The deuteron: a mini-review

We review some recent results for elastic electron deuteron scattering (deuteron form factors) and photodisintegration of the deuteron, with emphasis on the recent high energy data from Jefferson Laboratory (JLab).Comment: 14 pages, 11 figures, Invited talk given to the Conference on Mesons & Light Nuclei, held in Prague, Czech Republic, July 2- 6, 200

Electromagnetic structure of the deuteron

Recent measurements of the deuteron electromagnetic structure functions A, B, and $T_{20}$ extracted from high energy elastic $ed$ scattering, and the cross sections and asymmetries extracted from high energy photodisintegration $\gamma+d\to n+p$, are reviewed and compared to theory. The theoretical calculations range from nonrelativistic and relativistic models using the traditional meson and baryon degrees of freedom, to effective field theories, to models based on the underlying quark and gluon degrees of freedom of QCD, including nonperturbative quark cluster models and perturbative QCD. We review what has been learned from these experiments, and discuss why elastic $ed$ scattering and photodisintegration seem to require very different theoretical approaches, even though they are closely related experimentally.Comment: review paper; 93 pages, 35 figure

Global shallow water magnetohydrodynamic waves in the solar tachocline

We derive analytical solutions and dispersion relations of global magnetic Poincar\'e (magneto-gravity) and magnetic Rossby waves in the approximation of shallow water magnetohydrodynamics. The solutions are obtained in a rotating spherical coordinate system for strongly and weakly stable stratification separately in the presence of toroidal magnetic field. In both cases magnetic Rossby waves split into fast and slow magnetic Rossby modes. In the case of strongly stable stratification (valid in the radiative part of the tachocline) all waves are slightly affected by the layer thickness and the toroidal magnetic field, while in the case of weakly stable stratification (valid in the upper overshoot layer of the tachocline) magnetic Poincar\'e and fast magnetic Rossby waves are found to be concentrated near the solar equator, leading to equatorially trapped waves. However, slow magnetic Rossby waves tend to concentrate near the poles, leading to polar trapped waves. The frequencies of all waves are smaller in the upper weakly stable stratification region than in the lower strongly stable stratification one

Silicon Alley: A Framework for New York City’s Entrepreneurship Ecosystem and its Public Policy Considerations

As cities like New York emerge as hubs of innovation resolved in using technology and engaging non-governmental actors, this white paper pursues an analysis of the actors in the urban innovation ecosystem to pinpoint what makes these ecosystems distinct from their suburban counterparts. New York is unique in the way it describes innovation and entrepreneurs, pursuing an open and loose definition, enabling it to engage stakeholders and actors in a way that other places cannot. By bringing multiple perspectives and stakeholders into the fold, New York is able to pursue entrepreneurship hand in hand with civic duties, fostering an environment that centers public and social good in many cases. Actors then blur the boundaries between being entrepreneurs, public servants, and civil society members. This paper explores the urban dynamics of innovation ecosystems, focusing on the role of New York in fostering and orchestrating them. Section I analyzes the disruptive role of emerging technologies in society, focusing on workforce and skills. Section II defines urban innovation ecosystems, assesses the forces that are propelling this new spatial geography of innovation, and provides insights into redefining the new dynamics and while arguing that the urban innovation ecosystem remains distinct from traditional “innovation ecosystems.” Section III provides a case study of New York’s innovation ecosystem and lists the multiple assets of the city as an innovation district. Finally, it puts forward policy considerations for a diverse set of stakeholders, including policy makers, technology companies, and civil society on how leveraging technology and entrepreneurship ecosystems can catalyze innovation; and illustrates policy actions applied to a number of challenges

Socioeconomic status and anxiety as predictors of antidepressant treatment response and suicidal ideation in older adults.

BACKGROUND: Separate reports from the maintenance treatment for late-life depression (MTLD) trials have shown that low socioeconomic status (SES) and anxiety symptoms at the time of treatment initiation predict lower levels of response to antidepressant treatment and higher levels of suicidal ideation in older adults. AIM: To determine whether SES and anxiety independently contribute to worse treatment outcomes, as indicated by persistence of depressive symptoms during treatment and the persistence of suicidal ideation. Consistent with prior evidence that sociodemographic factors and clinical history are both prognostic of depression treatment efficacy, we hypothesized that SES and pre-existing anxiety symptoms will both predict lower levels of response to treatment and higher levels of suicidal ideation. METHOD: Secondary analyses of data from the MTLD trials. RESULTS: Regression analyses which controlled for comorbid anxiety indicated that residents of middle- and high-income census tracts were more likely to respond to treatment (HR, 1.63; 95%CI, 1.08-2.46) and less likely to report suicidal ideation during treatment (OR, 0.51; 95%CI, 0.28-0.90) than residents of low income census tracts. The same regression models indicated that pre-existing anxiety symptoms were independently related to lower treatment response (HR, 0.73; 95%CI, 0.60-0.89) and higher risk of suicidal ideation (OR, 1.45; 95%CI, 0.98-2.14). CONCLUSION: These findings demonstrate the importance of treating anxiety symptoms during the course of treatment for late-life depression and, at the same time, addressing barriers to treatment response related to low SES

A Dark Census: Statistically Detecting the Satellite Populations of Distant Galaxies

In the standard structure formation scenario based on the cold dark matter paradigm, galactic halos are predicted to contain a large population of dark matter subhalos. While the most massive members of the subhalo population can appear as luminous satellites and be detected in optical surveys, establishing the existence of the low mass and mostly dark subhalos has proven to be a daunting task. Galaxy-scale strong gravitational lenses have been successfully used to study mass substructures lying close to lensed images of bright background sources. However, in typical galaxy-scale lenses, the strong lensing region only covers a small projected area of the lens's dark matter halo, implying that the vast majority of subhalos cannot be directly detected in lensing observations. In this paper, we point out that this large population of dark satellites can collectively affect gravitational lensing observables, hence possibly allowing their statistical detection. Focusing on the region of the galactic halo outside the strong lensing area, we compute from first principles the statistical properties of perturbations to the gravitational time delay and position of lensed images in the presence of a mass substructure population. We find that in the standard cosmological scenario, the statistics of these lensing observables are well approximated by Gaussian distributions. The formalism developed as part of this calculation is very general and can be applied to any halo geometry and choice of subhalo mass function. Our results significantly reduce the computational cost of including a large substructure population in lens models and enable the use of Bayesian inference techniques to detect and characterize the distributed satellite population of distant lens galaxies.Comment: 21 pages + appendices, 7 figures. v2: Some derivations streamlined, extended appendices. Matches version published in PR