1,767 research outputs found
Building user commitment to implementing a knowledge management strategy
In the IS literature, commitment is typically considered to involve organizational or managerial support for a system and not that of its users. This paper however reports on a field study involving 16 organizations that attempted to build user involvement in developing a knowledge management strategy by having them design it. Twenty-two IT-supported group workshops (involving 183 users) were run to develop action plans for better knowledge management that users would like to see implemented. Each workshop adopted the same problem structuring technique to assist group members develop a politically feasible action plan to which they were psychologically and emotionally dedicated. In addition to reviewing the problem structuring method, this paper provides qualitative insight into the factors a knowledge management strategy should have to encourage user commitment. © 2004 Elsevier B.V. All rights reserved
Green operations strategy of a luxury car manufacturer
This paper investigates the strategic environmental decisions of a luxury car manufacturer. Through case study research, the investigation sheds light on why and how the company is adopting green technologies. Being pressured by different stakeholders to become greener, luxury car manufacturers carry significant opportunities for environmental improvement given the nature of their manufacturing processes and products. Because of their low-volume production, manufacturers may be able to increase output and still reduce overall emissions when compared to high-volume manufacturers. In the case study company this was found to be possible only because of new ideas brought by a change in ownership. Luxury manufacturers may also be a test-bed for the development and experimentation of green technologies as part of a strategic approach to environmental initiatives. This paper contributes to the fields of green technology adoption and operations strategy in automotive manufacturing groups
Nicoya Peninsula, Costa Rica: A single suite of Caribbean oceanic plateau magmas
The pre‐Tertiary oceanic crust exposed on the west coast of Costa Rica has been broadly referred to as the Nicoya Complex. This study was designed to determine the age of the Nicoya Complex in the Nicoya Peninsula, Playa Jacó, and the Quepos Peninsula using 40Ar‐39Ar radiometric dating and to assess the petrologic relationships between the different localities using major element, trace element, and Sr, Nd, Pb isotopic data. Radiometric ages of basalts and diabases from the Nicoya Peninsula are 88–90 Ma (with a weighted mean of 88.5 Ma), and those of two intrusive rocks (a gabbro and plagiogranite) are both 83–84 Ma. The combined geochemical data indicate that the sampled Nicoya Peninsula rocks belong to a single suite related by fractional crystallization of similar parental magmas. Nd and Pb isotopic ratios indicate a common mantle source distinct from that of mid‐ocean ridge basalts. Both the age and composition of the Nicoya rocks are consistent with the idea that they are a part of the Caribbean Cretaceous oceanic plateau [Donnelly, 1994]. The Jacó lavas are geochemically similar to the Nicoya Peninsula suite, and a single age of 84 Ma is identical to the age of the Nicoya Peninsula intrusives. The one analyzed Quepos basalt has a radiometric age of ∼64 Ma, and it is enriched in incompatible elements relative to the Nicoya rocks. Similarities in Nd and Pb isotopic ratios indicate that the Quepos and Nicoya/Jacó lavas were derived from a similar mantle source to that which produced the Nicoya rocks, possibly the Galapagos plume
Multi-wavelength study of a new Galactic SNR G332.5-5.6
We present compelling evidence for confirmation of a Galactic supernova
remnant (SNR) candidate, G332.5-5.6, based initially on identification of new,
filamentary, optical emission line nebulosity seen in the arcsecond resolution
images from the AAO/UKST HAlpha survey. The extant radio observations and X-ray
data which we have independently re-reduced, together with new optical
spectroscopy of the large-scale fragmented nebulosity, confirms the
identification. Optical spectra, taken across five different, widely separated
nebula regions of the remnant as seen on the HAlpha images, show average ratios
of [NII]/HAlpha =2.42, [SII]/HAlpha = 2.10, and [SII] 6717/6731 = 1.23, as well
as strong [OI] 6300, 6364A and [OII] 3727A emission. These ratios are firmly
within those typical of SNRs. Here, we also present the radio-continuum
detection of the SNR at 20/13cm from observations with the Australia Telescope
Compact Array (ATCA). Radio emission is also seen at 4850 MHz, in the PMN
survey (Griffith and Wright 1993) and at 843 MHz from the SUMSS survey (Bock,
Large and Sadler 1999). We estimate an angular diameter of ~30 arcmin and
obtain an average radio spectral index of alpha = -0.6 +- 0.1 which indicates
the non-thermal nature of G332.5-5.6. Fresh analysis of existing ROSAT X-ray
data in the vicinity also confirms the existence of the SNR. The distance to
G332.5-5.6 has been independently estimated by Reynoso and Green (2007) as 3.4
kpc based on measurements of the HI lambda21 cm line seen in absorption against
the continuum emission. Our cruder estimates via assumptions on the height of
the dust layer (3.1 kpc) and using the Sigma-D relation (4 kpc) are in good
agreement.Comment: 14 pages, 18 figures. Accepted for publishing in the MNRA
Repetitive arm functional tasks after stroke (RAFTAS): a pilot randomised controlled trial
Background
Repetitive functional task practise (RFTP) is a promising treatment to improve upper limb recovery following stroke. We report the findings of a study to determine the feasibility of a multi-centre randomised controlled trial to evaluate this intervention.
Methods
A pilot randomised controlled trial was conducted. Patients with new reduced upper limb function were recruited within 14 days of acute stroke from three stroke units in North East England. Participants were randomised to receive a four week upper limb RFTP therapy programme consisting of goal setting, independent activity practise, and twice weekly therapy reviews in addition to usual post stroke rehabilitation, or usual post stroke rehabilitation. The recruitment rate; adherence to the RFTP therapy programme; usual post stroke rehabilitation received; attrition rate; data quality; success of outcome assessor blinding; adverse events; and the views of study participants and therapists about the intervention were recorded.
Results
Fifty five eligible patients were identified, 4-6% of patients screened at each site. Twenty four patients participated in the pilot study. Two of the three study sites met the recruitment target of 1-2 participants per month. The median number of face to face therapy sessions received was 6 [IQR 3-8]. The median number of daily repetitions of activities recorded was 80 [IQR 39-80]. Data about usual post stroke rehabilitation were available for 18/24 (75%). Outcome data were available for 22/24 (92%) at one month and 20/24 (83%) at three months. Outcome assessors were unblinded to participant group allocation for 11/22 (50%) at one month and 6/20 (30%) at three months. Four adverse events were considered serious as they resulted in hospitalisation. None were related to study treatment. Feedback from patients and local NHS therapists about the RFTP programme was mainly positive.
Conclusions
A multi-centre randomised controlled trial to evaluate an upper limb RFTP therapy programme provided early after stroke is feasible and acceptable to patients and therapists, but there are issues which needed to be addressed when designing a Phase III study. A Phase III study will need to monitor and report not only recruitment and attrition but also adherence to the intervention, usual post stroke rehabilitation received, and outcome assessor blinding
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A feasibility randomised controlled trial of a motivational interviewing-based intervention for weight loss maintenance in adults
Background
Obesity has significant health and NHS cost implications. Relatively small reductions in weight have clinically important benefits, but long-term weight loss maintenance (WLM) is challenging. Behaviour change interventions have been identified as key for WLM. Motivation is crucial to supporting behaviour change, and motivational interviewing (MI) has been identified as a successful approach to changing health behaviours. The study was designed as an adequately powered, pragmatic randomised controlled trial (RCT); however, owing to recruitment issues, the study became a feasibility trial.
Objectives
To assess recruitment, retention, feasibility, acceptability, compliance and delivery of a 12-month intervention to support WLM. Secondary objectives were to assess the impact of the intervention on body mass index (BMI) and other secondary outcomes.
Design
Three-arm individually randomised controlled trial comprising an intensive arm, a less intensive arm and a control arm.
Setting
Community setting in South Wales and the East Midlands.
Participants
Individuals aged 18�70 years with a current or previous BMI of ??30 kg/m2 who could provide evidence of at least 5% weight loss during the previous 12 months.
Intervention
Participants received individually tailored MI, which included planning and self-monitoring. The intensive arm received six face-to-face sessions followed by nine telephone sessions. The less intensive arm received two face-to-face sessions followed by two telephone sessions. The control arm received a leaflet advising them on healthy lifestyle.
Main outcome measures
Feasibility outcomes included numbers recruited, retention and adherence. The primary effectiveness outcome was BMI at 12 months post randomisation. Secondary outcomes included waist circumference, waist-to-hip ratio, physical activity, proportion maintaining weight loss, diet, quality of life, health service resource usage, binge eating and well-being. A process evaluation assessed intervention delivery, adherence, and participants� and practitioners� views. Economic analysis aimed to assess cost-effectiveness in terms of quality-adjusted life-years (QALYs).
Results
A total of 170 participants were randomised. Retention was good (84%) and adherence was excellent (intensive, 83%; less intensive, 91%). The between-group difference in mean BMI indicated the intensive arm had BMIs 1.0?kg/m2 lower than the controls [95% confidence interval (CI) �2.2 kg/m2 to 0.2?kg/m2]. Similarly, a potential difference was found in weight (average difference of 2.8?kg, 95% CI �6.1 kg to 0.5?kg). The intensive arm had odds of maintaining on average 43% [odds ratio(OR) 1.4, 95% CI 0.6 to 3.5] higher than controls. None of these findings were statistically significant. Further analyses controlling for level of adherence indicated that average BMI was 1.2?kg/m2 lower in the intensive arm than the control arm (95% CI �2.5?kg/m2 to 0.0?kg/m2). The intensive intervention led to a statistically significant difference in weight (mean �3.7?kg, 95% CI �7.1?kg to �0.3?kg). The other secondary outcomes showed limited evidence of differences between groups. The intervention was delivered as planned, and both practitioners and participants were positive about the intervention and its impact. Although not powered to assess cost-effectiveness, results of this feasibility study suggest that neither intervention as currently delivered is likely to be cost-effective in routine practice.
Conclusion
This is the first trial of an intervention for WLM in the UK, the intervention is feasible and acceptable, and retention and adherence were high. The main effectiveness outcome showed a promising mean difference in the intensive arm. Owing to the small sample size, we are limited in the conclusions we can draw. However, findings suggest that the intensive intervention may facilitate long-term weight maintenance and, therefore, further testing in an effectiveness trial may be indicated. Research examining WLM is in its infancy, further research is needed to develop our understanding of WLM and to expand theory to inform the development of interventions to be tested in rigorously designed RCTs with cost-effectiveness assessed
Trace element cycling in a subterranean estuary : part 2. Geochemistry of the pore water
Author Posting. © The Authors, 2005. 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 70 (2006): 811-826, doi:10.1016/j.gca.2005.10.019.Submarine groundwater discharge (SGD) is an important source of dissolved elements to
the ocean, yet little is known regarding the chemical reactions that control their flux from sandy
coastal aquifers. The net flux of elements from SGD to the coastal ocean is dependent on
biogeochemical reactions in the groundwater-seawater mixing zone, recently termed the
"subterranean estuary". This paper is the second in a two part series on the biogeochemistry of
the Waquoit Bay coastal aquifer/subterranean estuary. The first paper addressed the
biogeochemistry of Fe, Mn, P, Ba, U, and Th from the perspective of the sediment composition
of cores (Charette et al., 2005). This paper uses pore water data from the subterranean estuary,
along with Bay surface water data, to establish a more detailed view into the estuarine chemistry
and the chemical diagenesis of Fe, Mn, U, Ba and Sr in coastal aquifers.
Nine high-resolution pore water (groundwater) profiles were collected from the head of
the bay during July 2002. There were non-conservative additions of both Ba and Sr in the
salinity transition zone of the subterranean estuary. However, the extent of Sr release was
significantly less than that of its alkaline earth neighbor Ba. Pore water Ba concentrations
approached 3000 nM compared with 25-50 nM in the surface waters of the bay; the pore water
Sr-salinity distribution suggests a 26% elevation in the amount of Sr added to the subterranean
estuary. The release of dissolved Ba to the mixing zone of surface estuaries is frequently
attributed to an ion-exchange process whereby seawater cations react with Ba from river
suspended clay mineral particles at low to intermediate salinity. Results presented here suggest
that reductive dissolution of Mn oxides, in conjunction with changes in salinity, may also be an
important process in maintaining high concentrations of Ba in the pore water of subterranean
estuaries.
In contrast, pore water U was significantly depleted in the subterranean estuary, a result
of SGD-driven circulation of seawater through reducing permeable sediments. This finding is
supported by surface water concentrations of U in the bay, which were significantly depleted in
U compared with adjacent coastal waters. Using a global estimate of SGD, we calculate U
removal in subterranean estuaries at 20 x 106 mol U y-1, which is the same order of magnitude as
the other major U sinks for the ocean. Our results suggest a need to revisit and reevaluate the
oceanic budgets for elements that are likely influenced by SGD-associated processes.This research was supported by the National Science Foundation (OCE-0095384) to M.A.C. and
E.R.S., and a WHOI Coastal Ocean Institute Fellowship to M.A.C
GABAergic cortical network physiology in frontotemporal lobar degeneration.
The clinical syndromes caused by frontotemporal lobar degeneration are heterogeneous, including the behavioural variant frontotemporal dementia (bvFTD) and progressive supranuclear palsy. Although pathologically distinct, they share many behavioural, cognitive and physiological features, which may in part arise from common deficits of major neurotransmitters such as γ-aminobutyric acid (GABA). Here, we quantify the GABAergic impairment and its restoration with dynamic causal modelling of a double-blind placebo-controlled crossover pharmaco-magnetoencephalography study. We analysed 17 patients with bvFTD, 15 patients with progressive supranuclear palsy, and 20 healthy age- and gender-matched controls. In addition to neuropsychological assessment and structural MRI, participants undertook two magnetoencephalography sessions using a roving auditory oddball paradigm: once on placebo and once on 10 mg of the oral GABA reuptake inhibitor tiagabine. A subgroup underwent ultrahigh-field magnetic resonance spectroscopy measurement of GABA concentration, which was reduced among patients. We identified deficits in frontotemporal processing using conductance-based biophysical models of local and global neuronal networks. The clinical relevance of this physiological deficit is indicated by the correlation between top-down connectivity from frontal to temporal cortex and clinical measures of cognitive and behavioural change. A critical validation of the biophysical modelling approach was evidence from parametric empirical Bayes analysis that GABA levels in patients, measured by spectroscopy, were related to posterior estimates of patients' GABAergic synaptic connectivity. Further evidence for the role of GABA in frontotemporal lobar degeneration came from confirmation that the effects of tiagabine on local circuits depended not only on participant group, but also on individual baseline GABA levels. Specifically, the phasic inhibition of deep cortico-cortical pyramidal neurons following tiagabine, but not placebo, was a function of GABA concentration. The study provides proof-of-concept for the potential of dynamic causal modelling to elucidate mechanisms of human neurodegenerative disease, and explains the variation in response to candidate therapies among patients. The laminar- and neurotransmitter-specific features of the modelling framework, can be used to study other treatment approaches and disorders. In the context of frontotemporal lobar degeneration, we suggest that neurophysiological restoration in selected patients, by targeting neurotransmitter deficits, could be used to bridge between clinical and preclinical models of disease, and inform the personalized selection of drugs and stratification of patients for future clinical trials
Neurophysiological consequences of synapse loss in progressive supranuclear palsy
Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even in the absence of gross atrophy. Currently, for human disease there are few formal models to explain how cortical networks underlying cognition are affected by synaptic loss. We advocate that biophysical models of neurophysiology offer both a bridge from clinical to preclinical models of pathology, and quantitative assays for experimental medicine. Such biophysical models can also disclose hidden neuronal dynamics generating neurophysiological observations like electro- and magneto-encephalography. Here, we augment a biophysically informed mesoscale model of human cortical function by inclusion of synaptic density estimates as captured by [11C]UCB-J positron emission tomography, and provide insights into how regional synapse loss affects neurophysiology. We use the primary tauopathy of progressive supranuclear palsy (Richardson's syndrome) as an exemplar condition, with high clinicopathological correlations. Progressive supranuclear palsy causes a marked change in cortical neurophysiology in the presence of mild cortical atrophy and is associated with a decline in cognitive functions associated with the frontal lobe. Using parametric empirical Bayesian inversion of a conductance-based canonical microcircuit model of magnetoencephalography data, we show that the inclusion of regional synaptic density-as a subject-specific prior on laminar specific neuronal populations-markedly increases model evidence. Specifically, model comparison suggests that a reduction in synaptic density in inferior frontal cortex affects superficial and granular layer glutamatergic excitation. This predicted individual differences in behaviour, demonstrating the link between synaptic loss, neurophysiology, and cognitive deficits. The method we demonstrate is not restricted to progressive supranuclear palsy or the effects of synaptic loss: such pathology-enriched dynamic causal models can be used to assess the mechanisms of other neurological disorders, with diverse non-invasive measures of pathology, and is suitable to test the effects of experimental pharmacology
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