In it for the long haul: A reflective account of collaborative involvement in aphasia research and education

Background: The involvement of service users and supporters/advocates in healthcare education and healthcare research has developed an increasingly high profile in recent years, but relatively little is known about collaborations involving people with aphasia and family members. Aims: To reflect on and learn from the experience of collaboration, examining the ways in which the involvement of people with aphasia and family members was carried out over a fifteen-year period in the context of a UK university. Methods and procedures: We have taken a reflective longitudinal case study approach, and used constructs from implementation theory as sensitizing concepts in a cross-sectional analysis of documents in four key activities: the Conversation Partner scheme; Reaching Further Out; Supported Communication to Improve Participation in Rehabilitation; the Aphasia Research Collaboration. We then produced narrative accounts which run through the whole period of the study. Through this process, we as authors also reflected on our own experiences of collaboration. Outcomes and results: Conversation Partners (CP), integrated into the speech and language therapy practice placement, was the basis for almost all subsequent involvement. We deepened and strengthened the scope of the CP collaboration through funded workshops–Reaching Further Out–facilitated by Connect. Increasing the visibility of our collaboration enabled us to attract institutional support to develop our first major research undertaking, where people with aphasia played a key role in highlighting the need for the study, developing and implementing the intervention, taking part in project oversight, and helping disseminate the findings. The Aphasia Research Collaboration began as a partnership between speech and language therapy students and people with aphasia and has continued in various forms. Four narrative threads run through the period of this study: the importance of systems and people being adaptable; the contribution of leadership and commitment to continuity; a commitment to act and learn together; the importance of understanding value. Conclusions: Collaboration between people with aphasia, family members, and academic staff has been a collective accomplishment, where careful attention to learning, negotiation and adjustment have led to sustained involvement. In the future, where collaborations may be increasingly mediated through online technologies, all those involved must ensure that these are supported by robust and inclusive processes

Peripheral hearing loss at age 70 predicts brain atrophy and associated cognitive change

BACKGROUND: Hearing loss has been proposed as a modifiable risk factor for dementia. However, the relationship between hearing, neurodegeneration, and cognitive change, and the extent to which pathological processes such as Alzheimer's disease and cerebrovascular disease influence these relationships, is unclear. METHODS: Data from 287 adults born in the same week of 1946 who underwent baseline pure tone audiometry (mean age=70.6 years) and two time point cognitive assessment/multimodal brain imaging (mean interval 2.4 years) were analysed. Hearing impairment at baseline was defined as a pure tone average of greater than 25 decibels in the best hearing ear. Rates of change for whole brain, hippocampal and ventricle volume were estimated from structural MRI using the Boundary Shift Integral. Cognition was assessed using the Pre-clinical Alzheimer's Cognitive Composite. Regression models were performed to evaluate how baseline hearing impairment associated with subsequent brain atrophy and cognitive decline after adjustment for a range of confounders including baseline β-amyloid deposition and white matter hyperintensity volume. RESULTS: 111 out of 287 participants had hearing impairment. Compared with those with preserved hearing, hearing impaired individuals had faster rates of whole brain atrophy, and worse hearing (higher pure tone average) predicted faster rates of hippocampal atrophy. In participants with hearing impairment, faster rates of whole brain atrophy predicted greater cognitive change. All observed relationships were independent of β-amyloid deposition and white matter hyperintensity volume. CONCLUSIONS: Hearing loss may influence dementia risk via pathways distinct from those typically implicated in Alzheimer's and cerebrovascular disease in cognitively unimpaired older adults

Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 75 (2011): 5247-5268, doi:10.1016/j.gca.2011.06.026.We present whole rock Li and Mg isotope analyses of 33 ultramafic xenoliths from the terrestrial mantle, which we compare with analyses of 30 (mostly chondritic) meteorites. The accuracy of our new Mg isotope ratio measurement protocol is substantiated by a combination of standard addition experiments, the absence of mass independent effects in terrestrial samples and our obtaining identical values for rock standards using 2 different separation chemistries and 3 different mass-spectrometric introduction systems. Carbonaceous, ordinary and enstatite chondrites have irresolvable mean stable Mg isotopic compositions (δ25Mg = -0.14 ± 0.06; δ26Mg = - 0.27 ± 0.12‰, 2sd), but our enstatite chondrite samples have lighter δ7Li (by up to ~3‰) than our mean carbonaceous and ordinary chondrites (3.0 ± 1.5‰, 2sd), possibly as a result of spallation in the early solar system. Measurements of equilibrated, fertile peridotites give mean values of δ7Li = 3.5 ± 0.5‰, δ25Mg = -0.10 ± 0.03‰ and δ26Mg = -0.21 ± 0.07‰. We believe these values provide a useful estimate of the primitive mantle and they are within error of our average of bulk carbonaceous and ordinary chondrites. A fuller range of fresh, terrestrial, ultramafic samples, covering a variety of geological histories, show a broad positive correlation between bulk δ7Li and δ26Mg, which vary from -3.7 to +14.5‰, and -0.36 to +0.06‰, respectively. Values of δ7Li and δ26Mg lower than our estimate of primitive mantle are strongly linked to kinetic isotope fractionation, occurring during transport of the mantle xenoliths. We suggest Mg and Li diffusion into the xenoliths is coupled to H loss from nominally anhydrous minerals following degassing. Diffusion models suggest that the co-variation of Mg and Li isotopes requires comparable diffusivities of Li and Mg in olivine. The isotopically lightest samples require ~5-10 years of diffusive ingress, which we interpret as a time since volatile loss in the host magma. Xenoliths erupted in pyroclastic flows appear to have retained their mantle isotope ratios, likely as a result of little prior degassing in these explosive events. High δ7Li, coupled with high [Li], in rapidly cooled arc peridotites may indicate that these samples represent fragments of mantle wedge that has been metasomatised by heavy, slab-derived fluids. If such material is typically stirred back into the convecting mantle, it may account for the heavy δ7Li seen in some oceanic basalts.PPvS was supported by NERC grant NER/C510983/

Los actos intrínsecamente malos y la enseñanza de la encíclica «Veritatis Splendor»

We have assessed the reliability of several foraminifer-hosted proxies of the ocean carbonate system (δ 11B, B/Ca, and U/Ca) using Holocene samples from the Atlantic and Pacific oceans. We examined chemical variability over a range of test sizes for two surface-dwelling foraminifers (Globigerinoides sacculifer and Globigerinoides ruber). Measurements of δ 11B in G. ruber show no significant relationship with test size in either Atlantic or Pacific sites and appear to provide a robust proxy of surface seawater pH. Likewise there is no significant variability in the δ 11B of our Atlantic core top G. sacculifer, but we find that δ 11B increases with increasing test size for G. sacculifer in the Pacific. These systematic differences in δ 11B are inferred to be a consequence of isotopically light gametogenic calcite in G. sacculifer and its preferential preservation during postdepositional dissolution. The trace element ratio proxies of ocean carbonate equilibria, U/Ca and B/Ca, show systematic increases in both G. ruber and G. sacculifer with increasing test size, possibly as a result of changing growth rates. This behavior complicates their use in paleoceanographic reconstructions. In keeping with several previous studies we find that Mg/Ca ratios increase with increasing size fraction in our well-preserved Atlantic G. sacculifer but not in G. ruber. In contrast to previous interpretations we suggest that these observations reflect a proportionally larger influence of compositionally distinct gametogenic calcite in small individuals compared to larger ones. As with δ 11B this influences G. sacculifer but not G. ruber, which has negligible gametogenic calcite

Iron isotope fractionation by chemotrophic iron-oxidisers

Knowledge of the isotopic behaviour of iron in natural and experimental systems has expanded considerably since initial work began in this field However, a greater understanding of the pathways and controls on Fe isotopic fractionation, produced from the abiological and biological transformations of Fe, is still needed to characterise the global Fe biogeochemical cycle in a manner comparable to that of the carbon isotope system. Oxidation and reduction of Fe by direct or indirect microbial activity plays a large role in the global cycling of Fe. The discovery of chemotrophic microorganisms able to oxidise Fe anaerobically increases the importance of Fe recycling via redox reactions in natural environments, as well as extending the diversity of Fe-utilising microbial metabolisms. Fe isotopic fractionation by strains of the chemolithotrophic bacterium Thiobacillus denitrificans, has been investigated. Batch experiments have been done using different inoculum potentials, temperatures, and pO2 levels with Fe(II) as the only electron donor. Iron isotope compositions were determined by high-resolution, multiple collector, ICP-MS, with an external precision (1 s) on d56Fe and d57Fe of ± 0.05 and 0.08 ‰, respectively. The analytical methods were similar to those in the literature [3]. Preliminary data shows a – 0.8 ‰ d56Fe Fe isotopic fractionation between Fe(II) in solution and FeOOH precipitate. This isotopic shift between substrate and product can be attributed to biological oxidation as no abiotic Fe oxidation occurred in concomitant sterile controls. Experiments examining variable pO2 levels in both abiotic and biological systems provide a useful basis to examine how the isotopic signature of biological oxidation is modified by abiotic Fe oxidation

Solution and laser ablation MC-ICP-MS lead isotope analysis of gold

A new approach is presented for the analysis of lead isotopes in gold using solution and laser ablation multi-collector inductively-coupled plasma mass-spectrometry (MC-ICP-MS). Repeat analyses of two gold reference materials (RAuGP3: 34.1 +/- 0.5 ppm Pb and RAuGP5: 129 +/- 4 ppm Pb, from SPEX CertiPrep Ltd) yield an external reproducibility of 20. Instrumental mass bias is corrected by standard sample bracketing, using NIST SRM981 for solution analyses and NIST SRM610 for laser ablation analyses. Both techniques agree within error, and they have been further demonstrated through the analyses of both geological and archaeological samples: multiple grains from two Irish alluvial gold deposits and samples of two Early Bronze Age Irish gold lunulae. The applicability of these techniques to studies concerning the sources and age of gold mineralisation, and the identification of gold sources exploited in antiquity, is highlighted.</p

Solution and laser ablation MC-ICP-MS lead isotope analysis of gold

A new approach is presented for the analysis of lead isotopes in gold using solution and laser ablation multi-collector inductively-coupled plasma mass-spectrometry (MC-ICP-MS). Repeat analyses of two gold reference materials (RAuGP3: 34.1 ± 0.5 ppm Pb and RAuGP5: 129 ± 4 ppm Pb, from SPEX CertiPrep Ltd) yield an external reproducibility of &lt;150 ppm for 207Pb/206Pb and 208Pb/206Pb and &lt;250 ppm for 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb for solution analyses after lead separation using a two-stage ion exchange chromatography methodology. External reproducibility of &lt;600 ppm for 207Pb/206Pb and 208Pb/206Pb is achieved for laser ablation analyses. Due to the low abundance of 204Pb and the isobaric interference of mercury, the external reproducibility for 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb is strongly dependant on the 204(Pb + Hg)/202Hg ratio: &lt;1640 ppm when 204(Pb + Hg)/202Hg [similar]1 to 5, &lt;900 ppm when 204(Pb + Hg)/202Hg [similar]5 to 20, and &lt;810 ppm when 204(Pb + Hg)/202Hg &gt;20. Instrumental mass bias is corrected by standard sample bracketing, using NIST SRM981 for solution analyses and NIST SRM610 for laser ablation analyses. Both techniques agree within error, and they have been further demonstrated through the analyses of both geological and archaeological samples: multiple grains from two Irish alluvial gold deposits and samples of two Early Bronze Age Irish gold lunulae. The applicability of these techniques to studies concerning the sources and age of gold mineralisation, and the identification of gold sources exploited in antiquity, is highlighte

In situ ion microprobe ²⁰⁷Pb/²⁰⁶Pb dating of monazite from Precambrian metamorphic suites, Tobacco Root Mountains, Montana

The Precambrian rocks of the Tobacco Root Mountains have been separated into three suites: the Indian Creek Metamorphic Suite, the Pony-Middle Mountain Metamorphic Suite, and the Spuhler Peak Metamorphic Suite. The Indian Creek and Pony-Middle Mountain Metamorphic Suites are quartzofeldspathic gneiss suites that contain variable amounts of metasupracrustal rocks. The Spuhler Peak Metamorphic Suite contains primarily mafic rocks and is possibly ocean crust. Metamorphosed mafic dikes and sills that intruded the Indian Creek and Pony-Middle Mountain Meta morphic Suites, but not the Spuhler Peak Metamorphic Suite, indicate juxtaposition of the Spuhler Peak Metamorphic Suite with the other two suites after intrusion of the dikes at ca. 2060 Ma. All rocks have been deformed and metamorphosed together, initially at pressures greater than 1.0 GPa and temperatures greater than 750 °C, followed by differential reequilibration at ∼0.6 GPa on a clockwise pressure-temperature path. Two-hundred-seventy-two 207Pb/206Pb spot ages of monazite grains from seventeen Spuhler Peak Metamorphic Suite, five Pony-Middle Mountain Metamorphic Suite, and eight Indian Creek Metamorphic Suite rocks have been obtained from the University of California at Los Angeles ion microprobe. Based on the distribution of the ages, the samples can be divided into three groups. (1) All seventeen Spuhler Peak Metamorphic Suite, one Pony-Middle Mountain Metamorphic Suite, and two Indian Creek Metamorphic Suite samples have relatively homogeneous spot age populations that vary from ca. 1720 to ca. 1780 Ma. (2) A group of seven Indian Creek and Pony-Middle Mountain Metamorphic Suite samples has spot ages from monazite grains that form an array near 2450 Ma. (3) A group of four Indian Creek and Pony-Middle Mountain Metamorphic Suite samples are bimodal in that they contain spot ages from both the 1720-1780 Ma group and the 2450 Ma array. There are younger and a few older spot ages in these samples that likely represent mixed age domains, the former between the 1720-1780 Ma and the 2450 Ma age domains and the latter between older detrital grain cores and the 2450 Ma array. Monazite grains in the matrix have similar ages to those that occur as inclusions in garnet and kyanite. Thus, the monazite in these rocks, as well as the peak metamorphic minerals, either grew or re-equilibrated during the higher-pressure (>1.0 GPa) metamorphism. The near absence of 207Pb/206Pb ages older than 1780 Ma in the Spuhler Peak Metamorphic Suite and the common occurrence of older ages in monazite from the Indian Creek and Pony-Middle Mountain Metamorphic Suites are consistent with assembly of the Tobacco Root terrane during a prolonged (60 m.y. long) collision event, the Big Sky orogeny, beginning at ca. 1780 Ma and culminating at ca. 1720 Ma. The Early Proterozoic Big Sky orogeny significantly overprinted the effects of an earlier ca. 2450 Ma orogeny in both the Pony-Middle Mountain and Indian Creek Metamorphic Suites. This older event modified pre-existing Archean rocks. However, of the 272 spot ages on monazite grains reported here, only six are significantly older than 2450 Ma and only one of these is older than 2600 Ma - a 2988 Ma spot age from a monazite inclusion in a garnet from a Pony-Middle Mountain Metamorphic Suite sample. There is no evidence of widespread Archean events recorded in the monazite grains of the Tobacco Root Mountains. © 2004 Geological Society of America.Link_to_subscribed_fulltex