2,475 research outputs found

    Polarization-controlled single photons

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    Vacuum-stimulated Raman transitions are driven between two magnetic substates of a rubidium-87 atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatio-temporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.Comment: 4 pages, 3 figure

    Meeting the Diverse Needs of the Poor

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    Forums such as this develop our understanding of current efforts to bring about positive change for America\u27s poor. The Journal\u27s compilation and dissemination of important, thoughtful essays on poverty is laudable. The one thing that is clear about the poor and the homeless is that their problems are multi-faceted. No one theory or group can provide all the solutions. People are poor and homeless for a wide variety of reasons, and they need different kinds of help. Providing more income assistance will not cure poverty, and providing more housing will not remedy homelessness. Neither the public nor the private sector can find solutions without the cooperation of each other. Since the sources of poverty and homelessness are varied, the poor and the homeless have needs that are personal to each individual or family. Basic needs are food, shelter and clothing. Some need medical care, mental health counseling and medication, legal aid, benefits counseling, job training, job and housing placement assistance, alcohol and other drug abuse counseling, literacy and other education assistance, day care and a wide variety of other social services. The obligation to provide for all of these needs is not simply based on charity or government largess. The obligation is a matter of justice, remembering that justice is not simply treating everyone equally, but treating everyone according to their needs. You will see in the pages that follow that much research focuses upon poverty and its consequences. After reading the following papers, one could understandably conclude that because the needs of the poor are so complex, poverty is an intractable social condition about which little can be done. Hopefully the solutions and proposals offered in the following articles will elicit debate and criticism and, ultimately, positive action. Many people who abhor injustices such as homelessness or poverty may sincerely disagree about practical approaches to achieve justice. Although the following papers present divergent views, the changes they propose in social welfare policy merit consideration. It would be a shame if some of the innovative proposals contained in this issue of the Journal go unused because poverty seems implacable

    Benchmarking Treatment Response in Tourette’s Disorder: A Psychometric Evaluation and Signal Detection Analysis of the Parent Tic Questionnaire

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    This study assessed the psychometric properties of a parent-reported tic severity measure, the Parent Tic Questionnaire (PTQ), and used the scale to establish guidelines for delineating clinically significant tic treatment response. Participants were 126 children ages 9 to 17 who participated in a randomized controlled trial of Comprehensive Behavioral Intervention for Tics (CBIT). Tic severity was assessed using the Yale Global Tic Severity Scale (YGTSS), Hopkins Motor/Vocal Tic Scale (HMVTS) and PTQ; positive treatment response was defined by a score of 1 (very much improved) or 2 (much improved) on the Clinical Global Impressions – Improvement (CGI-I) scale. Cronbach’s alpha and intraclass correlations (ICC) assessed internal consistency and test-retest reliability, with correlations evaluating validity. Receiver- and Quality-Receiver Operating Characteristic analyses assessed the efficiency of percent and raw-reduction cutoffs associated with positive treatment response. The PTQ demonstrated good internal consistency (α = 0.80 to 0.86), excellent test-retest reliability (ICC = .84 to .89), good convergent validity with the YGTSS and HM/VTS, and good discriminant validity from hyperactive, obsessive-compulsive, and externalizing (i.e., aggression and rule-breaking) symptoms. A 55% reduction and 10-point decrease in PTQ Total score were optimal for defining positive treatment response. Findings help standardize tic assessment and provide clinicians with greater clarity in determining clinically meaningful tic symptom change during treatment

    Photon-Photon Entanglement with a Single Trapped Atom

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    An experiment is performed where a single rubidium atom trapped within a high-finesse optical cavity emits two independently triggered entangled photons. The entanglement is mediated by the atom and is characterized both by a Bell inequality violation of S=2.5, as well as full quantum-state tomography, resulting in a fidelity exceeding F=90%. The combination of cavity-QED and trapped atom techniques makes our protocol inherently deterministic - an essential step for the generation of scalable entanglement between the nodes of a distributed quantum network.Comment: 5 pages, 4 figure

    GROWTH AND NUTRIENT ACCUMULATION AS CONTROLLED BY OXYGEN SUPPLY TO PLANT ROOTS

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    Tumour burden in early stage Hodgkin's disease: the single most important prognostic factor for outcome after radiotherapy.

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    One hundred and forty-two patients with Hodgkin's disease PS I or II were treated with total or subtotal nodal irradiation as part of a prospective randomized trial in the Danish National Hodgkin Study during the period 1971-83. They were followed till death or--at the time of this analysis--from 15 to 146 months after initiation of therapy. The initial tumour burden of each patient was assessed, combining tumour size of each involved region and number of regions involved. Tumour burden thus assessed proved to be the single most important prognostic factor with regard to disease free survival. Other known prognostic factors such as number of involved regions, mediastinal size, pathological stage, systemic symptoms, and ESR were related to tumour burden and lost their prognostic significance in a multivariate analysis. The only other factors of independent significance were histologic subtype and, to a lesser extent, sex. Combining tumour burden and histologic subtype made it possible to single out a group of patients with a very poor disease free survival. These patients also had a poorer survival from Hodgkin's disease and thus clearly candidates for additional initial treatment

    Pearl Millet: a green bridge for Lepidopteran Pests.

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    Abstract: This study evaluated the occurrence of lepidopteran pests on millet cultivated in off-season in the state of Mato Grosso, Brazil. Larvae were collected from May to July 2013 in an area of 145 hectares located in Tangará da Serra, MT. After being collected, caterpillars were kept in the laboratory and fed an artificial diet until the pupal stage. After emergence, adults were dry mounted, identified, and deposited in the entomological collection of Embrapa Cerrados, Planaltina, Distrito Federal, Brazil. Adults obtained from 117 caterpillars were identified as Mocis latipes (Guenée), Spodoptera frugiperda (J.E. Smith), Helicoverpa armigera (Hübner), H. zea (Boddie), Mythimna (Pseudaletia) sequax Franclemont, Urbanus proteus (Linnaeus), and Leucania latiuscula Herrich-Schäffer. This study describes the first record of lepidopteran pests on millet plants in the state of Mato Grosso, and the incidence of lepidopterans in the system that uses millet as cover crop represents a risk of the occurrence of insect pests on subsequent crops on the straw of this grass

    Lasiothyris luminosa (Lepidoptera: Tortricidae): a new grapevine pest in northeastern Brazil.

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    The little-known Neotropical tortricid moth Lasiothyris luminosa (Razowski& Becker) is reported for the first time as a grapevine pest in Northeastern Brazil. A diagnosis based on morphological characters including the genitalia is provided for both sexes, together with a preliminary description of economic damage caused by the larval stage. In addition, we sequenced a partial region of the cytochrome oxidase subunit I gene from specimens from the region, and reconstructed phylogenetic relationships using representative lineages of closely related tortricids as terminals. The larvais endophagous, feeding on the inflorescence from closed buds before flower anthesistoopen flowers and later, inside fruits at different maturation stages, causing them to rot. Preliminary surveys carried out on a few farms indicate that the effective damage may reach circa 10% of table-grape production in the region

    Spodoptera frugiperda (Lepidoptera: Noctuidae) updated host plants and new records.

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    Conteúdo do volume 2: Ácaros; Biologia, fisiologia, morfologia; Controle biológico com bactérias entomopatogênicas; Controle biológico com fungos entomopatológicos; Controle biológico com nematoides; Controle biológico com parasitoides; Controle biológico com predadores; Ecologia e biodiversidade; Educação e etnoentomologia; Entomologia florestal; Entomologia Forense; Entomologia médica e veterinária; Entomologia molecular; Manejo integrado de pragas; Organismos geneticamente modificados; Plantas inseticidas; Polinização; Pragas quarentenárias e invasivas; Resistência de insetos a táticas de controle; Resistência de plantas a insetos; Semioquímicos e comportamento; Sistemática e taxonomia; Tecnologia de aplicação; Controle biológico com vírus entomopatogênicos; Controle químico
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