A Time-Series Analysis of Crime and Drug Use in New York City

This report summarizes the results of a project which investigated the time series interrelationships between crime, drug use, police, and arrests in New York City. We use monthly data from 1970 through 1990 for New York City. We plot the individual time series for five different non-drug crimes, arrest rates for these crimes, drug deaths, number of police officers, and drug arrests in New York City. We find that drug usage, as proxied by drug deaths, increased from the mid-1980's to about 1988-1989. At the same time, felony drug arrests increased substantially. During the mid-1980's, there were increases in murders, assaults, and motor vehicle thefts. Robberies increased in the later 1980s and burglaries declined throughout the 1980s. Arrest rates and total arrests for non-drug crimes did not decline during this period of increased drug arrests. In a multivariate analysis, we found that the three property crimes investigated - robberies, burglaries and motor vehicle thefts - increased when there were unexpected increases in drug usage. We did not find such a relationship between drug use and murders or assaults, holding constant arrest rates and police. In addition, we found evidence of police deterrence, either directly, or through arrests, of property-related and assault offenses, but not for murders. Thus, in a time-series approach, we are able to find a causal relationship between drug usage and property-related felonies.

The first stars of the Rho Ophiuchi Dark Cloud. XMM-Newton view of Rho Oph and its neighbors

Star formation in molecular clouds can be triggered by the dynamical action of winds from massive stars. Furthermore, X-ray and UV fluxes from massive stars can influence the life time of surrounding circumstellar disks. We present the results of a 53 ks XMM-Newton observation centered on the Rho Ophiuchi A+B binary system. Rho Ophiiuchi lies in the center of a ring of dust, likely formed by the action of its winds. This region is different from the dense core of the cloud (L1688 Core F) where star formation is at work. X-rays are detected from Rho Ophiuchi as well as a group of surrounding X-ray sources. We detected 89 X-ray sources, 47 of them have at least one counterpart in 2MASS + All-WISE catalogs. Based on IR and X-ray properties, we can distinguish between young stellar objects (YSOs) belonging to the cloud and background objects. Among the cloud members, we detect 3 debris disk objects and 22 disk-less / Class III young stars. We show that these stars have ages in $5-10$ Myr, and are significantly older than the YSOs in L1688. We speculate that they are the result of an early burst of star formation in the cloud. An X-ray energy of $\ge5\times10^{44}$ ergs has been injected into the surrounding medium during the past $5$ Myr, we discuss the effects of such energy budget in relation to the cloud properties and dynamics.Comment: 17 pages, 9 figures, 7 tables. Accepted for publication to Astronomy & Astrophysic

Evaluation of Modification of the Upper Batavia Dam on the Fox River, Illinois

Progress Report, Federal Aid Project F-136-R Segment 6Report issued on: August 2004Submitted to Office of Water Resources, Illinois Department of Natural Resource

Outcoupling from a Bose-Einstein condensate with squeezed light to produce entangled atom laser beams

We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We model the multimode dynamics of the output field and show that a significant amount of squeezing can be transfered from an optical mode to a propagating atom laser beam. We use this to demonstrate that two-mode squeezing can be used to produce twin atom laser beams with continuous variable entanglement in amplitude and phase.Comment: 11 pages, 14 figure

Do early-life exposures explain why more advantaged children get eczema? Findings from the U.K. Millennium Cohort Study

Background: Atopic dermatitis (eczema) in childhood is socially patterned, with higher incidence in more advantaged populations. However, it is unclear what factors explain the social differences. Objectives: To identify early-life risk factors for eczema, and to explore how early-life risk factors explain any differences in eczema. Methods: We estimated odds ratios (ORs) for ever having had eczema by age 5 years in 14 499 children from the U.K. Millennium Cohort Study (MCS), with a focus on maternal, antenatal and early-life risk factors and socioeconomic circumstances (SECs). Risk factors were explored to assess whether they attenuated associations between SECs and eczema. Results: Overall 35·1% of children had ever had eczema by age 5 years. Children of mothers with degree-level qualifications vs. no educational qualifications were more likely to have eczema (OR 1·52, 95% confidence interval 1·31–1·76), and there was a gradient across the socioeconomic spectrum. Maternal atopy, breastfeeding (1–6 weeks and ≥ 6 months), introduction of solids under 4 months or cow's milk under 9 months, antibiotic exposure in the first year of life and grime exposure were associated with an increased odds of having eczema. Female sex, Pakistani and Bangladeshi ethnicity, smoking during pregnancy, exposure to environmental tobacco smoke and having more siblings were associated with reduced odds for eczema. Controlling for maternal, antenatal and early-life characteristics (particularly maternal smoking during pregnancy, breastfeeding and number of siblings) reduced the OR for eczema to 1·26 (95% confidence interval 1·03–1·50) in the group with the highest educational qualifications compared with the least. Conclusions: In a representative U.K. child cohort, eczema was more common in more advantaged children. This was explained partially by early-life factors including not smoking during pregnancy, breastfeeding and having fewer siblings

An Atom Laser Based on Raman Transitions

In this paper we present an atom laser scheme using a Raman transition for the output coupling of atoms. A beam of thermal atoms (bosons) in a metastable atomic state $|1 >$ are pumped into a multimode atomic cavity. This cavity is coupled through spontaneous emission to a single mode of another cavity for the ground atomic state, $|2 >$. Above a certain threshold pumping rate a large number of atoms, $N_2$, builds up in this single quantum state and transitions to the ground state of the cavity become enhanced by a factor $(N_2 + 1)$. Atoms in this state are then coupled to the outside of the cavity with a Raman transition. This changes the internal state of the atom and imparts a momentum kick, allowing the atoms to leave the system.Comment: 8 pages, 4 postscript figures, uses RevTex, home page at http://online.anu.edu.au/Physics/Welcome.html (Some aspects of the exact physical model have changed from original version. Other general improvements included

Quantum kinetic theory model of a continuous atom laser

We investigate the feasible limits for realising a continuously evaporated atom laser with high-temperature sources. A plausible scheme for realising a truly continuous atom laser is to outcouple atoms from a partially condensed Bose gas, whilst continuously reloading the system with non-condensed thermal atoms and performing evaporative cooling. Here we use quantum kinetic theory to model this system and estimate feasible limits for the operation of such a scheme. For sufficiently high temperatures, the figure of merit for the source is shown to be the phase-space flux. The dominant process limiting the usage of sources with low phase-space flux is the three-body loss of the condensed gas. We conclude that certain double-magneto-optical trap (MOT) sources may produce substantial mean condensate numbers through continuous evaporation, and provide an atom laser source with a narrow linewidth and reasonable flux.Comment: 28 pages, 5 figure

Resonance fluorescence in a band gap material: Direct numerical simulation of non-Markovian evolution

A numerical method of calculating the non-Markovian evolution of a driven atom radiating into a structured continuum is developed. The formal solution for the atomic reduced density matrix is written as a Markovian algorithm by introducing a set of additional, virtual density matrices which follow, to the level of approximation of the algorithm, all the possible trajectories of the photons in the electromagnetic field. The technique is perturbative in the sense that more virtual density matrices are required as the product of the effective memory time and the effective coupling strength become larger. The number of density matrices required is given by $3^{M}$ where $M$ is the number of timesteps per memory time. The technique is applied to the problem of a driven two-level atom radiating close to a photonic band gap and the steady-state correlation function of the atom is calculated.Comment: 14 pages, 9 figure