Silvabase: A flexible data file management system

The need for a more flexible and efficient data file management system for mission planning in the Mission Operations Laboratory (EO) at MSFC has spawned the development of Silvabase. Silvabase is a new data file structure based on a B+ tree data structure. This data organization allows for efficient forward and backward sequential reads, random searches, and appends to existing data. It also provides random insertions and deletions with reasonable efficiency, utilization of storage space well but not at the expense of speed, and performance of these functions on a large volume of data. Mission planners required that some data be keyed and manipulated in ways not found in a commercial product. Mission planning software is currently being converted to use Silvabase in the Spacelab and Space Station Mission Planning Systems. Silvabase runs on a Digital Equipment Corporation's popular VAX/VMS computers in VAX Fortran. Silvabase has unique features involving time histories and intervals such as in operations research. Because of its flexibility and unique capabilities, Silvabase could be used in almost any government or commercial application that requires efficient reads, searches, and appends in medium to large amounts of almost any kind of data

DNA methylation epigenetically silences crossover hot spots and controls chromosomal domains of meiotic recombination in Arabidopsis.

During meiosis, homologous chromosomes undergo crossover recombination, which is typically concentrated in narrow hot spots that are controlled by genetic and epigenetic information. Arabidopsis chromosomes are highly DNA methylated in the repetitive centromeres, which are also crossover-suppressed. Here we demonstrate that RNA-directed DNA methylation is sufficient to locally silence Arabidopsis euchromatic crossover hot spots and is associated with increased nucleosome density and H3K9me2. However, loss of CG DNA methylation maintenance in met1 triggers epigenetic crossover remodeling at the chromosome scale, with pericentromeric decreases and euchromatic increases in recombination. We used recombination mutants that alter interfering and noninterfering crossover repair pathways (fancm and zip4) to demonstrate that remodeling primarily involves redistribution of interfering crossovers. Using whole-genome bisulfite sequencing, we show that crossover remodeling is driven by loss of CG methylation within the centromeric regions. Using cytogenetics, we profiled meiotic DNA double-strand break (DSB) foci in met1 and found them unchanged relative to wild type. We propose that met1 chromosome structure is altered, causing centromere-proximal DSBs to be inhibited from maturation into interfering crossovers. These data demonstrate that DNA methylation is sufficient to silence crossover hot spots and plays a key role in establishing domains of meiotic recombination along chromosomes.We thank Korbinian Schneeberger and Beth Rowan for advice implementing TIGER and Ler polymorphism data, Donna Bond for pJawohl-Act2, Quentin Gouil for the bisulfite sequencing protocol, Simon Andrews and Felix Krueger for advice using SeqMonk, Gregory Copenhaver and Avi Levy for fluorescent lines, Raphael Mercier for zip4-2 fancm-1, Chris Franklin for the ASY1 antibody, and the Gurdon Institute Imaging Facility for access to microscopes. Research was supported by a Broodbank Fellowship (to N.E.Y.), a Royal Society University Research Fellowship (to I.R.H.), grant GAT2962 from the Gatsby Charitable Foundation (to I.R.H.), and Biotechnology and Biological Sciences Research Council grant BB/L006847/1 (to I.R.H.).This is the final version of the article. It first appeared from Cold Spring Habour Laboratory Press via http://dx.doi.org/10.1101/gad.270876.11

Aggregation of chromosome axis proteins on the chromatin and in the nucleoplasm of Brassica oleracea meiocytes

Meiotic recombination is essential for the generation of genetic diversity in natural and breeding context. The chromosome axis comprises cohesin, HORMA-domain containing proteins and coiled coil proteins and is crucial for the establishment of meiotic recombination. These proteins form a complex during meiosis of Brassica oleracea but information about their respective localisation and dynamic on meiotic chromosomes remain sparse. Our study reveals that the HORMA-protein ASY1 aggregates on the chromatin and forms domains of high and low abundances. The regions enriched for ASY1 are also highly enriched for the axis proteins ASY3, SMC3 and SCC3, although to varying degrees between leptotene and pachytene stages. At later stages, when most DNA double strand breaks are repaired and the chromosome axis disassemble, ASY1, ASY3, SCC3 and SMC3 co-localise and form large aggregates on the discontinuous axis structures. As the axis structures reduce in length, we found that all four axis proteins relocalise in the nucleoplasm and further aggregates. Moreover, we found that ZYP1, the transverse filament of the synaptonemal complex, forms numerous chromosomic aggregates that are sometimes associated with MLH1 and can form ectopic synaptic interactions. Overall, our study indicates that axis proteins have a high propensity to aggregate. This property is important for assembling the chromosome axis but the association of axis proteins with the chromatin must be tightly regulated to limit polycomplex formation

Päästeameti pädevus ja ülesanded ohuolukorras varjumise korraldamisel elanike kaitseks

https://www.ester.ee/record=b536220

Rewiring Meiosis for Crop Improvement.

Meiosis is a specialized cell division that contributes to halve the genome content and reshuffle allelic combinations between generations in sexually reproducing eukaryotes. During meiosis, a large number of programmed DNA double-strand breaks (DSBs) are formed throughout the genome. Repair of meiotic DSBs facilitates the pairing of homologs and forms crossovers which are the reciprocal exchange of genetic information between chromosomes. Meiotic recombination also influences centromere organization and is essential for proper chromosome segregation. Accordingly, meiotic recombination drives genome evolution and is a powerful tool for breeders to create new varieties important to food security. Modifying meiotic recombination has the potential to accelerate plant breeding but it can also have detrimental effects on plant performance by breaking beneficial genetic linkages. Therefore, it is essential to gain a better understanding of these processes in order to develop novel strategies to facilitate plant breeding. Recent progress in targeted recombination technologies, chromosome engineering, and an increasing knowledge in the control of meiotic chromosome segregation has significantly increased our ability to manipulate meiosis. In this review, we summarize the latest findings and technologies on meiosis in plants. We also highlight recent attempts and future directions to manipulate crossover events and control the meiotic division process in a breeding perspective

Sense of balance? Nachhaltigkeitspolitische Fragen an die Distributed Ledger Technologie und Smart Contract Systeme

Distributed ledger technology and the development of digital smart contracts have the potential for a new disruptive technology. Applications based on them could find their way into the management of many areas of every day life. However, they also carry certain risks for sustainable development of our society. This paper is intended as a preliminary consideration and outlines some of these risks. - Die Distributed Ledger Technologie und die damit zusammenhängende Entwicklung von digitalen Smart Contracts bieten das Potential zu einer neuen disruptiven Technologie. Sie könnten Einzug in die Verwaltung vieler Lebensbereiche halten. Hier liegen neben Chancen auch deutliche Risiken für die nachhaltige Entwicklung

Investigating the interplay between chromosome axes and homologous recombination in arabidopsis meiosis

During meiosis and mitosis, the chromatin is organised stochastically in loop arrays. The formation and stabilisation of chromatin loop arrays is dependent on both cohesin and condensin but independent on the presence of a chromosome axis. The meiotic chromosome axes differ significantly from the mitotic axes. Components of the meiotic chromosome axes are thought to localise on the chromatin during S-phase and G2 in budding yeast and Arabidopsis, respectively, and promote the formation of meiotic DNA double-strand breaks (DSBs). In addition, several evidences suggest that the chromosome axes are required for the repair of SPO11-dependent DSBs off the sister. The status of the meiotic axes may also have an important role in the designation of future crossover sites and crossover interference. However, the composition of the chromosome axes, the regulation of its morphology and its function during meiosis are poorly understood in plants. The aims of this study consisted at further investigating the function of the axis-associated protein AtASY1 during DSB formation and DSB repair. The interaction between AtASY1 and the structural axis component AtASY3 was tested. In addition, the interplay between chromosome axes and the localisation of the AtSPO11-accessory protein AtPRD3 was analysed. This study showed that the formation of meiotic DSBs is spatially and temporally regulated by the formation of a nascent axis in Arabidopsis. The formation of the axes was independent on the formation of DSBs. However, the repair of DSBs off the sister and the formation of inter-homologue crossovers led to the remodelling of the axes in a pathway dependent on AtPCH2, an AAA ATPase family member. In addition, the phosphorylation level of AtASY1 T295 was increased in response to DSB formation. These highlight the coordination between the formation of DSBs/progression of DSB repair by homologous recombination and the remodelling of the chromosome axes

Ökologische Lebensstil-Avantgarden. Eine kurze Analyse sozialökologischer Gemeinschaften und ihres Innovationspotenzials

Subject of the study are intentional communities with a strong emphasis on sustainable development. The study explores ecovillages and other socio-ecological communities in their role as lifestyle avant-gardes and as pioneers of sustainable development. Main interest is both the sustainability and the innovation potential of such communities. Chap. 1 provides a brief overview of the history of the ecovillage movement - not only, but especially the German movement. Chap. 2 uses international research to evaluate whether intentional communities live up to their ecological and social aspirations. In addition, a quantitative analysis of 129 communities situated in the German Sprachraum analyzes age, gender composition, consumption habits, preferred organisational structures and main areas of activity. Chap. 3 gives an overview of important functional properties. Chap. 4 discusses the social appeal, describes limitations of the approach and shows for which population groups a communal way of life is not a suitable lifestyle model. Chap. 5 gives policy recommendations

IR Barcode Reader

BrandWatch Technologies is a company based in Portland, Oregon that seek to detect counterfeit products in the supply chain. BrandWatch has created a taggant material, a physical marker, that can be printed over barcodes or added to the ink used to print the barcodes themselves. This material, while invisible to the naked eye, is detectable using technology that they have developed. BrandWatch enlisted the help of a four man team of Cal Poly Mechanical Engineering students to combine this technology with that of a barcode scanner. The device, capable of scanning barcodes, detecting the presence of the taggant material, and relaying this information to the user is the end result of this project. The device is easily modifiable to request a taggant read or barcode scan first. A user simply has to pull the trigger and is walked through the process of scanning and reading via LCD screen prompts on the back of the handheld device. The data collected (both barcode and the presence of the taggant) is stored in a csv file on a small USB drive on the back of the device. This can easily be removed to transfer the data to a computer at the end of a work day