A cluster expansion approach to exponential random graph models

The exponential family of random graphs is among the most widely-studied network models. We show that any exponential random graph model may alternatively be viewed as a lattice gas model with a finite Banach space norm. The system may then be treated by cluster expansion methods from statistical mechanics. In particular, we derive a convergent power series expansion for the limiting free energy in the case of small parameters. Since the free energy is the generating function for the expectations of other random variables, this characterizes the structure and behavior of the limiting network in this parameter region.Comment: 15 pages, 1 figur

The hydroxy fatty acids: Isolation, structure determination, quantitation

This review and commentary on quantitative methodology of the hydroxy fatty acids covers methods of isolation, structure determination, and quantitative analysis. Individual topics are: methods of liberation from bound form, separation by partition, separation by partition columns, separation by precipitation, separation by adsorption columns, separation by thin‐layer chromatography, separation of homologous fatty acids, locating the hydroxyl group, characterization of the optically active hydroxyl group, locating the double bonds, gravimetric determination, colorimetric determination, gas chromatographic determination, infrared absorption, titrimetric determination, and radiometric determination.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141899/1/aocs0569.pd

Killing cancer cells by poly-drug elevation of ceramide levels

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66186/1/j.1432-1033.2001.01845.x.pd

Drug design: hiding in full view

Compounds that can produce potent biological effects in cells encompass a variety of structural motifs. Many of these compounds share a structural feature that has rarely been noted. It is an allylic cluster of atoms, a 3-carbon chain with a double bond between two of the atoms and an oxygen atom at the other end. The oxygen can be in a hydroxyl group, or in an ether or ketal or ester linkage, or simply a carbonyl form. In the latter case, the linkage is an allylic ketone (ene-one) structure. Nitrogen is often seen in equivalent forms. Inclusion of at least one allylic moiety appears to be able to turn a modestly active or inert compound into an effective drug or toxin. Some compounds lack the allylic moiety but develop one by enzymatic action, usually via cytochrome P-450 enzymes. These metabolites probably represent the active drug forms. The above concepts seem to be radically simplistic and improbable, but the evidence supporting them and the explanations for the biological activities are hidden “in plain view.” Comparisons with the pleiotropic activities of the allylic sphingolipid, ceramide, indicate that many allylic drugs operate by controlling the state of protein phosphorylation, by activating proteases, by generating reactive oxygen species, by slowing mitochondrial electron transport, or by lowering cellular glutathione concentrations. Drug Dev Res 69:15–25, 2008 © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58639/1/20223_ftp.pd

Preparation of psychosines (1‐O‐hexosyl sphingosine) from cerebrosides

A convenient method for large or small scale preparation of psychosine from cerebroside has been developed by adaptation of published procedures. Cerebroside is refluxed with butanol and aqueous KOH, then the KOH is removed with perchloric acid. The fatty acids are removed by extraction with hexane and the excess perchloric acid is removed by partitioning between chloroform, ethanol, and water.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142232/1/lipd0358.pd

Impact of the effect of economic crisis and the targeted motorcycle safety programme on motorcycle-related accidents, injuries and fatalities in Malaysia

In 1997, a Motorcycle Safety Programme (MSP) was introduced to address the motorcycle-related accident problem. The MSP was specifically targeted at motorcyclists. In addition to the MSP, the recent economic recession has significantly contributed to a reduction of traffic-related incidents. This paper examines the effects of the recent economic crisis and the MSP on motorcycle-related accidents, casualties and fatalities in Malaysia. The autocorrelation integrated moving average model with transfer function was used to evaluate the overall effects of the interventions. The variables used in developing the model were gross domestic product and MSPs. The analysis found a 25% reduction in the number of motorcycle-related accidents, a 27% reduction in motorcycle casualties and a 38% reduction in motorcycle fatalities after the implementation of MSP. Findings indicate that the MSP has been one of the effective measures in reducing motorcycle safety problems in Malaysia. Apart from that, the performance of the country's economy was also found to be significant in explaining the number of motorcycle-related accidents, casualties and fatalities in Malaysia