2,676 research outputs found
Effects of Forestland Ownership Conversion on Greenhouse Gas Emissions: The Case of South Korea
This research analyzed the effects of forestland conversion from private to public ownership on greenhouse gas emissions by quantifying the relationship between forestland ownership conversion and deforestation, and then examining the effects of the change in deforestation on greenhouse gas emissions in South Korea. Ex ante simulations forecast greenhouse gas emissions resulting from deforestation rates under the current level of national forestland and three scenarios of increased percentages of national forestland. The findings suggest that increasing the percentage of national forestland would mitigate the increase in the deforestation rate, which in turn would moderate the increase in greenhouse gas emissions.greenhouse gas emissions, Forestland Ownership, Environmental Economics and Policy, Q15, Q23, Q24, Q54,
Impacts of Highway Infrastructure Investment Under the American Recovery and Reinvestment Act
This study evaluated the impact on highway demand of highway disbursements under the American Recovery and Reinvestment Act (ARRA). Vehicle miles traveled were used to estimate a highway demand equation employing a spatial Durbin model for the 48 contiguous U.S. states during 1994-2008. Estimates from the equation were used to test the hypothesis that highway disbursements caused different upward shifts in the highway demand curves of states. We estimated 27.2 billion in ARRA highway disbursements, yielding an average net benefit of $0.30 per dollar spent
A Case of Primary Paraganglioma that Arose in the Pancreas: the Color Doppler Ultrasonography and Dynamic CT Features
Paragangliomas rarely originate from the pancreas and they are characterized on imaging studies as well-marginated, hypervascular masses with cystic areas. We herein report on a case report of pancreatic paraganglioma in a 57-year-old woman, which was confirmed on pathology. Color Doppler ultrasonography and dynamic CT demonstrated a well-demarcated, extremely hypervascular mass with prominent intratumoral vessels and early contrast filling of the draining veins from the mass. Endoscopic retrograde cholangiopancreatography showed that the main pancreatic duct was displaced and mildly dilated
Iterative in Situ Click Chemistry Assembles a Branched Capture Agent and Allosteric Inhibitor for Akt1
We describe the use of iterative in situ click chemistry to design an Akt-specific branched peptide triligand that is a drop-in replacement for monoclonal antibodies in multiple biochemical assays. Each peptide module in the branched structure makes unique contributions to affinity and/or specificity resulting in a 200 nM affinity ligand that efficiently immunoprecipitates Akt from cancer cell lysates and labels Akt in fixed cells. Our use of a small molecule to preinhibit Akt prior to screening resulted in low micromolar inhibitory potency and an allosteric mode of inhibition, which is evidenced through a series of competitive enzyme kinetic assays. To demonstrate the efficiency and selectivity of the protein-templated in situ click reaction, we developed a novel QPCR-based methodology that enabled a quantitative assessment of its yield. These results point to the potential for iterative in situ click chemistry to generate potent, synthetically accessible antibody replacements with novel inhibitory properties
Delayed surgical intervention in central cord syndrome with cervical stenosis
Study DesignâReview of the literature. ObjectiveâIt is generally accepted that surgical treatment is necessary for central cord syndrome (CCS) with an underlying cervical stenosis. However, the surgical timing for decompression is controversial in spondylotic cervical CCS. The purpose of this study is to review the results of early and delayed surgery in patients with spondylotic cervical CCS. MethodsâMEDLINE was searched for English-language articles on CCS. There were 1,653 articles from 1940 to 2012 regarding CCS, 5 of which dealt with the timing of surgery for spondylotic cervical CCS. ResultsâAll five reports regarding the surgical timing of spondylotic cervical CCS were retrospective. Motor improvement, functional independence measures, and walking ability showed similar improvement in early and late surgery groups in the studies with follow-up longer than 1 year. However, greater improvement was seen in the early surgery group in the studies with follow-up shorter than 1 year. The complication rates did not show a difference between the early and late surgery groups. However, there are controversies regarding the length of intensive care unit stay or hospital stay for the two groups. ConclusionsâThere was no difference in motor improvement, functional independence, walking ability, and complication rates between early and late surgery for spondylotic cervical CCS
Asymptomatic stenosis in the cervical and thoracic spines of patients with symptomatic lumbar stenosis
Study DesignâRetrospective study. ObjectiveâStudies on age-related degenerative changes causing concurrent stenoses in the cervical, thoracic, and lumbar spines (triple stenosis) are rare in the literature. Our objectives were to determine: (1) the incidence of asymptomatic radiologic cervical and thoracic stenosis in elderly patients with symptomatic lumbar stenosis, (2) the incidence of concurrent radiologic spinal stenosis in the cervical and thoracic spines, and (3) the radiologic features of cervical stenosis that might predict concurrent thoracic stenosis. MethodsâWhole-spine T2 sagittal magnetic resonance images of patients older than 80 and diagnosed with lumbar spinal stenosis between January 2003 and January 2012 were evaluated retrospectively. We included patients with asymptomatic spondylotic cervical and thoracic stenosis. We measured the anteroposterior diameters of the vertebral body, bony spinal canal, and spinal cord, along with the Pavlov ratio and anterior or posterior epidural stenosis at the level of the disk for each cervical and thoracic level. We compared the radiologic parameters between the subgroups of cervical stenosis with and without thoracic stenosis. ResultsâAmong the 460 patients with lumbar stenosis, 110 (23.9%) had concurrent radiologic cervical stenosis and 112 (24.3%) had concurrent radiologic thoracic stenosis. Fifty-six patients (12.1%) had combined radiologic cervical and thoracic stenosis in addition to their symptomatic lumbar stenosis (triple stenosis). Anterior epidural stenosis at C7âT1 was associated with a high prevalence of thoracic stenosis. ConclusionsâIt appears that asymptomatic radiologic cervical and thoracic stenosis is common in elderly patients with symptomatic lumbar stenosis
Age-related changes in cervical sagittal range of motion and alignment
Study DesignâRetrospective cohort study. ObjectiveâTo compare sagittal cervical range of motion (ROM) and alignment in young versus middle-aged adults. MethodsâOne hundred four asymptomatic adults were selected randomly out of 791 subjects who underwent lateral cervical radiographs in neutral, flexion, and extension positions. They were divided into two groups: young (age 20 to 29, 52 people) and middle-aged adults (age 50 to 59, 52 people). We determined the ROMs of upper cervical (occipitalâC2 angle), midcervical (C2âC7 angle), and cervicothoracic spine (cervicosternal angle). We compared the alignment differences of the two groups by calculating the distances between C2 and C7 plumb lines, and C2 central-offset distance. ResultsâIn neutral position, there was no significant difference between young and middle-aged adults. However, in flexion, C2âC7 angle, distance between C2âC7 plumb lines, and C2 central-offset distance decreased with age. In extension, C2âC7 angle and C2 central-offset distance decreased with age. During flexion and extension, midcervical ROM and the range of C2 central-offset distance decreased in the middle-aged group. However, there was no difference between the two age groups in the ROM of the upper cervical and the cervicothoracic regions during flexion and extension. ConclusionâWe found that, despite of the presence of age-related cervical alignment changes, the only difference between the two groups was in the sagittal ROM of the midcervical spine during flexion and extension. Only the ROM of the midcervical spine appears to change significantly, consistent with findings that these levels are most likely to develop both symptomatic and asymptomatic degenerative changes
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