An Analysis of the Pricing of Traits in the U.S. Corn Seed Market

This paper investigates the pricing of patented traits in the U.S. hybrid corn seed market under imperfect competition. In a multiproduct context, we first examine how substitution/complementarity relationships among products can affect pricing. This is used to motivate multi-product generalizations of the Herfindahl-Hirschman index (GHHI) capturing cross-market effects of imperfect competition on bundle pricing. The GHHI model is applied to pricing of conventional and patented biotech seeds in the US from 2000-2007. One major finding is that standard component pricing in biotech traits is soundly rejected in favor of subadditive bundle pricing. The econometric estimates show how changes in market structures (as measured by both own- and cross-Herfindahl indexes) affect U.S. corn seed prices.

Design and fabrication of a centrifugally driven microfluidic disk for fully integrated metabolic assays on whole blood

For the first time, we present a novel and fully integrated centrifugal microfluidic “ lab-on-a-disk” for rapid metabolic assays in human whole blood. All essential steps comprising blood sampling, metering, plasma extraction and the final optical detection are conducted within t = 150 s in passive structures integrated on one disposable disk. Our technology features a novel plasma extraction structure (V = 500 nL, CV < 5%) without using any hydrophobic microfluidics where the purified plasma (cRBC< 0.11%) is centrifugally separated and subsequently extracted through a capillarily primed extraction channel into the detection chamber. While this capillary extraction requires precisely defined, narrow micro-structures, the reactive mixing and detection is most efficient within larger cavities. The corresponding manufacturing technique of these macro- and micro structures in the range of 30 µ m to 1000 µ m is also presented for the first time: A novel, cost-efficient hybrid prototyping technique of a multiscale epoxy master for subsequent hot embossing of polymer disks

CISSY: A station for preparation and surface/interface analysis of thin film materials and devices

The CISSY end station combines thin film deposition (sputtering, molecular beam epitaxy ambient-pressure methods) with surface and bulk-sensitive analysis (photo emission, x-ray emission, x-ray absorption) in the same UHV system, allowing fast and contamination–free transfer between deposition and analysis. It is mainly used for the fabrication and characterization of thin film devices and their components like thin film photovoltaic cells, water-splitting devices and other functional thin film materials

Optical beam guidance in monolithic polymer chips for miniaturized colorimetric assays

For the first time, we present a simple and robust optical concept to enable precise and sensitive read-out of colorimetric assays in flat lab-on-a-chip devices. The optical guidance of the probe beam through an incorporated measurement chamber to the detector is based on the total internal reflection at V-grooves in the polymer chip. This way, the optical path length through the flat measurement chamber and thus the performance of the measurements are massively enhanced compared to direct (perpendicular) beam incidence. This is demonstrated by a chip-based, colorimetric glucose-assay on serum. Outstanding features are an excellent reproducibility (CV= 1.91 %), a competitive lower limit of detection (cmin = 124 μM), and a high degree of linearity (R2 = 0.998) within a working range extending over nearly three orders of magnitude

Soziale Determinanten und expositionelle Risikofaktoren einer SARS-CoV-2-Infektion: Eine retrospektive Kohortenstudie

Ziel: Ziel dieser Studie war es, schnell verfügbare Risikofaktoren für eine SARS-CoV-2-Infektion im ambulanten Patientensetting zu identifizieren. In der vorliegenden Arbeit wurde der Fokus auf die vorbestehenden Risikofaktoren aus sozialem Hintergrund und Lebensweise sowie auf das Risiko nach einer Exposition gegenüber einem COVID-19-Fall gelegt. Material und Methoden: In diese retrospektive, monozentrische Kohortenstudie wurden alle Patienten eingeschlossen, die 18 Jahre oder älter waren und zwischen dem 04.04.2020 und 15.05.2020 in der Fieberambulanz Neckarpark in Stuttgart vorstellig wurden. Auf dem Untersuchungsbogen wurden neben demographischen Daten, Vorerkrankungen und Symptomen auch die Exposition gegenüber einem Infizierten, die Arbeit als Personal der Kritischen Infrastruktur, die Anzahl an (symptomatischen) Personen im gleichen Haushalt, ein Aufenthalt in einem Risikogebiet laut RKI, sowie das Rauchverhalten des Patienten dokumentiert. Ergebnisse: Von insgesamt 930 Patienten wurden 74 (8,0 %) positiv auf SARS-CoV-2 getestet. Eine Exposition gemäß Kategorie I (OR 12,20; KI 6,80 - 21,90), vor allem im gleichen Haushalt (OR 4,14; KI 1,28 - 13,33) und mit steigender Anzahl an (symptomatischen) Haushaltsmitgliedern, war mit einem erhöhten Risiko für COVID-19 verbunden. Patienten, die im Gesundheitswesen oder der kritischen Infrastruktur arbeiteten, waren ebenfalls einem erhöhten Risiko ausgesetzt (OR 2,35; KI 1,40 - 3,96). In der SARS-CoV-2-positiven Gruppe waren weniger aktive Raucher (p = < 0,001; OR 0,19; KI 0,08 - 0,44). Das auf Grundlage dieser Ergebnisse erstellte multivariate Modell zeigte eine gute Detektionsrate (AUROC = 0,77). Schlussfolgerungen: Zusammenfassend konnten wir unter den sozialen Determinanten die Kontakthistorie, das Rauchverhalten und die Anzahl an (symptomatischen) Haushaltsmitgliedern als starke Prädiktoren einer SARS-CoV-2-Infektion identifizieren. Besonders die Erkenntnisse in Bezug auf das Rauchen stellen für die Zukunft interessante Forschungsgegenstände dar

Direct hemoglobin measurement by monolithically integrated optical beam guidance

We present a concept for optical beam guidance by total internal reflection (TIR) at V-grooves as retro reflectors which are monolithically integrated on a microfluidic "lab-on-a-disk". This way, the optical path length through a measurement chamber and thus the sensitivity of colorimetric assays is massively enhanced compared to direct (perpendicular) beam incidence. With this rugged optical concept, we determine the concentration of hemoglobin (Hb) in human whole blood. Outstanding features are a high degree of linearity (R2 = 0.993) between the optical signal and the Hb together with a reproducibility of CV= 2.9 %, and a time-to-result of 100 seconds, only

Enhanced absorption in tandem solar cells by applying hydrogenated In2O3 as electrode

To realize the high efficiency potential of perovskite/chalcopyrite tandem solar cells in modules, hydrogenated In2O3 (IO:H) as electrode is investigated. IO:H with an electron mobility of 100 cm2 V−1 s−1 is demonstrated. Compared to the conventional Sn doped In2O3 (ITO), IO:H exhibits a decreased electron concentration and leads to almost no sub-bandgap absorption up to the wavelength of 1200 nm. Without a trade-off between transparency and lateral resistance in the IO:H electrode, the tandem cell keeps increasing in efficiency as the IO:H thickness increases and efficiencies above 22% are calculated. In contrast, the cells with ITO as electrode perform much worse due to the severe parasitic absorption in ITO. This indicates that IO:H has the potential to lead to high efficiencies, which is otherwise constrained by the parasitic absorption in conventional transparent conductive oxide electrode for tandem solar cells in modules

Assessment of Chemical and Electronic Surface Properties of the Cu2ZnSn(SSe)4 after Different Etching Procedures by Synchrotron-based Spectroscopies

Kesterite Cu2ZnSn(S,Se)4 absorber layers with different [S]/([S]+[Se]) ratios were studied using XPS, UPS, Hard X-ray (HIKE) photoemission and the Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS). The samples were prepared by IREC using sequentially sputtered metallic precursor stacks with metal ratios of [Cu]/([Zn]+[Sn])=0.80, [Zn]/[Sn]=1.20 followed by annealing under S+Se+Sn atmosphere. Different etching procedures were used depending on the sample's composition. It is shown that the surface composition varies from that of the bulk, especially for the Se-rich samples. Contamination with sulfur is detected after using a Na2S etching solution for the pure Se kesterite. A Cu-depleted surface was found for all samples before and after etching. HIKE measurements show a higher [Zn]/[Sn] ratio in the near surface region than on the very surface. This is explained by the fact, the etching procedure removes secondary phases from the very few surface layers, while some of ZnS(e) is still buried underneath. In order to investigate the band gap transition from the pure sulfide (1.5 eV) to the pure selenide (1eV), the valence and conduction band of the respective absorbers were probed. According to UPS and HIKE measurements, the relative distance between Fermi level (Ef) and valance band maximum (VBM) for sulfide sample was 130 meV larger than for selenide. Using NEXAFS on the copper, zinc and tin edges, the development of the conduction band with increasing [S]/([S]+[Se]) ratios was studied. Stoichiometric powder samples were used as reference materials. © 2015 Published by Elsevier Ltd.Peer ReviewedPostprint (published version

CENTRIFUGAL LABTUBE FOR FULLY AUTOMATED DNA EXTRACTION & LAMP AMPLIFICATION BASED ON AN INTEGRATED, LOW-COST HEATING SYSTEM

In this paper, we introduce a disposable battery-driven heating system for loop-mediated isothermal DNA amplification (LAMP) inside a centrifugally-driven DNA-extraction platform (LabTube). We demonstrate fully automated, fully closed extraction of as little as 100 DNA copies of verotoxin-producing (VTEC) Escherichia coli lysate in water, milk and apple juice in a standard laboratory centrifuge, followed by subsequent automatic LAMP amplification with an overall time-to-result of 1.5hrs. The system is disposable, fully closed and automated, requiring only a single pipetting step. The microcontroller-driven heating system is low-cost (<1$) and it can be easily parallelized. Because the heated LabSystem runs within a standard laboratory centrifuge, it is suitable for DNA extraction and amplification in low-resource areas, at production sites or sales locations

LOW-COST BACTERIAL DETECTION SYSTEM FOR FOOD SAFETY BASED ON AUTOMATED DNA EXTRACTION, AMPLIFICATION AND READOUT

To ensure food, medical and environmental safety and quality, rapid, low-cost and easy-to-use detection methods are desirable. Here, the LabSystem is introduced for integrated, automated DNA purification and amplification. It consists of a disposable, centrifugally-driven DNA purification platform (LabTube) and the subsequent amplification in a low-cost UV/vis-reader (LabReader). In this paper, food safety was chosen as the first sample application with pathogenic verotoxin-producing (VTEC) Escherichia coli (E.coli) in water and milk, and the product-spoiler Alicyclobacillus acidoterrestris (A acidoterrestris) in apple juice as sample organisms. DNA was amplified qualitatively using isothermal loop-mediated DNA amplification (LAMP) and quantitatively using real-time PCR. By optimizing manual purification protocols inside the LabTube, as little as 45 inserted DNA copies were extracted from E.coli and A.acidoterrestris lysates in real samples (milk, juice and water). To run isothermal DNA amplification (LAMP) and PCR inside the LabReader, temperature control as well as data analysis methods were implemented. Combined detection limits for DNA purification and amplification from bacteria lysates in real samples at 102-103 inserted copies were achieved. The demonstrated LabSystem runs with standard laboratory equipment and reduces hands-on times from 30min to 3min