330 research outputs found

    The Zero Initial in Chinese: A Preliminary Exploration into D2 and L2 Acquisition

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    The Chinese syllable traditionally consists of an initial and a final. If no overt consonant occupies the syllable-initial position, a zero initial (Ø) is placed there. This slot is often not empty, however, but contains a multitude of phonetic variants depending on such factors as (sub)dialectal differences and the phonetic properties of the following vowel. This small, preliminary study, making use of simple, visual inspection of waveforms and spectrograms in Praat, contributes to issues of facilitation and interference in D2 and L2 acquisition. The focus is on the zero initial before high vowels in the following three settings: within the Yue dialects (Zhongshan, standard Cantonese), across varieties of Chinese (Mandarin, Yue), and across languages (Chinese, English)

    Tone and Melody in Cantonese

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    Proceedings of the Thirteenth Annual Meeting of the Berkeley Linguistics Society (1987), pp. 26-3

    Timeliness of Nongovernmental versus Governmental Global Outbreak Communications

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    To compare the timeliness of nongovernmental and governmental communications of infectious disease outbreaks and evaluate trends for each over time, we investigated the time elapsed from the beginning of an outbreak to public reporting of the event. We found that governmental sources improved the timeliness of public reporting of infectious disease outbreaks during the study period

    Centimeter to decimeter hollow concretions and voids in Gale Crater sediments, Mars

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    Voids and hollow spheroids between ∼1 and 23 cm in diameter occur at several locations along the traverse of the Curiosity rover in Gale crater, Mars. These hollow spherical features are significantly different from anything observed in previous landed missions. The voids appear in dark-toned, rough-textured outcrops, most notably at Point Lake (sols 302-305) and Twin Cairns Island (sol 343). Point Lake displays both voids and cemented spheroids in close proximity; other locations show one or the other form. The spheroids have 1-4 mm thick walls and appear relatively dark-toned in all cases, some with a reddish hue. Only one hollow spheroid (Winnipesaukee, sol 653) was analyzed for composition, appearing mafic (Fe-rich), in contrast to the relatively felsic host rock. The interior surface of the spheroid appears to have a similar composition to the exterior with the possible exceptions of being more hydrated and slightly depleted in Fe and K. Origins of the spheroids as Martian tektites or volcanic bombs appear unlikely due to their hollow and relatively fragile nature and the absence of in-place clearly igneous rocks. A more likely explanation to both the voids and the hollow spheroids is reaction of reduced iron with oxidizing groundwater followed by some re-precipitation as cemented rind concretions at a chemical reaction front. Although some terrestrial concretion analogs are produced from a precursor siderite or pyrite, diagenetic minerals could also be direct precipitates for other terrestrial concretions. The Gale sediments differ from terrestrial sandstones in their high initial iron content, perhaps facilitating a higher occurrence of such diagenetic reactions

    Use of In Vivo and In Vitro Systems to Select Leishmania amazonensis Expressing Green Fluorescent Protein

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    Various Leishmania species were engineered with green fluorescent protein (GFP) using episomal vectors that encoded an antibiotic resistance gene, such as aminoglycoside geneticin sulphate (G418). Most reports of GFP-Leishmania have used the flagellated extracellular promastigote, the stage of parasite detected in the midgut of the sandfly vector; fewer studies have been performed with amastigotes, the stage of parasite detected in mammals. In this study, comparisons were made regarding the efficiency for in vitro G418 selection of GFP-Leishmania amazonensis promastigotes and amastigotes and the use of in vivo G418 selection. The GFP-promastigotes retained episomal plasmid for a prolonged period and G418 treatment was necessary and efficient for in vitro selection. In contrast, GFP-amastigotes showed low retention of the episomal plasmid in the absence of G418 selection and low sensitivity to antibiotics in vitro. The use of protocols for G418 selection using infected BALB/c mice also indicated low sensitivity to antibiotics against amastigotes in cutaneous lesions

    Small edifice features in Chryse Planitia, Mars: Assessment of a mud volcano hypothesis

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    Small edifice features that are less than a few kilometers in diameter and up to a few hundred meters in height are widely distributed in Chryse Planitia on Mars. They exhibit a broad range of morphological properties that are here classified as Type 1 (steep-sided cones typically with a summit crater), Type 2 (nearly flat features with single or multiple central/summit craters or cones) and Type 3 (nearly circular features in plan view, characterized by steep sides and a broadly flat summit area). Their origins have not been determined with certainty, but our study utilizing the High Resolution Imaging Science Experiment (HiRISE) images supports the interpretation of mud volcanism, based on the observed morphological characteristics of these small edifices and comparisons with terrestrial analogs. Additionally, hydrated minerals detected on these edifice features in data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), further support the mud volcano hypothesis. Injection features such as clastic mega-pipes and sand blow features may coexist with the mud volcanoes. Alternative mechanisms such as magmatic volcanism are not excluded, but they have less support from our remote sensing observations. Further confirmation or rejection of the mud volcano hypothesis will require in-situ investigation by landers or rovers

    Non-Adherence in Patients on Peritoneal Dialysis: A Systematic Review

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    Background: It has been increasingly recognized that non-adherence is an important factor that determines the outcome of peritoneal dialysis (PD) therapy. There is therefore a need to establish the levels of non-adherence to different aspects of the PD regimen (dialysis procedures, medications, and dietary/fluid restrictions). Methods: A systematic review of peer-reviewed literature was performed in PubMed, PsycINFO and CINAHL databases using PRISMA guidelines in May 2013. Publications on non-adherence in PD were selected by two reviewers independently according to predefined inclusion and exclusion criteria. Relevant data on patient characteristics, measures, rates and factors associated with non-adherence were extracted. The quality of studies was also evaluated independently by two reviewers according to a revised version of the Effective Public Health Practice Project assessment tool. Results: The search retrieved 204 studies, of which a total of 25 studies met inclusion criteria. Reported rates of nonadherence varied across studies: 2.6 1353% for dialysis exchanges, 3.9 1385% for medication, and 14.4 1367% for diet/fluid restrictions. Methodological differences in measurement and definition of non-adherence underlie the observed variation. Factors associated with non-adherence that showed a degree of consistency were mostly socio-demographical, such as age, employment status, ethnicity, sex, and time period on PD treatment. Conclusion: Non-adherence to different dimensions of the dialysis regimen appears to be prevalent in PD patients. There is a need for further, high-quality research to explore these factors in more detail, with the aim of informing intervention designs to facilitate adherence in this patient populatio
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