2,036 research outputs found
Canada’s Bitumen Industry Under CO2 Constraints
Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).We investigate the effects of implementing CO2 emissions reduction policies on Canada’s oil sands industry, the largest of its kind in the world. The production of petroleum products from oils sands involves extraction of bitumen from the oil sands, upgrading it to a synthetic crude oil by adding lighter hydrocarbons, and then use of more conventional petroleum refining processes to create products such as gasoline and diesel. The relatively heavy crude generally requires the use of cracking and other advanced refinery operations to generate a product slate with substantial fractions of the higher value petroleum products such as diesel and gasoline. Each part of the process involves significant amounts of energy, and that contributes to a high level of CO2 emissions. We apply the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium model of the world economy, augmented to include detail on the oil sands production processes, including the possibility of carbon capture and storage (CCS). We find: (1) without climate policy annual Canadian bitumen production increases over 6-fold from 2005 to 2050; (2) with CO2 emissions caps implemented in developed countries, Canadian bitumen production drops by nearly 65% from the reference 6-fold increase and bitumen upgrading capacity moves to the developing countries; (3) with CO2 emissions caps implemented worldwide, the Canadian bitumen production becomes essentially non-viable even with CCS technology, at least through our 2050 horizon. The main reason for the demise of the oil sands industry with global CO2 policy is that the demand for oil worldwide drops substantially. CCS takes care of emissions from the oil sands production, upgrading, and refining processes, at a cost, but there is so little demand for petroleum products which still emit CO2 when used that it can be met with conventional oil resources that entail less CO2 emissions in the production process.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors
Treatment differences by health insurance among outpatients with coronary artery disease
OBJECTIVES: To compare treatment rates by insurance status for 5 quality-of-care indicators for coronary artery disease (CAD) care related to medication treatment. METHOD: Within the NCDR's PINNACLE Registry, we identified 60,814 outpatients with CAD from 30 U.S. practices. Hierarchical modified Poisson regression models with practice site as a random effect were used to study the association between health insurance (no insurance, public or private health insurance) and 5 CAD quality measures. RESULTS: Of 60,814 patients, 5716 (9.4%) patients were uninsured and 11,962 (19.7%) had public insurance, whereas 43,136 (70.9%) were privately insured. After accounting for exclusions, uninsured patients with CAD were 9%, 12%, and 6% less likely to receive treatment with beta-blocker, ACE-I/ARB, and lipid lowering therapy, respectively, than privately insured patients, whereas patients with public insurance were 9% less likely to be prescribed ACE-I/ARB therapy. Most differences by insurance status were attenuated after adjusting for the site providing care. For example, whereas uninsured patients with left ventricular dysfunction and CAD were less likely to receive ACE-I/ARB therapy (unadjusted RR=0.88; 95% CI 0.84-0.93), this difference was eliminated after adjustment for site (adjusted RR=0.95; 95% CI 0.88-1.03; P=0.18). CONCLUSIONS: Within this national outpatient cardiac registry, uninsured patients were less likely to receive evidence-based medications for CAD. These disparities were explained by the site providing care. Efforts to reduce treatment differences by insurance status among cardiac outpatients may additionally need to focus on improving rates of evidence-based treatment at sites with high proportions of uninsured patients
Bone CLARITY: Clearing, imaging, and computational analysis of osteoprogenitors within intact bone marrow
Bone tissue harbors unique and essential physiological processes, such as hematopoiesis, bone growth, and bone remodeling. To enable visualization of these processes at the cellular level in an intact environment, we developed “Bone CLARITY,” a bone tissue clearing method. We used Bone CLARITY and a custom-built light-sheet fluorescence microscope to detect the endogenous fluorescence of Sox9-tdTomato+ osteoprogenitor cells in the tibia, femur, and vertebral column of adult transgenic mice. To obtain a complete distribution map of these osteoprogenitor cells, we developed a computational pipeline that semiautomatically detects individual Sox9-tdTomato+ cells in their native three-dimensional environment. Our computational method counted all labeled osteoprogenitor cells without relying on sampling techniques and displayed increased precision when compared with traditional stereology techniques for estimating the total number of these rare cells. We demonstrate the value of the clearing-imaging pipeline by quantifying changes in the population of Sox9-tdTomato–labeled osteoprogenitor cells after sclerostin antibody treatment. Bone tissue clearing is able to provide fast and comprehensive visualization of biological processes in intact bone tissue
52-week efficacy and safety of telbivudine with conditional tenofovir intensification at week 24 in HBeAg-positive chronic Hepatitis B
Background and Aims: The Roadmap concept is a therapeutic framework in chronic hepatitis B for the intensification of nucleoside analogue monotherapy based on early virologic response. The efficacy and safety of this approach applied to telbivudine treatment has not been investigated.
Methods: A multinational, phase IV, single-arm open-label study (ClinicalTrials.gov ID NCT00651209) was undertaken in HBeAg-positive, nucleoside-naive adult patients with chronic hepatitis B. Patients received telbivudine (600 mg once-daily) for 24 weeks, after which those with undetectable serum HBV DNA (<300 copies/mL) continued to receive telbivudine alone while those with detectable DNA received telbivudine plus tenofovir (300 mg once-daily). Outcomes were assessed at Week 52.
Results: 105 patients commenced telbivudine monotherapy, of whom 100 were included in the efficacy analysis. Fifty-five (55%) had undetectable HBV DNA at Week 24 and continued telbivudine monotherapy; 45 (45%) received tenofovir intensification. At Week 52, the overall proportion of undetectable HBV DNA was 93% (93/100) by last-observation-carried-forward analysis (100% monotherapy group, 84% intensification group) and no virologic breakthroughs had occurred. ALT normalization occurred in 77% (87% monotherapy, 64% intensification), HBeAg clearance in 43% (65% monotherapy, 16% intensification), and HBeAg seroconversion in 39% (62% monotherapy, 11% intensification). Six patients had HBsAg clearance. Myalgia was more common in the monotherapy group (19% versus 7%). No decrease in the mean glomerular filtration rate occurred in either treatment group at Week 52.
Conclusions: Telbivudine therapy with tenofovir intensification at Week 24, where indicated by the Roadmap strategy, appears effective and well tolerated for the treatment of chronic hepatitis B.
Trial Registration: ClinicalTrials.gov NCT0065120
A bayesian meta-analysis of multiple treatment comparisons of systemic regimens for advanced pancreatic cancer
© 2014 Chan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: For advanced pancreatic cancer, many regimens have been compared with gemcitabine (G) as the standard arm in randomized controlled trials. Few regimens have been directly compared with each other in randomized controlled trials and the relative efficacy and safety among them remains unclear
Antibody stabilization for thermally accelerated deep immunostaining
Antibodies have diverse applications due to their high reaction specificities but are sensitive to denaturation when a higher working temperature is required. We have developed a simple, highly scalable and generalizable chemical approach for stabilizing off-the-shelf antibodies against thermal and chemical denaturation. We demonstrate that the stabilized antibodies (termed SPEARs) can withstand up to 4 weeks of continuous heating at 55 °C and harsh denaturants, and apply our method to 33 tested antibodies. SPEARs enable flexible applications of thermocycling and denaturants to dynamically modulate their binding kinetics, reaction equilibrium, macromolecular diffusivity and aggregation propensity. In particular, we show that SPEARs permit the use of a thermally facilitated three-dimensional immunolabeling strategy (termed ThICK staining), achieving whole mouse brain immunolabeling within 72 h, as well as nearly fourfold deeper penetration with threefold less antibodies in human brain tissue. With faster deep-tissue immunolabeling and broad compatibility with tissue processing and clearing methods without the need for any specialized equipment, we anticipate the wide applicability of ThICK staining with SPEARs for deep immunostaining
A Randomized Double-Blind Crossover Study of Phase-Shift Sound Therapy for Tinnitus
Objective. The purpose of this study was to compare the efficacy of the treatment of tinnitus with a phase-shifting pure tone to that of the same tone treatment without phase shifting. Study Design. A double-blind crossover randomized controlled trial. Setting. This study was conducted at the University Medical Center Groningen. Subjects and Methods. Twenty-two patients with predominantly tonal tinnitus underwent both intervention and control treatments. Each treatment consisted of three 30-minute sessions in 1 week. The control treatment was identical to the intervention treatment, except that the stimulus was a pure tone without phase shifting. Questionnaires, tinnitus loudness match, and annoyance and loudness ratings were used to measure treatment effects. Results. Pure-tone treatment and phase-shift treatment had no significant effect on tinnitus according to questionnaires (Tinnitus Handicap Index, Tinnitus Reaction Questionnaire, Hospital Anxiety and Depression Scale, and Maastricht Questionnaire), audiological matching procedures, and loudness and annoyance ratings of tinnitus. Furthermore, phase-shift treatment showed no additional significant improvement in comparison with pure-tone treatment. Changes in questionnaire scores due to pure-tone and the phase-shift treatment were correlated. Conclusion. On average across the group, both treatments failed to demonstrate a significant effect. Both treatments were beneficial for some patients. However, a positive effect was not demonstrated that could be attributed to the periodic shifting of the phase of the stimulus tone
Prenatal muscle development in a mouse model for the secondary dystroglycanopathies
The defective glycosylation of α-dystroglycan is associated with a group of muscular dystrophies that are collectively referred to as the secondary dystroglycanopathies. Mutations in the gene encoding fukutin-related protein (FKRP) are one of the most common causes of secondary dystroglycanopathy in the UK and are associated with a wide spectrum of disease. Whilst central nervous system involvement has a prenatal onset, no studies have addressed prenatal muscle development in any of the mouse models for this group of diseases. In view of the pivotal role of α-dystroglycan in early basement membrane formation, we sought to determine if the muscle formation was altered in a mouse model of FKRP-related dystrophy
Inhibitory role of peroxisome proliferator-activated receptor gamma in hepatocarcinogenesis in mice and in vitro
Although peroxisome proliferator-activated receptor gamma (PPARγ) agonist have been shown to inhibit hepatocellular carcinoma (HCC) development, the role of PPARγ in hepatocarcinogenesis remains unclear. We investigated the therapeutic efficacy of PPAR
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