PERFORMANCE ANALYSIS OF DUAL-BRANCH SELECTION DIVERSITY SYSTEM USING NOVEL MATHEMATICAL APPROACH

In this paper, novel mathematical approach for evaluation of probability density function (PDF) of instantaneous signal-to-interference ratio (SIR) at the receiver output in interference-limited environment is proposed. Dual-branch selection combining (SC) receiver operating over correlated Weibull fading channels applying SIR algorithm is considered. Analytical expression for joint PDF of desired signal and interference at the receiver output is derived and used for evaluation of PDF of instantaneous SIR. The expression for PDF of SIR is used for system performance analysis via outage probability, average bit error probability (ABEP) and average output SIR as system performance measures. Numerical results are graphically presented showing the effects of fading severity, average SIR at the input and level of correlation on the diversity receiver performance. In addition, results obtained for the PDF of instantaneous SIR in this paper, are compared to the results when the PDF of instantaneous SIR is directly calculated

Performance analysis of dual-branch selection diversity receiver that uses desired signal algorithm in correlated Weibull fading environment

Rad je usmjeren na analizu karakteristika višestrukog sustava selektivnog kombiniranja (SC) s dvije grane gdje su i interferencija željenog signala i ko-kanalna interferencija (CCI) izložene Weibull fedingu. Za slučaj kada se algoritam željenog signala rabi kao kriterij za donošenje odluke izvedeni su izrazi zatvorenog oblika za zajedničku funkciju raspodjele vjerojatnosti (PDF) željenog signala i interferencije kao i PDF za trenutačni odnos signal-interferencija (SIR) na izlazu sustava. Ovi se izrazi rabe za analizu karakteristika cijeloga sustava rabeći vjerojatnost otkaza sustava, prosječnu vjerojatnost greške bita (ABEP) i prosječni izlaz SIR kao mjere za karakteristike sustava. Konačno, rezultati dobiveni u ovom radu uspoređeni su s ranije objavljenim rezultatima za isti sustav koji rabi algoritam na bazi SIR-a.This paper focuses on performance analysis of dual-branch selection combining (SC) diversity system where both, desired signal as well as co-channel interference (CCI), are subjected to Weibull fading. For the case when desired signal algorithm is used as decision criterion, closed form expressions for joint probability density function (PDF) of desired signal and interference as well as PDF for instantaneous signal-to-interference ratio (SIR) at the system output are derived. These expressions are used for overall system performance analysis using outage probability, average bit error probability (ABEP) and average output SIR as system performance measures. Finally, the results obtained in this paper are compared to the previously published results for the same system that uses SIR based algorithm

Značaj leguminoza za organsku poljoprivredu

Legume crops are primarily grown for their quality and value-added traits. Apart from their role in human and animal nutrition, they are being increasingly used as medicinal plants in pharmaceutical production. Legumes are of great interest in cultural practices under all farming systems, particularly organic agriculture. They are essential in crop rotations, and are among the most desirable preceding crops that create favourable biophysical conditions within the soil, with high levels of nitrogen naturally accumulating. There are many legumes suitable for companion and cover crops, and in the absence of quality farmyard manure they are sown for green manuring. In organic farming, legumes are environmental corridor components involved in biodiversity protection and restoration, as evidenced through increasing numbers of beneficial species in these isolation belts.Leguminoze su grupa biljaka koje se prvenstveno gaje zbog njihovog kvaliteta i velike upotrebne vrednosti. Osim za ishranu ljudi i domaćih životinja, sve više se koriste i kao lekovite biljke za proizvodnju različitih farmaceutskih preparata. Leguminoze imaju izuzetan agrotehnički značaj u svim sistemima poljoprivredne proizvodnje, a posebno u organskoj poljoprivredi. U plodoredu su nezamenjive kao jedan od najpoželjnijih preduseva, koji zemljište ostavlja u povoljnom biofizičkom stanju, sa visokim sadržajem na prirodan način akumuliranog azota. Veliki broj leguminoza je dobar za gajenje u združenim i pokrovnim usevima, a u nedostatku kvalitetnog stajskog đubriva, seju se kao siderati. U organskoj poljoprivredi mahunarke su sastavni deo eko-koridora koji imaju ulogu da zaštite i obnavljaju biodiverzitet, što se manifestije povećanjem broja korisnih vrsta u ovim izolacionim pojasevima

Endocytosis and lysosomal degradation of GluA2/3 AMPARs in response to oxygen/glucose deprivation in hippocampal but not cortical neurons

Abstract Global cerebral ischemia results in oxygen and glucose deprivation (OGD) and consequent delayed cell death of vulnerable neurons, with hippocampal CA1 neurons more vulnerable than cortical neurons. Most AMPA receptors (AMPARs) are heteromeric complexes of subunits GluA1/GluA2 or GluA2/GluA3, and the presence of GluA2 renders AMPARs Ca2+-impermeable. In hippocampal CA1 neurons, OGD causes the synaptic expression of GluA2-lacking Ca2+-permeable AMPARs, contributing to toxic Ca2+ influx. The loss of synaptic GluA2 is caused by rapid trafficking of GluA2-containing AMPARs from the cell surface, followed by a delayed reduction in GluA2 mRNA expression. We show here that OGD causes endocytosis, lysosomal targeting and consequent degradation of GluA2- and GluA3-containing AMPARs, and that PICK1 is required for both OGD-induced GluA2 endocytosis and lysosomal sorting. Our results further suggest that GluA1-containing AMPARs resist OGD-induced endocytosis. OGD does not cause GluA2 endocytosis in cortical neurons, and we show that PICK1 binding to the endocytic adaptor AP2 is enhanced by OGD in hippocampal, but not cortical neurons. We propose that endocytosis of GluA2/3, caused by a hippocampal-specific increase in PICK1-AP2 interactions, followed by PICK1-dependent lysosomal targeting, are critical events in determining changes in AMPAR subunit composition in the response to ischaemia

Trend of suicide by self-immolation in a 13-year timeline: was the COVID-19 pandemic a potentially important stressor?

IntroductionSelf-immolation is an uncommon way of attempting and committing a suicide, with a fatality rate of 80%. The risk factors in self-immolation victims vary depending on demographic characteristics, socio-economic and cultural factors as well as religious beliefs. Whether the COVID-19 pandemic was a potentially important stressor for self-immolation is still unknown, with insufficient studies examining this issue. Therefore, in this study, we aimed to examine the trend of self-immolation in a 13-year timeline, and the potential association of COVID-19 pandemic with the increase in the incidence and severity of self-immolation injuries in Serbia in 2021.Materials and methodsThe study included hospitalized patients due to intentional burns caused by self-immolation in the period from January 1, 2008 to December 31, 2021. Joinpoint regression analysis was used for the analysis of continuous linear trends of self-immolation cases with change points.ResultsWhile a rising trend was observed in the 2008–2013 time segment, followed by a decline in the upcoming 2013–2016 time segment, a significant increase reached its maximum during COVID-19 pandemic (2021), with annual percent change of 37.1% (p = 0.001). A significant increase in the median number of cases per year was observed during 2021 compared to the previous periods (7.5 vs. 2). Frequency of patients with a psychiatric diagnosis vs. those without a psychiatric diagnosis was significantly higher during than before the COVID-19 period (66.7 vs. 36.1%, p = 0.046).ConclusionIn our study, a significant increase in the frequency of suicide attempts by self-immolation during COVID-19 pandemic was noticed. There was also an increased frequency of pre-existing psychiatric illness among patients during the pandemic period. With limited high-quality data available, the study adds to a rising body of evidence for assessment of outcomes of the pandemic on mental health and recognition of stressors for self-immolation

CD81 extracted in SMALP nanodiscs comprises two distinct protein populations within a lipid environment enriched with negatively charged headgroups

Tetraspanins exert a wide range of cellular functions of broad medical importance. Despite this, their biophysical characteristics are incompletely understood. Only two high-resolution structures of full-length tetraspanins have been solved. One is that of human CD81, which is involved in the infectivity of human pathogens including influenza, HIV, the malarial plasmodium parasite and hepatitis C virus (HCV). The CD81 crystal structure identifies a cholesterol-binding pocket, which has been suggested to be important in the regulation of tetraspanin function. Here we investigate the use of styrene-maleic anhydride co-polymers (SMA) for the solubilisation and purification of CD81 within a lipid environment. When CD81 was expressed in the yeast Pichia pastoris, it could be solubilised and purified using SMA2000. This SMALP-encapsulated CD81 retained its native folded structure, as determined by the binding of two conformation-sensitive anti-CD81 antibodies. Analysis by size exclusion chromatography revealed two distinct populations of CD81, only one of which bound the HCV glycoprotein, E2. Optimization of expression and buffer conditions increased the proportion of E2-binding competent CD81 protein. Mass spectrometry analysis indicated that the lipid environment surrounding CD81 is enriched with negatively charged lipids. These results establish a platform to study the influence of protein-lipid interactions in tetraspanin biology

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements