The impact of chromatin modifiers on the timing of locus replication in mouse embryonic stem cells

A panel of mutant embryonic stem (ES) cell lines lacking important chromatin modifiers was used to dissect the relationship between chromatin structure and replication timing, revealing the importance of several chromatin modifiers for maintaining correct replication of satellite sequences in pluripotent ES cells

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Zircons from Collisional Granites, Garhwal Himalaya, NW India: U–Th–Pb Age, Geochemistry and Protolith Constraints

In the present work, we studied zircons from the less foliated granites of the Chail Group, which form a thrust sheet of the Lesser Himalayan Sequences, Garhwal region. Compositionally, these granites are S–type, formed in a collisional tectonic setting. Zircons possess an internal structure, mineral inclusions, and geochemical characteristics typical of magmatic origin. The U–Th–Pb geochronology and geochemistry were assessed using the laser ablation multi–collector inductively coupled plasma spectrometry (LA–ICP–MS) technique. U–Th–Pb isotope dating of zircons from two different samples revealed their age, estimated from the upper intersection of the discordia, to be 1845 ± 19 Ma. Zircons from one sample contained inherited cores belonging to three age groups: Paleoarchean (3.52 Ga), Neoarchean (2.78 Ga and 2.62 Ga), and Paleoproterozoic (2.1 Ga). Zircons with ages of 3.52, 2.62, and 2.1 Ga were interpreted as magmatic based on their geochemical characteristics. The 2.78 Ga core was interpreted as metamorphic. The observed inheritance is consistent with the melting of sedimentary rocks. The inherited zircons could have originated from Aravalli and Bundelkhand Craton and Paleoproterozoic Aravalli Fold Belt rocks. This confirms that the studied granites are S–type and could have been formed in a collisional environment at 1.85 Ga on the western flank of the Columbia Supercontinent

Morphological Analysis of Poly(4,4′-oxydiphenylene-pyromellitimide)-Based Organic Solvent Nanofiltration Membranes Formed by the Solution Method

Poly-(4,4′-oxydiphenylene) pyromellitimide or Kapton is the most widely available polyimide with high chemical and thermal stability. It has great prospects for use as a membrane material for filtering organic media due to its complete insolubility. However, the formation of membranes based on it, at the moment, is an unsolved problem. The study corresponds to the rediscovery of poly(4,4′-oxydiphenylene–pyromellitimide)-based soluble copoly(urethane-imides) as membrane polymers of a new generation. It is shown that the physical structure of PUI films prepared by the solution method becomes porous after the removal of urethane blocks from the polymer, and the pore size varies depending on the conditions of thermolysis and subsequent hydrolysis of the membrane polymer. The film annealed at 170 °C with a low destruction degree of polycaprolactam blocks exhibits the properties of a nanofiltration membrane. It is stable in the aprotic solvent DMF and has a Remasol Brilliant Blue R retention coefficient of 95%. After the hydrolysis of thermally treated films in acidic media, ultrafiltration size 66–82 nm pores appear, which leads to an increase in the permeate flow by more than two orders of magnitude. This circumstance provides opportunities for controlling the membrane polymer structure for further optimization of the performance characteristics of filtration membranes based on it. Thus, we proposed a new preparation method of ultra- and nanofiltration membranes based on poly(4,4′-oxydiphenylene–pyromellitimide) that are stable in aprotic solvents

Satellite replication in ES cells is altered by mutation of chromatin modifiers

Summary of replication timing of repeat sequences in mutant ES cell lines. Top, ideogram of the acrocentric mouse chromosome X, showing the position of minor satellite (Minor sat), major satellite (Major sat) and the X-linked X141 repeat. Examples show replication timing of repeats in wild type (WT, white bars (OS25 for Mll, Eed and Dnmt1; matched wild-type lines for G9a, Suv39 h1/h2 and Dicer)) compared to ES cells mutant for the indicated chromatin modifier (black bars). The mean values and standard error of at least two (two to five) independent experiments are shown.<p><b>Copyright information:</b></p><p>Taken from "The impact of chromatin modifiers on the timing of locus replication in mouse embryonic stem cells"</p><p>http://genomebiology.com/2007/8/8/R169</p><p>Genome Biology 2007;8(8):R169-R169.</p><p>Published online 17 Aug 2007</p><p>PMCID:PMC2374999.</p><p></p

Replication timing of repetitive elements in wild-type and mutant ES cell lines

The replication timing was determined for retrotransposons (LINE and SINE B1) and rDNA repeats in wild-type OS25 ES cells and in mutant ES cells lacking Eed, Dnmt 1, Dnmt 3a/3b, G9a or Dicer. The mean values and standard error of at least two independent experiments are shown.<p><b>Copyright information:</b></p><p>Taken from "The impact of chromatin modifiers on the timing of locus replication in mouse embryonic stem cells"</p><p>http://genomebiology.com/2007/8/8/R169</p><p>Genome Biology 2007;8(8):R169-R169.</p><p>Published online 17 Aug 2007</p><p>PMCID:PMC2374999.</p><p></p

Amino acid formulas in patients with food allergy

The article presents modern approaches to the use of balanced formulas for nutrition and diet correction in children with various forms of food allergies. The guidelines are based on all available up to date evidence on the efficacy, safety and utility of using such innovative medical technology as specialized amino acid formulas. This formula is the targeted medical intervention for food allergies and confirmed cow's milk protein allergy, and particularly for patients with reduced physical growth and development (growth rates included). The material is based on methodological guidelines on the amino acid formulas usage previously developed by specialist experts of the Union of pediatricians of Russia in 2020

Amino Acid Formulas in Patients with Gastrointestinal Diseases

Modern approaches for the management of children with gastrointestinal pathologies include optimal nutritional support that makes it possible to replete energy failure and restore essential nutrients balance. The article presents key information on gastrointestinal diseases in which modern amino acid formulas can be used to regulate nutritional status. The authors have conducted the extensive analysis of all available for now evidence on the efficacy, safety and utility of using such innovative medical technology as special elemental formula in gastrointestinal tract pathological conditions. This material is the basis for guidlines on the use of amino acid formulas developed by expert specialists of the Union of Pediatricians of Russia in 2020