THE EFFECT OF LABORATORY COLONY CONDITION ON THE TROPHALLACTIC INTERACTIONS OF CAMPONOTUS VAGUS (HYMENOPTERA: FORMICIDAE)

In this study, our aim was to give a detailed evaluation of the trophallactic interactions among foragers of Camponotus vagus in outside-nest situation, and to find out which properties of trophallaxis may have a role in the information-flow among workers about current nutritional state of the colony. Measured parameters were the number and frequency of trophallactic interactions, the duration of trophallaxes, the frequency of different duration interactions, and the number and size-class of workers participating in trophallactic events outside the nest. Experiments were conducted both with starved and satiated colonies to examine the effect of feeding condition. We demonstrated that the dynamics of trophallaxis is a stable parameter; it was independent from the starvation level. Similarly,the number of partners and the size class distribution of the different sized worker pairs did not differ between the two colony states. Starvation level influenced both the frequency and mean duration of trophallactic interactions. The frequency-distribution of the duration of trophallactic events showed an exponential trend, i.e., the short term interactions were more frequent than the prolonged ones in both colony states. However, the rate of these two distinguished types of trophallaxis was different in the case of the two colony conditions. Different rates of the short term and prolonged interactions may provide information about the current nutritional requirements of the colony, enhancing the speed and efficiency of colony responses to feeding stress. Frequent short term trophallaxis may not only contribute to a high level of cooperation during retrieval of food among foragers, but also maintain the integration of colony members even outside their nest

CLOSE NESTING ASSOCIATION OF TWO ANT SPECIES IN ARTIFICIAL SHELTERS: RESULTS FROM A LONG-TERM EXPERIMENT

Close nesting (real or quasi plesiobiosis) is the simplest form of spatial associations of heterospecific ant colonies that share the same microhabitat, but remain separate as individual units. We studied the tendency to close nesting between two ant species, Lasius psammophilus and Plagiolepis taurica, under slate plates used as artificial nesting sites during a 34 years long study period. 2410 nest records of 11 ant species were made under the plates, and a total of 181 close nesting associations were observed, most of which between L. psammophilus and P. taurica. The hypothesis of the weak antagonism between the two species was supported by (1) the rate of nesting associations, which was lower than expected from random probabilities; (2) the maximum of the index of avoidance, at intermediate densities; (3) the negative relationship between the unoccupied nesting shelters and the frequency of close nesting; (4) the tendency of individual and group level avoidance and (5) the low rate of interspecific aggression. The benefit of choosing favorable nesting sites and the risk of interspecific competition are in trade-off relation and the attractiveness of nesting shelters is the stronger constraint; therefore it can be regarded as the primary driver of the formation of spatial associations between the colonies of the two studied species

Nesting Associations without Interdependence: A Preliminary Review on Plesiobiosis in Ants

Plesiobiosis, the most basic form of interspecific associations in ants, denotes occasional or regular nesting of heterospecific colonies of certain species pairs in close proximity to each other without biological interdependence. Plesiobionts differ from each other both in morphology and in behaviour (e.g., in their foraging strategies), and at least one of the plesiobiotic pair is a submissive species. Recent studies on plesiobiosis have revealed that Formica fusca and Lasius flavus are two of the most frequent plesiobionts. To date, at least 48 different plesiobiotic species pairs have been recorded from various habitat types of the Holarctic region. Two main habitat properties may play a role in the forming of plesiobiosis: the scarcity of suitable nesting sites as a forcing factor and the sufficient amount of food sources available, influencing the abundance of colonies. Thus, high colony density may contribute to the formation of such associations, resulting in (1) frequent nesting in each other's neighbourhood and (2) stronger intraspecific competition, which forces colonies into the vicinity of heterospecific nests. Plesiobiotic associations formed this way may promote persistent coexistence, leading to the formation of other types of interspecific associations (e.g., clepto-or lestobiosis)

Enantioselective Synthesis of 8-Hydroxyquinoline Derivative, Q134 as a Hypoxic Adaptation Inducing Agent

Hypoxia is a common feature of neurodegenerative diseases, including Alzheimer’s disease that may be responsible for disease pathogenesis and progression. Therefore, the hypoxia-inducible factor (HIF)1 system, responsible for hypoxic adaptation, is a potential therapeutic target to combat these diseases by activators of cytoprotective protein induction. We have selected a candidate molecule from our cytoprotective hydroxyquinoline library and developed a novel enantioselective synthesis for the production of its enantiomers. The use of quinidine or quinine as a catalyst enabled the preparation of enantiomer-pure products. We have utilized in vitro assays to evaluate cytoprotective activity, a fluorescence-activated cell sorting (FACS) based assay measuring mitochondrial membrane potential changes, and gene and protein expression analysis. Our data showed that the enantiomers of Q134 showed potent and similar activity in all tested assays. We have concluded that the enantiomers exert their cytoprotective activity via the HIF1 system through HIF1A protein stabilization

Synthesis and Cytoprotective Characterization of 8- Hydroxyquinoline Betti Products

The 8-hydroxyquinoline pharmacophore scaffold has been shown to possess a range of activities as metal chelation, enzyme inhibition, cytotoxicity, and cytoprotection. Based on our previous findings we set out to optimize the scaffold for cytoprotective activity for its potential application in central nervous system related diseases. A 48-membered Betti-library was constructed by the utilization of formic acid mediated industrial-compatible coupling with sets of aromatic primary amines such as anilines, oxazoles, pyridines, and pyrimidines, with (hetero)aromatic aldehydes and 8-hydroxiquinoline derivatives. After column chromatography and re-crystallization, the corresponding analogues were obtained in yields of 13–90%. The synthesized analogs were optimized with the utilization of a cytoprotection assay with chemically induced oxidative stress, and the most active compounds were further tested in orthogonal assays, a real time cell viability method, a fluorescence-activated cell sorting (FACS)-based assay measuring mitochondrial membrane potential changes, and gene expression analysis. The best candidates showed potent, nanomolar activity in all test systems and support the need for future studies in animal models of central nervous system (CNS) disorders

Hypoalbuminemia affects one third of acute pancreatitis patients and is independently associated with severity and mortality

The incidence and medical costs of acute pancreatitis (AP) are on the rise, and severe cases still have a 30% mortality rate. We aimed to evaluate hypoalbuminemia as a risk factor and the prognostic value of human serum albumin in AP. Data from 2461 patients were extracted from the international, prospective, multicentre AP registry operated by the Hungarian Pancreatic Study Group. Data from patients with albumin measurement in the first 48 h (n = 1149) and anytime during hospitalization (n = 1272) were analysed. Multivariate binary logistic regression and Receiver Operator Characteristic curve analysis were used. The prevalence of hypoalbuminemia (< 35 g/L) was 19% on admission and 35.7% during hospitalization. Hypoalbuminemia dose-dependently increased the risk of severity, mortality, local complications and organ failure and is associated with longer hospital stay. The predictive value of hypoalbuminemia on admission was poor for severity and mortality. Severe hypoalbuminemia (< 25 g/L) represented an independent risk factor for severity (OR 48.761; CI 25.276-98.908) and mortality (OR 16.83; CI 8.32-35.13). Albumin loss during AP was strongly associated with severity (p < 0.001) and mortality (p = 0.002). Hypoalbuminemia represents an independent risk factor for severity and mortality in AP, and it shows a dose-dependent relationship with local complications, organ failure and length of stay.Peer reviewe

A Formica fusca és Camponotus vagus hangyafajok koegzisztenciájának formái és feltételei erdőssztyepp élőhelyeken

Az interspecifikus asszociációk legkezdetlegesebb formája a pleziobiózis, hisz ez interakciók nélküli gyakori térbeli fészekszomszédságot, közös tanyahely-használatot jelent bizonyos fajpárok kolóniái között. Adott fajpárok alakíthatnak ki egymással pleziobiotikus asszociációt, ezek az úgynevezett pleziobionta fajok. Minél inkább különbözik egymástól két faj, annál nagyobb valószínűséggel alakulhat ki közöttük ilyen jellegű kapcsolat: a pleziobionták testmérete, morfológiája és viselkedése eltérő, a viselkedés kapcsán elsősorban az eltérő táplálkozási stratégia emelhető ki. Tekintve, hogy az ily módon egymás szomszédságában élő kolóniák ugyanazt a mikrohabitatot használják (tanyahely és táplálkozási terület), a kapcsolattartós fennmaradását nagymértékben befolyásolhatja és elősegítheti a fajok morfológiai és viselkedésbeli különbözősége, hiszen az átfedő jellegek erősebb kompetitív helyzetet eredményezhetnek.A pleziobiotikus kapcsolatok kialakulásában bizonyos háttértényezők jelentős szerepet játszhatnak.A megfelelő táplálékellátottság szerepe igen jelentős, hisz elősegítheti a potenciális pleziobionták kolóniáinak nagy denzitását. A nagy denzitás erősítheti az intraspecifikus kolóniák közötti negatív kölcsönhatások (pl: kompetíció, teritoriális viselkedés és az ezzel kapcsolatos agresszivitás stb.) erősségét, mely az alkalmas fészkelőhelyek hiányával társulva hozzájárulhat a pleziobiotikus asszociációk létrejöttéhez. 2013-ig 48 különböző pleziobiotikus fajpár volt ismert a Holarktikus régió eltérő típusú élőhelyeiről. A négy leggyakoribb génusz melyek tagjai pleziobiotikus kapcsolatot alakítottak ki, a Formica, Camponotus, Lasiusés Myrmicagénusz. Az ismert pleziobiotikus partnerfajaik száma alapján az egyik leggyakoribb pleziobionta faj a Formica fusca Linnaeus, 1758. Értekezésem két pleziobionta faj, a Formica fusca és Camponotus vagus hangyafajok koegzisztenciájának formáival és annak feltételeivel foglalkozik, melyet erdőssztyepp élőhelyeken, valamint laboratóriumi körülmények között vizsgáltam. Disszertációm tárgyát képező vizsgálataim során négy fő célkitűzést kívántam megvalósítani: megállapítani 1) a F. fusca és C. vagus fészkeinek térbeli mintázatát és a térbeli mintázat háttértényezőit különböző erdőtípusokban, 2) a vizsgált fajok populációinak közösségi szintű beágyazottságát, 3) az F. fusca és C. vaguspopulációk koegzisztenciájának háttérmechanizmusait, 4) valamint részletesen vizsgáltam a táplálkozási térhasználat populáción belüli mechanizmusai közül a C. vagus dolgozók közötti trofallaxisokat

Nesting Associations without Interdependence: A Preliminary Review on Plesiobiosis in Ants

Plesiobiosis, the most basic form of interspecific associations in ants, denotes occasional or regular nesting of heterospecific colonies of certain species pairs in close proximity to each other without biological interdependence. Plesiobionts differ from each other both in morphology and in behaviour (e.g., in their foraging strategies), and at least one of the plesiobiotic pair is a submissive species. Recent studies on plesiobiosis have revealed that Formica fusca and Lasius flavus are two of the most frequent plesiobionts. To date, at least 48 different plesiobiotic species pairs have been recorded from various habitat types of the Holarctic region. Two main habitat properties may play a role in the forming of plesiobiosis: the scarcity of suitable nesting sites as a forcing factor and the sufficient amount of food sources available, influencing the abundance of colonies. Thus, high colony density may contribute to the formation of such associations, resulting in (1) frequent nesting in each other's neighbourhood and (2) stronger intraspecific competition, which forces colonies into the vicinity of heterospecific nests. Plesiobiotic associations formed this way may promote persistent coexistence, leading to the formation of other types of interspecific associations (e.g., clepto- or lestobiosis)