Approximation by the Dickman distribution and quasi-logarithmic combinatorial structures

Quasi-logarithmic combinatorial structures are a class of decomposable combinatorial structures which extend the logarithmic class considered by Arratia, Barbour and Tavar\'{e} (2003). In order to obtain asymptotic approximations to their component spectrum, it is necessary first to establish an approximation to the sum of an associated sequence of independent random variables in terms of the Dickman distribution. This in turn requires an argument that refines the Mineka coupling by incorporating a blocking construction, leading to exponentially sharper coupling rates for the sums in question. Applications include distributional limit theorems for the size of the largest component and for the vector of counts of the small components in a quasi-logarithmic combinatorial structure.Comment: 22 pages; replaces earlier paper [arXiv:math/0609129] with same title by Bruno Nietlispac

Asymptotic density in quasi-logarithmic additive number systems

We show that in quasi-logarithmic additive number systems \mycal{A} all partition sets have asymptotic density, and we obtain a corresponding monadic second-order limit law for adequate classes of relational structures. Our conditions on the local counting function p(n) of the set of irreducible elements of \mycal{A} allow situations which are not covered by the density theorems of Compton [6] and Woods [15]. We also give conditions on p(n) which are sufficient to show the assumptions of Compton's result are satisfied, but which are not necessarily implied by those of Bell and Burris [2], Granovsky and Stark [8] or Stark [14

Soil biological quality in short- and long-term field trials with conventional and organic fertility input types

Soils of the DOK trial and three other field trials with manure input were analysed for effects on soil biology. While long-term effects indicate a new steady state at the DOK trial site, differences at the other field trials suggest that fresh manure at the Bonn trial and chicken manure at the UK sites are at least temporarily advantageous, probably due to their relatively fast mineralization

Improving resolution in multidimensional NMR using random quadrature detection with compressed sensing reconstruction.

NMR spectroscopy is central to atomic resolution studies in biology and chemistry. Key to this approach are multidimensional experiments. Obtaining such experiments with sufficient resolution, however, is a slow process, in part since each time increment in every indirect dimension needs to be recorded twice, in quadrature. We introduce a modified compressed sensing (CS) algorithm enabling reconstruction of data acquired with random acquisition of quadrature components in gradient-selection NMR. We name this approach random quadrature detection (RQD). Gradient-selection experiments are essential to the success of modern NMR and with RQD, a 50 % reduction in the number of data points per indirect dimension is possible, by only acquiring one quadrature component per time point. Using our algorithm (CSRQD), high quality reconstructions are achieved. RQD is modular and combined with non-uniform sampling we show that this provides increased flexibility in designing sampling schedules leading to improved resolution with increasing benefits as dimensionality of experiments increases, with particular advantages for 4- and higher dimensional experiments.Part of this work was performed using the Darwin Supercomputer of the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/), provided by Dell Inc. using Strategic Research Infrastructure Funding from the Higher Education Funding Council for England and funding from the Science and Technology Facilities Council.This is the final version of the article. It first appeared from Springer via https://doi.org/10.1007/s10858-016-0062-

Kathetergestützte Aortenklappenimplantation: Was müssen Anästhesisten wissen?

Zusammenfassung: Der chirurgische Aortenklappenersatz gilt als Goldstandard in der Therapie der hochgradigen Aortenklappenstenose. Die veränderte Demografie konfrontiert die behandelnden medizinischen Fachdisziplinen jedoch mit einem zunehmend höheren Risikoprofil der Patienten; dies machte die Entwicklung neuer weniger invasiver Behandlungsalternativen in der operativen Therapie der Aortenklappenstenose erforderlich. Dieser Entwicklungsprozess führte über die Minithorakotomie hin zur kathetergestützten Aortenklappenimplantation ("transcatheter aortic valve implantation", TAVI). Die TAVI ist ein neues therapeutisches Verfahren zur Behandlung von Patienten mit hochgradiger Aortenklappenstenose und hohem perioperativen Morbiditäts- sowie Mortalitätsrisiko für einen konventionellen Aortenklappenersatz. Da die TAVI am schlagenden Herzen ohne Sternotomie und Herz-Lungen-Maschine durchgeführt werden kann, eignet sich dieses Verfahren insbesondere für den älteren, multimorbiden und/oder kardial voroperierten Patienten. Die ersten Ergebnisse großer prospektiver Multizenterstudien unterstreichen den Stellenwert der TAVI in der modernen Behandlung von Hochrisikopatienten mit symptomatischer Aortenklappenstenose. Die TAVI erfordert vom Anästhesisten neben dem Verständnis des chirurgischen Ablaufs die genaue Kenntnis des perioperativen anästhesiologischen Managements und der möglichen Komplikationen des Verfahren

Erhöhte Trockenstresstoleranz von Kleegras nach reduzierter Bodenbearbeitung

Grass-clover leys are an integral part of organic rotations. We performed an experiment with reduced tillage (RT) and conventional tillage (CT) using mouldboard ploughing in a rotation in Frick (Switzerland) on a heavy soil and 1000 mm mean annual precipitation. The grass-clover mixture was sawn in autumn 2005 after uniform seed bed preparation with a rotary hoe in both tillage systems without ploughing. After emergence most of the clover seedlings collapsed in the CT plots due to draught, while they survived in the RT plots. This led to a much higher share of clover in the mixture under RT. Grass-clover yields were 29 and 23% higher in RT than in CT plots in the first and second year of cultivation in 2006 and 2007, respectively. Grass grown in RT plots was higher in nitrogen (N), phosphorous (P), potassium (K) and magnesium (Mg) content than in CT plots; clover contained solely more P in RT plots. Over all grass-clover had better growing conditions in RT compared to CT plots in our experiment, reflecting after-effects of the differentiated tillage schemes applied for the preceding arable crops. It is suggested that reduced tillage has a high potential to improve water stress tolerance of cropping systems

Klimafreundlicher Bioackerbau auf schweren Böden (Exaktversuch Frick)

Versuchsfragen Langfristige Auswirkungen auf Bodenfruchtbarkeit und Ertrag bei: ❯ Reduzierter Bodenbearbeitung vs Pfl ug ❯ Vollgülle vs Mistkompost/Gülle ❯ Mit vs ohne biologisch-dynamische Präparate Questions expérimentales Conséquences à long terme sur la fertilité du sol et le rendement en cas de: ❯ Travail réduit du sol par rapport au labourage ❯ Lisier complet vs. compost fumier/lisier ❯ Avec ou sans préparation biodynamique

Application of random coherence order selection in gradient-enhanced multidimensional NMR

Development of multidimensional NMR is essential to many applications, for example in high resolution structural studies of biomolecules. Multidimensional techniques enable separation of NMR signals over several dimensions, improving signal resolution, whilst also allowing identification of new connectivities. However, these advantages come at a significant cost. The Fourier transform theorem requires acquisition of a grid of regularly spaced points to satisfy the Nyquist criterion, while frequency discrimination and acquisition of a pure phase spectrum require acquisition of both quadrature components for each time point in every indirect (non-acquisition) dimension, adding a factor of 2$^{N−1}$ to the number of free-induction decays which must be acquired, where $N$ is the number of dimensions. Compressed sensing (CS) ℓ$_{1}$-norm minimisation in combination with non-uniform sampling (NUS) has been shown to be extremely successful in overcoming the Nyquist criterion. Previously, maximum entropy reconstruction has also been used to overcome the limitation of frequency discrimination, processing data acquired with only one quadrature component at a given time interval, known as random phase detection (RPD), allowing a factor of two reduction in the number of points for each indirect dimension (Maciejewski et al. 2011 $\small \textit{PNAS}$ 108 16640). However, whilst this approach can be easily applied in situations where the quadrature components are acquired as amplitude modulated data, the same principle is not easily extended to phase modulated (P-/N-type) experiments where data is acquired in the form exp ($\textit{iωt}$) or exp (−$\textit{iωt}$), and which make up many of the multidimensional experiments used in modern NMR. Here we demonstrate a modification of the CS ℓ$_1$-norm approach to allow random coherence order selection (RCS) for phase modulated experiments; we generalise the nomenclature for RCS and RPD as random quadrature detection (RQD). With this method, the power of RQD can be extended to the full suite of experiments available to modern NMR spectroscopy, allowing resolution enhancements for all indirect dimensions; alone or in combination with NUS, RQD can be used to improve experimental resolution, or shorten experiment times, of considerable benefit to the challenging applications undertaken by modern NMR.This is the final version of the article. It first appeared from IOP Publishing via http://dx.doi.org/10.1088/1742-6596/699/1/01200

Investigation of the TOCA1-Cdc42 interaction

Transducer of Cdc42-dependent actin assembly protein 1 (TOCA1) is an effector of the Rho family small G protein Cdc42. It contains a membrane-deforming F-BAR domain as well as a Src homology 3 (SH3) domain and a G protein-binding homology region 1 (HR1) domain. TOCA1 binding to Cdc42 leads to actin rearrangements, which are thought to be involved in processes such as endocytosis, filopodia formation, and cell migration. We have solved the structure of the HR1 domain of TOCA1, providing the first structural data for this protein. We have found that the TOCA1 HR1, like the closely related CIP4 HR1, has interesting structural features that are not observed in other HR1 domains. We have also investigated the binding of the TOCA HR1 domain to Cdc42 and the potential ternary complex between Cdc42 and the G protein-binding regions of TOCA1 and a member of the Wiskott-Aldrich syndrome protein family, N-WASP. TOCA1 binds Cdc42 with micromolar affinity, in contrast to the nanomolar affinity of the N-WASP G protein-binding region for Cdc42. NMR experiments show that the Cdc42-binding domain from N-WASP is able to displace TOCA1 HR1 from Cdc42, whereas the N-WASP domain but not the TOCA1 HR1 domain inhibits actin polymerization. This suggests that TOCA1 binding to Cdc42 is an early step in the Cdc42-dependent pathways that govern actin dynamics, and the differential binding affinities of the effectors facilitate a handover from TOCA1 to N-WASP, which can then drive recruitment of the actin-modifying machinery.JRW is supported by a Herchel Smith studentship. JLG is supported by a Wellcome Trust Research Career Development Fellowship (WT095829AIA), European Research Council Starting Grant (281971) and Gurdon Institute funding provided by the Wellcome Trust (092096) and CRUK (C6946/A14492). HMF is supported by a Wellcome Trust PhD Studentship (WT099740Z12Z). We would like to thank Dr A Walrant for help with the pyrene actin assays and liposome preparation. We are also grateful to Dr J.R. Peterson (Fox Chase Cancer Center) for human TOCA1 clones.This is the final version of the article. It first appeared from the American Society for Biochemistry and Molecular Biology via http://dx.doi.org/10.1074/jbc.M116.72429