337 research outputs found

    Use of the Hedonic Method to Estimate Lake Sedimentation Impacts on Property Values in Mountain Park and Roswell, GA

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    Metropolitan Atlanta has experienced explosive population growth in the past few decades, which has resulted in rapid residential growth. The City of Roswell is one the best examples of residential growth on the urban fringe of Atlanta, with its housing stock increasing by more than 50 percent from 1990 to 2000. Stormwater runoff created from these development sites is expected to be causing sedimentation accumulation in lakes within Roswell and a neighboring, downstream wildlife refuge located in the City of Mountain Park. Because sedimentation tends to fill-in and shrink lakes, our results provide some indication of the potential property damages associated with sedimentation. Furthermore, our results provide evidence that lake value is not monotonically increasing with lake size, which is believed to be due to the influence that geographic, environmental, and social factors have on the degree to which lakes add value to housing prices.Land Economics/Use,

    Tide Gauges: From single hazard to multi-hazard warning systems

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    As the name suggests, tide gauges were originally devised for the singular purpose of monitoring tidal fluctuations in sea level in order to aid safe navigation and port operations. Early tide gauges, such as that used by the famous dockmaster William Hutchinson at Liverpool in the late eighteenth century, consisted of little more than graduated markers on sea walls or posts, against which the sea surface could be measured by eye (Figure 1). These were used to record and then forecast the times and heights of high and low water each day; printed in local tide tables, they provided rudimentary information on variations in the tide

    Common neural basis of motor sequence learning and word recognition and its relation with individual differences in reading skill

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    To investigate the neural basis of a common statistical learning mechanism involved in motor sequence learning and decoding, we recorded brain activation from participants during a serial reaction time (SRT) task and a word reading task using functional magnetic resonance imaging. In the SRT task, a manual response was made depending on the location of a visual cue, and the order of the locations was either fixed or random. In the word reading task, visual words were passively presented. In the inferior frontal gyrus pars triangularis (IFGpTr) and the insula, differences in activation between the ordered and random condition in the SRT task and activation to printed words in the word reading task were correlated with the participants' decoding ability. We speculate that extraction of statistically predictable patterns in the IFGpTr and insula contributes to both motor sequence learning and orthographic learning, and therefore predicts individual differences in decoding skill

    Perceptions of US adolescents and adults with sickle cell disease on their quality of care

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    Importance: Sickle cell disease (SCD) is the most common inherited red blood cell disorder in the United States, and previous studies have shown that individuals with SCD are affected by multiple health disparities, including stigmatization, inequities in funding, and worse health outcomes, which may preclude their ability to access quality health care. This needs assessment was performed as part of the Sickle Cell Disease Implementation Consortium (SCDIC) to assess barriers to care that may be faced by individuals with SCD. Objective: To assess the SCD-related medical care experience of adolescents and adults with SCD. Design, Setting, and Participants: This one-time survey study evaluated pain interference, quality of health care, and self-efficacy of 440 adults and adolescents (aged 15 to 50 years) with SCD of all genotypes and assessed how these variables were associated with their perceptions of outpatient and emergency department (ED) care. The surveys were administered once during office visits by trained study coordinators at 7 of 8 SCDIC sites in 2018. Results: The SCDIC sites did not report the number of individuals approached to participate in this study; thus, a response rate could not be calculated. In addition, respondents were not required to answer every question in the survey; thus, the response rate per question differed for each variable. Of 440 individuals with SCD, participants were primarily female (245 [55.7%]) and African American (428 [97.3%]) individuals, with a mean (SD) age of 27.8 (8.6) years. The majority of participants (306 of 435 [70.3%]) had hemoglobin SS or hemoglobin S β0-thalassemia. Most respondents (361 of 437 [82.6%]) reported access to nonacute (usual) SCD care, and the majority of respondents (382 of 413 [92.1%]) noted satisfaction with their usual care physician. Of 435 participants, 287 (66.0%) reported requiring an ED visit for acute pain in the previous year. Respondents were less pleased with their ED care than their usual care clinician, with approximately half (146 of 287 [50.9%]) being satisfied with or perceiving having adequate quality care in the ED. Participants also noted that when they experienced severe pain or clinician lack of empathy, this was associated with a negative quality of care. Age group was associated with ED satisfaction, with younger patients (\u3c19 vs 19-30 and 31-50 years) reporting better ED experiences. Conclusions and Relevance: These results suggested that a negative perception of care may be a barrier for patients seeking care. These findings underscore the necessity of implementation studies to improve access to quality care for this population, especially in the acute care setting

    Arginine to glutamine variant in olfactomedin-like 3 (OLFML3) is a candidate for severe goniodysgenesis and glaucoma in the Border Collie dog breed

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    Goniodysgenesis is a developmental abnormality of the anterior chamber of the eye. It is generally considered to be congenital in dogs (), and has been associated with glaucoma and blindness. Goniodysgenesis and early-onset glaucoma initially emerged in Border Collies in Australia in the late 1990s and have subsequently been found in this breed in Europe and the USA. The objective of the present study was to determine the genetic basis of goniodysgenesis in Border Collies. Clinical diagnosis was based on results of examinations by veterinary ophthalmologists of affected and unaffected dogs from eleven different countries. Genotyping using the Illumina high density canine single nucleotide variant genotyping chip was used to identify a candidate genetic region. There was a highly significant peak of association over chromosome 17, with a -value of 2 × 10 Expression profiles and evolutionary conservation of candidate genes were assessed using public databases. Whole genome sequences of three dogs with glaucoma, three severely affected by goniodysgenesis and three unaffected dogs identified a missense variant in the olfactomedin like 3 () gene in all six affected animals. This was homozygous for the risk allele in all nine cases with glaucoma and 12 of 14 other severely affected animals. Of 67 reportedly unaffected animals, only one was homozygous for this variant (offspring of parents both with goniodysgenesis who were also homozygous for the variant). Analysis of pedigree information was consistent with an autosomal recessive mode of inheritance for severe goniodysgenesis (potentially leading to glaucoma) in this breed. The identification of a candidate genetic region and putative causative variant will aid breeders to reduce the frequency of goniodysgenesis and the risk of glaucoma in the Border Collie population

    Recent Activities on Tristan da Cunha Island: Geodetic Installations, Local Tie Measurements and their Analysis

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    During 2017 a team from the University of Luxembourg and the National Oceanography Centre, Liverpool, established a permanent Global Navigation Satellite System (GNSS) station and two new tide gauges on Tristan da Cunha Island in the South Atlantic Ocean. These installations were funded through various projects at both collaborating institutions under the umbrella of the International GNSS Service (IGS) Tide Gauge Benchmark Monitoring (TIGA) Working Group and the Global Geodetic Observing System (GGOS) focus area on Sea Level Change, Variability and Forecasting. While this was the first scientific installation of a GNSS station on the main island within the Tristan da Cunha archipelago, IGS station GOUG, located on Gough Island which lies 412 km to the south, has been in operation since 1998. Unfortunately GOUG was decommissioned in 2018. Sea level observations on Tristan da Cunha have a longer history than GNSS with various tide gauges having been in operation since 1984. Tristan da Cunha also hosts a Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) station which was established in 2012 after a previous installation was upgraded and moved to the current site. The antenna TCTA is located on the concrete monument of the previous DORIS antenna. Furthermore, in order for future International Terrestrial Reference Frame (ITRF) computations to fully benefit from the proximity of the sensors, the geodetic ties between the respective antennas (and reference markers in case of the tide gauges) need to be determined at the millimeter level using various terrestrial surveying methods and a local benchmark network. This contribution provides details of the activities on Tristan da Cunha including the installations, the established benchmark network, the terrestrial surveys of the geodetic ties and the analysis of these measurements in order to geometrically link the GNSS and DORIS antennas to each other as well as to the tide gauges

    Particle concentration measurement and flow regime identification in multiphase pipe flow using a generalised dual-frequency inversion method

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    An acoustic particle concentration measurement method, originally developed for marine sediment, in which the backscattered energy received by emitter-receiver transducers in the megahertz range is used to construct concentration profiles in suspensions of solid particles in a carrier fluid is applied to suspensions of general engineering interest. Four particle species with range of densities and sizes are used. Concentration profiles in horizontal, turbulent pipe flow at a Reynolds number of 50,000 and three nominal volume fractions are presented for each particle species, using experimentally determined acoustic coefficients, in order to isolate the influence of particle size and density on transport and settling in solid-liquid multiphase flows. It is clear from the results that the method allows the degree of segregation in real suspensions and slurries to be measured, and has a range of potential applications in the nuclear and minerals processing industries, for example. Lastly, the limiting conditions of the method are explored through the concept of an acoustic penetration depth

    A randomized trial of bevacizumab for newly diagnosed glioblastoma.

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    BACKGROUND: Concurrent treatment with temozolomide and radiotherapy followed by maintenance temozolomide is the standard of care for patients with newly diagnosed glioblastoma. Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor A, is currently approved for recurrent glioblastoma. Whether the addition of bevacizumab would improve survival among patients with newly diagnosed glioblastoma is not known. METHODS: In this randomized, double-blind, placebo-controlled trial, we treated adults who had centrally confirmed glioblastoma with radiotherapy (60 Gy) and daily temozolomide. Treatment with bevacizumab or placebo began during week 4 of radiotherapy and was continued for up to 12 cycles of maintenance chemotherapy. At disease progression, the assigned treatment was revealed, and bevacizumab therapy could be initiated or continued. The trial was designed to detect a 25% reduction in the risk of death and a 30% reduction in the risk of progression or death, the two coprimary end points, with the addition of bevacizumab. RESULTS: A total of 978 patients were registered, and 637 underwent randomization. There was no significant difference in the duration of overall survival between the bevacizumab group and the placebo group (median, 15.7 and 16.1 months, respectively; hazard ratio for death in the bevacizumab group, 1.13). Progression-free survival was longer in the bevacizumab group (10.7 months vs. 7.3 months; hazard ratio for progression or death, 0.79). There were modest increases in rates of hypertension, thromboembolic events, intestinal perforation, and neutropenia in the bevacizumab group. Over time, an increased symptom burden, a worse quality of life, and a decline in neurocognitive function were more frequent in the bevacizumab group. CONCLUSIONS: First-line use of bevacizumab did not improve overall survival in patients with newly diagnosed glioblastoma. Progression-free survival was prolonged but did not reach the prespecified improvement target. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00884741.)
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