804 research outputs found

    Development of Lumped Element Kinetic Inductance Detectors for NIKA

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    Lumped-element kinetic inductance detectors(LEKIDs) have recently shown considerable promise as direct absorption mm-wavelength detectors for astronomical applications. One major research thrust within the N\'eel Iram Kids Array (NIKA) collaboration has been to investigate the suitability of these detectors for deployment at the 30-meter IRAM telescope located on Pico Veleta in Spain. Compared to microwave kinetic inductance detectors (MKID), using quarter wavelength resonators, the resonant circuit of a LEKID consists of a discrete inductance and capacitance coupled to a feedline. A high and constant current density distribution in the inductive part of these resonators makes them very sensitive. Due to only one metal layer on a silicon substrate, the fabrication is relatively easy. In order to optimize the LEKIDs for this application, we have recently probed a wide variety of individual resonator and array parameters through simulation and physical testing. This included determining the optimal feed-line coupling, pixel geometry, resonator distribution within an array (in order to minimize pixel cross-talk), and resonator frequency spacing. Based on these results, a 144-pixel Aluminum array was fabricated and tested in a dilution fridge with optical access, yielding an average optical NEP of ~2E-16 W/Hz^1/2 (best pixels showed NEP = 6E-17 W/Hz^1/2 under 4-8 pW loading per pixel). In October 2010 the second prototype of LEKIDs has been tested at the IRAM 30 m telescope. A new LEKID geometry for 2 polarizations will be presented. Also first optical measurements of a titanium nitride array will be discussed.Comment: 5 pages, 12 figures; ISSTT 2011 Worksho

    Electronics and data acquisition demonstrator for a kinetic inductance camera

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    A prototype of digital frequency multiplexing electronics allowing the real time monitoring of kinetic inductance detector (KIDs) arrays for mm-wave astronomy has been developed. It requires only 2 coaxial cables for instrumenting a large array. For that, an excitation comb of frequencies is generated and fed through the detector. The direct frequency synthesis and the data acquisition relies heavily on a large FPGA using parallelized and pipelined processing. The prototype can instrument 128 resonators (pixels) over a bandwidth of 125 MHz. This paper describes the technical solution chosen, the algorithm used and the results obtained

    Gender differences in lung cancer risk by smoking: a multicentre case-control study in Germany and Italy

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    Several studies in the past have shown appreciably higher lung cancer risk estimates associated with smoking exposure among men than among women, while more recent studies in the USA report just the opposite. To evaluate this topic in a European population we conducted a case-control study of lung cancer in three German and three Italian centres. Personal interviews and standardized questionnaires were used to obtain detailed life-long smoking and occupational histories from 3723 male and 900 female cases and 4075 male and 1094 female controls. Lung cancer risk comparing ever-smokers with never-smokers was higher among men (odds ratios (OR) adjusted for age and centre = 16.1, 95% confidence interval (CI) 12.8-20.3) than among women (OR = 4.2, CI 3.5-5.1). Because the smoking habits of women were different from men, we conducted more detailed analyses using comparable levels of smoking exposure. After restriction to smokers and adjustment for other smoking variables, risk estimates did not differ appreciably between genders. The analysis of duration of smoking (0-19, 20-39, 40+ years) adjusted for cigarette consumption and time since quitting smoking revealed similar risk estimates in men (OR = 1.0, 3.3 [CI 2.6-4.2], 4.1 [CI 3.1-5.6]) and women (OR = 1.0, 2.7 [CI 1.7-4.1], 3.3 [CI 1.9-5.8]). The same was true of the analysis of average or cumulative smoking consumption, and also of analyses stratified by different histological types. We conclude that for comparable exposure to tobacco smoke, the risk of lung cancer is comparable in women and men

    NIKA: A millimeter-wave kinetic inductance camera

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    Current generation millimeter wavelength detectors suffer from scaling limits imposed by complex cryogenic readout electronics. To circumvent this it is imperative to investigate technologies that intrinsically incorporate strong multiplexing. One possible solution is the kinetic inductance detector (KID). In order to assess the potential of this nascent technology, a prototype instrument optimized for the 2 mm atmospheric window was constructed. Known as the N\'eel IRAM KIDs Array (NIKA), it was recently tested at the Institute for Millimetric Radio Astronomy (IRAM) 30-meter telescope at Pico Veleta, Spain. The measurement resulted in the imaging of a number of sources, including planets, quasars, and galaxies. The images for Mars, radio star MWC349, quasar 3C345, and galaxy M87 are presented. From these results, the optical NEP was calculated to be around 1×10−151 \times 10^{-15} W/ / Hz1/2^{1/2}. A factor of 10 improvement is expected to be readily feasible by improvements in the detector materials and reduction of performance-degrading spurious radiation.Comment: Accepted for publication in Astronomy & Astrophysic

    Social support, simpatía, and hypertension prevalence in Hispanics/Latinos: Findings from the HCHS/SOL Sociocultural Ancillary Study.

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    There is a significant burden of hypertension in the United States, which extends to the large and growing Hispanic/Latino population. Previous literature suggests that psychosocial factors are related to hypertension in Hispanics/Latinos. However, cultural factors unique to this population have been largely understudied in this context. The purpose of the current investigation was to examine the association of hypertension prevalence with social support and simpatía, a Hispanic/Latino cultural value emphasizing social harmony. Cross-sectional data from 5,313 adult Hispanics/Latinos, age 18 to 75 years, representing multiple heritage groups were collected as part of the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. Contrary to predictions, higher social support was related to higher odds of hypertension prevalence across models (OR = 1.11, 95% CI: 1.02, 1.22). In the final main effects logistic regression model, higher simpatía was related to lower odds of hypertension (OR = .83, 95% CI: .77, .90). Sex modified the link between simpatía and hypertension, with significant effects for men but not women. A 1 SD increase in simpatía was associated with 36% lower odds of hypertension in Hispanic/Latino men. The findings suggest that social support was inversely related with hypertension prevalence and that simpatía may be a protective cultural characteristic in relation to hypertension in the Hispanic/Latino population, but only in men. These results contribute to a growing discourse about the role of Hispanic/Latino cultural values in cardiovascular health

    Neutrino induced transitions between the ground states of the A=12 triad

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    Neutrino induced reactions on 12^{12}C, an ingredient of liquid scintillators, have been studied in several experiments. We show that for currently available neutrino energies, Eν≤E_{\nu} \le 300 MeV, calculated exclusive cross sections 12^{12}Cgs(ν,l)_{gs}(\nu,l)12^{12}Ngs_{gs} for both muon and electron neutrinos are essentially model independent, provided the calculations simultaneously describe the rates of several other reactions involving the same states or their isobar analogs. The calculations agree well with the measured cross sections, which can be therefore used to check the normalization of the incident neutrino spectrum and the efficiency of the detector.Comment: 9 pages REVTEX, 2 postscript figures, text and figures available at http://www.krl.caltech.edu/preprints/MAP.htm

    Neighborhood environment and metabolic risk in Hispanics/Latinos from the Hispanic community health study/study of Latinos

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    Introduction This study examines the associations of neighborhood environments with BMI, HbA1c, and diabetes across 6 years in Hispanic/Latino adults. Methods Participants from the Hispanic Community Health Study/Study of Latinos San Diego site (n=3,851, mean age=39.4 years, 53.3% women, 94.0% Mexican heritage) underwent assessment of metabolic risk factors and diabetes status (categorized as normoglycemia, prediabetes, and diabetes) at baseline (2008–2011) and approximately 6 years later (2014–2017). In the Study of Latinos Community and Surrounding Areas Study ancillary study (2015–2020), participant baseline addresses were geocoded, and neighborhoods were defined using 800-meter circular buffers. Neighborhood variables representing socioeconomic deprivation, residential stability, social disorder, walkability, and greenness were created using Census and other public databases. Analyses were conducted in 2020–2021. Results Complex survey regression analyses revealed that greater neighborhood socioeconomic deprivation was associated with higher BMI (β=0.14, p<0.001) and HbA1c (β=0.08, p<0.01) levels and a higher odds of worse diabetes status (i.e., having prediabetes versus normoglycemia and having diabetes versus prediabetes; OR=1.25, 95% CI=1.06, 1.47) at baseline. Greater baseline neighborhood deprivation also was related to increasing BMI (β=0.05, p<0.01) and worsening diabetes (OR=1.27, 95% CI=1.10, 1.46) statuses, whereas social disorder was related to increasing BMI levels (β=0.05, p<0.05) at Visit 2. There were no associations of expected protective factors of walkability, greenness, or residential stability. Conclusions Neighborhood deprivation and disorder were related to worse metabolic health in San Diego Hispanic/Latino adults of mostly Mexican heritage. Multilevel interventions emphasizing individual and structural determinants may be most effective in improving metabolic health among Hispanic/Latino individuals

    Importance of basophil activation testing in insect venom allergy

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    <p>Abstract</p> <p>Background</p> <p>Venom immunotherapy (VIT) is the only effective treatment for prevention of serious allergic reactions to bee and wasp stings in sensitized individuals. However, there are still many questions and controversies regarding immunotherapy, like selection of the appropriate allergen, safety and long term efficacy.</p> <p>Methods</p> <p>Literature review was performed to address the role of basophil activation test (BAT) in diagnosis of venom allergy.</p> <p>Results</p> <p>In patients with positive skin tests or specific IgE to both honeybee and wasp venom, IgE inhibition test can identify sensitizing allergen only in around 15% and basophil activation test increases the identification rate to around one third of double positive patients. BAT is also diagnostic in majority of patients with systemic reactions after insect stings and no detectable IgE. High basophil sensitivity to allergen is associated with a risk of side effects during VIT. Persistence of high basophil sensitivity also predicts a treatment failure of VIT.</p> <p>Conclusion</p> <p>BAT is a useful tool for better selection of allergen for immunotherapy, for identification of patients prone to side effects and patients who might be treatment failures. However, long term studies are needed to evaluate the accuracy of the test.</p
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