Self-organizing patterns maintained by competing associations in a six-species predator-prey model

Formation and competition of associations are studied in a six-species ecological model where each species has two predators and two prey. Each site of a square lattice is occupied by an individual belonging to one of the six species. The evolution of the spatial distribution of species is governed by iterated invasions between the neighboring predator-prey pairs with species specific rates and by site exchange between the neutral pairs with a probability $X$. This dynamical rule yields the formation of five associations composed of two or three species with proper spatiotemporal patterns. For large $X$ a cyclic dominance can occur between the three two-species associations whereas one of the two three-species associations prevails in the whole system for low values of $X$ in the final state. Within an intermediate range of $X$ all the five associations coexist due to the fact that cyclic invasions between the two-species associations reduce their resistance temporarily against the invasion of three-species associations.Comment: 6 pages, 8 figure

The measurement of dissolved oxygen today - tradition and topicality

Today, the determination of the dissolved oxygen content of natural waters is practically an essential duty whenever background data is collected for investigations of a hydrobiological, ecological, and nature or environmental protection viewpoint. If the method by which the measurements are carried out is concerned, it can be stated that the 120 year old, classical Winkler-method is inevitable even today. However the development of hydroecological sciences have laid claim to such expectations that the necessity of in situ oxygen determinations have become increasingly important. In our work we present the survival of the traditional Winkler-method in the present practice, we review all those viewpoints which have facilitated the widespread application of in situ oxygen determinations as well as the methods of all the measurements that are presently regularly applied in the investigations of natural waters

Laboratory von H\'amos X-ray Spectroscopy for Routine Sample Characterization

High energy resolution, hard X-ray spectroscopies are powerful element selective probes of the electronic and local structure of matter, with diverse applications in chemistry, physics, biology and materials science. The routine application of these techniques is hindered by the complicated and slow access to synchrotron radiation facilities. Here we propose a new, economic, easily operated laboratory high resolution von H\'amos type X-ray spectrometer, which offers rapid transmission experiments for X-ray absorption, and is also capable of recording X-ray emission spectra. The use of a cylindrical analyzer crystal and a position sensitive detector enabled us to build a maintenance free, flexible setup with low operational costs, while delivering synchrotron grade signal to noise measurements in reasonable acquisition times. We demonstrate the proof of principle and give examples for both measurement types. Finally, tracking of a several day long chemical transformation, a case better suited for laboratory than synchrotron investigation, is also presented

Cardiac Magnetic Resonance Imaging of the Myocardium in Chronic Kidney Disease

Early stages of chronic kidney disease (CKD) are often underdiagnosed, while their deleterious effects on the cardiovascular (CV) system are already at work. Thus, the assessment of early CV damage is of crucial importance in preventing major CV events. Myocardial fibrosis is one of the major consequences of progressive CKD, as it may lead to reentry arrhythmias and long-term myocardial dysfunction predisposing to sudden death and/or congestive heart failure. Subclinical myocardial fibrosis, with a potential key role in the development of uraemic cardiac disease, can be measured and characterised by appropriate cardiac magnetic resonance (CMR) techniques. Fibrosis detection was initially based on the contrast agent gadolinium, due to the superiority in sensitivity and accuracy of contrast-based methods in fibrosis assessment relative to native techniques. However, the severe consequences of gadolinium administration in uraemia (nephrogenic systemic fibrosis) have forced practitioners to re-evaluate the methodology. In the present overview, we review the possible contrast-based and contrast agent-free CMR techniques, including native T1 relaxation time, extracellular volume and global longitudinal strain measurement. The review also summarises their potential clinical relevance in CKD patients based on recently published studies

Effect of pulsed electromagnetic fields on endoplasmic reticulum stress

The maintenance of protein homeostasis in the endoplasmic reticulum (ER) is crucial in cell life. Disruption of proteostasis results in ER stress that activates the unfolded protein response (UPR); a signalling network assigned to manage the accumulated misfolded or unfolded proteins. Prolonged or unresolved ER stress leads to apoptotic cell death that can be the basis of many serious diseases. Our aim was to study the effect of pulsed electromagnetic fields (PEMF), an alternative, non-invasive therapeutic method on ER stressed cell lines. First, the effect of PEMF treatment on the expression of ER stress markers was tested in three different cell lines. PEMF had no remarkable effect on ER stress protein levels in human embryonic kidney (HEK293T) and human liver carcinoma (HepG2) cell lines. However, the expression of BiP, Grp94 and CHOP were increased in HeLa cells upon PEMF exposure. Therefore, HepG2 cell line was selected for further experiments. Cells were stressed by tunicamycin and exposed to PEMF. Grp94, PDI, CHOP and PARP expression as markers of stress were monitored by Western blot and cell viability was also investigated. Tunicamycin treatment, as expected, increased the expression of Grp94, PDI, CHOP and inactivated PARP. Analysis of protein expression showed that PEMF was able to decrease the elevated level of ER chaperons Grp94, PDI and the apoptosis marker CHOP. The truncated, inactive form of PARP was also decreased. Accordingly, cell viability was also improved by PEMF exposure. These results indicate that PEMF is able to moderate ER stress induced by tunicamycin in HepG2 cells. However, our results clearly draw attention to that different cell lines may vary in the response to PEMF treatment. © 2016, Polish Physiological Society. All rights reserved

Plant regeneration from seedling explants of common bean : Phaseolus vulgaris L.

For shoot induction and plant regeneration in bean we used MS media+BA and NAA. Multiple shoot induction was obtained in case of P. vulgaris cv. Fônix and Maxidor. The efficiency of regeneration from intact seedling (IS) and cotyledonary node (CN) explants was compared. The optimum treatment for the induction of multiple shoot formation was the culturing of (IS) on MS-based media+BA and NAA. Multiple shoot induction on dry bean (CN) cultured on full MS medium+1mg/l BA and 0.1mg/l NAA was feasible. Shoots that were 2cm in length or longer and having 2 trifoliate leaves were responsible for rooting ability, and root development. The method can be applied in transformation experiments

A farmakológiai funkcionális mágneses rezonancia vizsgálat (phMRI) felhasználásának lehetőségei a hangulatzavarok kutatásában | Application of pharmaco functional magnetic resonance imaging (phMRI) in the research of affective disorders

Napjaink leggyakoribb pszichiátriai betegségei, a depresszió és a szorongásos zavarok, feltehetőleg a központi idegrendszer monoamin neurotranszmissziójának elégtelenségével kapcsolatosak. Ugyanakkor ezeknek a patofiziológiai folyamatoknak a vizsgálata az élő emberi agyban komoly kihívást jelent. A funkcionális mágneses rezonancia képalkotás (fMRI) olyan noninvazív módszer, ami lehetőséget nyújt az agyi aktivitás vizsgálatára. Legtöbb esetben az aktivitást előidéző stimulus kognitív pszichológiai feladat, azonban lehetőség nyílik arra, hogy farmakológiai funkcionális mágneses rezonancia (phMRI) vizsgálat során egy specifikus farmakon indukálta aktivitásváltozást vizsgáljunk. Jelen munkánk célja az ezzel a módszerrel végzett eredmények összefoglalása, melyet a PubMed adatai alapján készítettünk el. A challenge phMRI vizsgálatok során egy szelektív farmakon, például a szelektív szerotonin visszavétel gátló (SSRI) citalopram és escitalopram alkalmazásával a szerotonerg neurotranszmisszió és a gyógyszerhatásban résztvevő agyi területek aktivitásváltozása vizsgálható. Modulation phMRI segítségével megfigyelhetjük, milyen akut hatással van az adott farmakon alkalmazása az olyan kognitív pszichés funkciókra, mint az érzelemfeldolgozás, és hogyan változnak meg ezek a funkciók hosszabb távú gyógyszeralkalmazást követően. A phMRI különböző módszerei ezért komoly segítséget nyújthatnak abban, hogy az emberi agy szerotonerg transzmissziójának szerepét és az ezzel összefüggő pszichés betegségek patomechanizmusát jobban megérthessük | Many common psychiatric disorders such as depression and anxiety disorders are associated with dysfunction in the monoamine neurotransmission in the central nervous system. However, the investigation of these pathophysiological processes in the human living brain is difficult. In case of functional magnetic resonance imaging (fMRI), a non-invasive method for the examination of brain activity, the activity-inducing stimulus is generally a cognitive psychological test, while during pharmacological magnetic resonance imaging (phMRI) the activation is triggered by a specific pharmacon. In the present work we review the available scientific literature related to this method using literature search in PubMed. Through application of a selective pharmacon like the selective serotonine reuptake inhibitors (SSRIs) citalopram or escitalopram in a challenge phMRI study, the serotonergic neurotransmitter system can be examined specifically, the functioning brain areas involved in its effect become observable.. With modulation phMRI we can monitor the long-term effect of an antidepressant or we can examine the immediate effect of a single dose of the medication on congitive psychological functions like emotional processing. Thus, the application of phMRI methods may help deepen our understanding of serotonergic function in the living human brain as well as of diseases related to serotonergic neurotransmitter system dysfunction