Search results for "Sms"
showing 10 items of 10610 documents
Collateral sensitivity of natural products in drug-resistant cancer cells
2018
Cancer chemotherapy is frequently hampered by drug resistance. Concepts to combine anticancer drugs with different modes of action to avoid the development of resistance did not provide the expected success in the past, because tumors can be simultaneously non-responsive to many drugs (e.g. the multidrug resistance phenotype). However, tumors may be specifically hypersensitive to other drugs - a phenomenon also termed collateral sensitivity. This seems to be a general biological mechanism, since it also occurs in drug-resistant Escherichia coli and Saccharomyces cerevisiae. Here, we give a timely and comprehensive overview on hypersensitivity in resistant cancer cells towards natural produc…
Predators' consumption of unpalatable prey does not vary as a function of bitter taste perception
2020
Many prey species contain defensive chemicals that are described as tasting bitter. Bitter taste perception is, therefore, assumed to be important when predators are learning about prey defenses. However, it is not known how individuals differ in their response to bitter taste, and how this influences their foraging decisions. We conducted taste perception assays in which wild-caught great tits (Parus major) were given water with increasing concentrations of bitter-tasting chloroquine diphosphate until they showed an aversive response to bitter taste. This response threshold was found to vary considerably among individuals, ranging from chloroquine concentrations of 0.01 mmol/L to 8 mmol/L.…
Aquatic and Semiaquatic Heteroptera (Nepomorpha) from the Strei River Basin
2018
Abstract During a field campaign in the Strei River basin in August 2014, seven suitable habitats for aquatic and semi-aquatic true bugs were identified from the confluence of the Strei River with the Bărbat River down to the confluence with the Mureș River. Forty-eight individuals belonging to 15 species and nine families of aquatic and semi-aquatic true bugs were sampled. We mention two species considered rare in Romanian fauna: Hebrus montanus and Microvelia pygmaea. The statistic-mathematical analysis showed the similarity of the true bugs’ communities from habitats with similar conditions, as well as the relation of each species with particular habitat conditions, emphasizing the fact …
Mediterranean identities - environment, society, culture
2017
The Mediterranean Sea, one of the most complex marine ecosystems, is inhabited by a rich and diverse biota which is disproportionate to its dimensions. It is cur‐ rently affected by different pressures, mainly driven by human activities such as cli‐ mate change and bioinvasions. This Sea, also due to its geographic position (wedged between the temperate climate of central Europe and the arid climate of northern Africa), seems to be one of the regions most susceptible to global climate change. The increased rates of introduction and spread of marine alien species may represent a supplementary stress factor to Mediterranean marine native biota already challenged by climatic abnormalities. The…
Proposing a Technical Solution for Restoring Longitudinal Connectivity in the Brădeni/Retiş Accumulation Area on Hârtibaciu River
2016
Abstract The fish fauna of the Hârtibaciu River has experienced a disrupted connectivity due to the hydrotechnical works and the Brădeni/Retiş Dam located across the Hârtibaciu watercourse being one of this significant obstacles. The newly proposed constructed wetlands can improve the habitat quality for the fish species of conservative interest sampled in the Brădeni/Retiş Dam proximity Rhodeus amarus, and can increase the individuals’ number of this population. Also can benefit the local populations of Phoxinus phoxinus and Gobio obtusirostris. Using gravitational force and also the underground layout, a proposed technical solution gives maximum safety regarding the water supply for the n…
Decoding Group Vocalizations: The Acoustic Energy Distribution of Chorus Howls Is Useful to Determine Wolf Reproduction
2016
Population monitoring is crucial for wildlife management and conservation. In the last few decades, wildlife researchers have increasingly applied bioacoustics tools to obtain information on several essential ecological parameters, such as distribution and abundance. One such application involves wolves (Canis lupus). These canids respond to simulated howls by emitting group vocalizations known as chorus howls. These responses to simulated howls reveal the presence of wolf litters during the breeding period and are therefore often used to determine the status of wolf populations. However, the acoustic structure of chorus howls is complex and discriminating the presence of pups in a chorus i…
Determining Cellulolytic Activity of Microorganisms
2020
Abstract Decomposition of cellulose to glucose requires complex cooperation of glycoside hydrolase enzymes. As a result of glycoside β-1,4 bonds hydrolysis, shorter chains of cellulose, oligodextrin, cellobiose and glucose are created. A number of bacteria and fungi demonstrate the capacity to degrade cellulose. Their activity can be assessed with the use of qualitative and quantitative methods. Qualitative methods with the use of e.g. Congo red, are used in screening studies, however, they do not provide information about the quantity of the produced enzyme. Spectrophotometric methods are more accurate and they measure the quantities of reducing sugars with the use of appropriate substrate…
Hyperparasitoids exploit herbivore-induced plant volatiles during host location to assess host quality and non-host identity
2019
Although consumers often rely on chemical information to optimize their foraging strategies, it is poorly understood how top carnivores above the third trophic level find resources in heterogeneous environments. Hyperparasitoids are a common group of organisms in the fourth trophic level that lay their eggs in or on the body of other parasitoid hosts. Such top carnivores use herbivore-induced plant volatiles (HIPVs) to find caterpillars containing parasitoid host larvae. Hyperparasitoids forage in complex environments where hosts of different quality may be present alongside non-host parasitoid species, each of which can develop in multiple herbivore species. Because both the identity of th…
Sexual antagonism for testosterone maintains multiple mating behaviour
2011
Summary 1. The persistence of multiple mating remains one of the fundamental questions in evolutionary biology. In theory, multiple mating is predicted to improve female fitness cumulatively through direct and ⁄ or genetic benefits. However, intra-locus sexual conflicts may potentially constrain or even eliminate these benefits owing to the gender load imposed by sexually antagonistic selection. 2. Here, we tested whether sexually antagonistic selection can maintain the variance in multiple mating behaviour of bank voles (Myodes glareolus) by manipulating the hormone testosterone through artificial selection in the laboratory. Among mammals, testosterone is a sexually dimorphic fitness-rela…
Sexual selection on song and cuticular hydrocarbons in two distinct populations ofDrosophila montana
2011
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild-collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify t…