We tested the hypothesis that males of meadow pipits (Anthus pratensis) respond differentially to simulated territorial intrusions (song playback + bird model) by conspecific, related (tree pipit, Anthus trivialis), and unrelated individuals (willow warbler, Phylloscopus trochilus), and evaluated the effect of playback order. All tested males responded aggressively to the conspecific playback; reactions to heterospecific stimuli occurred only after previous excitation by the conspecific song and dummy, and were usually weaker. Apparently, although males were able to discriminate between playbacks, excitation by intrusion of a conspecific rival elicited an aggressive reaction to otherwise neutral stimuli. Reactions to heterospecific playbacks closely following the conspecific one did not differ significantly between congeneric and unrelated species. The response to a subsequent heterospecific stimulus, however, was taxon-dependent: congeneric species elicited a significantly stronger reaction than an unrelated one. We presume that this was due to the morphological similarity between pipits, and that the more intensive reaction could have been caused by stronger visual stimulus from the respective model. We discuss the potential benefits as well as limitations of using models (dummies) in playback experiments, and suggest that overexcitation by previous stimuli should be considered during experimental setup and data analysis in studies focusing both on interspecific aggressiveness and on neighbour-stranger interactions.
Despite recent advancements in reproductive medicine, recurrent implantation failure and habitual abortion remain ongoing issues. One of the most important aspects of successful implantation is the intricate immune response and regulation necessary for the acceptance of the hemiallogenic embryo. The most numerous immune cells in the decidua are uterine natural killer cells (uNK). Studies suggest that changes in the uNK count and physiology may be responsible for the aforementioned pathological conditions. Thus, testing for uNK may provide valuable insights into their pathogenesis. The study compared Pipelle endometrial sampling with conventional curettage to find out whether the less invasive Pipelle method is a viable alternative of tissue collection. Tissue samples from 14 patients obtained by both methods were examined. The average size of tissue samples obtained with Pipelle was 17 mm2 , samples obtained with curettage had on average 34 mm2 . Using immunohistochemical visualization of CD56 (NK cells) and granzyme B antigens (serine protease-expressing activation state of NK cells), it was found that the average total count of CD56 / mm2 was 115 for Pipelle and 120 for curettage, respectively. The study also proved a correlation between granzyme B positivity and identification of NK cells clusters. The results indicated that Pipelle endometrial sampling seems a suitable method of tissue harvesting for the purpose of uNK cells examination. Pipelle endometrial sampling is safe, cost-effective and can be performed on an outpatient basis without the need of anesthesia or analgesia. Several issues remain yet to be solved: how to standardize the subsequent uNK testing, how to interpret the results and finally yet importantly, how to use this knowledge in personalized treatment protocols.
White adipose tissue (WAT) represents a reservoir of lipophilic environmental pollutants, especially of those which are resistant to biological and chemical degradation – so-called persistent organic pollutants (POPs). Large amounts of different congeners and isomers of these compounds exhibit a variety of adverse biological effects. Interactions among different classes of compounds, frequently with opposing effects, complicate hazard evaluation and risk assessment. WAT is the key organ for energy homeostasis and it also releases metabolites into the circulation and adipokines with systemic effects on insulin sensitivity and fuel partitioning in muscles and other tissues. Its beneficial role is lost in obesity when excessive accumulation of WAT contributes to severe diseases, such as diabetes. POPs may crossroad or modulate the effect of endogenous ligands of nuclear transcription factors, participating in differentiation, metabolism and the secretory function of adipocytes. These mechanisms include, most importantly: i) endocrine disrupting potency
of POPs ́ mixtures on androgen, estrogen or thyroid hormone metabolism/functions in WAT, ii) interference of dioxin-like chemicals with retinoic acid homeostasis, where impact on retinoid receptors is expected, and iii) interaction with transcriptional activity of peroxisome proliferator-activated receptors is likely. Thus, the accumulation and action of
POPs in WAT represents a unitary mechanism explaining, at least in part, the effects of POPs in the whole organism. By modulating WAT differentiation, metabolism and function, the POPs could affect not only the physiological role of WAT, but they may also influence the development of obesity-associated diseases.
Semi-dry grasslands in the White Carpathian (Bílé Karpaty) Mountains on the Czech-Slovak border are famous for their extremely high species richness. In places they contain more than 130 species of vascular plants per 100m2 and for some plot sizes they hold world records in the number of vascular plant species, but the reasons for this are poorly understood. Here we ask whether the high number of species in these grasslands can be explained by local ecological factors. We compared the White Carpathian grasslands with similar grasslands in adjacent areas in the west (southern Moravia) and the east (Inner Western Carpathians), which are on average notably poorer in species than those in the White Carpathians. In both of these areas, we sampled grasslands that were among the species richest in the regional context and had a similar physiognomy, species composition and ecology as those in the White Carpathians. We found 75 sites with >70 and >25 species of vascular plants per 100 m2 and 1 m2, respectively, in which we recorded species composition and local environmental conditions, including precipitation, soil depth, soil pH and nutrient concentrations, above-ground biomass production and nutrients in plant biomass. Although the White Carpathian grasslands were considerably richer in species than the richest grasslands in the adjacent regions, there were no differences in the values of the factors studied that could provide an unequivocal explanation of their high species richness. However, the values of the factors studied were within the ranges reported in the literature as conducive to high species richness in temperate grasslands. We conclude that the high species richness recorded in the White Carpathian grasslands cannot be explained by a single factor. It results from a unique combination of regional factors (long history of these grasslands, large size of individual grassland areas and their existence in a landscape mosaic with forests, scrub and small wetlands), local abiotic factors (soil pH, soil nutrient status, moisture regime and resulting grassland productivity that are suitable for many species from the regional species pool) and management (low fertilizer input and mowing once a year in late spring or summer).
Former studies demonstrated that the river loach species Lefua sp. and Lefua echigonia (Nemacheilidae) have thin white linear markings from the pectoral fin base to the ventral fin base on both right and left sides of the abdomen that can be used to identify individuals in laboratory and in the field. In the present study we demonstrate the existence of such markings and the uniqueness of their shape in reared individuals of a further six species of Nemacheilidae, but found them absent in three species of Balitoridae. Furthermore, the long-term stability of the shape of the markings was examined in reared individuals of the nemacheilid Barbatula toni over two years. The white line markings offer a non-invasive tool for the individual recognition of nemacheilid species, some of which are threatened with extinction.
Many insects masquerade as parts of plants, such as bark or leaves, or mimic poisonous organisms in order to defend themselves against predators. However, recent studies indicate that plants may mimic insects and other arthropods to deter herbivores. Here, I report visually similar white structures of plants and arthropods in Japan and suggest they are part of a mimicry complex. Young shoots covered with white trichomes or waxy substances may mimic wax-producing insects, such as woolly aphids, coccids and caterpillars, potentially resulting in reduced herbivory. Since wax-producing insects would reduce plant quality and quantity, be distasteful and attract natural enemies, herbivorous insects and mammals may avoid such white shoots. Furthermore, fungus-infected insects, gregarious braconid cocoons, spider egg sacs and froth made by froghopper nymphs or blasticotomid sawfly larvae are also conspicuously white and impose risks for herbivorous insects. Thus, these white structures may be mimicry models for white shoots and are likely to be part of a defensive mimicry complex. Although this study focuses on defence against herbivores, there are simultaneous physiological roles for white colouration that will not be discussed in depth here., Kazuo Yamazaki., and Obsahuje bibliografii
White-tailed deer were introduced into the Czech Republic about one hundred years ago. Population numbers have remained stable at low density despite almost no harvesting. This differs from other introductions of this species in Europe. We presumed that one of the possible factors preventing expansion of the white-tailed deer population is lack of high-quality food components in an area overpopulated by sympatric roe, fallow and red deer. We analyzed the WTD winter diet and diets of the other deer species to get information on their feeding strategy during a critical period of a year. We focused primarily on conifer needle consumption, a generally accepted indicator of starvation and on bramble leaves as an indicator of high-quality items. We tested the following hypotheses: (1) If the environment has a limited food supply, the poorest competitors of the four deer species will have the highest proportion of conifer needles in the diet ; (2) the deer will overlap in trophic niches and will share limited nutritious resource (bramble). White-tailed, roe, fallow, and red deer diets were investigated by microscopic analysis of plant remains in their faeces. The volume of bramble decreased in the diet of all four deer species from November to March. The content of conifer needles in the diet of white-tailed and roe deer was negatively correlated with bramble and in spring made up 90 % of their diet volume. On the other hand conifer needles in the diet of red and fallow deer occurred only in January with snow cover. Fallow and red deer started the compensation of winter starvation at least one monthearlier than both roe and white-tailed deer. a high content of conifers in white-tailed deer diet in the second half of the winter fully support the presumption about low nutritional food supply and its diet. It can lead to a markedly impaired condition for white-tailed and roe deer and negatively affect their condition. The dietary overlap of four sympatric deer species was extensive in winter. All species share a limited good quality food supply (bramble) when food is scarce, suggesting that interspecific competition may occur.
This article analyses recent developments in Croatian housing finance to update the established account of housing finance and peripheral financialisation in Eastern Europe that is based on the boom-bust cycle of the 2000s and early-to-mid 2010s. During the bust stage of that cycle, changes in regulation and in the behaviour of debtors and creditors resulted in deleveraging and a shift away from the risky and exploitative lending practices characteristic of peripheral housing finance. However, new increases in household debt and housing prices since 2016–17, coupled with the COVID-19 pandemic, seem to have reversed these trends. While a boom-bust cycle of similar scope and modality to the first one is unlikely to be repeated, peripheral forms of housing finance have persisted to some degree.