Ultraviolet properties of individual hot stars in globular cluster cores. 1: NGC 1904 (M 79)

As part of an observing program using the International Ultraviolet Explorer (IUE) satellite to investigate the ultraviolet properties of stars found within the cores of galactic globular clusters with blue horizontal branches (HBs), we obtained three spectra of the cluster NGC 1904 (M 79). All three were long integration-time, short-wavelength (SWP) spectra obtained at the so called 'center of light' and all three showed evidence of sources within the IUE large aperture (21.4 in. by 10 in.). In this paper we shall describe the analysis of these spectra and present evidence that the UV sources represent individual hot stars in the post-HB stage of evolution

A small cichlid species flock from the Upper Miocene (9--10 MYA) of Central Kenya

Fossil cichlids from East Africa offer unique insights into the evolutionary history and ancient diversity of the family on the African continent. Here we present three fossil species of the extinct haplotilapiine cichlid †Baringochromis gen. nov. from the upper Miocene of the palaeolake Waril in Central Kenya, based on the analysis of a total of 78 articulated skeletons. †Baringochromis senutae sp. nov., †B. sonyii sp. nov. and †B. tallamae sp. nov. are superficially similar, but differ from each other in oral-tooth dentition and morphometric characters related to the head, dorsal fin base and body depth. These findings indicate that they represent an ancient small species flock. Possible modern analogues of palaeolake Waril and its species flock are discussed. The three species of †Baringochromis may have begun to subdivide their initial habitat by trophic differentiation. Possible sources of food could have been plant remains and insects, as their fossilized remains are known from the same place where †Baringochromis was found

Benchmarking Of Risk Management Methods With Regard to Variations As A Source Of Risk

When developing new systems, there is always some kind of reference to existing systems. Various approaches aim at describing qualitatively different characteristics of such connections, often depicted as some form of variation. Among other things, this is done with regard to innovation potential and development risk. In this paper, we investigate the extent to which established methods of risk management refer to modelling approaches for variations by means as mentionend above. After a litertaure search 11 methods and method clusters are analyzed more in detail within a method benchmark

New haplochromine cichlid from the upper Miocene (9-10 MYA) of Central Kenya

Background: The diversification process known as the Lake Tanganyika Radiation has given rise to the most speciose clade of African cichlids. Almost all cichlid species found in the lakes Tanganyika, Malawi and Victoria, comprising a total of 12-16 tribes, belong to this clade. Strikingly, all the species in the latter two lakes are members of the tribe Haplochromini, whose origin remains unclear. The 'out of Tanganyika' hypothesis argues that the Haplochromini emerged simultaneously with other cichlid tribes and lineages in Lake Tanganyika, presumably about 5-6 million years ago (MYA), and that their presence in the lakes Malawi and Victoria and elsewhere in Africa today is due to later migrations. In contrast, the 'melting pot Tanganyika hypothesis' postulates that Haplochromini emerged in Africa prior to the formation of Lake Tanganyika, and that their divergence could have begun about 17 MYA. Haplochromine fossils could potentially resolve this debate, but such fossils are extremely rare. Results: Here we present a new fossil haplochromine from the upper Miocene site Waril (9-10 million years) in Central Kenya. Comparative morphology, supported by Micro-CT imaging, reveals that it bears a unique combination of characters relating to dentition, cranial bones, caudal skeleton and meristic traits. Its most prominent feature is the presence of exclusively unicuspid teeth, with canines in the outer tooth row. †Warilochromis unicuspidatus gen. et sp. nov. shares this combination of characters solely with members of the Haplochromini and its lacrimal morphology indicates a possible relation to the riverine genus Pseudocrenilabrus. Due to its fang-like dentition and non-fusiform body, †W. unicuspidatus gen. et sp. nov. might have employed either a sit-and-pursue or sit-and-wait hunting strategy, which has not been reported for any other fossil haplochromine cichlid. Conclusions: The age of the fossil (9-10 MYA) is incompatible with the 'out of Tanganyika' hypothesis, which postulates that the divergence of the Haplochromini began only 5-6 MYA. The presence of this fossil in an upper Miocene palaeolake in the Central Kenya Rift, as well as its predatory lifestyle, indicate that Haplochromini were already an important component of freshwater drainages in East Africa at that time

Spatially resolved spectroscopy of AG Carinae, and direct evidence for stellar evolution: The central star of NGC 2392

We have performed spatially-resolved low dispersion long-slit spectroscopy for the circumstellar shell of the luminous blue variable AG Carinae with IUE between lambda lambda 1200 - 3200 A. At all positions a strong dust-scattered stellar continuum is detected. Only a few emission lines, FE II 2600 and O I (?) 1304, have been detected; the emission is stronger on the southern side of the shell. The UV surface brightness and derived dust properties are completely consistent with the groundbased and KAO FIR observations: the grains are large (0.1 - 1 micron), warm (45 - 100 K depending on composition), highly reflecting (C(sub sca)/C(sub abs) approximately equal to 1), and tie up about 10(exp -4) to 10(exp -3) solar mass of material. We also observe similarities of the results for HR Car and LBV's to those reported here

A New Framework for Network Disruption

Traditional network disruption approaches focus on disconnecting or lengthening paths in the network. We present a new framework for network disruption that attempts to reroute flow through critical vertices via vertex deletion, under the assumption that this will render those vertices vulnerable to future attacks. We define the load on a critical vertex to be the number of paths in the network that must flow through the vertex. We present graph-theoretic and computational techniques to maximize this load, firstly by removing either a single vertex from the network, secondly by removing a subset of vertices.Comment: Submitted for peer review on September 13, 201

Untersuchung zum Einfluss von schwerer Karies und Molaren-Inzisiven-Hypomineralisation im Hinblick auf die mundgesundheitsbezogene Lebensqualität von Kindern

Kinder, die von Molaren-Inzisiven-Hypomineralisation (MIH) betroffen sind, leiden häufig an stark hypersensiblen Zähnen. Dies erschwert die Nahrungsaufnahme durch Schmerzen beim Essen und Trinken und verschlechtert die häusliche Mundhygiene, was ein erhöhtes Kariesrisiko zur Folge hat. Darüber hinaus beeinträchtigen gelblichbräunliche Opazitäten an den Fazialflächen der Inzisiven das Erscheinungsbild der Kinder. Mädchen und Jungen mit kariösen Zähnen zeigen ab einem bestimmten Schweregrad ganz ähnliche Symptome wie Kinder mit MIH. Auch hier vermindern schmerzende Molaren und optisch veränderte kariöse Frontzähne die Lebensqualität der Betroffenen erheblich. Das Ziel der Studie war es, den Effekt von therapeutischen Maßnahmen bei Kindern mit schwerer Karies und schwerer MIH auf die mundgesundheitsbezogene Lebensqualität (MLQ) durch einen Vorher-Nachher-Vergleich zu analysieren. Ferner sollte untersucht werden, bei welchem der beiden Krankheitsbilder eine stärkere Verbesserung der Lebensqualität erzielt werden kann. Zu diesem Zweck wurden 210 Kinder der Kinderzahnarztpraxis ‚Leo Löwenzahn‘ aus Bergisch Gladbach untersucht und in zwei Gruppen unterteilt. Die erste Gruppe bestand aus Probanden mit mindestens zwei schweren kariösen Läsionen, die Kinder der zweiten Gruppe hatten mindestens zwei stark hypomineralisierte Zähne. Um die Einschlusskriterien zu erfüllen, durften die Kinder nur eine der beiden Erkrankungen aufweisen. In dieser Studie wurde das von Michaelis et al. (2021) entwickelte Risikoschema verwendet, was sowohl Probanden mit MIH als auch mit Karies in drei Schweregradkategorien differenziert. Im Rahmen einer klinischen Untersuchung wurde zunächst die Schwere der einzelnen erkrankten Zähne bewertet. Bei den MIH-Probanden geschah dies mit Hilfe der MIH-Klassifikation von Mathu-Muju & Wright (2006). Das Ausmaß der kariösen Zerstörung wurde unter Zuhilfenahme eines Diagno-Pens nach der ADAKariesklassifikation (American Dental Association) bewertet. Unter Berücksichtigung des klinischen Schweregrades der Erkrankung der Zähne wurden bei beiden Krankheitsbildern Risikopunkte verteilt, die zu einem Summenwert addiert einen entsprechenden Risiko-Score ergaben. Die Summe der Risikowerte der Probanden ordnet die Patienten in die entsprechende 'Schweregradkategorie' ein, so dass der Schweregrad beider Erkrankungen vergleichbar ist. Für diese Studie wurden nur Kinder im Alter von 7 und 11 Jahren aus der High-Severity-Category eingeschlossen. Um die subjektive Beeinträchtigung der MLQ der Probanden zu erheben wurde die deutsche Version des Child-Perceptions-Questionnaire-8-10 (CPQ-G8–10) verwendet. Die Datenanalyse wurde mit der Software SPSS 22 (IBM Corp., USA) durchgeführt und umfasste die deskriptive Analyse und Wilcoxon-Rangsummen-Test. P-Werte wurden als signifikant angesehen, wenn sie kleiner als 0,05 waren. Das Durchschnittsalter der Studienteilnehmer lag bei 9 (±2) Jahren und war in beiden Gruppen gleich, da sie nach Alter gematched wurden. Nach Winkler und Stolzenberg (2009) gehörte mehr als die Hälfte (54%) der Studienpopulation zur Mittelschicht. Die meisten Patienten (84%) wurden im Wachzustand behandelt, die übrigen unter Sedierung oder Narkose. In der MIH-Gruppe waren die Seitenzähne häufiger betroffen als die Frontzähne, wobei die Hälfte der bleibenden Seitenzähne (57%) und fast alle (97%) Frontzähne eine invasive Therapie benötigten. Der Gesamt-CPQ in der MIH-Gruppe war mit einem Ausgangswert von 17,8 am höchsten, während der Wert bei den Probanden der Kariesgruppe 13,8 betrug. Dies zeigt, dass bei vergleichbarem Schweregrad, Patienten mit stark ausgeprägter MIH stärker in ihrer Lebensqualität beeinträchtigt wurden als Kinder mit entsprechenden kariösen Läsionen. Innerhalb der Subdomänen zeigte sich die stärkste Beeinträchtigung bei beiden Erkrankungen im Bereich 'orale Symptome'. Ein signifikanter Unterschied (p>0,01) vor der Behandlung bestand in der Domäne 'funktionelle Einschränkungen', da die MIH-Gruppe einen deutlich höheren Wert (4,9 ± 3,3) als die Kariesgruppe (2,9 ± 3,6) aufwies. Das bestätigt, dass Kinder mit MIH-Zähnen funktionell mehr eingeschränkt waren. Nach der Therapie erreichten beide Gruppen einen ähnlichen CPQ-Gesamtwert (7,5 ±4,7 bzw. 7,3 ± 6,7). Dies zeigt, dass bei einer adäquaten zahnärztlichen Sanierung bei beiden Erkrankungen, trotz unterschiedlicher Bereiche der Einschränkung, eine ähnliche Verbesserung in der MLQ erreicht werden konnte. Die Ergebnisse dieser Dissertation bestätigen die Hypothese, dass eine befundorientierte und adäquate Therapie die Lebensqualität der betroffenen Kinder bei beiden Krankheitsbildern anzuheben vermag. Der Ausgangswert beim CPQ-G8–10 war zwar bei Probanden mit schwerer MIH signifikant höher als bei Patienten mit schwerer Karies, dennoch konnte die MLQ nach geeigneter Therapie in beiden Gruppen auf das gleiche Niveau angehoben werden. Vor dem Hintergrund der massiven Auswirkungen beider Krankheitsbilder auf die Gesundheit und das Wohlbefinden der Betroffenen hat das klinische Management eine zentrale Bedeutung.:Inhaltsverzeichnis 1. Einführung ............................................................................................... 1 1.1 Allgemeine Angaben zum Krankheitsbild von Karies und Molaren-Inzisiven- Hypomineralisation (MIH) ..................................................................... 1 1.1.2 Ätiologie, klinisches Erscheinungsbild und Klassifizierung von Karies........ 2 1.1.3 Ätiologie, klinisches Erscheinungsbild und Klassifizierung der MIH ........... 4 1.2 Einfluss von Karies und MIH auf die MLQ von Kindern ............................... 6 1.2.1 Messinstrumente für MLQ ..................................................................... 6 1.2.2 Einfluss der Karies auf die MLQ von Kindern .......................................... 8 1.2.3 Einfluss der MIH auf die MLQ von Kindern ........................................... 10 1.3 Therapiemethoden von Karies und MIH .................................................. 11 1.3.1 Therapie von Karies ........................................................................... 11 1.3.2 Therapie von MIH .............................................................................. 12 1.4 Ziel der Studie ...................................................................................... 14 2. Publikationsmanuskript ........................................................................... 16 3. Zusammenfassung .................................................................................. 28 4. Literaturverzeichnis ................................................................................. 31 5. Anlagen ................................................................................................. 4

Fish fossils from Miocene palaeolakes in the East African Rift Valley in Kenya

Africa’s modern-day freshwater fish fauna comprises more than 3000 species, many of them endemic, and is dominated by a few teleost lineages among which the Cyprinodontiformes and the Cichlidae are especially prominent. Even though members of both groups are used as model organisms in evolutionary studies, their evolutionary history is not yet fully understood. This is in part due to their scant fossil record. The main purpose of this dissertation is to investigate the palaeodiversity of freshwater fishes on the African continent during the Miocene epoch, focusing particularly on the Lukeino and Ngorora Formations in the Central Kenya Rift. The material described in this study forms part of a collection consisting of about 650 articulated fish fossils, which were recovered from the upper Miocene Lukeino Formation and the middle–upper Miocene Ngorora Formation in the course of two field campaigns in 2013 and 2014. To provide a context for a better understanding of the new fossils of Cyprinodontiformes and Cichlidae, a comprehensive comparative dataset, including data on meristics, osteology, scale characters and otolith morphology, was assembled for extant representatives of both groups. The dataset for the Cichlidae includes all previously recognized lineages of African cichlids, and is the first of its kind designed to facilitate the phylogenetic placement of cichlid fossils. This new dataset was used to organize the taxonomic studies and to analyse the phylogenetic relationships of the fossils. The results presented here shed new light on the evolutionary history of both Cyprinodontiformes and Cichlidae, and provide new information on Miocene palaeoenvironments and hydrological networks in the Central Kenya Rift. The upper Miocene Lukeino Formation has yielded numerous well-preserved cyprinodontiform fossils of an extinct lineage of the suborder Aplocheiloidei, which represent the first fossil record of this group. On the basis of the morphological study and the phylogenetic analysis, the new taxon was assigned to the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The specimens of †K. kipkechi show wide variation in their meristic counts and morphometric traits, which is comparable to that found in recent sympatric species with variable grades of hybridization. †K. kipkechi thus presumably represents a fossil species flock in statu nascendi. The phylogenetic analysis unexpectedly places †K. kipkechi in a sister relationship to the exclusively Neotropical family Rivulidae, a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. Moreover, the comparison with the recent material revealed that previously proposed apomorphic characters concerning the neural and haemal spines of the preural vertebrae in the caudal skeleton should be revised. The scarcity of other typical freshwater fishes in the Lukeino Formation and the close relationship of †K. kipkechi to the aplocheiloid families Nothobranchiidae and Rivulidae suggest a seasonally dry climate for the palaeoenvironment. Some recent members of the Nothobranchiidae and Rivulidae are known to withstand such harsh conditions due to their ability to produce desiccation-resistant eggs. The new taxon may perhaps have had a similar life cycle. In addition, deformities of the vertebral column are prominent in our sample and point to a strong influence of volcanic activity on the aquatic environment. The study of the middle–upper Miocene Ngorora fish Lagerstätte uncovered two remarkable new fossil taxa of the family Cichlidae. The first is †Protochromis pickfordi nov. gen. nov. sp. Comparative osteological and meristic studies revealed that †P. pickfordi is closely related to the present-day tribes Ectodini and Limnochromini in Lake Tanganyika. This is further supported by a Principal Coordinates Analysis based on meristic data. Due to its unique character set, which includes a tripartite lateral line and a lacrimal with six lateral line tubules, it is suggested that †P. pickfordi belongs to a precursor lineage of the ‘ancient Tanganyika mouth-brooders’. The presence of a Miocene precursor of Lake Tanganyika cichlids far outside the drainage area of the present-day Lake Tanganyika implies an ancient hydrological connection between the Central Kenya Rift and Lake Tanganyika, which supports the hypothesis that a significant portion of the genomic diversity of modern-day Lake Tanganyika cichlids is derived from riverine cichlids. The second new taxon, †Baringochromis nov. gen., is based on the analysis of 335 well-preserved fossil specimens. Its unique combination of characters, most prominently one predorsal bone, six infraorbitals including a lacrimal with four or five lateral line tubules, a partially scaled suboperculum and a low number of anal and dorsal fin spines, puts it in an intermediate position between the almost pan-African Oreochromini and the exclusively East African Haplochromini. This placement is supported by a Principal Coordinates Analysis based on meristic data. The discovery of †Baringochromis therefore suggests a scenario in which precursor lineages of the present-day Oreochromini and Haplochromini were widely distributed throughout East Africa and underwent hybridization in rivers prior to the formation of the Rift Lakes. Taken together, the data reveal that, due to their mosaic-like character sets, the new fossil cyprinodontiform and cichlid taxa cannot be confidently placed within available phylogenetic trees. This implies that the evolutionary history of these two freshwater fish groups cannot be described solely in terms of lineage splitting, and probably involved introgression and hybridization, as already suggested by studies based on molecular data for the Cichlidae. Moreover, the results highlight the value of fossil archives with high preservation quality, like the Lukeino Formation and the Ngorora fish Lagerstätte, for the understanding of past evolutionary processes

DAS KONZEPT DER NACHHALTIGKEIT ZWISCHEN ANSPRUCH UND WIRKLICHKEIT — UNTER BESONDERER BERÜCKSICHTIGUNG KULTURELLER, TECHNOLOGIEPOLITISCHER UND GESELLSCHAFTLICHER PROBLEME

Iako koncept održivosti nije sasvim precizan, on je racionalan i u sebi sadrži obvezu odnosa prema prirodi. Budući da se prije nije vodilo brigu o ekološkom balansu (ravnoteži), danas ispitujemo posljedice takvog ponašanja za okoliš, sadašnji i budući svijet. Nasuprot antropocentričnom shvaćanju života, autor se zalaže za biocentrični koncept, koji pruža dobre mogućnosti rekonstrukcije života nastavljajući dosadašnji kontinuitet. Samo uz globalno mišljenje i odgovorno djelovanje prilagođavanjem vremenskoj dimenziji povijesti života — prirodnog životnog ritma — moguće je bez straha pred budućnošću ostvariti novo kreativno razdoblje. Uzoritu etičku poziciji nalazi u Schweitzerovom načelu strahopoštovanja pred životom: »Ja sam život koji želi živjeti, unutar života koji želi živjeti«.Although the concept of sustainability is not completely precise, it is rational and comprises in itself the obligation of relation to nature. Since the attention has not been paid to the care for the environmental balance, today we examine the consequences of such environmental behavior for nowadays and future world. In contrast to anthropocentric worldview, the author pledges for the biocentric concept, that offers good prospects of life reconstruction proceeding with the present continuity. Only through global consideration and responsible activity with conforming to the time dimension of life history — natural life rhythm — it is possible to realize, with no fear, a new creative era. A distinguished ethical standpoint the author finds in Schweitzer\u27s principle of reverence towards life: "I am life that wants to live, within life that wants to live".Obwohl das Konzept der Nachhaltigkeit nicht ganz präzise ist, ist es rational und beinhaltet die Pfilicht des Verhältnisses zur Natur. Da dem ökologischen Gleichgewicht früher keine Rechnung getragen wurde, haben wir heute die Folgen solchen Verhaltens für die Umwelt, für die jetzige und die zukünftige Welt zu prüfen. Im Gegensatz zur anthropozentrischen Sicht des Lebens setzt sich der Autor für das biozentrische Konzept ein, das gute Möglichkeiten zur Wiederherstellung des Lebens unter Fortsetzung der bisherigen Kontinuität bietet. Nur durch globale Denkweise und verantwortungsvolles Handeln durch die Anpassung an die zeitliche Geschichtsdimension des Lebens — den natürlichen Lebensrhythmus — kann ein neuer kreativer Zeitraum ohne Angst vor der Zukunft verwirklicht werden. Eine beispielhafte ethische Position liegt in dem Grundsatz von Schweitzer über die Ehrfurcht vor dem Leben vor: "Ich bin das Leben, das leben will, innerhalb des Lebens, das leben will.