1,457 research outputs found
Evolution of the Canadian Tax Reform
The passage of the Tax Reform Bill in December 1971 marked the end of an extraordinary decade of inquiry and debate on federal tax reform in Canada. Minor (and some major) changes are still being made, and a further instalment of reform is to be expected in the area of sales taxation. The more controversial issues of tax reform in the field of income taxation have, however, been finally settled, at least for the next few years and probably for a much longer period. While business firms, families and the government wrestle with the complexities of the new system, it is therefore time to sit back and review this remarkable episode in Canadian public finance history. Three main stages can be distinguished in the evolution of the reform to 1971. The first began with the appointment of the Carter Royal Commission in 1962 and ended with the presentation of the Carter Report in February, 1967.\u27 The second began when the Minister of Finance invited public submissions and discussion on the Carter Report and ended after a lively public debate and prolonged government study with the publication of the Benson White Paper in November, 1969.2 The third and final stage was the White Paper process of public and parliamentary discussion of the Benson White Paper ending with the introduction of the detailed legislation in June 1971 and its eventual passage in December 1971.\u27 In the following sections we shall consider the development at each of these three stages in turn
Photoelectrochemical Characterization and Durability Analysis of GaInPN Epilayers
Epilayer samples of GaInPN with a stoichiometry of Ga.962In.038P.976N.024 and Ga.95In.05P.975N.025 were grown by metallorganic chemical vapor deposition and were photoelectrochemically characterized to determine their potential to photoelectrolyze water.
The materials had direct transition bandgap energies of _2.0 eV, as determined by photocurrent spectroscopy; however, the measured flatband potentials were several hundred millivolts too negative for unbiased water splitting. Stability was assessed by operating the electrodes as photocathodes for 24 h and qualitatively evaluated by probing the amount of surface etching with a stylus profilometer. Quantitative evaluation was done by measuring the concentration of gallium in the corrosion test electrolyte using inductively coupled plasma mass spectrometry. Results were compared to similarly treated GaP and GaInP2 samples for context
Hepatitis C virus NS3/4A inhibitors and other drug-like compounds as covalent binders of SARS-CoV-2 main protease
Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), threatens global public health. The world needs rapid development of new antivirals and vaccines to control the current pandemic and to control the spread of the variants. Among the proteins synthesized by the SARS-CoV-2 genome, main protease (Mpro also known as 3CLpro) is a primary drug target, due to its essential role in maturation of the viral polyproteins. In this study, we provide crystallographic evidence, along with some binding assay data, that three clinically approved anti hepatitis C virus drugs and two other drug-like compounds covalently bind to the Mpro Cys145 catalytic residue in the active site. Also, molecular docking studies can provide additional insight for the design of new antiviral inhibitors for SARS-CoV-2 using these drugs as lead compounds. One might consider derivatives of these lead compounds with higher affinity to the Mpro as potential COVID-19 therapeutics for further testing and possibly clinical trials
Landscape science: a Russian geographical tradition
The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability
Search for first generation leptoquark pair production in the electron + missing energy + jets final state
We present a search for the pair production of first generation scalar
leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4
fb collected with the D0 detector at the Fermilab Tevatron Collider in
ppbar collisions at TeV. In the channel , where q, q' are u or d quarks, no significant excess
of data over background is observed, and we set a 95% C.L. lower limit of 326
GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays
to eq and .Comment: 7 pages, 6 figures, submitted to PRD-R
Improving coronary artery bypass grafting: a systematic review and meta-analysis on the impact of adopting transit-time flow measurement
Despite there being numerous studies of intraoperative graft flow assessment by transit-time flow measurement (TTFM) on outcomes after
coronary artery bypass grafting (CABG), the adoption of contemporary TTFM is low. Therefore, on 31 January 2018, a systematic literature
search was performed to identify articles that reported (i) the amount of grafts classified as abnormal or which were revised or (ii) an association between TTFM and outcomes during follow-up. Random-effects models were used to create pooled estimates with 95% confidence intervals (CI) of (i) the rate of graft revision per patient, (ii) the rate of graft revision per graft and (iii) the rate of graft revision among
grafts deemed abnormal based on TTFM parameters. The search yielded 242 articles, and 66 original articles were included in the systematic review. Of those articles, 35 studies reported on abnormal grafts or graft revisions (8943 patients, 15 673 grafts) and were included in the meta-analysis. In 4.3% of patients (95% CI 3.3–5.7%, I
2 = 73.9) a revision was required and 2.0% of grafts (95% CI 1.5–2.5%; I
2
= 66.0)
were revised. The pooled rate of graft revisions among abnormal grafts was 25.1% (95% CI 15.5–37.9%; I
2
= 80.2). Studies reported sensitivity ranging from 0.250 to 0.457 and the specificity from 0.939 to 0.984. Reported negative predictive values ranged from 0.719 to 0.980
and reported positive predictive values ranged from 0.100 to 0.840. This systematic review and meta-analysis showed that TTFM could
improve CABG procedures. However, due to heterogeneous data, drawing uniform conclusions appeared challenging. Future studies
should focus on determining the optimal use of TTFM and assessing its diagnostic accuracy
Measurement of the CKM angle γ from a combination of B±→Dh± analyses
A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and
B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of
γ =72.0◦ is found, and confidence intervals are set
γ ∈ [56.4,86.7]◦ at 68% CL,
γ ∈ [42.6,99.6]◦ at 95% CL.
The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦,
and the confidence intervals
γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL
are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ±
decays gives a best-fit value of γ =72.6◦ and the confidence intervals
γ ∈ [55.4,82.3]◦ at 68% CL,
γ ∈ [40.2,92.7]◦ at 95% CL
are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0
mixing
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