O Diálogo Entre Teoria e Prática: uma Formação Continuada de Professores de Ciências em Serviço Utilizando o Diagrama v

Inicialmente, uma revisão de literatura sobre formação de professores em ciências foi realizada, onde foram elencadas problemáticas, identificados objetivos, referenciais teóricos e categorizadas as conclusões dos artigos selecionados. Esta revisão motivou a seguinte questão de pesquisa: como construir com professores de ciências, em encontros coletivos, reflexões sobre suas práticas no sentido da busca de autonomia, de forma a lidar com suas resistências e tensões para desenvolver estratégias que efetivamente conseguissem utilizar na sala de aula? Neste sentido, foi elaborada uma formação de professores com o objetivo de analisar um processo coletivo de formação contínua de professores em serviço, onde pudessem refletir sobre suas práticas, favorecendo o diálogo entre a teoria e a prática na construção e desenvolvimento do ato pedagógico. Durante o processo de formação foi utilizado o Diagrama V (descrito em detalhes no texto); não como uma metodologia, mas como ferramenta de auxílio nos processos educativos. A formação continuada envolveu cinco professores de ciências de escolas da rede municipal do município de Cachoeiro de Itapemirim ES, que se encontravam na presença e participação do pesquisador, discutindo e tecendo o curso em uma perspectiva formativa e colaborativa. Os encontros presenciais ocorreram durante um semestre letivo, intercalados com a realização de atividades de planejamento em casa e atividades com os alunos na escola. Para a coleta de dados, todos os encontros foram gravados e as falas dos professores transcritas. Além disso, foram coletados os Diagramas V produzidos pelos professores e pelos alunos. As impressões dos alunos em relação às atividades desenvolvidas também foram coletadas, através de falas espontâneas dos mesmos e de textos produzidos. Estes dados foram analisados qualitativamente através da análise de conteúdo e observando os Movimentos Crítico Reflexivos da pesquisa-ação, escolhida como opção teóricometodológica no contexto da formação continuada de professores. Refletir coletivamente, com a construção de Diagramas V com os alunos foi uma prática assumida pelos professores. Eles se inseriram em um caminho onde puderam ser pesquisadores de sua própria prática, puderam conhecer uma nova estratégia de ensino e reconhecer tanto a validade dessa proposta em seus contextos de sala de aula, quanto ao seu potencial pessoal para elaborar e desenvolver inovações no ensino, onde o conceito de Movimento Reflexivo Crítico foi tendo presença marcante na medida em que os ciclos foram avançando. E, finalmente, além de se propor um conceito de Professor Autônomo, no contexto da Formação de Professores, é sugerido, também, uma adaptação e ampliação do Diagrama V de Gowin (1981). Teríamos agora o Diagrama M, fazendo alusão ao Movimento Reflexivo Crítico discutido teoricamente e percebido na prática desse trabalho de doutorado

Genomic prediction and quantitative trait locus discovery in a cassava training population constructed from multiple breeding stages

Open Access Article; Published online: 11 Dec 2019Assembly of a training population (TP) is an important component of effective genomic selection‐based breeding programs. In this study, we examined the power of diverse germplasm assembled from two cassava (Manihot esculenta Crantz) breeding programs in Tanzania at different breeding stages to predict traits and discover quantitative trait loci (QTL). This is the first genomic selection and genome‐wide association study (GWAS) on Tanzanian cassava data. We detected QTL associated with cassava mosaic disease (CMD) resistance on chromosomes 12 and 16; QTL conferring resistance to cassava brown streak disease (CBSD) on chromosomes 9 and 11; and QTL on chromosomes 2, 3, 8, and 10 associated with resistance to CBSD for root necrosis. We detected a QTL on chromosome 4 and two QTL on chromosome 12 conferring dual resistance to CMD and CBSD. The use of clones in the same stage to construct TPs provided higher trait prediction accuracy than TPs with a mixture of clones from multiple breeding stages. Moreover, clones in the early breeding stage provided more reliable trait prediction accuracy and are better candidates for constructing a TP. Although larger TP sizes have been associated with improved accuracy, in this study, adding clones from Kibaha to those from Ukiriguru and vice versa did not improve the prediction accuracy of either population. Including the Ugandan TP in either population did not improve trait prediction accuracy. This study applied genomic prediction to understand the implications of constructing TP from clones at different breeding stages pooled from different locations on trait accuracy

Design of Multioctave High-Efficiency Power Amplifiers Using Stochastic Reduced Order Models

This paper presents a novel general design method of frequency varying impedance matching. The method is applied to design of a broadband high-efficiency power amplifier (PA). The proposed method defines the optimal impedance regions of a PA at several frequency sections over the operational frequency band. These regions contain the impedances that can achieve a high output power and a high-power added efficiency (PAE) simultaneously. A low-pass LC-ladder circuit is selected as the matching network (MN). The element values of the MN can be obtained using a synthesizing method based on stochastic reduced order models and Voronoi partition. The MN provides desired impedance in the predefined optimal impedance region at each frequency section. Thus, optimal output power and PAE of the PA can be achieved. To validate the proposed method, two eighth-order low-pass LC-ladder networks are designed as the input and output MNs, respectively. A gallium nitride (GaN) HEMT from Cree is employed as the active device. Packaging parasitic of the transistor has been taken into account. A PA is designed, fabricated, and measured. The measurement results show that the PA can achieve P1 dB PAE of better than 60% over a fractional bandwidth of 160% (0.2-1.8 GHz). The output power is 42-45 dBm (16-32 W), and the gain is 12-15 dB. The performance of the PA outperforms existing broadband highefficiency PAs in many aspects, which demonstrates the excellence of the proposed method

How are compassion fatigue, burnout, and compassion satisfaction affected by quality of working life? Findings from a survey of mental health staff in Italy

BACKGROUND: Quality of working life includes elements such as autonomy, trust, ergonomics, participation, job complexity, and work-life balance. The overarching aim of this study was to investigate if and how quality of working life affects Compassion Fatigue, Burnout, and Compassion Satisfaction among mental health practitioners. METHODS: Staff working in three Italian Mental Health Departments completed the Professional Quality of Life Scale, measuring Compassion Fatigue, Burnout, and Compassion Satisfaction, and the Quality of Working Life Questionnaire. The latter was used to collect socio-demographics, occupational characteristics and 13 indicators of quality of working life. Multiple regressions controlling for other variables were undertaken to predict Compassion Fatigue, Burnout, and Compassion Satisfaction. RESULTS: Four hundred questionnaires were completed. In bivariate analyses, experiencing more ergonomic problems, perceiving risks for the future, a higher impact of work on life, and lower levels of trust and of perceived quality of meetings were associated with poorer outcomes. Multivariate analysis showed that (a) ergonomic problems and impact of work on life predicted higher levels of both Compassion Fatigue and Burnout; (b) impact of life on work was associated with Compassion Fatigue and lower levels of trust and perceiving more risks for the future with Burnout only; (c) perceived quality of meetings, need of training, and perceiving no risks for the future predicted higher levels of Compassion Satisfaction. CONCLUSIONS: In order to provide adequate mental health services, service providers need to give their employees adequate ergonomic conditions, giving special attention to time pressures. Building trustful relationships with management and within the teams is also crucial. Training and meetings are other important targets for potential improvement. Additionally, insecurity about the future should be addressed as it can affect both Burnout and Compassion Satisfaction. Finally, strategies to reduce possible work-life conflicts need to be considered

Folk taxonomy and traditional management of cassava (Manihot esculenta Crantz) diversity in southern and central Benin

Cassava (Manihot esculenta Crantz) is an important food security crop for poor rural communities, particularly in Africa. At household level, cassava landraces used for cultivation are mainly selected based on farmers' interests, leading to very particular diversity evolution over generations. The structure, composition and factors influencing cassava diversity at that level is not well monitored and under documented. This study aimed at capturing and analyzing local knowledge on cassava genetic diversity and the key parameters affecting it in Benin, for better and sustainable local cassava genetic resources management. The methodological approach was based on field visits, interview using questionnaire and group discussion with farmers. Data were collected from one hundred and ninety eight (198) respondents and analyzed using descriptive statistics. The majority (82%) of the respondents were male, generally 20 to 80 years old. Positive correlation was found between cassava diversity maintained per household with cultivated area and household size (R2 = 0.162). Farmers used mainly stem and leaves characteristics to identify cassava varieties. Plant materials for next season were mostly selected according to the disease (mainly plant free of viral infection) status, size of the stem and number of nodes. The study revealed existence of a high diversity of cassava at the household level. However, various factors constrained cassava production and threats on cassava diversity were observed. Establishment of community field genebank, introduction of new varieties were some of the on-farm conservation strategies proposed by cassava farmers

Selection for resistance to cassava mosaic disease in African cassava germplasm using single nucleotide polymorphism markers

Cassava mosaic disease (CMD) is one of the main constraints that hamper cassava production. Breeding for varieties that are CMD resistant is a major aim in cassava breeding programmes. However, the use of the conventional approach has its limitations, including a lengthy growth cycle and a low multiplication rate of planting materials. To increase breeding efficiency as well as genetic gain of traits, SNP markers can be used to screen and identify resistant genotypes. The objective of this study was to predict the performance of 145 cassava genotypes from open-pollinated crosses for CMD resistance using molecular markers. Two SNP markers (S12_7926132 and S14_4626854), previously converted into Kompetitive allele-specific PCR (KASP) assays, as well as CMD incidence and severity scores, were used for selection. About 76% of the genotypes were revealed to be resistant to CMD based on phenotypic scores, while over 24% of the total population were found to be susceptible. Significant effects were observed for alleles associated with marker S12_7926132 while the other marker had nonsignificant effects. The predictive accuracy (true positives and true negatives) of the major CMD2 locus on chromosome 12 was 77% in the population used in this study. Our study provides insight into the potential use of marker-assisted selection for CMD resistance in cassava breeding programmes. Significance:• With an aim towards reducing the food insecurity rate in Africa, we report on the use of genetic tools for a fast and efficient release of new cassava varieties to benefit breeders, farmers and consumers, given the food and industrial importance of this staple crop.• This study adds tremendous knowledge to phenotypic and molecular screening for CMD resistance. The outcome will encourage breeders in various cassava breeding programmes to accelerate genetic gains as well as increase breeding accuracy and efficiency for CMD resistance

Genetic diversity and population structure of Striga hermonthica populations from Kenya and Nigeria

Article purchasedStriga hermonthica is a parasitic weed that poses a serious threat to the production of economically important cereals in sub-Saharan Africa. The existence of genetic diversity within and between S. hermonthica populations presents a challenge to the successful development and deployment of effective control technologies against this parasitic weed. Understanding the extent of diversity between S. hermonthica populations will facilitate the design and deployment of effective control technologies against the parasite. In the present study, S. hermonthica plants collected from different locations and host crops in Kenya and Nigeria were genotyped using single nucleotide polymorphisms. Statistically significant genetic differentiation (FST = 0.15, P = 0.001) was uncovered between populations collected from the two countries. Also, the populations collected in Nigeria formed three distinct subgroups. Unique loci undergoing selection were observed between the Kenyan and Nigerian populations and among the three subgroups found in Nigeria. Striga hermonthica populations parasitising rice in Kenya appeared to be genetically distinct from those parasitising maize and sorghum. The presence of distinct populations in East and West Africa and in different regions in Nigeria highlights the importance of developing and testing Striga control technologies in multiple locations, including locations representing the geographic regions in Nigeria where genetically distinct subpopulations of the parasite were found. Efforts should also be made to develop relevant control technologies for areas infested with ‘rice-specific’ Striga spp. populations in Kenya