14 research outputs found
Diversidade de Parasitóides (Hymenoptera: Braconidae e Figitidae) de larvas frugívoras (Diptera: Tephritidae e Lonchaeidae) na Reserva Florestal Adolpho Ducke, Amazônia Ocidental, Manaus, Brasil
This study aimed to identify parasitoid species of frugivorous larvae and to describe the tritrophic interactions involving wild fruits, frugivorous insects and their natural enemies at Adolpho Ducke Forest Reserve (RFAD) (Manaus, AM, Brazil). Collections were performed in four 1 km2 quadrants in the corners of the RFAD. The wild fruits were collected inside the forest in access trails leading to each collection area and in trails that surrounded the quadrants, up to five metres from the trail on each side. The fruits were placed in plastic containers covered with thin fabric, with a vermiculite layer on the base to allow the emergence of flies or parasitoids. Seven Braconidae species were collected, distributed among Opiinae: Doryctobracon areolatus (Szépligeti, 1911), Utetes anastrephae (Viereck, 1913), and Opius sp., and Alysiinae: Asobara anastrephae (Muesebeck, 1958), Phaenocarpa pericarpa Wharton and Carrejo, 1999, Idiasta delicata Papp, 1969, and Asobara sp. Parasitism rates by braconids and figitids are presented. Doryctobracon areolatus was the most frequent, parasitizing the highest number of fly species, and showing the highest parasitism percentage in larvae feeding on Micropholis williamii fruits. The collected figitids belong to Aganaspis nordlanderi Wharton, 1998 and A. pelleranoi (Brethes, 1924). All 15 tritrophic associations are new records for the Brazilian Amazon region. The RFAD is an important natural reservoir of frugivorous larvae parasitoids
Relationship between PPI and baseline startle response
Prepulse inhibition (PPI) of the startle response to a sudden noise is the reduction in startle observed when the noise is preceded shortly by a mild sensory event, which is often a tone. A part of the literature is based on the assumption that PPI is independent of the baseline startle. A simple model is presented and experimental validation provided. The model is based on the commonly accepted observation that the neuronal circuit of PPI differs from that of startle. But, by using a common output, the measures of both phenomena become linked to each other. But, how can we interpret the numerous experimental data showing PPI to be independent of the startle level? It is suggested that in a number of such cases the baseline startle would have been stabilized by a ceiling effect in the startle/PPI neuronal networks. Reducing the startle level, for example in a PPI evaluation procedure, may disclose properties of startle masked by this ceiling effect. Disclosure of habituation to the startle eliciting noise produced an increase of PPI along its initial measurements. Taken together, even if the neuronal process that sustains startle and PPI are distinct, separating them experimentally requires careful parametric methods and caution in the interpretation of the corresponding observations
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure