113 research outputs found

    The antioxidant activity of selected species of small fruit

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    Diplomová práce se zabývá stanovením celkové antioxidační aktivity červených a bílých angreštů a červených, bílých a černých rybízů. V teoretické části jsou shrnuty dostupné informace o drobném ovoci, přehled přírodních a syntetických antioxidantů a souhrn použitých metod pro stanovení celkové antioxidační aktivity. Zmražené vzorky ovoce byly poskytnuty výzkumným a šlechtitelským ústavem ovocnářským Holovousy, s. r. o. v rámci projektu QI111A141 – Výzkum nových technologií v pěstování angreštu a rybízu se zaměřením na kvalitu a využití plodů (Ministerstvo zemědělství ČR). Celková antioxidační aktivita červených a bílých angreštů a rybízů byla změřena spektrofotometrickými metodami využívající volné radikály ABTS•+ a DPPH a byla vyjádřena jako ekvivalent látky Trolox. Černé rybízy byly proměřeny elektronovou paramagnetickou rezonancí s využitím volných radikálů ABTS•+ a DPPH a celková antioxidační aktivita byla vyjádřena hodnotami TEACABTS a TEACDPPH. Celkem bylo proměřeno 8 odrůd červených angreštů, 6 odrůd bílých angreštů, 12 odrůd červených rybízu, 6 odrůd bílých rybízu a 8 odrůd černých rybízů. Nejvyšší hodnoty celkové antioxidační aktivity vykazovaly odrůdy červených a bílých angreštů Alan, Karmen, Pax a Invicta a odrůdy červených a bílých rybízů Rovada, Orion a Olin. Mezi černými rybízy dosahovaly nejvyšší hodnoty celkové antioxidační aktivity odrůdy Ometa a Ruben.This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.

    Transboundary Cooperation: The Best Way to Share Common Responsibility for Future

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    The Bavarian Forest National Park (BFNP) and Šumava National Park (ŠNP), established in 1969 and 1991, respectively, are located between Prague and Munich. Their long common border accents the transboundary issue regarding nature conservation, ecological corridors and connectivity. Plans to protect this large forest landscape, dating back to the early twentieth century, were never implemented due to the two World Wars and Iron Curtain. Initially, there were many joint activities. Many common projects (e.g., joint information centre, transboundary public transport system, GPS lynx and deer telemetry) were conducted. Both sides have learned a lot during these 25 years of cooperation. The main obstacles in cooperation are economic differences between the regions, language barriers and different policies and laws. There is only one common ecosystem of mountain forests, common populations of lynx, capercaillie or bark beetle, and the partners have to learn how to share their common responsibility for the future. Step by step, the transboundary cooperation is improving, which is very important in good years, but maybe even more important in bad years. The principle stance of the transboundary partner can buffer threatening in the neighbouring national park and support recovery when the crisis is over

    Comparison of an analytical techniques for determination of an antioxidant activity in food

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    Tato bakalářská práce se zabývá charakteristikou přírodních a syntetických antioxidantů a jejich působením na volné radikály. Přírodní antioxidanty přijímáme většinou jako součásti složitých směsí, a proto se snažíme antioxidační aktivitu charakterizovat jako celek. Pro stanovení celkové antioxidační aktivity potravin byly vyvinuty chemické a fyzikální metody. Práce se soustředí na chemické metody, konkrétně na ABTS a DPPH, které jsou založeny na reakci antioxidantů se syntetickými radikály, a dále na metodu FRAP, která je založena na redukční schopnosti antioxidantů. V experimentální části jsou tyto metody porovnávány z hlediska jejich náročnosti a poskytnutých výsledků z analýz reálných vzorků potravin.This bachelor‘s thesis deals with the characterization of natural and synthetic antioxidants and their effects on free radicals. Natural antioxidants are usually absorbed as a part of complex mixtures and that’s why we try to characterize an antioxidant activity as a whole. Chemical and physical methods have been developed to determine the total antioxidant activity of food. This thesis focuses on chemical methods, specifically on ABTS and DPPH, which are based on a reaction of antioxidants with synthetic radicals. Next chemical method is FRAP, which is based on the reducing ability of antioxidants. In the experimental part, these methods are compared from a perspective of their performance and the results of the analysis of real food samples.

    Weaves and patterns of fabrics

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    Pharmacogenetic interaction between dexamethasone and Cd36-deficient segment of spontaneously hypertensive rat chromosome 4 affects triacylglycerol and cholesterol distribution into lipoprotein fractions

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    Dexamethasone (DEX) is known to induce diabetes and dyslipidemia. We have compared fasting triacylglycerol and cholesterol concentrations across 20 lipoprotein fractions and glucose tolerance in control (standard diet) and DEX-treated 7-month-old males of two rat strains, Brown Norway (BN) and congenic BN.SHR-(Il6-Cd36)/Cub (BN.SHR4). These two inbred strains differ in a defined segment of chromosome 4, originally transferred from the spontaneously hypertensive rat (SHR) including the mutant Cd36 gene, a known target of DEX. Compared to BN, the standard-diet-fed BN.SHR4 showed higher cholesterol and triacylglycerol concentrations across many lipoprotein fractions, particularly in small VLDL and LDL particles. Total cholesterol was decreased by DEX by more than 21% in BN.SHR4 contrasting with the tendency to increase in BN (strain*DEX interaction p = 0.0017). Similar pattern was observed for triacylglycerol concentrations in LDL. The LDL particle size was significantly reduced by DEX in both strains. Also, while control BN and BN.SHR4 displayed comparable glycaemic profiles during oral glucose tolerance test, we observed a markedly blunted DEX induction of glucose intolerance in BN.SHR4 compared to BN. In summary, we report a pharmacogenetic interaction between limited genomic segment with mutated Cd36 gene and dexamethasone-induced glucose intolerance and triacylglycerol and cholesterol redistribution into lipoprotein fractions

    The status of commons in the changing landscape in the Czech Republic

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    Commons were ancient pastures, which once occurred in every village in many countries, including the Czech Republic. They have been a landscape and social phenomenon for decades. However, social and economic changes brought an end to community ownership and traditional management of these commons. The number of commons has been decreasing since the middle of the 19th century and currently very few remain. This paper evaluates the status of former commons in 35 cadastres in south-western Bohemia and describes the changes they have undergone in the last two hundred years. Three historical periods were identified as the main drivers in the changes in the status of commons. We started with a period from the middle of the 19th century to the 1950s, the second from 1950s to 1990s and the last from 1990s to 2019. Aerial images and field surveys revealed that 93% of former commons disappeared due to afforestation, conversion to fields and natural succession occurring on abandoned commons. The social and economic aspects associated with these changes are mentioned. Some of the commons are part of the Territorial system of landscape ecological stability (Ecological networks) and we suggest that more of the remaining commons should be included in this network. They could play a role in maintaining biodiversity and providing stepping stones in a uniform agriculture landscape. We propose to evaluate the conservation and ecosystem value of these commons in more detail and set up the appropriate management essential for the preservation or restoration of commons, an indisputable part of our biological and cultural heritage

    Escherichia coli from biopsies differ in virulence genes between patients with colorectal neoplasia and healthy controls

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    IntroductionPathogenic strains of Escherichia coli have been clearly identified as the causative agents of extraintestinal and diarrheal infections; however, the etiopathogenic role of E. coli in other conditions, including colorectal cancer, remains unclear.MethodsThis study aimed to characterize mucosal E. coli isolates (n = 246) from 61 neoplasia patients and 20 healthy controls for the presence of 35 genetic determinants encoding known virulence factors.ResultsVirulence determinants encoding invasin (ibeA), siderophore receptor (iroN), S-fimbriae (sfa), and genotoxin (usp) were more prevalent among E. coli isolated from patients with neoplasia compared to the control group (p < 0.05). In addition, the prevalence of these virulence determinants was increased in more advanced neoplasia stages (padj < 0.0125). Compared to patients with advanced colorectal adenoma and carcinoma, the ibeA gene was rarely found in the control group and among patients with non-advanced adenoma (p < 0.05), indicating its potential as the advanced-neoplasia biomarker. Patients with neoplasia frequently had E. coli strains with at least one of the abovementioned virulence factors, whereby specific combinations of these virulence factors were found.DiscussionThese findings suggest that E. coli strains isolated from patients with colorectal neoplasia possess several virulence factors, which could contribute to the development of neoplastic processes in the large intestine

    Overexpression of Full-Length Centrobin Rescues Limb Malformation but Not Male Fertility of the Hypodactylous (hd) Rats

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    Rat hypodactyly (hd) mutation is characterized by abnormal spermatogenesis and sperm decapitation, limb malformation (missing digits II and III) and growth retardation. We have previously reported centrobin (centrosome BRCA2-interacting protein) truncation at the C-terminus in the hd mutant. Here, we report data from a transgenic rescue experiment carried out to determine a role of centrobin in pathogenesis of hd. The transgenic construct, consisting of full-length-coding cDNA linked to a ubiquitous strong promoter/enhancer combination, was inserted to chromosome 16 into a LINE repeat. No known gene is present in the vicinity of the insertion site. Transgenic centrobin was expressed in all tissues tested, including testis. Transgenic animals show normal body weight and limb morphology as well as average weight of testis and epididymis. Yet, abnormal spermatogenesis and sperm decapitation persisted in the transgenic animals. Western blotting showed the coexistence of full-length and truncated or partially degraded centrobin in sperm of the rescued transgenic animals. Immunocytochemistry showed a buildup of centrobin and ODF2 (outer dense fiber 2) at the sperm decapitation site in the hd mutant and rescued transgenic rats. Additional findings included bulge-like formations and thread-like focal dissociations along the sperm flagellum and the organization of multiple whorls of truncated sperm flagella in the epididymal lumen. We conclude that centrobin is essential for normal patterning of the limb autopod. Centrobin may be required for stabilizing the attachment of the sperm head to flagellum and for maintaining the structural integrity of the sperm flagellum. We postulate that the presence of truncated centrobin, coexisting with full-length centrobin, together with incorrect timing of transgenic centrobin expression may hamper the rescue of fertility in hd male rats

    High prevalence and genetic diversity of Treponema paraluisleporidarum isolates in European lagomorphs

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    The bacterium Treponema paraluisleporidarum causes syphilis in lagomorphs. In a set of 1,095 samples from four species—European brown hare, mountain hare, Corsican hare, and European rabbit—we tested for infection and genotyped the strains that infect wild lagomorphs. Samples originate from Sweden, the Netherlands, the United Kingdom, Germany, the Czech Republic, and Italy. The phylogenetic analyses of two informative gene targets (tp0488 and tp0548) showed high genetic diversity among the lagomorph-infecting treponemes. More specifically, we found a high number of nucleotide variants and various short repeat units in the tp0548 locus that have not been described for human syphilis and primate yaws causing Treponema pallidum. While the functional aspect of these short repeat units remains subject to ongoing investigations, it likely enables the pathogen to better survive in its lagomorph host. Our data did not support any geographic clustering, which is equally reflected in the host population genetics as shown by mitochondrial genome data corresponding to the sampled lagomorph populations. This is unexpected and in contrast with what has been shown for nonhuman primate infection with T. pallidum. In the future, the combination of multi-locus sequence typing and whole genome data from modern and ancient samples from a wide geographic range and multiple lagomorph species will contribute to a better understanding of the epidemiology and evolutionary path of lagomorph-infecting treponemes. In conclusion, our current study demonstrates widespread infection and a high genetic variation of the syphilis-causing pathogen in a higher number of positively PCR-tested European lagomorphs (n = 302/1,095)

    Quantitative Palynology Informing Conservation Ecology in the Bohemian/Bavarian Forests of Central Europe

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    In 1927, the first pollen diagram was published from the Bohemian/Bavarian Forest region of Central Europe, providing one of the first qualitative views of the long-term vegetation development in the region. Since then significant methodological advances in quantitative approaches such as pollen influx and pollen-based vegetation models (e.g., Landscape Reconstruction Algorithm, LRA) have contributed to enhance our understanding of temporal and spatial ecology. These types of quantitative reconstructions are fundamental for conservation and restoration ecology because they provide long-term perspectives on ecosystem functioning. In the Bohemian/Bavarian Forests, forest managers have a goal to restore the original forest composition at mid-elevation forests, yet they rely on natural potential vegetation maps that do not take into account long-term vegetation dynamics. Here we reconstruct the Holocene history of forest composition and discuss the implications the LRA has for regional forest management and conservation. Two newly analyzed pollen records from Prášilské jezero and Rachelsee were compared to 10 regional peat bogs/mires and two other regional lakes to reconstruct total land-cover abundance at both the regional- and local-scales. The results demonstrate that spruce has been the dominant canopy cover across the region for the past 9,000 years at both high- (>900 m) and mid-elevations (>700–900 m). At the regional-scale inferred from lake records, spruce has comprised an average of ~50% of the total forest canopy; whereas at the more local-scale at mid-elevations, spruce formed ~59%. Beech established ~6,000 cal. years BP while fir established later around 5,500 cal. years BP. Beech and fir growing at mid-elevations reached a maximum land-cover abundance of 24% and 13% roughly 1,000 years ago. Over the past 500 years spruce has comprised ~47% land-cover, while beech and fir comprised ~8% and <5% at mid-elevations. This approach argues for the “natural” development of spruce and fir locally in zones where the paleoecology indicates the persistence of these species for millennia. Contrasting local and regional reconstructions of forest canopy cover points to a patchwork mosaic with local variability in the dominant taxa. Incorporation of paleoecological data in dialogues about biodiversity and ecosystem management is an approach that has wider utility
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