An investigation into approximate solutions for deterministic and stochastic multi-dimensional sequencing

A description is given of an investigation in detail into the validity of the overlap integral method for describing planar optical waveguide junctions. A comparison between the results of this method and that of a rigorous mode-matching approach is taken

Wiretapping a hidden network

We consider the problem of maximizing the probability of hitting a strategically chosen hidden virtual network by placing a wiretap on a single link of a communication network. This can be seen as a two-player win-lose (zero-sum) game that we call the wiretap game. The value of this game is the greatest probability that the wiretapper can secure for hitting the virtual network. The value is shown to equal the reciprocal of the strength of the underlying graph. We efficiently compute a unique partition of the edges of the graph, called the prime-partition, and find the set of pure strategies of the hider that are best responses against every maxmin strategy of the wiretapper. Using these special pure strategies of the hider, which we call omni-connected-spanning-subgraphs, we define a partial order on the elements of the prime-partition. From the partial order, we obtain a linear number of simple two-variable inequalities that define the maxmin-polytope, and a characterization of its extreme points. Our definition of the partial order allows us to find all equilibrium strategies of the wiretapper that minimize the number of pure best responses of the hider. Among these strategies, we efficiently compute the unique strategy that maximizes the least punishment that the hider incurs for playing a pure strategy that is not a best response. Finally, we show that this unique strategy is the nucleolus of the recently studied simple cooperative spanning connectivity game

Relationship of serum prolactin with severity of drug use and treatment outcome in cocaine dependence.

RATIONALE: Alteration in serum prolactin (PRL) levels may reflect changes in central dopamine activity, which modulates the behavioral effects of cocaine. Therefore, serum PRL may have a potential role as a biological marker of drug severity and treatment outcome in cocaine dependence. OBJECTIVE: We investigated whether serum PRL levels differed between cocaine-dependent (CD) subjects and controls, and whether PRL levels were associated with severity of drug use and treatment outcome in CD subjects. METHODS: Basal PRL concentrations were assayed in 141 African-American (AA) CD patients attending an outpatient treatment program and 60 AA controls. Severity of drug use was assessed using the Addiction Severity Index (ASI). Measures of abstinence and retention during 12 weeks of treatment and at 6-month follow-up were employed as outcome variables. RESULTS: The basal PRL (ng/ml) in CD patients (9.28+/-4.13) was significantly higher than controls (7.33+/-2.94) (t=3.77, P\u3c0.01). At baseline, PRL was positively correlated with ASI-drug (r=0.38, P\u3c0.01), ASI-alcohol (r=0.19, P\u3c0.05), and ASI-psychological (r=0.25, P\u3c0.01) composite scores, and with the quantity of cocaine use (r=0.18, P\u3c0.05). However, PRL levels were not significantly associated with number of negative urine screens, days in treatment, number of sessions attended, dropout rate or changes in ASI scores during treatment and at follow-up. Also, basal PRL did not significantly contribute toward the variance in predicting any of the outcome measures. CONCLUSION: Although cocaine use seems to influence PRL levels, it does not appear that PRL is a predictor of treatment outcome in cocaine dependence

Microgravity’s Effect on the Virulence of Bacteriophage qB on Escherichia coli as a Possible Indicator of the Down-Regulation of Host Factor Hfq

Faculty Research Day 2018: Student Spaceflight Experiments Program FinalistFaculty Research Day 2018: Undergraduate Student Poster 2nd PlaceThe virulence of viruses is a topic of interest for the wellbeing of human health during space travel. Little research has been conducted on differing virulence between bacteriophages in space and on earth. However, prior research suggests evidence that a difference may exist. Hfq is an RNA binding global regulator protein present in E. coli which has been shown to be required for Coliphage qB to infect E. coli.  In a squid-vibrio experiment conducted under simulated microgravity, the hfq protein production was seen to be down-regulated in Vibrio fischeri. Our experiment aims to imitate results found by Grant under a real microgravity situation in Escherichia coli, given that Hfq is highly conserved in bacteria. The experiment will compare the virulence of Coliphage qB on E. coli in space to the virulence on land. The resulting difference in rates of Coliphage qB infection of E. coli may hint at unknown molecular mechanisms that bacteria and/or viruses employ under the effects of microgravity, and may provide evidence to suggest that hfq is also down-regulated in E. coli in microgravity. The implications of the results found by this experiment will be a step into determining the virulence of viruses and other infectious organisms during spaceflight and may lead to effective preventative measures to safeguard the health of humans in space

Medical symptoms associated with tobacco smoking with and without marijuana abuse among crack cocaine-dependent patients.

Despite the widespread use of tobacco and marijuana by cocaine abusers, it remains unclear whether combined tobacco and marijuana smoking is more harmful than tobacco smoking alone in cocaine abusers. We investigated the differences in medical symptoms reported among 34 crack cocaine abusers who did not smoke tobacco or marijuana (C), 86 crack cocaine abusers who also smoked tobacco (C + T), and 48 crack abusers who smoked both tobacco and marijuana (C + T + M). Medical symptoms were recorded using a 134-item self-report instrument (MILCOM), and drug use was assessed using the Addiction Severity Index (ASI). After controlling for clinical and demographic differences, the C + T + M group reported significantly more total symptoms on the MILCOM as well as on the respiratory, digestive, general, and nose/throat subscales than the C + T or C groups. The C + T group reported higher total and respiratory and nose/throat symptoms than the C group. HOwever, the C group had the highest number of mood symptoms among the three groups. The C + T and C + T + M groups were comparable in number of cigarettes smoked and ASI scores. Although tobacco smoking is associated with higher reports of medical problems in crack abusers, smoking both marijuana and tobacco seems to be associated with greater medical problems than smoking tobacco alone. Tobacco smoking was not related to changes in cocaine use. Also, marijuana smoking does not appear to be associated with a reduction in tobacco or cocaine use