63 research outputs found
Klimatologija događaja magle na zračnoj luci Zagreb
This work presents a comprehensive study of climatology of fog events at Zagreb Airport. The data used in the study consists of observations from 1994 to 2015, in form of METAR reports. Fog events are classified into five types based on the physical mechanism of formation. The results show a decrease in the annual number of fog events at Zagreb Airport during the last 22 years. Fog is more frequent in the period between September and February, which can be designated as fog season. During spring and summer fog is a relatively rare phenomenon. Fog is usually quite dense; events with a minimum visibility of over 200 m occurred in only 29% of cases. Radiation fog is the dominant type of fog. The analysis has also shown that advective fog is very rare during summer, while precipitation fog and cloud base lowering fog occur only during fall and winter. All fog types except evaporation fog have a similar distribution of duration. Radiation fog and advective fog are the densest types; precipitation fog is the least dense type. A closer analysis of radiation fog has provided data on the annual/diurnal distribution of frequencies of onset and dissipation, wind during onset or dissipation, and persistence.U ovom radu opsežno je predstavljena klimatologija događaja magle na zračnoj luci Zagreb. U radu su korišteni podaci iz METAR izvještaja, u razdoblju od 1994. do 2015. Događaji magle su klasificirani u pet vrsta prema fizikalnom mehanizmu nastanka. Rezultati pokazuju smanjenje godišnjeg broja događaja magle na zračnoj luci Zagreb u protekle 22 godine. Magla je češća u razdoblju između rujna i veljače, koje se može nazvati sezonom magle. Za vrijeme proljeća i ljeta pojava magle je relativno rijetka. Magla je obično prilično gusta; događaji s minimalnom vidljivošću većom od 200 m čine samo 29% slučajeva. Prevladavajuća vrsta magle je radijacijska. Analiza pokazuje da je advektivna magla vrlo rijetka za vrijeme ljeta, dok oborinska magla i magla spuštanja podnice oblaka nastaju samo u jesen i zimi. Sve vrste magle, osim magle isparavanja, imaju sličnu raspodjelu trajanja. Radijacijska i advektivna magla su najgušće vrste; oborinska magla je najmanje gusta. Pomnija analiza radijacijske magle pružila je podatke o godišnjoj/dnevnoj raspodjeli učestalosti početka i završetka događaja magle, vjetra za vrijeme početka i završetka te perzistencije
Reversibility of Membrane N-Glycome of HeLa Cells upon Treatment with Epigenetic Inhibitors
Glycans are essential regulators of protein function and are now in the focus of research in many physiological and pathophysiological processes. There are numerous modes of regulating their biosynthesis, including epigenetic mechanisms implicated in the expression of glyco- genes. Since N-glycans located at the cell membrane define intercellular communication as well as a cellular response to a given environment, we developed a method to preferentially analyze this fraction of glycans. The method is based on incorporation of living cells into polyacrylamide gels, partial denaturation of membrane proteins with 3 M urea and subsequent release of N-glycans with PNGase F followed by HPLC analysis. Using this newly developed method, we revealed multiple effects of epigenetic inhibitors Trichostatin A, sodium butyrate and zebularine on the composition of N- glycans in human cells. The induced changes were found to be reversible after inhibitor removal. Given that many epigenetic inhibitors are currently explored as a therapeutic strategy in treatment of cancer, wherein surface glycans play an important role, the presented work contributes to our understanding of their efficiency in altering the N-glycan profile of cancer cells in culture
Glycomics meets genomics, epigenomics and other high throughput omics for system biology studies
Genome Editing Tools for Functional Analysis of HNF1A and IL6ST Genes
Genome editing tools, such as TALEN (transcription activator-like effector nuclease) or CRISPR-Cas9 (CRISPR-associated protein-9 nuclease) systems, enable functional studies by targeted gene knockout. They introduce double-stranded breaks (DSBs) into a DNA molecule in a sequence-specific manner, thereby stimulating the error-prone non-homologous end joining repair mechanism, leading to probable gene inactivation when the coding sequence is targeted. Vectors for expression of TALEN and Cas9-based constructs targeting the human IL6ST and HNF1A genes were assembled and tested for their ability to introduce DSBs when transfected into cultured cells using the luciferase assay. The Cas9-based construct targeting the IL6ST gene was shown to be active, while the two TALEN-based constructs did not introduce DSBs above background level. Both the TALEN and the CRISPR-Cas9 constructs targeting the HNF1A gene were found to be active, with the TALEN showing higher activity in a dose-dependent manner. The constructed genome-editing tools can be used for functional analysis of the putative role of HNF1A and IL6ST genes in IgG glycosylation, as shown previously by genome wide association studies.
This work is licensed under a Creative Commons Attribution 4.0 International License
Evolutional and clinical implications of the epigenetic regulation of protein glycosylation
Protein N glycosylation is an ancient posttranslational modification that enriches protein structure and function. The addition of one or more complex oligosaccharides (glycans) to the backbones of the majority of eukaryotic proteins makes the glycoproteome several orders of magnitude more complex than the proteome itself. Contrary to polypeptides, which are defined by a sequence of nucleotides in the corresponding genes, glycan parts of glycoproteins are synthesized by the activity of hundreds of factors forming a complex dynamic network. These are defined by both the DNA sequence and the modes of regulating gene expression levels of all the genes involved in N glycosylation. Due to the absence of a direct genetic template, glycans are particularly versatile and apparently a large part of human variation derives from differences in protein glycosylation. However, composition of the individual glycome is temporally very constant, indicating the existence of stable regulatory mechanisms. Studies of epigenetic mechanisms involved in protein glycosylation are still scarce, but the results suggest that they might not only be important for the maintenance of a particular glycophenotype through cell division and potentially across generations but also for the introduction of changes during the adaptive evolution
Profiling IgG N-glycans as potential biomarker of chronological and biological ages:A community-based study in a Han Chinese population
As an important post-translation modifying process, glycosylation significantly affects the structure and function of immunoglobulin G (IgG) molecules and is essential in many steps of the inflammatory cascade. Studies have demonstrated the potential of using glycosylation features of IgG as a component of predictive biomarkers for chronological age in several European populations, whereas no study has been reported in Chinese. Herein, we report various patterns of changes in IgG glycosylation associated with age by analyzing IgG glycosylation in 701 community-based Han Chinese (244 males, 457 females; 23-68 years old). Eleven IgG glycans, including FA2B, A2G1, FA2[6]G1, FA2[3]G1, FA2[6]BG1, FA2[3]BG1, A2G2, A2BG2, FA2G2, FA2G2S1, and FA2G2S2, change considerably with age and specific combinations of these glycan features can explain 23.3% to 45.4% of the variance in chronological age in this population. This indicates that these combinations of glycan features provide more predictive information than other single markers of biological age such as telomere length. In addition, the clinical traits such as fasting plasma glucose and aspartate aminotransferase associated with biological age are strongly correlated with the combined glycan features. We conclude that IgG glycosylation appears to correlate with both chronological and biological ages, and thus its possible role in the aging process merits further stud
Integrative epigenome-wide analysis demonstrates that DNA methylation may mediate genetic risk in inflammatory bowel disease
Epigenetic alterations may provide important insights into gene-environment interaction in inflammatory bowel disease (IBD). Here we observe epigenome-wide DNA methylation differences in 240 newly-diagnosed IBD cases and 190 controls. These include 439 differentially methylated positions (DMPs) and 5 differentially methylated regions (DMRs), which we study in detail using whole genome bisulphite sequencing. We replicate the top DMP (RPS6KA2) and DMRs (VMP1, ITGB2 and TXK) in an independent cohort. Using paired genetic and epigenetic data, we delineate methylation quantitative trait loci; VMP1/microRNA-21 methylation associates with two polymorphisms in linkage disequilibrium with a known IBD susceptibility variant. Separated cell data shows that IBD-associated hypermethylation within the TXK promoter region negatively correlates with gene expression in whole-blood and CD8+ T cells, but not other cell types. Thus, site-specific DNA methylation changes in IBD relate to underlying genotype and associate with cell-specific alteration in gene expression
Grafphic Novel: What comes with the Wind
Grafički roman Što donosi vjetar je autorska priča s kriminalističkim zapletom o životu i likovima na malenom jadranskom otoku. Naizgled miran i monoton život postaje sasvim drukčiji dolaskom troje turista na otok. Svi skrivaju tajnu i čini se da nitko nije osoba kojom se predstavlja. Međutim, zajedničkim snagama otočani uspijevaju riješiti misterije i pokazati da nitko ne može ugroziti njihovu malu otočku zajednicu.Graphic novel What Comes With the Wind is an original story about life and people on a small Adriatic island with elements of crime genre. Seemingly calm and uneventful life becomes something completely different when three tourists arrive. Everybody has a secret and it seems nobody is what they seem to be at first sight. Nevertheless, the islanders manage to solve mysteries working together and they show that nobody can jeopardize their small island community
Grafphic Novel: What comes with the Wind
Grafički roman Što donosi vjetar je autorska priča s kriminalističkim zapletom o životu i likovima na malenom jadranskom otoku. Naizgled miran i monoton život postaje sasvim drukčiji dolaskom troje turista na otok. Svi skrivaju tajnu i čini se da nitko nije osoba kojom se predstavlja. Međutim, zajedničkim snagama otočani uspijevaju riješiti misterije i pokazati da nitko ne može ugroziti njihovu malu otočku zajednicu.Graphic novel What Comes With the Wind is an original story about life and people on a small Adriatic island with elements of crime genre. Seemingly calm and uneventful life becomes something completely different when three tourists arrive. Everybody has a secret and it seems nobody is what they seem to be at first sight. Nevertheless, the islanders manage to solve mysteries working together and they show that nobody can jeopardize their small island community
Grafphic Novel: What comes with the Wind
Grafički roman Što donosi vjetar je autorska priča s kriminalističkim zapletom o životu i likovima na malenom jadranskom otoku. Naizgled miran i monoton život postaje sasvim drukčiji dolaskom troje turista na otok. Svi skrivaju tajnu i čini se da nitko nije osoba kojom se predstavlja. Međutim, zajedničkim snagama otočani uspijevaju riješiti misterije i pokazati da nitko ne može ugroziti njihovu malu otočku zajednicu.Graphic novel What Comes With the Wind is an original story about life and people on a small Adriatic island with elements of crime genre. Seemingly calm and uneventful life becomes something completely different when three tourists arrive. Everybody has a secret and it seems nobody is what they seem to be at first sight. Nevertheless, the islanders manage to solve mysteries working together and they show that nobody can jeopardize their small island community
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