3,338 research outputs found
Estimation of Parameters in DNA Mixture Analysis
In Cowell et al. (2007), a Bayesian network for analysis of mixed traces of
DNA was presented using gamma distributions for modelling peak sizes in the
electropherogram. It was demonstrated that the analysis was sensitive to the
choice of a variance factor and hence this should be adapted to any new trace
analysed. In the present paper we discuss how the variance parameter can be
estimated by maximum likelihood to achieve this. The unknown proportions of DNA
from each contributor can similarly be estimated by maximum likelihood jointly
with the variance parameter. Furthermore we discuss how to incorporate prior
knowledge about the parameters in a Bayesian analysis. The proposed estimation
methods are illustrated through a few examples of applications for calculating
evidential value in casework and for mixture deconvolution
Biosynthesis of intestinal microvillar proteins Rapid expression of cytoskeletal components in microvilli of pig small intestinal mucosal explants
AbstractUsing alkaline extraction to separate cytoskeletal and membrane proteins of intestinal microvilli, the kinetics of assembly of these two microvillar protein compartments was studied by pulse-chase labelling of pig small intestinal mucosal explants, kept in organ culture. Following a 10 min pulse of [35S]methionine, the membrane proteins did not appear in the microvillar fraction until after 40â60 min of chase. In contrast, the cytoskeletal components, of which the 110-kDa protein and villin were immunologically identified, were expressed in the microvillar fraction immediately after the 10 min pulse. These different kinetics of appearance indicate that the two microvillar protein compartments have separate mechanisms of biosynthesis and microvillar expression
Urban wind power and the private sector : community benefits, social acceptance and public engagement
Given the ambitious government targets for renewable energy generation in the UK, there has been a push by government and industry towards various types and scales of Renewable Energy Technologies (RETs). This paper explores the implications of commercial urban wind projects for local communities, drawing on a case study of proposals by ASDA to construct wind turbines in two semi-urban locations in the UK. The paper argues that community responses to the proposals were complex and varied and could not adequately be encapsulated by 'nimby' (not in my back yard) assignations. It concludes that while ASDA followed a process of consulting local people, this process highlighted the problems of the 'business as usual' approach to public engagement employed by ASDA, and assumptions made about public acceptance of RETs
Gaussian Belief with dynamic data and in dynamic network
In this paper we analyse Belief Propagation over a Gaussian model in a
dynamic environment. Recently, this has been proposed as a method to average
local measurement values by a distributed protocol ("Consensus Propagation",
Moallemi & Van Roy, 2006), where the average is available for read-out at every
single node. In the case that the underlying network is constant but the values
to be averaged fluctuate ("dynamic data"), convergence and accuracy are
determined by the spectral properties of an associated Ruelle-Perron-Frobenius
operator. For Gaussian models on Erdos-Renyi graphs, numerical computation
points to a spectral gap remaining in the large-size limit, implying
exceptionally good scalability. In a model where the underlying network also
fluctuates ("dynamic network"), averaging is more effective than in the dynamic
data case. Altogether, this implies very good performance of these methods in
very large systems, and opens a new field of statistical physics of large (and
dynamic) information systems.Comment: 5 pages, 7 figure
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Spectrophotometric analysis of ternary uranyl systems to replace tri-N-butyl phosphate (TBP) in used fuel reprocessing
In this report, the interaction of monoamide/diamide and monoamide/diglycolamide mixtures with UO2+2 are investigated in pH = 1 methanolic nitric acid media. These monoamides include N,N-dimethylacetamide (DMAA), N,N-diethylacetamide (DEAA), N,N-dibutylacetamide (DBAA) and N,N-dibutylbutanamide (DBBA). N,N,Nâ˛Nâ˛-tetraethylmalonamide (TEMA) and N,N,Nâ˛,Nâ˛-tetraethyldiglycolamide (TEDGA), which were chosen as model diamides and diglycolamides, respectively. Complex stability constants for each ligand were modelled using the Stability Quotients Using Absorbance Data program using UVâvisible data. Complex stoichiometry of ligand mixtures was determined using Job plots and UVâVis spectrometry. Monoamides were confirmed to produce only disolvate complexes with UO2+2 in solution. The log10(K) values for monoamides were found to be independent of amine-side chain length, but were slightly dependent on the carbonyl-side chain length. TEDGA was found to produce multiple uranyl complexes in solution. Job plot data indicated that the uranyl cation strongly prefers to bond either only with the monoamide or diamide in ternary monoamideâdiamideâUO2 systems. MonoamideâdiglycolamideâUO2 systems were more complicated, with Job plot data indicating the potential for multiple ternary species being present is dependent on the monoamide structure
The neurodevelopment of social preferences in early childhood
Human social preferences are the product of gene-culture coevolution, and rely on predispositions that emerge early in development. These social preferences encompasse distinct motivations, mechanisms, and behaviors, that facilitate social cohesion and cooperation. Developmental social neuroscience critically contributes in elucidating the proximate mechanisms involved in social decision-making and prosociality, and their gradual maturation in interaction with the social and cultural environment
Origin of Enantioselection in Chiral Alcohol Oxidation Catalyzed by Pd[(-)-sparteine]Cl2
A kinetic investigation into the origin of enantioselectivity for the Pd[(-)-sparteine]Cl2-catalyzed aerobic oxidative kinetic resolution (OKR) is reported. A mechanism to account for a newly discovered chloride dissociation from Pd[(-)-sparteine]Cl2 prior to alcohol binding is proposed. The mechanism includes (1) chloride dissociation from Pd[(-)-sparteine]Cl2 to form cationic Pd(-)-sparteine]Cl, (2) alcohol binding, (3) deprotonation of Pd-bound alcohol to form a Pd-alkoxide, and (4) â-hydride elimination of Pd-alkoxide to form ketone product and a Pd-hydride. Utilizing the addition of (-)-sparteine HCl to control the [Cl-] and [H+] and the resulting derived rate law, the key microscopic kinetic and thermodynamic constants were extracted for each enantiomer of sec-phenethyl alcohol. These constants allow for the successful simulation of the oxidation rate in the presence of exogenous (-)-sparteine HCl. A rate law for oxidation of the racemic alcohol was derived that allows for the successful prediction of the experimentally measured krel values when using the extracted constants. Besides a factor of 10 difference between the relative rates of â-hydride elimination for the enantiomers, the main enhancement in enantiodetermination results from a concentration effect of (-)-sparteine HCl and the relative rates of reprotonation of the diastereomeric Pd-alkoxides
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