Fluorescence spectroscopy for characterization and differentiation of beers

Total luminescence and synchronous scanning fluorescence spectroscopic techniques were applied for characterization of the intrinsic fluorescence of eight different beers. Spectra were measured using different geometries to reveal the presence of similar fluorescent components. The total luminescence and synchronous fluorescence spectra exhibit a relatively intense short-wavelength emission ascribed to aromatic amino acids and less intense emission in the long-wavelength region, which may originate from B vitamins. Classification of beers based on their synchronous fluorescence spectra was performed using non-parametrical k nearest neighbours method and linear discriminant analysis. Very good discrimination was obtained in both methods with a low classification error. The results demonstrate the potential of fluorescence techniques to characterize and differentiate beers

Influence of hereditary haemochromatosis on left ventricular wall thickness: does iron overload exacerbate cardiac hypertrophy?

Background: The left ventricular (LV) hypertrophy increases the risk of heart failure. Hypertension and infiltrative cardiomyopathies are the well-known reasons of LV hypertrophy. The growing interest of scientists in this issue affects hereditary haemochromatosis (HH), which is characterised by the excess deposition of iron mostly due to HFE gene mutation. The aim of our study was to investigate the possible influence of HH on LV parameters in patients with early-diagnosed (early HH) and long-lasting and long-treated (old HH) disease. Materials and methods: Thirty nine early HH and 19 old HH patients were prospectively enrolled in the study; age- and sex-matched healthy volunteers constituted the appropriate control groups. All participants had echocardiography performed (including three-dimension volume and mass analysis); the iron turnover parameters were measured at the time of enrolment in every HH patients. Results: Echocardiographic parameters regarding to left atrium (LA), LV thickness, mass and long axis length were significantly higher, whereas LV ejection fraction was lower in early HH in comparison to healthy persons. In old HH patients the differences were similar to those mentioned before, except LV ejection fraction. The presence of hypertension in both HH groups did not influence echo parameters, as well as diabetes in old HH. The strongest correlation in all HH group was found between the time from HH diagnosis and LA, LV thickness and volumes parameters, but the correlations between iron turnover and echo parameters were non-existent. Conclusions: Hereditary haemochromatosis, not only long-lasting, but also early-diagnosed, could lead to exacerbation of LV wall thickness and cardiac hypertrophy. This effect is not simply connected with hypertension and diabetes that are frequent additional diseases in these patients, but with the time from HH diagnosis

Thus far but no further: predatory mites do not migrate effectively into strawberry plantations

Enhancing the performance of predatory mites is often regarded as the best biological control approach towards the spider mite Tetranychus urticae, the main pest of strawberry plantations. Optimizing the colonization of plantations by predators from adjacent areas such as field margins is seen as an important component of conservation biocontrol. We have investigated the factors contributing to enhancing the numbers of predatory mites (Acari: Phytoseidae), such as management of the field margins, vegetation composition and the effect of the presence of woody species. We also tested the penetration of the phy-toseiids from the field margins into the crop. In a study carried out in 14 open-field exten-sively managed strawberry plantations in Poland we found phytoseiids to be abundant in field margins; 14 taxa were discovered. However, only two species Amblyseius andersoniand Euseius finlandicus dispersed a modest distance into the crop. We found that the diver-sity and densities of the predatory mites were enhanced somewhat by the management type of the field margins; especially the spontaneous vegetation favoured the presence of phyto-seiids. However, despite the predatory mites being rather retained in the field margins also significant reduction in numbers of their prey T. urticae was recorded over the course of the year. The low penetration of predatory mites into the main part of the field, indicates that conservation biological control measures in the field margin might not be sufficient on their own to enhance the impact of predatory mites within the main part of the fields

Screening of antioxidant properties of the apple juice using the front-face synchronous fluorescence and chemometrics

Fluorescence spectroscopy is gaining increasing attention in food analysis due to its higher sensitivity and selectivity as compared to other spectroscopic techniques. Synchronous scanning fluorescence technique is particularly useful in studies of multi-fluorophoric food samples, providing a further improvement of selectivity by reduction in the spectral overlapping and suppressing light-scattering interferences. Presently, we study the feasibility of the prediction of the total phenolics, flavonoids, and antioxidant capacity using front-face synchronous fluorescence spectra of apple juices. Commercial apple juices from different product ranges were studied. Principal component analysis (PCA) applied to the unfolded synchronous fluorescence spectra was used to compare the fluorescence of the entire sample set. The regression analysis was performed using partial least squares (PLS1 and PLS2) methods on the unfolded total synchronous and on the single-offset synchronous fluorescence spectra. The best calibration models for all of the studied parameters were obtained using the PLS1 method for the single-offset synchronous spectra. The models for the prediction of the total flavonoid content had the best performance; the optimal model was obtained for the analysis of the synchronous fluorescence spectra at Delta lambda = 110 nm (R (2) = 0.870, residual predictive deviation (RPD) = 2.7). The optimal calibration models for the prediction of the total phenolic content (Delta lambda = 80 nm, R (2) = 0.766, RPD = 2.0) and the total antioxidant capacity (Delta lambda = 70 nm, R (2) = 0.787, RPD = 2.1) had only an approximate predictive ability. These results demonstrate that synchronous fluorescence could be a useful tool in fast semi-quantitative screening for the antioxidant properties of the apple juices.info:eu-repo/semantics/publishedVersio

Large-scale expression analysis reveals distinct microRNA profiles at different stages of human neurodevelopment

Background: MicroRNAs (miRNAs) are short non-coding RNAs predicted to regulate one third of protein coding genes via mRNA targeting. In conjunction with key transcription factors, such as the repressor REST (RE1 silencing transcription factor), miRNAs play crucial roles in neurogenesis, which requires a highly orchestrated program of gene expression to ensure the appropriate development and function of diverse neural cell types. Whilst previous studies have highlighted select groups of miRNAs during neural development, there remains a need for amenable models in which miRNA expression and function can be analyzed over the duration of neurogenesis. Principal Findings: We performed large-scale expression profiling of miRNAs in human NTera2/D1 (NT2) cells during retinoic acid (RA)-induced transition from progenitors to fully differentiated neural phenotypes. Our results revealed dynamic changes of miRNA patterns, resulting in distinct miRNA subsets th

Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

Set-valued orthogonal additivity

We study the set-valued Cauchy equation postulated for orthogonal vectors. We give its general solution as well as we look for selections of functions satisfying the equation

Orthogonalities and functional equations

In this survey we show how various notions of orthogonality appear in the theory of functional equations. After introducing some orthogonality relations, we give examples of functional equations postulated for orthogonal vectors only. We show their solutions as well as some applications. Then we discuss the problem of stability of some of them considering various aspects of the problem. In the sequel, we mention the orthogonality equation and the problem of preserving orthogonality. Last, but not least, in addition to presenting results, we state some open problems concerning these topics. Taking into account the big amount of results concerning functional equations postulated for orthogonal vectors which have appeared in the literature during the last decades, we restrict ourselves to the most classical equations