Domatia reduce larval cannibalism in predatory mites

1. Acarodomatia are small structures on the underside of leaves of many plant species, which are mainly inhabited by carnivorous and fungivorous mites. 2. Domatia are thought to protect these mites against adverse environmental conditions and against predation. They are considered as an indirect plant defence; they provide shelter to predators and fungivores and these in turn protect the plants against herbivores and fungi. 3. We studied the possible role of domatia of coffee (Coffea arabica L.) (Rubiaceae) and sweet pepper (Capsicum annum L.) (Solanaceae) in reducing cannibalism in the mites inhabiting the domatia. We measured cannibalism of larvae by adults of the predatory mites Iphiseiodes zuluagai Denmark & Muma and Amblyseius herbicolus Chant on coffee leaf discs and of the predatory mite Iphiseius degenerans (Berl.) on sweet pepper leaf. Domatia were closed with glue or left open. 4. Cannibalism in all three species increased when domatia were closed. With I. degenerans, moreover, we found that the previous diet of the cannibal attenuated the effect of domatia on cannibalism. 5. We conclude that domatia can protect young predatory mites against cannibalism by adults and that the diet of cannibals affects the rate of cannibalism

On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes

The sensitivity of a search for sources of TeV neutrinos can be improved by grouping potential sources together into generic classes in a procedure that is known as source stacking. In this paper, we define catalogs of Active Galactic Nuclei (AGN) and use them to perform a source stacking analysis. The grouping of AGN into classes is done in two steps: first, AGN classes are defined, then, sources to be stacked are selected assuming that a potential neutrino flux is linearly correlated with the photon luminosity in a certain energy band (radio, IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino production in AGN, this correlation is motivated by hadronic AGN models, as briefly reviewed in this paper. The source stacking search for neutrinos from generic AGN classes is illustrated using the data collected by the AMANDA-II high energy neutrino detector during the year 2000. No significant excess for any of the suggested groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic

Poor sleep quality and progression of gait impairment in an incident Parkinson’s disease cohort

Abnormal sleep may associate with cognitive decline in Parkinson’s disease (PD). Furthermore, sleep dysfunction may associate with worse motor outcome. We hypothesised that PD patients with poor quality sleep would have greater progression in gait dysfunction, due to structural and functional overlap in networks subserving sleep and gait regulation. 12 PD patients and 12 age-matched controls completed longitudinal follow-up over 36 months. Poor sleep efficiency and greater sleep fragmentation correlated significantly with progression of step-width variability, a gait characteristic mediated by postural control, providing evidence that poor sleep in PD is associated with a more rapid deterioration in gait