579 research outputs found

    Collabor8: (Re-) Engaging female secondary cohorts in STEM subjects

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    Demand for skilled professionals in science, technology, engineering and mathematics (STEM) is projected to increase significantly with 75% of the fastest growing occupations requiring STEM skills (Australian Industry Group, 2013). Yet, over the past 20 years, Australia has seen significant decline in the number of secondary students - particularly girls - electing to study science and advanced mathematics (Office of Chief Scientist, 2014). A 2014 national STEM strategy from the Office of the Chief Scientist recommended support for `high levels of participation and success in STEM [education] for all Australians, including women, Indigenous students and students from disadvantaged and marginalised backgrounds’. Recent research builds on previous work (e.g. Fine et al, 2010; Lyons et al, 2012; Sikora, 2012; Mills et al, 2010). Zecharia et al identify three key factors found to be influencing young women’s participation in STEM subjects: 1. Relevance of STEM to sense of identity and future aspirations. 2. Perceived actual and relative ability in STEM subjects. 3. ‘Science capital’ - or experience of STEM, including formal and informal exposure to STEM subjects and careers through the curriculum, schooling, media, culture, family and personal connections’ (Zecharia et al., 2014 p.9). This paper introduces Collabor8, an engineering and IT outreach program for junior female students from high schools serving low socio-economic communities. Collabor8 will test the relative importance of Zecharia et al’s three key factors for participants’ interest in STEM; intention to select STEM subjects in senior high school and tertiary study, and evaluate the chosen outreach model

    A Prospective Study of the Association of Metacognitive Beliefs and Processes with Persistent Emotional Distress After Diagnosis of Cancer

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    Two hundred and six patients, diagnosed with primary breast or prostate cancer completed self-report questionnaires on two occasions: before treatment (T1) and 12 months later (T2). The questionnaires included: the Hospital Anxiety and Depression Scale; Impact of Events Scale; the Metacognitions Questionnaire-30 (MCQ-30) and the Illness Perceptions Questionnaire-revised. A series of regression analyses indicated that metacognitive beliefs at T1 predicted between 14 and 19 % of the variance in symptoms of anxiety, depression and trauma at T2 after controlling for age and gender. For all three outcomes, the MCQ-30 subscale ‘negative beliefs about worry’ made the largest individual contribution with ‘cognitive confidence’ also contributing in each case. For anxiety, a third metacognitive variable, ‘positive beliefs about worry’ also predicted variance in T2 symptoms. In addition, hierarchical analyses indicated that metacognitive beliefs explained a small but significant amount of variance in T2 anxiety (2 %) and T2 depression (4 %) over and above that explained by demographic variables, T1 symptoms and T1 illness perceptions. The findings suggest that modifying metacognitive beliefs and processes has the potential to alleviate distress associated with cancer

    A highly magnified candidate for a young galaxy seen when the Universe was 500 Myrs old

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    The early Universe at redshift z\sim6-11 marks the reionization of the intergalactic medium, following the formation of the first generation of stars. However, those young galaxies at a cosmic age of \lesssim 500 million years (Myr, at z \gtrsim 10) remain largely unexplored as they are at or beyond the sensitivity limits of current large telescopes. Gravitational lensing by galaxy clusters enables the detection of high-redshift galaxies that are fainter than what otherwise could be found in the deepest images of the sky. We report the discovery of an object found in the multi-band observations of the cluster MACS1149+22 that has a high probability of being a gravitationally magnified object from the early universe. The object is firmly detected (12 sigma) in the two reddest bands of HST/WFC3, and not detected below 1.2 {\mu}m, matching the characteristics of z\sim9 objects. We derive a robust photometric redshift of z = 9.6 \pm 0.2, corresponding to a cosmic age of 490 \pm 15Myr (i.e., 3.6% of the age of the Universe). The large number of bands used to derive the redshift estimate make it one of the most accurate estimates ever obtained for such a distant object. The significant magnification by cluster lensing (a factor of \sim15) allows us to analyze the object's ultra-violet and optical luminosity in its rest-frame, thus enabling us to constrain on its stellar mass, star-formation rate and age. If the galaxy is indeed at such a large redshift, then its age is less than 200 Myr (at the 95% confidence level), implying a formation redshift of zf \lesssim 14. The object is the first z>9 candidate that is bright enough for detailed spectroscopic studies with JWST, demonstrating the unique potential of galaxy cluster fields for finding highly magnified, intrinsically faint galaxies at the highest redshifts.Comment: Submitted to the Nature Journal. 39 Pages, 13 figure

    Classification and Identification of Bacteria by Mass Spectrometry and Computational Analysis

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    Background: In general, the definite determination of bacterial species is a tedious process and requires extensive manual labour. Novel technologies for bacterial detection and analysis can therefore help microbiologists in minimising their efforts in developing a number of microbiological applications. Methodology: We present a robust, standardized procedure for automated bacterial analysis that is based on the detection of patterns of protein masses by MALDI mass spectrometry. We particularly applied the approach for classifying and identifying strains in species of the genus Erwinia. Many species of this genus are associated with disastrous plant diseases such as fire blight. Using our experimental procedure, we created a general bacterial mass spectra database that currently contains 2800 entries of bacteria of different genera. This database will be steadily expanded. To support users with a feasible analytical method, we developed and tested comprehensive software tools that are demonstrated herein. Furthermore, to gain additional analytical accuracy and reliability in the analysis we used genotyping of single nucleotide polymorphisms by mass spectrometry to unambiguously determine closely related strains that are difficult to distinguish by only relying on protein mass pattern detection. Conclusions: With the method for bacterial analysis, we could identify fire blight pathogens from a variety of biological sources. The method can be used for a number of additional bacterial genera. Moreover, the mass spectrometry approac

    A two-step mechanism for epigenetic specification of centromere identity and function

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    The basic determinant of chromosome inheritance, the centromere, is specified in many eukaryotes by an epigenetic mark. Using gene targeting in human cells and fission yeast, chromatin containing the centromere-specific histone H3 variant CENP-A is demonstrated to be the epigenetic mark that acts through a two-step mechanism to identify, maintain and propagate centromere function indefinitely. Initially, centromere position is replicated and maintained by chromatin assembled with the centromere-targeting domain (CATD) of CENP-A substituted into H3. Subsequently, nucleation of kinetochore assembly onto CATD-containing chromatin is shown to require either the amino- or carboxy-terminal tail of CENP-A for recruitment of inner kinetochore proteins, including stabilizing CENP-B binding to human centromeres or direct recruitment of CENP-C, respectively.National Institutes of Health grant: (GM 074150); Ludwig Institute for Cancer Research; European Molecular Biology Organization (EMBO) long-term fellowship

    On becoming (un)committed: A taxonomy and test of newcomer on-boarding scenarios

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    How does the bond between the newcomer and the organization develop over time? Process research on temporal patterns of newcomer's early commitment formation has been very scarce because theory and appropriate longitudinal research designs in this area are lacking. From extant research we extract three process-theoretical accounts regarding how the newcomer adjustment process evolves over time: (1) Learning to Love; (2) Honeymoon Hangover; and (3) High Match, Moderate Match, or Low Match. From these scenarios we develop a taxonomy of newcomer adjustment scenarios. Further, we empirically verify these different scenarios by examining naturally occurring "trajectory classes," which are found to display strengthening, weakening, or stabilizing of the employee-organization linkage. For this, we use a sample of 72 Ph. D. graduates whose organizational commitment history was recorded in their first 25 consecutive weeks of new employment. In closing, we discuss the theoretical and practical implications of the scenario-based approach

    Heterogeneity of breast cancer risk within the South Asian female population in England: a population-based case–control study of first-generation migrants

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    South Asian women in England have a lower breast cancer risk than their English-native counterparts, but less is known about variations in risk between distinct South Asian ethnic subgroups. We used the data from a population-based case-control study of first-generation South Asian migrants to assess risks by ethnic subgroup. In all, 240 breast cancer cases, identified through cancer registries, were individually matched on age and general practitioner to two controls. Information on the region of origin, religious and linguistic background, and on breast cancer risk factors was obtained from participants. Breast cancer odds varied significantly between the ethnic subgroups (P=0.008), with risk increasing in the following order Bangladeshi Muslims (odds ratio (OR) 0.33, 95% confidence interval (CI): 0.10, 1.06), Punjabi Hindu (OR 0.59, 95% CI: 0.33, 1.27), Gujarati Hindu (I=reference group), Punjabi Sikh (OR 1.23, 95% CI: 0.72, 2.11) and Pakistani/Indian Muslims (OR 1.76, 95% CI: 1.10, 2.81). The statistically significant raised risk in Pakistani/Indian Muslims increased with adjustment for socioeconomic and reproductive risk factors (OR 2.12, 95% CI: 1.25, 3.58), but was attenuated, and no longer significant, with further adjustment for waist circumference and intake of nonstarch polysaccharides and fat (OR 1.49, 95% CI: 0.85, 2.63). These findings reveal differences in breast cancer risk between South Asian ethnic subgroups, which were not fully explained by reproductive differences, but were partly accounted for by diet and body size

    An approach for particle sinking velocity measurements in the 3–400 μm size range and considerations on the effect of temperature on sinking rates

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    The flux of organic particles below the mixed layer is one major pathway of carbon from the surface into the deep ocean. The magnitude of this export flux depends on two major processes—remineralization rates and sinking velocities. Here, we present an efficient method to measure sinking velocities of particles in the size range from approximately 3–400 μm by means of video microscopy (FlowCAM®). The method allows rapid measurement and automated analysis of mixed samples and was tested with polystyrene beads, different phytoplankton species, and sediment trap material. Sinking velocities of polystyrene beads were close to theoretical values calculated from Stokes’ Law. Sinking velocities of the investigated phytoplankton species were in reasonable agreement with published literature values and sinking velocities of material collected in sediment trap increased with particle size. Temperature had a strong effect on sinking velocities due to its influence on seawater viscosity and density. An increase in 9 °C led to a measured increase in sinking velocities of ~40 %. According to this temperature effect, an average temperature increase in 2 °C as projected for the sea surface by the end of this century could increase sinking velocities by about 6 % which might have feedbacks on carbon export into the deep ocean

    Contributions of nitrogen deposition and forest regrowth to terrestrial carbon uptake

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    <p>Abstract</p> <p>Background</p> <p>The amount of reactive nitrogen deposited on land has doubled globally and become at least five-times higher in Europe, Eastern United States, and South East Asia since 1860 mostly because of increases in fertilizer production and fossil fuel burning. Because vegetation growth in the Northern Hemisphere is typically nitrogen-limited, increased nitrogen deposition could have an attenuating effect on rising atmospheric CO<sub>2 </sub>by stimulating the vegetation productivity and accumulation of carbon in biomass.</p> <p>Results</p> <p>This study shows that elevated nitrogen deposition would not significantly enhance land carbon uptake unless we consider its effects on re-growing forests. Our results suggest that nitrogen enriched land ecosystems sequestered 0.62–2.33 PgC in the 1980s and 0.75–2.21 PgC in the 1990s depending on the proportion and age of re-growing forests. During these two decades land ecosystems are estimated to have absorbed 13–41% of carbon emitted by fossil fuel burning.</p> <p>Conclusion</p> <p>Although land ecosystems and especially forests with lifted nitrogen limitations have the potential to decelerate the rise of CO<sub>2 </sub>concentrations in the atmosphere, the effect is only significant over a limited period of time. The carbon uptake associated with forest re-growth and amplified by high nitrogen deposition will decrease as soon as the forests reach maturity. Therefore, assessments relying on carbon stored on land from enhanced atmospheric nitrogen deposition to balance fossil fuel emissions may be inaccurate.</p
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