A comparison of the moss floras of Chile and New Zealand

Chile and New Zealand share a common stock of 181 species of mosses in 94 genera and 34 families. This number counts for 23.3% of the Chilean and 34.6% of the New Zealand moss flora. If only species with austral distribution are taken into account, the number is reduced to 113 species in common, which is 14.5% of the Chilean and 21.6% of the New Zealand moss flora. This correlation is interpreted in terms of long distance dispersal resp. the common phytogeographical background of both countries as parts of the palaoaustral floristic region and compared with disjunct moss floras of other continents as well as the presently available molecular data

Molecular evolution, phylogenetics and biogeography in southern hemispheric bryophytes with special focus on Chilean taxa

Researchers have long been fascinated by disjunct distribution patterns of plant and animal species. Especially the disjunctly distributed species occurring in the temperate Chilean and New Zealand rainforests of the southern hemisphere are considered interesting due to the common history these locations share. These areas were originally part of the former Gondwana landmass. There are also moss species from temperate forest habitats revealing such a disjunct distribution. The native moss flora of Chile comprises about 780 species. According to a study on the Chilean and New Zealand mosses 113 of these 780 species reveal a disjunct austral distribution pattern and also occur in New Zealand. The majority of the species common to both countries are inhabitants of temperate rainforests. This study investigates phylogenetic relationships within four southern hemispheric bryophyte taxa characteristic for the Chilean and New Zealand temperate rainforests. These taxa consisted of the families Lepyrodontaceae and Ptychomniaceae as well as the genera Acrocladium and Catagonium. The results are discussed within the context of historical and geological processes in order to test the hypothesis whether the distribution patterns can be attributed to a common Gondwanan origin or to long distance dispersal as an alternative explanation. Molecular phylogenetic analyses using molecular markers from nrDNA (ITS region, adk gene) and cpDNA (trnL-trnF region, rps4 gene) were conducted for a large number of specimens representing the taxa under study. Most of these specimens originated from the BryoAustral and the BryoTrop projects. The resulting molecular data set was used to reconstruct phylogenies. Additionally, genetic distances were determined to compliment the phylogenetic results. Firstly, phylogenetic relationships within the Ptychomniaceae and within a taxa group consisting of the Plagiotheciaceae, Lepyrodontaceae and related taxa were investigated. For this purpose phylogenetic analyses based on DNA sequence data were conducted for several data sets. Concerning the family Ptychomniaceae the results showed that the species Ptychomnion ptychocarpon, endemic to the Valdivian rainforest, does not belong to the genus Ptychomnion. In contrast to the other representatives of this genus Ptychomnion ptychocarpon occupies a basal position within the family showing no close relationship to any of the other genera within the family. Further results of this study placed the genus Dichelodontium in the family Ptychomniaceae. This genus was formerly considered a member of the Lepyrodontaceae. Further analyses were performed using specimens of the southern hemispheric genus Lepyrodon. This genus comprises seven species, two of which only occur in New Zealand and Australia and another four which are only found in southern Chile and southern Argentina. In contrast, Lepyrodon tomentosus has a distribution area which covers the southernmost tip of the American continents and expands northwards over Central America up to Mexico. The genetic analyses showed that the two New Zealand-Australian species form a common clade and that the most closely related species originate from Chile. Furthermore, based on the results of both phylogenetic analyses and genetic distances it is concluded that populations of Lepyrodon tomentosus occurring in southern and northern South America, respectively, probably already became separated during the tertiary. Analyses aimed at clarifying the phylogenetic relationships of the genus Acrocladium revealed a close relationship between this genus and the genus Lepyrodon. There has been much discussion on whether the genus Acrocladium comprises a single species or whether a distinction can be made between two species. In this study clear evidence was found for the existence of two genetically distinct species, a Chilean-Argentinian species (A. auriculatum) and a New Zealand-Australian species (A. chlamydophyllum). The genus Catagonium occupies a very basal position within the family Plagiotheciaceae. The study of this genus revealed a high genetic similarity between two species only occurring in northern South America on the one hand and a taxon only found in South Africa on the other hand. Based on this phylogenetic result the conclusion is made that the recent taxa had a common ancestor which occurred on the former Gondwana continent. When this landmass split apart the Catagonium populations found on today's African and South American continents were separated. Not all phylogenetic relationships resulting from analyses of molecular markers found in this study could be explained by vicariance events. Therefore, long distance dispersal is discussed as an explanation for the disjunct distribution of specific taxa

Application of Pulsed Field Gel Electrophoresis to Determine γ-ray-induced Double-strand Breaks in Yeast Chromosomal Molecules

The frequency of DNA double-strand breaks (dsb) was determined in yeast cells exposed to γ-rays under anoxic conditions. Genomic DNA of treated cells was separated by pulsed field gel electrophoresis, and two different approaches for the evaluation of the gels were employed: (1) The DNA mass distribution profile obtained by electrophoresis was compared to computed profiles, and the number of DSB per unit length was then derived in terms of a fitting procedure; (2) hybridization of selected chromosomes was performed, and a comparison of the hybridization signals in treated and untreated samples was then used to derive the frequency of dsb

Computer simulation of pulsed field gel runs allows the quantitation of radiation-induced double-strand breaks in yeast

A procedure for the quantification of double-strand breaks in yeast is presented that utilizes pulsed field gel electrophoresis (PFGE) and a comparison of the observed DNA mass distribution in the gel lanes with calculated distributions. Calculation of profiles is performed as follows. If double-strand breaks are produced by sparsely ionizing radiation, one can assume that they are distributed randomly in the genome, and the resulting DNA mass distribution in molecular length can be predicted by means of a random breakage model. The input data for the computation of molecular length profiles are the breakage frequency per unit length, , as adjustable parameter, and the molecular lengths of the intact chromosomes. The obtained DNA mass distributions in molecular length must then be transformed into distributions of DNA mass in migration distance. This requires a calibration of molecular length vs. migration distance that is specific for the gel lane in question. The computed profiles are then folded with a Lorentz distribution with adjusted spread parameter to account for and broadening. The DNA profiles are calculated for different breakage frequencies and for different values of , and the parameters resulting in the best fit of the calculated to the observed profile are determined

Managing Customer Data in Data-driven Service Innovation: A Framework of Data Principles

While customer data has been collected in enterprise systems since decades, the emerging consumer technologies create new sources of data. Although the need to co-create services with customers has been recognized, a systematic approach of how to include this sensitive source of innovation in the service innovation process is still lacking. This research explores the potential of data governance practices for data-driven service innovation. Data principles for the governance of customer data are collected and assessed by practioners in order to provide conceptual support for organizations and to facilitate the service innovation process. The results of this research integrate data principles of different research streams and offer a framework of data principles that can be applied in the design and management of data-driven services

Automotive radar – investigation of mutual interference mechanisms

In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). <br><br> This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms

Kamerabasiertes System zur kontaktlosen Messung der momentanen Herzfrequenz für den Einsatz unter realen Umgebungsbedingungen

In der vorliegenden Arbeit wird das Messprinzip Photoplethysmography Imaging (PPGI) detailliert analysiert und auf dieser Basis ein System zur kontinuierlichen, kamerabasierten Remote-Messung der Herzfrequenz konzipiert. Der Fokus liegt dabei auf dem Entwurf algorithmischer Ansätze, die eine robuste Erfassung auch in alltäglichen und hinsichtlich Artefakteinflüssen herausfordernden Szenarien ermöglichen. In diesem Zusammenhang werden zunächst das grundlegende Systemkonzept, eine als Entwicklungs- und Evaluationsbasis dienende Datenbank, sowie spezielle, auf die Artefaktkompensation ausgerichtete Algorithmen vorgestellt. Als Beispiel kann der Entwurf eines Multi-Patch-Algorithmus zur adaptiven Wahl geeigneter Subregionen innerhalb der gewählten Messregion Gesicht genannt werden. Zur Untersuchung der zentralen Fragestellung der Einsetzbarkeit und erzielbaren Genauigkeit in Alltagsszenarien wird das entworfene PPGI-System hinsichtlich der Anwendungsfälle „Belastungsmonitoring am Büroarbeitsplatz“ und "Fahrerbeobachtung im Automobil“ evaluiert. Während der Fokus im stationären Büro-Setting auf der Untersuchung der Machbarkeit einer PPGI-basierten Analyse der Herz- bzw. Pulsratenvariabilität (HRV/PRV) liegt, steht im mobilen Setting der Fahrerbeobachtung die Genauigkeit der Herzfrequenzschätzung unter starken Artefakteinflüssen im Vordergrund

ECN with QUIC: Challenges in the Wild

TCP and QUIC can both leverage ECN to avoid congestion loss and its retransmission overhead. However, both protocols require support of their remote endpoints and it took two decades since the initial standardization of ECN for TCP to reach 80% ECN support and more in the wild. In contrast, the QUIC standard mandates ECN support, but there are notable ambiguities that make it unclear if and how ECN can actually be used with QUIC on the Internet. Hence, in this paper, we analyze ECN support with QUIC in the wild: We conduct repeated measurements on more than 180M domains to identify HTTP/3 websites and analyze the underlying QUIC connections w.r.t. ECN support. We only find 20% of QUIC hosts, providing 6% of HTTP/3 websites, to mirror client ECN codepoints. Yet, mirroring ECN is only half of what is required for ECN with QUIC, as QUIC validates mirrored ECN codepoints to detect network impairments: We observe that less than 2% of QUIC hosts, providing less than 0.3% of HTTP/3 websites, pass this validation. We identify possible root causes in content providers not supporting ECN via QUIC and network impairments hindering ECN. We thus also characterize ECN with QUIC distributedly to traverse other paths and discuss our results w.r.t. QUIC and ECN innovations beyond QUIC.Comment: Accepted at the ACM Internet Measurement Conference 2023 (IMC'23

M&A-Transaktionen in der Praxis zwischen Rationalität und Irrationalität: Ergebnisse einer empirischen Dax 30-Studie – Teil 1

M&A-Transaktionen werden selten so erfolgreich, wie sie geplant wurden. Dies wirft immer wieder die Frage auf, ob die Entscheidung für die Transaktion eine „gute“, d. h. rationale Entscheidung war und ob der Prozess auf optimale Weise geführt wurde. Im Rahmen der Studie wurden Experten aus 24 DAX-30-Unternehmen zum Thema „Rationalität und Irrationalität im M&A-Prozess“ befragt. Wunsch und Wirklichkeit fallen demnach deutlich auseinander und gerade Faktoren, die die Rationalität in einem Prozess erhöhen sollen, können diese in eine ungewollte Richtung treiben: Wachstumsstrategie, Anreizsysteme, Gremienentscheidungen, Bewertungsmodelle, auch Eigeninteressen der Akteure und Emotionen spielen eine große Rolle. Die Experten bestätigen insbesondere die hohe Relevanz verhaltenstheoretischer Phänomene wie den Planungsfehlschluss, den Herdeneffekt, oder die Selbstüberschätzung im M&A-Prozess

Entrepreneurship und Start-up-Kultur an der TH Köln. Auswertung der empirischen Erhebung Teil III: Fakultät für Wirtschafts- und Rechtswissenschaften

Die TH Köln hat sich in ihrer Transferstrategie 2025 zur Förderung von Existenzgründungen und Entrepreneurship Education positioniert. Für diese Positionierung ist es bedeutsam, den Status Quo der derzeitigen Start-up-Kultur an der TH Köln zu ermitteln. Die vorliegende Studie geht insbesondere den folgenden Fragen nach: Wie viele Studierende sind bereits selbstständig? Wie viele haben Interesse an dem Thema Existenzgründung? Welche Angebote, die die TH Köln bereits zur Verfügung stellt, sind bekannt und welche zusätzlichen Angebote werden gewünscht? Fühlen sich die Studierenden ausreichend informiert und welche Anregungen haben sie zur Etablierung und Förderung der Start-up-Kultur an der TH Köln