RISK ASSESSMENT PROVISIONS OF IMPORT AND EXPORT REGULATIONS

Risk and Uncertainty, International Relations/Trade,

A POLICY PERSPECTIVE ON IMPROVING BENEFIT/COST ANALYSIS: THE CASE OF HACCP AND MICROBIAL FOOD SAFETY

HACCP, cost/benefit analysis, food safety, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,

A recursive approach for geometric quantifiers of quantum correlations in multiqubit Schr\"odinger cat states

A recursive approach to determine the Hilbert-Schmidt measure of pairwise quantum discord in a special class of symmetric states of $k$ qubits is presented. We especially focus on the reduced states of $k$ qubits obtained from a balanced superposition of symmetric $n$-qubit states (multiqubit Schr\"odinger cat states) by tracing out $n-k$ particles $(k=2,3, \cdots ,n-1)$. Two pairing schemes are considered. In the first one, the geometric discord measuring the correlation between one qubit and the party grouping $(k-1)$ qubits is explicitly derived. This uses recursive relations between the Fano-Bloch correlation matrices associated with subsystems comprising $k$, $k-1$, $\cdots$ and $2$ particles. A detailed analysis is given for two, three and four qubit systems. In the second scheme, the subsystem comprising the $(k-1)$ qubits is mapped into a system of two logical qubits. We show that these two bipartition schemes are equivalents in evaluating the pairwise correlation in multi-qubits systems. The explicit expressions of classical states presenting zero discord are derived.Comment: 26 page

New Platforms for Optical Biosensing

Physicochemical experimental techniques combined with the specificity of a biological recognition system have resulted in a variety of new analytical devices known as biosensors. Biosensors are under intensive development worldwide because they have many potential applications, e.g. in the fields of clinical diagnostics, food analysis, and environmental monitoring. Much effort is spent on the development of highly sensitive sensor platforms to study interactions on the molecular scale. In the first part, this thesis focuses on exploiting the biosensing application of nanoporous gold (NPG) membranes. NPG with randomly distributed nanopores (pore sizes less than 50 nm) will be discussed here. The NPG membrane shows unique plasmonic features, i.e. it supports both propagating and localized surface plasmon resonance modes (p SPR and l-SPR, respectively), both offering sensitive probing of the local refractive index variation on/in NPG. Surface refractive index sensors have an inherent advantage over fluorescence optical biosensors that require a chromophoric group or other luminescence label to transduce the binding event. In the second part, gold/silica composite inverse opals with macroporous structures were investigated with bio- or chemical sensing applications in mind. These samples combined the advantages of a larger available gold surface area with a regular and highly ordered grating structure. The signal of the plasmon was less noisy in these ordered substrate structures compared to the random pore structures of the NPG samples. In the third part of the thesis, surface plasmon resonance (SPR) spectroscopy was applied to probe the protein-protein interaction of the calcium binding protein centrin with the heterotrimeric G-protein transducin on a newly designed sensor platform. SPR spectroscopy was intended to elucidate how the binding of centrin to transducin is regulated towards understanding centrin functions in photoreceptor cells.Physikochemische instrumentelle Techniken, die mit der Spezifität eines biologischen Erkennungssystems kombiniert sind, resultierten in unzähligen neuen analytischen Geräten bekannt als Biosensoren. In die Entwicklung von Biosensoren wird weltweit viel investiert angesichts der zahlreichen potentiellen Anwendungen, wie z.B. in der klinischen Diagnostik, der Nahrungsmittelanalyse und zur Umweltüberwachung. Hochempfindliche Sensor-Plattfor-men werden benötigt, um Wechselwirkungen auf molekularer Ebene zu studieren. Im ersten Teil der Doktorarbeit werden nanoporöse Gold (NPG)-Membranen im bezug auf ihre biosensorische Anwendung untersucht. NPG Proben mit einer willkürlichen Porengrößenverteilung (Poren von weniger als 50 nm) werden hierzu erforscht. Die NPG Membranen zeigen einzigartige plasmonische Eigenschaften, d.h. propagierende und lokalisierte Oberflächenplasmonresonanzmodi (p-SPR bzw. l-SPR) können gleichzeitig angeregt werden. Beide Moden ermöglichen eine sensitive Detektion der lokalen Brechungsindexveränderung an/im nanoporösen Gold Substrat. Der große Vorteil der Brechungsindexsensoren im Vergleich zu fluoreszenz-optischen Biosensoren besteht darin, daß keine chromophore Gruppe oder Lumineszenzmarkierung zur Detektion benötigt wird. Im zweiten Teil der Arbeit wurden macroporöse, aus Gold und Silica zusammengesetzte inverse Opale auf ihre bio- bzw. chemischen Sensorfähigkeiten hin analysiert. Diese Substrate kombinieren den Vorzug einer großen verfügbaren Oberfläche mit einer hoch geordneten Gitterstruktur. Das Plasmonensignal ist bei einer geordneten Substratstruktur weniger verrauscht als es bei der willkürlichen Anordnung der Poren im NPG der Fall ist. Im dritten Teil der Doktorarbeit wird die Oberfächenplasmonenresonanz (SPR) Spektroskopie angewendet, um die Protein-Protein Wechselwirkung zwischen dem Calcium bindenden Protein Centrin und dem heterotrimeren G-Protein Transducin zu erforschen. Dazu wurde eine neue Sensorplattform entwickelt. Die SPR Spektroskopie sollte aufklären, wie die Bindung des Centrins zum Transducin reguliert wird und zum besseren Verständnis der Centrinfunktionen in den Photorezeptorzellen beitragen

Synthesis and Reactivity of Acyclic (pentadienyl)iron(1+) Cations: Model Studies for the Preparation of the 8\u3cem\u3eE\u3c/em\u3e,10\u3cem\u3eZ\u3c/em\u3e,16\u3cem\u3eE\u3c/em\u3e,18\u3cem\u3eE\u3c/em\u3e-Tetraene Segment of Macrolactin A

The dicarbonyl(1,2-dimethylpentadienyl)triphenylphosphineiron(1+) cation (11) has been prepared from methyl 4-methyl-2E,4E-hexadienoate in four steps. The cation (11) reacts with hydride and carbon nucleophiles in a regiospecific fashion to afford (3-methyl-2E,4Z-diene)iron complexes. Dicarbonyl(3-methyl-7-nitro-2E,4Z-heptadiene)triphenylphosphineiron (15), the product from the reaction of 11 with nitromethane anion, has been utilized as a precursor for nitrile oxide–olefin cyclocondensations

Reaction of tricarbonyl(dienal)iron complexes with B-allyldiisopinocampheylborane

Addition of allyldiisopinocampheylborane to racemic (dienal)iron complexes, followed by oxidation, affords diastereomeric (1,4,6-trien-3-ol)iron complexes with moderate to low enantioselectivity. The high enantioselectivity typically observed for this allylborane reagent is attenuated by steric interaction between the Fe(CO)3 group and the chiral isopinocampheyl groups. Further diminution of the enantioselectivity is observed for dienal complexes in which one rotomer predominates

Fano hypersurfaces and Calabi-Yau supermanifolds

In this paper, we study the geometrical interpretations associated with Sethi's proposed general correspondence between N = 2 Landau-Ginzburg orbifolds with integral \hat{c} and N = 2 nonlinear sigma models. We focus on the supervarieties associated with \hat{c} = 3 Gepner models. In the process, we test a conjecture regarding the superdimension of the singular locus of these supervarieties. The supervarieties are defined by a hypersurface \widetilde{W} = 0 in a weighted superprojective space and have vanishing super-first Chern class. Here, \widetilde{W} is the modified superpotential obtained by adding as necessary to the Gepner superpotential a boson mass term and/or fermion bilinears so that the superdimension of the supervariety is equal to \hat{c}. When Sethi's proposal calls for adding fermion bilinears, setting the bosonic part of \widetilde{W} (denoted by \widetilde{W}_{bos}) equal to zero defines a Fano hypersurface embedded in a weighted projective space. In this case, if the Newton polytope of \widetilde{W}_{bos} admits a nef partition, then the Landau-Ginzburg orbifold can be given a geometrical interpretation as a nonlinear sigma model on a complete intersection Calabi-Yau manifold. The complete intersection Calabi-Yau manifold should be equivalent to the Calabi-Yau supermanifold prescribed by Sethi's proposal.Comment: 24 pages, uses JHEP3.cls; v2: minor corrections, references adde