609 research outputs found

    The Distribution of Minimum of Ratios of Two Random Variables and Its Application in Analysis of Multi-hop Systems

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    The distributions of random variables are of interest in many areas of science. In this paper, ascertaining on the importance of multi-hop transmission in contemporary wireless communications systems operating over fading channels in the presence of cochannel interference, the probability density functions (PDFs) of minimum of arbitrary number of ratios of Rayleigh, Rician, Nakagami-m, Weibull and α-µ random variables are derived. These expressions can be used to study the outage probability as an important multi-hop system performance measure. Various numerical results complement the proposed mathematical analysis

    Exploring the role of university education in reducing the appeal of right‐wing populism

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    First published: 02 October 2023. OnlinePublWhy are university‐educated ethnic majority men less likely to support right‐wing populism (RWP) than those without university education? To investigate this under‐researched question, we conducted an exploratory study using semistructured interviews and thematic analysis with white Australian men from different socioeconomic backgrounds. While some with university education supported RWP, their views aligned with a moderate version of the ideology. Student/graduate supporters of RWP were opposed to hiring practices designed to support gender and ethnic equity. Students/graduates who experienced contact with Others were generally more positive about diversity, but this was not always the case for non‐university participants. While students/graduates with RWP leanings tended to see university as a politically biased institution, concerns about political correctness were widespread across the sample. Significantly, numerous students/graduates experienced university education as promoting a pluralist outlook, and this outlook appears fundamentally incompatible with the monist tendencies of RWP ideology. However, findings also suggest that university education is not the only route to a pluralist outlook, nor does it always lead to a rejection of RWP. Hence, developing a pluralist outlook may be more important than university education in reducing the appeal of RWP. The implications of these exploratory findings for future research are discussed.Nathan Manning, Djordje Stefanovi

    Genetic, enzymatic and metabolite profiling of the Lactobacillus casei group reveals strain biodiversity and potential applications for flavour diversification

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    Aims: The Lactobacillus casei group represents a widely explored group of lactic acid bacteria, characterized by a high level of biodiversity. In this study, the genetic and phenotypic diversity of a collection of more than 300 isolates of the Lact. casei group and their potential to produce volatile metabolites important for flavour development in dairy products, was examined. Methods and Results: Following confirmation of species by 16S rRNA PCR, the diversity of the isolates was determined by pulsed-field gel electrophoresis. The activities of enzymes involved in the proteolytic cascade were assessed and significant differences among the strains were observed. Ten strains were chosen based on the results of their enzymes activities and they were analysed for their ability to produce volatiles in media with increased concentrations of a representative aromatic, branched chain and sulphur amino acid. Volatiles were assessed using gas chromatography coupled with mass spectrometry. Strain-dependent differences in the range and type of volatiles produced were evident. Conclusions: Strains of the Lact. casei group are characterized by genetic and metabolic diversity which supports variability in volatile production. Significance and Impact of the Study: This study provides a screening approach for the knowledge-based selection of strains potentially enabling flavour diversification in fermented dairy products

    Topical Corticosteroids Normalize both Skin and Systemic Inflammatory Markers in Infant Atopic Dermatitis

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    Background: Atopic dermatitis (AD) is the most common inflammatory skin disease. It is highly heterogeneous in clinical presentation, treatment response, disease trajectory and associated atopic comorbidities. Immune biomarkers are dysregulated in skin and peripheral blood. Aims: We used noninvasive skin and peripheral biomarkers to observe the effects of real-world topical corticosteroid (TCS) treatment in infants with AD, by measuring skin and blood biomarkers before and after therapy. Methods: Seventy-four treatment-naïve infants with AD underwent 6 weeks of TCS treatment. Stratum corneum (SC) and plasma blood biomarkers as well as SC natural moisturizing factor (NMF) were measured before and after TCS therapy. Immune markers included innate, T helper (Th)1 and Th2 immunity, angiogenesis, and vascular factors. AD severity was assessed by the Scoring Atopic Dermatitis index, and skin barrier function by transepidermal water loss (TEWL). Twenty healthy infants were recruited as controls. Results: TCS therapy predictably led to improvement in disease severity. Levels of immune markers in the skin and in the peripheral blood showed significant change from baseline, though most did not reach healthy control levels. The most prominent change from baseline in the SC was in markers of innate immune activation, interleukin (IL)-18, IL-8 and IL-1α, and the Th2 chemokines C-C motif chemokine (CCL)17 and CCL22. In blood, the largest changes were in Th2-skewed biomarkers: CCL17, IL-13, CCL22, IL-5, and CCL26. TEWL decreased after therapy; no significant changes from baseline were found for NMF. Conclusions: The profound impact of topical therapy on systemic biomarkers suggests that the skin compartment generates a major component of dysregulated systemic cytokines in infant AD. There may be long-term beneficial effects of correcting systemic immune dysregulation through topical therapy

    Antimicrobial treatment of Corynebacterium striatum invasive infections: a systematic review

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    The aim of this study was to establish an evidence-based guideline for the antibiotic treatment of Corynebacterium striatum infections. Several electronic databases were systematically searched for clinical trials, observational studies or individual cases on patients of any age and gender with systemic inflammatory response syndrome, harboring C. striatum isolated from body fluids or tissues in which it is not normally present. C. striatum had to be identified as the only causative agent of the invasive infection, and its isolation from blood, body fluids or tissues had to be confirmed by one of the more advanced diagnostic methods (biochemical methods, mass spectrometry and/or gene sequencing). This systematic review included 42 studies that analyzed 85 individual cases with various invasive infections caused by C. striatum. More than one isolate of C. striatum exhibited 100% susceptibility to vancomycin, linezolid, teicoplanin, piperacillin-tazobactam, amoxicillin-clavulanate and cefuroxime. On the other hand, some strains of this bacterium showed a high degree of resistance to fluoroquinolones, to the majority majority of β-lactams, aminoglycosides, macrolides, lincosamides and cotrimoxazole. Despite the antibiotic treatment, fatal outcomes were reported in almost 20% of the patients included in this study. Gene sequencing methods should be the gold standard for the identification of C. striatum, while MALDI-TOF and the Vitek system can be used as alternative methods. Vancomycin should be used as the antibiotic of choice for the treatment of C. striatum infections, in monotherapy or in combination with piperacillin-tazobactam. Alternatively, linezolid, teicoplanin or daptomycin may be used in severe infections, while amoxicillin-clavulanate may be used to treat mild infections caused by C. striatum

    Evaluation of the Potential of Lactobacillus paracasei Adjuncts for Flavor Compounds Development and Diversification in Short-Aged Cheddar Cheese

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    peer-reviewedThe non-starter microbiota of Cheddar cheese mostly comprises mesophilic lactobacilli, such as Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Lactobacillus plantarum. These bacteria are recognized for their potential to improve Cheddar cheese flavor when used as adjunct cultures. In this study, three strains of L. paracasei (DPC2071, DPC4206, and DPC4536) were evaluated for their contribution to the enhancement and diversification of flavor in short-aged Cheddar cheese. The strains were selected based on their previously determined genomic diversity, variability in proteolytic enzyme activities and metabolic capability in cheese model systems. The addition of adjunct cultures did not affect the gross composition or levels of lipolysis of the cheeses. The levels of free amino acids (FAA) in cheeses showed a significant increase after 28 days of ripening. However, the concentrations of individual amino acids in the cheeses did not significantly differ except for some amino acids (aspartic acid, threonine, serine, and tryptophan) at Day 14. Volatile profile analysis revealed that the main compounds that differentiated the cheeses were of lipid origin, such as long chain aldehydes, acids, ketones, and lactones. This study demonstrated that the adjunct L. paracasei strains contributed to the development and diversification of compounds related to flavor in short-aged Cheddar cheeses

    Investigation of the neurovascular coupling in positive and negative BOLD responses in human brain at 7T

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    Decreases in stimulus-dependent blood oxygenation level dependent (BOLD) signal and their underlying neurovascular origins have recently gained considerable interest. In this study a multi-echo, BOLD-corrected vascular space occupancy (VASO) functional magnetic resonance imaging (fMRI) technique was used to investigate neurovascular responses during stimuli that elicit positive and negative BOLD responses in human brain at 7 T. Stimulus-induced BOLD, cerebral blood volume (CBV), and cerebral blood flow (CBF) changes were measured and analyzed in ‘arterial’ and ‘venous’ blood compartments in macro- and microvasculature. We found that the overall interplay of mean CBV, CBF and BOLD responses is similar for tasks inducing positive and negative BOLD responses. Some aspects of the neurovascular coupling however, such as the temporal response, cortical depth dependence, and the weighting between ‘arterial’ and ‘venous’ contributions, are significantly different for the different task conditions. Namely, while for excitatory tasks the BOLD response peaks at the cortical surface, and the CBV change is similar in cortex and pial vasculature, inhibitory tasks are associated with a maximum negative BOLD response in deeper layers, with CBV showing strong constriction of surface arteries and a faster return to baseline. The different interplays of CBV, CBF and BOLD during excitatory and inhibitory responses suggests different underlying hemodynamic mechanisms

    Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije

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    The subject of this paper was the examination of the influence of enzyme and substrate concentrations and temperature on the initial reaction rate of hydrolysis of the egg white catalyzed with Alcalase 2.4 L (Protease from Bacillus licheniformis). The main objective of this paper was investigating the effect of the ultrasound on the reaction rate of hydrolysis and modeling of enzymatic process of hydrolysis of the egg white protein in order to develop the process and design the enzyme reactor. The substrate in this reaction was 10 % w/w solution of egg white pretreated with ultrasound waves the frequency of 35 kHz during 30 min. Proper kinetic model with substrate inhibition and the enzyme inactivation were applied to the results and good congruence between model and experimental data was achieved. The calculated kinetic constants indicate that the ultrasonic pretreatment causes an increase in the degree of hydrolysis of the enzyme reaction.U ovom radu ispitivan je uticaj koncentacije enzima, supstrata i temperature na početnu brzinu reakcije hidrolize proteina belanceta katalizovane Alkalazom 2,4 L (proteaza iz Bacillus licheniformis). Glavni cilj ovog istraživanja bio je ispitivanje uticaja ultrazvučnih talasa na brzinu reakcije hidrolize, kao i modelovanje enzimskog procesa hidrolize proteina belanceta u cilju dobijanja projektnih jednačina neophodnih za projektovanje i dizajn enzimskog reaktora. Kao supstrat korišćen je 10 % w/w rastvor belanceta prethodno tretiran ultrazvučnim talasima frekvencije 35 kHz u toku 30 minuta. Dobijeni eksperimentalni rezultati modelovani su kinetičkim modelom koji uzima u obzir inhibiciju supstratom i deaktivaciju enzima. Predloženi kinetički model dao je dobro slaganje sa dobijenim eksperimentalnim rezultatima. Izračunate kinetičke konstante ukazuju da pretretman ultrazvučnim talasima dovodi do povećanja stepena hidrolize

    Molecular Spiders in One Dimension

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    Molecular spiders are synthetic bio-molecular systems which have "legs" made of short single-stranded segments of DNA. Spiders move on a surface covered with single-stranded DNA segments complementary to legs. Different mappings are established between various models of spiders and simple exclusion processes. For spiders with simple gait and varying number of legs we compute the diffusion coefficient; when the hopping is biased we also compute their velocity.Comment: 14 pages, 2 figure

    PERFORMANCE OF MACRO DIVERSITY WIRELESS COMMUNICATION SYSTEM OPERATING IN WEIBUL MULTIPATH FADING ENVIRONMENT

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    In this paper, we consider wireless mobile radio communication system with macro diversity reception. Signal is subject to Weibull small scale fading and Gamma large scale fading resulting in system performance degradation. Receiver uses macro diversity selection combining (SC) technique in order to reduce the impact of long term fading effects, and two micro diversity SC branches are used to mitigate Weibull short term fading effects on system performance. Probability density function (PDF), and cumulative distribution function (CDF), as well as level crossing rate (LCR) and average fade duration (AFD) of the SC receiver output signal envelope are evaluated. The obtained expressions converge rapidly for all considered values of Weibull fading parameter and Gamma shadowing severity parameter. Mathematical results are studied in order to analyze the influence of Weibull fading parameter and Gamma shadowing severity parameter on statistical properties of the SC receiver output signal
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