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Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60%) Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_s=|\phi_t-\psi_{\rm EP}|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $p_T$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with $\phi_s$, with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity $\Delta\eta$ correlation) appears to drop with increasing $\phi_s$ while the jet-like component remains approximately constant. The correlation functions are further studied with subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the $\phi_s$-dependence of the ridge or the away-side double-peak structure. ..., Comment: 54 pages, 40 figures, 6 tables. As published

Frontotemporal dementia is a group of early onset dementia syndromes linked to underlying frontotemporal lobar degeneration (FTLD) pathology that can be classified based on the formation of abnormal protein aggregates involving tau and two RNA binding proteins, TDP-43 and FUS. Although elucidation of the mechanisms leading to FTLD pathology is in progress, recent advances in genetics and neuropathology indicate that a majority of FTLD cases with proteinopathy involving RNA binding proteins show highly congruent genotype-phenotype correlations. Specifically, recent studies have uncovered the unique properties of the low-complexity domains in RNA binding proteins that can facilitate liquid-liquid phase separation in the formation of membraneless organelles. Furthermore, there is compelling evidence that mutations in FTLD genes lead to dysfunction in diverse cellular pathways that converge on the endolysosomal pathway, autophagy, and neuroinflammation. Together, these results provide key mechanistic insights into the pathogenesis and potential therapeutic targets of FTLD.

Einleitung: Die nichtinterventionelle Studie (NIS) ARATA (NCT02251860) beobachtet über 2 Jahre das klinische Ansprechen und die Therapiesicherheit einer subkutanen RoActemra® (Tocilizumab [TCZ] s.c.) Therapie unter Routinebedingungen. In dieser Interimsanalyse wurden Patienten getrennt[zum vollständigen Text gelangen Sie über die oben angegebene URL], 45. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh), 31. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh), 27. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

Einleitung: Tocilizumab (TCZ) wurde in klinischen Studien primär mit und ohne Methotrexat (MTX) Begleitmedikation untersucht. In der klinischen Praxis werden auch andere sDMARD Kombinationspartner (z.B. Leflunomid, LEF) eingesetzt. In der aktuellen Interimsanalyse (Stichtag 03.12.2015) der nicht-interventionellen[zum vollständigen Text gelangen Sie über die oben angegebene URL], 44. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 30. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 26. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

Einleitung: In klinischen Studien erzielte Tocilizumab (TCZ) mit und ohne sDMARD Begleittherapie eine vergleichbare Wirksamkeit. In dieser Interimsanalyse der nicht-interventionellen Studie ICHIBAN wurde untersucht: Unterscheiden sich die Schnelligkeit im Erreichen sowie die Dauer einer DAS28-BSG Remission[zum vollständigen Text gelangen Sie über die oben angegebene URL], 44. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 30. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 26. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

Einleitung: In der ARATA Studie soll über 2 Jahren das klinische Ansprechen und die Therapiesicherheit einer RoActemra® subkutan (Tocilizumab (TCZ) s.c.) Therapie unter Routinebedingungen beobachtet werden. In dieser Interimsanalyse wurde die Effektivität der Therapie im ersten Behandlungsjahr[zum vollständigen Text gelangen Sie über die oben angegebene URL], 44. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 30. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 26. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

Einleitung: Gemäß WHO-Definition leiden ca. 15% aller Patienten mit rheumatoider Arthritis (RA) unter einer Anämie (Hämoglobin, 43. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 29. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 25. wissenschaftliche Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

Einleitung: In der ARATA-Studie soll über eine Beobachtungszeit von 2 Jahren das klinische Ansprechen sowie die Therapiesicherheit einer RoActemra® s.c. (Tocilizumab (TCZ) s.c.) Therapie unter Routinebedingungen beobachtet werden. TCZ-naive Patienten mit rheumatoider Arthritis (RA), die auf[zum vollständigen Text gelangen Sie über die oben angegebene URL], 43. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 29. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 25. wissenschaftliche Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

International audience

Background: Normal fluctuations in disease-activity measurements are issues for evaluation of a therapeutic-response in daily practice in rheumatoid arthritis (RA) patients. To address this aspect we established a statistical approach to determine a critical difference (dcrit) that defines valid criterion[for full text, please go to the a.m. URL], 42. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh); 28. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh); 24. wissenschaftliche Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

International audience; Background and Aims The extent to which the carbohydrate source-sink ratio influences the time of veraison of different Vitis viniferaL. cultivars was studied for Sauvignon Blanc and Pinot Noir. The aims were to: (i) determine how changing the leaf area: fruit mass (LA:FM) ratio shortly after fruitset alters the timing of veraison; (ii) establish the relative importance of adjusting the vine yield or the leaf area on the timing of veraison; and (iii) evaluate the relative effect on the timing of veraison, leaf area and yield parameters of the two cultivars at similar LA:FM ratios. Methods and Results Four cane, vertical shoot positioned trained vines were trimmed shortly after fruitset to retain six or 12 leaves per shoot and thinned by removing 0, 50 or 75% of the bunches. The timing of veraison was assessed by colour change for Pinot Noir, berry softness for Sauvignon Blanc and the day at which a mean of 8 degrees Brix was reached for both cultivars. Manipulating leaf area had a greater effect on the date of veraison than crop removal, which had no effect, except when vines were trimmed to six leaves. Sauvignon Blanc was always later than Pinot Noir for the time to reach 8 degrees Brix at all LA:FM ratio manipulations. Conclusions Restricting potential carbohydrate sources post-flowering delayed veraison, while removing crop had less influence. Significance of the Study Reduced leaf area can delay the time of veraison, which could counter the earlier timing that could occur from climate change or warmer than average seasons. Conversely, increased leaf area could enable target soluble solids to be achieved in cooler seasons.

The collective migration of cells is fundamental to epithelial biology. One of the hallmarks of collective behavior in migrating cohesive epithelial cell sheets is the emergence of so called leader cells. These cells exhibit a distinct morphology with a large and highly active lamellipodium. Although it is generally accepted that they play a crucial part in collective migration, the biophysical factors that regulate their formation remain unknown.Here we show that a geometry-based cue like local variation of curvature of the collective's perimeter is capable of triggering leader cell formation and promoting enhanced motility at defined positions. Remarkably, the extent of this effect scales with the magnitude of the curvature.Cytoskeletal tension was found to be important for geometry induced leader cell formation, as cells treated with tension reducing agents appeared less sensitive to local curvature variation. Accordingly, traction force microscopy revealed an increased level of shear stress at highly curved positions even before the cell migration had actually started, indicating the presence of a collective polarization induced by the geometry of the confinement.Together our findings suggest that high curvature leads to locally increased stress accumulation, mediated via cell-substrate interaction as well as via cytoskeleton tension. The stress accumulation in turn enhances the probability of leader cell formation as well as cell motility. This work defines the importance of geometric cue such as local curvature in the collective migration dynamics of epithelial cells and thus shows implications for the biophysical regulation of epithelium during wound healing, embryonic development, and oncogenesis.

We investigate the class of root systems $R$ obtained by extending an $A_1$-type irreducible root system by a free abelian group $G$. In this context there is a Weyl group $W$ and a group $U$ with the presentation by conjugation. Both groups are reflection groups with respect to a discrete symmetric space $T$ associated to $R$. We show that the natural homomorphism $U\to W$ is an isomorphism if and only if an associated subset $T^{ab}\setminus\{0\}$ of $G_2=G/2G$ is 2-independent, i.e. its image under the map $G_2\to G_2\otimes G_2, g\mapsto g\otimes g$ is linearly independent over the Galois field $F_2$.

We investigate the class of root systems R obtained by extending an irreducible root system by a torsion-free group G. In this context there is a Weyl group W and a group U with the presentation by conjugation. We show under additional hypotheses that the kernel of the natural homomorphism from U to W is isomorphic to the kernel of the homomorphism from the abelianization of U to that of W. For this we introduce the concept of a symmetric system, a discrete version of the concept of a symmetric space. Mathematics Subject Classification 2000: 20F55, 17B65, 17B67, 22E65, 22E40. Key Words and Phrases: Weyl group, root system, presentation by conjugation, extended affine Weyl group (EAWeG), extended affine root system (EARS), irreducible root system extended by an abelian group., 38 pages

International audience; The origin of chemically and isotopically enriched basalts along mid-ocean ridges (E-MORB) has been the subject of recent interest, particularly in cases where they are not related to a specific mantle plume. We present new isotope dilution analyses for Th, U, La, Ce, and Pb in 26 mostly glassy tholeiite samples dredged from the Mid-Atlantic Ridge (MAR) between 10° and 24°N. We interpret these data in combination with other previously published trace element data and isotope ratios for the same samples. We focus on the region at 14°–15°N, where incompatible trace element abundances are enriched by as much as factors of 40, relative to the depleted basalts found to the north and the south of this region. We invoke simple recycling of alkali basalts found on oceanic islands and seamounts as an alternative E-MORB origin to a recently published metasomatic enrichment model. A small amount of recycled alkali basalt is added to the local depleted mantle peridotite. Melting of such mixed sources can produce the observed E-MORB at 14°–15°N MAR and elsewhere. The bulk partition coefficients of Nb, Ta, K, and Pb (relative to other trace elements) are geochemically important because these elements are widely used as tracers of source chemistry. We evaluate their partitioning using simple log-log plots, and we compare the 10°–24° MAR basalts with a similar suite from the CIR 18°–20°S. In both suites, Nb (bulk) partitioning is close to Th, and Pb is close to Pr. Tantalum partitioning is also very close to Nb in the MAR setting but between U and K in the CIR setting. Potassium is slightly more compatible than U in the MAR suite but less compatible in the CIR setting. Thus, although the bulk partition coefficients of these elements do vary slightly in different regions, their overall consistency is remarkable considering that the partitioning of the individual elements is governed by different mineral phases.

We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA-ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high-precision bulk techniques, such as TIMS and MC-ICPMS. In addition, LA-ICPMS and SIMS isotope data of B, Li, and Pb are presented.

Oxygen isotope ratios in phenocrysts from ocean island basalts (OIB) can place constraints on the origins of their mantle sources. Values of δ^(18)O in olivines from alkali basalts from Pitcairn Island (which have the extreme "EM1" signature based on radiogenic isotopes) are equal to those of olivines from average mantle peridotite (based on studies of mantle xenoliths and the MORB source region) . This result suggests that the amount of recycled continental sediment in Pitcairn Island EM1 sources is less than ~0.75%. Based on studies of olivine phenocrysts, the sources of both the plume component of Hawaiian lavas and of all measured Juan Fernandez ("PHEM") samples also have oxygen isotope compositions indistinguishable from average upper mantle peridotite. If these OIB sources come from the lower mantle, it is implied to have an oxygen isotope ratio similar to the upper mantle. Low ^(18)O/^(16)O olivines from some Hawaiian lavas are associated with a more MORB-like He and radiogenic isotope component, possibly recycled but also consistent with contamination from the base of the modern Pacific plate.

The bacterial strains Rhodococcus (opacus) erythropolis HL PM-1 and Nocardioides simplex FJ2-1A can use picric acid (TNP) and 2,4-dinitrophenol (DNP) as sole nitrogen source. Enzymes were identified which are isofunctional in both strains, using the same degradation mechanism. During the initial steps hydride ions were transferred to the aromatic ring of the electron deficient p-system, forming first the hydride s-complex of TNP, H--TNP, and subsequently the dihydride s-complex, 2H--TNP. The reactions were catalyzed by hydride transferase II (HTII) and hydride transferase I (HTI), respectively, together with the NADPH-dependent F420 reductase (NDFR) and the coenzymes NADPH and F420. NDFR, HTII, and HTI were cloned and purified as His-tag fusion proteins by Ni-NTA affinity chromatography. Reactions were followed by repeated recording of UV-visible spectra, and intermediates were identified by HPLC, HPLC-MS, and NMR measurements. H--TNP and 2H--TNP were chemically synthesized and used as standards and substrates. In the next step, a nitrite-eliminating enzyme releasing nitrite from 2H--TNP and generating the hydride s-complex of DNP (H--DNP) was identified. A tautomerase was shown to give rise to two tautomeric forms, the aci-nitro form and the nitro form of 2H--TNP, identified by HPLC and NMR measurements. Since the nitrite-eliminating enzyme used only the aci-nitro form as a substrate, it appears that the 2H--TNP tautomerase inhibits accumulation of the nitro form. Whereas the 2H--TNP tautomerase was cloned and purified as a His-tag fusion protein, the nitrite-eliminating enzyme was isolated by FPLC and the N-terminal sequence was determined. Databank search exhibited no similarities to any known proteins. HTI and NDFR, together with the coenzymes NADPH and F420, hydrogenated chemically synthesized H--DNP to 2H--DNP. It was shown by HPLC-MS that 2,4-dinitrocyclohexanone (2,4-DNCH) was generated after protonation. A hydrolase was purified by FPLC, catalyzing hydrolytic ring fission of 2,4-DNCH, forming 4,6-dinitrohexanoate (4,6-DNH). 4,6-DNH was identified by HPLC-MS. MALDI-TOF measurements showed that the 2,4-DNCH hydrolase consists of four identical subunits. Since determination of the N-terminal amino acid sequence exhibited that the corresponding gene was located on the known gene clusters of both strains, the gene function was recognized. Activity for the conversion of 4,6-DNH in crude extracts identified 4,6-DNH as a true intermediate of the degradation pathway of TNP and DNP., Die Bakterienstämme Rhodococcus (opacus) erythropolis HL PM-1 und Nocardioides simplex FJ2-1A können Pikrinsäure (TNP) und 2,4-Dinitrophenol (DNP) als alleinige Stickstoffquelle nutzen. Dabei wurden Enzyme eines konvergenten Abbauwegs nachgewiesen, die in beiden Stämmen isofunktionell sind. Während der Initialschritte wird Hydrid auf den aromatischen Ring des elektronenarmen p-Systems übertragen, wobei sich zeigte, dass zuerst der Hydrid-s-Komplex von TNP, H--TNP, und in einer nachfolgenden Hydridübertragung der Dihydrid-s-Komplex, 2H--TNP, entsteht. Die Reaktionen werden von zwei Hydridtransferasen, HTII und HTI, katalysiert, wobei die NADPH-abhängige F420-Reduktase (NDFR) und die Coenzyme NADPH und F420 für den Umsatz notwendig sind. NDFR, HTII und HTI wurden kloniert und als His-tag-Proteine mittels Ni-NTA-Affinitätschromatographie gereinigt. Die Reaktionen wurden mit Hilfe von UV/Vis-Spektren in zeitlichen Abständen von jeweils einer Minute verfolgt und die Metabolite mit HPLC-MS und NMR-Messungen nachgewiesen. H--TNP und 2H--TNP wurden chemisch synthetisiert, um sie sowohl als Standard sowie als Substrat einsetzen zu können. Im folgenden Abbauschritt wird durch ein Nitrit-eliminierendes Enzym eine Nitro-Gruppe aus 2H--TNP in Form von Nitrit abgespaltet, wobei der Hydrid-s-Komplex von DNP (H--DNP) entsteht. Eine Tautomerase isomerisiert 2H--TNP zu zwei Tautomeren, die Aci-nitro- und die Nitro-Form. Dies wurde durch HPLC-MS und NMR-Messungen bestätigt. Da das Nitrit-eliminierende Enzym nur die Aci-nitro-Form umsetzen kann, verhindert die 2H--TNP-Tautomerase, dass die Nitro-Form als nicht weiter abzubauendes Produkt akkumuliert. Während die 2H--TNP-Tautomerase kloniert und als His-tag-Protein gereinigt wurde, konnte das Nitrit-eliminierende Enzym mittels FPLC isoliert, und die N-terminale Aminosäuresequenz bestimmt werden. Datenbank-Recherchen ergaben keine Ähnlichkeiten zu bekannten Enzymen. Die HTI und NDFR, zusammen mit den Coenzymen NADPH und F420, hydrierten chemisch synthetisiertes H--DNP zu 2H--DNP. Es zeigte sich, dass anschließend durch Protonierung spontan 2,4-Dinitrocyclohexanon (2,4-DNCH) entstand, was durch HPLC-MS-Messungen gezeigt wurde. Mittels FPLC wurde eine Hydrolase gereinigt, die eine hydrolytische Ringöffnung von 2,4-DNCH katalysierte, was zu 4,6-Dinitrohexanoat (4,6-DNH) als Produkt führte. 4,6-DNH konnte mit Hilfe von HPLC-MS-Messungen nachgewiesen werden. MALDI-TOF-Messungen ergaben, dass die 2,4-DNCH-Tautomerase wahrscheinlich als Tetramer mit vier identischen Untereinheiten vorliegt. Da die Bestimmung der N-terminalen Aminosäuresequenz der 2,4-DNCH-Hydrolase zeigte, dass das entsprechende Gen auf dem jeweils bekannten Gen-Cluster in beiden Stämmen zu finden war, konnte diesem Gen erstmalig eine Funktion nachgewiesen werden. Umsatzaktivitäten für 4,6-DNH mit Rohextrakt identifizierten 4,6-DNH als echtes Intermediat im Abbauweg von TNP und DNP.

The bacterial strains Rhodococcus (opacus) erythropolis HL PM-1 and Nocardioides simplex FJ2-1A can use picric acid (TNP) and 2,4-dinitrophenol (DNP) as sole nitrogen source. Enzymes were identified which are isofunctional in both strains, using the same degradation mechanism. During the initial steps hydride ions were transferred to the aromatic ring of the electron deficient p-system, forming first the hydride s-complex of TNP, H--TNP, and subsequently the dihydride s-complex, 2H--TNP. The reactions were catalyzed by hydride transferase II (HTII) and hydride transferase I (HTI), respectively, together with the NADPH-dependent F420 reductase (NDFR) and the coenzymes NADPH and F420. NDFR, HTII, and HTI were cloned and purified as His-tag fusion proteins by Ni-NTA affinity chromatography. Reactions were followed by repeated recording of UV-visible spectra, and intermediates were identified by HPLC, HPLC-MS, and NMR measurements. H--TNP and 2H--TNP were chemically synthesized and used as standards and substrates. In the next step, a nitrite-eliminating enzyme releasing nitrite from 2H--TNP and generating the hydride s-complex of DNP (H--DNP) was identified. A tautomerase was shown to give rise to two tautomeric forms, the aci-nitro form and the nitro form of 2H--TNP, identified by HPLC and NMR measurements. Since the nitrite-eliminating enzyme used only the aci-nitro form as a substrate, it appears that the 2H--TNP tautomerase inhibits accumulation of the nitro form. Whereas the 2H--TNP tautomerase was cloned and purified as a His-tag fusion protein, the nitrite-eliminating enzyme was isolated by FPLC and the N-terminal sequence was determined. Databank search exhibited no similarities to any known proteins. HTI and NDFR, together with the coenzymes NADPH and F420, hydrogenated chemically synthesized H--DNP to 2H--DNP. It was shown by HPLC-MS that 2,4-dinitrocyclohexanone (2,4-DNCH) was generated after protonation. A hydrolase was purified by FPLC, catalyzing hydrolytic ring fission of 2,4-DNCH, forming 4,6-dinitrohexanoate (4,6-DNH). 4,6-DNH was identified by HPLC-MS. MALDI-TOF measurements showed that the 2,4-DNCH hydrolase consists of four identical subunits. Since determination of the N-terminal amino acid sequence exhibited that the corresponding gene was located on the known gene clusters of both strains, the gene function was recognized. Activity for the conversion of 4,6-DNH in crude extracts identified 4,6-DNH as a true intermediate of the degradation pathway of TNP and DNP., Die Bakterienstämme Rhodococcus (opacus) erythropolis HL PM-1 und Nocardioides simplex FJ2-1A können Pikrinsäure (TNP) und 2,4-Dinitrophenol (DNP) als alleinige Stickstoffquelle nutzen. Dabei wurden Enzyme eines konvergenten Abbauwegs nachgewiesen, die in beiden Stämmen isofunktionell sind. Während der Initialschritte wird Hydrid auf den aromatischen Ring des elektronenarmen p-Systems übertragen, wobei sich zeigte, dass zuerst der Hydrid-s-Komplex von TNP, H--TNP, und in einer nachfolgenden Hydridübertragung der Dihydrid-s-Komplex, 2H--TNP, entsteht. Die Reaktionen werden von zwei Hydridtransferasen, HTII und HTI, katalysiert, wobei die NADPH-abhängige F420-Reduktase (NDFR) und die Coenzyme NADPH und F420 für den Umsatz notwendig sind. NDFR, HTII und HTI wurden kloniert und als His-tag-Proteine mittels Ni-NTA-Affinitätschromatographie gereinigt. Die Reaktionen wurden mit Hilfe von UV/Vis-Spektren in zeitlichen Abständen von jeweils einer Minute verfolgt und die Metabolite mit HPLC-MS und NMR-Messungen nachgewiesen. H--TNP und 2H--TNP wurden chemisch synthetisiert, um sie sowohl als Standard sowie als Substrat einsetzen zu können. Im folgenden Abbauschritt wird durch ein Nitrit-eliminierendes Enzym eine Nitro-Gruppe aus 2H--TNP in Form von Nitrit abgespaltet, wobei der Hydrid-s-Komplex von DNP (H--DNP) entsteht. Eine Tautomerase isomerisiert 2H--TNP zu zwei Tautomeren, die Aci-nitro- und die Nitro-Form. Dies wurde durch HPLC-MS und NMR-Messungen bestätigt. Da das Nitrit-eliminierende Enzym nur die Aci-nitro-Form umsetzen kann, verhindert die 2H--TNP-Tautomerase, dass die Nitro-Form als nicht weiter abzubauendes Produkt akkumuliert. Während die 2H--TNP-Tautomerase kloniert und als His-tag-Protein gereinigt wurde, konnte das Nitrit-eliminierende Enzym mittels FPLC isoliert, und die N-terminale Aminosäuresequenz bestimmt werden. Datenbank-Recherchen ergaben keine Ähnlichkeiten zu bekannten Enzymen. Die HTI und NDFR, zusammen mit den Coenzymen NADPH und F420, hydrierten chemisch synthetisiertes H--DNP zu 2H--DNP. Es zeigte sich, dass anschließend durch Protonierung spontan 2,4-Dinitrocyclohexanon (2,4-DNCH) entstand, was durch HPLC-MS-Messungen gezeigt wurde. Mittels FPLC wurde eine Hydrolase gereinigt, die eine hydrolytische Ringöffnung von 2,4-DNCH katalysierte, was zu 4,6-Dinitrohexanoat (4,6-DNH) als Produkt führte. 4,6-DNH konnte mit Hilfe von HPLC-MS-Messungen nachgewiesen werden. MALDI-TOF-Messungen ergaben, dass die 2,4-DNCH-Tautomerase wahrscheinlich als Tetramer mit vier identischen Untereinheiten vorliegt. Da die Bestimmung der N-terminalen Aminosäuresequenz der 2,4-DNCH-Hydrolase zeigte, dass das entsprechende Gen auf dem jeweils bekannten Gen-Cluster in beiden Stämmen zu finden war, konnte diesem Gen erstmalig eine Funktion nachgewiesen werden. Umsatzaktivitäten für 4,6-DNH mit Rohextrakt identifizierten 4,6-DNH als echtes Intermediat im Abbauweg von TNP und DNP.

Goal of the ATRAP - Experiment is to capture the simplest atoms of antimatter, the Anti-Hydrogen-Atom $\overline{H}^{0}$ in a trap, where it can be cooled and detected in order to perform high precision optical spectroscopy. Subject of this work are studies in preparation of the construction of the ASPIRIN-Detector being a realtime imaging Antihydrogen Annihilation Detector in the ATRAP - Experiment. Monte-Carlo-Simulations were performed in order to optimize efficiency and spatial resolution. Main part of the detector will be a cylindrical fibre hodoscope, consisting of several layers of differently oriented fibres allowing spatial resolution. Light output and attenuation length of the fibres were measured and the influence of low temperature was tested. 16-channel multi-anode photomultipliers for the fibre readout were tested, focussing an gain, crosstalk and dank counts. The perfomance of the tubes in magnetic field was studied. The following conclusions are drawn: The material between the annihilation point and the ASPIRIN-Detector should not exceed 3 mm copper, in order to maintain a satisfying spatial resolution. Scintillation does not freeze out under liquid - Helium - temperature, hence scintillating fibres are suitable for the Experiment. The fibres should not guide the light more then 1,5 m since the average attenuation length is of this order. The Photomultiplier tube H6568 of the manufacturer Hamamatsu is capable for the readout of the fibres, but raust be coated with magnetic shielding reducing the field to values below 10G.

Drilling during ODP Leg 158 took place on the active mound of the TAG hydrothermal field on the Mid-Atlantic Ridge. The dominant mineral precipitating from the hydrothermal fluid is pyrite. Its Re and Os concentration and the Os isotopic composition provide constraints on the nature of the hydrothermal fluid circulating in the TAG mound. The 187Os/186Os ratios of massive pyrite samples vary from 4.9 to 8.9. The highest ratios have been observed in the upper part of the sulfide mountain (