On properties of principal elements of Frobenius Lie algebras

We investigate the properties of principal elements of Frobenius Lie algebras, following the work of M. Gerstenhaber and A. Giaquinto. We prove that any Lie algebra with a left symmetric algebra structure can be embedded, in a natural way, as a subalgebra of some sl(m,K), for K= R or C. Hence, the work of Belavin and Drinfeld on solutions of the Classical Yang-Baxter Equation on simple Lie algebras, applied to the particular case of sl(m, K) alone, paves the way to the complete classification of Frobenius and more generally quasi-Frobenius Lie algebras. We prove that, if a Frobenius Lie algebra has the property that every derivation is an inner derivation, then every principal element is semisimple, at least for K=C. As an important case, we prove that in the Lie algebra of the group of affine motions of the Euclidean space of finite dimension, every derivation is inner. We also bring a class of examples of Frobenius Lie algebras, that hence are subalgebras of sl(m, K), but yet have nonsemisimple principal elements as well as some with semisimple principal elements having nonrational eigenvalues, where K=R or C.Comment: Latex, 16 pages. The last version appeared at Journal of Lie Theory. Keywords and phrases: Frobenius Lie algebra, affine Lie algebra, Left symmetric Lie algebra, affine motion, symplectic Lie algebra, seaweed Lie algebra, symplectic Lie group, invariant symplectic structure, invariant affine structur

The Development of a Temporal Information Dictionary for Social Media Analytics

Dictionaries have been used to analyze text even before the emergence of social media and the use of dictionaries for sentiment analysis there. While dictionaries have been used to understand the tonality of text, so far it has not been possible to automatically detect if the tonality refers to the present, past, or future. In this research, we develop a dictionary containing time-indicating words in a wordlist (T-wordlist). To test how the dictionary performs, we apply our T-wordlist on different disaster related social media datasets. Subsequently we will validate the wordlist and results by a manual content analysis. So far, in this research-in-progress, we were able to develop a first dictionary and will also provide some initial insight into the performance of our wordlist

Challenging Cassandra: Household and Per Capita Household Income Distribution in the October Household Surveys 1995-1999, Income and Expenditure Surveys 1995 & 2000, and the Labour Force Survey 2000

This paper examines household income inequality in the South African October Household Survey datasets between 1995 and 1999, the Labour Force Survey 2000, and the Income and Expenditure Surveys 1995 and 2000. The paper reflects both on changing patterns of income inequality in South Africa, and on the quality and comparability of the data employed. We employ several measures of income inequality, employing nominal income and expenditure data from South Africa over the 1995-2000 period. Results prove sensitive to the choice of welfare measure. Furthermore, results from income data and expenditure data provide contrasting results. On self-reported income data, our findings are that inequality measures increased over the 1995 - 2000 time period. While we do not attach much credence to the evidence for reasons attaching to data quality, there is nevertheless evidence suggesting that the general increase in inequality for the African race group also hides a decrease in inequality for the bottom 1/3 of the income distribution, and (more unambiguously) a widening of inequality for the middle 1/3 of the income distribution for Africans. There is also some evidence of a narrowing inequality amongst rich households for the population as a whole. This suggests that there is at least some evidence consistent with a successful redistribution of income from richest to poorest households, though this has not yet reversed the high aggregate level of inequality in South Africa. Evidence from inequality measures based on expenditure data reverse the findings based on self-reported income. Where there is evidence of an increase in inequality, in most instances this proves to be statistically insignificant. On some measures African as well as total population inequality has declined significantly, and for a number of racial groups inequality has remained unchanged. The central conclusion of the paper is therefore that there is much contradictory evidence that emerges from household level data on income inequality - suggesting that the choice of data set is non-trivial in drawing inference on income inequality in South Africa

Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidase-based pyrethroid tolerance

BACKGROUND: Insecticide-treated nets (ITNs) are an integral component of malaria control programmes in Africa. How much pyrethroid resistance in malaria vectors will impact on the efficacy of ITNs is controversial. The purpose of this study was to evaluate knockdown and killing effects of ITNs on a metabolic-based resistant or tolerant malaria vector strain. METHODS: Bio-efficacy of 500 mg/m(2 )permethrin EC treated bednets was assessed on the OCEAC laboratory (OC-Lab) strain of Anopheles gambiae s.s.. This strain is resistant to DDT and tolerant to pyrethroids, with elevated mixed function oxidases. The Kisumu reference susceptible strain of A. gambiae s.s. was used as control. Nets were impregnated in February 1998 and used by households of the Ebogo village. Then they were collected monthly over six months for Bio-assays (WHO cone test). Knockdown and mortality rates were compared between the OC-Lab and the Kisumu strains, by means of the Mantel-Haenszel chi-square test. RESULTS: During the whole trial, permethrin EC knockdown rates were impressive (mostly higher than 97%). No significant difference was observed between the two strains. However, the mortality rates were significantly decreased in the OC-Lab strain (40–80%) compared with that of the Kisumu strain (75–100%). The decrease of killing effect on the OC-Lab strain was attributed to permethrin EC tolerance, due to the high oxidase metabolic activity. CONCLUSION: These data suggested an impact of pyrethroid tolerance on the residual activity of ITNs. More attention should be given to early detection of resistance using biochemical or molecular assays for better resistance management

Camera stereo-pair for object tracking in 3D

První část se zabývá návrhem jednoduchého systému značek, který by umožnil sledování polohy objektu v prostoru. Je zde popsán způsob návrhu systému značek a jejich vlastnosti jsou zhodnoceny v několika testech. Druhá část práce je věnována stručnému úvodu do problematiky stereovidění a výpočtům prostorových souřadnic objektu. Dále je zde popsána výsledná aplikace pro sledování trajektorie předmětů. Nakonec je provedeno měření opakovatelnosti výsledků.The first part deals with a design of simple pattern system that would allow tracking position of the object in space. There is described design of patterns and their properties are evaluated in several tests. The second part is devoted to a brief introduction on stereovision and calculation of the spatial coordinates of the object. Furthermore, there is described the resulting application for object tracking. Finally, is done repeabillity measure test.

Identifying and Overcoming the Factors Limiting Growth and Substrate Utilization in \u3ci\u3eCaldicellulosiruptor bescii\u3c/i\u3e

Caldicellulosiruptor bescii is an anaerobic extreme thermophile being studied for production of lignocellulosic biofuels due to its potential for plant biomass deconstruction. It can grow on a wide range of substrates and co-metabolize C5 and C6 sugars. However, incomplete biomass utilization and low cell growth, among other bottlenecks, majorly limit its bioconversion potential. The work in this dissertation aimed at identifying and overcoming the factors that hinder growth and substrate utilization in C. bescii and focused on low pH and high osmolarity as the investigated conditions that may serve as inhibitors. An RNA-seq data analysis pipeline was developed using a Bacillus thuringiensis data-set that determined essential parameters such as required number of reads and replicates for achieving results with high statistical confidence. This was further used for examining the physiological and systems level responses of C. bescii to acidic pH using integrated omics. In this study, lowering pH from 7.2 to 6.0 in mid-log and post stationary growth phases demonstrated lowered membrane potential/proton motive force (PMF) as a cause of these limitations. Dramatic increase in growth, improved substrate utilization and higher product generation was observed upon alleviating the PMF limitations post-acid addition. Patterns of elevated membrane potential and higher ATP pools further supported the hypothesis. In a follow-up study using liquid and crystalline cellulose it was demonstrated that C. bescii also benefits from the lowered pH on solid substrates indicating PMF limitation exists irrespective of the substrate and alleviation of the limitation under lower pH improves growth. Moreover, this study revealed osmolarity as the next immediate factor limiting the bioconversion potential of C. bescii once PMF limitation is alleviated. The ability of C. bescii to maintain growth at pH 5.5 (0.1 hr-1 dilution rate) in chemostat on Avicel was also displayed here which has not been previously reported, extending its growth pH range (5.5-7.3). Finally, an attempt to expand the genetic tools available for C. bescii was made, exploring RNA interference (RNAi) technology as a basis for developing a genome-wide screening tool in the future, which would aid to identify genetic elements that could confer robustness under various stress conditions