História das ideias sobre circulação sanguínea : concepções de professores de Biologia

Os currículos escolares brasileiros e as diretrizes para a formação de professores de Ciências Biológicas recomendam o ensino de História e Filosofia da Ciência. No entanto, pesquisas mostram que a temática está pouco presente nos cursos de formação inicial e continuada de professores e nas aulas de Ciências da educação básica. Desse modo, o presente estudo investigou as concepções de professores sobre a história da circulação sanguínea, em um curso de formação continuada. Os resultados mostram que embora alguns docentes apresentem conhecimentos superficias sobre o tema, grande parte não conhece os principais estudiosos, os métodos utilizados e o contexto de desenvolvimento desses estudos. Isso pode se refletir nas aulas de Ciências, uma vez que elas privilegiam o produto final do conhecimento científico e nas visões distorcidas discentes sobre a natureza da Ciência

Itinerância, intensificação e condições de trabalho de professores de educação física escolar como condicionante de motivação e bem-estar docente

BACKGROUND: The increasing demands of teaching work and itinerancy among schools trigger processes of intensification and precariousness of the teacher working conditions. OBJECTIVE: To analyze situations of itinerancy, intensification and working conditions and their consequences to the motivation, career development, and welfare of Physical Education teachers from a municipality in the west of Parana State, Brazil. METHODS: It is a qualitative, cross-sectional, and descriptive study developed with ten physical education teachers from state and municipal public schools. A socio-demographic questionnaire for the characterization of the participants and a semi-structured interview were used in the data collection, with a script referring to the working circumstances, and its relations to itinerancy among schools and intensification of teaching work. The results were analyzed based upon the content analysis plan proposed by Bardin (2011). RESULTS: The study collected data that evidence the motivation for teaching, despite the manifestations of job instability, the need for travelling among schools and the limitation and fragmentation of their professional attributions. Such obstacles emerge as triggers of the intensification, limitation, and fragmentation of teaching work, being a determining factor for excessive stress, misadjustments in the work environment, in the way of coping with professional demands, and career development. CONCLUSION: The itinerancy of teachers among schools accentuates the intensification and precariousness of teaching work, with the potential to impact on their motivation and well-being.INTRODUÇÃO: As crescentes demandas do trabalho docente, a itinerância entre escolas desencadeiam processos de intensificação e precarização da função laboral docente. OBJETIVO: Analisar situações de itinerância, intensificação e condições de trabalho e suas consequências à motivação, carreira e condições de bem-estar de um grupo de professores de Educação Física de um município do extremo oeste do Estado do Paraná, Brasil. MÉTODOS: É um estudo qualitativo, de corte transversal e de cunho descritivo desenvolvido com dez professores de Educação Física de escolas públicas estaduais e municipais de um município do extremo oeste do Estado do Paraná. Foram utilizados na coleta de dados um questionário sociodemográfico para caracterização dos participantes e uma entrevista semiestruturada, com roteiro referente às condições laborais e suas relações com itinerância entre escolas e intensificação do trabalho docente. As análises dos resultados foram realizadas com base no plano de análise de conteúdo proposto por Bardin (2011). RESULTADOS: O estudo levantou dados que evidenciam a motivação para a docência, embora as manifestações de instabilidade de vínculo empregatício, a constante necessidade de itinerância entre escolas e a limitação e fragmentação de suas atribuições profissionais. Tais entraves aparecem como desencadeantes da intensificação, limitação e fragmentação do trabalho docente sendo fator determinante para o estresse excessivo, desajuste no nível de integração com ambiente de trabalho, no modo com que enfrentamento de demandas profissionais e desenvolvimento na carreira. CONCLUSÃO: A itinerância dos professores entre escolas acentua um quadro de intensificação e precarização do trabalho docente, com potencialidade para impactar em sua motivação e bem-estar docente

Beyond trees: Mapping total aboveground biomass density in the Brazilian savanna using high-density UAV-lidar data

Tropical savanna ecosystems play a major role in the seasonality of the global carbon cycle. However, their ability to store and sequester carbon is uncertain due to combined and intermingling effects of anthropogenic activities and climate change, which impact wildfire regimes and vegetation dynamics. Accurate measurements of tropical savanna vegetation aboveground biomass (AGB) over broad spatial scales are crucial to achieve effective carbon emission mitigation strategies. UAV-lidar is a new remote sensing technology that can enable rapid 3-D mapping of structure and related AGB in tropical savanna ecosystems. This study aimed to assess the capability of high-density UAV-lidar to estimate and map total (tree, shrubs, and surface layers) aboveground biomass density (AGBt) in the Brazilian Savanna (Cerrado). Five ordinary least square regression models esti-mating AGBt were adjusted using 50 field sample plots (30 m × 30 m). The best model was selected under Akaike Information Criterion, adjusted coefficient of determination (adj.R2), absolute and relative root mean square error (RMSE), and used to map AGBt from UAV-lidar data collected over 1,854 ha spanning the three major vegetation formations (forest, savanna, and grassland) in Cerrado. The model using vegetation height and cover was the most effective, with an overall model adj-R2 of 0.79 and a leave-one-out cross-validated RMSE of 19.11 Mg/ha (33.40%). The uncertainty and errors of our estimations were assessed for each vegetation formation separately, resulting in RMSEs of 27.08 Mg/ha (25.99%) for forests, 17.76 Mg/ha (43.96%) for savannas, and 7.72 Mg/ha (44.92%) for grasslands. These results prove the feasibility and potential of the UAV-lidar technology in Cerrado but also emphasize the need for further developing the estimation of biomass in grasslands, of high importance in the characterization of the global carbon balance and for supporting integrated fire management activities in tropical savanna ecosystems. Our results serve as a benchmark for future studies aiming to generate accurate biomass maps and provide baseline data for efficient management of fire and predicted climate change impacts on tropical savanna ecosystems

Detection and identification of Xanthomonas pathotypes associated with citrus diseases using comparative genomics and multiplex PCR.

Background. In Citrus cultures, three species of Xanthomonas are known to cause distinct diseases. X. citri subsp. citri patothype A, X. fuscans subsp. aurantifolii pathotypes B and C, and X. alfalfae subsp. citrumelonis, are the causative agents of cancrosis A, B, C, and citrus bacterial spots, respectively. Although these species exhibit different levels of virulence and aggressiveness, only limited alternatives are currently available for proper and early detection of these diseases in the fields. The present study aimed to develop a new molecular diagnostic method based on genomic sequences derived from the four species of Xanthomonas. Results. Using comparative genomics approaches, primers were synthesized for the identification of the four causative agents of citrus diseases. These primers were validated for their specificity to their target DNA by both conventional and multiplex PCR. Upon evaluation, their sensitivity was found to be 0.02 ng/?l in vitro and 1.5 ? 104 CFU ml?1 in infected leaves. Additionally, none of the primers were able to generate amplicons in 19 other genomes of Xanthomonas not associated with Citrus and one species of Xylella, the causal agent of citrus variegated chlorosis (CVC). This denotes strong specificity of the primers for the different species of Xanthomonas investigated in this study. Conclusions. We demonstrated that these markers can be used as potential candidates for performing in vivo molecular diagnosis exclusively for citrus-associated Xanthomonas. The bioinformatics pipeline developed in this study to design specific genomic regions is capable of generating specific primers. It is freely available and can be utilized for any other model organism

The Genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

Contributions Of The Persistent Sodium And M-Type Potassium Currents In The Prebötzinger Complex For Breathing Rhythm Generation

Vertebrate animals execute different rhythmic motor behaviors such as walking, swallowing, and breathing, and the generation of that rhythmic activity is governed by central pattern generator network (CPGs), which do not require sensory feedback. The central nervous system is endowed with different CPGs are responsible for determining the appropriate sequence of muscle activation that leads to the correct behavior expression. Breathing is an essential rhythmic behavior and drives the gas exchange between the lungs and the ambient air. Unlike most CPGs that are episodic, and generally quiescent in resting conditions, the respiratory network is active continuously throughout life. The normal breathing cycle is composed by two distinct phases: inspiration and expiration. Inspiration is the inexorable phase and happens due to the active recruitment of the diaphragmatic muscle, while expiration happens passively due to the elastic recoil of the diaphragm and thorax. The CPG for inspiratory activity is the preBötzinger complex (preBötC) in the lower brainstem, and it contains essential excitatory interneurons derived from neuronal progenitor cells that express the Developing brain homeobox 1 (Dbx1) transcription factor. However, the ion channel mechanisms involved in initiating and terminating rhythmic burst activity in vivo remain unsolved. Here, I test the ion channels proposed to orchestrate both mechanisms. The first chapter of my thesis evaluates the “pacemaker theory” which suggests that some preBötC neurons express an intrinsic persistent sodium current (INaP) that gives rise to the voltage-dependent bursting-pacemaker activity, thus driving the inspiratory bursts. I knocked out and knocked down the Scn8a that codes for the sodium channel NaV1.6 which gives rise to INaP. I showed that pacemaker activity is no longer present in rhythmic slices of preBötC from neonatal mice; further, juvenile, and adult mice lacking this subunit still generate breathing activity. The second chapter seeks to understand the role of the M-currents in inspiratory burst termination and opioid-induced respiratory depression. Previous experiments showed that pharmacological blockage of voltage-gated potassium channels from the KV7 family prolongs bursts in a rhythmic slice model of breathing. Surprisingly, I found that genetic knockdown of Kcnq2 and Kcnq3 that comprise M-current does not alter ventilation, metabolis and breathing variability of adult mice. I conclude that Scn8a-mediated NaV1.6 channels underlies INaP-driven pacemaker activity in rhythmic slices, and although it contributes to neuronal excitability in preBötC, this feature is dispensable for rhythm generation. Moreover, Kcnq2/Kcnq3-mediated KV7 M-currents are not necessary for inspiration-expiration phase transition in vivo. These results contribute to understanding the role of specific ion channels in breathing control by using cutting-edge genetic tools, while avoiding unwanted side-effects observed in conventional pharmacological approaches. Moreover, this work shows the importance of whole animals to understand the multifaceted origin of vital motor behaviors like breathing, which was a missing information not achieved with the use of reduced preparations

História das ideias sobre circulação sanguínea : concepções de professores de Biologia

Os currículos escolares brasileiros e as diretrizes para a formação de professores de Ciências Biológicas recomendam o ensino de História e Filosofia da Ciência. No entanto, pesquisas mostram que a temática está pouco presente nos cursos de formação inicial e continuada de professores e nas aulas de Ciências da educação básica. Desse modo, o presente estudo investigou as concepções de professores sobre a história da circulação sanguínea, em um curso de formação continuada. Os resultados mostram que embora alguns docentes apresentem conhecimentos superficias sobre o tema, grande parte não conhece os principais estudiosos, os métodos utilizados e o contexto de desenvolvimento desses estudos. Isso pode se refletir nas aulas de Ciências, uma vez que elas privilegiam o produto final do conhecimento científico e nas visões distorcidas discentes sobre a natureza da Ciência

CAN GENETIC VARIATIONS IN THE DEPLETION PROCESS OF STARCH STOCKS BE DRIVING CONTEMPORARY MICROEVOLUTION IN Toona ciliataVAR. australis?

A simple method to establish a relationship between physiological responses of plants and thermal stresses is by quantifying the number of parenchyma cells with remaining starch stocks. The knowledge of the dynamic of starch depletion can be achieved by using statistical models such as thermal performance curves (TPC). The aim of this study was to quantify radial parenchyma cells with remaining starch stocks in order to evaluate changes in TPC regarding increases in temperature over seedlings of Toona ciliata (Australian Red cedar), in different heat induced treatments of matching both exposure time and temperature; besides of the assessment of variations in the TPC’s and also to understand whether these changes are over genetic control. We used a protocol of heat induced treatment in the stems of the seedlings, anatomical cuts and staining with neutral red for the commercial clone BV1120, which was used as template to fit polynomial curves of TPC. After these mathematical fits and validation of these models with lignotubers of Eucalyptus urophylla, we defined a depletion time of 50% (TD50) from the starch stocks for each thermal treatment, so we could compare the performance for the others five commercial clones: BV1110, BV1121, BV1151, BV1210 and BV1321. The R2 values were all above 85%. Results indicated that clone BV1110 had the highest value for remaining starch stocks at all heat induced treatments, in contrast to the clone BV1210, which had the lowest values for remaining starch stocks. The variation of the starch content indicates high values of broad-sense heritability, ranging from 97,43 to 98,48%, suggesting a possible contemporary microevolution process undergoing in Australian Red cedar. Thus, further selections can help improving the tolerance of Australian Red cedar to increasing temperatures on the environment

Análise de Sinais de Emissao Acústica e Estatística Counts na Detecção da Alteração Microestrutural na Retificação de Aço 1045

Grinding is a high-precision, high-value-added finishing process as it is usually the last stage of the manufacturing chain. However, unsatisfactory results may occur, mainly due to changes in the microstructure of the ground workpiece. Such changes are caused by the high temperatures involved in the process due to the grinding conditions in which the part was subjected. In this way, the main objective of this work is the monitoring of the grinding process in order to detect changes in the signal and to relate them with damage occurred in the ground workpiece. The tests were carried out on a surface grinding machine, aluminum oxide grinding wheel and ABNT 1045 steel parts. Metallography was performed on the parts for a more further analysis of their microstructure. The recording of signals was obtained at a sample rate of 2 MHz through an acoustic emission sensor (AE). A frequency study for the selection of the best frequency bands that characterize damage occurred in the ground workpiece. The event counts statistic was applied to the filtered signal in the chosen frequency bands. The results of this work show that the grinding conditions influence the signal and, therefore, its frequency spectrum.Keywords: Manufacturing process; automation, monitoring; grinding process; acoustic emission, damage detectio