Laboratory rotational ground state transitions of NH3_3D+^+ and CF+^+

Aims. This paper reports accurate laboratory frequencies of the rotational ground state transitions of two astronomically relevant molecular ions, NH3D+ and CF+. Methods. Spectra in the millimeter-wave band were recorded by the method of rotational state-selective attachment of He-atoms to the molecular ions stored and cooled in a cryogenic ion trap held at 4 K. The lowest rotational transition in the A state (ortho state) of NH$_3$D$^+$ ($J_K = 1_0 - 0_0$), and the two hyperfine components of the ground state transition of CF$^+$($J = 1 - 0$) were measured with a relative precision better than $10^{-7}$. Results. For both target ions the experimental transition frequencies agree with recent observations of the same lines in different astronomical environments. In the case of NH$_3$D$^+$ the high-accuracy laboratory measurements lend support to its tentative identification in the interstellar medium. For CF$^+$ the experimentally determined hyperfine splitting confirms previous quantum-chemical calculations and the intrinsic spectroscopic nature of a double-peaked line profile observed in the $J = 1 - 0$ transition towards the Horsehead PDR.Comment: 7 pages, 2 figure

High-Resolution 3D Ptychography

Coherent imaging is a promising method in the field of x-ray microscopy allowing for the nondestructive determination of the interior structure of radiation-hard samples with a spatial resolution that is only limited by the fluence on the sample and the scattering strength of the sample. Ultimately, the achievable spatial resolution is limited by the wavelength of the incoming x-ray radiation. Combining coherent imaging with scanning microscopy to a method called ptychography enables one to also probe extended objects. In this method, a sample is scanned through a defined coherent x-ray beam and at each scan point a diffraction pattern is recorded with a diffraction camera located in the far field of the sample. Neighboring illuminated areas must have a certain overlap to guarantee the collection of sufficient information about the object for a subsequent successful and unique computational reconstruction of the object. Modern ptychographic reconstruction algorithms are even able to reconstruct the complex-valued transmission function of the sample and the complex illumination wave field at the same time. Once the 2D transmission function of a sample is known, it is an obvious step forward to combine ptychography with tomographic techniques yielding the 3D internal structure of an object with unprecedented spatial resolution. Here, projections at varying angular positions of the sample are generated via ptychographic scans and are subsequently used for the tomographic reconstruction. In this thesis the development of 3D ptychography is described. It includes the description of the required experimental environment, the numerical implementation of ptychographic phase retrieval and tomographic reconstruction routines, and a detailed analysis of the performance of 3D ptychography using an example of an experiment carried out at beamline P06 of PETRA III at DESY in Hamburg. In that experiment the investigated object was a Mo/UO2 thin film, which is a simplified model for spent nuclear fuel from nuclear power plant reactors. Such models find application in systematic scientific investigations related to the safe disposal of nuclear waste. We determined the three-dimensional interior structure of this sample with an unprecedented spatial resolution of at least 18 nm. The measurement of the fluorescence signal at each scan point of the ptychograms delivers the two- and three-dimensional elemental distribution of the sample with a spatial resolution of 80 nm. Using the fluorescence data, we assigned the chemical element to the area of the corresponding phase shift in the ptychographic reconstruction of the object phase and to the corresponding refractive index decrement in the tomographic reconstruction. The successful demonstration of the feasibility of the 3D ptychography motivates further applications, for instance, in the field of medicine, of material science, and of basic physical research.Kohärente Bildgebung ist eine vielversprechende Methode der Röntgenmikroskopie. Sie ermöglicht die zerstörungsfreie Bestimmung der inneren Struktur von strahlenharten Untersuchungsobjekten mit einer räumlichen Auflösung, die im Prinzip nur von der integralen Anzahl der Photonen auf der Probe sowie deren Streukraft abhängt. Letztendlich stellt die Wellenlänge der verwendeten Röntgenstrahlung eine Grenze für die erreichbare räumliche Auflösung dar. Die Kombination der kohärenten Bildgebung mit der Rastermikroskopie zur sogenannten Ptychographie eröffnet die Möglichkeit, auch ausgedehnte Objekte mit hoher Auflösung zu untersuchen. Dabei wird die Probe mit einem räumlich begrenzten, kohärenten Röntgenstrahl abgerastert und an jedem Rasterpunkt ein Beugungsbild von einer im Fernfeld platzierten Beugungskamera registriert. Die Beleuchtungen benachbarter Rasterpunkte müssen dabei zu einem bestimmten Prozentsatz überlappen, um genügend Informationen für eine anschließende computergestützte und eindeutige Rekonstruktion des Objektes sicherzustellen. Moderne Rekonstruktionsalgorithmen ermöglichen sogar die gleichzeitige Rekonstruktion der Transmissionsfunktion des Objektes und der Beleuchtungsfunktion des eintreffenden Röntgenstrahls. Die Verknüpfung der Ptychographie mit der Tomographie zur 3D-Ptychographie ist der nahe liegende Schritt, um nun auch die dreidimensionale innere Struktur von Objekten mit hoher räumlicher Auflösung zu bestimmen. Die Projektionen an den verschiedenen Winkelpositionen der Probe werden dabei mittels ptychographischer Abrasterung der Probe erzeugt und anschließend der tomographischen Rekonstruktion zugrunde gelegt. In dieser Arbeit wird die Entwicklung der 3D-Ptychographie beschrieben. Das beinhaltet die Beschreibung der experimentellen Umgebung, der numerischen Implementierung des ptychographischen und des tomographischen Rekonstruktionsalgorithmus als auch eine detaillierte Darstellung der Durchführung der 3D-Ptychographie am Beispiel eines Experiments, welches unter Verwendung des modernen Nanoprobe-Aufbaus des Strahlrohres P06 am PETRA III Synchrotronring des DESY in Hamburg durchgeführt wurde. Als Untersuchungsobjekt diente dabei ein dünner Mo/UO2-Film, der ein vereinfachtes Modell für die in Reaktoren von Atomkraftwerken verbrauchten Brennstäbe darstellt und deshalb im Bereich des Umweltschutzes Anwendung findet. Die dreidimensionale Struktur der Probe wurde mit einer - für diese Methode bisher einmaligen - räumlichen Auflösung von 18 nm bestimmt. Die Messung des von der Probe kommenden Fluoreszenz-Signals an jedem Rasterpunkt der Ptychogramme ermöglichte zusätzlich die Bestimmung der zwei- und dreidimensionalen Elementverteilung innerhalb der Probe mit einer räumlichen Auflösung von 80 nm. Anhand der Fluoreszenzdaten konnte sowohl den Bereichen verschiedener Phasenschübe in den ptychographischen Rekonstruktionen der Objektphase als auch den verschiedenen Werten des Dekrementes des Brechungsindex in der tomographischen Rekonstruktion, das entsprechende chemische Element zugeordnet werden. Die erfolgreiche Demonstration der Durchführbarkeit der 3D-Ptychographie motiviert weitere zukünftige Anwendungen, z. B. auf dem Gebiet der Medizin, der Materialforschung und der physikalischen Grundlagenforschung

La percepción del alemán multietnolectal de Zúrich: un continuo más que una categorización neta

Since about 2000, the emergence of so-called ‘multiethnolects’ has been observed among adolescents in German-speaking Switzerland; however, a systematic description of these varieties is lacking at present. The few existing perception studies of multiethnolects in other European countries are usually based on two or more predetermined groups that are compared. This paper investigates which labels are used for multiethnolectal Zurich German and how this way of speaking is perceived by adolescents; we adopt a perceptual sociolinguistics approach which focuses on the conceptualizations of lay people rather than on those of linguists. In a rating experiment, 40 adolescents listened to short speech samples of 48 pupils recorded in two different schools in the city of Zurich and were asked to rate the speakers on a 7-point Likert scale according to how multiethnolectal they sounded (not at all – very strongly). The results yielded a perceptual continuum rather than a clear-cut binary categorization [±multiethnolectal]. A smaller follow-up experiment with 12 adult raters (using the same stimuli) yielded a highly significant correlation between the mean rating scores of the two groups of raters.A partir del año 2000 aproximadamente se ha observado la aparición de los llamados ‘multietnolectos’ en la Suiza de habla alemana. Sin embargo, hasta el momento no existe una descripción sistemática de estas variedades lingüísticas. Los escasos estudios de percepción que se han realizado en otros países europeos se basan por lo general en la comparación de dos o más grupos preestablecidos. Este artículo investiga qué términos se utilizan para denominar el multietnolecto hablado en Zúrich y cómo un grupo adolescentes califican esta manera de hablar, adoptando, pues, un enfoque de sociolingüística perceptiva que se centra en las representaciones de locutores comunes más que de lingüistas. En un experimento de percepción, cuarenta adolescentes escucharon breves muestras de habla producidas por 48 escolares que habían sido grabadas en dos escuelas de la ciudad de Zúrich. La tarea de los oyentes consistió en calificar a los locutores con una escala de Likert de siete puntos según cómo de multietnolectal sonaba su habla (no en absoluto – muy fuertemente). Los resultados revelan la existencia de un continuum perceptivo más que de una categorización binaria [±multietnolectal]. El mismo experimento se realizó también con ocho oyentes adultos, obteniendo una correlación muy fuerte y altamente significativa con los valores de los oyentes adolescentes. Estos resultados sugieren que en la percepción del multietnolecto alemán de Zúrich no parece existir una diferencia entre una perspectiva etic y una perspectiva emic

Family-specific degenerate primer design: a tool to design consensus degenerated oligonucleotides

Designing degenerate PCR primers for templates of unknown nucleotide sequence may be a very difficult task. In this paper, we present a new method to design degenerate primers, implemented in family-specific degenerate primer design (FAS-DPD) computer software, for which the starting point is a multiple alignment of related amino acids or nucleotide sequences. To assess their efficiency, four different genome collections were used, covering a wide range of genomic lengths: Arenavirus ( nucleotides), Baculovirus ( to  bp), Lactobacillus sp. ( to  bp), and Pseudomonas sp. ( to  bp). In each case, FAS-DPD designed primers were tested computationally to measure specificity. Designed primers for Arenavirus and Baculovirus were tested experimentally. The method presented here is useful for designing degenerate primers on collections of related protein sequences, allowing detection of new family members.Fil: Iserte, Javier Alonso. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área de Virosis Emergentes y Zoonótica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Stephan, Betina Inés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área de Virosis Emergentes y Zoonótica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goñi, Sandra Elizabeth. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área de Virosis Emergentes y Zoonótica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Borio, Cristina Silvia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área de Virosis Emergentes y Zoonótica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ghiringhelli, Pablo Daniel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lozano, Mario Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular. Área de Virosis Emergentes y Zoonótica; Argentin

The 'Publicness-puzzle' in public leadership. A theoretical exploration of leadership in public organizations

Abstract Following a contingency approach we argue that the content and style of administrative leadership depends on characteristics of the public context. The purpose of the paper is to develop hypotheses on the relationships between several dimensions of publicness and the content and style of leadership, by reviewing academic literature on public leadership. To build our argument we first conceptualize leadership and distinguish several theories, definitions, and styles of leadership based on four different basic conceptions of what leadership is: Leadership as traits; 2. Leadership as behavior; 3. Leadership as managing of meaning; 4. Leadership as interaction processes. Then, Bozeman’s model of publicness is described as well as the effects of publicness on organizational environments, organizational goals, organizational structures and managerial values. As a final step we develop hypotheses that relate leadership to publicness and identify possible contradictory demands administrative leadership has to deal with. We conclude by outlining a research agenda on administrative leadership

The Impact of Exercise on Telomere Length, DNA Methylation and Metabolic Footprints

Aging as a major risk factor influences the probability of developing cancer, cardiovascular disease and diabetes, amongst others. The underlying mechanisms of disease are still not fully understood, but research suggests that delaying the aging process could ameliorate these pathologies. A key biological process in aging is cellular senescence which is associated with several stressors such as telomere shortening or enhanced DNA methylation. Telomere length as well as DNA methylation levels can be used as biological age predictors which are able to detect excessive acceleration or deceleration of aging. Analytical methods examining aging are often not suitable, expensive, time-consuming or require a high level of technical expertise. Therefore, research focusses on combining analytical methods which have the potential to simultaneously analyse epigenetic, genomic as well as metabolic changes

Evolving genealogies for branching populations under selection and competition

For a continuous state branching process with two types of individuals which are subject to selection and density dependent competition, we characterize the joint evolution of population size, type configurations and genealogies as the unique strong solution of a system of SDE's. Our construction is achieved in the lookdown framework and provides a synthesis as well as a generalization of cases considered separately in two seminal papers by Donnelly and Kurtz (1999), namely fluctuating population sizes under neutrality, and selection with constant population size. As a conceptual core in our approach, we introduce the selective lookdown space which is obtained from its neutral counterpart through a state-dependent thinning of "potential" selection/competition events whose rates interact with the evolution of the type densities. The updates of the genealogical distance matrix at the "active" selection/competition events are obtained through an appropriate sampling from the selective lookdown space. The solution of the above mentioned system of SDE's is then mapped into the joint evolution of population size and symmetrized type configurations and genealogies, i.e. marked distance matrix distributions. By means of Kurtz's Markov mapping theorem, we characterize the latter process as the unique solution of a martingale problem. For the sake of transparency we restrict the main part of our presentation to a prototypical example with two types, which contains the essential features. In the final section we outline an extension to processes with multiple types including mutation

Copper in Wood Preservatives Delayed Wood Decomposition and Shifted Soil Fungal but Not Bacterial Community Composition

Copper-based fungicides are routinely used for wood and plant protection, which can lead to an enrichment of copper-tolerant microbial communities in soil. To investigate the effect of such wood preservatives on the soil fungal and bacterial community compositions, five different vineyard and fruit-growing soil environments were evaluated using incubation studies over time. Pine sapwood specimens were impregnated with either water or different biocide treatment solutions containing a mixture of copper, triazoles, and quaternary ammonium compounds (CuTriQAC), a mixture of triazoles and quaternary ammonium compounds (TriQAC), or copper alone (Cu). Specimens were incubated in soil from each sample site for 8, 16, 24, and 32 weeks. The effects of preservative treatment on the modulus of elasticity (MOE) of the wood specimens and on the soil fungal as well as bacterial community composition at the soil-wood interface were assessed by quantitative PCR and amplicon sequencing of the fungal internal transcribed spacer (ITS) region and bacterial 16S rRNA gene. Specimens impregnated with CuTriQAC and Cu showed decreased MOE and reduced fungal and bacterial copy numbers over time compared to those impregnated with water and TriQAC. Fungal but not bacterial community composition was significantly affected by wood preservative treatment. The relative abundance of members of the family Trichocomaceae compared to other genera increased in the presence of the Cu and CuTriQAC treatments at three sites, suggesting these to be Cu-tolerant fungi. In conclusion, the copper-containing treatments resulted in marginally increased MOE, lowered microbial gene copy numbers compared to those in the TriQAC and water treatments, and thus enhanced wood protection against soil microbial wood degradation

A case of homicidal intraoral gunshot and review of the literature

Determination of the manner of death in case of intraoral firearm wounds can be a challenge, especially if the circumstances of the incident are unclear and crime scene investigation is inadequate. It is a well-known fact that the mouth is one of the selected sites for suicide with firearms. Homicidal shooting through the mouth is said to be rare, but does occur, and can be mistaken for a suicide. For discrimination between suicide and homicide in cases of intraoral firearm wounds, some useful points are the site of entry wound, the direction of the internal bullet path, the range of fire and the circumstances of death. We demonstrate these points in a case of a homicidal gunshot to the mouth assessed by both classical autopsy and post-mortem CT (PMCT