An effective energy technology strategy has to balance between setting a stable long term framework for innovation, while also responding to more immediate changes in technology cost and performance. ...Over the last decade, rather than a steady progression along an established learning curve, PV costs and prices have been volatile, with increases or plateaus followed by rapid reductions. The paper describes, and considers the causes of, recent changes in PV costs and prices at module and system level, both international trends and more place-specific contexts. It finds that both module and system costs and price trends have reflected multiple overlapping forces. Established forecasting methods – experience curves and engineering assessments – have limited ability to capture key learning effects behind recent PV cost and price trends: production scale effects, industrial re-organization and shakeouts, international trade practices and national market dynamics. These forces are likely to remain prominent aspect of technology learning effects in the foreseeable future – and so are in need of improved, more explicit representation in energy technology forecasting.
Decarbonisation goals have triggered photovoltaic (PV) sector expansion and cost reductions in PV technologies. Thin film (TF) PV technologies are currently the cheapest to manufacture and offer the ...possibility of attaining lower costs. However, scarcity of key component materials has been highlighted as a potential barrier to both large scale deployment and reductions in technology cost. This paper explores this claim for cadmium telluride (CdTe) and copper indium gallium (di)selenide (CIGS) TF technologies and their potentially constraining materials, tellurium and indium. It reviews key literature, highlighting the high uncertainty in the estimates of the resource constrained TF PV potential as well as in data and methodologies used to assess future availability of the targeted materials. The reviewed evidence does not support the contention that the availability of tellurium and indium will necessarily constrain CdTe and CIGS technologies respectively in their ability to supply expected future PV market growth. However, future escalation in indium and tellurium price resulting from demand–supply imbalances could have a negative impact on CdTe and CIGS cost reduction ambitions. Factors influencing indium and tellurium price and their relative contribution to TF PV module production cost need further investigation.
Summary
Objective
We evaluated the efficacy and safety of deep brain anterior thalamus stimulation after 7 and 10 years, and report the incidence of sudden unexpected death in epilepsy (SUDEP) and ...overall mortality in adults in the Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy (SANTÉ) study.
Methods
After the 3‐month blinded and 9‐month unblinded phases, subjects continued to be assessed during long‐term follow‐up (LTFU) and later a continued therapy access phase (CAP), to further characterize adverse events and the incidence of SUDEP. Stimulus parameter and medication changes were allowed.
Results
One hundred ten implanted subjects accumulated a total of 938 device‐years of experience (69 subjects during the LTFU phase and 61 subjects in the CAP phase). Prior to study closure, 57 active subjects continued therapy at 14 study centers, with follow‐up of at least 10 (maximum 14) years. At 7 years, median seizure frequency percent reduction from baseline was 75% (p < .001), with no outcome differences related to prior vagus nerve stimulation or resective surgery. The most severe seizure type, focal to bilateral tonic–clonic, was reduced by 71%. Adding new antiseizure medications did not impact the pattern of seizure reduction over time. There were no unanticipated serious adverse events in the study. The definite‐plus‐probable SUDEP rate, based on SANTÉ study experience (two deaths in 938 years) and previous pilot studies (0 deaths in 76 years), indicated a rate of 2.0 deaths for 1000 person‐years. Overall mortality was 6.9 deaths per 1000 person‐years.
Significance
The long‐term efficacy and safety profiles of the deep brain stimulation (DBS) system for epilepsy are favorable and demonstrate stable outcomes. Improvement in frequency of the most severe seizure type may reduce SUDEP risk. The SUDEP rate with DBS (2.0) is comparable to other neuromodulation treatments (i.e., vagus nerve stimulation, responsive neurostimulation) for drug‐resistant focal epilepsy.
Electric vehicles using lithium batteries could significantly reduce the emissions associated with road vehicle transport. However, the future availability of lithium is uncertain, and the ...feasibility of manufacturing lithium batteries at sufficient scale has been questioned. The levels of lithium demand growth implied by electric vehicle deployment scenarios is significant, particularly where scenarios are consistent with global GHG reduction targets. This paper examines the question of future lithium availability for the manufacturing of lithium batteries for electric vehicles.
In this paper we first examine some of the existing literature in this area, highlighting the levels of future lithium demand previously considered and pointing to the variables that give rise to the range of outcomes in these assessments. We then investigate the ways in which lithium availability is calculated in the literature based on both lithium demand from electric vehicles and lithium supply from both brines and ore.
This paper particularly focuses on the key variables needed to make an assessment of future lithium availability. On the demand side, these variables include future market size of electric vehicles, their average battery capacity and the material intensity of the batteries. The key supply variables include global reserve and resource estimates, forecast production and recyclability.
We found that the literature informing assumptions regarding the key variables is characterised by significant uncertainty. This uncertainty gives rise to a wide range of estimates for the future demand for lithium based on scenarios consistent with as 50% reduction in global emissions by 2050 at between 184,000 and 989,000t of lithium per year in 2050. However, lithium production is forecast to grow to between 75,000 and 110,000t per year by 2020. Under this rate of production growth, it is plausible that lithium supply will meet increasing lithium demand over the coming decades to 2050.
Public vs. Private Gross, Robert N
2017, 2018-03-01, 2018, 2017-12-01
eBook
Americans today choose from a dizzying array of schools, loosely lumped into categories of “public” and “private.” How did these distinctions emerge in the first place, and what do they tell us about ...the more general relationship in the United States between public authority and private enterprise? Public vs. Private describes how nineteenth-century public policies fostered the rise of modern school choice. In the late nineteenth century, American Catholics began constructing rival, urban parochial school systems, an enormous and dramatic undertaking that challenged public school systems’ near-monopoly of education. In a nation deeply committed to public education, mass attendance in Catholic private schools produced immense conflict. States quickly sought ways to regulate this burgeoning private sector and the competition it produced, even attempting to abolish private education altogether in the 1920s. Ultimately, however, Public vs. Private shows how the public policies that resulted produced a stable educational marketplace, where school choice flourished. The creation of systematic alternatives to public schools was as much a product of public power as of private initiative. As ever more policies today seek to unleash market forces in education, Public vs. Private concludes that Americans would do well to learn from the historical relationship between government, markets, and schools.
OBJECTIVE:To report long-term efficacy and safety results of the SANTE trial investigating deep brain stimulation of the anterior nucleus of the thalamus (ANT) for treatment of localization-related ...epilepsy.
METHODS:This long-term follow-up is a continuation of a previously reported trial of 5- vs 0-V ANT stimulation. Long-term follow-up began 13 months after device implantation with stimulation parameters adjusted at the investigatorsʼ discretion. Seizure frequency was determined using daily seizure diaries.
RESULTS:The median percent seizure reduction from baseline at 1 year was 41%, and 69% at 5 years. The responder rate (≥50% reduction in seizure frequency) at 1 year was 43%, and 68% at 5 years. In the 5 years of follow-up, 16% of subjects were seizure-free for at least 6 months. There were no reported unanticipated adverse device effects or symptomatic intracranial hemorrhages. The Liverpool Seizure Severity Scale and 31-item Quality of Life in Epilepsy measure showed statistically significant improvement over baseline by 1 year and at 5 years (p < 0.001).
CONCLUSION:Long-term follow-up of ANT deep brain stimulation showed sustained efficacy and safety in a treatment-resistant population.
CLASSIFICATION OF EVIDENCE:This long-term follow-up provides Class IV evidence that for patients with drug-resistant partial epilepsy, anterior thalamic stimulation is associated with a 69% reduction in seizure frequency and a 34% serious device-related adverse event rate at 5 years.
The functional neuroanatomy of dystonia Neychev, Vladimir K; Gross, Robert E; Lehéricy, Stephane ...
Neurobiology of disease,
05/2011, Letnik:
42, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Abstract Dystonia is a neurological disorder characterized by involuntary twisting movements and postures. There are many different clinical manifestations, and many different causes. The ...neuroanatomical substrates for dystonia are only partly understood. Although the traditional view localizes dystonia to basal ganglia circuits, there is increasing recognition that this view is inadequate for accommodating a substantial portion of available clinical and experimental evidence. A model in which several brain regions play a role in a network better accommodates the evidence. This network model accommodates neuropathological and neuroimaging evidence that dystonia may be associated with abnormalities in multiple different brain regions. It also accommodates animal studies showing that dystonic movements arise with manipulations of different brain regions. It is consistent with neurophysiological evidence suggesting defects in neural inhibitory processes, sensorimotor integration, and maladaptive plasticity. Finally, it may explain neurosurgical experience showing that targeting the basal ganglia is effective only for certain subpopulations of dystonia. Most importantly, the network model provides many new and testable hypotheses with direct relevance for new treatment strategies that go beyond the basal ganglia. This article is part of a Special Issue entitled “Advances in dystonia”.
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