138 research outputs found
Induced innovation and international environmental agreements: evidence from the ozone regime
This paper revisits one of the rare success stories in global environmental cooperation: the Montreal Protocol and the phase-out of ozone-depleting substances. I show that the protocol increased science and innovation on alternatives to ozone-depleting substances and argue that agreements can indeed be useful to solving global public goods problems. This contrasts with game-theoretical predictions that agreements occur only when costs to the players are low, and with the often-heard narrative that substitutes were readily available. I reconcile theory and empirics by discussing the role of induced innovation in models of environmental agreements
Induced innovation and international environmental agreements: evidence from the Ozone regime
Global environmental problems are some of the most pressing issues that humanity is facing. There are few examples of success at resolving them; the fight to protect the ozone layer is one of them. This paper provides evidence that the Montreal Protocolâs restrictions on chlorofluorocarbons ( CFCs) triggered a substantial increase in research and innovation on alternatives to ozone-depleting molecules. I compare CFC substitute molecules to molecules that have similar uses but are unrelated to ozone depletion. After the signing of the agreement, patents on CFC substitutes increased by 400% and scientific articles by 500% compared to the control group. These findings suggest that agreements can indeed trigger the development of technological solutions, thereby improving the benefit-cost equation of environmental protectio
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Essays on the Economics of Technological Change and the Environment
Technological change bears the promise of addressing environmental problems without reneging on economic development. However, taping its full potential requires an understanding of its drivers and barriers. The three chapters of this dissertation are a modest attempt at casting light on some of the factors that can foster technological change towards more environmental-friendly technologies. In Chapter One, I provide the first quantitative evidence that the Montreal Protocol, and its following amendments to protect the ozone layer, triggered a large increase in research and innovation on alternatives to ozone-depleting molecules. To do this, I use the full text of patents and scientific articles and implement a difference-in-differences strategy and a synthetic control method. To compare moleculesâ chemical and industrial characteristics, I construct descriptive variables by applying machine learning techniques to the documentsâ text. In Chapter Two, I investigate barriers to adopting solar lanterns in the context of rural Indian households. I design and implement a randomized controlled trial on peopleâs willingness to pay for such lanterns, and find that, despite the relative simplicity of the product, information barriers to adopting solar lanterns remain high. Chapter Three theoretically investigates firm-level barriers to green technological change. I outline a mechanism that explains why coordination at the industry level might be necessary. I argue that radical innovations (such as electric cars) require complementary innovations in interdependent components, and show that, when technological change requires investment by both suppliers and producers, coordination within an industry is needed and can be difficult to obtain
Induced innovation, inventors and the energy transition
We study how individual inventors respond to incentives to work on 'clean' electricity technologies. Using natural gas price variation, we estimate output and entry elasticities of inventors and measure the medium-term impacts of a price increase mirroring the social cost of carbon. We find that the induced clean innovation response primarily comes from existing clean inventors. New inventors are less responsive on the margin than their average contribution to clean energy patenting would indicate. Our findings suggest a role for policy to increase the supply of clean inventors to help mitigate climate change
Directed technological change and general purpose technologies: can AI accelerate clean energy innovation?
Transitioning away from dirty and towards clean technologies is critical to reduce carbon emissions, but the race between clean and dirty technologies is taking place against the backdrop of improvements in general-purpose technologies (GPT) such as information and communication technologies (ICT) and artificial intelligence (AI). We show how, in theory, a GPT can affect the direction of technological change and, in particular, the competition between clean and dirty technologies. Second, we use patent data to show that clean technologies absorb more spillovers from AI and ICT than dirty technologies and that energy patenting firms with higher AI knowledge stocks are more likely to absorb AI spillovers for their energy inventions. We conclude that ICT and AI have the potential to accelerate clean energy innovation
Traditional Chinese medicines in the treatment of hepatocellular cancers: a systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>Liver cancer is a common malignancy with a high mortality rate. Given the poor prognosis associated with this cancer, many patients seek additional therapies that may improve quality of life or survival. Several Traditional Chinese Medicines (TCM) have been evaluated in clinical trials, but little is known about them outside of China.</p> <p>Methods</p> <p>We searched independently and in duplicate 8 electronic databases, including 2 Chinese language databases, until February 2009. We included any randomized clinical trials (RCT) evaluating a TCM oral preparation for the treatment of hepatocellular cancers. We abstracted data on survival, tumor response, and performance scores. We conducted a random-effects meta-analysis and applied a meta-regression analysis.</p> <p>Results</p> <p>We included 45 RCTs (n = 3,236). All studies employed an active control group. In general, the reporting of methodological issues was poor. We analyzed data from 37 trials reporting on complete response effects score (Relative Risk [RR] of 1.26 (95 CI, 1.04â1.52, P = 0.01, I<sup>2 </sup>= 0%, P = 0.99). Products containing ginseng, astragalus and mylabris had a larger treatment effect (OR 1.34, 95% CI, 1.04â1.71, P = 0.01) than the pooled broad estimate, also the case for astragalus-based treatments (OR 1.35, 95% CI, 1.001â1.80. P = 0.048). We examined survival rates and pooled 15 studies reporting on 6 month outcomes (RR 1.10, 95% CI, 1.04â1.15, P = < 0.0001, I<sup>2 </sup>= 0%, P = 0.60). This effect was consistent at other prospective dates, including 12 months (22 trials, RR 1.26, 95% CI, 1.17â1.36, P = < 0.0001, I<sup>2 </sup>= 7%, P = 0.36), 24 months (15 trials, 1.72, 95% CI, 1.40â2.03, P = < 0.0001, I<sup>2 </sup>= 0%, P = 0.75); and, at 36 months (8 trials, RR 2.40, 95% CI, 1.65â3.49, P = < 0.0001, I<sup>2 </sup>= 0%, P = 0.62).</p> <p>Limitations</p> <p>All included trials were conducted in China where emerging evidence suggests many RCTs are not, in fact, randomized. Publication bias may exist, favouring positive reports.</p> <p>Conclusion</p> <p>Our meta-analysis displays compelling evidence of effectiveness for hepatocellular cancers that should be evaluated in high-quality and transparent clinical trials.</p
P02.123. The anti-diabetic and cholesterol-lowering effects of common and cassia cinnamon (Cinnamomum verum and C. aromaticum): a randomized controlled trial
This paper accompanies a poster presentation on the anti-diabetic and cholesterol-lowering effects of common and cassia cinnamon (Cinnamomum verum and C. aromaticum)
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A systematic review of non-antibiotic measures for the prevention of urinary tract infections in pregnancy
Background:
Urinary tract infections (UTIs) are common in pregnancy and account for the highest proportion of primary care antibiotic prescriptions issued to pregnant women in the UK. It is well known that antibiotic use is associated with increased antimicrobial resistance and therefore measures to minimise antibiotic use for UTI prevention have been studied. The efficacy and safety of these measures in pregnancy have not been addressed and therefore the aim of this study was to systematically review the literature to identify and evaluate potential measures to prevent UTIs in pregnant women.
Methods:
Ten databases (EMBASE, AMED, BNI, CINAHL, Medline, PubMed, PsycINFO, Cochrane Trials, Scopus and Science Direct) were systematically searched in July 2017 for studies reporting non-antibiotic measures to prevent UTIs in pregnancy. The terms (âurinary tract infectionâor UTI or bacteriuria or cystitis) AND (prevention) AND (pregnan*) were used. The quality of the publications was appraised using the Critical Appraisal Skills Programme (CASP) checklists for cohort study, case-control study and randomised controlled trial. The results were synthesised using a textual
narrative approach.
Results:
Search results yielded 3276 publications and after reviewing titles and removing duplicates, 57 full text articles were assessed for eligibility and eight were included in the review. Five different approaches (hygiene measures, cranberry juice, immunisation, ascorbic acid and CanephronÂź N) have been identified, all of which are reported to be safe in pregnancy.
Conclusion:
The quality of the evidence varied considerably and only hygiene measures were supported by evidence to be recommended in practice. Future work needs to concentrate on strengthening the evidence base through improved design and reporting of studies with a focus on immunisation, ascorbic acid and CanephronÂź N
'Asking the right question'. A comparison of two approaches to gathering data on 'herbals' use in survey based studies
BACKGROUND:Over the last decade academic interest in the prevalence and nature of herbal medicines use by pregnant women has increased significantly. Such data are usually collected by means of an administered questionnaire survey, however a key methodological limitation using this approach is the need to clearly define the scope of 'herbals' to be investigated. The majority of published studies in this area neither define 'herbals' nor provide a detailed checklist naming specific 'herbals' and CAM modalities, which limits inter-study comparison, generalisability and the potential for meta-analyses. The aim of this study was to compare the self-reported use of herbs, herbal medicines and herbal products using two different approaches implemented in succession. METHODS:Cross-sectional questionnaire surveys of women attending for their mid-trimester scan or attending the postnatal unit following live birth at the Royal Aberdeen Maternity Hospital, North-East Scotland. The questionnaire utilised two approaches to collect data on 'herbals' use, a single closed yes/no answer to the question "have you used herbs, herbal medicines and herbal products in the last three months"; and a request to tick which of a list of 40 'herbals' they had used in the same time period. RESULTS:A total of 889 responses were obtained of which 4.3% (38) answered 'yes' to herbal use via the closed question. However, using the checklist 39% (350) of respondents reported the use of one or more specific 'herbals' (p<0.0001). The 312 respondents who reported 'no' to 'herbals' use via the closed question but "yes" via the checklist consumed a total of 20 different 'herbals' (median 1, interquartile range 1-2, range 1-6). CONCLUSIONS:This study demonstrates that the use of a single closed question asking about the use of 'herbals', as frequently reported in published studies, may not yield valid data resulting in a gross underestimation of actual use
Ginkgo biloba for the treatment of vitilgo vulgaris: an open label pilot clinical trial
<p>Abstract</p> <p>Background</p> <p>Vitiligo is a common hypopigmentation disorder with significant psychological impact if occurring before adulthood. A pilot clinical trial to determine the feasibility of an RCT was conducted and is reported here.</p> <p>Methods</p> <p>12 participants 12 to 35 years old were recruited to a prospective open-label pilot trial and treated with 60 mg of standardized <it>G. biloba </it>two times per day for 12 weeks. The criteria for feasibility included successful recruitment, 75% or greater retention, effectiveness and lack of serious adverse reactions. Effectiveness was assessed using the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force (VETF), which are validated outcome measures evaluating the area and intensity of depigmentation of vitiligo lesions. Other outcomes included photographs and adverse reactions. Safety was assessed by serum coagulation factors (platelets, PTT, INR) at baseline and week 12.</p> <p>Results</p> <p>After 2 months of recruitment, the eligible upper age limit was raised from 18 to 35 years of age in order to facilitate recruitment of the required sample size. Eleven participants completed the trial with 85% or greater adherence to the protocol. The total VASI score improved by 0.5 (P = 0.021) from 5.0 to 4.5, range of scale 0 (no depigmentation) to 100 (completely depigmented). The progression of vitiligo stopped in all participants; the total VASI indicated an average repigmentation of vitiligo lesions of 15%. VETF total vitiligo lesion area decreased 0.4% (P = 0.102) from 5.9 to 5.6 from baseline to week 12. VETF staging score improved by 0.7 (P = 0.101) from 6.6 to 5.8, and the VETF spreading score improved by 3.9 (P < 0.001)) from 2.7 to -1.2. There were no statistically significant changes in platelet count, PTT, or INR.</p> <p>Conclusions</p> <p>The criteria for feasibility were met after increasing the maximum age limit of the successful recruitment criterion; participant retention, safety and effectiveness criteria were also met. Ingestion of 60 mg of <it>Ginkgo biloba </it>BID was associated with a significant improvement in total VASI vitiligo measures and VETF spread, and a trend towards improvement on VETF measures of vitiligo lesion area and staging. Larger, randomized double-blind clinical studies are warranted and appear feasible.</p> <p>Trial Registration</p> <p>Clinical trials.gov registration number <a href="http://www.clinicaltrials.gov/ct2/show/NCT00907062">NCT00907062</a></p
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