30 research outputs found
Effects of temperature on the fitness of the alfalfa weevil (Hypera postica)
Background: Temperature directly influences the survival, development and reproduction of insects and limits their biological
activity. The alfalfa weevil (Hypera postica Gyllenhal) is a destructive pest of alfalfa crops in Spain and in most of the alfalfa production countries. The knowledge of how temperature affects the fitness of this pest can be used to predict its activity in current
or forecasted environmental conditions and to develop more accurate control strategies.
Results: We evaluated the fitness of alfalfa weevil at eight constant temperatures (8–36 °C) at 4 °C intervals by using life tables
and models for the description of temperature-dependent development rates. We found that most of the parameters we studied were temperature dependent. Development was observed at all temperatures. However, postembryonic survival was optimal at 16 °C but very low at 36 °C. Adults did not reproduce at 8, 32 or 36 °C. The highest fecundity and net reproductive rate
were observed at 20 °C, but the highest intrinsic rate of increase occurred at 24 °C. We predicted the phenology of the pest
based on the heat needed for development, the cumulative degree days from the beginning of October to the end of May,
and the day length in the study region.
Conclusion: Our prediction was validated using field data reporting the first occurrence of larval instars and adults, revealing
that no more than two generations are possible within an annual cycle. In a hypothetical case where average monthly temperatures increase by 1–2 °C, the number of generations would not changeSpecial thanks to Prof. Dr. Hsin Chi for helping us using TWOSEX life table software and for his comments to the manuscript. This project was funded by the Ministerio de Ciencia e Innovación of the Spanish Government (project AGL2017-84127-R). A.L-M. was funded by a Jade Plus Grant from the Universitat de Lleida and R.M. was funded by an FPI Grant from the Ministerio de Ciencia e Innovación of the Spanish Government. CONFLICT
Secador Convectivo Descontìnuo Para Secagem De Polpas Em Formato De Folhas
SECADOR CONVECTIVO DESCONTÍNUO PARA SECAGEM DE POLPAS EM FORMATO DE FOLHAS A presente invenção refere-se a um secador convectivo descontínuo, composto de porta-amostras telados em posição vertical para o suporte da polpa. O ar de secagem atravessa paralelamente as telas, juntamente com a polpa a ser seca. O secador foi desenvolvido para a secagem de qualquer tipo de polpa que possa ser seca em forma de folhas, sendo preferencialmente utilizado para a secagem da polpa de celulose fabricada a partir de fibras recuperadas para a obtenção de papel reciclado tipo cartão. Este invento pode ser utilizado por pequenas indústrias que façam a secagem de polpas, pequenas cooperativas ou ainda por produtores independentes de papel reciclado tipo cartão.BRPI0602099 (A)D21C9/18BR2006PI02099D21C9/1
Attractiveness of uninfested vegetables to the omnivorous predators Dicyphus bolivari and D. errans (Hemiptera: Miridae) and their relative suitability for oviposition
Conhecendo seus próprios talentos: jovens de escolas públicas em instituições de pesquisa no Rio de Janeiro Knowing one's own talents: public school youngsters in the research institutions of Rio de Janeiro
Intervenções educativas com a juventude merecem ser sempre analisadas e é isto a que nos propomos neste artigo. Trazemos uma reflexão que inicia por uma demarcação fundamental sobre como entendemos o jovem. Seguimos pela apresentação de um projeto específico - Jovens Talentos -, iniciação à ciência dirigida à parcela de estudantes da escola pública no estado do Rio de Janeiro, para que realizem atividades científicas, sob orientação de um pesquisador, freqüentando um determinado laboratório. Procuramos analisar como os que passam por essa experiência indicam compreendê-la. Essa iniciativa foi percebida como fundamental em questões relativas à independência e à autonomia do estudante, mostrando a relevância de ações educativas dirigidas a jovens.<br>Educational interventions related to youth always deserve being analyzed. This paper thus brings forward a reflection that begins with a fundamental delimitation of how we understand youngsters. It then presents a specific project - Jovens Talentos (Young Talents) - that initiates the students of public schools in the State of Rio de Janeiro to science. They perform scientific activities under the direction of a researcher and use a laboratory. We tried to analyze how the students that underwent this experience understand it. This initiative is held as fundamental in some issues related to the independence and autonomy of the student, which shows the importance of educational actions directed to youngsters
EFEITO DE DIFERENTES PROTOCOLOS DE DESCONGELAÇÃO SOBRE O SÊMEN CANINO CRIOPRESERVADO EM DILUIDOR À BASE ÁGUA DE COCO EM PÓ (ACP-106®)
It is known that temperature and thawing velocity can affect sperm quality during freeze-thawing procedures. Thus, the aim of this research was to compare different thawing protocols for canine semen extended in ACP-106® extender and cryopreserved. Ten ejaculates were collected from eight dogs and sperm rich fraction was evaluated regarding volume, concentration, motility, vigor, pH, morphology, acrosomal integrity and hyposmotic swelling test. Then, semen was extended in ACP-106® with 20% egg yolk and 6% glycerol, and frozen in 0.25 mL straws. After one week, one straw was thawed at 37°C/60s, another one at 55°C/5s and a third one at 75°C/8s, and the seminal characteristics were reevaluated. Similar results were observed for all the groups, except for sperm motility which was better preserved at 55°C/5s for up 30min than at 37°C/60s or 75°C/8s. From these results, it is concluded that canine semen extended in ACP -106® is better thawed at 55°C/5s