1,162 research outputs found
Coexistence of predators in time: Effects of season and prey availability on species activity within a Mediterranean carnivore guild
The degree of coexistence among predators can determine the structure of ecological communities. Niche partitioning is a common strategy applied by species to enhance their coexistence. Diet, habitat, or time use can be responsible for segregation among carnivore species, the latter factor being the least studied in Mediterranean ecosystems. Terrestrial medium‐sized carnivores (i.e., mesocarnivores) carry out important functions in ecosystems, and identifying their interactions is essential for their conservation.
In this study, we explore the activity of a terrestrial mesocarnivore guild in order to determine seasonal differences in daily activity patterns of competitors and prey. We also investigate how the abundance of a common mesocarnivore prey in the region, small mammals, influences the activity of predators.
During a year, camera trap devices (n = 18) were installed in Montseny Natural Park (Catalan Pre‐Coastal Range, North‐East Iberian Peninsula), a region that hosts five mesocarnivore species. Camera trapping detections were used to estimate their daily activity patterns and corresponding overlaps. We also surveyed small mammal plots (n = 5) in order to calculate prey abundance and test its effect on the relative activity of each carnivore species.
Despite all target mesocarnivores are mainly nocturnal, the activity overlap among them varies according to species particularities and season. Red fox (Vulpes vulpes) appears as a generalist species in terms of time use, whereas stone marten (Martes foina) and genet (Genetta genetta) show the most similar activity patterns and both of them seem to be positively influenced by small mammal abundance. Overall, the diversity found in the way mesocarnivore species use time could facilitate their coexistence.
Despite activity pattern similarities among carnivore species should not be directly translated to negative interactions, they can have a strong influence in habitat and resource‐limited ecosystems. Therefore, activity overlaps should be taken into account when discussing wildlife management actions
Sobrevivência e ganho de peso da lagarta-do-cartucho do milho (LCM), Spodoptera frugiperda (Smith) (Lep.: Noctuidae), alimentadas em seções de folhas de milho Bt.
Atividade biológica das toxinas do Bt, Cry 1A(b) e Cry 1F em Spodoptera frugiperda (Smith) (Lepidoptera: noctuidae).
Atualmente, há duas diferentes toxinas do Bacillus thuringiensis (Bt) disponíveis em milho transgênico. Entretanto, há poucas informações sobre a toxicidade dessas proteínas puras Cry 1A(b) e Cry 1F para a lagarta-do-cartucho do milho (LCM), Spodoptera frugiperda, (Smith) usando o método de tratamento superficial da dieta. Os bioensaios foram conduzidos, usando um gradiente de concentração para as duas toxinas. Cada tratamento foi infestado artificialmente com larvas da LCM recém-eclodidas e mantidas sob temperatura constante e no escuro. Dez dias após a infestação, o número de larvas sobreviventes e a inibição de crescimento baseado na biomassa foram avaliados. Os dados de mortalidade foram submetidos à análise de "Probit". As CL50 estimadas para Cry1A(b) e Cry1F foram, respectivamente, 689,81 ng/cm2 e 36,46 ng/cm2. A CL50 foi suficiente para inibir o acúmulo de biomassa das larvas em 91,61% e 89,81% para Cry1Ab e Cry1F, respectivamente. As larvas que sobreviveram por dez dias nas dietas tratadas com o Cry 1A(b) foram transferidas para dieta não tratadas e observadas até a emergência dos adultos. Das larvas sobreviventes, 62,8% recuperaram seu desenvolvimento, acumulando a biomassa de uma pupa normal. Portanto, a atividade biológica da toxina do Bt vai além da simples toxicidade, incluindo uma significativa inibição de alimentação. Esse fato tem implicações importantes para o desenvolvimento de estratégias para o manejo da resistência
Isolamento e caracterização de bactérias endofíticas não patogênicas em milho.
bitstream/item/58846/1/Pesq.And.-31-1.pd
Caracterização de bactérias endofíticas isoladas de genótipos de milho com potencial de utilização no controle de insetos.
Characterisation of AMS H35 HV-CMOS monolithic active pixel sensor prototypes for HEP applications
Monolithic active pixel sensors produced in High Voltage CMOS (HV-CMOS)
technology are being considered for High Energy Physics applications due to the
ease of production and the reduced costs. Such technology is especially
appealing when large areas to be covered and material budget are concerned.
This is the case of the outermost pixel layers of the future ATLAS tracking
detector for the HL-LHC. For experiments at hadron colliders, radiation
hardness is a key requirement which is not fulfilled by standard CMOS sensor
designs that collect charge by diffusion. This issue has been addressed by
depleted active pixel sensors in which electronics are embedded into a large
deep implantation ensuring uniform charge collection by drift. Very first small
prototypes of hybrid depleted active pixel sensors have already shown a
radiation hardness compatible with the ATLAS requirements. Nevertheless, to
compete with the present hybrid solutions a further reduction in costs
achievable by a fully monolithic design is desirable. The H35DEMO is a large
electrode full reticle demonstrator chip produced in AMS 350 nm HV-CMOS
technology by the collaboration of Karlsruher Institut f\"ur Technologie (KIT),
Institut de F\'isica d'Altes Energies (IFAE), University of Liverpool and
University of Geneva. It includes two large monolithic pixel matrices which can
be operated standalone. One of these two matrices has been characterised at
beam test before and after irradiation with protons and neutrons. Results
demonstrated the feasibility of producing radiation hard large area fully
monolithic pixel sensors in HV-CMOS technology. H35DEMO chips with a substrate
resistivity of 200 cm irradiated with neutrons showed a radiation
hardness up to a fluence of ncm with a hit efficiency of
about 99% and a noise occupancy lower than hits in a LHC bunch
crossing of 25ns at 150V
Selection of the fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) for survival on Cry 1A (b) Bt toxin.
Plantas transgênicas que expressam toxinas da bactéria Bacillus thuringiensis (Bt) representam um importante avanço para o controle de lepidópteros-pragas de milho. Híbridos de milho Bt expressando a toxina Cry1A(b) têm mostrado significativo nível de resistência à lagarta-do-cartucho (LCM), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), embora larvas dessa espécie tenham sido observadas em campo e em laboratório sobrevivendo nesses híbridos. Resistência de S. frugiperda também tem sido registrada para diferentes inseticidas. Em bioensaios, seleção de insetos sobreviventes mostrou um aumento do nível de tolerância à toxina do Bt Cry1A(b) em populações da lagarta-do-cartucho, após quatro gerações, indicando que essa tolerância é herdada. Palavras-chave: Insecta, resistência, plantas transgênicas
Nota sobre reptiles ibéricos: III. Estudio preliminar sobre biometría y distribución de Elaphe longissima (Laur, 1768) en la península Ibérica. (Reptilia Colubridae)
Visual Performance of Tecnis ZM900 Diffractive Multifocal IOL after 2500 Implants: A 3-Year Followup
Purpose. To evaluate visual performance for near, intermediate, and distant vision; complaints of photic phenomena, and patient satisfaction with the new diffractive multifocal IOL used in eyes which underwent phacoemulsification. Methods. Two thousand and five hundred consecutive eyes undergoing Tecnis ZM900 multifocal IOL implantation were included in this retrospective analysis. The minimum followup of 3 months was required after the surgery. Patients were assessed for uncorrected near visual acuity (UNVA) at a fixed distance (33 cm), uncorrected intermediate visual acuity (UIVA) at 60 cm, and uncorrected distance visual acuity (UDVA). Using a subjective questionnaire, patients satisfaction, their independence from using glasses, and the perception of glare and halo phenomena were also evaluated at the last follow-up. Results. Two thousand and five hundred eyes of 1558 patients underwent cataract surgery and Tecnis ZM900 multifocal IOL implantation. Four hundred and eighty seven patients (31.3%) were men, and 1071 (68.7%) were women. The mean age of the patients was 66.17 years. A UDVA of 20/30 or better was achieved by 85% of eyes. A UNVA of J1 was achieved by 93.7% of eyes and that of J2 or better was achieved by 98%. A UIVA of J4 or better was achieved by 65% and J5 or better was achived by more than 82.8% of the eyes in the study. Glare and halos were reported as severe by only 6.1% and 2.12% of patients, respectively. Ninety seven percent reported complete spectacle independence and 88% stated that they are totally satisfied with their quality of vision and would choose to have the same lens implanted again after the first implant. Five percent of the eyes in the study needed a second procedure (enhancement) to achieve a better visual result. No patient underwent lens exchange. Conclusion. Excellent near, intermediate, and distant vision was observed in patients implanted with the Tecnis ZM900 diffractive multifocal IOL. Spectacle independence and a minimum occurrence of photic phenomena make this IOL an excellent option in patients with cataract
Resistance of commercial hybrids and lines of sorghum, Sorghum bicolor (L.) Moench., to Diatraea saccharalis (Fabr.) (Lepidoptera: Pyralidae).
Híbridos comerciais e uma coleção de linhagens de sorgo da Embrapa, foram avaliados quanto a resistência à broca de cana-de-açúcar, Diatraea saccharalis (Fabr.). Dois experimentos foram instalados no campo de Sete Lagoas, MG, na época da "safrinha", em blocos casualizados, com três repetições e conduzidos sob infestação natural. As plantas foram avaliadas quanto ao estande, ciclo, altura e número de galerias, o número total de internóides e o número de internóides danificados para o calculo do Índice de Infestação (II) e ìndice de Intensidade de Infestação (III). Entre os hibridos comerciais, BR 304 e CMSXS9701 apresentaram os menores II enquanto que Z 732 e Esmeralda destacaram-se com os menores III. Entre as linhagens, 9815017 apresentou o menor II, e 9816003 o menor II. Os dois índices correlacionaram-se positivamente com a altura das plantas nos dois ensaios e negativamente com o ciclo das linhagens. Entretanto, nenhuma correlação foi observada entre eles no ensaio. Embora exista variabilidade genética entre os híbridos comerciais de sorgo para resistência e broca da cana, sob altas infestações, perdas significativas nas produtividades poderão ocorrer em todos os híbridos avaliados. Por outro lado, a variabilidade genética observada entre as linhagens de sorgo indicaram um grande potencial para a seleção de cultivares resistentes nos programas de melhoramento
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