Hexagonal vortices enable faster colloidal crystal grain coarsening.

We find that localized rotations of hexagonal clusters of particles occur during rapid dissolution of grain boundary loops in two-dimensional colloidal crystals. These particle vortices, or rotating "granules," are distinct from established models for grain boundary diffusion, which predict that a crystal grain enclosed within another crystal will dissolve at a constant rate. Our measurements of colloidal crystal experiments and Brownian dynamics simulations reveal grain boundary motion that is described by two distinct processes: slow dissolution due to the diffusion of individual particles, and rapid dissolution due to collective granule rotation. In the latter process, hexagonal clusters of particles rotate together in granules whose shape and position are determined by the underlying moiré pattern. Furthermore, these vortices guide cooperative strings of particles that move along the edges of the hexagonal granules. Including this vortex mechanism may improve models for grain coarsening in polycrystalline materials, ultimately offering improved predictions for the time evolution of material properties.

Anticipatory Anxiety, Familiarization, and Performance: Finding the Sweet Spot to Optimize High-Quality Data Collection and Minimize Subject Burden.

Accurate baseline data are essential for researchers to determine an intervention's effects yet may be affected by anticipatory anxiety and assessment familiarity. Familiarization sessions help establish accurate baseline data. High-intensity functional training (HIFT) elicits performance outcomes based on constantly varied workouts. It is unclear how familiarization affects anticipatory anxiety and workout performance among HIFT novices. Familiarization was hypothesized to decrease anxiety and improve workout performance. Sixteen college-aged subjects (62.5% women, 20.2 ± 1.14 years) completed one introductory and four sessions of the same workout. All subjects were recreationally trained with no HIFT experience. State and trait anxiety were assessed at the first session. During the workout sessions, state anxiety (SQALS) was assessed upon arrival at the gym (SQALS 1), after learning the workout protocol (SQALS 2), and when the workout concluded (SQALS 3). A significant main effect of the number of previous sessions on workout performance was observed (p = 0.011). A repeated-measures ANOVA showed a main effect of time on SQALS 1 (p < 0.001), SQALS 2 (p < 0.001), and SQALS 3 (p < 0.001). Our results suggest implementing two familiarization sessions for our HIFT-based workout was sufficient to decrease anxiety and establish a baseline measurement. Future research should examine if this remains true for other types of HIFT-based workouts.

Lionfish (Pterois volitans) as biomonitoring species for oil pollution effects in coral reef ecosystems.

With oil spills, and other sources of aromatic hydrocarbons, being a continuous threat to coral reef systems, and most reef fish species being protected or difficult to collect, the use of the invasive lionfish (Pterois volitans) might be a good model species to monitor biomarkers in potentially exposed fish in the Caribbean and western Atlantic. The rapid expansion of lionfish in the Caribbean and western Atlantic, and the unregulated fishing for this species, would make the lionfish a suitable candidate as biomonitoring species for oil pollution effects. However, to date little has been published about the responses of lionfish to environmental pollutants. For this study lionfish were collected in the Florida Keys a few weeks after Hurricane Irma, which sank numerous boats resulting in leaks of oil and fuel, and during the winter and early spring after that. Several biomarkers indicative of exposure to PAHs (bile fluorescence, cytochrome P450-1A induction, glutathione S-transferase activity) were measured. To establish if these biomarkers are inducible in PAH exposed lionfish, dosing experiments with different concentrations of High Energy Water Accommodated Fraction of crude oil were performed. The results revealed no significant effects in the biomarkers in the field collected fish, while the exposure experiments demonstrated that lionfish did show strong effects in the measured biomarkers, even at the lowest concentration tested (0.3% HEWAF, or 25 µg/l Æ©PAH50). Based on its widespread distribution, relative ease of collection, and significant biomarker responses in the controlled dosing experiment, it is concluded that lionfish has good potential to be used as a standardized biomonitoring species for oil pollution in its neotropical realm.

Use of opioid medications for chronic noncancer pain syndromes in primary care.

OBJECTIVES: To define the spectrum of chronic noncancer pain treated with opioid medications in 2 primary care settings, and the prevalence of psychiatric comorbidity in this patient population. We also sought to determine the proportion of patients who manifested prescription opioid abuse behaviors and the factors associated with these behaviors. DESIGN: A retrospective cohort study. SETTING: A VA primary care clinic and an urban hospital-based primary care center (PCC) located in the northeastern United States. PATIENTS: A random sample of VA patients ( n=50) and all PCC patients ( n=48) with chronic noncancer pain who received 6 or more months of opioid prescriptions during a 1-year period (April 1, 1997 through March 31, 1998) and were not on methadone maintenance. MEASUREMENTS: Information regarding patients' type of chronic pain disorder, demographic, medical, and psychiatric status, and the presence of prescription opioid abuse behaviors was obtained by medical record review. MAIN RESULTS: Low back pain was the most common disorder accounting for 44% and 25% of all chronic pain diagnoses in the VA and PCC samples, respectively, followed by injury-related (10% and 13%), diabetic neuropathy (8% and 10%), degenerative joint disease (16% and 13%), spinal stenosis (10% and 4%), headache (4% and 13%) and other chronic pain disorders (8% and 22%). The median duration of pain was 10 years (range 3 to 50 years) in the VA and 13 years in the PCC sample (range 1 to 49 years). Among VA and PCC patients, the lifetime prevalence rates of psychiatric comorbidities were: depressive disorder (44% and 54%), anxiety disorder (20% and 21%), alcohol abuse/dependence (46% and 31%), and narcotic abuse/dependence (18% and 38%). Prescription opioid abusive behaviors were recorded for 24% of VA and 31% of PCC patients. A lifetime history of a substance use disorder (adjusted odds ratio [OR], 3.8; 95% confidence interval [CI], 1.4 to 10.8) and age (adjusted OR, 0.94; 95% CI, 0.89 to 0.99) were independent predictors of prescription opioid abuse behavior. CONCLUSIONS: A broad spectrum of chronic noncancer pain disorders are treated with opioid medications in primary care settings. The lifetime prevalence of psychiatric comorbidity was substantial in our study population. A significant minority of patients manifested prescription opioid abusive behaviors, and a lifetime history of a substance use disorder and decreasing age were associated with prescription opioid abuse behavior. Prospective studies are needed to determine the potential benefits as well as risks associated with opioid use for chronic noncancer pain in primary care.