Radio Halo and Relic Candidates from the NRAO VLA Sky Survey

We present the first results of the search of new halo and relic candidates in the NRAO VLA Sky Survey. We have inspected a sample of 205 clusters from the X-ray-brightest Abell-type clusters presented by Ebeling et al (1996), and found 29 candidates. Out of them, 11 clusters are already known from the literature to contain a diffuse cluster-wide source, while in 18 clusters this is the first indication of the existence of this type of sources. We classify these sources as halos or relics according to their location in the cluster center or periphery, respectively. We find that the occurrence of cluster halos and relics is higher in clusters with high X-ray luminosity and high temperature. We also confirm the correlation between the absence of a cooling flow and the presence of a radio halo at the cluster center.Comment: 25 Pages, 4 Figures included in the text, Figures 3a to 3g in separated files. New Astronomy in pres

Effects of a primary rehabilitation programme on arterial vascular adaptations in an individual with paraplegia

AbstractObjectiveEvaluation of the effects of 6 weeks of wheelchair endurance training on arterial stiffness in an individual with paraplegia.MethodsA 22-year-old male patient with complete (ASIA A) paraplegia (T11) was tested before and after training (30minutes three times per week). Physical performance and cardiorespiratory response were evaluated during a maximal progressive test. Heart rate (HR), blood pressure, stroke volume and arterial carotid–wrist and carotid–ankle pulse wave velocity (PWV) were measured at rest.ResultsMaximal responses registered (maximal tolerated power, V˙O2 peak) during the exercise test were increased after training. At rest, HR as PWV decreased, whereas cardiac output and blood pressure remained constant.ConclusionContinuous exposure of the subject to a repeated high intensity exercise bout for 6 weeks elevated fitness level. Such a regular practice might also constitute a major way to trigger vascular remodelling beyond to the trained body part

The reaction of Pseudomonas nitrite reductase and nitrite. A stopped-flow and EPR study.

The reaction between reduced Pseudomonas nitrite reductase and nitrite has been studied by stopped-flow and rapid-freezing EPR spectroscopy. The interpretation of the kinetics at pH 8.0 is consistent with the following reaction mechanism (where k1 and k3 much greater than k2). [formula: see text] The bimolecular step (Step 1) is very fast, being lost in the dead time of a rapid mixing apparatus; the stoichiometry of the complex has been estimated to correspond to one NO2- molecule/heme d1. The final species is the fully reduced enzyme with NO bound to heme d1; and at all concentrations of nitrite, there is no evidence for dissociation of NO or for further reduction of NO to N2O. Step 2 is assigned to an internal electron transfer from heme c to reduced NO-bound heme d1 occurring with a rate constant of 1 s-1; this rate is comparable to the rate of internal electron transfer previously determined when reducing the oxidized enzyme with azurin or cytochrome c551. When heme d1 is NO-bound, the rate at which heme c can accept electrons from ascorbate is remarkably increased as compared to the oxidized enzyme, suggesting an increase in the redox potential of the latter heme

Mother-Infant Interactions: How Mothers of Hearing-Impaired Infants Interact With Their Babies Through Touch

Since the majority of their caregivers are hearing and use spoken language, most hearing-impaired infants (HII) are faced with a different language-learning problem than their age-matched hearing (AM) peers. A hearing mismatch occurs when a caregiver and her child receive variant levels of auditory input due to their different hearing abilities. Given that HII do not treat speech as a primary mode of communication, it is possible that their caregivers may exploit non-speech modalities when interacting with their infants—similar to deaf parents of deaf infants. However, due to mismatched hearing statuses, parents of HII may have a difficulty in utilizing the modality that best corresponds with their infants’ abilities. It is imperative to understand how hearing caregivers interact with their HII in order to explore the most relevant method of communication to enhance infants’ language learning. We video- and audio-recorded play interactions between mothers of HII (4 cochlear implant users; 2 hearing aid users) and mothers of AM peers (6 hearing). Mothers were given three toys and asked to play with their child, “as they would at home.” We measured pitch, duration, and intensity in their production of the names of the toys. We also measured the number and types of touches mothers produced. Results revealed that mothers of HII and AM peers had very similar measures for pitch, duration, and intensity. However, the number and type of touches were distinct: HII were touched more than three times more frequently than AM peers. Thus, findings from this study suggest that mothers of HII may exploit non-speech modalities when they have a hearing mismatch with their child