154 research outputs found
Eurasia advantage, not genetic diversity: against Ashraf and Galor's "Genetic Diversity" Hypothesis
Ashraf and Galor (2012) advanced the bold thesis that genetic diversity within different human populations has been a foundational determinant of long-run economic development. We show that their results are not robust after controlling for a key missing variable - the Eurasia dummy. After controlling for the Eurasia dummy, all indicators of genetic diversity lose statistical significance in regressions with indicators of economic development as dependent variables. Ashraf and Galor's statistical results merely "reflect" - literally - Eurasia's unique advantage in supporting economic development that was mostly based on settled agriculture until about AD1500
Online Appendix to: Eurasia Advantage, not Genetic Diversity: Against Ashraf and Galor's "Genetic Diversity" Hypothesis
Ashraf and Galor (2012) advanced the bold thesis that genetic diversity within different human populations has been a foundational determinant of long-run economic development. In the HSR article "Eurasia Advantage, not Genetic Diversity: Against Ashraf and Galor’s 'Genetic Diversity' Hypothesis," we show that their results are not robust after controlling for a key missing variable - the Eurasia dummy. After controlling for the Eurasia dummy, all indicators of genetic diversity lose statistical significance in regressions with indicators of economic development as dependent variables. Ashraf and Galor's statistical results merely "reflect" - literally - Eurasia's unique advantage in supporting economic development that was mostly based on settled agriculture until about AD1500. The appendices included in this volume of HSR Trans complement the following article: Shiping Tang, 2016, Eurasia Advantage, not Genetic Diversity: Against Ashraf and Galor's "Genetic Diversity" Hypothesis, Historical Social Research 41 (1): 287-327. doi: http://dx.doi.org/10.12759/hsr.41.2016.1.287-327
Detection of Dissolved Carbon Monoxide in Transformer Oil Using 1.567  μ
Carbon monoxide (CO) is one of the most important fault characteristic gases dissolved in power transformer oil. With the advantages of high sensitivity and accuracy, long-term stability, and short detection time, photoacoustic spectroscopy (PAS) has been proven to be one promising sensing technology for trace gas recognition. In this investigation, a tunable PAS experimental system based on a distributed-feedback (DFB) diode laser was proposed for recognizing dissolved CO in transformer oil. The molecular spectral line of CO gas detection was selected at 1.567 μm in the whole experiment. Relationships between the photoacoustic (PA) signal and gas pressure, temperature, laser power, and CO gas concentration were measured and discussed in detail, respectively. Finally, based on the least square regression theory, a novel quantitative identification method for CO gas detection with the PAS experimental system was proposed. And a comparative research about the gas detection performances performed by the PAS system and gas chromatography (GC) measurement was presented. All results lay a solid foundation for exploring a portable and tunable CO gas PAS detection device for practical application in future
Predictors of permanent pacemaker implantation in aortic valve diseases after TAVI with vitaFlow liberty system
IntroductionPermanent pacemaker implantation (PPI) is a known complication in patients with aortic stenosis following transcatheter aortic valve implantation (TAVI). However, there is limited research on TAVI for pure aortic regurgitation (PAR), and more investigation is needed to determine the occurrence of postoperative cardiac conduction block and the need for PPI in this population. Therefore, this retrospective analysis aimed to evaluate the incidence of cardiac conduction block and the necessity of PPI after TAVI in patients with different types of aortic valve disease, including pure aortic stenosis (PAS), aortic stenosis with regurgitation (ASR), and PAR.MethodsClinical data of 100 patients who TAVI were analyzed retrospectively. The incidence of conduction block was assessed, and clinical factors were examined to predict the necessity of PPI.ResultsCardiac conduction block was found to be a common complication following TAVI, particularly in patients with PAR. PAR was identified as an independent risk factor for requiring PPI. Additionally, first-degree atrioventricular block emerged as a sensitive predictor for PPI in patients with PAR.DiscussionThese findings provide valuable insights into the safety and effectiveness of TAVI, which can help enhance patient management and reduce complications
Upconversion Luminescence and Magnetic Turning of NaLuF 4
Fluorescent and magnetic bifunctional NaLuF4:Yb3+/Tm3+/Gd3+ nanocrystals were synthesized by the solvothermal method and subsequent surface modification. By changing the doping concentration of Gd3+, the shape, size, luminescent properties, and magnetic properties of the nanoparticles can be modulated. These NaLuF4:Yb3+/Tm3+/Gd3+ nanocrystals present efficient blue upconversion fluorescence and excellent paramagnetic property at room temperature. Based on the luminescence resonance energy transfer (LRET), upconversion nanoparticles (UCNPs) were confirmed to be an efficient fluorescent nanoprobe for detecting acriflavine. It is easy to derive the concentration of acriflavine from the Integral Intensity Ratio of Green (emission from acriflavine) to Blue (emission from UCNPs) fluorescent signals. Based on this upconversion fluorescent nanoprobe, the detection limit of acriflavine can reach up to 0.32 μg/mL
Influence of tree spacing on soil nitrogen mineralization and availability in hybrid poplar plantations
Nitrogen (N) availability and mineralization are key parameters and transformation processes that impact plant growth and forest productivity. We hypothesized that suitable plantation spacing can lead to enhanced soil N mineralization and nitrification, which in turn promote tree growth. Studies were conducted to evaluate seasonal patterns of soil inorganic N pools as well as rates of nitrification and N mineralization of three soil layers under four tree spacing treatments. Results showed tree spacing significantly affected annual net N mineralization, whereas inorganic N content in surface soils was significantly affected by tree spacing only during the growing season. The total annual cumulative net N mineralization ranged from 80.3–136.0 mg·kg−1 in the surface soils (0–20 cm), whereas the cumulative net N mineralization of 6 × 6 m and 4.5 × 8 m spacings was 65% and 24% higher than that of the 5 × 5 m, respectively. In general, tree spacing would affect N availability in soil by altering N mineralization rates, while high annual N mineralization was found in soils of low density plantations, with higher rates in square spacing than rectangular spacing. The obtained results suggest that suitable spacing could lead to enhanced N mineralization, but seasonal variation of soil N mineralization may not only be directly related to plantation productivity but also to understory vegetation productivity.Peer reviewedPlant and Soil Science
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