1,494 research outputs found
The free and combined amino acid contents in species of Caulerpa from southeast coast of India
Caulerpa racemosa var. macrophysa, C. racemosa var cornyphora and C. scalpelliformis are analyzed by quantitative paper chromatographic technique for their amino acid contents in proteins, peptides and free state. It is found that no appreciable variation occurs in the quality of amino acid make up in these algae; but quantitative differences are apparent in them. Moreover, both qualitative and quantitative variations occur in the amino acid make up of the peptides, and in the free state. The results are compared with those of the other investigations
The protein, peptide and free amino-acid contents of some species of Gracilaria from south-east coast of India
Four species of Gracilaria are investigated for their free amino-acid contents, as well as amino-acid constituents in the proteins and the peptides, using quantitative paper chromatographic technique. Amino-acid constituents of different species of Gracilaria differ only in amount, while free amino-acids and the amino-acids in the peptides vary both in quality and quantity. A number of amino-acids recorded as protein constituents have even escaped detection in the peptides, while in the free state they occur either in all the species or in some only except homocystine. Moreover, some amino-acids occur exclusively in the free state
Hifâ1alpha stabilisation is protective against infection in zebrafish comorbid models
Multiâdrugâresistant tuberculosis is a worldwide problem, and there is an urgent need for hostâderived therapeutic targets, circumventing emerging drug resistance. We have previously shown that hypoxiaâinducible factorâ1α (Hifâ1α) stabilisation helps the host to clear mycobacterial infection via neutrophil activation. However, Hifâ1α stabilisation has also been implicated in chronic inflammatory diseases caused by prolonged neutrophilic inflammation. Comorbid infection and inflammation can be found together in disease settings, and it remains unclear whether Hifâ1α stabilisation would be beneficial in a holistic disease setting. Here, we set out to understand the effects of Hifâ1α on neutrophil behaviour in a comorbid setting by combining two wellâcharacterised in vivo zebrafish models â TB infection (Mycobacterium marinum infection) and sterile injury (tailfin transection). Using a local Mm infection near to the tailfin wound site caused neutrophil migration between the two sites that was reduced during Hifâ1α stabilisation. During systemic Mm infection, wounding leads to increased infection burden, but the protective effect of Hifâ1α stabilisation remains. Our data indicate that Hifâ1α stabilisation alters neutrophil migration dynamics between comorbid sites and that the protective effect of Hifâ1α against Mm is maintained in the presence of inflammation, highlighting its potential as a hostâderived target against TB infection
Searching for Signatures of Cosmic Superstrings in the CMB
Because cosmic superstrings generically form junctions and gauge theoretic
strings typically do not, junctions may provide a signature to distinguish
between cosmic superstrings and gauge theoretic cosmic strings. In cosmic
microwave background anisotropy maps, cosmic strings lead to distinctive line
discontinuities. String junctions lead to junctions in these line
discontinuities. In turn, edge detection algorithms such as the Canny algorithm
can be used to search for signatures of strings in anisotropy maps. We apply
the Canny algorithm to simulated maps which contain the effects of cosmic
strings with and without string junctions. The Canny algorithm produces edge
maps. To distinguish between edge maps from string simulations with and without
junctions, we examine the density distribution of edges and pixels crossed by
edges. We find that in string simulations without Gaussian noise (such as
produced by the dominant inflationary fluctuations) our analysis of the output
data from the Canny algorithm can clearly distinguish between simulations with
and without string junctions. In the presence of Gaussian noise at the level
expected from the current bounds on the contribution of cosmic strings to the
total power spectrum of density fluctuations, the distinction between models
with and without junctions is more difficult. However, by carefully analyzing
the data the models can still be differentiated.Comment: 15 page
Sub-clinical assessment of atopic dermatitis severity using angiographic optical coherence tomography
Measurement of sub-clinical atopic dermatitis (AD) is important for determining how long therapies should be continued after clinical clearance of visible AD lesions. An important biomarker of sub-clinical AD is epidermal hypertrophy, the structural measures of which often make optical coherence tomography (OCT) challenging due to the lack of a clearly delineated dermal-epidermal junction in AD patients. Alternatively, angiographic OCT measurements of vascular depth and morphology may represent a robust biomarker for quantifying the severity of clinical and sub-clinical AD. To investigate this, angiographic data sets were acquired from 32 patients with a range of AD severities. Deeper vascular layers within skin were found to correlate with increasing clinical severity. Furthermore, for AD patients exhibiting no clinical symptoms, the superficial plexus depth was found to be significantly deeper than healthy patients at both the elbow (p = 0.04) and knee (p < 0.001), suggesting that sub-clinical changes in severity can be detected. Furthermore, the morphology of vessels appeared altered in patients with severe AD, with significantly different vessel diameter, length, density and fractal dimension. These metrics provide valuable insight into the sub-clinical severity of the condition, allowing the effects of treatments to be monitored past the point of clinical remission
PAPPA: Primordial Anisotropy Polarization Pathfinder Array
The Primordial Anisotropy Polarization Pathfinder Array (PAPPA) is a
balloon-based instrument to measure the polarization of the cosmic microwave
background and search for the signal from gravity waves excited during an
inflationary epoch in the early universe. PAPPA will survey a 20 x 20 deg patch
at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212,
and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip
transmission line to combine the phase modulation techniques used in radio
astronomy with the sensitivity of transition-edge superconducting bolometers.
Each switched circuit modulates the incident polarization on a single detector,
allowing nearly instantaneous characterization of the Stokes I, Q, and U
parameters. We describe the instrument design and status.Comment: 12 pages, 9 figures. Proceedings of the Fundamental Physics With CMB
workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy
Review
Low Complexity Regularization of Linear Inverse Problems
Inverse problems and regularization theory is a central theme in contemporary
signal processing, where the goal is to reconstruct an unknown signal from
partial indirect, and possibly noisy, measurements of it. A now standard method
for recovering the unknown signal is to solve a convex optimization problem
that enforces some prior knowledge about its structure. This has proved
efficient in many problems routinely encountered in imaging sciences,
statistics and machine learning. This chapter delivers a review of recent
advances in the field where the regularization prior promotes solutions
conforming to some notion of simplicity/low-complexity. These priors encompass
as popular examples sparsity and group sparsity (to capture the compressibility
of natural signals and images), total variation and analysis sparsity (to
promote piecewise regularity), and low-rank (as natural extension of sparsity
to matrix-valued data). Our aim is to provide a unified treatment of all these
regularizations under a single umbrella, namely the theory of partial
smoothness. This framework is very general and accommodates all low-complexity
regularizers just mentioned, as well as many others. Partial smoothness turns
out to be the canonical way to encode low-dimensional models that can be linear
spaces or more general smooth manifolds. This review is intended to serve as a
one stop shop toward the understanding of the theoretical properties of the
so-regularized solutions. It covers a large spectrum including: (i) recovery
guarantees and stability to noise, both in terms of -stability and
model (manifold) identification; (ii) sensitivity analysis to perturbations of
the parameters involved (in particular the observations), with applications to
unbiased risk estimation ; (iii) convergence properties of the forward-backward
proximal splitting scheme, that is particularly well suited to solve the
corresponding large-scale regularized optimization problem
Gene expression time delays & Turing pattern formation systems
The incorporation of time delays can greatly affect the behaviour of partial differential equations and dynamical systems. In addition, there is evidence that time delays in gene expression due to transcription and translation play an important role in the dynamics of cellular systems. In this paper, we investigate the effects of incorporating gene expression time delays into a one-dimensional putative reaction diffusion pattern formation mechanism on both stationary domains and domains with spatially uniform exponential growth. While oscillatory behaviour is rare, we find that the time taken to initiate and stabilise patterns increases dramatically as the time delay is increased. In addition, we observe that on rapidly growing domains the time delay can induce a failure of the Turing instability which cannot be predicted by a naive linear analysis of the underlying equations about the homogeneous steady state. The dramatic lag in the induction of patterning, or even its complete absence on occasions, highlights the importance of considering explicit gene expression time delays in models for cellular reaction diffusion patterning
Out of sight and out of mind? A literature review of occupational safety and health leadership and management of distributed workers
Distributed workers â those who work autonomously and remotely from their organisationâs main locations for at least some of their work-time â are an important and growing proportion of the workforce that share common characteristics of temporal and spatial distance. Yet, many leadership styles and management practices assume face-to-face interaction, potentially rendering them less helpful in trying to ensure good occupational safety and health (OSH) outcomes for distributed workers. We conducted a systematic literature review to examine the leadership and management of OSH for distributed workers. Twenty-three papers were identified. Eleven papers identified established leadership styles, including leader-member exchange, (safety specific) transformational and considerate leadership. Twenty papers examined management. Findings from these 20 papers were interpreted as representing resources, deployed through management and utilised by managers to ensure OSH for distributed workers, including communication technologies, social support and a good safety climate. Despite limited research in this area, findings indicate the importance of both leadership and management in ensuring OSH for distributed workers. Findings suggest a fertile area for future enquiry
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