia may occur and emphasizes the importance of diagnosing large α-zero-deletions to provide patients with appropriate genetic counseling.info:eu-repo/semantics/publishedVersio

    Reed-sternberg cells form by abscission failure in the presence of functional aurora B kinase

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    Large multinucleated Reed-Sternberg cells (RS) and large mononucleated Hodgkin cells (H) are traditionally considered to be the neoplastic population in classical Hodgkin lymphoma, (cHL) and postulated to promote the disease. However, the contribution of these larger cells to the progression of cHL remains debatable. We used established cHL cell lines and cHL cellular fractions composed of small mononucleated cells only or enriched in large RS/H cells to investigate RS/H cell origin and to characterize the cells which they derive from. We confirm that the small mononucleated cells give rise to RS/H cells, and we show that the latter proliferate significantly more slowly than the small cells. By using live-cell imaging, we demonstrate that binucleated RS cells are generated by failure of abscission when a few small cells attempt to divide. Finally, our results reveal that the small mononucleated cells are chromosomally unstable, but this is unlikely to be related to a malfunctioning chromosomal passenger protein complex. We propose that the small mononucleated cells, rather than the RS/H cells, are the main drivers of cHL

    Dental Informatics: an emerging discipline

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    Este trabalho de revisão de literatura pretende demonstrar não só a importância da introdução da disciplina de Informática Odontológica no currículo das Faculdades de Odontologia mas também no cotidiano do médico-dentista ou cirurgião-dentista. Nos últimos anos houve um rápido desenvolvimento da Informática aplicada à Odontologia, sobretudo em áreas dedicadas ao exame do paciente, ao diagnóstico e ao plano de tratamento. Os sistemas CAD-CAM, as sondas periodontais computadorizadas, os aparelhos de radiologia digital, as câmaras intra-orais são exemplos da aplicação da Informática em Odontologia. É neste sentido que surge a disciplina de Informática Odontológica, uma área em constante desenvolvimento, que tem por base a aplicação de computadores e ciências de informação para melhorar a prática clínica, a pesquisa, a educação e a gestão. É importante que simultaneamente com a formação em Odontologia haja também adequada formação em Informática Odontológica. Atualmente os avanços tecnológicos e as pesquisas científicas requerem interdisciplinaridade e integração de uma grande quantidade de informação, muitas vezes proveniente de fontes díspares, havendo necessidade de compilar a informação em bases de dados. Os meios informáticos podem aumentar significativamente a velocidade de integração e correlação dessa informação, tornando o diagnóstico médico-odontológico mais rápido e a implementação da terapêutica mais eficaz. Palavras-chave: Informática Odontológica; bioinformática; base de dados; formação odontológica; diagnósticoThis literature review aimed to present the importance of the discipline of Dental Informatics for the curriculum of dental schools and daily dental practice. In the last years there was a fast development of Informatics applied to Dentistry, especially in areas related to patient exam, diagnosis, and treatment plan. CAD-CAM systems, computerized periodontal probes, digital radiography, and intraoral cameras are examples of the application of Informatics in Dentistry. Dental Informatics is a discipline showing constant development and is based on the application of computers and information science to improve clinical practice, research, education, and management. Therefore, it is important that Dental Informatics is included in the dental curriculum. At present the technological advances and scientific research require interdisciplinary approach and integration of large amount of information. This information usually comes from several sources, which requires its compilation in databases. Informatics media can significantly increase the velocity of integration and correlation of necessary information to speed up the medical-dental diagnosis and improve treatment efficacy. Key words: Dental informatics; bioinformatics, databases; dental education; diagnosisinfo:eu-repo/semantics/publishedVersio

    Molecular detection of tick-borne bacteria and protozoa in cervids and wild boars from Portugal

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    Background: Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal.Methods: One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR.Results: Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp.Conclusions: This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken
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