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Die Wirkung der Variablen ‚Intelligenz‘ und ‚Geräuschintensität‘ auf die unmittelbare Lernleistung wurde mit zwei Tests untersucht. Dadurch sollten die „Stimulus trace"-Theorie (Ellis 1963) und die „neural theory" (Spitz 1963) bei 45 deutschen, lernbehinderten Kindern geprüft werden. Der „Stimulus trace"-Faktor ließ sich für Geräuschreize nicht bestätigen. Es gab keinen Beweis für die Gültigkeit der neuralen Theorie. Bei Erhöhung der Lautstärke sank die Lernleistung in beiden Tests.
The haemolymph of the adult Colorado potato beetle, Lepinotarsa decemlineata Say, contains a high molecular weight (MW > 200,000) JH-III specific binding protein. The Kd value of the protein for racemic JH-III is 1.3 ± 0.2 × 10−7 M. It has a lower affinity for racemic JH-I and it does not bind JH-III-diol or JH-III-acid. The binding protein does discriminate between the enantiomers of synthetic, racemic JH-III as was determined by stereochemical anaysis of the bound and the free JH-III. Incubation of racemic JH-III with crude haemolymph results in preferential formation of (10S)-JH-III-acid, the unnatural configuration. The JH-esterase present in L. decemlineata haemolymph is not enantioselective. It is concluded that the most important function of the binding protein is that of a specific carrier, protecting the natural hormone against degradation by esterases. The carrier does not protect JH-I as efficiently as the lower homologue.
Langmuir-Blodgett multilayers of hydrocarbon and fluorocarbon polymers with hydrophilic spacer, lipid-polyelectrolyte complexes and mesogenic polymers have been prepared. The thermal behaviour of the multilayers was studied by small angle X-ray scattering, IR and UV—visible spectroscopy. Good thermal stabilities were found for the various classes of polymers. In addition, for both complexed multilayers and mesogenic polymer films, reorientation processes were observed.
The synthesis of galactose clusters that are linked to a steroid moiety by a peptide-like spacer unit is described. The galactose cluster is obtained by Koenigs-Knorr glycosylation of TRIS-Gly-Fmoc (2b) under Helferich conditions. Peptide and ester bonds are formed after activation of carboxylic acids as diphenylthiophene dioxide (TDO) esters. 6a is synthesized in a convergent way by coupling of (Ac4Gal)3-TRIS-Gly (3e) with cholesteryl TDO succinate (5b). Coupling of (Ac4Gal)3-TRIS-Gly hydrogen succinate (3f) with Gly-O-Chol (5d) by means of EEDQ yields 6d. Reaction of (Ac4Gal)3-TRIS-Gly-SUCC-O-TDO (3g) with 25-hydroxycholesterol leads in a linear sequence to the oxysterol derivative 6f. Selective cleavage of the acetyl groups from galactose units yields the known compound 6b and the new derivatives 6e and 6g.
Prostaglandin E₂ has been reported both to stimulate glycogen-phosphorylase activity (glycogenolytic effect) and to inhibit the glucagon-stimulated glycogen-phosphorylase activity (antiglycogenolytic effect) in rat hepatocytes. It was the purpose of this study to resolve this apparent contradiction and to characterize the signalling pathways and receptor subtypes involved in the opposing prostaglandin E₂ actions. Prostaglandin E₂ (10 μM) increased glucose output, glycogen-phosphorylase activity and inositol trisphosphate formation in hepatocyte cell culture andor suspension. In the same systems, prostaglandin E₂ decreased the glucagon-stimulated (1 nM) glycogen-phosphorylase activity and cAMP formation. The signalling pathway leading to the glycogenolytic effect of PGE₂ was interrupted by incubation of the hepatocytes with 4P-phorbol 12-myristate 13-acetate (100 nM) for 10 min, while the antiglycogenolytic effect of prostaglandin E₂ was not attenuated. The signalling pathway leading to the antiglycogenolytic effect of prostaglandin E₂ was interrupted by an incubation of cultured hepatocytes with pertussis toxin (100 ng/ml) for 18 h, whereas the glycogenolytic effect of prostaglandin E₂ was enhanced. The EP₁/EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Sulproston had a stronger glycogenolytic potency than the EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Misoprostol. The antiglycogenolytic potency of both agonists was equal. It is concluded that the glycogenolytic and the antiglycogenolytic effects of prostaglandin E₂ are mediated via different signalling pathways in hepatocytes possibly involving EP₁ and EP₃ prostaglandin E₂ receptors, respectively.
A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of the reflection process are reviewed, and a full wave-mechanical approach based on the analytical soution of the corresponding Schrödinger equation is presented. The phase shift at reflection is calculated exactly and interpreted in terms of instantaneous reflection of the atom at an effective mirror. Besides the semiclassical regime of reflection describable by the WKB method, a pure quantum regime of reflection is identified in the limit where the incident de Broglie wavelength is large compared to the evanescent wave decay length.
Contents: 1 Introduction 2 Formation and destruction of sporadic E-layers 3 Temporal variations of parameters of sporadic E-layers during earthquake preparation 3.1 Temporal variations of fbEs with time-scales of a few hours 3.2 Study of fbEs variations with characteristic time-scales of 0.5-3 hours 3.3 Variations of the parameters of sporadic E-layers with characteristic time-scales of 15-45 minutes 3.4 Sporadic E-layer variations with characteristic time-scales of 2-15 minutes 4 On the spatial scales of sporadic E-layer disturbances related to seismic activity 5 Complex experimental researches of the ionosphere, electromagnetic noise and the geomagnetic field 5.1 Ionospheric and electromagnetic phenomena of the Kayraccum earthquake in 1985 5.2 Comparison of anomalies with characteristic time-scales of 2-3 hours for ionospheric E- and F-layers, and temporal behaviour of electromagnetic noise emission intensity 5.3 Night airglow emissions in the E-region before earthquakes and sporadic E-layer variations 6 Physical models of lithosphere-ionosphere links 6.1 Lithosphere-ionosphere links due to AGW 6.2 Electromagnetic models for the lithosphere-ionosphere coupling 6.3 Sporadic E-layers as current generators 7 Discussion and conclusion
Das Menderes Massiv im Westen der Türkei stellt eine große Kulmination metamorpher Gesteine dar. Das Untersuchungsgebiet ist im Zentralen Menderes Massiv (Ödemis Submassiv) gelegen, das von den beiden aktiven Gräben, dem Gediz Graben im Norden und dem Büyük Menderes Graben im Süden begrenzt wird. Die Untersuchungen der Eklogit Relikte im zentralen Menderes Massiv haben ergeben, dass sich im Menderes Massiv Hochdruckrelikte in unterschiedlichen tektonischen Positionen befinden. Zum einen existieren Eklogit-Blöcke in der obersten Einheit (Selcuk Einheit) des zentralen Menderes Massivs und zum anderen Hochdruck-Relikte in der strukturell mittleren Birgi - Tire Decke. Die Granate der quarzfreien Eklogit-Blöcke weisen große Ähnlichkeiten mit denen der HP/LT Gesteine von Sifnos und Syros auf. Die Entwicklung der Eklogit-Blöcke in der Olistostrom-Einheit lässt sich jedoch nicht mit den Eklogit Relikten in der strukturell mittleren Birgi Tire Decke vergleichen. Für die Eklogit-Relikte in der Birgi Tire Decke wurde eine polymetamorphe Entwicklung mithilfe petrologischer Untersuchungen und chemischen und Pb-Pb Datierungen herausgearbeitet. Die Eklogit Relikte gehören zu einem metamorphen Teilpfad, der durch eine Amphibolitfazies 1 - Hochdruck - Amphibolitfazies 2/Granulitfazies charakterisiert ist. Der Endpunkt dieses Teilpfades ist mit Temperaturen zwischen 700 und 750 °C und Drücken von 1.2 - 1.4 GPa belegt. Für diese Bedingungen konnte ein minimales Alter von 520 Ma durch chemische Datierungen an Monaziten einer Augengneisprobe und Pb-Pb Datierungen an Zirkonen einer Augengneis- und Metagabbroprobe bestimmt werden. Dieser amphibolit/granulitfazieller Endpunkt wird mit den Granitintrusionen des zentralen und südlichen Menderes Massiv korreliert, die in einem Zeitraum zwischen 520 Ma bis 550 Ma stattfanden. Sowohl die Amphibolitfazies 1 als auch das Hochdruckereignis werden der Panafrikanischen Orogenese zugeordnet. Für die Hochdruckbedingungen wurden maximale Temperaturen zwischen 680°C und 720°C und bei einem Druck von 2.2 GPa bestimmt. In den untersuchten Metasedimenten konnte eine prograde metamorphe Entwicklung abgeleitet werden, die amphibolitfazielle Bedingungen von 660°C bei 0.6 GPa erreichte. Das Metamorphosealter dieser Metasedimente konnte mit < 100 Ma mittels chemischer Mikrosondendatierung bestimmt werden. Die in den Metasedimenten herausgearbeiteten Druck- und Temperaturbedingungen wurden ebenfalls in den metabasischen Gesteinen bestimmt. Diese Ergebnisse werden als Krustenstapelung der metabasischen Gesteine, Augengneise und Metasedimente interpretiert, die mit der alpinen Orogenese im Zusammenhang stehen. Durch die Ergebnisse dieser Arbeit lässt sich die Birgi-Tire Decke im zentralen Menderes Massiv genauer charakterisieren. Sie besteht aus Metasedimenten, pelitischen Gneisen, Augengneisen und metabasichen Gesteinen. Die Gneise (pelitische und Augengneise) und die metabasischen Gesteine stellen panafrikanische Relikte dar, die einen amphibolit- eklogit- amphibolit/granulitfaziellen Metamorphosepfad gespeichert haben. Die amphibolit- bis granulitfazielle Metamorphose hängt mit den Granitintrusionen zusammen und fand in einem Zeitraum zwischen 520 - 550 Ma statt. Große Teile der Metasedimente der Birgi Tire Decke haben jedoch nur eine alpine metamorphe Entwicklung durchlaufen, wo sie unter amphibolitfazielle Bedingungen Krustentiefen erreichten, bei denen sie mit den panafrikanischen Relikten zusammen gestapelt wurden und eine gemeinsame Exhumierung erfahren haben.
Das Ziel dieser Arbeit ist es, die Strukturen im äußeren Erdkern zu untersuchen und Rückschlüsse auf die sich daraus ergebenden Konsequenzen für geodynamische Modellvorstellungen zu ziehen. Die Untersuchung der Kernphasenkaustik B mit Hilfe einer kumulierten Amplituden-Entfernungskurve ist Gegenstand des ersten Teils. Dazu werden die absoluten Amplituden der PKP-Phasen im Entfernungsbereich von 142 ° bis 147 ° bestimmt und mit den Amplituden synthetischer Seismogramme verglichen. Als Datenmaterial dienen die Breitbandregistrierungen des Deutschen Seismologischen Re-gionalnetzes (GRSN 1 ) und des Arrays Gräfenberg (GRF). Die verwendeten Wellen-formen werden im WWSSN-SP-Frequenzbereich gefiltert. Als Datenbasis dienen vier Tiefherdbeben der Subduktionszone der Neuen Hebriden (Vanuatu Island) und vier Nuklearexplosionen, die auf dem Mururoa und Fangataufa Atoll im Südpazifik stattgefunden haben. Beide Regionen befinden sich vom Regionalnetz aus gesehen in einer Epizentraldistanz von ungefähr 145 °. Die Verwendung eines homogen instrumentierten Netzes von Detektoren und die Anwendung von Stations- und Magnitudenkorrekturen verringern den Hauptteil der Streuung bei den Amplitudenwerten. Dies gilt auch im Vergleich zu Untersuchungen von langperiodischen Amplituden im Bereich der Kernphasenkaustik (Häge, 1981). Ein weiterer Grund für die geringe Streuung ist die ausschließliche Verwendung von Ereignissen mit kurzer impulsiver Herdzeitfunktion. Erst die geringe Streuung der Amplitudenwerte ermöglicht eine Interpretation der Daten. Die theoretischen Amplitudenkurven der untersuchten Erdmodelle zeigen im Bereich der Kaustik B einen gleichartigen Kurvenverlauf. Bei allen Berechnungen wird ein einheitliches Modell für die Güte der P- und S-Wellen verwendet, das sich aus den Q-Werten der Modelle CIT112 und PREM 2 zusammensetzt. Die mit diesem Q-Modell berechneten Amplituden liegen in geringem Maße oberhalb der gemessenen Amplituden. Dies braucht nicht berücksichtigt zu werden, da die kumulierte Amplituden-Entfernungskurve anhand der Lage des Maximums auf der Entfernungsachse ausgewertet wird. Folglich wird darauf verzichtet, ein alternatives Q-Modell zu entwickeln. Hinsichtlich der Lage des Kaustikmaximums lassen sich die untersuchten Erdmodelle in zwei Kategorien einteilen. Eine Gruppe besteht aus den Modellen IASP91 und 1066B, deren Maxima bei 144.6 ° und 144.7 ° liegen. Zur zweiten Gruppe von Modellen zählen AK135, PREM und SP6 mit den Maxima bei 145.1 ° und 145.2 ° (SP6). Die gemessene Amplitudenkurve hat ihr Maximum bei 145 °. Alle Entfernungsangaben beziehen sich auf eine Herdtiefe von 200 km. Die Kaustikentfernung für einen Oberflächenherd ist jeweils um 0.454 ° größer als die angegeben Werte. Damit liegen die Maxima der Modelle AK135 und PREM nur 0.1 ° neben dem der gemessenen kumulierten Amplitudenkurve. Daher wird auf die Erstellung eines eigenen Modells verzichtet, da dieses eine unwesentlich verbesserte Amplitudenkurve aufweisen würde. Das Ergebnis der Untersuchung ist die Erstellung einer gemessenen kumulierten Amplituden-Entfernungskurve für die Kaustik B. Die Kurve legt die Position der Kaustik B für kurzperiodische Daten auf ± 0.15 ° fest und bestimmt damit, welche Erdmodelle für die Beschreibung der Amplituden im Entfernungsbereich der Kaustik B besonders geeignet sind. Die Erdmodelle AK135 und PREM, ergänzt durch ein einheitliches Q-Modell, geben den Verlauf der Amplituden am besten wieder. Da die Amplitudenkurven beider Modelle nahe beieinander liegen, sind sie als gleichwertig zu bezeichnen. Im zweiten Teil der Arbeit wird die Struktur der Übergangszone in den inneren Erdkern anhand des spektralen Abklingens der Phase PKP(BC)diff am Punkt C der Laufzeitkurve untersucht. Der physikalische Prozeß der Beugung ist für die starke Abnahme der Amplituden dieser Phase verantwortlich. Die Diffraktion beeinflußt das Abklingverhalten verschiedener Frequenzanteile des seismischen Signals auf unterschiedliche Weise. Eine Deutung des Verhaltens erfordert die Berechnung von Abklingspektren. Dabei wird die Abschwächung des PKP(BC)diff Signals für acht Frequenzen zwischen 6.4 s und 1.25 Hz ermittelt und als Spektrum dargestellt. Die Form des Abklingspektrums ist charakteristisch für die Beschaffenheit der Geschwindigkeitsstruktur direkt oberhalb der Grenze zum inneren Erdkern (GIK). Die Beben, deren Kernphasen im Regionalnetz als diffraktierte Kernphasen BCdiff registriert werden, liegen in einem Entfernungsbereich jenseits von 150 °. In dieser Distanz befinden sich die Erdbebenherde der Tonga-Fidschi-Subduktionszone, deren Breitbandaufzeichnungen verwendet werden. Die Auswertung unkorrigierter Wellenformen ergibt Abklingspektren, die mit plausiblen Erdmodellen nicht in Einklang zu bringen sind. Aus diesem Grund werden die Daten einer spektralen Stationskorrektur unterzogen, die eigens zu diesem Zweck ermittelt wird. Am Beginn der Auswertung steht eine Prüfung bekannter Erdmodelle mit unterschiedlichen Geschwindigkeitsstrukturen oberhalb der GIK. Zu den untersuchten Modellen zählen PREM, IASP91, AK135Q, PREM2, SP6, OICM2 und eine Variante des PREM. Die Untersuchung ergibt, daß Modelle, die einen verringerten Gradienten oberhalb der GIK aufweisen, eine bessere Übereinstimmung mit den gemessenen Daten zeigen als Modelle ohne diese Übergangszone. Zur Verifikation dieser These wird ein Erdmodell, das keinen verringerten Gradienten oberhalb der GIK besitzt (PREM), durch eine Reihe unterschiedlicher Geschwindigkeitsverläufe in diesem Bereich ergänzt und deren synthetische Seismogramme berechnet. Das Resultat der Untersuchung sind zwei Varianten des PREM, deren Frequenzanalyse eine gute Übereinstimmung mit den Daten zeigt. Das Abklingspektrum des Erdmodells PD47, das in einer 380 km mächtigen Schicht einen negativen Gradienten besitzt, zeigt eine große Ähnlichkeit mit den gemessenen Spektren. Dennoch kann es nicht als realistisches Modell angesehen werden, da der Punkt C in einer zu großen Entfernung liegt. Darüber hinaus müßte die zu kurze Differenzlaufzeit zwischen PKP(AB) und PKP(DF) beziehungsweise PKIKP durch eine größere Änderung der Geschwindigkeitsstruktur im inneren Kern kompensiert werden. Es wird deshalb das Modell PD27a favorisiert, das diese Nachteile nicht aufweist. PD27a besitzt eine Schicht konstanter Geschwindigkeit oberhalb der GIK mit einer Mächtigkeit von 150 km. Die Art des Geschwindigkeitsverlaufs steht im Einklang mit der geodynamischen Modellvorstellung, nach der eine Anreicherung leichter Elemente oberhalb der GIK vorliegt, die als Ursache für die Konvektion im äußeren Erdkern anzusehen ist.
In the present study, photophysical properties of [N]phenylenes were studied by means of stationary and time-resolved absorption and fluorescence spectroscopy (in THF at room temperature). For biphenylene (1) and linear [3]phenylene (2a), internal conversion (IC) with quantum yields ΦIC > 0.99 is by far the dominant mechanism of S1 state deactivation. Angular [3]phenylene (3a), the zig-zag [4]- and [5]phenylenes (3b), (3c), and the triangular [4]phenylene (4) show fluorescence emission with fluorescence quantum yieds and lifetimes between ΦF = 0.07 for (3a) and 0.21 for (3c) and τF = 20 ns for (3a) and 81 ns for (4). Also, compounds (3) and (4) exhibit triplet formation upon photoexcitation with quantum yields as high as ΦISC = 0.45 for (3c). The strong differences in the fluorescence properties and in the triplet fromation efficiencies between (1) and (2a) on one hand and (3) and (4) on the other are related to the remarkable variation of the internal conversion (IC) rate constants kIC. A tentative classification of (1) and (2a) as “fast IC compounds”, with kIC > 109 s-1, and of (3) and (4) as “slow IC compounds”, with kIC ≈ 107 s-1, is suggested. This classification cannot simply be related to Hückel’s rule-type concepts of aromaticity, because the group of “fast IC compounds” consists of “antiaromatic” (1) and “aromatic” (2a), and the group of “slow IC compounds” consists of “antiaromatic” (3b), (4) and “aromatic” (3a), (3c). The IC in the [N]phenylenes is discussed within the framework of the so-called energy gap law established for non-radiative processes in benzenoid hydrocarbons.
An approach to the development of fluorescent probes to follow polymerizations in situ using fluorinated cross-conjugated enediynes (Y-enynes) is reported. Different substitution patterns in the Y-enynes result in distinct solvatochromic behavior. β,β-Bis(phenylethynyl)pentafluorostyrene 7, which bears no donor substituents and only fluorine at the styrene moiety, shows no solvatochromism. Donor substituted β,β-bis(3,4,5-trimethoxyphenylethynyl) pentafluorostyrene 8 and β,β-bis(4-butyl-2,3,5,6-tetrafluorophenylethynyl)-3,4,5-trimethoxystyrene 9 exhibit solvatochromism upon change of solvent polarity. Y-enyne 8 showed the largest solvatochromic shift (94 nm bathochromic shift) upon changing solvent from cyclohexane to acetonitrile. A smaller solvatochromic response (44 nm bathochromic shift) was observed for 9. Lippert–Mataga treatment of 8 and 9 yields slopes of -10,800 and -6,400 cm -1, respectively. This corresponds to a change in dipole moment of 9.6 and 6.9 D, respectively. The solvatochromic behavior in 8 and 9 supports the formation of an intramolecular charge transfer (ICT) state. The low fluorescence quantum yields are caused by competitive double bond rotation. The fluorescence decay time of 9 decreases in methyltetrahydrofuran from 2.1 ns at 77 K to 0.11 ns at 200 K. Efficient single bond rotation in 9 was frozen at -50 °C in a configuration in which the trimethoxyphenyl ring is perpendicular to the fluorinated rings. 7–9 are photostable compounds. The X-ray structure of 7 shows it is not planar and that its conjugation is distorted. Y-enyne 7 stacks in the solid state showing coulombic, actetylene–arene, and fluorine–π interactions.
This paper argues that the texts surviving from the Old English period do not reflect the spoken language of the bulk of the population under Anglo-Saxon elite domination. While the Old English written documents suggest that the language was kept remarkably unchanged, i.e. was strongly monitored during the long OE period (some 500 years!), the spoken and "real Old English" is likely to have been very different and much more of the type of Middle English than the written texts. "Real Old Engish", i.e. of course only appeared in writing after the Norman Conquest. Middle English is therefore claimed to have begun with the 'late British' speaking shifters to Old English. The shift patterns must have differed in the various part of the island of Britain, as the shifters became exposed to further language contact with the Old Norse adstrate in the Danelaw areas and the Norman superstrate particularly in the South East, the South West having been least exposed to language contact after the original shift from 'Late British' to Old English. This explains why the North was historically the most innovative zone. This also explains the conservatism of the present day dialects in the South West. It is high time that historical linguists acknowledge the arcane character of the Old English written texts.
Vibrationally resolved fluorescence spectra of four angular [N]phenylenes were recorded with laser excited Shpol’skii spectroscopy (LESS) in an n-octane matrix at 10 K. In general, the same vibrational frequencies were observed in the fluorescence excitation and emission spectra, indicating that the geometries of ground and electronically excited state are very similar. Because of intensity borrowing from the S2 state, vibrations of two different symmetries were observed in the fluorescence excitation spectra of angular [3]phenylene and zig-zag[5]phenylene. This finding allowed the location of the S2 state for these compounds. DFT calculations(RB3LYP/6-31G*) of the ground state vibrational frequencies were made. The calculated vibrational modes were in reasonably good agreement with the experimental data. A new very low-frequency vibration of approximately 100 cm-1 was predicted and experimentally confirmed for all [N]phenylenes investigated. This vibration seems to be unique for [N]phenylenes and is attributed to an in-plane movement of the carbon backbone.
Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [4]phenylene (D3h[4]phenylene) were studied using laser-excited Shpolskii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm–1 and 1176 cm–1, suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4]phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4]phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm–1 probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state.
Daniel Lerner’s „The Passing of Traditional Society“ of 1958 is still one of the most famous American studies in the field of modernization research. This article gives a deeper insight into the background of the emergence of the study. The author describes Lerner’s theoretical and empirical work and its connection to the policy of his time. A classic today in modernization theory, Lerner’s study was initially merely a request for the Voice of America to investigate the use of media in the Middle Eastern region –modernization or development did not yet play a significant role. The article shows how the direction of the study changed from its original intention into a political opinion research and thus into a political propaganda tool.
Forum: EU-Diplomatie im Jahre 2020
We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a wavelength range from FUV to optical, and remain consistent with Hα data. We have achieved an excellent match of the P V λλ1118, 1128 resonance doublet and N IV λ1718, as well as He II λ4686 suggesting that our physical description of clumping is adequate. We find very small volume filling factors and that clumping starts deep in the wind, near the sonic point. The most crucial consequence of our analysis is that the mass loss rates of O stars need to be revised downward significantly, by a factor of 3 and more compared to those obtained from smooth-wind models.
First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants kq and the free energy change of the electron transfer (ΔG0CS ) could be described by the Rehm-Weller equation. From the experimental results, a reorganization energy λ of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic ΔG0CS can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state.
INTEGRAL tripled the number of super-giant high-mass X-ray binaries (sgHMXB) known in the Galaxy by revealing absorbed and fast transient (SFXT) systems. Quantitative constraints on the wind clumping of massive stars can be obtained from the study of the hard X-ray variability of SFXT. A large fraction of the hard X-ray emission is emitted in the form of flares with a typical duration of 3 ksec, frequency of 7 days and luminosity of $10^{36}$ erg/s. Such flares are most probably emitted by the interaction of a compact object orbiting at $\sim10~R_*$ with wind clumps ($10^{22 ... 23}$ g) representing a large fraction of the stellar mass-loss rate. The density ratio between the clumps and the inter-clump medium is $10^{2 ... 4}$. The parameters of the clumps and of the inter-clump medium, derived from the SFXT flaring behavior, are in good agreement with macro-clumping scenario and line-driven instability simulations. SFXT are likely to have larger orbital radius than classical sgHMXB.
We present one-dimensional, time-dependent models of the clumps generated by the linedeshadowing instability. In order to follow the clumps out to distances of more than 1000 R∗, we use an efficient moving-box technique. We show that, within the approximations, the wind can remain clumped well into the formation region of the radio continuum.
We report FUSE observations in 2005–2006 of three O-type, double-lined spectroscopic binaries in the Magellanic Clouds. The systems have very short periods (1.4–2.25 d), represent rare, young evolutionary stages of massive stars and binaries, and provide a unique glimpse at some of the most massive systems that form in dense clusters of massive stars. Improved orbit parameters, including revised masses, for LH54-425 are derived from new ctio spectroscopy. The systems are: LH54-425 in the LMC (O3V + O5V, P=2.25d, 62+37M⊙), J053441-693139 in the LMC (O2-3If+O6V, P=1.4 d, 41+27M⊙), and Hodge 53-47 in the SMC (O6V + O4-5IIIf, P=2.2 d, 24+14M⊙, where the O4 star appears to be less massive than the O6 star). Their short periods indicates that wind interaction and mass transfer are likely important factors in their evolution. The spectra provide quantitative and systematic studies of phase-dependent stellar wind properties, wind collision effects in O+O binaries at lower metallicities, improved radial velocity curves, and FUV spectro-photometric changes as a function of orbital phase.
Extract: [...]Of all the print-media newspapers are the most commonly used. They are not literature in the sense of belles letters, but they should not be underestimated in their political, social and personal importance. No other printed product is as closely linked with everyday life as the newspapers. The day begins under their influence, and their contents mirror the events of the day with varying accuracy. Newspapers are strongly reader-oriented. They want to inform, but they also want to instil opinions. Specific choices of information shape the content level. Specific choices of language are resorted to in order to spread opinions and viewpoints. Language creates solidarity between the producers and the consumers of newspapers and thereby supports ideologies by specifically targeted linguistic means. Other strategies are employed for the same purpose, too. Visual aspects are of great importance, such as the typographical layout, the use of pictures, drawings, colours, fonts, etc.[...]
Background: Hybrids represent a cornerstone in the success story of breeding programs. The fundamental principle underlying this success is the phenomenon of hybrid vigour, or heterosis. It describes an advantage of the offspring as compared to the two parental lines with respect to parameters such as growth and resistance against abiotic or biotic stress. Dominance, overdominance or epistasis based models are commonly used explanations. Conclusion/Significance: The heterosis level is clearly a function of the combination of the parents used for offspring production. This results in a major challenge for plant breeders, as usually several thousand combinations of parents have to be tested for identifying the best combinations. Thus, any approach to reliably predict heterosis levels based on properties of the parental lines would be highly beneficial for plant breeding. Methodology/Principal Findings: Recently, genetic data have been used to predict heterosis. Here we show that a combination of parental genetic and metabolic markers, identified via feature selection and minimum-description-length based regression methods, significantly improves the prediction of biomass heterosis in resulting offspring. These findings will help furthering our understanding of the molecular basis of heterosis, revealing, for instance, the presence of nonlinear genotype-phenotype relationships. In addition, we describe a possible approach for accelerated selection in plant breeding.
Der gemeinsame Wandel der inselkeltischen Sprachen wie auch des Englischen vom vorwiegend synthetischen Typus zum vorwiegend analytischen Typus läßt sich vermutlich auf einen ca. 1500 Jahre dauernden intensiven Sprachenkontakt zwischen diesen Sprachen zurückführen. Heute ist das Englische die analytischste Sprache der Britischen Inseln und Irlands, gefolgt vom Walisischen, Bretonischen und Irischen. Letzteres ist von den genannten Sprachen noch am weitesten morphologisch komplex.
Prediction of hybrid biomass in Arabidopsis thaliana by selected parental SNP and metabolic markers
(2009)
A recombinant inbred line (RIL) population, derived from two Arabidopsis thaliana accessions, and the corresponding testcrosses with these two original accessions were used for the development and validation of machine learning models to predict the biomass of hybrids. Genetic and metabolic information of the RILs served as predictors. Feature selection reduced the number of variables (genetic and metabolic markers) in the models by more than 80% without impairing the predictive power. Thus, potential biomarkers have been revealed. Metabolites were shown to bear information on inherited macroscopic phenotypes. This proof of concept could be interesting for breeders. The example population exhibits substantial mid-parent biomass heterosis. The results of feature selection could therefore be used to shed light on the origin of heterosis. In this respect, mainly dominance effects were detected.
Im Februar 2009 endet die Lehr- und Forschungstätigkeit von Günter C. Behrmann an der Universität Potsdam. Anlässlich seiner Emeritierung gibt das Zentrum für Lehrerbildung der Universität ausgewählte Aufsätze, die Günter C. Behrmann während seiner Potsdamer Zeit publiziert hat, heraus. Diese Aufsätze spiegeln seine Lehr- und Forschungsinteressen sowie sein Engagement in der universitären Selbstverwaltung, sie zeigen die Verbindung zwischen der Deutung einer historischen Lage und den Folgerungen, die Behrmann für die Lösung praktischer politisch-pädagogischer Probleme aus dieser Deutung erschloss. Lebenslauf und Schriftenverzeichnis ergänzen die Festschrift und öffnen den Blick für das Wirken und das wissenschaftliche Werk Günter C. Behrmanns in seiner Gesamtheit.
From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles.
From the seedpods of Tephrosia elata, a new β-hydroxydihydrochalcone named (S)-elatadihydrochalcone was isolated. In addition, the known flavonoids obovatachalcone, obovatin, obovatin methyl ether and deguelin were identified. The structures were determined on the basis of spectroscopic evidence. The crude extract and the flavonoids obtained from the seedpods of this plant showed antiplasmodial activities. The literature NMR data on β-hydroxydihydrochalcones is reviewed and the identity of some of the compounds assigned β-hydroxydihydrochalcone skeleton is questioned.
Portal alumni
(2010)
Das gerade begonnene Jahr wird für die Universität Potsdam ein besonderes werden, ist es doch das 20. Jahr ihres Bestehens. Auf das Erreichte ist die Hochschule mit Recht stolz. Die Universität Potsdam ist für Studieninteressierte ungebrochen attraktiv, was die steigenden Bewerberzahlen zeigen. Allein im vergangenen Jahr haben Uni-Wissenschaftler knapp 42 Millionen Euro Drittmittel eingeworben und die Liste gemeinsamer Verbundprojekte mit außeruniversitären Forschungseinrichtungen der Region wächst weiter. Zu den Erfolgen zählt weiterhin auch die steigende Anzahl von Absolventinnen und Absolventen der Hochschule.
In die Gründung der Universität Potsdam am 15. Juli 1991 flossen zwei Vorgängereinrichtungen ein. Die wichtigste war die Brandenburgische Landeshochschule, vorher Pädagogische Hochschule, die über vier Jahrzehnte hinweg Lehrerinnen und Lehrer ausgebildet hat. Die Lehrerbildung hat auch für die Universität Potsdam profilbildenden Charakter, denn allein vier der fünf Fakultäten sind an der Lehrerbildung beteiligt und haben Generationen von jungen Leuten für den Lehrerberuf qualifiziert. Heute ist das Ziel aller an der Lehrerbildung Beteiligten, eine professionsorientierte, qualitativ hochwertige Lehrerbildung zu sichern, die sich an den Kompetenzen Erziehen, Unterrichten, Beraten, Betreuen, Innovieren und Organisieren orientiert. Eine besondere Herausforderung sieht die Universität Potsdam dabei in der Vernetzung von wissenschaftlicher Forschung und Lehrerbildung.
Portal alumni stellt in der hier vorliegenden Ausgabe im Jubiläumsjahr zwölf Absolventen der Lehrerbildung vor. Sie berichten aus jeweils individueller Perspektive, wie sie ihr Studium an der Universität Potsdam erlebt haben und wie es sie geprägt hat. Und natürlich stellt das Magazin zugleich aktuelle Entwicklungstrends in der Lehrerbildung vor. Wie in allen Heften zuvor berichten wir von der Alumni-Arbeit des Jahres 2010 und stellen Höhepunkte des Unialltags vor. Wir wünschen Ihnen eine unterhaltsame Lektüre und sind gespannt auf Ihr Feedback zu diesem Heft.
Abzug, um zu bleiben
(2011)
Für den Einsatz in Autobatterien gibt es besondere Anforderungen an den Elektrolyten im Bereich der Energie- und Leistungsdichten, um beispielsweise thermische Verluste gering zu halten. Hochleitfähige Elektrolyte mit Leitfähigkeiten im Millisiemensbereich sind hier ebenso notwendig wie auch sichere, d.h. möglichst nicht brennbare und einen niedrigen Dampfdruck besitzende Materialien. Um diese Vorgaben zu erreichen, ist es notwendig, einen polymeren Separator zu entwickeln, welcher auf brennbare organische Lösungsmittel verzichtet und damit eine drastische Steigerung der Sicherheit gewährleistet. Gleichzeitig müssen hierbei die Leistungsvorgaben bezüglich der Leitfähigkeit erfüllt werden. Zu diesem Zweck wurde ein Konzept basierend auf der Kombination von einer polymeren sauerstoffreichen Matrix und einer ionischen Flüssigkeit entwickelt und verifiziert. Dabei wurden folgende Erkenntnisse gewonnen: 1. Es wurden neuartige diacrylierte sauerstoffreiche Matrixkomponenten mit vielen Carbonylfunktionen, für eine gute Lithiumleitfähigkeit, synthetisiert. 2. Es wurden mehrere neue ionische Flüssigkeiten sowohl auf Imidazolbasis als auch auf Ammoniumbasis synthetisiert und charakterisiert. 3. Die Einflüsse der Kationenstruktur und der Einfluss der Gegenionen im Bezug auf Schmelzpunkte und Leitfähigkeiten wurden untersucht. 4. Aus den entwickelten Materialien wurden Blendsysteme hergestellt und mittels Impedanzspektrometrie untersucht: Leitfähigkeiten von 10-4S/cm bei Raumtemperatur sind realisierbar. 5. Die Blendsysteme wurden auf ihre thermische Stabilität hin untersucht: Stabilitäten bis 250°C sind erreichbar. Dabei wird keine kristalline Struktur beobachtet.
Background: Development of eukaryotic organisms is controlled by transcription factors that trigger specific and global changes in gene expression programs. In plants, MADS-domain transcription factors act as master regulators of developmental switches and organ specification. However, the mechanisms by which these factors dynamically regulate the expression of their target genes at different developmental stages are still poorly understood.
Results: We characterized the relationship of chromatin accessibility, gene expression, and DNA binding of two MADS-domain proteins at different stages of Arabidopsis flower development. Dynamic changes in APETALA1 and SEPALLATA3 DNA binding correlated with changes in gene expression, and many of the target genes could be associated with the developmental stage in which they are transcriptionally controlled. We also observe dynamic changes in chromatin accessibility during flower development. Remarkably, DNA binding of APETALA1 and SEPALLATA3 is largely independent of the accessibility status of their binding regions and it can precede increases in DNA accessibility. These results suggest that APETALA1 and SEPALLATA3 may modulate chromatin accessibility, thereby facilitating access of other transcriptional regulators to their target genes.
Conclusions: Our findings indicate that different homeotic factors regulate partly overlapping, yet also distinctive sets of target genes in a partly stage-specific fashion. By combining the information from DNA-binding and gene expression data, we are able to propose models of stage-specific regulatory interactions, thereby addressing dynamics of regulatory networks throughout flower development. Furthermore, MADS-domain TFs may regulate gene expression by alternative strategies, one of which is modulation of chromatin accessibility.
The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects.
The Strange-tailed Tyrant Alectrurus risora (Aves: Tyrannidae) is an endemic species of southern South American grasslands that suffered a 90% reduction of its original distribution due to habitat transformation. This has led the species to be classified as globally Vulnerable. By the beginning of the last century, populations were partially migratory and moved south during the breeding season. Currently, the main breeding population inhabits the Ibera wetlands in the province of Corrientes, north-east Argentina, where it is resident all year round. There are two remaining small populations in the province of Formosa, north-east Argentina, and in southern Paraguay, which are separated from the main population by the Parana-Paraguay River and its continuous riverine forest habitat. The populations of Corrientes and Formosa are separated by 300 km and the grasslands between populations are non-continuous due to habitat transformation. We used mtDNA sequences and eight microsatellite loci to test if there were evidences of genetic isolation between Argentinean populations. We found no evidence of genetic structure between populations (Phi(ST) = 0.004, P = 0.32; Fst = 0.01, P = 0.06), which can be explained by either retained ancestral polymorphism or by dispersal between populations. We found no evidence for a recent demographic bottleneck in nuclear loci. Our results indicate that these populations could be managed as a single conservation unit on a regional scale. Conservation actions should be focused on preserving the remaining network of areas with natural grasslands to guarantee reproduction, dispersal and prevent further decline of populations.
In this work we present a CMOS high frequency direct immunosensor operating at 6 GHz (C-band) for label free determination of creatinine. The sensor is fabricated in standard 0.13 μm SiGe:C BiCMOS process. The report also demonstrates the ability to immobilize creatinine molecules on a Si3N4 passivation layer of the standard BiCMOS/CMOS process, therefore, evading any further need of cumbersome post processing of the fabricated sensor chip. The sensor is based on capacitive detection of the amount of non-creatinine bound antibodies binding to an immobilized creatinine layer on the passivated sensor. The chip bound antibody amount in turn corresponds indirectly to the creatinine concentration used in the incubation phase. The determination of creatinine in the concentration range of 0.88–880 μM is successfully demonstrated in this work. A sensitivity of 35 MHz/10 fold increase in creatinine concentration (during incubation) at the centre frequency of 6 GHz is gained by the immunosensor. The results are compared with a standard optical measurement technique and the dynamic range and sensitivity is of the order of the established optical indication technique. The C-band immunosensor chip comprising an area of 0.3 mm2 reduces the sensing area considerably, therefore, requiring a sample volume as low as 2 μl. The small analyte sample volume and label free approach also reduce the experimental costs in addition to the low fabrication costs offered by the batch fabrication technique of CMOS/BiCMOS process.
Flower development is controlled by the action of key regulatory transcription factors of the MADS-domain family. The function of these factors appears to be highly conserved among species based on mutant phenotypes. However, the conservation of their downstream processes is much less well understood, mostly because the evolutionary turnover and variation of their DNA-binding sites (BSs) among plant species have not yet been experimentally determined. Here, we performed comparative ChIP (chromatin immunoprecipitation)-seq experiments of the MADS-domain transcription factor SEPALLATA3 (SEP3) in two closely related Arabidopsis species: Arabidopsis thaliana and A. lyrata which have very similar floral organ morphology. We found that BS conservation is associated with DNA sequence conservation, the presence of the CArG-box BS motif and on the relative position of the BS to its potential target gene. Differences in genome size and structure can explain that SEP3 BSs in A. lyrata can be located more distantly to their potential target genes than their counterparts in A. thaliana. In A. lyrata, we identified transposition as a mechanism to generate novel SEP3 binding locations in the genome. Comparative gene expression analysis shows that the loss/gain of BSs is associated with a change in gene expression. In summary, this study investigates the evolutionary dynamics of DNA BSs of a floral key-regulatory transcription factor and explores factors affecting this phenomenon.
GEOMAGIA50.v3
(2015)
Background: GEOMAGIA50.v3 for sediments is a comprehensive online database providing access to published paleomagnetic, rock magnetic, and chronological data obtained from lake and marine sediments deposited over the past 50 ka. Its objective is to catalogue data that will improve our understanding of changes in the geomagnetic field, physical environments, and climate.
Findings: GEOMAGIA50.v3 for sediments builds upon the structure of the pre-existing GEOMAGIA50 database for magnetic data from archeological and volcanic materials. A strong emphasis has been placed on the storage of geochronological data, and it is the first magnetic archive that includes comprehensive radiocarbon age data from sediments. The database will be updated as new sediment data become available.
Conclusions: The web-based interface for the sediment database is located at http://geomagia.gfz-potsdam.de/geomagiav3/SDquery.php. This paper is a companion to Brown et al. (Earth Planets Space doi:10.1186/s40623-015-0232-0,2015) and describes the data types, structure, and functionality of the sediment database.
Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100
(2015)
Arctic animals face dramatic habitat alteration due to ongoing climate change. Understanding how such species have responded to past glacial cycles can help us forecast their response to today's changing climate. Gray whales are among those marine species likely to be strongly affected by Arctic climate change, but a thorough analysis of past climate impacts on this species has been complicated by lack of information about an extinct population in the Atlantic. While little is known about the history of Atlantic gray whales or their relationship to the extant Pacific population, the extirpation of the Atlantic population during historical times has been attributed to whaling. We used a combination of ancient and modern DNA, radiocarbon dating and predictive habitat modelling to better understand the distribution of gray whales during the Pleistocene and Holocene. Our results reveal that dispersal between the Pacific and Atlantic was climate dependent and occurred both during the Pleistocene prior to the last glacial period and the early Holocene immediately following the opening of the Bering Strait. Genetic diversity in the Atlantic declined over an extended interval that predates the period of intensive commercial whaling, indicating this decline may have been precipitated by Holocene climate or other ecological causes. These first genetic data for Atlantic gray whales, particularly when combined with predictive habitat models for the year 2100, suggest that two recent sightings of gray whales in the Atlantic may represent the beginning of the expansion of this species' habitat beyond its currently realized range.
Brief communication
(2015)
Accelerating climate change and increased economic and environmental interests in permafrost-affected regions have resulted in an acute need for more directed permafrost research. In June 2014, 88 early career researchers convened to identify future priorities for permafrost research. This multidisciplinary forum concluded that five research topics deserve greatest attention: permafrost landscape dynamics, permafrost thermal modeling, integration of traditional knowledge, spatial distribution of ground ice, and engineering issues. These topics underline the need for integrated research across a spectrum of permafrost-related domains and constitute a contribution to the Third International Conference on Arctic Research Planning (ICARP III).
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland
(2015)
Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (< 1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.
The evolution of massive stars in very low metallicity galaxies is less well observationally
constrained than in environments more similar to the Milky Way, M33, or the LMC. We discuss
in this contribution the current state of our program to search for and characterize Wolf-Rayet stars (and other massive emission line stars) in low metallicity galaxies in the Local Volume.
PopIII-star siblings in IZw18 and metal-poor WR galaxies unveiled from integral field spectroscopy
(2015)
Here, we highlight our recent results from the IFS study of Mrk178, the closest metal-poor WR galaxy, and of IZw18, the most metal-poor star-forming galaxy known in the local Universe. The IFS data of Mrk178 show the importance of aperture effects on the search for WR features, and the extent to which physical variations in the ISM properties can be detected. Our IFS data of IZw18 reveal its entire nebular HeIIλ4686-emitting region, and indicate for the very first time that peculiar, hot (nearly) metal-free ionizing stars (called here PopIII-star siblings) might hold the key to the HeII-ionization in IZw18.
The main objective of this work is to investigate the evolution of massive stars, and the interplay between them and the ionized gas for a sample of local metal-poor Wolf-Rayet galaxies.
Optical integral field spectrocopy was used in combination with multi-wavelength radio data.
Combining optical and radio data, we locate Wolf-Rayet stars and supernova remnants across the Wolf-Rayet galaxies to study the spatial correlation between them. This study will shed light on the massive star formation and its feedback, and will help us to better understand
distant star-forming galaxies.
Before GAIA improves the HIPPARCOS survey, direct determination of the distance via parallax is only possible for γ Vel, but the analysis of the cluster or association to which WR stars are associated can give distances with a 50% to a 10% accuracy. The list of Galactic clusters, associations and clusters/association candidates has grown significantly in the last decade with the numerous deep, high resolution surveys of the Milky Way. In this work, we revisit the fundamental parameters of known clusters with WR stars, and we present the search for new ones. All our work is based on the catalogs from the VVV (from the VISTA telescope) and the UKIDS (from the UKIRT telescope) near infrared surveys. Finally, the relations between the fundamental parameters of clusters with WR stars are explored.