Humans use directed and random exploration to solve the explore-exploit dilemma.

All adaptive organisms face the fundamental tradeoff between pursuing a known reward (exploitation) and sampling lesser-known options in search of something better (exploration). Theory suggests at least two strategies for solving this dilemma: a directed strategy in which choices are explicitly biased toward information seeking, and a random strategy in which decision noise leads to exploration by chance. In this work we investigated the extent to which humans use these two strategies. In our "Horizon task," participants made explore-exploit decisions in two contexts that differed in the number of choices that they would make in the future (the time horizon). Participants were allowed to make either a single choice in each game (horizon 1), or 6 sequential choices (horizon 6), giving them more opportunity to explore. By modeling the behavior in these two conditions, we were able to measure exploration-related changes in decision making and quantify the contributions of the two strategies to behavior. We found that participants were more information seeking and had higher decision noise with the longer horizon, suggesting that humans use both strategies to solve the exploration-exploitation dilemma. We thus conclude that both information seeking and choice variability can be controlled and put to use in the service of exploration.

HIPPA compliance for vendors and suppliers.

Between 30 to 45% of breaches in Protected Health Information (PHI) involve vendors, yet in most cases it is the hospital that is held liable for the breach. In this article, the author explores the practice of relying on vendors to conduct their own background checks of employees they assign to hospitals. He provides guidance on how hospitals can insure that such checks are up to the standards of the hospital's own background procedures without taking over that responsibility from vendors.

Background checks: coming up short.

In this article, the author spells out the flaws and omissions in the way background checks are conducted, especially by hospitals. He provides pointers on avoiding these flaws and their potential costs.

Forensic patients--who is watching them?

Does your hospital security department have the right and/or responsibility for checking out the qualifications and practices of private contractors hired by law enforcement to guard forensic patients? In this article, the author explains why you should.

Security's role in morgue operations: needed--a foolproof plan.

If handling the remains of dead patients is a responsibility of your security department, or you are being pressured to take on the role because of budget cuts, the need to anticipate and plan for complications which may arise is critical, the author points out.

Second-year results of an obesity prevention program at the Dow Chemical Company.

OBJECTIVE: Evaluate innovative, evidence-based approaches to organizational/supportive environmental interventions aimed at reducing the prevalence of obesity among Dow employees after 2 years of implementation. METHODS: A quasi-experimental study design compared outcomes for two levels of intervention intensity with a control group. Propensity scores were used to weight baseline differences between intervention and control subjects. Difference-in-differences methods and multilevel modeling were used to control for individual and site-level confounders. RESULTS: Intervention participants maintained their weight and body mass index, whereas control participants gained 1.3 pounds and increased their body mass index values by 0.2 over 2 years. Significant differences in blood pressure and cholesterol values were observed when comparing intervention employees with controls. At higher intensity sites, improvements were more pronounced. CONCLUSIONS: Environmental interventions at the workplace can support weight management and risk reduction after 2 years.

Shifting liability? when police officers 'drop off' a person in the ER.

Police layoffs in the present economic downturn may increase a law enforcement practice of leaving before the persons they bring to hospital ERs are evaluated by the clinical staff. In effect, says the author, they are transferring liability for the patient to the hospital and its security staff. Many hospitals, he reports, are unaware of the liability risks they are undertaking in such situations.

1-Phenyl-1-propyne on Cu(111): TOFMS TPD, XPS, UPS, and 2PPE Studies.

The bonding properties of 1-phenyl-1-propyne (PP, C6H5CCCH3) on Cu(111) at 100 K have been studied using temperature-programmed desorption (TPD), and X-ray, ultraviolet, and two-photon photoemission spectroscopies (XPS, UPS, and 2PPE). In TPD, there is no evidence for dissociation. Multilayer desorption occurs at 187 K, and monolayer desorption occurs at 320 (83.5 kJ/mol) and 390 K (102.4 kJ/mol), with the latter dominating. Based on the calibrated C(1s) XPS, the saturation monolayer coverage is one PP per four surface Cu atoms. The broad and asymmetric C(1s) intensity profile of the monolayer can be resolved into three symmetric components, with peaks at 283.6, 284.5, and 285.2 eV and intensities of 2:6:1, respectively. These are attributed, respectively, to acetylenic carbons bound to Cu, phenyl, and methyl carbons. The monolayer valence band ultraviolet photoemission spectrum profile contains four resonances attributable to PP perturbed by interactions with the Cu(111) substrate. With the exception of the highest occupied molecular orbital (HOMO) that is shifted by 0.4 eV, these are uniformly shifted by 1 eV further from the Fermi level for the multilayer. Calculated electron density plots of the occupied orbitals coupled with UPS profiles suggest a spectator role for the phenyl group and bonding to Cu via the acetylenic carbons. The adsorption of 1.0 monolayer (ML) of PP on Cu(111) lowers the work function by 0.85 eV. Using 2PPE, two unoccupied orbitals were identified at 1.0 (U1*-LUMO) and 0.6 eV (U2*-image state) below the vacuum level. A chemisorption model consistent with these spectroscopic results and the major chemisorption peak in TPD involve di-sigma-bonding of the acetylenic carbons to a pair of second-nearest neighbor surface Cu atoms (cross-bridge).

Using formative research to develop environmental and ecological interventions to address overweight and obesity.

OBJECTIVE: This paper presents the formative research phase of a large multi-site intervention study conducted to inform the feasibility of introducing environmental and ecological interventions. RESEARCH METHODS AND PROCEDURES: Using mixed methods that included an environmental assessment, climate survey, leadership focus groups and interviews, and archival data, information was collected on employee health and job factors, the physical environment, social-organizational environment, and current health programs. RESULTS: Results show that 83% of employees at the study sites were overweight or obese. Leadership was very supportive of health initiatives and felt integrating the strategies into organizational operations would increase their likelihood of success. Environmental assessment scores ranged from 47 to 19 on a 100-point scale. Health services personnel tended to view the organizational climate for health more positively than site leadership (mean of 3.6 vs. 3.0, respectively). DISCUSSION: Intervention strategies chosen included increasing healthy food choices in vending, cafeterias, and company meetings, providing a walking path, targeting messages, developing site goals, training leaders, and establishing leaders at the work group level.

Selective catalytic oxidation of ammonia to nitrogen on atomic oxygen precovered Au(111).

We demonstrate ammonia oxidation promoted by an atomic oxygen precovered Au(111) surface. The selectivity of the catalytic oxidation of ammonia to NO or N2 on Au(111) is tunable by the atomic oxygen coverage. We propose that N2 and NO are produced via the recombination reactions of Nad + Nad and Nad + Oad.

A spectroscopic investigation of carbon-carbon bond formation by methylene insertion on a Ag(111) surface: mechanism and kinetics.

Using reflection-absorption infrared spectroscopy (RAIRS) and temperature-programmed reaction spectroscopy (TPRS), we have investigated the cross-coupling reaction between CH(2)(a) and CF(3)(a) on a Ag(111) surface. CH(2)(a) and CF(3)(a) are generated by thermal decomposition of adsorbed CH(2)I(2) and CF(3)I. RAIRS results unambiguously demonstrate that CH(2)(a) inserts into the Ag-CF(3) bond to produce adsorbed CF(3)CH(2)(a), which upon heating selectively undergoes beta-fluorine elimination to form CH(2)=CF(2). Increasing the CH(2)(a) and CF(3)(a) coverage leads to the sequential insertion of CH(2)(a) into Ag-CF(3), as evidenced by CH(2)CH(2)CF(3)(a) formation detected with RAIRS. Prior to the insertion reaction, the evidence favors islanding of fragments. The methylene insertion reaction is so facile that it occurs at cryogenic temperatures (120 K). Time-resolved RAIRS (TR-RAIRS) results at selected temperatures reveal an activation energy of 5.8 kJ/mol. Our results provide, for the first time, direct spectroscopic information about the mechanism and kinetics of the methylene insertion reaction.