Power Integral Points on Elliptic Curves

This thesis looks at some of the modern approaches towards the solution of Diophantine equations, and utilizes them to display the nonexistence of perfect powers occurring in certain types of sequences. In particular we look at the denominator divisibility sequences (Bn) formed by Mordell elliptic curves ED : y2 = x3+D. For the curve-point pair (E−2, P), where E−2 : y2 = x3 −2, and P = (3, 5) is a nontorsion point, we prove that no term Bn is a perfect 5th power, and we give the explicit bound p � 137 for any term in the associated elliptic denominator sequence to be a perfect power Bn = Zpn for 1 < n < 113762879. We then look at obtaining upper bounds on p for the seventy-two rank 1 Mordell curves in the range |D| < 200 to possess a pth perfect power. This is done by consideration of the finite number of rational and irrational newforms corresponding to an also finite number of levels of these newforms: in thirty cases we give a bound via examination of both the rational and irrational cases, and for the remaining forty-two cases our bound is merely for the rational case due to computational limitations

Theoretical simulations and ultrafast pump-probe spectroscopy experiments in pigment-protein photosynthetic complexes

Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations;Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna;The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum;Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by inhomogeneous broadening and as such, are quite sensitive to diagonal energy disorder;The experimental anisotropies exhibit strong oscillations with ~220 fs period for certain wavelengths in one-color absorption difference experiments. The oscillations only appear when the laser pulse spectrum overlaps both of the lowest-energy groups of exciton levels clustered near 815 and 825 nm. Results suggest that the oscillations stem from quantum beating between exciton levels, rather than from coherent nuclear motion

Effects of social defeat on iK-ba inflammatory signaling in male c57BL/6J

An estimated 30 million people in the United States have been diagnosed with mood and anxiety disorders. Unfortunately, many of these patients do not adequately respond to current pharmacotherapies, so developing new drugs and strategies to treat such disorders is critically important. There are only a few drugs on the market that target neuroinflammation. Thus, it's critical that we identify anti-inflammatory agents that effectively reduce neuroinflammatory responses, hereby expanding or augmenting available options for treating neurological disorders. Previous work has shown that the derivative of naltrexone, B-funaltrexamine (B-FNA), inhibits inflammatory signaling in human astrocytes in reduced expression of proinflammatory chemokines. IKBa is one of the specific signaling proteins in the inflammation pathway

Methane activation and exchange by titanium-carbon multiple bonds

We demonstrate that a titanium-carbon multiple bond, specifically an alkylidyne ligand in the transient complex, (PNP)Ti≡C^(t)Bu (A) (PNP^− = N[2-P(CHMe_2)_(2)-4-methylphenyl]_2), can cleanly activate methane at room temperature with moderately elevated pressures to form (PNP)Ti=CHtBu(CH_3). Isotopic labeling and theoretical studies suggest that the alkylidene and methyl hydrogens exchange, either via tautomerization invoking a methylidene complex, (PNP)Ti=CH_(2)(CH_(2)^(t)Bu), or by forming the methane adduct (PNP)Ti≡C^(t)Bu(CH_4). The thermal, fluxional and chemical behavior of (PNP)Ti=CH^(t)Bu(CH_3) is also presented in this study

18F-FET PET/CT in Advanced Head and Neck Squamous Cell Carcinoma: an Intra-individual Comparison with 18F-FDG PET/CT

Purpose: To assess the diagnostic value of O-2-fluoro-18(F)-ethyl-l-tyrosine (18F-FET) positron emission tomography/computed tomography (PET/CT) for patients with advanced head and neck squamous cell carcinoma compared with 18F-fluoro-2-deoxy-d-glucose (18F-FDG) PET/CT at initial staging and following radiochemotherapy. Procedures: Thirteen patients were prospectively enrolled; each of them underwent an 18F-FDG PET/CT and 18F-FET PET/CT before treatment. Ten of those were scanned 10weeks after treatment. Results: Sensitivity, specificity, and accuracy for 18F-FDG PET/CT (primary and lymph node metastases) at initial staging were 89%, 50%, and 81%. For 18F-FET PET/CT the numbers were 70%, 90%, and 74%. Sensitivity, specificity, and accuracy for 18F-FDG PET/CT at follow-up were 71%, 65%, and 67%. For 18F-FET PET/CT the numbers were 29%, 100%, and 83%. Additionally, 18F-FDG PET/CT detected a higher number of second malignancies or distant metastases. Conclusions: 18F-FET is no substitute for 18F-FDG. Although it is more specific, too many malignant lesions are missed due to its lower sensitivit

Blood Mercury Levels of Zebra Finches Are Heritable: Implications for the Evolution of Mercury Resistance

Mercury is a ubiquitous metal contaminant that negatively impacts reproduction of wildlife and has many other sub-lethal effects. Songbirds are sensitive bioindicators of mercury toxicity and may suffer population declines as a result of mercury pollution. Current predictions of mercury accumulation and biomagnification often overlook possible genetic variation in mercury uptake and elimination within species and the potential for evolution in affected populations. We conducted a study of dietary mercury exposure in a model songbird species, maintaining a breeding population of zebra finches (Taeniopygia guttata) on standardized diets ranging from 0.0–2.4 μg/g methylmercury. We applied a quantitative genetics approach to examine patterns of variation and heritability of mercury accumulation within dietary treatments using a method of mixed effects modeling known as the \u27animal model\u27. Significant variation in blood mercury accumulation existed within each treatment for birds exposed at the same dietary level; moreover, this variation was highly repeatable for individuals. We observed substantial genetic variation in blood mercury accumulation for birds exposed at intermediate dietary concentrations. Taken together, this is evidence that genetic variation for factors affecting blood mercury accumulation could be acted on by selection. If similar heritability for mercury accumulation exists in wild populations, selection could result in genetic differentiation for populations in contaminated locations, with possible consequences for mercury biomagnification in food webs

Transcriptomic responses of the heart and brain to anoxia in the Western Painted turtle

Painted turtles are the most anoxia-tolerant tetrapods known, capable of surviving without oxygen for more than four months at 3°C and 30 hours at 20°C. To investigate the transcriptomic basis of this ability, we used RNA-seq to quantify mRNA expression in the painted turtle ventricle and telencephalon after 24 hours of anoxia at 19°C. Reads were obtained from 22,174 different genes, 13,236 of which were compared statistically between treatments for each tissue. Total tissue RNA contents decreased by 16% in telencephalon and 53% in ventricle. The telencephalon and ventricle showed ≥ 2x expression (increased expression) in 19 and 23 genes, respectively, while only four genes in ventricle showed ≤ 0.5x changes (decreased expression). When treatment effects were compared between anoxic and normoxic conditions in the two tissue types, 31 genes were increased (≥ 2x change) and 2 were decreased (≤ 0.5x change). Most of the effected genes were immediate early genes and transcription factors that regulate cellular growth and development; changes that would seem to promote transcriptional, translational, and metabolic arrest. No genes related to ion channels, synaptic transmission, cardiac contractility or excitation-contraction coupling changed. The generalized expression pattern in telencephalon and across tissues, but not in ventricle, correlated with the predicted metabolic cost of transcription, with the shortest genes and those with the fewest exons showing the largest increases in expression

Formulierungshilfen für Forschungsdatenzentren zum Thema Nutzungsbedingungen

Das vorliegende Dokument wurde im Rahmen des Netzwerks "Verbund Forschungsdaten Bildung" entwickelt und bietet eine Zusammenstellung von Formulierungsbeispielen für Nutzungsbedingungen für Forschungsdatenzentren. In Nutzungsbedingungen werden die Rechte und Pflichten der Datennutzenden sowie des datenbereitstellenden Forschungsdatenzentrums definiert

30-days mortality in patients with perforated peptic ulcer: A national audit

Anne Nakano1,4, J&amp;oslash;rgen Bendix2, Sven Adamsen3, Daniel Buck4, Jan Mainz5, Paul Bartels1, Bente N&amp;oslash;rg&amp;aring;rd4,61The Danish National Indicator Project, Regionshuset Aarhus, Aarhus, Denmark; 2Department of Gastrointestinal Surgery L, Aarhus University Hospital, Denmark; 3Digestive Disease Center, Section for Gastrointestinal Surgery, Copenhagen, Denmark; University Hospital Herlev, Denmark; 4Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 5Department of Psychiatry Region North, Denmark and Institute of Public Health, University of Southern Denmark, Odense, Denmark; 6Center for National Clinical Databases, South, Odense University Hospital, and Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, DenmarkBackground: In 2005, The Danish National Indicator Project (DNIP) reported findings on patients hospitalized with perforated ulcer. The indicator &amp;ldquo;30-days mortality&amp;rdquo; showed major discrepancy between the observed mortality of 28% and the chosen standard (10%).Rationale: An audit committee was appointed to examine quality problems linked to the high mortality. The purpose was to (i) examine patient characteristics, (ii) evaluate the appropriateness of the standard, and (iii) audit all cases of deaths within 30 days after surgery.Methods: Four hundred and twelve consecutive patients were included and used for the analyses of patient characteristics. The evaluation of the standard was based on a literature review, and a structured audit was performed according to the 115 deaths that occurred.Results: The mean age was 69.1 years, 42.0% had one co-morbid disease and 17.7% had two co-morbid diseases. 45.9% had an American Association of Anaesthetists score of 3&amp;ndash;4. We found no results on mortality in studies similar to ours. The audit process indicated that the postoperative observation of patients was insufficient.Discussion: As a result of this study, the standard for mortality was increased to 20%, and the new indicators for postoperative monitoring were developed. The DNIP continues to evaluate if these initiatives will improve the results on mortality.Keywords: mortality, perforated peptic ulcer, ulcer, audi