Bound and free waves in non-collinear second harmonic generation

We analyze the relationship between the bound and the free waves in the noncollinear SHG scheme, along with the vectorial conservation law for the different components arising when there are two pump beams impinging on the sample with two different incidence angles. The generated power is systematically investigated, by varying the polarization state of both fundamental beams, while absorption is included via the Herman and Hayden correction terms. The theoretical simulations, obtained for samples which are some coherence length thick show that the resulting polarization mapping is an useful tool to put in evidence the interference between bound and free waves, as well as the effect of absorption on the interference patternComment: 10 pages, 7 figure. to be published on Optics Expres

Counter-propagating entangled photons from a waveguide with periodic nonlinearity

The conditions required for spontaneous parametric down-conversion in a waveguide with periodic nonlinearity in the presence of an unguided pump field are established. Control of the periodic nonlinearity and the physical properties of the waveguide permits the quasi-phase matching equations that describe counter-propagating guided signal and idler beams to be satisfied. We compare the tuning curves and spectral properties of such counter-propagating beams to those for co-propagating beams under typical experimental conditions. We find that the counter-propagating beams exhibit narrow bandwidth permitting the generation of quantum states that possess discrete-frequency entanglement. Such states may be useful for experiments in quantum optics and technologies that benefit from frequency entanglement.Comment: submitted to Phys. Rev.

Interview with Andrea Maker by Andrea L’Hommedieu

Biographical NoteAndrea (Cianchette) Maker was born in 1956 in Waterville, Maine, and grew up in Pittsfield, Maine. She came from a large, politically active family of both Democrats and Republicans. Her family’s construction business, Cianbro, evolved and grew during her childhood. While in college in New Hampshire, Maker interned for Bill Cohen. She attended the University of Maine School of Law for two years, then completed her third year at American University in Washington, D.C. During her third year of law school she worked for Senator Mitchell in the mailroom, drafting responses to atypical letters. After law school, Maker became a lobbyist representing clients in the Maine legislature on a number of issues. At the time of this interview she served on the board of the Susan Curtis Foundation and worked at Martin’s Point Health Care. SummaryInterview includes discussion of: family and educational background; Pittsfield, Maine; Cianchette Brothers construction company (Cianbro): Chuck, Bud, and Lunk; growing up in Pittsfield; her father’s (Chuck’s) political life and friendship with Mitchell; shadowing Mitchell in 1977; Paula Silsby; law school; working in the mailroom of George Mitchell’s office; Gayle Cory and Christine Williams; an anecdote about having Mitchell over for dinner; Maker’s uncles in politics, Carl, Ival, Peter, Norris and Kenneth Cianchette; interning for Bill Cohen and a comparison between working for Cohen and for Mitchell; working with Susan Collins and Mike Hastings while in Cohen’s office; and Mitchell’s career and legacy

Theory of four-wave mixing of matter waves from a Bose-Einstein condensate

A recent experiment [Deng et al., Nature 398, 218(1999)] demonstrated four-wave mixing of matter wavepackets created from a Bose-Einstein condensate. The experiment utilized light pulses to create two high-momentum wavepackets via Bragg diffraction from a stationary Bose-Einstein condensate. The high-momentum components and the initial low momentum condensate interact to form a new momentum component due to the nonlinear self-interaction of the bosonic atoms. We develop a three-dimensional quantum mechanical description, based on the slowly-varying-envelope approximation, for four-wave mixing in Bose-Einstein condensates using the time-dependent Gross-Pitaevskii equation. We apply this description to describe the experimental observations and to make predictions. We examine the role of phase-modulation, momentum and energy conservation (i.e., phase-matching), and particle number conservation in four-wave mixing of matter waves, and develop simple models for understanding our numerical results.Comment: 18 pages Revtex preprint form, 13 eps figure

The price of tumor control: an analysis of rare side effects of anti-CTLA-4 therapy in metastatic melanoma from the ipilimumab network

Background: Ipilimumab, a cytotoxic T-lymphocyte antigen-4 (CTLA-4) blocking antibody, has been approved for the treatment of metastatic melanoma and induces adverse events (AE) in up to 64% of patients. Treatment algorithms for the management of common ipilimumab-induced AEs have lead to a reduction of morbidity, e.g. due to bowel perforations. However, the spectrum of less common AEs is expanding as ipilimumab is increasingly applied. Stringent recognition and management of AEs will reduce drug-induced morbidity and costs, and thus, positively impact the cost-benefit ratio of the drug. To facilitate timely identification and adequate management data on rare AEs were analyzed at 19 skin cancer centers. Methods and Findings: Patient files (n = 752) were screened for rare ipilimumab-associated AEs. A total of 120 AEs, some of which were life-threatening or even fatal, were reported and summarized by organ system describing the most instructive cases in detail. Previously unreported AEs like drug rash with eosinophilia and systemic symptoms (DRESS), granulomatous inflammation of the central nervous system, and aseptic meningitis, were documented. Obstacles included patientś delay in reporting symptoms and the differentiation of steroid-induced from ipilimumab-induced AEs under steroid treatment. Importantly, response rate was high in this patient population with tumor regression in 30.9% and a tumor control rate of 61.8% in stage IV melanoma patients despite the fact that some patients received only two of four recommended ipilimumab infusions. This suggests that ipilimumab-induced antitumor responses can have an early onset and that severe autoimmune reactions may reflect overtreatment. Conclusion: The wide spectrum of ipilimumab-induced AEs demands doctor and patient awareness to reduce morbidity and treatment costs and true ipilimumab success is dictated by both objective tumor responses and controlling severe side effects

Parity forbidden excitations of Sr2CuO2Cl2 revealed by optical third-harmonic spectroscopy

We present the first study of nonlinear optical third harmonic generation in the strongly correlated charge-transfer insulator Sr2CuO2Cl2. For fundamental excitation in the near-infrared, the THG spectrum reveals a strongly resonant response for photon energies near 0.7 eV. Polarization analysis reveals this novel resonance to be only partially accounted for by three-photon excitation to the optical charge-transfer exciton, and indicates that an even-parity excitation at 2 eV, with a_1g symmetry, participates in the third harmonic susceptibility.Comment: Requires RevTeX v4.0beta

Ethnic and Gender Differences in Identifying Gifted Students: A Multi-Cultural Analysis

The purpose of this study was to examine ethnic and gender differences in using DISCOVER, a performance-based assessment, for identifying gifted students. The sample consisted of 941 students from grades K-5 belonging to six ethnicities: White Americans, African-Americans, Hispanics, Native-Americans, South Pacific/Pacific Islanders, and Arabs. The 5 X 6 MANOVA (activity x ethnicity) yielded a significant interaction, but no main effect for either activity or ethnicity was found. Plots of the interaction showed that South Pacific/Pacific Islanders scored highest on Oral Linguistic whereas White Americans scored highest in Math and Native Americans scored highest in Spatial Artistic activity. No gender differences in identification were found. All ethnic groups were well represented among identified students, suggesting that DISCOVER might be used in different countries and with culturally diverse students

Vacuum Squeezing in Atomic Media via Self-Rotation

When linearly polarized light propagates through a medium in which elliptically polarized light would undergo self-rotation, squeezed vacuum can appear in the orthogonal polarization. A simple relationship between self-rotation and the degree of vacuum squeezing is developed. Taking into account absorption, we find the optimum conditions for squeezing in any medium that can produce self-rotation. We then find analytic expressions for the amount of vacuum squeezing produced by an atomic vapor when light is near-resonant with a transition between various low-angular-momentum states. Finally, we consider a gas of multi-level Rb atoms, and analyze squeezing for light tuned near the D-lines under realistic conditions.Comment: 10 pages, 6 figures; Submitted to PR

Individuals living with lupus: findings from the LUPUS UK Members Survey 2014

Systemic lupus erythematosus (SLE) is a complex and unpredictable disease which varies greatly among patients and has a significant impact on an individual’s daily living and quality of life. A better understanding of the patients’ experiences with the disease is vital to the effective management of the disease. LUPUS UK, a national UK-registered charity supporting people with systemic and discoid lupus, conducted a UK-wide survey of individuals living with lupus in order to provide foundation information to support and identify gaps needing further research. An anonymous survey was sent to 5660 LUPUS UK members in order to obtain demographic, diagnosis, symptom and treatment information. A total of 2527 surveys were returned by 2371 females (mean age 56.9 years, SD 13.6) and 156 males, (mean age 60.9 years, SD 15.7). Individuals reported a mean (SD) time to diagnosis from the first symptom of 6.4 (9.5) years, with 47% (n ¼ 1186) initially being given a different diagnosis prior to lupus. Fatigue/weakness (91%, n ¼ 2299) and joint pain/swelling (77.4%, n ¼ 1957) were the most common symptoms that interfere with daily activities, while 73% (n ¼ 1836) noted having some problems that make them unable to carry out their usual daily activities. Thirty-two per cent (n ¼ 806) were also seeking support beyond traditional pharmacological treatments, such as acupuncture and massage. This study highlights the range and frequency of symptoms difficult to live with on a daily basis and support areas needing further research to improve patients’ well-being