\u3ci\u3eAnaphes\u3c/i\u3e (Hymenoptera: Mymaridae) Reared from the Eggs of a Shore Fly (Diptera: Ephydridae)

Members of the family Mymaridae are obligate parasitoids of insect eggs, and some species attack the eggs of aquatic insects. Only one account of egg parasitism by the mymarid genus Anaphes on Diptera has been disclosed in the literature. Bakkendorf (1971) bred Anaphes autumnalis Foerster from an egg of Tipula autumnalis Loew

A Possible Case of Spatial Isolation in Brine Flies of the Genus \u3ci\u3eEphydra\u3c/i\u3e (Diptera: Ephydridae)

(excerpt) During the summer of 1975, adults and larvae of Ephydra riparia Fallen and E. cinerea Jones were encountered in the many brine pools occurring on the property of the Morton Salt Company at Rittman, Wayne County, Ohio (Scheiring and Foote, 1973). Larvae of both species have been reported to be salt tolerant (Bayly, 1972). E. ripariu larvae can survive in salinities up to 80°/oo (Sutcliffe, 1960), and the larvae of cinerea have been encountered by Nemenz (1960) in the Great Salt Lake of Utah at a salinity of 300°/oo

Cerebellar Complex Spike Firing Is Suitable to Induce as Well as to Stabilize Motor Learning

SummaryBackgroundCerebellar Purkinje cells (PC) generate two responses: the simple spike (SS), with high firing rates (>100 Hz), and the complex spike (CS), characterized by conspicuously low discharge rates (1–2 Hz). Contemporary theories of cerebellar learning suggest that the CS discharge pattern encodes an error signal that drives changes in SS activity, ultimately related to motor behavior. This then predicts that CS will discharge in relation to the error and at random once the error has been nulled by the new behavior.ResultsWe tested this hypothesis with saccadic adaptation in macaque monkeys as a model of cerebellar-dependent motor learning. During saccadic adaptation, error information unconsciously changes the endpoint of a saccade prompted by a visual target that shifts its final position during the saccade. We recorded CS from PC of the posterior vermis before, during, and after saccadic adaptation. In clear contradiction to the “error signal” concept, we found that CS occurred at random before adaptation onset, i.e., when the error was maximal, and built up to a specific saccade-related discharge profile during the course of adaptation. This profile became most pronounced at the end of adaptation, i.e., when the error had been nulled.ConclusionsWe suggest that CS firing may underlie the stabilization of a learned motor behavior, rather than serving as an electrophysiological correlate of an error

The subjective visual vertical in a nonhuman primate

We perceive the visual world as upright as our visual system used information on the orientation of the body to update the internal representation of the visual scene. In humans, this updating is not perfect, thus leading to distortions of the subjective visual vertical. For small roll-tilt angles (G60-), subjects overestimate the body tilt (E-effect), whereas for larger angles they underestimate it (A-effect). We wanted to know if monkeys show comparable perceptual distortions as they might help to identify the neural basis of a tilt-independent representation of visual objects at the level of single neurons. In order to answer this question, we trained two monkeys to align an arrow with an upright world-centered reference line whose visibility was varied between trials. Trials were performed at roll-tilt angles chosen from j90-to 90-. The monkeys' responses were precise for trials in which the reference line was visible. However, for the trials in which there was no reference line, their responses reflected an overestimation of body tilt (E-effect-like) very similar to humans. Our ability to demonstrate similar visuo-vestibular illusions in monkeys and man is an important step towards understanding the neural mechanism responsible for the perception of an upright visual world

Detection by NMR of a "local spin-gap" in quenched CsC60

We present a 13C and 133Cs NMR investigation of the CsC60 cubic quenched phase. Previous ESR measurements suggest that this phase is metallic, but NMR reveals contrasting electronic behavior on the local scale. The 13C spin-lattice relaxation time (T1) exhibits a typical metallic behavior down to 50 K, but indicates that a partial spin-gap opens for T<50 K. Unexpectedly, 133Cs NMR shows that there are two inequivalent Cs sites. For one of these sites, the NMR shift and (T1T)^{-1} follow an activated law, confirming the existence of a spin-gap. We ascribe this spin-gap to the occurrence of localized spin-singlets on a small fraction of the C60 molecules.Comment: 4 figure

Slepton pair production in the POWHEG BOX

We present an implementation for slepton pair production at hadron colliders in the POWHEG BOX, a framework for combining next-to-leading order QCD calculations with parton-shower Monte-Carlo programs. Our code provides a SUSY Les Houches Accord interface for setting the supersymmetric input parameters. Decays of the sleptons and parton-shower effects are simulated with PYTHIA. Focussing on a representative point in the supersymmetric parameter space we show results for kinematic distributions that can be observed experimentally. While next-to-leading order QCD corrections are sizable for all distributions, the parton shower affects the color-neutral particles only marginally. Pronounced parton-shower effects are found for jet distributions.Comment: 10 pages, 4 figure

Myc depletion induces a pluripotent dormant state mimicking diapause

Mouse embryonic stem cells (ESCs) are maintained in a naive ground state of pluripotency in the presence of MEK and GSK3 inhibitors. Here, we show that ground-state ESCs express low Myc levels. Deletion of both c-myc and N-myc (dKO) or pharmacological inhibition of Myc activity strongly decreases transcription, splicing, and protein synthesis, leading to proliferation arrest. This process is reversible and occurs without affecting pluripotency, suggesting that Myc-depleted stem cells enter a state of dormancy similar to embryonic diapause. Indeed, c-Myc is depleted in diapaused blastocysts, and the differential expression signatures of dKO ESCs and diapaused epiblasts are remarkably similar. Following Myc inhibition, pre-implantation blastocysts enter biosynthetic dormancy but can progress through their normal developmental program after transfer into pseudo-pregnant recipients. Our study shows that Myc controls the biosynthetic machinery of stem cells without affecting their potency, thus regulating their entry and exit from the dormant state.This work was supported by the FOR2033 and SFB873 funded by the Deutsche Forschungsgemeinschaft (DFG), the Dietmar Hopp Foundation (all to A.T.), and the Wellcome Trust (to A.S.)

Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L−1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure