Attitudes of Israeli Muslims at risk of genetic disorders towards pregnancy termination

OBJECTIVES: (1) To examine attitudes towards termination of pregnancy (TOP) among high-risk and non-high-risk (for cystic fibrosis) Arab-Muslims, and (2) to examine the effect of an intervention, which among other things related explicitly to TOP. METHODS: The study comprised three groups: (1) an intervention group at high risk for CF, which received community genetic counseling; (2) a control group at high risk for CF, and (3) a control group from the general population. The latter two groups were exposed to minimal intervention. Attitudes were measured two or three times during a 1-year period (for the control and intervention groups, respectively). RESULTS: Predictors of an affected fetus being considered a legitimate cause for TOP were religiosity, familiarity with an affected child, and benefits of the test. Predictors of individuals (hypothetically) choosing abortion in the case of an affected fetus were education and age. No change occurred in the attitudes of participants (either experimental or control groups) in the course of 1 year. CONCLUSIONS: Other possible intervention options are discussed, and specifically, the advantages of using opinion leaders such as clergy and medical staff.     

Bounds for algebraic gossip on graphs

We study the stopping times of gossip algorithms for network coding. We analyze algebraic gossip (i.e., random linear coding) and consider three gossip algorithms for information spreading: Pull, Push, and Exchange. The stopping time of algebraic gossip is known to be linear for the complete graph, but the question of determining a tight upper bound or lower bounds for general graphs is still open. We take a major step in solving this question, and prove that algebraic gossip on any graph of size n is O(Δn) where Δ is the maximum degree of the graph. This leads to a tight bound of for bounded degree graphs and an upper bound of O(n²) for general graphs. We show that the latter bound is tight by providing an example of a graph with a stopping time of . Our proofs use a novel method that relies on Jackson's queuing theorem to analyze the stopping time of network coding; this technique is likely to become useful for future research. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 45, 185–217, 2014     

Surface-enhanced Raman scattering detection of cholinesterase inhibitors

A new sensitive surface-enhanced Raman scattering (SERS) assay for detection of cholinesterase inhibitors such as organophosphorous pesticides using silver colloidal nanoparticles was developed and optimized. Acetylcholinesterase (AChE) mediated the hydrolysis of acetylthiocholine to produce thiocholine, which interacted with the silver nanoparticles to give a specific SERS spectrum. Variation in enzyme activity due to inhibition was measured from changes in intensity of a characteristic peak (772 cm⁻¹) of the SERS spectrum that was directly correlated with the concentration of produced thiocholine. The method was demonstrated for the detection of paraoxon as reference AChE inhibitor. Limit of detection of paraoxon for 5 min incubation at 25 °C was 1.8 × 10⁻⁸ M. This assay can be utilized for the detection of trace amounts of any AChE inhibitor.     

Algebraic signatures of convex and non-convex codes

A convex code is a binary code generated by the pattern of intersections of a collection of open convex sets in some Euclidean space. Convex codes are relevant to neuroscience as they arise from the activity of neurons that have convex receptive fields. In this paper, we develop algebraic methods to determine if a code is convex. Specifically, we use the neural ideal of a code, which is a generalization of the Stanley–Reisner ideal. Using the neural ideal together with its standard generating set, the canonical form, we provide algebraic signatures of certain families of codes that are non-convex. We connect these signatures to the precise conditions on the arrangement of sets that prevent the codes from being convex. Finally, we also provide algebraic signatures for some families of codes that are convex, including the class of intersection-complete codes. These results allow us to detect convexity and non-convexity in a variety of situations, and point to some interesting open questions.     

Numerical Simulation of a DC-Glow-Discharge in an Electronegative Gas

A one-dimensional continuum model is presented for a dc-glow-discharge in an electronegative gas between parallel plates. It is based on the local balance equations for particle densities and fluxes of electrons, positive and negative ions, the local electron energy balance and the Poisson equation for the self-consistent electric field. These equations are supplemented by suitably chosen boundary conditions and are solved by the finite difference procedure HEMODES (HEnyey Method Ordinary Differential Equation Solver) which, in particular, can successfully handle the singular point occuring if the inertia term in the ion momentum balance equation is taken into account. Since not all data needed within this treatment for the simulation of realistic electronegative gases were available, a fictitious argon-like gas has been considered which nevertheless can demonstrate the characteristic features of such a discharge. In particular, the influence of variations of the attachment and the ion-ion recombination coefficients on the physical variables has been studied.     

An EOQ Model with Substitutions Between Products

In this paper, we present an economic order quantity (EOQ) model when two products are required, and one can be substituted for the other, if necessary, at a given unit cost. We consider three cases: (i) when there is no substitution between the products, (ii) when there is full substitution between the products, and (iii) when there is partial substitution between the products. In a deterministic setting with proportional substitution costs, we would expect to find full substitution or no substitution being optimal, depending on the cost parameters. However, we observe that full substitution is never optimal; only partial substitution or no substitution may be optimal. This result can best be explained due to the non-linearity of the decision variables in the total cost expression. Finally, we present an algorithm to compute the optimal order quantities.     

Asymptotic behavior of the Weber location problem on the plane

The asymptotic behavior of the Weber location problem is investigated. We consider problems wheren demand points are randomly generated in a unit disk by a uniform distribution and all weights are equal to one. The main result of the paper is that the probability that the optimal solution be on a demand point is approximately 1/n. Additional results for a largen: the optimal solution converges almost surely to the center of the disk; the difference between the optimal value of the objective function and the minimal value of the objective function on a demand point converges to 1/2.     

A New Heuristic for the Quadratic Assignment Problem

We propose a new heuristic for the solution of the quadratic assignment problem. The heuristic combines ideas from tabu search and genetic algorithms. Run times are very short compared with other heuristic procedures. The heuristic performed very well on a set of test problems.