460 research outputs found

    Communication in Crisis

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    The communication of messages of the impending impact of some natural disaster agent can play a key role in averting natural catastrophe. This article examines the social processes involved in disaster warnings which function to elicit evacuation in such threat situations. These processes and the role of the mass media in forming situational definitions requisite for evacuation are examined in reference to data gathered in Rapid City, South Dakota where on June 9, 1972 a flash flood produced a major disaster.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68175/2/10.1177_009365027500200102.pd

    Exploring barriers to consistent condom use among sub-Saharan African young immigrants in Switzerland.

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    No study to date has focused on barriers to condom use specifically among young immigrants to Europe from sub-Saharan Africa. Based on a qualitative study in sociology, this paper explores generational differences in barriers to condom use between first-generation immigrants (born in Africa and arrived in Switzerland after age 10) and second-generation immigrants (born in Switzerland to two native parents or arrived in Switzerland before age 10). Results are based on in-depth, semistructured individual interviews conducted with 47 young women and men aged 18 to 25 to understand how individual, relational, and cultural dimensions influence sexual socialization and practices. Six main barriers to consistent condom use were identified: reduced pleasure perception, commitment and trust, family-transmitted sexual norms and parental control, lack of accurate knowledge on HIV transmission, lack of awareness about HIV in Switzerland, and gender inequalities. The three first barriers concerned both generations of immigrants, whereas the three last revealed generational differences. These findings can help sexual health providers identify social causes for young sub-Saharan immigrants not using condoms. The findings also highlight the necessity of offering accurate, accessible, and adapted information to all young immigrants, as well as the particular importance of addressing families' lack of discussions about sex, understanding the sexual norms transmitted by parents, and taking into consideration cultural differences among young people born in immigration countries

    Cwatset Isomorphism and its Consequences

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    We explore the consequences of cwatset isomorphism (there are a finite number of non-isomorphic cwatsets of each order) and consider parallels between the theory of groups and the theory of cwatsets (cwatsets of prime order are cyclic but direct sums of isomorphic cwatsets aren\u27t necessarily isomorphic)

    AC Stark-shift in CPT-based Cs miniature atomic clocks

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    We report on studies on the light-shift in caesium miniature atomic clocks based on coherent population trapping (CPT) using a micro-fabricated buffer-gas cell (MEMS cell). The CPT signal is observed on the Cs D1-line by coupling the two hyperfine ground-state Zeeman sublevels involved in the clock transition to a common excited state, using two coherent electromagnetic fields. These light fields are created with a distributed feedback laser and an electro-optical modulator. We study the light-shift phenomena at different cell temperatures and laser wavelengths around 894.6nm. By adjusting the cell temperature, conditions are identified where a miniature CPT atomic clock can be operated with simultaneously low temperature coefficient and suppressed light-shift. The impact of the light-shift on the clock frequency stability is evaluated. These results are relevant for improving the long-term frequency stability of CPT-based Cs vapour-cell clock

    Quadratic dependence on temperature of Cs 0-0 hyperfine resonance frequency in single Ne buffer gas microfabricated vapour cell

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    Presented is the observation of a quadratic temperature dependence of the Cs 0-0 ground state hyperfine resonance frequency in a single Neon (Ne) buffer gas vapour microcell. The inversion temperature, expected to be theoretically independent of the buffer gas pressure, is measured to be about 80-C for two different samples. A proposal to develop chip scale atomic clocks with improved long-term frequency stability, simpler configuration (a single buffer gas instead of a buffer gas mixture) and then relaxed constraints on pressure accuracy during the cell filling procedure is presented

    Comparison of the immunomodulatory properties of three probiotic strains of Lactobacilli using complex culture systems: prediction for in vivo efficacy

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    Background: While the use of probiotics to treat or prevent inflammatory bowel disease (IBD) has been proposed, to this point the clinical benefits have been limited. In this report we analyzed the immunological activity of three strains of Lactobacillus to predict their in vivo efficacy in protecting against experimental colitis. Methodology/Principal Findings: We compared the immunological properties of Lactobacillus plantarum NCIMB8826, L. rhamnosus GG (LGG), L. paracasei B21060 and pathogenic Salmonella typhimurium (SL1344). We studied the stimulatory effects of these different strains upon dendritic cells (DCs) either directly by co-culture or indirectly via conditioning of an epithelial intermediary. Furthermore, we characterized the effects of these strains in vivo using a Dextran sulphate sodium (DSS) model of colitis. We found that the three strains exhibited different abilities to induce inflammatory cytokine production by DCs with L. plantarum being the most effective followed by LGG and L. paracasei. L. paracasei minimally induced the release of cytokines, while it also inhibited the potential of DCs to both produce inflammatory cytokines (IL-12 and TNF-\u3b1) and to drive Th1 T cells in response to Salmonella. This effect on DCs was found under both direct and indirect stimulatory conditions - i.e. mediated by epithelial cells - and was dependent upon an as yet unidentified soluble mediator. When tested in vivo, L. plantarum and LGG exacerbated the development of DSS-induced colitis and caused the death of treated mice, while, conversely L. paracasei was protective. Conclusions: We describe a new property of probiotics to either directly or indirectly inhibit DC activation by inflammatory bacteria. Moreover, some immunostimulatory probiotics not only failed to protect against colitis, they actually amplified the disease progression. In conclusion, caution must be exercised when choosing a probiotic strain to treat IBD

    Optical Clocks in Space

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    The performance of optical clocks has strongly progressed in recent years, and accuracies and instabilities of 1 part in 10^18 are expected in the near future. The operation of optical clocks in space provides new scientific and technological opportunities. In particular, an earth-orbiting satellite containing an ensemble of optical clocks would allow a precision measurement of the gravitational redshift, navigation with improved precision, mapping of the earth's gravitational potential by relativistic geodesy, and comparisons between ground clocks.Comment: Proc. III International Conference on Particle and Fundamental Physics in Space (SpacePart06), Beijing 19 - 21 April 2006, to appear in Nucl. Phys.

    Helicobacter pylori primary and secondary genotypic resistance to clarithromycin and levofloxacin detection in stools: A 4-year scenario in Southern Italy

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    Antibiotic resistance has become an emerging problem for treating Helicobacter pylori (H. pylori) infection. Clarithromycin and levofloxacin are two key antibiotics used for its eradication. Therefore, we reviewed our experience with genotypic resistance analysis in stools to both clarithromycin and levofloxacin in the last four years to evaluate time trends, both in naive and failure patients. Patients collected a fecal sample using the THD fecal test device. Real-time polymerase chain reaction was performed to detect point mutations conferring resistance to clarithromycin (A2142C, A2142G, and A2143G in 23S rRNA) and levofloxacin (substitutions at amino acid position 87 and 91 of gyrA). One hundred and thirty-five naive patients were recruited between 2017-2020. Clarithromycin resistance was detected in 37 (27.4%). The time trend did not show any significant variation from 2017 to 2020 (p = 0.33). Primary levofloxacin resistance was found in 26 subjects (19.2%), and we observed a dramatic increase in rates from 2017 (10%) to 2018 (3.3%), 2019 (20%), and 2020 (37.8%). Ninety-one patients with at least one eradication failure were recruited. Secondary resistance to clarithromycin and levofloxacin was found in 59 (64.8%) and 45 patients (59.3%), respectively. In conclusion, our geographic area has a high risk of resistance to clarithromycin. There is also a progressive spreading of levofloxacin-resistant strains

    New miniaturized microwave cavity for Rubidium atomic clocks

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    Nowadays there is an increasing need for radically miniaturized and low-power atomic frequency standards, for use in mobile and battery-powered applications. For the miniaturization of double-resonance (DR) Rubidium (Rb-87) atomic clocks, the size reduction of the microwave cavity or resonator (MWR) to well below the wavelength of the atomic transition (6.835 GHz for Rb-87) has been a long-standing issue. Here we present a newly developed miniaturized MWR, the mu-LGR, consisting of a loop-gap resonator based cavity with very compact dimensions (volume < 0.9 cm(3)). The mu-LGR meets the requirements of the atomic clock application and its assembly can be performed using repeatable and low-cost techniques. The concept of the proposed device was validated through simulations and prototypes were successfully manufactured and tested. High-quality DR spectra and first clock stabilities were demonstrated experimentally, proving that the mu-LGR is suitable for integration in a miniaturized atomic clock
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