A preliminary study of air-pollution measurement by active remote-sensing techniques

Air pollutants are identified, and the needs for their measurement from satellites and aircraft are discussed. An assessment is made of the properties of these pollutants and of the normal atmosphere, including interactions with light of various wavelengths and the resulting effects on transmission and scattering of optical signals. The possible methods for active remote measurement are described; the relative performance capabilities of double-ended and single-ended systems are compared qualitatively; and the capabilities of the several single-ended or backscattering techniques are compared quantitatively. The differential-absorption lidar (DIAL) technique is shown to be superior to the other backscattering techniques. The lidar system parameters and their relationships to the environmental factors and the properties of pollutants are examined in detail. A computer program that models both the atmosphere (including pollutants) and the lidar system is described. The performance capabilities of present and future lidar components are assessed, and projections are made of prospective measurement capabilities for future lidar systems. Following a discussion of some important operational factors that affect both the design and measurement capabilities of airborne and satellite-based lidar systems, the extensive analytical results obtained through more than 1000 individual cases analyzed with the aid of the computer program are summarized and discussed. The conclusions are presented. Recommendations are also made for additional studies to investigate cases that could not be explored adequately during this study

Algorithmic computation of principal posets using Maple and Python

We present symbolic and numerical algorithms for a computer search in the Coxeter spectral classification problems. One of the main aims of the paper is to study finite posets I that are principal, i.e., the rational symmetric Gram matrix GI : = 1/2[CI+CItr] ∈ MI(Q) of I is positive semi-definite of corank one, where CI ∈ MI(Z) is the incidence matrix of I. With any such a connected poset I, we associate a simply laced Euclidean diagram DI ∈ {A˜n, D˜n, E˜₆, E˜₇, E˜₈}, the Coxeter matrix CoxI := −CI ⋅ C−trI, its complex Coxeter spectrum speccI, and a reduced Coxeter number cI. One of our aims is to show that the spectrum speccI of any such a poset I determines the incidence matrix CI (hence the poset I) uniquely, up to a Z-congruence. By computer calculations, we find a complete list of principal one-peak posets I (i.e., I has a unique maximal element) of cardinality ≤ 15, together with speccI, cI, the incidence defect ∂I : ZI → Z, and the Coxeter-Euclidean type DI. In case when DI ∈ {A˜n, D˜n, E˜₆, E˜₇, E˜₈} and n := |I| is relatively small, we show that given such a principal poset I, the incidence matrix CI is Z-congruent with the non-symmetric Gram matrix GˇDI of DI, speccI = speccDI and cˇI = cˇDI. Moreover, given a pair of principal posets I and J, with |I| = |J| ≤ 15, the matrices CI and CJ are Z-congruent if and only if speccI = speccJ

Vitality, Language Use, and Life Satisfaction : A Study of Bilingual Hungarian Adolescents Living in Romania

This study examined the relationship between objective and subjective vitality, in-group language use, and life satisfaction among two groups of bilingual Hungarians adolescents living in Romania: a low objective vitality group from Cluj-Napoca/Kolozsvar, where Hungarians are the demographic minority, and a high objective vitality group from Sfantu Gheorghe/Sepsiszentgyorgy, where Hungarians are the demographic majority. Consistent with predictions, the high objective vitality group reported higher subjective Hungarian vitality, lower subjective Romanian vitality, more frequent use of the Hungarian language, and higher life satisfaction, compared with the low objective vitality group. The effects of objective vitality on language use were partially mediated by subjective Romanian (but not Hungarian) vitality. Conversely, the effects of objective vitality on life satisfaction were fully mediated by subjective Hungarian (but not Romanian) vitality.Peer reviewe

An Assessment of the UK’s Trade with Developing Countries under the Generalised System of Preferences

The European Union (EU) Generalised System of Preferences (GSP Scheme) grants preferential treatment to 88 eligible countries. There are, however, concerns that the restrictive features (such as Rules of Origin, Low Preference Margin and Low Coverage) of the existing scheme indicate gravitation towards commercial trade agenda to which efficiency imperatives appear subordinated. Whether these concerns are genuine is an empirical question whose answer largely determines whether, after Brexit, the UK continues with the existing specifics of the EU scheme or develops a more inclusive UK-specific GSP framework. This study quantitatively examines the efficiency of the EU GSP as it relates to UK beneficiaries from 2014 to 2017. We draw on the descriptive efficiency estimation (The utilisation Rate, Potential Coverage Rate, and the Utility Rate) using import data across 88 beneficiary countries and agricultural products of the Harmonised System Code Chapter 1 to 24. Asides the Rules of Origin that, generally, harm the uptake of GSP, low preference margin is found to cause low utilisation rates in a non-linear manner. Essentially, a more robust option (such that allows “global Cumulation” or broader product coverage) could, substantially, lower the existing barriers to trade and upsurge the efficiency of the GSP scheme

Chromosome changes in human lymphocytes after separate and combined treatment with divalent salts of lead, cadmium, and zinc.

Unstimulated human lymphocytes in whole blood were treated for three hours with lead, cadmium, and zinc acetate separately and in combinations of two or three metal salts with different concentrations of between 10-3 and 10-8 moles, respectively. Untreated cultures and sodium acetate-treated samples served as controls. Chromosome analysis from 48 cultures revealed higher incidences of chromatid-type aberrations and gaps only for cultures exclusively treated with cadmium. The results are discussed under the aspect of heavy metal metabolism in human lymphocytes