A Closer Look at Jamnitzer's Polyhedra

The Renaissance artist Wentzel Jamnitzer designed series of intriguing polyhedra in perspective in his book “Perspectiva Corporum Regularium”. In this paper we investigate the possible principles of the construction of the polyhedra and create 3D computer models of them. Comparing those to the originals, we get an idea of how successful he was in drawing the complex structures by imagination. Furthermore, we analyse Jamnitzer's use of linear perspective, an important key in creating such drawings

Does Offering More Science at School Increase the supply of Scientists? The Impact of Offering Triple Science at GCSE on subsequent Educational Choices and Outcomes.

I estimate the effects of an education policy (Triple Science) in England aimed at increasing the take-up and attainment of young people in science subjects. I identify the effect of the policy by comparing two adjacent cohorts of pupils in schools that offer Triple Science to one cohort, but not to the other. I find some large and significant effects on later subject choice and attainment, and these appear to be particularly strong for boys and pupils from more deprived backgrounds

Characterization of Human Prostate Cancer Using Sodium Magnetic Resonance Imaging

Overtreatment of prostate cancer is a significant problem in the health care of men. Development of non-invasive imaging tools for improved characterization of prostate lesions has the potential to reduce overtreatment. In this thesis work, we will evaluate the ability of tissue sodium concentration obtained from sodium magnetic resonance imaging (sodium-MRI) to characterize in vivo prostate lesions. Imaging data, including multi-parametric magnetic resonance imaging (mpMRI) and sodium-MRI, were obtained from a cohort of men with biopsy-proven prostate cancer and compared to digitized whole-mount histopathology after prostatectomy. Histopathology was independently graded for Gleason score to be used as the ground truth of tumour aggression. These imaging data were all accurately co-registered, allowing for direct comparison of imaging contrast to Gleason score. The results of this thesis work suggest that tissue sodium concentration assessed by sodium-MRI has utility as a part of a “non-invasive imaging-assay” to accurately characterize prostate cancer lesions. Sodium-MRI can provide clinically useful, complementary information to mpMRI; ultimately leading to better characterization of prostate lesions throughout the whole prostate. This has potential to improve patient outcomes of men with low-risk disease who do opt for active surveillance instead of treatment

Recent large increases in freshwater fluxes from Greenland into the North Atlantic

[1] Freshwater (FW) fluxes from river runoff and precipitation minus evaporation for the pan Arctic seas are relatively well documented and prescribed in ocean GCMs. Fluxes from Greenland on the other hand are generally ignored altogether, despite their potential impacts on ocean circulation and marine biology. Here, we present a reconstruction of the spatially distributed FW flux from Greenland for 1958–2010. We find a modest increase into the Arctic Ocean during this period. Fluxes into the Irminger Basin, however, have increased by fifty percent (6.3 ± 0.5 km3 yr−2) in less than twenty years. This greatly exceeds previous estimates. For the ice sheet as a whole the rate of increase since 1992 is 16.9 ± 1.8 km3 yr−2. The cumulative FW anomaly since 1995 is 3200 ± 358 km3, which is about a third of the magnitude of the Great Salinity Anomaly (GSA) of the 1970s. If this trend continues into the future, the anomaly will exceed that of the GSA by about 2025

'Wees zuinig op vruchtbare grond'

In Zuid-Europa neemt de hoeveelheid organische stof in de grond af en dreigt verwoestijning. Noordwest-Europese landen kennen weer andere bodembedreigingen. ‘Europa moet zuinig zijn op haar goede landbouwgronden’, meent Mirjam Hack, onderzoeker bij Alterra

Seasonally and Diurnally Varying Cold Front Effects along the Minnesotan North Shore of Lake Superior

Cold fronts are typically associated with cooling, drying and a strengthening wind that shifts to have a northerly component. Cold front effects at a particular point, however, are dependent upon pre-existing air mass characteristics. Here, we examine 634 passages of synoptic-scale cold fronts in northeastern Minnesota from 2010 to 2018. While these fronts are associated with the expected effects in some areas, they are often associated with warming and enhanced drying in the region directly influenced by an air mass from Lake Superior (coastal sites). Coastal sites experience warming during more than half of cold frontal passages, in contrast to proximate inland sites out of the influence of the lake. This warming, combined with a removal of the moist lake air mass, often leads to a sharp post-front decrease in relative humidity. These relatively unusual local effects indicate a need to carefully consider characteristics of the lake air mass and likely changes during cold frontal passage when forecasting regional temperature and fire weather conditions

Bioscatter transport by tropical cyclones: insights from 10 years in the Atlantic basin

Tropical cyclones (TCs) can transport birds and insects near their center of circulation. In this study, we examined the maximum altitude, area and density of the radar-derived bioscatter signature across a set of 42 TC centers of circulation sampled from 2011 to 2020. All TC events contained at least one time when a bioscatter signature was present. More intense hurricanes with closed eyes typically had taller and denser bioscatter signatures, and sometimes larger areas dominated by bioscatter. This indicated a larger number of organisms within the circulation of more intense hurricanes, supporting the speculation that those storms were most likely to trap birds that do not want to risk flying through their eyewall thunderstorms. Larger and denser bioscatter signatures, indicating a larger number of birds, tend to occur when fall migration brings a large bird population to the Gulf and East Coasts where most storms were sampled. TC formation location was not related to bioscatter characteristics, but storms sampled in the Gulf of Mexico and Florida tended to have larger and denser bioscatter signatures

Radar quantification, temporal analysis and influence of atmospheric conditions on a roost of American Robins (\u3ci\u3eTurdus migratorius\u3c/i\u3e) in Oklahoma

Radar observations present a way to monitor large, mobile populations across long temporal scales, and are especially valuable when individual scatterers are challenging to count visually. The focus of this study is a large and relatively homogeneous wintertime roost of American Robins (Turdus migratorius) in central Oklahoma. Radar observations are used to estimate the roost population through winter 2010–2011, and the population time series is related to weather variables and radar beam propagation. Radar-estimated roost population gradually increased to an estimated peak of 1.5–2 million individuals from November 2010 to January 2011, and then decreased in a more stepwise manner through the spring until roost dispersal in early March. Weather conditions did not definitively explain these population decreases leading toward roost dispersal. Birds from the roost were often observed to travel \u3e50 km away during the daytime. About 25–30% of the variability in the radar-derived roost population estimate could be explained by atmospheric variables. This work provides an example of how radar methods may be used to estimate populations and monitor their temporal trends, which may be valuable to conservation efforts by facilitating estimates of population change through time