154 research outputs found

    Temperature dependent segregation behaviour of stepped surfaces

    Get PDF
    II+132hlm.;24c

    KI-basierte Detektion von GebÀuden mittels Deep Learning und amtlichen Geodaten zur Baufallerkundung

    Get PDF
    Zusammenfassung: Es wird ein neuartiger Ansatz vorgestellt, der auf einer Erkennung von GebĂ€uden und GebĂ€udeverĂ€nderungen aus hochaufgelösten Luftbildern anhand von KĂŒnstlicher Intelligenz (KI) beruht. Die zum Trainieren des KI-Systems notwendigen DatenbestĂ€nde sind die GebĂ€udeumrisse aus der amtlichen Digitalen Flurkarte (DFK) und das lagerichtige Digitale Orthophoto (TrueDOP). Die semantische Detektion der GebĂ€ude und GebĂ€udeverĂ€nderungen erfolgt ĂŒber optische Aufnahmen und OberflĂ€chenmodelle, wie dem normalisierten OberflĂ€chenmodell (nDOM) und einem aus der Differenz von zwei Zeitepochen abgeleiteten OberflĂ€chenmodell (tDOM). Am Beispiel der Baufallerkundung werden die Ergebnisse einer aktuellen Forschungskooperation zwischen der Bayerischen Vermessungsverwaltung (BVV) und der Technischen UniversitĂ€t MĂŒnchen (TUM) aufgezeigt und bestehenden Verfahrenslösungen gegenĂŒbergestellt. Die vorgestellte KI-basierte Verfahrenslösung ist grundsĂ€tzlich auf alle Vermessungsverwaltungen der LĂ€nder bundesweit ĂŒbertragbar. Summary: A novel approach is introduced which is based on the detection of buildings and building changes from high-resolution aerial images using artificial intelligence (AI). The data sets necessary for training the AI system are the building outlines from the official Digital Cadastre Map (DFK) and Digital Orthophotos without building lean (TrueDOP). The semantic detection of the buildings and building changes is carried out based on optical images and digital surface models, such as the normalized digital surface model (nDOM) and a Temporal Digital Surface Model (tDOM) derived from the difference of two time epochs. The results of the current cooperation between the Bavarian Agency for Digitisation, High-Speed Internet and Surveying (BVV) and the Technical University of Munich (TUM) on the detection of buildings and building changes are presented and compared with results derived from existing approaches. The presented AI-based solution is basically transferable to all surveying administrations of the federal states nationwide

    Selective sweeps on novel and introgressed variation shape mimicry loci in a butterfly adaptive radiation.

    Get PDF
    Natural selection leaves distinct signatures in the genome that can reveal the targets and history of adaptive evolution. By analysing high-coverage genome sequence data from 4 major colour pattern loci sampled from nearly 600 individuals in 53 populations, we show pervasive selection on wing patterns in the Heliconius adaptive radiation. The strongest signatures correspond to loci with the greatest phenotypic effects, consistent with visual selection by predators, and are found in colour patterns with geographically restricted distributions. These recent sweeps are similar between co-mimics and indicate colour pattern turn-over events despite strong stabilising selection. Using simulations, we compare sweep signatures expected under classic hard sweeps with those resulting from adaptive introgression, an important aspect of mimicry evolution in Heliconius butterflies. Simulated recipient populations show a distinct 'volcano' pattern with peaks of increased genetic diversity around the selected target, characteristic of sweeps of introgressed variation and consistent with diversity patterns found in some populations. Our genomic data reveal a surprisingly dynamic history of colour pattern selection and co-evolution in this adaptive radiation

    Ancient and historical DNA in conservation policy

    Get PDF
    Although genetic diversity has been recognized as a key component of biodiversity since the first Convention on Biological Diversity (CBD) in 1993, it has rarely been included in conservation policies and regulations. Even less appreciated is the role that ancient and historical DNA (aDNA and hDNA, respectively) could play in unlocking the temporal dimension of genetic diversity, allowing key conservation issues to be resolved, including setting baselines for intraspecies genetic diversity, estimating changes in effective population size (N-e), and identifying the genealogical continuity of populations. Here, we discuss how genetic information from ancient and historical specimens can play a central role in preserving biodiversity and highlight specific conservation policies that could incorporate such data to help countries meet their CBD obligations.Peer reviewe

    Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide

    Full text link
    [EN] Three fluorescent probes (1–3) for the selective and sensitive detection of hydrogen sulfide have been synthesized and characterized. Probe 1 is a coumarin derivative functionalized with an azide moiety whereas 2 contain the azide reactive group into a naphthalene fluorophore backbone. Probe 3 is composed also by a naphthalene fluorophore but, in this case, functionalized with a sulfonylazide reactive moiety. Probes 1 and 3 are non-fluorescent whereas 2 is weakly emissive in HEPES (10 mM, pH 7.4)–DMSO 99:1 (v/v). The emission behavior of the three probes was tested against selected anions, bio-thiols and oxidant molecules. Of all the chemical species tested, only HS− is able to induce an enhancement in the emission intensity (50, 11 and 20-fold for 1, 2 and 3, respectively). The observed emission in the presence of hydrogen sulfide is ascribed, in the case of probes 1 and 2, to an azide–amine reduction induced by HS− anion, whereas for probe 3 the sensing mechanism is related with a sulfonylazide–sulfonamide conversion. The three probes are very sensitive to HS− anion with limits of detection of 0.17, 0.20 and 0.40 mM for 1, 2 and 3 respectively. Cell viability studies demonstrated that 1–3 probes are essentially non-toxic at concentrations 10–50 ÎŒM and are well suited for in vivo studies. Finally, probe 1 was used for the detection on intracellular HS− anion in HeLa cells by means of confocal microscopy.Financial support from the Spanish Government (Project MAT2012-38429-004-01) and the Generalitat Valenciana (Project PROMETEO/2009/016) is gratefully acknowledged. S.E. is grateful to the Generalitat Valenciana for his Santiago Grisolia fellow. C.T. also thanks the Ministerio de Ciencia e Innovacion for her FPU grant. L.E.S.F. thanks the Carolina Foundation and UPNFM-Honduras for his doctoral grant.El Sayed Shehata Nasr, S.; De La Torre Paredes, C.; Santos Figueroa, LE.; MarĂ­n HernĂĄndez, C.; MartĂ­nez Mañez, R.; SancenĂłn Galarza, F.; Costero Nieto, AM.... (2015). Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide. Sensors and Actuators B: Chemical. 207(B):987-994. https://doi.org/10.1016/j.snb.2014.04.047S987994207

    Subsurface hydrothermal processes and the bioenergetics of chemolithoautotrophy at the shallow-sea vents off Panarea Island (Italy)

    Get PDF
    The subsurface evolution of shallow-sea hydrothermal fluids is a function of many factors including fluid-mineral equilibria, phase separation, magmatic inputs, and mineral precipitation, all of which influence discharging fluid chemistry and consequently associated seafloor microbial communities. Shallow-sea vent systems, however, are understudied in this regard. In order to investigate subsurface processes in a shallow-sea hydrothermal vent, and determine how these physical and chemical parameters influence the metabolic potential of the microbial communities, three shallow-sea hydrothermal vents associated with Panarea Island (Italy) were characterized. Vent fluids, pore fluids and gases at the three sites were sampled and analyzed for major and minor elements, redox-sensitive compounds, free gas compositions, and strontium isotopes. The corresponding data were used to 1) describe the subsurface geochemical evolution of the fluids and 2) to evaluate the catabolic potential of 61 inorganic redox reactions for in situ microbial communities. Generally, the vent fluids can be hot (up to 135 °C), acidic (pH 1.9-5.7), and sulfidic (up to 2.5 mM H2S). Three distinct types of hydrothermal fluids were identified, each with higher temperatures and lower pH, Mg2 + and SO42 -, relative to seawater. Type 1 was consistently more saline than Type 2, and both were more saline than seawater. Type 3 fluids were similar to or slightly depleted in most major ions relative to seawater. End-member calculations of conservative elements indicate that Type 1 and Type 2 fluids are derived from two different sources, most likely 1) a deeper, higher salinity reservoir and 2) a shallower, lower salinity reservoir, respectively, in a layered hydrothermal system. The deeper reservoir records some of the highest end-member Cl concentrations to date, and developed as a result of recirculation of brine fluids with long term loss of steam and volatiles due to past phase separation. No strong evidence for ongoing phase separation is observed. Type 3 fluids are suggested to be mostly influenced by degassing of volatiles and subsequently dissolution of CO2, H2S, and other gases into the aqueous phase. Gibbs energies (ΔGr) of redox reactions that couple potential terminal electron acceptors (O2, NO3-, MnIV, FeIII, SO42 -, S0, CO2,) with potential electron donors (H2, NH4+, Fe2 +, Mn2 +, H2S, CH4) were evaluated at in situ temperatures and compositions for each site and by fluid type. When Gibbs energies of reaction are normalized per kilogram of hydrothermal fluid, sulfur oxidation reactions are the most exergonic, while the oxidation of Fe2 +, NH4+, CH4, and Mn2 + are moderately energy yielding. The energetics calculations indicate that the most robust microbial communities in the Panarea hot springs combine H2S from deep water-rock-gas interactions with O2 that is entrained via seawater mixing to fuel their activities, regardless of site location or fluid type

    MicroRNA-96 Directly Inhibits Îł-Globin Expression in Human Erythropoiesis

    Get PDF
    Fetal hemoglobin, HbF (α2Îł2), is the main hemoglobin synthesized up to birth, but it subsequently declines and adult hemoglobin, HbA (α2ÎČ2), becomes predominant. Several studies have indicated that expression of the HbF subunit Îł-globin might be regulated post-transcriptionally. This could be confered by ∌22-nucleotide long microRNAs that associate with argonaute proteins to specifically target Îł-globin mRNAs and inhibit protein expression. Indeed, applying immunopurifications, we found that Îł-globin mRNA was associated with argonaute 2 isolated from reticulocytes that contain low levels of HbF (<1%), whereas association was significantly lower in reticulocytes with high levels of HbF (90%). Comparing microRNA expression in reticulocytes from cord blood and adult blood, we identified several miRNAs that were preferentially expressed in adults, among them miRNA-96. The overexpression of microRNA-96 in human ex vivo erythropoiesis decreased Îł-globin expression by 50%, whereas the knock-down of endogenous microRNA-96 increased Îł-globin expression by 20%. Moreover, luciferase reporter assays showed that microRNA-96 negatively regulates expression of Îł-globin in HEK293 cells, which depends on a seedless but highly complementary target site located within the coding sequence of Îł-globin. Based on these results we conclude that microRNA-96 directly suppresses Îł-globin expression and thus contributes to HbF regulation
    • 

    corecore