"Roll back the years": A study of grandparent special guardians' experiences and implications for social work policy and practice in England

Growing numbers of grandparent special guardians (GSGs) are assuming responsibility for increasing numbers of children in the care system in England. Special guardianship arrangements are increasingly used as a permanency option as they allow children to remain in their kinship networks, rather than in local authority care or be adopted; yet there is a scarcity of research on GSG carers’ experiences. This article reports a small qualitative research study where ten sets of grandparents were interviewed to explore their journey to becoming GSGs and to theorise their subsequent experiences. Two themes emerge. Firstly, experiences of the assessment process are elaborated, decisions often being made at a time of family crisis, impacting on GSGs: financial, employment, relational. Secondly, GSGs’ experiences of managing often-challenging relationships and contact arrangements between the grandchildren and the parents reveal three main relationship management approaches emerging: containing-flexible; containing-controlled and; uncontained/defeated approaches. Anthropological concepts of affinity help theorise the GSGs’ ambivalent responses to becoming carers in later life, enabling reconfigured kinship relationships in new family forms. Family policy and social work practice is critiqued as GSGs appear often left alone to ‘roll back the years’, to heal previous harms done to the grandchildren who end-up in their care

Re-localisation of microscopic lesions in their macroscopic context for surgical instrument guidance

Optical biopsies interrogate microscopic structure in vivo with a 2mm diameter miniprobe placed in contact with the tissue for detection of lesions and assessment of disease progression. After detection, instruments are guided to the lesion location for a new optical interrogation, or for treatment, or for tissue excision during the same or a future examination. As the optical measurement can be considered as a point source of information at the surface of the tissue of interest, accurate guidance can be difficult. A method for re-localisation of the sampling point is, therefore, needed. The method presented in this thesis has been developed for biopsy site re-localisation during a surveillance examination of Barrett’s Oesophagus. The biopsy site, invisible macroscopically during conventional endoscopy, is re-localised in the target endoscopic image using epipolar lines derived from its locations given by the tip of the miniprobe visible in a series of reference endoscopic images. A confidence region can be drawn around the relocalised biopsy site from its uncertainty that is derived analytically. This thesis also presents a method to improve the accuracy of the epipolar lines derived for the biopsy site relocalisation using an electromagnetic tracking system. Simulations and tests on patient data identified the cases when the analytical uncertainty is a good approximation of the confidence region and showed that biopsy sites can be re-localised with accuracies better than 1mm. Studies on phantom and on porcine excised tissue demonstrated that an electromagnetic tracking system contributes to more accurate epipolar lines and re-localised biopsy sites for an endoscope displacement greater than 5mm. The re-localisation method can be applied to images acquired during different endoscopic examinations. It may also be useful for pulmonary applications. Finally, it can be combined with a Magnetic Resonance scanner which can steer cells to the biopsy site for tissue treatment

Dual Signaling System with an Extended-Tetrathiafulvalene–Phenanthroline Dyad Acting as an Electrooptical Cation Chemosensor

A tetrathiafulvalene donor has been annulated to 2,3-di(1H-2-pyrrolyl)quinoxaline affording a new chemosensor 1, which shows a unique optical selectivity and reactivity for the fluoride ion over other anions in CH2Cl2 leading to a colorimetric response. Electrochemical polymerization of 1 occurred in the presence of fluoride

Microscopic nanomechanical dissipation in gallium arsenide resonators

We report on a systematic study of nanomechanical dissipation in high-frequency (approximatively 300 MHz) gallium arsenide optomechanical disk resonators, in conditions where clamping and fluidic losses are negligible. Phonon-phonon interactions are shown to contribute with a loss background fading away at cryogenic temperatures (3 K). Atomic layer deposition of alumina at the surface modifies the quality factor of resonators, pointing towards the importance of surface dissipation. The temperature evolution is accurately fitted by two-level systems models, showing that nanomechanical dissipation in gallium arsenide resonators directly connects to their microscopic properties. Two-level systems, notably at surfaces, appear to rule the damping and fluctuations of such high-quality crystalline nanomechanical devices, at all temperatures from 3 to 300K

Internal Dust Correction Factors for Star Formation Rates Derived for Dusty \HII Regions and Starburst Galaxies

Star formation rates in galaxies are frequently estimated using the Balmer line fluxes. However, these can be systematically underestimated because dust competes for the absorption of Lyman continuum photons in the ionized gas. Here we present theoretical correction factors in a simple analytic form. T These factors scale as the product of the ionization parameter, ${\cal U}$, and the nebular O/H abundance ratio, both of which can now be derived from the observation of bright nebular line ratios. The correction factors are only somewhat dependent upon the photoelectron production by grains, but are very sensitive to the presence of complex PAH-like carbonaceous molecules in the ionized gas, providing that these can survive in such an environment.Comment: 13 pages, 1 figures, Accepted for publication in ApJ. (Feb 1, 2003

Elastic Scattering by Deterministic and Random Fractals: Self-Affinity of the Diffraction Spectrum

The diffraction spectrum of coherent waves scattered from fractal supports is calculated exactly. The fractals considered are of the class generated iteratively by successive dilations and translations, and include generalizations of the Cantor set and Sierpinski carpet as special cases. Also randomized versions of these fractals are treated. The general result is that the diffraction intensities obey a strict recursion relation, and become self-affine in the limit of large iteration number, with a self-affinity exponent related directly to the fractal dimension of the scattering object. Applications include neutron scattering, x-rays, optical diffraction, magnetic resonance imaging, electron diffraction, and He scattering, which all display the same universal scaling.Comment: 20 pages, 11 figures. Phys. Rev. E, in press. More info available at http://www.fh.huji.ac.il/~dani

Early SPI/INTEGRAL contraints on the morphology of the 511 keV line emission in the 4th galactic quadrant

We provide first constraints on the morphology of the 511 keV line emission from the galactic centre region on basis of data taken with the spectrometer SPI on the INTEGRAL gamma-ray observatory. The data suggest an azimuthally symmetric galactic bulge component with FWHM of ~9 deg with a 2 sigma uncertainty range covering 6-18 deg. The 511 keV line flux in the bulge component amounts to (9.9+4.7-2.1) 10e-4 ph cm-2 s-1. No evidence for a galactic disk component has been found so far; upper 2 sigma flux limits in the range (1.4-3.4) 10e-3 ph cm-2 s-1 have been obtained that depend on the assumed disk morphology. These limits correspond to lower limits on the bulge-to-disk ratio of 0.3-0.6.Comment: 5 pages, 3 figures, accepted for publication in A&