46 research outputs found

    The influence of induced mutagenesis on reproductive behavior of Drosophila subobscura and the role of sexual selection in relationto the level of mutational load

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    Prema teorijskim očekivanjima seksualna selekcija može smanjivati mutaciona opterećenja u populacijama. Mužjaci koji su boljeg genetičkog kvaliteta bi trebalo da budu uspešniji u parenju u poređenju sa mužjacima lošijeg genetičkog kvaliteta. Na taj način ženke, prilikom izbora partnera za parenje, mogu da eliminišu one mužjake koji nose štetne alele, i da smanje mogućnost prenošenja štetnih alela u sledeću generaciju. Seksualna selekcija će redukovati mutaciona opterećenja i povećavati adaptivnu vrednost populacije, ako je većina mutacija štetna i za adaptivnu vrednost i za osobine koje utiču na uspešnost mužjaka u parenju. Istraživanja poslednjih godina su dala rezultate koji idu u prilog ovoj teoriji, ali i oprečne rezultate. Ovakva kontradiktornost proizilazi iz kompleksnosti problematike usled različitih reproduktivnih strategija vrsta, kao i različitih reproduktivnih strategija mužjaka i ženki. Takođe, osobine koje utiču na komponente adaptivne vrednosti, kao i na uspešnost u parenju, su veoma složene, pod determinacijom velikog broja gena, i u čijoj osnovi leže kompleksne genske interakcije. Iako se kao osobine koje su cilj seksualne selekcije najčešće analiziraju sekundarne polne karakteristike, i mnoge druge osobine određuju atraktivnost mužjaka. To su i morfološke, fiziološke, ponašajne i druge osobine koje utiču na uspešnost u parenju, a mogu se nazvati osobinama koje su zavisne od opšteg stanja mužjaka (eng. condition-dependent traits)...According to theoretical predictions sexual selection can reduce mutational load in populations. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality. In this way females, through the choice of mating partners, can eliminate males carriers of deleterious alleles, and reduce transmission of deleterious alleles to the next generation. Sexual selection will purge mutational load and increase fitness if most mutations were deleterious to both nonsexual fitness and condition-dependent traits affecting mating success. Studies in recent years have yielded results that support this theory, but opposite results are obtained, as well. This contradiction arises from different reproductive strategies of species, and different reproductive strategies of males and females. Traits that affect fitness components, as well as mating success, are under polygenic determination, with very complex gene interactions. Although secondary sexual traits were usually analyzed as target of sexual selection, many other traits can determine male attractiveness. Traits such as morphological, physiological, behavior and other, affecting mating success, can be termed as condition-dependent traits. In order to test this hypothesis, that sexual selection can reduce mutational load, two experimental groups were formed from the same population genetic pool of Drosophila subobscura, which differed in the level of mutational load. Mutations were induced in one group, using 30Gy ionizing radiation. The effect of sexual selection in reduction of mutational load was measured through different components of male mating behavior (courtship occurrence, courtship latency, courtship intensity, mating occurrence,latency to mating and duration of mating)...

    The influence of induced mutagenesis on reproductive behavior of Drosophila subobscura and the role of sexual selection in relationto the level of mutational load

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    Prema teorijskim očekivanjima seksualna selekcija može smanjivati mutaciona opterećenja u populacijama. Mužjaci koji su boljeg genetičkog kvaliteta bi trebalo da budu uspešniji u parenju u poređenju sa mužjacima lošijeg genetičkog kvaliteta. Na taj način ženke, prilikom izbora partnera za parenje, mogu da eliminišu one mužjake koji nose štetne alele, i da smanje mogućnost prenošenja štetnih alela u sledeću generaciju. Seksualna selekcija će redukovati mutaciona opterećenja i povećavati adaptivnu vrednost populacije, ako je većina mutacija štetna i za adaptivnu vrednost i za osobine koje utiču na uspešnost mužjaka u parenju. Istraživanja poslednjih godina su dala rezultate koji idu u prilog ovoj teoriji, ali i oprečne rezultate. Ovakva kontradiktornost proizilazi iz kompleksnosti problematike usled različitih reproduktivnih strategija vrsta, kao i različitih reproduktivnih strategija mužjaka i ženki. Takođe, osobine koje utiču na komponente adaptivne vrednosti, kao i na uspešnost u parenju, su veoma složene, pod determinacijom velikog broja gena, i u čijoj osnovi leže kompleksne genske interakcije. Iako se kao osobine koje su cilj seksualne selekcije najčešće analiziraju sekundarne polne karakteristike, i mnoge druge osobine određuju atraktivnost mužjaka. To su i morfološke, fiziološke, ponašajne i druge osobine koje utiču na uspešnost u parenju, a mogu se nazvati osobinama koje su zavisne od opšteg stanja mužjaka (eng. condition-dependent traits)...According to theoretical predictions sexual selection can reduce mutational load in populations. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality. In this way females, through the choice of mating partners, can eliminate males carriers of deleterious alleles, and reduce transmission of deleterious alleles to the next generation. Sexual selection will purge mutational load and increase fitness if most mutations were deleterious to both nonsexual fitness and condition-dependent traits affecting mating success. Studies in recent years have yielded results that support this theory, but opposite results are obtained, as well. This contradiction arises from different reproductive strategies of species, and different reproductive strategies of males and females. Traits that affect fitness components, as well as mating success, are under polygenic determination, with very complex gene interactions. Although secondary sexual traits were usually analyzed as target of sexual selection, many other traits can determine male attractiveness. Traits such as morphological, physiological, behavior and other, affecting mating success, can be termed as condition-dependent traits. In order to test this hypothesis, that sexual selection can reduce mutational load, two experimental groups were formed from the same population genetic pool of Drosophila subobscura, which differed in the level of mutational load. Mutations were induced in one group, using 30Gy ionizing radiation. The effect of sexual selection in reduction of mutational load was measured through different components of male mating behavior (courtship occurrence, courtship latency, courtship intensity, mating occurrence,latency to mating and duration of mating)...

    Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)

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    Even has been under study since 1935, zinc oxide (ZnO) based materials still attract a huge scientific attention. Owing to a wide band gap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) ZnO has a variety of application, e.g. in electronics, optoelectronics, spintronics and photocatalysis. Besides, it has been shown that zinc oxide-based materials have a great potential as photoelectrocatalysts in the processes of water splitting, yielding an increased both photocurrent density and photoconversion efficiency. However, with a band gap energy of 3.37 eV, ZnO is restricted to absorb UV light only. This restriction can be overcome by modifying optical properties of zinc oxide particles. During the years different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials, for example: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc. In this study we employed 3d metal ion substitution to improve visible light-driven photoactivity of zinc oxide particles. We investigated the influence of Fe concentration in Zn1-xFeyO(1-x+1.5y) nanoparticles on crystal structure, textural, optical and photoelectrocatalytic properties. Zn1-xFeyO(1-x+1.5y) nanoparticles with nominally 5, 10, 15 and 20 at.% of Fe ions were synthesized by microwave processing of a precipitate. The crystal structure and phase purity of the samples were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. Mössbauer spectroscopy was carried out to clarify the valence state of the iron ions in the ZnO crystal structure. Effects of the iron ions concentration on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) with elemental mapping, and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Photoelectrochemical activity of the Zn1-xFeyO(1-x+1.5y) samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared. In addition, a series of first principles calculations were performed to address the influence of the iron concentration on the electronic structure of Zn1-xFeyO(1-x+1.5y) samples

    CaCu3Ti4-xRuxO12: Crystal structure, electrical and magnetic properties

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    The CaCu3 Ti 4 O12 belongs to the large ACu3B4 O12 family of materials. Crystallographic A site is most often occupied by alkaline-earth metals or lanthanides, while B site is occupied by transition metals. The type of cations that build up the structure strongly affects the properties of these. The CaCu 3 Ti 4 O12 has been extensively studied due to its high dielectric permittivity stable over a wide temperature and frequency range (up to 10 5 , for 100-600 K and 10 2 –105 Hz). Because of such characteristics, it has promising application in microelectronics. However, it has been shown that differences in the crystal structure and electrical properties of dielectric ceramics and metallic electrodes, may cause an energy barrier and occurrence of stress on the ceramic-electrode contact which reduces dielectric permittivity. Such stress can be prevented by using dielectric and electrode materials with as much as possible similar crystal structure, especially unit cell parameters. This investigation dealt with detailed structural (XRPD, HRTEM, SAED), dielectric and magnetic study of CaCu 3 Ti 4-xRuxO12 (CCTRO, x = 0, 1 and 4) materials. The results of structural refinement show that in cubic symmetry with space group 3Im , both titanium and ruthenium ions occupied crystallographic B site. Moreover, the variation in stoichiometry slightly affects the value of the unit cell parameters but changes electrical properties of studied material. Thus, substitution of even one atom of Ru in CaCu3 Ti 4-xRuxO12 unit cell is enough to change material properties from dielectric to conductor solving the problem of stress appearance on the contact layer of dielectric/electrode in capacitors.IX Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 20-21, 2021; Belgrad

    Excitatory-inhibitory balance within EEG microstates and resting-state fMRI networks: assessed via simultaneous trimodal PET-MR-EEG imaging

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    The symbiosis of neuronal activities and glucose energy metabolism is reflected in the generation of functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) signals. However, their association with the balance between neuronal excitation and inhibition (E/I-B), which is closely related to the activities of glutamate and γ-aminobutyric acid (GABA) and the receptor availability (RA) of GABAA and mGluR5, remains unexplored. This research investigates these associations during the resting state (RS) condition using simultaneously recorded PET/MR/EEG (trimodal) data. The trimodal data were acquired from three studies using different radio-tracers such as, [11C]ABP688 (ABP) (N = 9), [11C]Flumazenil (FMZ) (N = 10) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG) (N = 10) targeted to study the mGluR5, GABAA receptors and glucose metabolism respectively. Glucose metabolism and neuroreceptor binding availability (non-displaceable binding potential (BPND)) of GABAA and mGluR5 were found to be significantly higher and closely linked within core resting-state networks (RSNs). The neuronal generators of EEG microstates and the fMRI measures were most tightly associated with the BPND of GABAA relative to mGluR5 BPND and the glucose metabolism, emphasising a predominance of inhibitory processes within in the core RSNs at rest. Changes in the neuroreceptors leading to an altered coupling with glucose metabolism may render the RSNs vulnerable to psychiatric conditions. The paradigm employed here will likely help identify the precise neurobiological mechanisms behind these alterations in fMRI functional connectivity and EEG oscillations, potentially benefitting individualised healthcare treatment measures

    mGluR5 receptor availability is associated with lower levels of negative symptoms and better cognition in male patients with chronic schizophrenia

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    Consistent findings postulate disturbed glutamatergic function (more specifically a hypofunction of the ionotropic NMDA receptors) as an important pathophysiologic mechanism in schizophrenia. However, the role of the metabotropic glutamatergic receptors type 5 (mGluR5) in this disease remains unclear. In this study, we investigated their significance (using [11 C]ABP688) for psychopathology and cognition in male patients with chronic schizophrenia and healthy controls. In the patient group, lower mGluR5 binding potential (BPND ) values in the left temporal cortex and caudate were associated with higher general symptom levels (negative and depressive symptoms), lower levels of global functioning and worse cognitive performance. At the same time, in both groups, mGluR5 BPND were significantly lower in smokers (F[27,1] = 15.500; p = .001), but without significant differences between the groups. Our findings provide support for the concept that the impaired function of mGluR5 underlies the symptoms of schizophrenia. They further supply a new perspective on the complex relationship between tobacco addiction and schizophrenia by identifying glutamatergic neurotransmission-in particularly mGluR5-as a possible connection to a shared vulnerability. Keywords: chronic schizophrenia; cognition; mGluR5 receptor; negative symptoms; positron emission tomography

    D7.3 - Data Management Plan

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    This document describes the initial version of the Data Management Plan (DMP) for the WaPoDe project. The overall objective of the WaPoDe project is to synthetize materials with enhanced sensitivity, selectivity, and response time as electrochemical sensors (ECS) for detection and monitoring of different pharmaceutical and pesticide pollutants in water and to reduce ECS manufacturing costs. The focus of the WaPoDe project is on ZnO-based electrochemical sensors. The database will be developed under the WaPoDe project with the main purpose to summarize the WaPoDe research results on the types, properties, and application of ZnO-based nanoparticles as selective ECS. This initial DMP provides information on the data management principles that will be implemented during and for a certain period after the WaPoDe project completion. It is based on the Data Management Plan template (https://enspire.science/wp-content/uploads/2021/09/Horizon-Europe-Data-Management-Plan-Template.pdf) which follows the guidelines from Europe Horizon calls. This DMP will be regularly updated as the implementation of the project progresses. The draft DMP was developed within the project workpackages

    Potentiometric and Spectrophotometric Determination of Dissociation Constants of Cefetamet

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    Summary. The dissociation constants of cefetamet-Na have been determined using potentiometric titrations and spectrophotometry. The investigations were carried on in water solutions at constant temperature and ionic strength, and at different H0 and pH values. Potentiometric investigations were performed at three different temperatures and ionic strengths. The concentration dissociation constants and the corresponding thermodynamic dissociation constants were calculated by a computer program. The mixed dissociation constants (pK') of cefetamet-Na have been determined spectrophotometrically in the H0 range from -5.80 to 0.00 and at pH values from 0.00 to 12.70 and are in good agreement with values achieved by graphical methods as well as with those obtained by potentiometric methods. Based on the determined values, the thermodynamic parameters (AG, AH, AS) were calculated at I = 0.1 M
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