Scaling and singularities in the entrainment of globally-coupled oscillators

The onset of collective behavior in a population of globally coupled oscillators with randomly distributed frequencies is studied for phase dynamical models with arbitrary coupling. The population is described by a Fokker-Planck equation for the distribution of phases which includes the diffusive effect of noise in the oscillator frequencies. The bifurcation from the phase-incoherent state is analyzed using amplitude equations for the unstable modes with particular attention to the dependence of the nonlinearly saturated mode $|\alpha_\infty|$ on the linear growth rate $\gamma$. In general we find $|\alpha_\infty|\sim \sqrt{\gamma(\gamma+l^2D)}$ where $D$ is the diffusion coefficient and $l$ is the mode number of the unstable mode. The unusual $(\gamma+l^2D)$ factor arises from a singularity in the cubic term of the amplitude equation.Comment: 11 pages (Revtex); paper submitted to Phys. Rev. Let

Applied Meteorology Unit (AMU)

This report summarizes the Applied Meteorology Unit (AMU) activities for the second quarter of Fiscal Year 2008 (January - March 2008). Projects described are: (1) Peak Wind Tool for User Launch Commit Criteria (LCC), (2) Peak Wind Tool for General Forecasting, (3) Situational Lightning Climatologies for Central Florida. Phase III, (4) Volume Averaged Height Integrated Radar Reflectivity (VAHIRR), (5) Impact of Local Sensors, (6) Radar Scan Strategies for the PAFB WSR-74C Replacement and (7) WRF Wind Sensitivity Study at Edwards Air Force Base

Surface Characterization of Polycarbonate Parts from Selective Laser Sintering

Surfaces of polycarbonate Selective Laser Sintering parts are investigated to determine the characteristics affecting part quality. Surfaces are obtained from experiments by varying four factors, namely, layer thickness, laser power, part orientation, and build angle. First, spatial modes on SLS surfaces are decomposed using a qualitative spectral analysis in an attempt to find their origins. Thermal modes on the top surfaces of polycarbonate SLS parts result in the other modes being obscured; melting and part curl are concluded to be the dominant modes on these surfaces. Furthermore, surface modes resulting from building the part at an angle to the powder bed are identified and modeled. Then, mathematical measures are computed for the surfaces to determine surface precision quantitatively. An analysis-of-variance study is performed to reveal the trends in surface precision with respect to control factors. Surface precision is shown to change significantly with laser power and part orientation, and trade-offs with part strength are presented.Mechanical Engineerin

Prospective evaluation of the impact of intermenstrual bleeding on natural fertility

To evaluate the impact of an episode of intermenstrual bleeding on the probability of conception in a menstrual cycle (fecundability)

Prospective evaluation of luteal phase length and natural fertility

OBJECTIVE: To evaluate the impact of a short luteal phase on fecundity. DESIGN: Prospective time-to-pregnancy cohort study. SETTING: Not applicable. PATIENT(S): Women trying to conceive, ages 30-44 years, without known infertility. INTERVENTION(S): Daily diaries, ovulation prediction testing, standardized pregnancy testing. MAIN OUTCOME MEASURE(S): Subsequent cycle fecundity. RESULT(S): Included in the analysis were 1,635 cycles from 284 women. A short luteal phase (≤11 days including the day of ovulation) occurred in 18% of observed cycles. Mean luteal phase length was 14 days. Significantly more women with a short luteal phase were smokers. After adjustment for age, women with a short luteal phase had 0.82 times the odds of pregnancy in the subsequent cycle immediately following the short luteal phase compared with women without a short luteal phase. Women with a short luteal length in the first observed cycle had significantly lower fertility after the first 6 months of pregnancy attempt, but at 12 months there was no significant difference in cumulative probability of pregnancy. CONCLUSION(S): Although an isolated cycle with a short luteal phase may negatively affect short-term fertility, incidence of infertility at 12 months was not significantly higher among these women. CLINICAL TRIAL REGISTRATION NUMBER: NCT01028365

Processes controlling the seasonal variations of 210Pb and 7Be at the Mt. Cimone WMO-GAW global station, Italy: A model analysis

We apply the Global Modeling Initiative (GMI) chemistry and transport model 14 driven by the NASA\u2019s MERRA assimilated meteorological data to simulate the seasonal variations of two radionuclide aerosol tracers (terrigenous 210Pb and cosmogenic 7 15 Be) at the 16 WMO-GAW station of Mt. Cimone (44\ub012\u2019 N, 10\ub042\u2019 E, 2165 m asl, Italy), which is 17 representative of free-tropospheric conditions most of the year, during 2005 with an aim to 18 understand the roles of transport and precipitation scavenging processes in controlling their 19 seasonality. The total precipitation field in the MERRA data set is evaluated with the Global 20 Precipitation Climatology project (GPCP) observations, and a generally good agreement is found. The model reproduces reasonably the observed seasonal pattern of 210 21 Pb concentrations, characterized by a wintertime minimum due to lower 222 22 Rn emissions and weaker uplift from the boundary layer and summertime maxima resulting from strong convection over the continent. The observed seasonal behavior of 7Be concentrations shows a winter minimum, a summer maximum, and a secondary spring maximum. The model captures the observed 7Be 4 pattern in winter-spring, which is linked to the larger stratospheric influence during spring. However, the model tends to underestimate the observed 7Be concentrations in summer, 6 partially due to the sensitivity to spatial sampling in the model. Model sensitivity experiments 7 indicate a dominant role of precipitation scavenging (versus dry deposition and convection) in controlling the seasonality of 210Pb and 7 Be concentrations at Mt. Cimone

Individual Differences in Dopamine Are Associated with Reward Discounting in Clinical Groups But Not in Healthy Adults.

Some people are more willing to make immediate, risky, or costly reward-focused choices than others, which has been hypothesized to be associated with individual differences in dopamine (DA) function. In two studies using PET imaging, one empirical (Study 1: N = 144 males and females across 3 samples) and one meta-analytic (Study 2: N = 307 across 12 samples), we sought to characterize associations between individual differences in DA and time, probability, and physical effort discounting in human adults. Study 1 demonstrated that individual differences in DA D2-like receptors were not associated with time or probability discounting of monetary rewards in healthy humans, and associations with physical effort discounting were inconsistent across adults of different ages. Meta-analytic results for temporal discounting corroborated our empirical finding for minimal effect of DA measures on discounting in healthy individuals but suggested that associations between individual differences in DA and reward discounting depend on clinical features. Addictions were characterized by negative correlations between DA and discounting, but other clinical conditions, such as Parkinson's disease, obesity, and attention-deficit/hyperactivity disorder, were characterized by positive correlations between DA and discounting. Together, the results suggest that trait differences in discounting in healthy adults do not appear to be strongly associated with individual differences in D2-like receptors. The difference in meta-analytic correlation effects between healthy controls and individuals with psychopathology suggests that individual difference findings related to DA and reward discounting in clinical samples may not be reliably generalized to healthy controls, and vice versa.SIGNIFICANCE STATEMENT Decisions to forgo large rewards for smaller ones due to increasing time delays, uncertainty, or physical effort have been linked to differences in dopamine (DA) function, which is disrupted in some forms of psychopathology. It remains unclear whether alterations in DA function associated with psychopathology also extend to explaining associations between DA function and decision making in healthy individuals. We show that individual differences in DA D2 receptor availability are not consistently related to monetary discounting of time, probability, or physical effort in healthy individuals across a broad age range. By contrast, we suggest that psychopathology accounts for observed inconsistencies in the relationship between measures of DA function and reward discounting behavior

Limits to Interstellar C_4 and C_5 Towards zeta Ophiuchi

We have made a sensitive search for the origin bands in the known electronic transitions of the linear carbon chains C_4 and C_5 at 3789 and 5109 A towards zeta Oph (A_V <= 1). The incentive was a recent detection of C_3 in this interstellar cloud with a column density of 1.6 x 10^12 cm^-2 plus the availability of laboratory gas phase spectra of C_4 and C_5. Further, some models of diffuse interstellar clouds predict that the abundance of these latter species should be within an order of magnitude of C_3. Despite achieving S/N of 2300 to 2600 per pixel at a resolution of ~110,000, the searches were negative, leading to 3 sigma upper limits to the column density of N(C_5) = 2 x 10^11 cm^-2 and N(C_4) = 4 x 10^12-13 cm^-2 where these values rely on theoretically calculated oscillator strengths. The implication of these limits are discussed on the choice of molecules for study in future attempts to identify the carriers of the stronger diffuse interstellar bands.Comment: 12 pages, 3 figure

Sentinel Case of Candida auris in the Western United States Following Prolonged Occult Colonization in a Returned Traveler from India.

Candida auris is an emerging multidrug-resistant yeast with high mortality. We report the sentinel C. auris case on the United States West Coast in a patient who relocated from India. We identified close phylogenetic relatedness to the South Asia clade and ERG11 Y132F and FKS1 S639Y mutations potentially explaining antifungal resistance