26,282 research outputs found
Safer recruitment practice: audit of exisiting recruitment practices in residential child care
In the wake of a number of high profile cases of the abuse of children and young people in residential child care, there have been repeated calls for the improvement of recruitment and selection of residential child care staff. Following the Children’s Safeguards Review the Scottish Executive funded the Scottish Recruitment and Selection Consortium to contribute to the safefguards for children by developing a toolkit for safer selection of staff. The toolkit was published in 2001. In 2004 the Scottish executive commisioned research form Residential Child Care (SIRCC) to identify current recruitment practices in residentialchild care for staff who have unsupervised contact with children and young people and to gauge opinion on how safer recruitment should be taken forward . A postal survey of operational and human resource managers responsible for the recruitment of residential childcare staff in local authority and voluntary organisationswas undertaken between January and April 2005. A sample of those respondents was invited to participate in semi-structured exploratory interviews, focusing in more detail on current practice and participants’ views on the implementation of the recommendations of the Toolkit
A compact spectroradiometer for solar simulator measurements
Compact spectral irradiance probe has been designed and built which uses wedge filter in conjunction with silicon cell and operational amplifier. Probe is used to monitor spectral energy distribution of solar simulators and other high intensity sources
Low Molecular Weight mRNA Encodes a Protein That Controls Serotonin 5-HT_(1c) and Acetylcholine M_1 Receptor Sensitivity in Xenopus Oocytes
Serotonin 5-HT_(1c) and acetylcholine M_1 receptors activate phosphoinositidase, resulting in an increased formation of IP_3 and 1,2 diacylglycerol. In Xenopus oocytes injected with mRNA encoding either of these receptors, Ca^(2+) released from intracellular stores in response to IP3 then opens Ca^(2+)-gated Cl^-channels. In the present experiments, oocytes expressing a transcript from a cloned mouse serotonin 5-HT_(1c) receptor were exposed to identical 15-s pulses of agonist, administered 2 min apart; the second current response was two to three times that of the first. However, in those oocytes coinjected with the 5-HT_(1c) receptor transcript and a low molecular weight fraction (0.3-1.5 kb) of rat brain mRNA, the second current response was ~50% of the first. Thus, the low molecular weight RNA encodes a protein (or proteins) that causes desensitization. Experiments using fura-2 or a Ca^(2+)-free superfusate indicated that desensitization of the 5-HT_(1c) receptor response does not result from a sustained elevation of intracellular Ca^(2+) level or require the entry of extracellular Ca^(2+). Photolysis of caged IP_3 demonstrated that an increase in IP_3 and a subsequent rise in Ca^(2+) do not produce desensitization of either the IP_3 or 5-HT_(1c) peak current responses. Furthermore, in oocytes coinjected with the low molecular weight RNA and a transcript from the rat M_1 acetylcholine receptor, the M_1 current response was greatly attenuated. Our data suggest that the proteins involved in attenuation of the M_1 current response and desensitization of the 5-HT_(1c) current response may be the same
Semicrossed Products of Operator Algebras by Semigroups
We examine the semicrossed products of a semigroup action by
-endomorphisms on a C*-algebra, or more generally of an action on an
arbitrary operator algebra by completely contractive endomorphisms. The choice
of allowable representations affects the corresponding universal algebra. We
seek quite general conditions which will allow us to show that the C*-envelope
of the semicrossed product is (a full corner of) a crossed product of an
auxiliary C*-algebra by a group action.
Our analysis concerns a case-by-case dilation theory on covariant pairs. In
the process we determine the C*-envelope for various semicrossed products of
(possibly nonselfadjoint) operator algebras by spanning cones and
lattice-ordered abelian semigroups.
In particular, we show that the C*-envelope of the semicrossed product of
C*-dynamical systems by doubly commuting representations of
(by generally non-injective endomorphisms) is the full corner of a C*-crossed
product. In consequence we connect the ideal structure of C*-covers to
properties of the actions. In particular, when the system is classical, we show
that the C*-envelope is simple if and only if the action is injective and
minimal.
The dilation methods that we use may be applied to non-abelian semigroups. We
identify the C*-envelope for actions of the free semigroup by
automorphisms in a concrete way, and for injective systems in a more abstract
manner. We also deal with C*-dynamical systems over Ore semigroups when the
appropriate covariance relation is considered.Comment: 100 pages; comments and references update
A Little of the Unusual
Two years ago this spring a rather unusual thing occurred involving three thoroughbred mares. These three mares were owned by an Indiana man and were boarded in this locality near Lexington, Ky., to be bred and foal on one particular horse farm. All three were maidens, that is, carrying their first foals, and all fairly good individuals
SpMyb functions as an intramodular repressor to regulate spatial expression of CyIIIa in sea urchin embryos
The CyIIIa actin gene of Strongylocentrotus purpuratus is
transcribed exclusively in the embryonic aboral ectoderm,
under the control of 2.3 kb cis-regulatory domain that
contains a proximal module that controls expression in
early embryogenesis, and a middle module that controls
expression in later embryogenesis. Previous studies demonstrated that the SpRunt-1 target site within the middle
module is required for the sharp increase in CyIIIa transcription which accompanies differentiation of the aboral ectoderm, and that a negative regulatory region near the SpRunt-1 target site is required to prevent ectopic transcription in the oral ectoderm and skeletogenic mesenchyme. This negative regulatory region contains a
consensus binding site for the myb family of transcription
factors. In vitro DNA-binding experiments reveal that a
protein in blastula-stage nuclei interacts specifically with
the myb target site. Gene transfer experiments utilizing
CyIIIa reporter constructs containing oligonucleotide substitutions indicate that this site is both necessary and sufficient to prevent ectopic expression of CyIIIa. Synthetic oligonucleotides containing the myb target site were used to purify a protein from sea urchin embryo nuclear extracts by affinity chromatography. This protein is immunoprecipitated by antibodies specific to the evolutionarily conserved myb domain, and amino acid sequences obtained from the purified protein were found to be identical to sequences within the myb domain. Sequence information was used to obtain cDNA clones of SpMyb, the S. purpuratus member of the myb family of transcription factors. Through interactions within the middle module, SpMyb functions to repress activation of CyIIIa in the oral
ectoderm and skeletogenic mesenchyme
Studies on Nucleic Acid Reassociation Kinetics: Retarded Rate of Hybridization of RNA with Excess DNA
The rate of reaction of excess double-stranded bacteriophage phi X174 and plasmid RSF2124 DNA drivers with enzymatically synthesized asymmetric RNA tracers was measured. Other reactions were carried out with excess Escherichia coli DNA and E. coli RNA labeled in vivo. RNA and DNA fragment lengths were held approximately equal. For each case it was shown that in DNA excess the rate constant for RNA· DNA hybridization is 3- to 4.5-fold lower than that of the renaturation rate constant for the driver DNA. This retardation was also observed in pseudo-first-order hybridization reactions driven by excess strand-separated RSF2124 DNA. It was concluded that the rate constant for RNA· DNA hybridization depends partially on which species is in excess
Regions of beta 2 and beta 4 responsible for differences between the steady state dose-response relationships of the alpha 3 beta 2 and alpha 3 beta 4 neuronal nicotinic receptors
We constructed chimeras of the rat beta 2 and beta 4 neuronal nicotinic subunits to locate the regions that contribute to differences between the acetylcholine (ACh) dose-response relationships of the alpha 3 beta 2 and alpha 3 beta 4 receptors. Expressed in Xenopus oocytes, the alpha 3 beta 2 receptor displays an EC50 for ACh approximately 20-fold less than the EC50 of the alpha 3 beta 4 receptor. The apparent Hill slope (n(app)) of alpha 3 beta 2 is near one whereas the alpha 3 beta 4 receptor displays an n(app) near two. Substitutions within the first 120 residues convert the EC50 for ACh from one wild-type value to the other. Exchanging just beta 2:104-120 for the corresponding region of beta 4 shifts the EC50 of ACh dose-response relationship in the expected direction but does not completely convert the EC50 of the dose- response relationship from one wild-type value to the other. However, substitutions in the beta 2:104-120 region do account for the relative sensitivity of the alpha 3 beta 2 receptor to cytisine, tetramethylammonium, and ACh. The expression of beta 4-like (strong) cooperativity requires an extensive region of beta 4 (beta 4:1-301). Relatively short beta 2 substitutions (beta 2:104-120) can reduce cooperativity to beta 2-like values. The results suggest that amino acids within the first 120 residues of beta 2 and the corresponding region of beta 4 contribute to an agonist binding site that bridges the alpha and beta subunits in neuronal nicotinic receptors
Unitary ambiguity in the extraction of the E2/M1 ratio for the transition
The resonant electric quadrupole amplitude in the transition is of great interest for the understanding of
baryon structure. Various dynamical models have been developed to extract it
from the corresponding photoproduction multipole of pions on nucleons. It is
shown that once such a model is specified, a whole class of unitarily
equivalent models can be constructed, all of them providing exactly the same
fit to the experimental data. However, they may predict quite different
resonant amplitudes. Therefore, the extraction of the E2/M1() ratio (bare or dressed) which is based on a dynamical
model using a largely phenomenological interaction is not unique.Comment: 10 pages revtex including 4 postscript figure
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