Characterization and first results of the planetary borehole-wall imager – methods to develop for in-situ exploration

Prototypes of borehole-wall imager instruments were developed and tested at a desert riverbed in Morocco and at a lake’s salty flat in the Atacama desert, to support the drilling activity of ExoMars rover. The onsite recorded borehole images contain information on the context that are lost during the sample acquisition. Benefits of the borehole-wall imaging is the easier maximal energy estimation of a fluvial flow, the detailed information on sedimentation and layering, especially the former existence of liquid water and its temporal changes, including paleo-flow direction estimation from grain imbrication direction. Benefits of laboratory analysis of the acquired samples are the better identification of mineral types, determination of the level of maturity of granular sediment, and identification of the smallest, wet weathered grains. Based on the lessons learned during the comparison of field and laboratory results, we demonstrate that recording the borehole-wall with optical instrument during/after drilling on Mars supports the paleo-environment reconstruction with such data that would otherwise be lost during the sample acquisition. Because of the lack of plate tectonism and the low geothermal gradient on Mars, even Ga old sediments provide observable features that are especially important for targeting Mars sample return and later crewed Mars missions

Human p53 interacts with the elongating RNAPII complex and is required for the release of actinomycin D induced transcription blockage

The p53 tumour suppressor regulates the transcription initiation of selected genes by binding to specific DNA sequences at their promoters. Here we report a novel role of p53 in transcription elongation in human cells. Our data demonstrate that upon transcription elongation blockage, p53 is associated with genes that have not been reported as its direct targets. p53 could be co-immunoprecipitated with active forms of DNA-directed RNA polymerase II subunit 1 (RPB1), highlighting its association with the elongating RNA polymerase II. During a normal transcription cycle, p53 and RPB1 are localised at distinct regions of selected non-canonical p53 target genes and this pattern of localisation was changed upon blockage of transcription elongation. Additionally, transcription elongation blockage induced the proteasomal degradation of RPB1. Our results reveal a novel role of p53 in human cells during transcription elongation blockage that may facilitate the removal of RNA polymerase II from DNA

Human p53 interacts with the elongating RNAPII complex and is required for the release of actinomycin D induced transcription blockage

The p53 tumour suppressor regulates the transcription initiation of selected genes by binding to specific DNA sequences at their promoters. Here we report a novel role of p53 in transcription elongation in human cells. Our data demonstrate that upon transcription elongation blockage, p53 is associated with genes that have not been reported as its direct targets. p53 could be co-immunoprecipitated with active forms of DNA-directed RNA polymerase II subunit 1 (RPB1), highlighting its association with the elongating RNA polymerase II. During a normal transcription cycle, p53 and RPB1 are localised at distinct regions of selected non-canonical p53 target genes and this pattern of localisation was changed upon blockage of transcription elongation. Additionally, transcription elongation blockage induced the proteasomal degradation of RPB1. Our results reveal a novel role of p53 in human cells during transcription elongation blockage that may facilitate the removal of RNA polymerase II from DNA

Az ImaGeo-magszkennelés módszerei egy mecseki fúrás nagy felbontású értelmezésének példáján = Methods of ImaGeo Corescanning and a case study of a high resolution borehole evaluation from the Mecsek Mountains

A saját fejlesztésű ImaGeo-rendszer terepen, fúrásokban és bányatérségekben is nagy felbontású, digitális földtani dokumentációt és 3D földtani–tektonikai adatfelvételt tesz lehetővé, normál és UV-fény megvilágításban egyaránt. A fúrásokban kapott adatok mélyfúrás-geofizikai akusztikus (Borehole televiewer, BHTV) vagy ellenállás (pl. Formation MicroImager, FMI) adatsorok felhasználásával újra orientálhatóak és ezzel részletes földtani elemzések megvalósítása vá liklehetővé a valós térben. A rendszer részei a Magszkenner, a Fotórobot és a LIPS (Lézergerjesztésű plazmaspektrométer). Jelen cikk az ImaGeo-rendszer módszereinek bemutatása mellett esettanulmányt közöl az Ibafa, Ib–4 fúrás mezo -zoos rétegsorának magszkenneléses eredményeiről különös tekintettel a Jakabhegyi Homokkő Formáció elemzésére. A Formáció vizsgálatát az adatok 45/13°-os (dőlésirány/dőlésszög) tektonikusan kibillentett helyzetből történt visszabillentés után valósítottuk meg. A magszkennelésből származó szemcseméret-, rétegvastagság-, dőlésirány-és dőlésszögeloszlások vizsgálata alapján a Jakabhegyi Homokkő Formáció harántolt rétegsorát 5 szakaszra lehetett bontani. A szakaszhatárok nem korrelálnak a földtani dokumentáció szakaszainak határaival. A visszabillentett dőlések D-DK, D és DNy felé mutatnak, de bizonyos mélységszakaszokban a tisztán Ny-i és K-i irányok is jelentősek. Mindezeket üledékszállítási főirányként értelmezzük. A szállítási irányok a formáció egészét tekintve is széles spektrumon oszlanak el. A rétegvastagság, dőlésirány-és dőlésszögadatok ciklicitás-elemzését vizuálisan, mintázatok felismerése útján és geomatematikai periodicitáselemzéssel vizsgáltuk. Ezek alapján több, különböző periódushosszúságú (deciméteres, 1,3 és 8 méteres) ciklust lehetett meghatározni. A ciklusosság megállapítható a lemezvastagságban, a dőlésszögek és a dőlésirányok eloszlásában is. A hosszabb ciklusok leginkább a dőlésirányok eloszlásában mutatkoznak. A dőlésszögekben a vizuális, mintázatokon alapuló és a geomatematikai módszer is a 0,5 m körüli ciklust mutatta ki. A geomatematikai elemzés 2 párhuzamos ciklushosszt mutatott ki a dőlésirányokban és a dőlésszögekben. Ezek 1,3 és ~ 4,5 m ciklushosszúságú periódusok. A vizuális elemzés feltárt egy mintegy 50 m-es ciklust is, ezt geomatematikai úton nem lehetett igazolni

Characterization and first results of the planetary borehole-wall imager — methods to develop for in-situ exploration

Prototypes of borehole-wall imager instruments were developed and tested at a desert riverbed in Morocco and at a lake’s salty flat in the Atacama desert, to support the drilling activity of ExoMars rover. The onsite recorded borehole images contain information on the context that are lost during the sample acquisition. Benefits of the borehole-wall imaging is the easier maximal energy estimation of a fluvial flow, the detailed information on sedimentation and layering, especially the former existence of liquid water and its temporal changes, including paleo-flow direction estimation from grain imbrication direction. Benefits of laboratory analysis of the acquired samples are the better identification of mineral types, determination of the level of maturity of granular sediment, and identification of the smallest, wet weathered grains. Based on the lessons learned during the comparison of field and laboratory results, we demonstrate that recording the borehole-wall with optical instrument during/after drilling on Mars supports the paleo-environment reconstruction with such data that would otherwise be lost during the sample acquisition. Because of the lack of plate tectonism and the low geothermal gradient on Mars, even Ga old sediments provide observable features that are especially important for targeting Mars sample return and later crewed Mars missions

Magas inert tartalmú és biogázok tüzelési tulajdonságainak vizsgálata = Investigation of Combustion Properties of High Inert Gases and Biogases

A kutatási projekt első évében feltérképezésre kerülek főbb európai biogáz források. Egyik típus a biológiai bomlással előállított, vagy deponia gázok, ezek tipikus összetétele 60% CH4. A másik a termikus bontással előállított úgynevezett pirolízis gázok. A biomasszát elgázosíthatjuk anaerob úton, aerob úton levegővel, vagy tiszta oxigénnel. Az összehasonlító vizsgálatokat ezzel a négy típusgázzal és a referencia földgázzal végeztük. A GRI 3.0 mechanizmus segítségével modelleztük a kiválasztott gázok égése során kialakuló lángterjedési sebességeket és az adiabatikus lánghőmérsékleteket. Kialakítottuk a mérőrendszert vizsgálatokra. A Schlieren rendszer segítségével elkészül képek alapján meghatározzuk az szögeltérüléseket. A gázok égési folyamatiról CFD számításokat végeztünk, majd az eredményekből szintén számítással meghatároztuk az szögeltérüléseket. Így a CFD számítások ellenőrzésére is lehetőség van. Az elkészült mérőrendszernek másik eleme a lángspectrométer, segítségével mérhetők lángokban létrejövő különböző rövidéletű gyökök a lángsugárzás hullámhossz szerinti összetételének mérésével. A láng ionizáció egy adott térfogatban a vezetőképesség mérésével követhető, amely az égés során létrejövő rövidéletű gyökökre vezethető vissza. Ennek a lángon belüli vizsgálatára alakítottuk ki a lángionizációs mérőberendezésünket. A méréseket elvégeztük mind az öt gázzal, a mérési eredményekről internetes katalógust alakítottunk ki. | IIn beginig of this project the European biogas types and sources were determined. There are biogases which were made by biodegradation and deposit gases. The typical composition of these gases is: 60% CH4 and 40% CO2. And there are so called pyrolysis gases which were made by thermo degradation. Biomass can be gasified anaerobe or aerobe way with air or with oxygen. The comparative analysis was made with this four gas type and reference gas. The adiabatic flame temperature and laminar flame velocity of these gases was modelled by the GRI 3.0 mechanism. The measuring system was installed for the investigations. The angular deflections were determined from the Schlieren pictures. CFD calculations were made from the combustion process of these gases, and the angular deflections were determined from these calculations too, so CFD calculations can be validated. The other unit of the installed measuring system is the flame spectrophotometer. The radical composition of the flame can be determined by the flame emission spectroscopy at different condition of combustion. The flame ionisation is detectable by the measurement of the conductivity in a given volume, which is caused by the radicals in the flame. For the measurement of the flame ionisation the flame ionisation measuring system was installed. From the results was made a catalogue on the internet. Presently there are measurements with the aerobe pyrolysis gas and natural gas mixtures in gas engine

UVB Induces a Genome-Wide Acting Negative Regulatory Mechanism That Operates at the Level of Transcription Initiation in Human Cells

International audienceFaithful transcription of DNA is constantly threatened by different endogenous and environmental genotoxic effects. Transcription coupled repair (TCR) has been described to stop transcription and quickly remove DNA lesions from the transcribed strand of active genes, permitting rapid resumption of blocked transcription. This repair mechanism has been well characterized in the past using individual target genes. Moreover, numerous efforts investigated the fate of blocked RNA polymerase II (Pol II) during DNA repair mechanisms and suggested that stopped Pol II complexes can either backtrack, be removed and degraded or bypass the lesions to allow TCR. We investigated the effect of a non-lethal dose of UVB on global DNA-bound Pol II distribution in human cells. We found that the used UVB dose did not induce Pol II degradation however surprisingly at about 93% of the promoters of all expressed genes Pol II occupancy was seriously reduced 2-4 hours following UVB irradiation. The presence of Pol II at these cleared promoters was restored 5-6 hours after irradiation, indicating that the negative regulation is very dynamic. We also identified a small set of genes (including several p53 regulated genes), where the UVB-induced Pol II clearing did not operate. Interestingly, at promoters, where Pol II promoter clearance occurs, TFIIH, but not TBP, follows the behavior of Pol II, suggesting that at these genes upon UVB treatment TFIIH is sequestered for DNA repair by the TCR machinery. In agreement, in cells where the TCR factor, the Cockayne Syndrome B protein, was depleted UVB did not induce Pol II and TFIIH clearance at promoters. Thus, our study reveals a UVB induced negative regulatory mechanism that targets Pol II transcription initiation on the large majority of transcribed gene promoters, and a small subset of genes, where Pol II escapes this negative regulation

The protein level of Pol II and GTF subunits does not change after UVB treatment.

<p>(A) Western blot assays were carried out to measure the levels of total Pol II at the indicated time points after UVB treatment by using the N-20 antibody. (B) The different IIA and IIO forms of Pol II were densitometrically quantified in each time points from four independent experiments and are represented in a bar chart, where red bars indicate Pol IIA and the blue bars indicate Pol IIO forms. In each lane Pol IIA+IIO signals are taken as 100%. Error bars represent +/− standard deviation of the four independent experiments. (C) The phosphorylation levels of Pol II Rpb1-CTD Ser2, Ser5 and Ser7 were analyzed by western blot by using the indicated antibodies, respectively. (D) The levels of the indicted GTF subunits such as TFIIB, TBP and TFIIH/CDK7 were also tested in the above prepared extracts, as indicated. Tubulin-α was used as a loading control.</p