4,854 research outputs found
Populational fluctuation and spatial distribution of Alphitobius diaperinus (Panzer) (Coleoptera; Tenebrionidae) in a poultry house, Cascavel, Parana state, Brazil.
Abstract Knowledge of the population fluctuation and spatial distribution of pests is fundamental for establishing an appropriate control method. The population fluctuation and spatial distribution of the Alphitobius diaperinus in a poultry house in Cascavel, in the state of Parana, Brazil, was studied between October, 2001 and October 2002. Larvae and adults of the lesser mealworm were sampled weekly using Arends tube traps (n = 22) for six consecutive flock grow-outs. The temperature of the litter and of the poultry house was measured at the same locations of the tube traps. Beetle numbers increased continuously throughout all the sampling dates (average 5,137 in the first week and 18,494 insects on the sixth week). Significantly greater numbers of larvae were collected than adults (1 to 20 times in 95% of the sampling points). There was no correlation between temperature and the number of larvae and adults collected, therefore no fluctuation was observed during the sampling period. The population growth was correlated to litter re-use. The highest temperatures were observed in deep litter. The spatial distribution of larvae and adults in the poultry house was heterogeneous during the whole period of evaluation. Results suggest that monitoring in poultry houses is necessary prior to adopting and evaluating control measures due to the great variability of the insect distribution in the poultry house. Keywords: lesser mealworm, poultry house, temperature, population dynamicbitstream/item/78871/1/ID-27879.pd
Surface alterations produced in grinding of austempered ductile iron
The technological advances achieved in recent decades have allowed to obtain cast parts of ductile iron with no metallurgical defects and of complex shapes and dimensions very close to the final ones. Heat treatments have enabled to obtain ADI within a wide range of mechanical properties. After properly choosing the processing variables, the most suitable combination of strength and toughness can be attained for each application. When restrictive dimensional or shape accuracy is required, a high precision machining process, such as grinding, is used. This process induces significant temperature gradients and surface plastic deformations which could affect the surface characteristics. The aim of this paper is to analyze the effects of grinding on power consumption, surface characteristics, roughness and distortion on ADI plates grade 2 and 5. The results indicate that it is possible to achieve excellent surface finishes with moderate power consumption and low residual stresses and distortions.Fil: Sosa, Amadeo Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂa de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa; ArgentinaFil: EcheverrĂa, M. D.. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Departamento de Mecanica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn en Ciencia y TecnologĂa de Materiales (i); Argentin
Causality re-established
Causality never gained the status of a "law" or "principle" in physics. Some
recent literature even popularized the false idea that causality is a notion
that should be banned from theory. Such misconception relies on an alleged
universality of reversibility of laws of physics, based either on determinism
of classical theory, or on the multiverse interpretation of quantum theory, in
both cases motivated by mere interpretational requirements for realism of the
theory. Here, I will show that a properly defined unambiguous notion of
causality is a theorem of quantum theory, which is also a falsifiable
proposition of the theory. Such causality notion appeared in the literature
within the framework of operational probabilistic theories. It is a genuinely
theoretical notion, corresponding to establish a definite partial order among
events, in the same way as we do by using the future causal cone on Minkowski
space. The causality notion is logically completely independent of the
misidentified concept of "determinism", and, being a consequence of quantum
theory, is ubiquitous in physics. In addition, as classical theory can be
regarded as a restriction of quantum theory, causality holds also in the
classical case, although the determinism of the theory trivializes it. I then
conclude arguing that causality naturally establishes an arrow of time. This
implies that the scenario of the "Block Universe" and the connected "Past
Hypothesis" are incompatible with causality, and thus with quantum theory: they
both are doomed to remain mere interpretations and, as such, not falsifiable,
similar to the hypothesis of "super-determinism". This article is part of a
discussion meeting issue "Foundations of quantum mechanics and their impact on
contemporary society".Comment: Presented at the Royal Society of London, on 11/12/ 2017, at the
conference "Foundations of quantum mechanics and their impact on contemporary
society". To appear on Philosophical Transactions of the Royal Society
Biologia e exigências térmicas do ácaro vermelho Tetranychus gigas Pritchard e Baker em soja.
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Selection for entomopathogenic fungi and LD50 of Metarhizium anisopliae (Metsch.) Sorok. for the Lesser Mealworm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae).
The pathogenicity of insect-pathogenic hyphomycetous isolates to the lesser mealworm Alphitobius diaperinus (Panzer) was tested in this study. Thirty isolates of Beauveria bassiana (Balsamo) Vuillemin, Paecilomyces amoenoroseus (Hennings), P. fumosoroseus (Wize) Brown& Smith, P. lilacinus (Thom) Samson, P. tenuipes (Petch) Samson, Metarhizium anisopliae (Metschnikoff) Sorokin, and M. anisopliae var. acridum were initially screened by sprinkling dry conidia onto adult A. diaperinus or by allowing adults to walk on Petri dishes with sporulating fungal isolates. The two most virulent isolates, CNPSo-Ma352 (M. anisopliae) and CNPSo-Ma356 (M. anisopliae), killed 30% and 26.7% of the dry-conidia treated adults, respectively. These two isolates were selected for LD50 bioassays. LD50 of CNPSo-Ma352 was 4.5 x 104 conidia per larva, and 2.1 x 105 conidia per adult, and for strain CNPSo-Ma356, LD50 was 2.2 x 104 conidia per larva and 1.3 x 105 conidia per adult. Larvae were 5-6 times more susceptible than adults. A larger number of conidia required to cause 50% mortality in insect evaluates, suggesting the reduced susceptibility of A. diaperinus to entomopathogenic fungi. Nevertheless, these and other strains of fungus offer an alternative method for controlling of lesser mealworm in poultry houses when associated to integrated management
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