Metasurface-based hybrid optical cavities for chiral sensing

Quantum metasurfaces, i.e., two-dimensional subwavelength arrays of quantum emitters, can be employed as mirrors towards the design of hybrid cavities, where the optical response is given by the interplay of a cavity-confined field and the surface modes supported by the arrays. We show that, under external magnetic field control, stacked layers of quantum metasurfaces can serve as helicity-preserving cavities. These structures exhibit ultranarrow resonances and can enhance the intensity of the incoming field by orders of magnitude, while simultaneously preserving the handedness of the field circulating inside the resonator, as opposed to conventional cavities. The rapid phase shift in the cavity transmission around the resonance can be exploited for the sensitive detection of chiral scatterers passing through the cavity. We discuss possible applications of these resonators as sensors for the discrimination of chiral molecules.Comment: 6+11 pages, 2+3 figure

Efficacy of Formal Training and Education on Foster Child Abuse in Newly Hired Nurses

Foster care child abuse cases are more prevalent in the United States. Evidence suggests a significant gap between self reports of abuse and reports by health professionals. 120 nurses will be selected to participate in formal training. A time series design will be used to test the participant’s knowledge before, immediately after, and six months after the formal training. The data collected will be analyzed using descriptive statistics for demographic variables and an one-way ANOVA test will determine significant differences among group scores. Limitations to the study include accessibility to sample size, turnover of participants, the self reporting nature of the questionnaires, test taker anxiety, the ability of the training presenters, and the participants’ knowledge they are being observed

The Hard X-Ray Luminosity Function of High-Redshift (3<z≲53<z\lesssim 5) Active Galactic Nuclei

We present the hard-band ($2-10\,\mathrm{keV}$) X-ray luminosity function (HXLF) of $0.5-2\,\mathrm{keV}$ band selected AGN at high redshift. We have assembled a sample of 141 AGN at $3<z\lesssim5$ from X-ray surveys of different size and depth, in order to sample different regions in the $L_X - z$ plane. The HXLF is fitted in the range $\mathrm{logL_X\sim43-45}$ with standard analytical evolutionary models through a maximum likelihood procedure. The evolution of the HXLF is well described by a pure density evolution, with the AGN space density declining by a factor of $\sim10$ from $z=3$ to 5. A luminosity-dependent density evolution model which, normally, best represents the HXLF evolution at lower redshift, is also consistent with the data, but a larger sample of low-luminosity ($\mathrm{logL_X}<44$), high-redshift AGN is necessary to constrain this model. We also estimated the intrinsic fraction of AGN obscured by a column density $\mathrm{logN_H}\geq23$ to be $0.54\pm0.05$, with no strong dependence on luminosity. This fraction is higher than the value in the Local Universe, suggesting an evolution of the luminous ($\mathrm{L_X>10^{44}\mathrm{erg\,s^{-1}}}$) obscured AGN fraction from $z=0$ to $z>3$.Comment: MNRAS, Accepted 2014 September 23. Received 2014 September 10; in original form 2014 August 5; 19 pages, 11 figures, 5 table

Fluid Intelligence Is (Much) More than Working Memory Capacity: An Experimental Analysis

Empirical evidence suggests a great positive association between measures of fluid intelligence and working memory capacity, which implied to some researchers that fluid intelligence is little more than working memory. Because this conclusion is mostly based on correlation analysis, a causal relationship between fluid intelligence and working memory has not yet been established. The aim of the present study was therefore to provide an experimental analysis of this relationship. In a first study, 60 participants worked on items of the Advanced Progressive Matrices (APM) while simultaneously engaging in one of four secondary tasks to load specific components of the working memory system. There was a diminishing effect of loading the central executive on the APM performance, which could explain 15% of the variance in the APM score. In a second study, we used the same experimental manipulations but replaced the dependent variable with complex working memory span tasks from three different domains. There was also a diminishing effect of the experimental manipulation on span task performance, which could now explain 40% of the variance. These findings suggest a causal effect of working memory functioning on fluid intelligence test performance, but they also imply that factors other than working memory functioning must contribute to fluid intelligence

Solvent Dependency of the UV-Vis Spectrum of Indenoisoquinolines: Role of Keto-Oxygens as Polarity Interaction Probes.

Indenoisoquinolines are the most promising non-campthotecins topoisomerase IB inhibitors. We present an integrated experimental/computational investigation of the UV-Vis spectra of the IQNs parental compound (NSC314622) and two of its derivatives (NSC724998 and NSC725776) currently undergoing Phase I clinical trials. In all the three compounds a similar dependence of the relative absorption intensities at 270 nm and 290 nm on solvent polarity is found. The keto-oxygens in positions 5 and 11 of the molecular scaffold of the molecule are the principal chromophores involved in this dependence. Protic interactions on these sites are also found to give rise to absorptions at wavelengthsolution, due to the stabilization of highly polarized tautomers of the molecule. These results suggest that the keto-oxygens are important polarizable groups that can act as useful interactors with the molecular receptor, providing at the same time an useful fingerprint for the monitoring of the drug binding to topoisomerase IB

NEPAD Southern African Water Centres of Excellence - Report on task JLP1.1 and JLP1.2

The NEPAD SANWATCE network investigation in collaboration with the European Commission Joint Research Centre looks into the skills shortages that exist in the SADC region in water resources management, and further discusses how the Water Centres of Excellence could better address sector expertise and advocacy for sector development in the region.JRC.H.1-Water Resource

Finding Rare AGN: X-ray Number Counts of Chandra Sources in Stripe 82

We present the first results of a wide area X-ray survey within the Sloan Digital Sky Survey (SDSS) Stripe 82, a 300 deg$^2$ region of the sky with a substantial investment in multi-wavelength coverage. We analyzed archival {\it Chandra} observations that cover 7.5 deg$^2$ within Stripe 82 ("Stripe 82 ACX"), reaching 4.5$\sigma$ flux limits of 7.9$\times10^{-16}$, 3.4$\times10^{-15}$ and 1.8$\times10^{-15}$ erg s$^{-1}$ cm$^{-2}$ in the soft (0.5-2 keV), hard (2-7 keV) and full (0.5-7 keV) bands, to find 774, 239 and 1118 X-ray sources, respectively. Three hundred twenty-one sources are detected only in the full band and 9 sources are detected solely in the soft band. Utilizing data products from the {\it Chandra} Source Catalog, we construct independent Log$N$-Log$S$ relationships, detailing the number density of X-ray sources as a function of flux, which show general agreement with previous {\it Chandra} surveys. We compare the luminosity distribution of Stripe 82 ACX with the smaller, deeper CDF-S + E-CDFS surveys and with {\it Chandra}-COSMOS, illustrating the benefit of wide-area surveys in locating high luminosity AGN. We also investigate the differences and similarities of X-ray and optical selection to uncover obscured AGN in the local Universe. Finally, we estimate the population of AGN we expect to find with increased coverage of 100 deg$^2$ or 300 deg$^2$, which will provide unprecedented insight into the high redshift, high luminosity regime of black hole growth currently under-represented in X-ray surveys.Comment: Accepted for publication in MNRAS, 15 pages, 6 Figures, 2 Table