Improvement and evaluation of simulated global biogenic soil NO emissions in an AC-GCM

Biogenic NO emissions from soils (SNOx) play important direct and indirect roles in tropospheric chemistry. The most widely applied algorithm to calculate SNOx in global models was published 15 years ago by Yienger and Levy (1995), and was based on very few measurements. Since then, numerous new measurements have been published, which we used to build up a compilation of world wide field measurements covering the period from 1978 to 2010. Recently, several satellite-based top-down approaches, which recalculated the different sources of NOx (fossil fuel, biomass burning, soil and lightning), have shown an underestimation of SNOx by the algorithm of Yienger and Levy (1995). Nevertheless, to our knowledge no general improvements of this algorithm, besides suggested scalings of the total source magnitude, have yet been published. Here we present major improvements to the algorithm, which should help to optimize the representation of SNOx in atmospheric-chemistry global climate models, without modifying the underlying principals or mathematical equations. The changes include: (1) using a new landcover map, with twice the number of landcover classes, and using annually varying fertilizer application rates; (2) adopting a fraction of 1.0 % for the applied fertilizer lost as NO, based on our compilation of measurements; (3) using the volumetric soil moisture to distinguish between the wet and dry states; and (4) adjusting the emission factors to reproduce the measured emissions in our compilation (based on either their geometric or arithmetic mean values). These steps lead to increased global annual SNOx, and our total above canopy SNOx source of 8.6 Tg yr−1 (using the geometric mean) ends up being close to one of the satellite-based top-down approaches (8.9 Tg yr−1). The above canopy SNOx source using the arithmetic mean is 27.6 Tg yr−1, which is higher than all previous estimates, but compares better with a regional top-down study in eastern China. This suggests that both top-down and bottom-up approaches will be needed in future attempts to provide a better calculation of SNOx

Exploring novel opportunities for molecular imaging in surgery:illuminating surgical decision making

Imaging modalities play a crucial role in surgical diagnosis and have the potential to deliver critical anatomical and biological information prior and during surgery. Fluorescence imaging is a novel technique which uses tumor-specific fluorescent tracers which give the opportunity to visualize tumor cells directly during surgery. This allows the surgeon to distinguish malignant from benign tissue in the operation room. In the first part of this thesis, we describe the use of fluorescence-guided surgery using novel tracers in a variety of solid tumors like soft tissue sarcomas, head- and neck cancer and breast cancer. We use intravenously administered fluorescent tracers to enhance tumor visualization. We show that this technique allows for an improved visualization of tumor-positive surgical margins and residual disease which were initially missed during surgery. These discoveries might improve surgical decision making directly during surgery which might lead to an improved patient outcome in the future. During vascular surgery, we try to track patients who are at risk for vascular stenosis which gives an increased risk in cerebral strokes. In the second part of this thesis we describe the use of a fluorescent tracer which is able to visualize the so-called vulnerable plaque. We show that it is possible to make an adequate distinction between a biological active and therefore vulnerable plaque and a non-vulnerable plaque. In the future, we are aiming for non-invasive imaging modalities using this technique to select patients prior to high-risk vascular interventions

Internet television use: Motivations and preferences for watching television online among college students

The present study examined the television viewing habits of college students to determine differences between motivations and preferences for watching television online versus on a broadcast receiver. A convenience sample of 136 RIT students responded to an online survey. The study found that like the TV viewers of the 1980s, television viewers today are still motivated by relaxation, escape, and the desire to pass the time and to socially interact with companions-- no matter which medium. The ability to control the television experience, to choose when to watch programming, and the convenience that Internet television offers are reasons why college students are using alternatives to the traditional broadcast receiver

THE EFFECTS OF PREGNANCY ON STUDENT PROGRESS

Ample evidence exists establishing the relationship between pregnancy during high school and subsequent educational difficulties, yet little research has investigated the relationship between pregnancy during college and subsequent educational difficulties. The purpose of this study was to determine if a relationship exists between pregnancy in undergraduate college students and educational attainment and to determine the strength and direction of said relationship. A quantitative research approach composed of historical medical and retention data was utilized. Vincent Tinto’s theory of student departure was applied to frame the use of experience of pregnancy diagnosis as a variable related to retention. Findings indicate a negative relationship between pregnancy diagnosis and educational retention, with specific ages and ethnicities at increased risk