On the ground states of the Bernasconi model

The ground states of the Bernasconi model are binary +1/-1 sequences of length N with low autocorrelations. We introduce the notion of perfect sequences, binary sequences with one-valued off-peak correlations of minimum amount. If they exist, they are ground states. Using results from the mathematical theory of cyclic difference sets, we specify all values of N for which perfect sequences do exist and how to construct them. For other values of N, we investigate almost perfect sequences, i.e. sequences with two-valued off-peak correlations of minimum amount. Numerical and analytical results support the conjecture that almost perfect sequences do exist for all values of N, but that they are not always ground states. We present a construction for low-energy configurations that works if N is the product of two odd primes.Comment: 12 pages, LaTeX2e; extended content, added references; submitted to J.Phys.

A new material based on montmorillonite and Cu(II)-phenanthroline complex for effective capture of ammonia from gas phase

The intercalation of [Cu(Phen)(H2O)2]2+ (CuPhen) in montmorillonite (Mt) produces a stable hybrid material that is very efficient in removing NH3 from gas phase even at extremely low pressures. The process was studied by elemental analysis, X-ray powder diffraction, thermal analysis coupled with evolved gas mass spectrometry and DR UV–Vis, NMR and X-ray absorption spectroscopy. The adsorption of CuPhen on Mt consists of two consecutive steps. During the first one, CuPhen intercalates alone into Mt through a cation exchange process, afterwards CuPhen and SO42− ions entry jointly into the mineral interlayer. The two-steps adsorption process is described by a VI-type isotherm, successfully fitted by two independent Frumkin isotherms. NH3 trapping is long-lasting, easy, fast even at extremely low gas pressure and reversible under mild conditions. Mt containing CuPhen always results well performant in removing ammonia from gas phase, but an appreciably higher adsorption capacity of NH3 is obtained when SO42− ion is absent from the interlayer. This hybrid montmorillonite is thus a promising material to be used in industrial or environmental contexts, as an efficient air-cleaner

The efficacy of social role models to increase motivation to obtain vaccination against hepatitis B among men who have sex with men

This study assessed the effects of role models in persuasive messages about risk and social norms to increase motivation to obtain hepatitis B virus (HBV) vaccination in men who have sex with men (MSM). MSM at risk for HBV in The Netherlands (N = 168) were recruited online via a range of websites and were randomly assigned to one of four conditions in a 2 (risk communication: yes and no) × 2 (social norms communication: yes and no) factorial design. In each condition, participants subsequently provided self-completed assessments of their perceived risk of HBV infection, perceived social norms regarding HBV vaccination and their intention to obtain vaccination against HBV. Risk communication and social norms communication that used social role models were effective in significantly increasing men's intention to obtain vaccination against HBV. No additive effect was found for a combined message. Mediation analyses showed that communications influenced intention via perceived risk and social norms. Findings extend previous theorizing and research and show that both role model-based risk communication and social norms communication can be effective in increasing intentions to obtain HBV vaccination in MSM. This knowledge contributes to the development of effective health promotion to increase HBV vaccination in MSM. © The Author 2010

Design, synthesis and antiparasitic evaluation of click phospholipids

A library of seventeen novel ether phospholipid analogues, containing 5-membered heterocyclic rings (1,2,3-triazolyl, isoxazolyl, 1,3,4-oxadiazolyl and 1,2,4-oxadiazolyl) in the lipid portion were designed and synthesized aiming to identify optimised miltefosine analogues. The compounds were evaluated for their in vitro antiparasitic activity against Leishmania infantum and Leishmania donovani intracellular amastigotes, against Trypanosoma brucei brucei and against different developmental stages of Trypanosoma cruzi. The nature of the substituents of the heterocyclic ring (tail) and the oligomethylene spacer between the head group and the heterocyclic ring was found to affect the activity and toxicity of these compounds leading to a significantly improved understanding of their structure\u2013activity relationships. The early ADMET profile of the new derivatives did not reveal major liabilities for the potent compounds. The 1,2,3-triazole derivative 27 substituted by a decyl tail, an undecyl spacer and a choline head group exhibited broad spectrum antiparasitic activity. It possessed low micromolar activity against the intracellular amastigotes of two L. infantum strains and T. cruzi Y strain epimastigotes, intracellular amastigotes and trypomastigotes, while its cytotoxicity concentration (CC50) against THP-1 macrophages ranged between 50 and 100 \ub5M. Altogether, our work paves the way for the development of improved ether phospholipid derivatives to control neglected tropical diseases

Do brief motivational interventions reduce drinking game frequency in mandated students? An analysis of data from two randomized controlled trials.

PURPOSE: College students frequently engage in drinking games (DG) and experience a variety of consequences as a result. It is currently unknown whether brief motivational interventions (BMI) that provide feedback on DG participation can reduce this high risk behavior. This study examined outcome data from two randomized clinical trials to examine whether BMIs facilitate change in DG frequency and how these changes may occur. METHODS: Mandated college students (Trial 1, N = 198, 46% female; Trial 2, N = 412; 32% female) were randomized to BMI or comparison control conditions. Hierarchical linear modeling (HLM) was used to compare the BMI and comparison groups to determine whether the BMI reduced DG participation over time. Percent change talk (PCT) during the discussion of DG during the session was examined as a predictor of change in DG frequency, and gender was examined as a moderator of treatment effects. RESULTS: Controlling for regular drinking frequency, participants who received a BMI did not significantly reduce their DG frequency relative to the comparison group in either sample, and the BMI was equally ineffective at reducing DG behavior for men and women. DG-related PCT during the BMI was associated with lower DG frequency at the second follow-up in both Trials. In Trial 1, PCT during the BMI was associated with less steep increases in DG frequency across the course of all follow-ups. Effects of PCT on DG behavior were not moderated by gender. CONCLUSIONS: Findings did not support hypothesized reductions in DG participation following a BMI. Future research should explore whether targeted DG-specific interventions could reduce DG participation and the role of in-session client language in facilitating such change

Student service members/veterans on campus: Challenges for reintegration.

Many returning OIF/OEF/OND Veterans are seeking higher education in an effort to develop a meaningful career and financial stability. Evidence suggests that student service members/ veterans (SSM/Vs) are experiencing less academic success than other students. The purpose of this review is to identify the unique challenges of SSM/Vs and evaluate current campus efforts to facilitate their retention and academic performance. With a focus on SSM/Vs attending colleges and universities, we obtained 57 peer-reviewed and 73 gray literature records published between 2001 and 2015. The current SSM/V literature contains an abundance of gray literature, and the empirical research tends to be limited by cross-sectional design and small sample sizes. SSM/Vs encounter significant personal and environmental challenges when transitioning from the military to college campuses. A variety of services have been developed to address the needs of the SSM/V population, but the efficacy of these services remains largely unknown. In conclusion, there is a clear need to provide education to faculty, students, and staff regarding the experiences of SSM/Vs. Efforts to enhance screening for, availability of, and SSM/V engagement in mental health services would also be beneficial, as would improved availability of and SSM/V access to academic support. All future programs designed to address the unique challenges of SSM/Vs in the academic environment should also be systematically implemented and evaluated

Peer substance use overestimation among French university students: a cross-sectional survey

<p>Abstract</p> <p>Background</p> <p>Normative misperceptions have been widely documented for alcohol use among U.S. college students. There is less research on other substances or European cultural contexts. This study explores which factors are associated with alcohol, tobacco and cannabis use misperceptions among French college students, focusing on substance use.</p> <p>Methods</p> <p>12 classes of second-year college students (n = 731) in sociology, medicine, nursing or foreign language estimated the proportion of tobacco, cannabis, alcohol use and heavy episodic drinking among their peers and reported their own use.</p> <p>Results</p> <p>Peer substance use overestimation frequency was 84% for tobacco, 55% for cannabis, 37% for alcohol and 56% for heavy episodic drinking. Cannabis users (p = 0.006), alcohol (p = 0.003) and heavy episodic drinkers (p = 0.002), are more likely to overestimate the prevalence of use of these consumptions. Tobacco users are less likely to overestimate peer prevalence of smoking (p = 0.044). Women are more likely to overestimate tobacco (p < 0.001) and heavy episodic drinking (p = 0.007) prevalence. Students having already completed another substance use questionnaire were more likely to overestimate alcohol use prevalence (p = 0.012). Students exposed to cannabis prevention campaigns were more likely to overestimate cannabis (p = 0.018) and tobacco use (p = 0.022) prevalence. Other identified factors are class-level use prevalences and academic discipline.</p> <p>Conclusions</p> <p>Local interventions that focus on creating realistic perceptions of substance use prevalence could be considered for cannabis and alcohol prevention in French campuses.</p

Propranolol 0.2% eye micro-drops for retinopathy of prematurity : a prospective phase IIb study

Background: Oral propranolol reduces retinopathy of prematurity (ROP) progression, although not safely. Propranolol 0.1% eye micro-drops administered to newborns with stage 2 ROP are well-tolerated, but not sufficiently effective. Methods: A multi-center open-label trial was conducted to assess the safety and efficacy of propranolol 0.2% eye micro-drops in newborns with stage 1 ROP. The progression of the disease was evaluated with serial ophthalmologic examinations. Hemodynamic, respiratory, biochemical parameters, and propranolol plasma levels were monitored. Demographic and perinatal characteristics, co-morbidities and co-intervention incidences, together with ROP progression, were compared with a historical control group in the same centers participating in the trial. Results: Ninety-eight newborns were enrolled and compared with the historical control group. Populations were not perfectly homogeneous (as demonstrated by the differences in the Apgar score and the different incidence rate in surfactant administration and oxygen exposure). The progression to ROP stage 2 or 3 plus was significantly lower than the incidence expected on the basis of historical data (Risk Ratio 0.521, 95% CI 0.297- 0.916). No adverse effects related to propranolol were observed and the mean propranolol plasma level was significantly lower than the safety cutoff of 20 ng/mL. Unexpectedly, three newborns treated with oral propranolol before the appearance of ROP, showed a ROP that was unresponsive to propranolol eye micro-drops and required laser photocoagulation treatment. Conclusion: Propranolol 0.2% eye micro-drops were well-tolerated and appeared to reduce the ROP progression expected on the basis of a comparison with a historical control group. Propranolol administered too early appears to favor a more aggressive ROP, suggesting that a \u3b2-adrenoreceptor blockade is only useful during the proliferative phase. Further randomized placebo-controlled trials are required to confirm the current results

Electrochemistry of nanozeolite-immobilized cytochrome c in aqueous and nonaqueous solutions

peer-reviewedThe electrochemical properties of cytochrome c (cyt c) immobilized on multilayer nanozeolite-modified electrodes have been examined in aqueous and nonaqueous solutions. Layers of Linde type-L zeolites were assembled on indium tin oxide (ITO) glass electrodes followed by the adsorption of cyt c, primarily via electrostatic interactions, onto modified ITO electrodes. The heme protein displayed a quasi-reversible response in aqueous solution with a redox potential of +324 mV (vs NHE), and the surface coverage (Gamma*) increased linearly for the first four layers and then gave a nearly constant value of 200 pmol cm(-2). On immersion of the modified electrodes in 95% (v/v) nonaqueous solutions, the redox potential decreased significantly, a decrease that originated from changes in both the enthalpy and entropy of reduction. On reimmersion of the modified electrode in buffer, the faradic response immediately returned to its original value. These results demonstrate that nanozeolites are potential stable supports for redox proteins and enzymes.ACCEPTEDpeer-reviewe