An output-sensitive algorithm for the minimization of 2-dimensional String Covers

String covers are a powerful tool for analyzing the quasi-periodicity of 1-dimensional data and find applications in automata theory, computational biology, coding and the analysis of transactional data. A \emph{cover} of a string $T$ is a string $C$ for which every letter of $T$ lies within some occurrence of $C$. String covers have been generalized in many ways, leading to \emph{k-covers}, \emph{$\lambda$-covers}, \emph{approximate covers} and were studied in different contexts such as \emph{indeterminate strings}. In this paper we generalize string covers to the context of 2-dimensional data, such as images. We show how they can be used for the extraction of textures from images and identification of primitive cells in lattice data. This has interesting applications in image compression, procedural terrain generation and crystallography

A new approach to in silico SNP detection and some new SNPs in the Bacillus anthracis genome

<p>Abstract</p> <p>Background</p> <p><it>Bacillus anthracis </it>is one of the most monomorphic pathogens known. Identification of polymorphisms in its genome is essential for taxonomic classification, for determination of recent evolutionary changes, and for evaluation of pathogenic potency.</p> <p>Findings</p> <p>In this work three strains of the <it>Bacillus anthracis </it>genome are compared and previously unpublished single nucleotide polymorphisms (SNPs) are revealed. Moreover, it is shown that, despite the highly monomorphic nature of <it>Bacillus anthracis</it>, the SNPs are (1) abundant in the genome and (2) distributed relatively uniformly across the sequence.</p> <p>Conclusions</p> <p>The findings support the proposition that SNPs, together with indels and variable number tandem repeats (VNTRs), can be used effectively not only for the differentiation of perfect strain data, but also for the comparison of moderately incomplete, noisy and, in some cases, unknown <it>Bacillus anthracis </it>strains. In the case when the data is of still lower quality, a new DNA sequence fingerprinting approach based on recently introduced markers, based on combinatorial-analytic concepts and called cyclic difference sets, can be used.</p

Attribution of divergent northern vegetation growth responses to lengthening non-frozen seasons using satellite optical-NIR and microwave remote sensing

The non-frozen (NF) season duration strongly influences the northern carbon cycle where frozen (FR) temperatures are a major constraint to biological processes. The landscape freeze-thaw (FT) signal from satellite microwave remote sensing provides a surrogate measure of FR temperature constraints to ecosystem productivity, trace gas exchange, and surface water mobility. We analysed a new global satellite data record of daily landscape FT dynamics derived from temporal classification of overlapping SMMR and SSM/I 37 GHz frequency brightness temperatures (Tb). The FT record was used to quantify regional patterns, annual variability, and trends in the NF season over northern (≥45°N) vegetated land areas. The ecological significance of these changes was evaluated against satellite normalized difference vegetation index (NDVI) anomalies, estimated moisture and temperature constraints to productivity determined from meteorological reanalysis, and atmospheric CO2 records. The FT record shows a lengthening (2.4 days decade-1; p &lt; 0.005) mean annual NF season trend (1979-2010) for the high northern latitudes that is 26% larger than the Northern Hemisphere trend. The NDVI summer growth response to these changes is spatially complex and coincides with local dominance of cold temperature or moisture constraints to productivity. Longer NF seasons are predominantly enhancing productivity in cold temperature-constrained areas, whereas these effects are reduced or reversed in more moisture-constrained areas. Longer NF seasons also increase the atmospheric CO2 seasonal amplitude by enhancing both regional carbon uptake and emissions. We find that cold temperature constraints to northern growing seasons are relaxing, whereas potential benefits for productivity and carbon sink activity are becoming more dependent on the terrestrial water balance and supply of plant-available moisture needed to meet additional water use demands under a warming climate. © 2014 Taylor &amp; Francis

The dynamic and thermodynamic structure of the monsoon over southern India: new observations from the INCOMPASS IOP

Some of the highest summer monsoon rainfall in South Asia falls on the windward slopes of the Western Ghats mountains on India’s west coast and offshore over the eastern Arabian Sea. Understanding of the processes determining the spatial distribution and temporal variability of this region remains incomplete. In this paper, new Interaction of Convective Organization and Monsoon Precipitation, Atmosphere, Surface and Sea (INCOMPASS) aircraft and ground-based measurements of the summer monsoon over the Western Ghats and upstream of them are presented and placed within the context of remote sensing observations and reanalysis. The transition from widespread rainfall over the eastern Arabian Sea to rainfall over the Western Ghats is documented in high spatial and temporal resolution. Heavy rainfall offshore during the campaign was associated primarily with mid-tropospheric humidity, secondarily with sea surface temperature, and only weakly with orographic blocking. A mid-tropospheric dry intrusion suppressed deep convection offshore in the latter half of the campaign, allowing the build-up of low-level humidity in the onshore flow and enhancing rainfall over the mountains. Rainfall on the lee side of the Western Ghats occurred during the latter half of the campaign in association with enhanced mesoscale easterly upslope flow. Diurnal cycles in rainfall offshore (maximum in the morning) and on the mountains (maximum in the afternoon) were observed. Considerable zonal and temporal variability was seen in the offshore boundary layer, suggesting the presence of convective downdrafts and cold pools. Persistent drying of the subcloud mixed layer several hundred kilometres off the coast was observed, suggesting strong mixing between the boundary layer and the free troposphere. These observations provide quantitative targets to test models and suggest hypotheses on the physical mechanisms determining the distribution and variability in rainfall in the Western Ghats region

Elemental analysis as an important tool for fuels and biofuels quality control

Article presents normalized analytical methods for determination of elements in fuels and biofuels with emphasis on inductively coupled plasma emission spectrometry (ICP-OES) and their advantages and disadvantages. Analytical procedure applied for determination of 20 elements (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Si, Sn, Ti, V and Zn) is described with elements of validation. Broad range of elemental analysis results of fuels (B0, B7 and B10) and pure FAME samples are described. Typical contents of selected elements are presented which allows discussion on the domestic fuel quality in regard to non-standardized parameters and their potential effect on combustion engines performance

In-vehicle air quality : recent trends in requirements and testing methods

W artykule omówiony został problem jakości powietrza wewnętrznego w kabinach samochodów osobowych. Problematykę przedstawiono w oparciu o dyskusję zjawisk istotnie wpływających na zanieczyszczenie powietrza wewnątrz, głównie nowych, samochodów, metod badawczych stosowanych w motoryzacji w celu oceny obecności tych zanieczyszczeń, a także wskazywania i eliminacji ich źródeł. Podkreślono istotne różnice w działaniach zmierzających do poprawy jakości powietrza we wnętrzach nowych samochodów wprowadzanych na rynek, podejmowanych przez producentów i/lub wymaganych przepisami prawnymi.In-vehicle air quality in passengers’ cars is discussed in present paper. The discussion is based on factors influencing substantially interior air pollution in vehicles, mainly new ones, on test methods used in automotive sector for air quality assessment, and for elimination of pollution sources. Various approaches to control and to improve in-vehicle air quality was presented with regard to probable directions applied by the automotive industry

The influence of sample preparation on elements contents determination in engine oils

W artykule omówiono właściwości i zakres badań olejów silnikowych. Omówiono źródła pochodzenia pierwiastków w olejach oraz przedstawiono znormalizowane metody oznaczania zawartości pierwiastków. Przywołane metody różnią się zakresem oznaczanych pierwiastków i zakresem oznaczanych stężeń. Omówiono sposób przygotowania próbki do pomiaru metodą spektrometrii emisyjnej z plazmą indukcyjnie sprzężoną (ICP-OES). Metodę ICP-OES wykorzystano do badania zawartości pierwiastków w świeżych i eksploatowanych olejach silnikowych. Porównano wyniki uzyskane dla próbek olejów poddanych mineralizacji na mokro w zamkniętym systemie wspomaganym mikrofalami oraz dla próbek po rozcieńczeniu rozpuszczalnikiem organicznym. Przedstawiono elementy walidacji metody badawczej oraz wyniki badania zawartości 21 pierwiastków (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Si, Sn, Ti, V i Zn) w olejach silnikowych.In present paper properties of engine oils and range of oil analysis are discussed. Sources of elements in oil and normalized test methods of elements determination are presented. Mentioned methods differ in the range of determined elements and range of their concentrations. The method of sample preparation to subsequent analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) is described. ICP-OES method was used to analysis of elements contents in fresh and used engine oils. The results obtained for samples after wet mineralization in closed microwaveassisted system and for samples diluted with organic solvent are compared. Test method validation and results of analysis of 21 elements (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Si, Sn, Ti, V and Zn) in engine oils are presented