Placing Confidence Limits on Polarization Measurements

The determination of the true source polarization given a set of measurements is complicated by the requirement that the polarization always be positive. This positive bias also hinders construction of upper limits, uncertainties, and confidence regions, especially at low signal-to-noise levels. We generate the likelihood function for linear polarization measurements and use it to create confidence regions and upper limits. This is accomplished by integrating the likelihood function over the true polarization (parameter space), rather than the measured polarization (data space). These regions are valid for both low and high signal-to-noise measurements.Comment: 8 pages, 3 figures, 1 table, submitted to PAS

Representation of differential operators in wavelet basis

AbstractExisting work on the representation of operators in one-dimensional, compactly-supported, orthonormal wavelet bases is extended to two dimensions. The nonstandard form of the representation of operators is given in separable two-dimensional, periodic, orthonormal wavelet bases. The matrix representation of the partial-differential operators ∂x and ∂y are constructed and a closed form formula for the matrix representation of a general partial-differential operator g(∂x, ∂y) is derived, where g is an analytic function

The Removal of Artificially Generated Polarization in SHARP Maps

We characterize the problem of artificial polarization for the Submillimeter High Angular Resolution Polarimeter (SHARP) through the use of simulated data and observations made at the Caltech Submillimeter Observatory (CSO). These erroneous, artificial polarization signals are introduced into the data through misalignments in the bolometer sub-arrays plus pointing drifts present during the data-taking procedure. An algorithm is outlined here to address this problem and correct for it, provided that one can measure the degree of the sub-array misalignments and telescope pointing drifts. Tests involving simulated sources of Gaussian intensity profile indicate that the level of introduced artificial polarization is highly dependent upon the angular size of the source. Despite this, the correction algorithm is effective at removing up to 60% of the artificial polarization during these tests. The analysis of Jupiter data taken in January 2006 and February 2007 indicates a mean polarization of 1.44%+/-0.04% and 0.95%+/-0.09%, respectively. The application of the correction algorithm yields mean reductions in the polarization of approximately 0.15% and 0.03% for the 2006 and 2007 data sets, respectively.Comment: 19 pages, 7 figure

Sri Lankan Tamil Refugees in India: Conceptual Framework of Repatriation Success

Repatriation to Sri Lanka has become a primary challenge to Sri Lankan Tamil refugees in Indian refugee camps, and a matter of significant public discussion in India and Sri Lanka. Anxiety about repatriation among Sri Lankan Tamil refugees and lack of initiation from the Sri Lankan government threatens the development of a coherent repatriation strategy. This article proposes a conceptual framework of repatriation success for Sri Lankan Tamil refugees, which the Sri Lankan government, non-governmental agencies, and Sri Lankan Tamil refugees may use to develop a concrete strategy for repatriation. Based upon the study results of two of the authors’ repatriation studies, this article identifies and describes the four key concepts of the repatriation framework: livelihood development, language and culture awareness, social relationships, and equal citizenship within a nation.Le rapatriement vers le Sri Lanka constitue l’un des défis principaux que doivent affronter les réfugiés tamouls d’origine sri lankaise vivant dans les camps de réfugiés en Inde, et un sujet important de débats publics en Inde ainsi qu’au Sri Lanka. L’inquiétude envers le rapatriement parmi les réfugiés tamouls d’origine sri lankaise et l’absence de démarches de la part du gouvernement sri lankais compromet le développement d’une stratégie cohérente de rapatriement. L’objectif principal de cet article est de proposer un cadre conceptuel pour un rapatriement réussi à l’égard des réfugiés tamouls d’origine sri lankaise que le gouvernement sri lankais, les agences non gouvernementales et les réfugiés dont il est question pourraient utiliser afin de développer une stratégie concrète pour le rapatriement. Fondé sur les résultats provenant des études de recherche sur le rapatriement effectuées par deux des auteurs, l’article identifie et décrit les quatre concepts clés du cadre de rapatriement: le développement des moyens de subsistance, une prise de conscience linguistique et culturelle, les liens sociaux et l’égalité de la citoyenneté dans le contexte national

On the Stability of Oscillatory Pipe Flows

The linear stability of pure oscillatory pipe flow is investigated by solving the linearized disturbance equations as an initial value problem. The importance of the initial conditions on transient dynamics of the flow is analyzed. It is shown that transient growth can play an important role in the development of flow instability. The accuracy of the quasi-steady assumption is assessed. It is shown that the growth rates obtained with this assumption deviate considerably from the results obtained with a direct numerical solution of the linearized initial value problem

Advances in reproductive biology and seed production systems of Eucalyptus: The case of Eucalyptus globulus

Eucalyptus globulus is the main eucalypt species grown in Australian plantations. The focus on seedling deployment systems, coupled with exploitation of large, open-pollinated base populations for breeding purposes over the last two decades, has required a detailed understanding of the reproductive biology of this species. We review our research on the reproductive biology of E. globulus, with a focus on it’s breeding system and advances made in seed production systems. While most improved seed is still obtained from open-pollinated seedling or grafted seed orchards, the development of the one-stop/single-visit pollination procedure has revolutionised the breeding and deployment of this species. The reduced costs of controlled pollination has meant full pedigree-control can now be maintained in large advanced generation breeding populations and E. globulus is one of the few eucalypt species where large-scale production of manually pollinated seed for family forestry is being undertaken

History of Childhood Abuse and Mother-infant Interaction: a Systematic Review of Observational Studies

Literature that has examined maternal self-reported history of abuse and an observational assessment of infant-mother interaction were reviewed. Electronic databases were searched, and studies that met predefined criteria were included. Fourteen (12 independent samples) studies were included and assessed for quality using the Effective Public Health Practice Project tool (National Collaborating Centre for Methods and Tools, 2008). Ten of the 14 studies found a direct or an indirect relationship between self-reported abuse and observed caregiving. The small number of studies and variation in sample characteristics and measurement limit conclusions. Of the studies that were rated of the highest quality, there is some consistency showing that the effect of maternal abuse history on caregiving may be via a third variable (i.e., stress reactivity or depressive symptoms). The current review discusses strengths and limitations of the existing literature and offers suggestions for future research

Microwave Kinetic Inductance Detector (MKID) Camera Testing for Submillimeter Astronomy

Developing kilopixel focal planes for incoherent submm- and mm-wave detectors remains challenging due to either the large hardware overhead or the complexity of multiplexing standard detectors. Microwave kinetic inductance detectors (MKIDs) provide a efficient means to produce fully lithographic background-limited kilopixel focal planes. We are constructing an MKID-based camera for the Caltech Submillimeter Observatory with 576 spatial pixels each simultaneously sensitive in 4 bands at 230, 300, 350, and 400 GHz. The novelty of MKIDs has required us to develop new techniques for detector characterization. We have measured quasiparticle lifetimes and resonator Qs for detector bath temperatures between 200 mK and 400 mK. Equivalent lifetime measurements were made by coupling energy into the resonators either optically or by driving the third harmonic of the resonator. To determine optical loading, we use both lifetime and internal Q measurements, which range between 15,000 and 30,000 for our resonators. Spectral bandpass measurements confirm the placement of the 230 and 350 GHz bands. Additionally, beam maps measurements conform to expectations. The same device design has been characterized on both sapphire and silicon substrates, and for different detector geometries. We also report on the incorporation of new shielding to reduce detector sensitivity to local magnetic fields

Phase contrast imaging using photothermally induced phase transitions in liquid crystals

Phase contrast imaging is performed for live biological species using photothermal induced birefringence in dye doped liquid crystals. Using typical 4-f configuration, when liquid crystal cell is at back focal plane of Fourier lens, low spatial frequencies at center of Fourier spectrum are intense enough to induce local liquid crystal molecules into isotropic phase, whereas high spatial frequencies on the edges are not intense enough and remain in anisotropic phase. This results in π/2 phase difference between high and low spatial frequencies. This simple, inexpensive, all-optical, user-friendly, self-adaptive phase contrast imaging technique using low-power laser offers several distinct advantages