778 resultados para Maths lessons execution


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The amount of sequence data available today highly facilitates the access to genes from many gene families. Primers amplifying the desired genes over a range of species are readily obtained by aligning conserved gene regions, and laborious gene isolation procedures can often be replaced by quicker PCR-based approaches. However, in the case of multigene families, PCR-based approaches bear the often ignored risk of incomplete isolation of family members. This problem is most prominent in gene families with highly variable and thus unpredictable number of gene copies among species, such as in the major histocompatibility complex (MHC). In this study, we (i) report new primers for the isolation of the MHC class IIB (MHCIIB) gene family in birds and (ii) share our experience with isolating MHCIIB genes from an unprecedented number of avian species from all over the avian phylogeny. We report important and usually underappreciated problems encountered during PCR-based multigene family isolation and provide a collection of measures to help significantly improving the chance of successfully isolating complete multigene families using PCR-based approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

DNA must constantly be repaired to maintain genome stability. Although it is clear that DNA repair reactions depend on cell type and developmental stage, we know surprisingly little about the mechanisms that underlie this tissue specificity. This is due, in part, to the lack of adequate study systems. This review discusses recent progress toward understanding the mechanism leading to varying rates of instability at expanded trinucleotide repeats (TNRs) in different tissues. Although they are not DNA lesions, TNRs are hotspots for genome instability because normal DNA repair activities cause changes in repeat length. The rates of expansions and contractions are readily detectable and depend on cell identity, making TNR instability a particularly convenient model system. A better understanding of this type of genome instability will provide a foundation for studying tissue-specific DNA repair more generally, which has implications in cancer and other diseases caused by mutations in the caretakers of the genome.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Field censuses and laboratory experiments show that in the Argentine ant, Iridomyrmex humilis (Mayr), c. 90% of the queens are executed by workers in May, at the beginning of the reproductive season. The reduction in the number of queens probably decreases the inhibition exerted by queens on the differentiation of sexuals and thus allows the production of new queens and males shortly thereafter. In the laboratory, there was no correlation between the percentage of queens executed and their weight or fecundity. At the time of execution of queens, nearly all queens were of the same age; less than 1 year. Therefore it is not likely that the age of queens plays any role in the choice that workers make in the queens they executed. Execution of these queens results in a heavy energetic cost for the colony which amounts c. 8% of the total biomass. This behaviour of workers executing nestmate queens is discussed with regard to possible evolutionary significance at the queen and worker level.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

“Magic for a Pixeloscope” is a one hour show conceived to berepresented in a theater scenario that merges mixed and augmented reality (MR/AR) and full-body interaction with classical magic to create new tricks. The show was conceived by an interdisciplinary team composed by a magician, twointeraction designers, a theater director and a stage designer. Themagician uses custom based hardware and software to createnew illusions which are a starting point to explore new languagefor magical expression. In this paper we introduce a conceptualframework used to inform the design of different tricks; weexplore the design and production of some tricks included in theshow and we describe the feedback received on the world premiere and some of the conclusions obtained.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study analyses the determinants of the rate of temporary employment in various OECD countries using both macro-level data drawn from the OECD and EUROSTAT databases, as well as micro-level data drawn from the 8th wave of the European Household Panel. Comparative analysis is set out to test different explanations originally formulated for the Spanish case. The evidence suggests that the overall distribution of temporary employment in advanced economies does not seem to be explicable by the characteristics of national productive structures. This evidence seems at odds with previous interpretations based on segmentation theories. As an alternative explanation, two types of supply-side factors are tested: crowding-out effects and educational gaps in the workforce. The former seems non significant, whilst the effects of the latter disappear after controlling for the levels of institutional protection in standard employment during the 1980s. Multivariate analysis shows that only this latter institutional variable, together with the degree of coordinated centralisation of the collective bargaining system, seem to have a significant impact on the distribution of temporary employment in the countries examined. On the basis of this observation, an explanation of the very high levels of temporary employment observed in Spain is proposed. This explanation is consistent with both country-specific and comparative evidence.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pharmacological treatment of hypertension represents a cost-effective way of preventing cardiovascular and renal complications. To benefit maximally from antihypertensive treatment, blood pressure should be brought to below 140/90 mmHg in every hypertensive patient, and even lower (< 130/80 mmHg) if diabetes or renal disease co-exists. Such targets cannot usually be reached using monotherapies. This is especially true in patients who present with a high cardiovascular risk. The co-administration of two agents acting by different mechanisms considerably increases the blood pressure control rate. Such combinations are not only efficacious, but are also well tolerated, and some fixed low-dose combinations even have a placebo-like tolerability. This is the case for the preparation containing the angiotensin-converting enzyme inhibitor perindopril (2 mg) and the diuretic indapamide (0.625 mg), a fixed low-dose combination that has been shown in controlled trials to be more effective than monotherapies in reducing albuminuria, regressing cardiac hypertrophy and improving the stiffness of large arteries. Using this combination to initiate antihypertensive therapy has been shown in a double-blind trial (Strategies of Treatment in Hypertension: Evaluation; STRATHE) to normalize blood pressure (< 140/90 mmHg) in significantly more patients (62%) than a sequential monotherapy approach based on atenolol, losartan and amlodipine (49%) and a stepped-care strategy based on valsartan and hydrochlorothiazide (47%), with no difference between the three arm groups in terms of tolerability. An ongoing randomized trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; ADVANCE) is a study with a 2 x 2 factorial design assessing the effects of the fixed-dose perindopril-indapamide combination and of the intensive gliclazide modified release-based glucose control regimen in type 2 diabetic patients, with or without hypertension. A total of 11 140 patients were randomly selected. Within the first 6 weeks of treatment (run-in phase), the perindopril-indapamide combination lowered blood pressure from 145/81 +/- 22/11 mmHg (mean +/- SD) to 137/78 +/- 20/10 mmHg. Fixed-dose combinations are becoming more and more popular for the management of hypertension, and are even proposed by hypertension guidelines as a first-line option to treat hypertensive patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Atrial fibrillation (AF) is the most common arrhythmia and among the leading causes of stroke and heart failure in Western populations. Despite the increasing size of clinical trials assessing the efficacy and safety of AF therapies, achieved outcomes have not always matched expectations. Considering that AF is a symptom of many possible underlying diseases, clinical research for this arrhythmia should take into account their respective pathophysiology. Accordingly, the definition of the study populations to be included should rely on the established as well as on the new classifications of AF and take advantage from a differentiated look at the AF-electrocardiogram and from increasingly large spectrum of biomarkers. Such an integrated approach could bring researchers and treating physicians one step closer to the ultimate vision of personalized therapy, which, in this case, means an AF therapy based on refined diagnostic elements in accordance with scientific evidence gathered from clinical trials. By applying clear-cut patient inclusion criteria, future studies will be of smaller size and thus of lower cost. In addition, the findings from such studies will be of greater predictive value at the individual patient level, allowing for pinpointed therapeutic decisions in daily practice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper identifies selected issues and lessons learned from the implementation of a national program of prevention and control of non-communicable diseases (NCD) during the past 20 years in the Seychelles, a small island state in the African region. As early as in 1989, population-based surveys demonstrated high levels of several cardiovascular risk factors, which prompted an organized response by the government. The early creation of a NCD unit within the Ministry of Health, coupled with cooperation with international partners, enabled incremental capacity building and coherent development of NCD programs and policy. Information campaigns and screening for hypertension and diabetes in work/public places raised awareness and rallied increasingly broad awareness and support to NCD prevention and control. A variety of interventions were organized for tobacco control and comprehensive tobacco control legislation was enacted in 2009 (including total bans on tobacco advertising and on smoking in all enclosed public and work places). A recent School Nutrition Policy prohibits the sale of soft drinks in schools. At primary health care level, guidelines were developed for the management of hypertension and diabetes (these conditions are managed in all health centers within a national health system); regular interactive education sessions were organized for groups of high risk patients ("heart health club"); and specialized "NCD nurses" were trained. Decreasing prevalence of smoking is evidence of success, but the raising "diabesity epidemic" calls for strengthened health care to high-risk patients and broader multisectoral policy to mould an environment conducive to healthy behaviors. Key components of NCD prevention and control in Seychelles include effective surveillance mechanisms supplemented by focused research; generating broad interest and consensus on the need for prevention and control of NCD; mobilizing leadership and commitment at all levels; involving local and international expertise; building on existing efforts; and seeking integrated, multi-disciplinary and multisectoral approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

RÉSUMÉ : Le sexe des individus peut être déterminé par l'environnement ou la génétique. Lorsque la détermination du sexe est génétique, il y a dans le génome, la présence de chromosomes spécifiques qui détermineront le sexe. Dans cette thèse, j'ai étudié l'évolution des chromosomes sexuels et dans quel contexte des marqueurs sur ces chromosomes peuvent être utilisés. Pour explorer la formation du chromosome Y, nous avons étudié les caractéristiques des chromosomes sexuels chez la rainette verte, Hyla arborea. Dans un premier temps, nous avons utilisé un marqueur situé sur les chromosomes sexuels X et Y chez plusieurs espèces appartenant au groupe de la rainette verte. Cela nous a permis de révéler chez toutes ces espèces une hétérogamétie mâle. Dans un deuxième temps, nous avons tiré profit de deux autres marqueurs situés sur les chromosomes sexuels pour montrer que la recombinaison est supprimée chez les mâles mais pas chez les femelles. Pour expliquer la réduction de la variabilité sur le chromosome Y, il n'est pas nécessaire d'invoquer le balayage sélectif ou la sélection d'arrière-plan : le nombre de copies plus petit du chromosome Y dans le génome et l'absence de recombinaison suffisent à l'expliquer. Nous avons également analysé plus en détail la suppression de la recombinaison chez les mâles de H. arborea. Les modèles classiques de l'évolution des chromosomes sexuels supposent que la taille de la région non-recombinante augmente progressivement pendant l'évolution du chromosome Y, due à l'accumulation de changements structuraux. Dans cette étude, nous montrons un modèle différent, à savoir que la recombinaison est supprimée ou diminuée non seulement sur les chromosomes sexuels mais aussi sur les autosomes chez les mâles, dû à l'action de modificateurs généraux. En utilisant des marqueurs localisés sur le chromosome Y, ainsi que sur l'ADN mitochondrial et le chromosome X, nous avons étudié l'histoire évolutive de la musaraigne musette, Crocidura russula. Cette étude illustre que les analyses génétiques avec plusieurs types de marqueurs génétiques peuvent faciliter l'interprétation de l'histoire évolutive des espèces, mais que l'utilisation des marqueurs sur les chromosomes X et Y pour des études phylogéographiques est limitée par le peu de polymorphisme observé sur ces deux types de marqueurs. Le même jeu de données combiné avec des simulations a été employé pour comprendre les facteurs responsables de la faible variabilité sur le chromosome Y qui peut être expliqué, dans notre étude, par la démographie et les traits d'histoire de vie de C. russula. SUMMARY The sex of an individual is determined either by its environment or its genetics. Genetic sex determination relies on the presence of specific chromosomes that will determine the sex of their bearer. In this thesis, I studied the evolution of the sex chromosomes and the context in which markers on this type of chromosomes can be used. To explore the evolution of a Y chromosome, we studied the nascent sex chromosomes in the European tree frog Hyla arborea. First; we amplified a sex specific marker in several related species of European tree frog and found a homogeneous pattern of male heterogamety. Secondly, we used two additional sex-specific markers to show that recombination is suppressed in males but not in females. There is, therefore, no need to invoke background selection or selective sweeps to explain the reduced genetic variability on the Y chromosome, because the lower number of copies of the Y chromosomes per breeding pair and the absence of recombination are sufficient. To further analyze the suppression of recombination in male European. tree frogs, we constructed a microsatellite linkage map for this species. Classical models of sex-chromosome evolution assume that the non-recombining region expands progressively during the long-term evolution of the Y chromosome, owing to the accumulation of structural changes. Here we show a strikingly different pattern: recombination is suppressed or depressed both on sex chromosomes and autosomes in the heterogametic sex, presumably due to the action of general modifiers. We investigated the evolutionary history of the greater white-toothed shrew, Crocidura russula, using markers on both sex chromosomes and mtDNA. This study illustrates that multilocus genetic analyses facilitates the interpretation of a species' evolutionary history. It also demonstrates that phylogeographic inferences from X and Y chromosomal markers are restricted by the low levels of observed polymorphism. Combining this genetic study with simulations, we determined that the demography and the life-history traits of this species can alone be responsible for the low Y diversity. In conclusion, this thesis shows that sex chromosomes, in combination with autosomes or mtDNA, are necessary to understand the evolution of sex chromosomes and to precisely infer the population history of a species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

AbstractOBJECTIVETo report the nurse's experience of inclusion in interdisciplinary clinical study about technological innovation, involving people with spinal cord injury.METHODDescriptive experience report. The empirical support was based on notes about perspectives and practice of clinical research, with a multi-professional nursing, physical education, physiotherapy and engineering staff.RESULTThe qualification includes the elaboration of the document for the Ethics Committee, familiarization among the members of staff and with the studied topic, and also an immersion into English. The nurse's knowledge gave support to the uptake of participants and time adequacy for data collection, preparation and assistance of the participants during the intervention and after collection. Nursing theories and processes have contributed to reveal risky diagnoses and the plan of care. It was the nurse's role to monitor the risk of overlapping methodological strictness to the human aspect. The skills for the clinical research must be the object of learning, including students in multidisciplinary researches.CONCLUSIONTo qualify the nurse for clinical research and to potentialize its caregiver essence, some changes are needed in the educational system, professional behavior, attitude and educational assistance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Free-living amoebae serve as hosts for a variety of amoebae-resisting microorganisms, including giant viruses and certain bacteria. The latter include symbiotic bacteria as well as bacteria exhibiting a pathogenic phenotype towards amoebae. Amoebae-resisting bacteria have been shown to be widespread in water and to use the amoebae as a reservoir, a replication niche, a protective armour as well as a training ground to select virulence traits allowing survival in the face of microbicidal effects of macrophages, the first line of defense against invading pathogens. More importantly, amoebae play a significant role as a melting pot for genetic exchanges. These ecological and evolutionary roles of amoebae might also be at play for giant viruses and knowledge derived from the study of amoebae-resisting bacteria is useful for the study and understanding of interactions between amoebae and giant viruses. This is especially important since some genes have spread in all domains of life and the exponential availability of eukaryotic genomes and metagenomic sequences will allow researchers to explore these genetic exchanges in a more comprehensive way, thus completely changing our perception of the evolutionary history of organisms. Thus, a large part of this review is dedicated to report current known gene exchanges between the different amoebae-resisting organisms and between amoebae and the internalized bacteria.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Interpretación versus Ejecución es un proyecto que pretende sentar las bases para el planteamiento de una versión propia e informada de obras de diferentes estilos musicales. Se presta especial atención a las prácticas propias de cada estilo – barroco, clásico, romántico y contemporáneo - y su posible aplicación con la flauta moderna en cuatro obras concretas. La metodología empleada ha consistido en la búsqueda de información en tratados, libros, artículos, así como entrevistas y clases con músicos expertos en cada uno de los temas. El proyecto pretende impulsar el interés del joven músico por una búsqueda personal e informada de las prácticas interpretativas que redunde en una interpretación propia de las obras que desee tocar.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Now more than ever Capeverdean teachers are faced with student acts of violence which reverberate to the outer limits of our society at large. These situations have caused teachers to reflect upon their roles as educator and “promoter” of discipline. Some are even questioning their effectiveness in this process as they are challenged to discover if they are in the right place. How do teachers manage discipline? In the past, punishment was the rule of thumb and to some extent remains the measure of choice. But is this the most effective form of behavior management? What is the relationship between punishment and corrective behavior? This paper will discuss the affect that punishment has on the learning process as it attempts to suggest strategies in managing discipline with the objective of creating an effective learning environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents an analysis of the credibility of the EMScurrencies that covers the period before and after the increase in thebands of fluctuation. Our credibility indicator is based on the inferredprobabilities derived from the estimation of a Markov-switching model(Hamilton (1989)) applied to the expected rate of depreciation. Theresults show that, for most of the currencies, credibility has improved,at least transitorily, after the increase in the bands. However, for allcurrencies, the credibility measured by the indicator proposed in thispaper has been eroded recently even with the widened bands.