The prevalence of AGN feedback in massive galaxies at z~1

We use the optical--infrared imaging in the UKIDSS Ultra Deep Survey field, in combination with the new deep radio map of Arumugam et al., to calculate the distribution of radio luminosities among galaxies as a function of stellar mass in two redshift bins across the interval 0.4<z<1.2. This is done with the use of a new Bayesian method to classify stars and galaxies in surveys with multi-band photometry, and to derive photometric redshifts and stellar masses for those galaxies. We compare the distribution to that observed locally and find agreement if we consider only objects believed to be weak-lined radio-loud galaxies. Since the local distribution is believed to be the result of an energy balance between radiative cooling of the gaseous halo and mechanical AGN heating, we infer that this balance was also present as long ago as z~1. This supports the existence of a direct link between the presence of a low-luminosity ('hot-mode') radio-loud active galactic nucleus and the absence of ongoing star formation.Comment: 10 pages, MNRAS, in pres

Final Project Report: Glucose Monitoring Group

Retroreflectors can potentially be used in the design of a minimally invasive glucose-monitoring device. The primary objective of this senior design project is to design, build, and test a system to show that retroreflectors can be detected through a semi-opaque medium similar to human tissue. The secondary objective is to determine if the system can detect the retroreflectors through blood with and without gold nanoparticles. The design constraints of the project are described as well as the design of the apparatus, the test setup and procedure protocols for the project, the results of these tests, and a conceptual design. Data from the test procedure is collected by using a HeNe laser that shines through one converging lenses, an iris, a beam splitter, a semi-opaque medium to emulate human tissue, and gold nanoparticles that mimic glucose molecules in blood. The light hits a retroreflector that sends the light back through the beam splitter to a photodiode that is hooked up to a digital multimeter to measure the detected signal. A full factorial two factor Design of Experiments (DOE) with three levels is used to test the apparatus. Nanoparticle concentration and angle of incidence on the retroreflector are the dependent variables. The DOE is run two times for the water medium, but the testing of semi-opaque media are unable to be performed due to scattering of the beam. In deionized water, minimal interaction effects between nanoparticle concentration and angle are observed, and light scattering appears to increase as nanoparticle concentration increases. In blood, significant interaction effects are observed, and light scattering appears to decrease as nanoparticle concentration increases. This unexpected trend is likely due to unforeseen interactions between the nanoparticles and the solutes in blood. It is concluded that the apparatus is sufficient to provide results for the water medium, and insufficient for more opaque media due to scattering. Altered nanoparticles are needed for testing in blood

Measurement invariance of the parent-reported Strengths and Difficulties Questionnaire in autistic adolescents

Autistic people are more likely than non-autistic people to experience mental health difficulties. The Strengths and Difficulties Questionnaire is often used to screen for these difficulties and to otherwise make important decisions about mental health treatment and research in populations of autistic people. However, this study suggests that parent-reported Strengths and Difficulties Questionnaire scores may not be useful for comparing autistic and non-autistic adolescents at 11, 14 and 17 years old, as well as screening for mental health conditions in autistic adolescents. In addition, several items may be more likely to be endorsed by parents of autistic 17-year-olds than by parents of non-autistic 17-year-olds (and vice versa), which might suggest caution is needed when comparing groups on specific items

The political economy of reforming agricultural support policies

Agricultural support policies cost more than US$800 billion per year in transfers to the farm sector worldwide. Support policies based on subsidies and trade barriers are highly distortive to markets and are also regressive as most support is provided to larger farmers. On balance, the incentives this support creates appear to increase greenhouse gas emissions that contribute to climate change. In addition, some subsidies undermine the production of more nutrient-dense commodities that are otherwise critical for the improvement of dietary outcomes. This paper first highlights that better outcomes could be achieved if even a small portion of agricultural subsidies were repurposed into investments in research and development (R&D) dedicated to productivity-enhancing and emission-reducing technologies. This would create multiple wins — mitigating global climate change, reducing poverty, increasing food security, and improving nutrition. Nonetheless, the political economy challenges to doing so are sizeable. Because current support policies are often politically popular and serve well-organized interests, reform is difficult without committed political leadership and multilateral collaboration. Using several case studies of both successful and failed changes of agricultural support policies in China, India, and the EU and the United States, we highlight lessons learned about the political economy constraints on and possibilities for reform

Fabrication of a Lightweight CTE Matched Optical Structure from Be-Beo Metal Matrix Composite

To enable new discoveries in astrophysics by building lightweight high angular resolution X-ray optics. Goal is to achieve high resolution of Chandra with mass/cost of Suzaku