4,041 research outputs found
Gα16, a G Protein α Subunit Specifically Expressed in Hematopoietic Cells
Signal-transduction pathways mediated by guanine nucleotide-binding regulatory proteins (G proteins) determine many of the responses of hematopoietic cells. A recently identified gene encoding a G protein α subunit, Gα16, is specifically expressed in human cells of the hematopoietic lineage. The Gα16 cDNA encodes a protein with predicted Mr of 43,500, which resembles the Gq class of α subunits and does not include a pertussis toxin ADP-ribosylation site. In comparison with other G protein α subunits, the Gα16 predicted protein has distinctive amino acid sequences in the amino terminus, the region A guanine nucleotide-binding domain, and in the carboxyl-terminal third of the protein. Cell lines of myelomonocytic and T-cell phenotype express the Gα16 gene, but no expression is detectable in two B-cell lines or in nonhematopoietic cell lines. Gα16 gene expression is down-regulated in HL-60 cells induced to differentiate to neutrophils with dimethyl sulfoxide. Antisera generated from synthetic peptides that correspond to two regions of Gα16 specifically react with a protein of 42- to 43-kDa in bacterial strains that overexpress Gα16 and in HL-60 membranes. This protein is decreased in membranes from dimethyl sulfoxide-differentiated HL-60 cells and is not detectable in COS cell membranes. The restricted expression of this gene suggests that Gα16 regulates cell-type-specific signal-transduction pathways, which are not inhibited by pertussis toxin
Effective potentials and electrostatic interactions in self-assembled molecular bilayers II: the case of biological membranes
We propose a very simple but realistic enough model which allows to include a
large number of molecules in molecular dynamics MD simulations of these
bilayers, but nevertheless taking into account molecular charge distributions,
flexible amphiphilic molecules and a reliable model of water. All these
parameters are essential in a nanoscopic scale study of intermolecular and long
range electrostatic interactions. This model was previously used by us to
simulate a Newton black film and in this paper we extend our investigation to
bilayers of the biological membrane type. The electrostatic interactions are
calculated using Ewald sums and, for the macroscopic long range electrostatic
interactions, we use our previously proposed coarsed fit of the (perpendicular
to the bilayer plane) molecular charge distributions with gaussian
distributions. To study an unique biological membrane (not an stack of
bilayers), we propose a simple effective external potential that takes into
account the microscopic pair distribution functions of water and is used to
simulate the interaction with the surrounding water. The method of effective
macroscopic and external potentials is extremely simple to implement in
numerical simulations, and the spatial and temporal charge inhomogeneities are
then roughly taken into account. Molecular dynamics simulations of several
models of a single biological membrane, of neutral or charged polar
amphiphilics, with or without water (using the TIP5P intermolecular potential
for water) are included
Human response to vibration in residential environments (NANR209), executive summary
The aim of the Defra-funded project NANR209 âHuman response to vibration in residential environmentsâ was to develop exposure-response relationships for vibration experienced in residential environments from sources outside of the residentsâ control. The project was performed at the University of Salford between January 2008 and March 2011. The final report was published on the Defra website on 6th September 2012.
The NANR209 Final Report consists of the following documents:
âą Executive summary
âą Final project report
âą Technical report 1: Measurement of vibration exposure
âą Technical report 2: Measurement of response
âą Technical report 3: Calculation of vibration exposure
âą Technical report 4: Measurement and calculation of noise exposure
âą Technical report 5: Analysis of the social survey findings
âą Technical report 6: Determination of exposure-response relationships
This document is the Executive summary
Level-Based Analysis of the Population-Based Incremental Learning Algorithm
The Population-Based Incremental Learning (PBIL) algorithm uses a convex
combination of the current model and the empirical model to construct the next
model, which is then sampled to generate offspring. The Univariate Marginal
Distribution Algorithm (UMDA) is a special case of the PBIL, where the current
model is ignored. Dang and Lehre (GECCO 2015) showed that UMDA can optimise
LeadingOnes efficiently. The question still remained open if the PBIL performs
equally well. Here, by applying the level-based theorem in addition to
Dvoretzky--Kiefer--Wolfowitz inequality, we show that the PBIL optimises
function LeadingOnes in expected time for a population size , which matches the bound
of the UMDA. Finally, we show that the result carries over to BinVal, giving
the fist runtime result for the PBIL on the BinVal problem.Comment: To appea
Human response to vibration in residential environments (NANR209), Technical report 6 : determination of exposure-response relationships
This technical report presents the development of exposure-response relationships for the human response to vibration in residential environments. The data used to formulate the relationships presented in this report are those which were collected for the Defra funded project âNANR209: Human response to vibration in residential environmentsâ, the main aim of which was the development of exposure-response relationships. Vibration caused by railway traffic, construction work, and internal sources outside of the residentsâ control were considered. Response data was collected via face to face interviews with residents in their own homes. The questionnaire was presented as a neighbourhood satisfaction survey and gathered information on, among other things, annoyance caused by vibration and noise exposure. Development and implementation of the questionnaire used for the collection of response data is discussed in Technical Report 2 and Technical Report 5. Vibration exposure was determined via measurement and prediction in such a way that, where possible, an estimation of internal vibration exposure was established for each residence in which a questionnaire was completed. The measurement procedures and methods employed to estimate vibration exposure are detailed in Technical Report 1 and Technical Report 3. Estimations of noise exposure were also derived for each residence using the methods detailed in Technical Report 4
Using local experts as benchmarks for household local ecological knowledge: scoring in South African savannas
It is well recognised that local ecological knowledge is an important facet of natural resource management in rural regions of the developing world. However, techniques to assess levels and to integrate it into formal or informal management approaches require further development. In particular, quantitative tools are missing, which would allow more robust analysis of the factors that positively or negatively affect local ecological knowledge and vice versa. This paper reports on a quick assessment approach that provides a quantitative score of generalist local ecological knowledge at the household level. It does so by comparing responses to the knowledge of local people identified as experts within the community. In this way it is both locally constructed and contextualized, and thereby avoids pitfalls of trying to score local ecological knowledge relative to conventional scientific knowledge which frequently cannot account for local constructs. The approach is applied at eight villages throughout the savanna biome in South Africa
From Physical to Cyber: Escalating Protection for Personalized Auto Insurance
Nowadays, auto insurance companies set personalized insurance rate based on
data gathered directly from their customers' cars. In this paper, we show such
a personalized insurance mechanism -- wildly adopted by many auto insurance
companies -- is vulnerable to exploit. In particular, we demonstrate that an
adversary can leverage off-the-shelf hardware to manipulate the data to the
device that collects drivers' habits for insurance rate customization and
obtain a fraudulent insurance discount. In response to this type of attack, we
also propose a defense mechanism that escalates the protection for insurers'
data collection. The main idea of this mechanism is to augment the insurer's
data collection device with the ability to gather unforgeable data acquired
from the physical world, and then leverage these data to identify manipulated
data points. Our defense mechanism leveraged a statistical model built on
unmanipulated data and is robust to manipulation methods that are not foreseen
previously. We have implemented this defense mechanism as a proof-of-concept
prototype and tested its effectiveness in the real world. Our evaluation shows
that our defense mechanism exhibits a false positive rate of 0.032 and a false
negative rate of 0.013.Comment: Appeared in Sensys 201
Advances in startercultures and cultured foods
With 2005 retail sales close to $4.8 million, cultured dairy products are driving the growth of dairy foods consumption. Starter cultures are of great industrial significance in that they play a vital role in the manufacturing, flavor, and texture development of fermented dairy foods. Furthermore, additional interest in starter bacteria has been generated because of the data accumulating on the potential health benefits of these organisms. Today, starter cultures for fermented foods are developed mainly by design rather than by the traditional screening methods and trial and error. Advances in genetics and molecular biology have provided opportunities for genomic studies of these economically significant organisms and engineering of cultures that focuses on rational improvement of the industrially useful strain. Furthermore, much research has been published on the health benefits associated with ingesting cultured dairy foods and probiotics, particularly their role in modulating immune function. The aim of this review is to describe some of the major scientific advances made in starter and non-starter lactic acid bacteria during the past 10 yr, including genomic studies on dairy starter cultures, engineering of culture attributes, advances in phage control, developments in methods to enumerate lactic acid bacteria and probiotics in dairy foods, and the potential role of cultured dairy foods in modulation of immune function
Phase transitions on the surface of a carbon nanotube
A suspended carbon nanotube can act as a nanoscale resonator with remarkable
electromechanical properties and the ability to detect adsorption on its
surface at the level of single atoms. Understanding adsorption on nanotubes and
other graphitic materials is key to many sensing and storage applications. Here
we show that nanotube resonators offer a powerful new means of investigating
fundamental aspects of adsorption on carbon, including the collective behaviour
of adsorbed matter and its coupling to the substrate electrons. By monitoring
the vibrational resonance frequency in the presence of noble gases, we observe
the formation of monolayers on the cylindrical surface and phase transitions
within these monolayers, and simultaneous modification of the electrical
conductance. The monolayer observations also demonstrate the possibility of
studying the fundamental behaviour of matter in cylindrical geometry.Comment: Unpublished; 7 pages with 4 figures plus 3 pages of supplementary
materia
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