Galaxy Zoo: A correlation between coherence of galaxy spin chirality and star formation efficiency

We report on the finding of a correlation between galaxies' past star formation activity and the degree to which neighbouring galaxies rotation axes are aligned. This is obtained by cross-correlating star formation histories, derived with MOPED, and spin direction (chirality), as determined by the Galaxy Zoo project, for a sample of SDSS galaxies. Our findings suggest that spiral galaxies which formed the majority of their stars early (z > 2) tend to display coherent rotation over scales of ~10 Mpc/h. The correlation is weaker for galaxies with significant recent star formation. We find evidence for this alignment at more than the 5-sigma level, but no correlation with other galaxy stellar properties. This finding can be explained within the context of hierarchical tidal-torque theory if the SDSS galaxies harboring the majority of the old stellar population where formed in the past, in the same filament and at about the same time. Galaxies with significant recent star formation instead are in the field, thus influenced by the general tidal field that will align them in random directions or had a recent merger which would promote star formation, but deviate the spin direction.Comment: matches published version in MNRAS; only minor change

Jet stream position explains regional anomalies in European beech forest productivity and tree growth.

The mechanistic pathways connecting ocean-atmosphere variability and terrestrial productivity are well-established theoretically, but remain challenging to quantify empirically. Such quantification will greatly improve the assessment and prediction of changes in terrestrial carbon sequestration in response to dynamically induced climatic extremes. The jet stream latitude (JSL) over the North Atlantic-European domain provides a synthetic and robust physical framework that integrates climate variability not accounted for by atmospheric circulation patterns alone. Surface climate impacts of north-south summer JSL displacements are not uniform across Europe, but rather create a northwestern-southeastern dipole in forest productivity and radial-growth anomalies. Summer JSL variability over the eastern North Atlantic-European domain (5-40E) exerts the strongest impact on European beech, inducing anomalies of up to 30% in modelled gross primary productivity and 50% in radial tree growth. The net effects of JSL movements on terrestrial carbon fluxes depend on forest density, carbon stocks, and productivity imbalances across biogeographic regions

Acoustic Forward Model for Guided Wave Propagation and Scattering in a Pipe Bend

The sections of pipe bends are hot spots for wall thinning due to accelerated corrosion by fluid flow. Conventionally, the thickness of a bend wall is evaluated by local point-by-point ultrasonic measurement, which is slow and costly. Guided wave tomography is an attractive method that enables the monitoring of a whole bend area by processing the waves excited and received by transducer arrays. The main challenge associated with the tomography of the bend is the development of an appropriate forward model, which should simply and efficiently handle the wave propagation in a complex bend model. In this study, we developed a two-dimensional (2D) acoustic forward model to replace the complex three-dimensional (3D) bend domain with a rectangular domain that is made artificially anisotropic by using Thomsen parameters. Thomsen parameters allow the consideration of the directional dependence of the velocity of the wave in the model. Good agreement was found between predictions and experiments performed on a 220 mm diameter (d) pipe with 1.5d bend radius, including the wave-field focusing effect and the steering effect of scattered wave-fields from defects

High-voltage diffusion-welded stacks on the basis of SiC Schottky diodes

Abstract. In the present work we have considered the prototype of a high-voltage diode stack made on the basis of commercial SiC Schottky diodes. Implementation of vertical integration for four diode chips yielded a stack with a reverse current of 25 µA under a reverse voltage of 6 kV. The capacitance of the stack at zero bias was reduced more than three-fold in comparison with the initial diodes. The reverse recovery time of the stack was 7.4 ns. This paper proposes a convenient analytical approach to the estimation of parameters of modular compositions with vertical architecture

Methods for Detection of Bioimpedance Variations in Resource Constrained Environments

Changes in a certain parameter are often a few magnitudes smaller than the base value of the parameter, specifying significant requirements for the dynamic range and noise levels of the measurement system. In case of electrical bioimpedance acquisition, the variations can be 1000 times smaller than the entire measured value. Synchronous or lock-in measurement of these variations is discussed in the current paper, and novel measurement solutions are presented. Proposed methods are simple and robust when compared to other applicable solutions. A common feature shared by all members of the group of the proposed solutions is differentiation. It is achieved by calculating the differences between synchronously acquired consecutive samples, with lock-in integration and analog differentiation. All these methods enable inherent separation of variations from the static component of the signal. The variable component of the bioimpedance can, thus, be acquired using the full available dynamic range of the apparatus for its detection. Additive disturbing signals and omnipresent wideband noise are considered and the method for their reduction is proposed

Intrachromosomal amplification of chromosome 21 (iAMP21) detected by ETV6/RUNX1 FISH screening in childhood acute lymphoblastic leukemia: a case report

Chromosome abnormalities that usually define high-risk acute lymphoblastic leukemia are the t(9;22)/ breakpoint cluster region protein-Abelson murine leukemia viral oncogene homolog 1, hypodiploid with < 44 chromosomes and 11q23/ myeloid/lymphoid leukemia gene rearrangements. The spectrum of acute lymphoblastic leukemia genetic abnormalities is nevertheless rapidly expanding. Therefore, newly described chromosomal aberrations are likely to have an impact on clinical care in the near future. Recently, the rare intrachromosomal amplification of chromosome 21 started to be considered a high-risk chromosomal abnormality. It occurs in approximately 2-5% of pediatric patients with B-cell precursor acute lymphoblastic leukemia. This abnormality is associated with a poor outcome. Hence, an accurate detection of this abnormality is expected to become very important in the choice of appropriate therapy. In this work the clinical and molecular cytogenetic evaluation by fluorescence in situ hybridization of a child with B-cell precursor acute lymphoblastic leukemia presenting the rare intrachromosomal amplification of chromosome 21 is described