75,125 research outputs found
The Benefits of Being Economics Professor A (and not Z)
No full textAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
Final word on Jersey Dutch
No full textIn this article, William Z. Shetter compares and contrasts the dialects that developed between different Dutch colonies in the New World. He explores in-depth the nuances of Jersey Dutch, and provides theories to explain how Dutch and colonial languages blended. The article is reprinted from American Speech, December 1958, Volum XXXIII, No. 4
Cocoa and cocoa bean shells role in human health: An updated review
No full textCocoa is derived from the seeds of Theobroma cacao L., an evergreen tree typical of tropical regions. It contains
numerous phytochemicals, with polyphenols representing the largest groups of compounds inside the seed, and
has been implicated in numerous biological properties, such as antioxidant, antiproliferative, antiapoptotic, antiinflammatory,
anti-cancer. Moreover, cocoa has been investigated in different health conditions, including heart
diseases, dyspepsia, nervous system diseases, circulation problems, and many others. Given its high consumption
in many countries all over the world, it is important to know and understand its effects on human health. In
addition, the cocoa bean shell, a by-product of the process of cocoa preparation, has been gaining remarkable
interest due to its high content of phytochemicals. This review summarizes the available literature and works on
the health benefits of cocoa and cocoa bean shells. Moreover, the current review focuses on studies investigating
their possible therapeutic roles in cancer and the underlining potential mechanisms of action
Microcephaly associated with a familial balanced translocation t(5;18)(q35.2;q22.3):gene expression studies in lymphoblastoid cell‐lines.
No full textBackground Autosomal dominant non‐syndromic microcephaly is a rare and heterogenous condition of unknown genetic etiology. However, chromosomal imbalances that have repeatedly been associated with microcephaly may offer a way to identify novel genes for non‐syndromic microcephaly. One such region is 5q35.2. Microdeletions in 5q35.2 including the gene NKX2.5 are associated to congenital heart defects and microcephaly. Since mutations in NKX2.5 are causal for congenital heart defects but are never associated with microcephaly, 5q35.2 deletions cause a contiguous gene deletion syndrome. Thus, in this chromosomal region a gene or regulatory element associated to dominant microcephaly is present. Methods We present a unique family where a balanced translocation t(5;18)(q35.2;q22.3) segregates with microcephaly in 4 out of 7 carriers. Fine mapping of the breakpoints was performed by use of 1 Mb BAC/PAC array Comparative Genome Hybridisation (array‐CGH), Fluorescent In Situ Hybridisation (FISH) and consecutive rounds of quantitative Real Time PCR (qRT‐PCR). Rigorous gene expression studies of all genes within a 4Mb region flanking the intergenic breakpoint on chromosome 5q35.2 were carried out on EBV‐transformed lymphoblastoid cell‐lines from 5 carriers by means of qRT‐PCR. Results Fine mapping of the breakpoints revealed that the breakpoint on chromosome 5q35.2 was located in an intergenic region previously associated with non‐syndromic microcephaly. Of the 27 genes in this region, only 11 revealed a reliably detectable expression pattern in these cells. However, in contrast to a positive control carrying a deletion in the region, for none of these genes, a significantly altered expression was observed. Conclusions The clinical and genetic findings support the observation that chromosome region 5q35.2 harbors a gene implicated in microcephaly, but also illustrate the limitations of the use of EBV‐transformed lymphoblastoid cell‐lines in expression studies of genes involved in brain growth.Autosomal dominant non‐syndromic microcephaly is a rare and heterogenous condition of unknown
genetic etiology. However, chromosomal imbalances that have repeatedly been associated with
microcephaly may offer a way to identify novel genes for non‐syndromic microcephaly. One such
region is 5q35.2. Microdeletions in 5q35.2 including the gene NKX2.5 are associated to congenital
heart defects and microcephaly. Since mutations in NKX2.5 are causal for congenital heart defects
but are never associated with microcephaly, 5q35.2 deletions cause a contiguous gene deletion
syndrome. Thus, in this chromosomal region a gene or regulatory element associated to dominant
microcephaly is present
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Statistics of the subgrid scales after the shock-turbulence interaction
No full textThe interaction of a normal shock with isotropic turbulence (IT) represents a basic problem for studying some of the phenomena associated with high speed flows, such as hypersonic flight, supersonic combustion and Inertial Confinement Fusion (ICF). In general, in practical applications, the shock width is much smaller than the turbulence scales and the upstream turbulent Mach number is modest. In this case, recent high resolution shock-resolved Direct Numerical Simulations (DNS) (Ryu and Livescu, J. Fluid Mech., 756, R1, 2014) show that the interaction can be described by the Linear Interaction Approximation (LIA). By using LIA to alleviate the need to solve the shock, DNS post-shock data can be generated at much higher Reynolds numbers than previously possible. Here, such results with Taylor Reynolds number around are used to investigate the properties of the subgrid scales (SGS). In particular, it is shown that the shock interaction decreases the asymmetry of the SGS dissipation PDF as the shock Mach number increases, with a significant enhancement in size of the regions and magnitude of backscatter
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
Triangular Constellations in Flows
No full textParticles advected on the surface of a fluid can exhibit fractal clustering. The local structure of a fractal set is described by its dimension , which is the exponent of a power-law relating the mass in a ball to its radius : . It is desirable to characterise the {\em shapes} of constellations of points sampling a fractal measure, as well as their masses. The simplest example is the distribution of shapes of triangles formed by triplets of points, which we investigate for fractals generated by chaotic dynamical systems. The most significant parameter describing the triangle shape is the ratio of its area to the radius of gyration squared. We show that the probability density of has a phase transition: is independent of and approximately uniform below a critical flow compressibility , which we estimate. For the distribution appears to be described by two power laws: when , and when
Preferential concentration of particles in compressible turbulence
No full textThe behavior of particles in compressible turbulence has been seldom investigated to date despite its importance in many natural and industrial flows. Direct numerical simulations of particle-laden compressible isotropic turbulence are performed to study the preferential concentration of particles and the underling mechanisms. It turns out that heavy particles tend to concentrate in regions of low enstrophy and high fluid density (i.e, strain regions between vortex rings), especially the particles of Kolmogorov scale, which show the largest number density. Due to the compressibility, fluid particles do not distribute uniformly as in incompressible case, but show a tendency to bunch up in high density zones. The preliminary result might give some insights into compressible turbulent transport, dispersion and mixing as well as the subgrid-scale modeling for large-eddy simulation of particle-laden compressible flows
Turbulent structures in unsteady wall-bounded flow subject to temporal acceleration
No full textDirect numerical simulations (DNS) of a transient turbulent channel flow subject to constant temporal acceleration have been performed with a final Reynolds number of \Retau=800. The response of turbulent structures to the temporal acceleration is investigated. A significant delay in the response of turbulent flow is observed in various turbulent properties. It is found that the response of turbulent flow to temporal acceleration consists of two stages: the destruction of the initial \emph{old} turbulence, followed by the generation of \emph{new} turbulence associated with a higher number. The \emph{new} turbulence is much stronger than the \emph{old} turbulence
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