scholarly journals Eigenvalue estimates and asymptotics for weighted pseudodifferential operators with singular measures in the critical case

2021 ◽  
pp. 331-354
Author(s):  
Grigori Rozenblum ◽  
Eugene Shargorodsky
Keyword(s):  
Critical Case ◽  
Pseudodifferential Operators ◽  
Eigenvalue Estimates ◽  
Singular Measures

Qualities of a good essay: an assessment of the writings of Nigerian undergraduates

2020 ◽  
Vol 3 (7) ◽  
pp. 82-88
Author(s):  
Usoro Mark Okono
Keyword(s):  
Critical Case ◽  
State University ◽  
Descriptive Linguistics ◽  
Purposive Sampling ◽  
Writing Test ◽  
Units Of Analysis ◽  
Regular Practice

This research sought to discover the capabilities of Nigerian undergraduates in handling the salient characteristics of essay in English. Such qualities as clarity, economy, simplicity, unity and coherence were the variables in the assessment. The study was conducted within the framework of the theory of descriptive linguistics and its sub-discipline of stylistics. Four topics representing argumentative, descriptive, expository and narrative essays were given to students for each of them to voluntarily choose one and write on in a strictly supervised writing test. All the essays were marked on the above stated variables. Critical case sampling strand of the purposive sampling was used to select four outstanding essays each representing one of the four departments of the Akwa Ibom State University of Nigeria. Paragraph and sentence formed some of the units of analysis. It was found out that the four subjects whose essays were analyzed proved their mettle in producing readable and creative prose in the four genres with some room for improvement. It is suggested that the Use of English programme in Nigerian universities should be extended from one to two years in addition to regular practice in writing by students and feedback from lecturers.

Pseudodifferential operators on differential groupoids

1999 ◽  
Vol 189 (1) ◽  
pp. 117-152 ◽  
Author(s):  
Victor Nistor ◽  
Alan Weinstein ◽  
Ping Xu
Keyword(s):  
Pseudodifferential Operators

scholarly journals Publications about Women, Science, and Engineering: Use of Sex and Gender in Titles over a Forty-six-year Period

2021 ◽  
pp. 016224392110276
Author(s):  
Mary Frank Fox ◽  
Diana Roldan Rueda ◽  
Gerhard Sonnert ◽  
Amanda Nabors ◽  
Sarah Bartel
Keyword(s):  
Social Stratification ◽  
Critical Case ◽  
Social Inequalities ◽  
Sex And Gender ◽  
Science And Engineering ◽  
Analytical Issue ◽  
Key Features ◽  
And Gender ◽  
Science Policies

This article focuses on key features of the use of sex and gender in titles of articles about women, science, and engineering over an important forty-six-year period (1965–2010). The focus is theoretically and empirically consequential. Theoretically, the paper addresses science as a critical case that connects femininity/masculinity to social stratification; and the use of sex and gender as an enduring, analytical issue that reveals perspectives on hierarchies of femininity/masculinity. Empirically, this article identifies the emergence, development, and stabilization of published articles about women, science, and engineering that use sex and gender in their titles. The distinctive method involves search, retrieval, and review of 23,430 articles, using intercoder reliabilities for inclusion/exclusion. This results in a uniquely specified and comprehensive set of articles on our subject and the identification of titles with sex and gender. Findings point to (1) the growth of gender titles, (2) their increase in every field, (3) differing concentrations of sex and gender titles in journals, (4) a span of telling topic areas, and (5) higher citation rates of gender, compared to sex, titles. Broader implications appear in reasons for the growth of gender titles, meanings of topic areas that occur, insights into social inequalities and science policies, and emerging complexities of nonbinary categories of sex/gender.

Rurality and Party System Fragmentation in the Nigerian Presidential Elections of the Fourth Republic

2020 ◽  
Vol 11 (1) ◽  
pp. 59-85
Author(s):  
Cletus Famous Nwankwo
Keyword(s):  
Presidential Elections ◽  
Party System ◽  
Party Systems ◽  
Voting Behaviour ◽  
Composite Measure ◽  
Singular Measures ◽  
Rural And Urban ◽  
Fourth Republic ◽  
Cast Doubt ◽  
Negative Effect

AbstractThis paper examines the effect of rurality on party system fragmentation in the Nigerian presidential elections of the fourth republic. The findings show that party system fragmentation (PSF) has been characteristically low in the Nigerian presidential elections and rurality does not significantly predict party system fragmentation. Rurality has a negative effect on PSF in all the elections studied except the 2003 election but only significant in the 2011 poll. Thus, the paper cast doubt on previous studies that indicate that striking rural-urban differences manifest in party system fragmentation in African elections and attribute it to previous studies’ measure of rurality. The paper argues that the use of a composite measure of rurality instead of singular measures of rurality might provide better analysis that helps us understand the effect of rurality on party systems. Also, it argues that in the study of the rural-urban difference in voting behaviour or political behaviours more broadly, data should be aggregated based on cities and non-city areas because cities have distinctive urban characters compared with non-city places. Analyses done on states or constituencies level may not reveal the rural-urban difference because states and constituencies usually have a mix of rural and urban population and other characteristics.

scholarly journals Sharp thresholds of blow-up and global existence for the Schrödinger equation with combined power-type and Choquard-type nonlinearities

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Yongbin Wang ◽  
Binhua Feng
Keyword(s):  
Global Existence ◽  
Finite Time ◽  
Critical Case ◽  
Blow Up ◽  
Critical Mass ◽  
Choquard Equation ◽  
Power Type ◽  
Scale Invariant ◽  
Nonlinear Schrödinger ◽  
Sharp Thresholds

AbstractIn this paper, we consider the sharp thresholds of blow-up and global existence for the nonlinear Schrödinger–Choquard equation $$ i\psi _{t}+\Delta \psi =\lambda _{1} \vert \psi \vert ^{p_{1}}\psi +\lambda _{2}\bigl(I _{\alpha } \ast \vert \psi \vert ^{p_{2}}\bigr) \vert \psi \vert ^{p_{2}-2}\psi . $$iψt+Δψ=λ1|ψ|p1ψ+λ2(Iα∗|ψ|p2)|ψ|p2−2ψ. We derive some finite time blow-up results. Due to the failure of this equation to be scale invariant, we obtain some sharp thresholds of blow-up and global existence by constructing some new estimates. In particular, we prove the global existence for this equation with critical mass in the $L^{2}$L2-critical case. Our obtained results extend and improve some recent results.

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