15,331 research outputs found

    Understanding cellular internalization pathways of silicon nanowires

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    BACKGROUND: Understanding how cells interact with nanomaterials is important for rational design of nanomaterials for nanomedicine and transforming them for clinical applications. Particularly, the mechanism for one-dimensional (1D) nanomaterials with high aspect ratios still remains unclear. RESULTS: In this work, we present amine-functionalized silicon nanowires (SiNW-NH2) entering CHO-ÎČ cells via a physical membrane wrapping mechanism. By utilizing optical microscopy, transmission electron microscopy, and confocal fluorescence microscopy, we successfully visualized the key steps of internalization of SiNW-NH2 into cells. CONCLUSION: Our results provide insight into the interaction between 1D nanomaterials and confirm that these materials can be used for understanding membrane mechanics through physical stress exerted on the membrane

    Energy Transfer in CdSe Nanoplatelet Superlattices

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    Two-dimension CdSe semiconductor nanoplatelets (NPLs) exhibit unique, highly desirable optical and electronic properties, such as large absorption crossection and bright emission. FÓ§rster resonance energy transfer (FRET) between NPLs is responsible for the utility of these NPLs in fields such as lasing, lighting, solar energy, and sensing. Here we study energy transfer processes in NPL superlattices using photoluminescence (PL) and time resolved PL (TRPL) spectroscopic methods. Information on the effect of thickness of NPL is obtained through correlating PL and TRPL spectra of CdSe superlattices with AFM measurements. PL spectrum showed narrow fluorescence and absorption peaks at room temperature corresponding to excitonic transitions. A FRET lifetime of 351 ps was observed. Results suggest that FRET occurs more rapidly in CdSe NPL superlattices than in isolated CdSe NPLs and that FRET lifetimes depend on available energy pathways in the surrounding environment. This is a promising new material in the field of semiconductors and optical applications

    The Information Asymmetry between Management and Rank-and-File Employees: Determinants and Consequences

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    We investigate whether information possessed by rank-and-file employees is incorporated in top managers’ expectations and decisions. Using employees’ predictions of their company’s business outlook from Glassdoor.com to measure the employees’ information set, and using management earnings forecasts to measure management expectations, we show that management expectations incorporate employees’ information only partially. This intrafirm information asymmetry is lower when top managers are more experienced and internally engaged and when employees are more satisfied with senior management, firm culture, and their compensation; and higher in companies that are more decentralized, have internal control weakness, and poorly incentivize their employees. Further analyses suggest that our results are not driven by managers’ strategically choosing not to use employees’ information in their forecasts. Finally, we document that firms with large discrepancies between management forecasts and employee outlook have poorer future performance and a higher likelihood of CEO turnover

    Keeping it Simple: Simplified Frameworks for Long-Lived Particles at Neutrino Facilities

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    Modern-day accelerator neutrino facilities are excellent venues for searches for new-physics particles. Many distinct new-physics models predict overlapping signatures and phenomenology in these experiments. In this work, we advocate for the adoption of simplified frameworks when studying these types of new-physics signatures, which are characterized by a small number of primary variables, including particle masses, lifetimes, and production and decay modes/rates that most directly control signal event rates and kinematics. In particular, taking the example of long-lived particles that decay inside a neutrino detector as a test case, we study formulate and study simplified frameworks in the context of light scalars/fermions produced in kaon decays which then decay into final states containing an electron-positron pair. We show that using these simplified frameworks can allow for individual experimental analyses to be applicable to a wide variety of specific model scenarios. As a side benefit, we demonstrate that using this approach can allow for the T2K collaboration, by reinterpreting its search for Heavy Neutral Leptons, to be capable of setting world-leading limits on the Higgs-Portal Scalar model. Furthermore, we argue the simplified framework interpretation can serve as a bridge to model identification in the hopeful detection of a new-physics signal. As an illustration, we perform a first determination of the likelihood that, in the presence of a new-physics signal in a detector like the DUNE ND-GAr, multiple different new-physics hypotheses (such as the Higgs-Portal Scalar and Heavy Neutral Lepton ones) can be disentangled. We demonstrate that this model discrimination is favorable for some portions of detectable new-physics parameter space but for others, it is more challenging.Comment: 22 pages, 10 figures. Updated to JHEP versio

    Survey of vector-borne agents in feral cats and first report of Babesia gibsoni in cats on St Kitts, West Indies

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    Background: As there is little data on vector-borne diseases of cats in the Caribbean region and even around the world, we tested feral cats from St Kitts by PCR to detect infections with Babesia, Ehrlichia and spotted fever group Rickettsia (SFGR) and surveyed them for antibodies to Rickettsia rickettsii and Ehrlichia canis. Results: Whole blood was collected from apparently healthy feral cats during spay/ neuter campaigns on St Kitts in 2011 (N = 68) and 2014 (N = 52). Sera from the 52 cats from 2014 were used to detect antibodies to Ehrlichia canis and Rickettsia rickettsii using indirect fluorescent antibody tests and DNA extracted from whole blood of a total of 119 cats (68 from 2011, and 51 from 2014) was used for PCRs for Babesia, Ehrlichia and Rickettsia. We could not amplify DNA of SFG Rickettsia in any of the samples but found DNA of E. canis in 5% (6/119), Babesia vogeli in 13% (15/119), Babesia gibsoni in 4% (5/119), mixed infections with B. gibsoni and B. vogeli in 3% (3/119), and a poorly characterized Babesia sp. in 1% (1/119). Overall, 10% of the 52 cats we tested by IFA for E. canis were positive while 42% we tested by indirect fluorescent antibody (IFA) for R. rickettsii antigens were positive. Conclusions: Our study provides the first evidence that cats can be infected with B. gibsoni and also indicates that cats in the Caribbean may be commonly exposed to other vector-borne agents including SFGR, E. canis and B. vogeli. Animal health workers should be alerted to the possibility of clinical infections in their patients while public health workers should be alerted to the possibility that zoonotic SFGR are likely circulating in the region

    Seasonal Variations of Sea Surface Height in the Gulf Stream Region*

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    A systematic review of empirical methods for modelling sectoral carbon emissions in China

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    © 2019 Elsevier Ltd A number of empirical methods have been developed to study China's sectoral carbon emissions (CSCE). Measuring these emissions is important for climate change mitigation. While several articles have reviewed specific methods, few attempts conduct a systematic analysis of all the major research methods. In total 807 papers were published on CSCE research between 1997 and 2017. The primary source of literature for this analysis was taken from the Web of Science database. Based on a bibliometric analysis using knowledge mapping with the software CiteSpace, the review identified five common families of methods: 1) environmentally-extended input-output analysis (EE-IOA), 2) index decomposition analysis (IDA), 3) econometrics, 4) carbon emission control efficiency evaluation and 5) simulation. The research revealed the main trends in each family of methods and has visualized this research into ten research clusters. In addition, the paper provides a direct comparison of all methods. The research results can help scholars quickly identify and compare different methods for addressing specific research questions

    Fall Risk Reduction Using Lifestyle-integrated Functional Exercise (LiFE)

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    As the population and longevity of older adults’ increases, the prevalence of falls is becoming an ever-growing issue. One in three adults aged 65 years and older experience a fall each year. Falls in older adults may lead to sedentary behavior, decreased independence, and lower quality of life. Evidence has shown that traditional exercise programs emphasizing strength and balance exercises can decrease the fall risk in older adults, but may be difficult to sustain over time. Emerging evidence suggests that exercises that are integrated into daily life may have a more lasting effect in reducing fall risk in older adults. This study explored the effectiveness of an integrated exercise program, the modified-LiFE program, in decreasing fall risk in community-dwelling older adults. Results supported integrative exercise programs may decrease fall risk in community-dwelling older adults with previous history of falls. Therefore, integrating exercises into daily life offers occupational therapists an effective occupation-based intervention that promotes safety, independence, and quality of life for older adults.https://scholar.dominican.edu/ug-student-posters/1021/thumbnail.jp

    Differences in duration of untreated psychosis for racial and ethnic minority groups with first-episode psychosis: an updated systematic review and meta-analysis.

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    PURPOSE: Ethnic minority groups with early psychosis may have longer treatment delays, potentially leading to poorer outcomes. We updated a previous systematic review of the literature on racial and ethnic differences in duration of untreated psychosis (DUP) among people with first-episode psychosis. RESULTS: Six of 17 studies described significant differences across aggregated racial groups; however, the pooled estimates did not show differences across groups. Additional data from this update allowed for disaggregated analyses, finding that Black-African groups have a shorter DUP, whereas Black-Caribbean groups have longer DUP, relative to White groups. CONCLUSIONS: These findings highlight the importance of in-depth research on disaggregated ethnic groups to inform targeted early intervention strategies for minority populations
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