We analyze the effect of fuel mix, model specification, and the level of development on the presence and size of a turning point in the relationship between income and energy use and/or carbon ...emissions. The results indicate that fuel mix, the specification for income, and the level of economic development affect conclusions about whether there is a turning point in the relationship between economic activity and energy use and carbon emissions. Including fuel shares generally reduces the size of a turning point that is estimated from a panel that includes observations from both OECD and Non-OECD nations. But this result varies according to the level of development. For OECD nations, there is limited support for a turning point in the relationship between income and per capita energy use and/or carbon emissions. For non-OECD nations, there is no turning point in the relationship between income and either energy use or carbon emissions. Instead, the relationship is positive. Together, the results indicate that forecasters and policy makers should not depend on a turning point in the relationship between income and energy use or carbon emissions to reduce either.
China has experienced rapid urbanization and dramatic economic growth since its reform process started in late 1978. In this article, we present evidence for a significant urbanization effect on ...climate based on analysis of impacts of land-use changes on surface temperature in southeast China, where rapid urbanization has occurred. Our estimated warming of mean surface temperature of 0.05°C per decade attributable to urbanization is much larger than previous estimates for other periods and locations. The spatial pattern and magnitude of our estimate are consistent with those or urbanization characterized by changes in the percentage of urban population and in satellite-measured greenness.
The isolation of cell-free DNA (cfDNA) from the bloodstream can be used to detect and analyze somatic alterations in circulating tumor DNA (ctDNA), and multiple cfDNA-targeted sequencing panels are ...now commercially available for Food and Drug Administration (FDA)-approved biomarker indications to guide treatment. More recently, cfDNA fragmentation patterns have emerged as a tool to infer epigenomic and transcriptomic information. However, most of these analyses used whole-genome sequencing, which is insufficient to identify FDA-approved biomarker indications in a cost-effective manner.
We used machine learning models of fragmentation patterns at the first coding exon in standard targeted cancer gene cfDNA sequencing panels to distinguish between cancer and non-cancer patients, as well as the specific tumor type and subtype. We assessed this approach in two independent cohorts: a published cohort from GRAIL (breast, lung, and prostate cancers, non-cancer, n = 198) and an institutional cohort from the University of Wisconsin (UW; breast, lung, prostate, bladder cancers, n = 320). Each cohort was split 70%/30% into training and validation sets.
In the UW cohort, training cross-validated accuracy was 82.1%, and accuracy in the independent validation cohort was 86.6% despite a median ctDNA fraction of only 0.06. In the GRAIL cohort, to assess how this approach performs in very low ctDNA fractions, training and independent validation were split based on ctDNA fraction. Training cross-validated accuracy was 80.6%, and accuracy in the independent validation cohort was 76.3%. In the validation cohort where the ctDNA fractions were all <0.05 and as low as 0.0003, the cancer versus non-cancer area under the curve was 0.99.
To our knowledge, this is the first study to demonstrate that sequencing from targeted cfDNA panels can be utilized to analyze fragmentation patterns to classify cancer types, dramatically expanding the potential capabilities of existing clinically used panels at minimal additional cost.
The terrestrial carbon sink, as of yet unidentified, represents 15-30% of annual global emissions of carbon from fossil fuels and industrial activities. Some of the missing carbon is sequestered in ...vegetation biomass and, under the Kyoto Protocol of the United Nations Framework Convention on Climate Change, industrialized nations can use certain forest biomass sinks to meet their greenhouse gas emissions reduction commitments. Therefore, we analyzed 19 years of data from remote-sensing spacecraft and forest inventories to identify the size and location of such sinks. The results, which cover the years 1981-1999, reveal a picture of biomass carbon gains in Eurasian boreal and North American temperate forests and losses in some Canadian boreal forests. For the 1.42 billion hectares of Northern forests, roughly above the 30th parallel, we estimate the biomass sink to be 0.68 ± 0.34 billion tons carbon per year, of which nearly 70% is in Eurasia, in proportion to its forest area and in disproportion to its biomass carbon pool. The relatively high spatial resolution of these estimates permits direct validation with ground data and contributes to a monitoring program of forest biomass sinks under the Kyoto protocol.
The Pearl River Delta in the People's Republic of China is experiencing rapid rates of economic growth. Government directives in the late 1970s and early 1980s spurred economic development that has ...led to widespread land conversion. In this study, we monitor land-use through a nested hierarchy of land-cover. Change vectors of Tasseled Cap brightness, greenness and wetness of Landsat Thematic Mapper (TM) images are combined with the brightness, greenness, wetness values from the initial date of imagery to map four stable classes and five changes classes. Most of the land-use change is conversion from agricultural land to urban areas. Results indicate that urban areas have increased by more than 300% between 1988 and 1996. Field assessments confirm a high overall accuracy of the land-use change map (93.5%) and support the use of change vectors and multidate Landsat TM imagery to monitor land-use change. Results confirm the importance of field-based accuracy assessment to identify problems in a land-use map and to improve area estimates for each class.
This paper analyzes the relation between satellite‐based measures of vegetation greenness and climate by land cover type at a regional scale (2° × 2° grid boxes) between 1982 and 1999. We use the ...normalized difference vegetation index (NDVI) from the Global Inventory Monitoring and Modeling Studies (GIMMS) data set to quantify climate‐induced changes in terrestrial vegetation. Climatic conditions are represented with monthly data for land surface air temperature and precipitation. The relation between NDVI and the climate variables is represented using a quadratic specification, which is consistent with the notion of a physiological optimum. The effects of spatial heterogeneity and unobserved variables are estimated with specifications and statistical techniques that allow coefficients to vary among grid boxes. Using this methodology, we are able to estimate statistically meaningful relations between NDVI and climate during spring, summer, and autumn for forests between 40°N and 70°N in North America and Eurasia. Of the variables examined, changes in temperature account for the largest fraction of the change in NDVI between the early 1980s and the late 1990s. Changes in stratospheric aerosol optical depth and precipitation have a smaller effect, while artifacts associated with variations in solar zenith angle are negligible. These results indicate that temperature changes between the early 1980s and the late 1990s are responsible for much of the observed increase in satellite measures of northern forest greenness.
The relation between satellite measurements of the normalized difference vegetation index (NDVI), cumulated over the growing season, and inventory estimates of forest woody biomass carbon is ...estimated statistically with data from 167 provinces and states in six countries (Canada, Finland, Norway, Russia and the USA for a single time period and Sweden for two periods). Statistical tests indicate that the regression model can be used to represent the relation between forest biomass and NDVI across spatial, temporal and ecological scales for relatively long time scales. For the 1.42 billion ha of boreal and temperate forests in the Northern Hemisphere, the woody biomass carbon pools and sinks are estimated at a relatively high spatial resolution (8×8 km). We estimate the carbon pool to be 61±20 gigatons (10
9) carbon (Gt C) during the late 1990s and the biomass sink to be 0.68±0.34 Gt C/year between the 1982 and 1999. The geographic detail of carbon sinks provided here can contribute to a potential monitoring program for greenhouse gas emission reduction commitments under the Kyoto Protocol.
Because intramedullary spinal cord metastasis is often a difficult diagnosis to make, our purpose was to perform a systematic review of the MR imaging and relevant baseline clinical features of ...intramedullary spinal cord metastases in a large series.
Consecutive patients with intramedullary spinal cord metastasis with available pretreatment digital MR imaging examinations were identified. The MR imaging examination(s) for each patient was reviewed by 2 neuroradiologists for various imaging characteristics. Relevant clinical data were obtained.
Forty-nine patients had 70 intramedullary spinal cord metastases, with 10 (20%) having multiple intramedullary spinal cord metastases; 8% (4/49) were asymptomatic. Primary tumor diagnosis was preceded by intramedullary spinal cord metastasis presentation in 20% (10/49) and by intramedullary spinal cord metastasis diagnosis in 10% (5/49); 98% (63/64) of intramedullary spinal cord metastases enhanced. Cord edema was extensive: mean, 4.5 segments, 3.6-fold larger than enhancing lesion, and ≥3 segments in 54% (37/69). Intratumoral cystic change was seen in 3% (2/70) and hemorrhage in 1% (1/70); 59% (29/49) of reference MR imaging examinations displayed other CNS or spinal (non-spinal cord) metastases, and 59% (29/49) exhibited the primary tumor/non-CNS metastases, with 88% (43/49) displaying ≥1 finding and 31% (15/49) displaying both findings. Patients with solitary intramedullary spinal cord metastasis were less likely than those with multiple intramedullary spinal cord metastases to have other CNS or spinal (non-spinal cord) metastases on the reference MR imaging (20/39 51% versus 9/10 90%, respectively; P = .0263).
Lack of known primary malignancy or spinal cord symptoms should not discourage consideration of intramedullary spinal cord metastasis. Enhancement and extensive edema for lesion size (often ≥3 segments) are typical for intramedullary spinal cord metastasis. Presence of cystic change/hemorrhage makes intramedullary spinal cord metastasis unlikely. Evidence for other CNS or spinal (non-spinal cord) metastases and the primary tumor/non-CNS metastases are common. The prevalence of other CNS or spinal (non-spinal cord) metastases in those with multiple intramedullary spinal cord metastases is especially high.
We revisit the issue of asymmetries in the relation between the price of crude oil and refined petroleum products in the United States. An econometric analysis of monthly data indicates that the ...asymmetric relation between the price of crude oil and motor gasoline is generated by refinery utilization rates and inventory behavior. The asymmetric relation between the price of crude oil and home heating oil probably is generated by contractual arrangements between retailers and consumers. Together, these results imply that price asymmetries may be generated by efficient markets. Under these conditions, there is little justification for policy interventions to reduce or eliminate price asymmetries in motor gasoline and home heating oil markets.
Image-guided cervical transforaminal epidural injections play an important role in the management of cervical radicular pain syndromes. The safety and efficacy of these injections via an ...anterolateral approach has been well-studied. The goal of this retrospective review was to determine the safety and efficacy of CT-guided transforaminal epidural injections by using a posterior approach.
Retrospective review of patient records was used to define VNPS and RMDI of patients undergoing CT-guided transforaminal cervical epidural injections between 2006 and 2010. Pain scores were recorded preprocedure, immediately postprocedure, at 2 weeks, and at 2 months. The RMDI was recorded preprocedure, at 2 weeks, and at 2 months. Data analysis of 247 patients was completed. Differences in VNPS scores and the RMDI were then compared on the basis of a CT-guided approach (anterolateral versus posterior).
There was no statistical difference in the degree of pain relief and improvement in the RMDI between the CT-guided transforaminal anterolateral approach and the posterior approach at 2 weeks and at 2 months. Both groups demonstrated a statistically significant improvement in pain scores and the RMDI. Approximately 35% of patients in both groups demonstrated >50% pain relief at 2 months. There were no serious complications in either group.
CT-guided transforaminal cervical epidural injections by using a posterior approach are safe and effective.
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