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This study examined whether musical training, ethnicity, and experience with a natural tone language influenced sensitivity to tone while listening to an artificial tone language. The language was designed with three tones, modeled after level-tone African languages. Participants listened to a 15-min random concatenation of six 3-syllable words. Sensitivity to tone was assessed using minimal pairs differing only in one syllable (nonword task: e.g., to-kà-su compared to ca-fí-to) or only in tone (tone task: e.g., to-kà-su compared to to-ká-su). Proficiency in an East Asian heritage language was the strongest predictor of success on the tone task. Asians without tone language experience were no better than other ethnic groups. We conclude by considering implications for research on second language learning, especially as approached through artificial language learning.
The Kepler Mission was designed to measure the frequency of Earth-like planets in the habitable zone of Sun-like stars. A requirement for determining the underlying planet population from a sample of detected planets is understanding the completeness of that sample—what fraction of the planets that could have been discovered in a given data set were actually detected. Here we describe an experiment designed to address a specific aspect of that question, which is the issue of signal throughput efficiency. We investigate the extent to which the Kepler pipeline preserves transit signals by injecting simulated transit signals into the pixel-level data, processing the modified pixels through the pipeline, and measuring their detection statistics. For the single channel that we examine initially, we inject simulated transit signal trains into the pixel time series of each of the 1801 targets for the 89 days that constitute Quarter 3. For the 1680 that behave as expected in the pipeline, on average we find the strength of the injected signal is recovered at 99.6% of the strength of the original signal. Finally we outline the further work required to characterise the completeness of the Kepler pipeline.
Intercropping is a common practice in Africa, but the advantage compared to sole cropping depends on the crop plants and local agro-ecological conditions. The potential of intercropping maize (Zea mays) or sorghum (Sorghum bicolor) with watermelon (Citrullus lanatus) was tested in two on-farm trials in southern Mozambique under semi-arid conditions in an area with low and unpredictable rainfall. In the first experiment, plant density, yield and monetary value of sole and intercropping plots of maize with watermelon were determined in 17 farmers' fields in an area where all crops developed to maturity and harvest. There was a significant reduction in yield of both maize (28.8%) and watermelon (57.8%) in the intercrop compared with the sole crop yields. However, the mean land equivalent ratio of 1.13 for yield showed that intercropping had advantages as, on average, an area planted with sole crops would require 13% more land than an intercrop production to generate the same outcome. In the second experiment, carried out in another area with 16 farmers' fields, drought was more pronounced and only watermelon developed to maturity. Intercroppings with maize and sorghum resulted in 70% and 69% yield reduction, respectively. In conclusion, watermelon is a good companion crop for intercropping with cereals to mitigate the risk of total crop failure due to drought.
On-farm yield experiments were carried out in the Tombouctou region of Mali in 2009/10 under heat- and drought-prone desert conditions with three local landraces of seed-type watermelons. The landraces, named Fombou, Kaneye and Musa Musa by the farmers, exhibited distinct characteristics for fruit morphology, but in particular for seed traits. On average, the three landraces produced a fruit yield of 11·6 t/ha and an estimated seed yield of 364 kg/ha, with no significant differences among landraces. Kaneye showed the highest stability of fruit number/ha in different field environments, suggesting this landrace is the best among the three for a poor growing environment, whereas Fombou and especially Musa Musa responded positively to more favourable environments. Seed weight revealed a different trend, with Fombou as the most responsive to favourable conditions, while Kaneye and Musa Musa were less responsive. The yields obtained suggest that these local landraces of watermelon are valuable plant genetic resources for securing food supply in arid, heat- and drought-prone areas.
There is a lack of specific knowledge about the dose–response effect of multiple parental risk factors for suicide attempts among children and adolescents. The aim of this study was to determine the dose–response effect of multiple parental risk factors on an offspring's risk for suicide attempt.
Method
We designed a population-based two-generation nested case–control study and used Danish register data. A population of 403 431 individuals born between 1983 and 1989 was sampled. Among these, 3465 (0.8%) were registered as having had a suicide attempt. Twenty controls were matched to each case and a link to the offspring's biological parents was established.
Results
There was a dose–response relationship between the number of exposures and the risk of suicide attempts, with the increased risk seeming to be a multiplicative effect. Parental suicide, suicide attempt, psychiatric illness and low level of income were all significant independent risk factors for offspring's suicide attempts.
Conclusions
Knowledge of the effect of multiple risk factors on the likelihood of suicide attempts in children and adolescents is important for risk assessment. Dose–response effects of multiple parental risk factors are multiplicative, but it is rare for children and adolescents to be exposed to multiple parental risk factors simultaneously. Nevertheless, they should be considered along with the offspring's own multiple risk factors in determining the overall risk of a suicide attempt. Further research incorporating both parental and offspring's risk factors is indicated to determine the overall dose–response effect of multiple risk factors.
To describe an outbreak of invasive methicillin-resistant Staphylococcus aureus (MRSA) infection after percutaneous needle procedures (acupuncture and joint injection) performed by a single medical practitioner.
Setting.
A medical practitioner's office and 4 hospitals in Perth, Western Australia.
Patients.
Eight individuals who developed invasive MRSA infection after acupuncture or joint injection performed by the medical practitioner.
Methods.
We performed a prospective and retrospective outbreak investigation, including MRSA colonization surveillance, environmental sampling for MRSA, and detailed molecular typing of MRSA isolates. We performed an infection control audit of the medical practitioner's premises and practices and administered MRSA decolonization therapy to the medical practitioner.
Results.
Eight cases of invasive MRSA infection were identified. Seven cases occurred as a cluster in May 2004; another case (identified retrospectively) occurred approximately 15 months earlier in February 2003. The primary sites of infection were the neck, shoulder, lower back, and hip: 5 patients had septic arthritis and bursitis, and 3 had pyomyositis; 3 patients had bacteremia, including 1 patient with possible endocarditis. The medical practitioner was found to be colonized with the same MRSA clone [ST22-MRSA-IV (EMRSA-15)] at 2 time points: shortly after the first case of infection in March 2003 and again in May 2004. After the medical practitioner's premises and practices were audited and he himself received MRSA decolonization therapy, no further cases were identified.
Conclusions.
This outbreak most likely resulted from a breakdown in sterile technique during percutaneous needle procedures, resulting in the transmission of MRSA from the medical practitioner to the patients. This report demonstrates the importance of surveillance and molecular typing in the identification and control of outbreaks of MRSA infection.
The NASA Discovery mission EPOXI, utilizing the Deep Impact flyby spacecraft, comprises two phases: EPOCh (Extrasolar Planet Observation and Characterization) and DIXI (Deep Impact eXtended Investigation). With EPOCh, we use the 30-cm high resolution visible imager to obtain ultraprecise photometric light curves of known transiting planet systems. We will analyze these data for evidence of additional planets, via transit timing variations or transits; for planetary moons or rings; for detection of secondary eclipses and the constraint of geometric planetary albedos; and for refinement of the system parameters. Over a period of four months, EPOCh observed four known transiting planet systems, with each system observed continuously for several weeks. Here we present an overview of EPOCh, including the spacecraft and science goals, and preliminary photometry results.
EPOXI (EPOCh + DIXI) is a NASA Discovery Program Mission of Opportunity using the Deep Impact flyby spacecraft. The EPOCh (Extrasolar Planet Observation and Characterization) Science Investigation will gather photometric time series of known transiting exoplanet systems from January through August 2008. Here we describe the steps in the photometric extraction of the time series and present preliminary results of the first four EPOCh targets.
The primary goal of the biomaterials scientist and tissue engineer is to create a biocompatible implant which mimics the mechanical and morphological properties of the tissue being replaced. In vitro experimentation has documented the propensity of soluble type I collagen to self-assemble and form microscopic collagen fibrils with periodic banding analogous to native collagen fiber. Our laboratory has further investigated in vitro self-assembly by incorporating several of the “natural” processes into a multi-step fiber formation procedure which generates macroscopic collagen fiber from its molecular constituents. Results of uniaxial tensile tests and ultrastructural analyses indicate that these coextruded and stretched collagen fibers have mechanical properties and fibrillar substructure comparable to that observed in native collagen fiber.
Collagen fibers self-assembled from solutions of molecular type I collagen were mineralized at pH 9.5, by exposure to super-saturated solutions of calcium and phosphate for a one week period in a double diffusion chamber. Uniaxial tensile mechanical properties increased with mineralization and electron microscopy of the mineral formed within the fiber was morphologically similar to the mineral phase of calcified tissues. Selected area electron diffraction confirms the presence of hydroxyapatite crystal. Further, the aligned fibrillar substructure serves as a template for the orientation of the c-axis diffraction maxima of the hydroxyapatite. These results indicate that an aligned system composed exclusively of selfassembled type I collagen fibrils serves as a scaffold for oriented growth of mineral analogous to calcification in vertebrate bone.
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