Hospital initiatives in promoting smoking cessation: A 12-year follow-up.

In the present study, the availability of smoking cessation programs (SCP) was surveyed in the same randomly selected USA hospitals in 2000 and 2012. A total of 102 USA hospitals were randomly selected for this survey. Each hospital website was searched for the topic of smoking cessation. In the second phase of the survey, the main switchboard number of each hospital was anonymously telephoned and the 'stop smoking clinic' was requested. The phone survey results showed that the percentage of hospital switchboard calls that were connected to a SCP remained identical at 47% in 2000 and 2012. The results for the internet availability of SCP on hospital websites improved from 30% in 2000 to 47% in 2012. There were more hospitals that added additional SCP information (27%) compared with those that removed SCP information (15%) by 2012. Among the 57% of hospitals that showed no change in internet SCP information, 22% remained positive for such information while 35% remained negative. The phone survey of hospitals showed that 47% of USA hospitals were able to connect a caller to a SCP in the years 2000 and 2012. While there was no reduction over the 12 years, there was no increase in the percentage of hospital switchboards that connected to a SCP. Availability of SCP information on hospital web sites improved to a limited extent; increasing from 30% of sites in 2000 to 47% in 2012. Providing SCP on a hospital website is easy and free, for example adding a link to QuitNet or QuitLink. The present study adds to information gathered 12 years earlier, and is unusual in being able to provide follow-up data on the same set of hospitals studied previously.

Effect of epitope position on neutralization by anti-human immunodeficiency virus monoclonal antibody 2F5.

The membrane-proximal region of the human immunodeficiency virus type 1 (HIV-1) transmembrane protein (TM) is critical for envelope (Env)-mediated membrane fusion and contains the target for broadly reactive neutralizing antibody 2F5. It has been proposed that 2F5 neutralization might involve interaction of its long, hydrophobic, complementarity-determining region (CDR) H3, with adjacent viral membrane. Using Moloney murine leukemia virus (MLV) as a tool, we examined the effect of epitope position on 2F5 neutralization. When the 2F5 epitope was inserted in the proline-rich region of MLV Env surface protein (SU), 2F5 blocked cell fusion and virus infection, whereas MLV with a hemagglutinin (HA) epitope at the same position was not neutralized by anti-HA, even though the antibodies bound their respective Envs on the surface of infected cells and viruses equally well. When the 2F5 epitope was inserted in the MLV Env TM at a position comparable to its natural position in HIV-1 TM, 2F5 antibody blocked Env-mediated cell fusion. Epitope position had subtle effects on neutralization by 2F5: the antibody concentration for 50% inhibition of cell fusion was more than 10-fold lower when the 2F5 epitope was in SU than in TM, and inhibition was less complete at high concentrations of antibody; we discuss possible explanations for these effects of epitope position. Since membrane proximity was not required for neutralization by 2F5 antibody, we speculate that the CDR H3 of 2F5 contributes to neutralization by destabilizing an adjacent protein rather than by inserting into an adjacent membrane.

Evolving cooperation: the role of individual recognition.

To evaluate the role of individual recognition in the evolution of cooperation, we formulated and analyzed genetic algorithm model (EvCo) for playing the Iterated Prisoner's Dilemma (IPD) game. Strategies compete against each other during each generation, and successful strategies contribute more of their attributes to the next generation. Each strategy is encoded on a 'chromosome' that plays the IPD, responding to the sequences of most recent responses by the interacting individuals (chromosomes). The analysis reported in this paper considered different memory capabilities (one to five previous interactions), pairing continuities (pairs of individuals remain together for about one, two, five, or 1000 consecutive interactions), and types of individual recognition (recognition capability was maximal, nil, or allowed to evolve between these limits). Analysis of the results focused on the frequency of mutual cooperation in pairwise interactions (a good indicator of overall success in the IPD) and on the extent to which previous responses by the focal individual and its partner were associated with the partner's identity (individual recognition). Results indicated that a fixed, substantial amount of individual recognition could maintain high levels of mutual cooperation even at low pairing continuities, and a significant but limited capability for individual recognition evolved under selection. Recognition generally increased mutual cooperation more when the recent responses of individuals other than the current partner were ignored. Titrating recognition memory under selection using a fitness cost suggested that memory of the partner's previous responses was more valuable than memory of the focal's previous responses. The dynamics produced to date by EvCo are a step toward understanding the evolution of social networks, for which additional benefits associated with group interactions must be incorporated.