28,700 research outputs found
Recommended from our members
Consultation and consequences: A view on the services experienced by some young people and six families
Reports the views of some young people and 6 families on services received from social care professionals. Summarises the main themes that emerged and emphasises the issue of professional reliability as articulated in these 2 small, but in depth, studies. The views of both sets of interviewees contributed to the creation of a course for front line managers drawing from user and worker consultations. Draws on the interviews to shed light on various aspects of professional relationships with services users and what they said they wanted. Discussion sets this in the context of policy agenda
Video Evidence That London Infants Can Resettle Themselves Back to Sleep After Waking in the Night, as well as Sleep for Long Periods, by 3 Months of Age
Objective: Most infants become settled at night by 3 months of age, whereas infants not settled by 5 months are likely to have long-term sleep-waking problems. We assessed whether normal infant development in the first 3 months involves increasing sleep-period length or the ability to resettle autonomously after waking in the night. Methods: One hundred one infants were assessed at 5 weeks and 3 months of age using nighttime infrared video recordings and parental questionnaires. Results: The clearest development was in sleep length; 45% of infants slept continuously for 5 hours or more at night at 3 months compared with 10% at 5 weeks. In addition, around a quarter of infants woke and resettled themselves back to sleep in the night at each age. Autonomous resettling at 5 weeks predicted prolonged sleeping at 3 months suggesting it may be a developmental precursor. Infants reported by parents to sleep for a period of 5 hours or more included infants who resettled themselves and those with long sleeps. Three-month olds fed solely breast milk were as likely to self-resettle or have long sleep bouts as infants fed formula or mixed breast and formula milk. Conclusions: Infants are capable of resettling themselves back to sleep in the first 3 months of age; both autonomous resettling and prolonged sleeping are involved in “sleeping through the night” at an early age. Findings indicate the need for physiological studies of how arousal, waking, and resettling develop into sustained sleeping and of how environmental factors support these endogenous and behavioral processes
Barium and heavy metals in the waters and aquatic plants of the catchment of Bleaberry Gill, North Yorkshire
Ca, Zn, Ba and Pb concentrations were measured in the waters and plants of Bleaberry Gill, North Yorkshire. Ba concentrations were compared with those of other streams in Arkengarthdale, considered to be non-contaminated by mining activity. Ba concentrations in bryophytes from Bleaberry Gill were an order of magnitude greater than those from streams uncontaminated with Ba, though aqueous concentrations were only 2-3 X greater. Zn was not present in particularly elevated concentrations, though Pb concentrations were elevated. Concentrations of these elements in bryophytes were not particularly high compared to other mining areas. In a series of experiments Hygrohypnum ochraceum was transplanted between streams with different aqueous metal concentrations. Uptake of Ba was rapid in populations of moss previously exposed to low and medium concentrations of Ba in water. The population from the lower Ba site achieved a lower maximum concentration than the population from the medium Ba site. Loss of Ba was rapid after a short exposure to elevated concentrations but took longer after prolonged exposure. The behaviour of Zn was similar, though both uptake and loss were slower than for Ba. Possible effects of proposed mining developments in the catchment of Bleaberry Gill are considered
Turbulence characteristics of the B\"{o}dewadt layer in a large enclosed rotor-stator system
A three-dimensional (3D) direct numerical simulation is combined with a
laboratory study to describe the turbulent flow in an enclosed annular
rotor-stator cavity characterized by a large aspect ratio G=(b-a)/h=18.32 and a
small radius ratio a/b=0.152, where a and b are the inner and outer radii of
the rotating disk and h is the interdisk spacing. The rotation rate Omega under
consideration is equivalent to the rotational Reynolds number Re=Omegab2/nu=9.5
x 104, where nu is the kinematic viscosity of the fluid. This corresponds to a
value at which an experiment carried out at the laboratory has shown that the
stator boundary layer is turbulent, whereas the rotor boundary layer is still
laminar. Comparisons of the 3D computed solution with velocity measurements
have given good agreement for the mean and turbulent fields. The results
enhance evidence of weak turbulence at this Reynolds number, by comparing the
turbulence properties with available data in the literature. An approximately
self-similar boundary layer behavior is observed along the stator side. The
reduction of the structural parameter a1 under the typical value 0.15 and the
variation in the wall-normal direction of the different characteristic angles
show that this boundary layer is three-dimensional. A quadrant analysis of
conditionally averaged velocities is performed to identify the contributions of
different events (ejections and sweeps) on the Reynolds shear stress producing
vortical structures. The asymmetries observed in the conditionally averaged
quadrant analysis are dominated by Reynolds stress-producing events in this
B\"{o}dewadt layer. Moreover, case 1 vortices (with a positive wall induced
velocity) are found to be the major source of generation of special strong
events, in agreement with the conclusions of Lygren and Andersson.Comment: 16 page
Radio and X-ray properties of submillimeter galaxies in the A2125 field
We present the radio and X-ray properties of 1.2 mm MAMBO source candidates
in a 1600 sq. arcmin field centered on the Abell 2125 galaxy cluster at
z=0.247. The brightest, non-synchrotron mm source candidate in the field has a
photometric redshift, z = 3.93^+1.11_-0.80, and is not detected in a 31 ks
Chandra X-ray exposure. These findings are consistent with this object being an
extremely dusty and luminous starburst galaxy at high-redshift, possibly the
most luminous yet identified in any blank-field mm survey. The deep 1.4 GHz VLA
imaging identifies counterparts for 83% of the 29 mm source candidates
identified at >=4-sigma S(1.2mm) = 2.7 - 52.1 mJy, implying that the majority
of these objects are likely to lie at z <~ 3.5. The median mm-to-radio
wavelength photometric redshift of this radio-detected sample is z~2.2 (first
and third quartiles of 1.7 and 3.0), consistent with the median redshift
derived from optical spectroscopic surveys of the radio-detected subsample of
bright submm galaxies (S(850um) > 5 mJy). Three mm-selected quasars are
confirmed to be X-ray luminous in the high resolution Chandra imaging, while
another mm source candidate with potential multiple radio counterparts is also
detected in the X-ray regime. Both of these radio counterparts are positionally
consistent with the mm source candidate. One counterpart is associated with an
elliptical galaxy at z = 0.2425, but we believe that a second counterpart
associated with a fainter optical source likely gives rise to the mm emission
at z~1.Comment: Accepted for publication in Ap
An X-ray and Optical Investigation of the Environments Around Nearby Radio Galaxies
Investigations of the cluster environment of radio sources have not shown a
correlation between radio power and degree of clustering. However, it has been
demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a
positive correlation. This study investigates a complete sample of 25 nearby (z
less than 0.06) radio galaxies which are not cataloged members of Abell
clusters. The environment of these radio galaxies is studied in both the X-ray
and the optical by means of the ROSAT All-Sky Survey (RASS), ROSAT pointed
observations, and the Palomar optical Digitized Sky Survey (DSS). X-ray
luminosities and extents are determined from the RASS, and the DSS is used to
quantify the degree of clustering via the spatial two-point correlation
coefficient, Bgg. Of the 25 sources, 20 are greater than sigma detections in
the X-ray and 11 possessed Bgg's significantly in excess of that expected for
an isolated galaxy. Adding the criterion that the X-ray emission be resolved,
10 of the radio galaxies do appear to reside in poor clusters with extended
X-ray emission suggestive of the presence of an intracluster medium. Eight of
these galaxies also possess high spatial correlation coefficients. Taken
together, these data suggest that the radio galaxies reside in a low richness
extension of the Abell clusters. The unresolved X-ray emission from the other
galaxies is most likely associated with AGN phenomena. Furthermore, although
the sample size is small, it appears that the environments of FR I and FR II
sources differ. FR I's tend to be more frequently associated with extended
X-ray emission (10 of 18), whereas FR II's are typically point sources or
non-detections in the X-ray (none of the 7 sources exhibit extended X-ray
emission).Comment: 28 page postscript file including figures and tables, plus one
landscape table and 5 GIF figure
Cognitive performance in multiple system atrophy
The cognitive performance of a group of patients with multiple system atrophy (MSA) of striato-nigral predominance was compared with that of age and IQ matched control subjects, using three tests sensitive to frontal lobe dysfunction and a battery sensitive to memory and learning deficits in Parkinson's disease and dementia of the Alzheimer type. The MSA group showed significant deficits in all three of the tests previously shown to be sensitive to frontal lobe dysfunction. Thus, a significant proportion of patients from the MSA group failed an attentional set-shifting test, specifically at the stage when an extra-dimensional shift was required. They were also impaired in a subject-ordered test of spatial working memory. The MSA group showed deficits mostly confined to measures of speed of thinking, rather than accuracy, on the Tower of London task. These deficits were seen in the absence of consistent impairments in language or visual perception. Moreover, the MSA group showed no significant deficits in tests of spatial and pattern recognition previously shown to be sensitive to patients early in the course of probable Alzheimer's disease and only a few patients exhibited impairment on the Warrington Recognition Memory Test. There were impairments on other tests of visual memory and learning relative to matched controls, but these could not easily be related to fundamental deficits of memory or learning. Thus, on a matching-to-sample task the patients were impaired at simultaneous but not delayed matching to sample, whereas difficulties in a pattern-location learning task were more evident at its initial, easier stages. The MSA group showed no consistent evidence of intellectual deterioration as assessed from their performance on subtests of the Wechsler Adult Intelligence Scale (WAIS) and the National Adult Reading Test (NART). Consideration of individual cases showed that there was some heterogeneity in the pattern of deficits in the MSA group, with one patient showing no impairment, even in the face of considerable physical disability. The results show a distinctive pattern of cognitive deficits, unlike those previously seen using the same tests in patients with Parkinson's and Alzheimer's diseases, and suggesting a prominent frontal-lobe-like component. The implications for concepts of 'subcortical' dementia and 'fronto-striatal' cognitive dysfunction are considered
- …