Instanton Solutions for the Universal Hypermultiplet

We expand our previous analysis on fivebrane and membrane instanton solutions in the universal hypermultiplet, including near-extremal multi-centered solutions and mixed fivebrane-membrane charged instantons. The results are most conveniently described in terms of a double-tensor multiplet.Comment: Minor changes, clarification added. Contribution to the proceedings of the 36th International Symposium Ahrenshoop, August 200

Fungicide resistance among Cladobotryum spp. – causal agents of cobweb disease of the edible mushroom Agaricus bisporus

A survey of fungicide resistance among isolates of the mushroom pathogens Cladobotryum mycophilum and C. dendroides Types I and II was undertaken, with respect to the active ingredients thiabendazole, carbendazim (benzimidazoles) and prochloraz manganese following an epidemic in Britain and Ireland in 1994/95. The majority of isolates (41/57) were strongly resistant to thiabendazole (ED50 > 200 ppm) and were exclusively C. dendroides Type II. All C. mycophilum and C. dendroides Type I isolates, and four C. dendroides Type II isolates, were weakly resistant to thiabendazole (ED50 1–10 ppm). Thiabendazole-resistant C. dendroides Type II isolates were only weakly resistant to carbendazim (ED50 2–10 ppm) and isolates which were weakly resistant to thiabendazole were carbendazim-sensitive (ED50 < 1 ppm), demonstrating a lack of complete cross resistance between these two benzimidazole fungicides. The ED50 values for all isolates with respect to prochloraz manganese ranged from 0.14 to 7.8 ppm. Benzimidazole resistance was considered to have been an important factor influencing the severity of the 1994/95 cobweb epidemic but 25% of isolates collected were benzimidazole sensitive

Hypermultiplets and Topological Strings

The c-map relates classical hypermultiplet moduli spaces in compactifications of type II strings on a Calabi-Yau threefold to vector multiplet moduli spaces via a further compactification on a circle. We give an off-shell description of the c-map in N=2 superspace. The superspace Lagrangian for the hypermultiplets is a single function directly related to the prepotential of special geometry, and can therefore be computed using topological string theory. Similarly, a class of higher derivative terms for hypermultiplets can be computed from the higher genus topological string amplitudes. Our results provide a framework for studying quantum corrections to the hypermultiplet moduli space, as well as for understanding the black hole wave-function as a function of the hypermultiplet moduli.Comment: 21 pages, references adde

Supergravity description of spacetime instantons

We present and discuss BPS instanton solutions that appear in type II string theory compactifications on Calabi-Yau threefolds. From an effective action point of view these arise as finite action solutions of the Euclidean equations of motion in four-dimensional N=2 supergravity coupled to tensor multiplets. As a solution generating technique we make use of the c-map, which produces instanton solutions from either Euclidean black holes or from Taub-NUT like geometries.Comment: 35 pages, some clarifications adde

Quantitative analysis of aortic Na[¹⁸F]F uptake in macrocalcifications and microcalcifications in PET/CT scans

Background: Currently, computed tomography (CT) is used for risk profiling of (asymptomatic) individuals by calculating coronary artery calcium scores. Although this score is a strong predictor of major adverse cardiovascular events, this method has limitations. Sodium [18F]fluoride (Na[18F]F) positron emission tomography (PET) has shown promise as an early marker for atherosclerotic progression. However, evidence on Na[18F]F as a marker for high-risk plaques is limited, particularly on its presentation in clinical PET/CT. Besides, the relationship between microcalcifications visualized by Na[18F]F PET and macrocalcifications detectable on CT is unknown. Purpose: To establish a match/mismatch score in the aorta between macrocalcified plaque content on CT and microcalcification Na[18F]F PET uptake. Methods: Na[18F]F-PET/CT scans acquired in our centre in 2019–2020 were retrospectively collected. The aorta of each low-dose CT was manually segmented. Background measurements were placed in the superior vena cava. The vertebrae were automatically segmented using an open-source convolutional neural network, dilated with 10 mm, and subtracted from the aortic mask. Per patient, calcium and Na[18F]F-hotspot masks were retrieved using an in-house developed algorithm. Three match/mismatch analyses were performed: a population analysis, a per slice analysis, and an overlap score. To generate a population image of calcium and Na[18F]F hotspot distribution, all aortic masks were aligned. Then, a heatmap of calcium HU and Na[18F]F-uptake on the surface was obtained by outward projection of HU and uptake values from the centerline. In each slice of the aortic wall of each patient, the calcium mass score and target-to-bloodpool ratios (TBR) were calculated within the calcium masks, in the aortic wall except the calcium masks, and in the aortic wall in slices without calcium. For the overlap score, three volumes were identified in the calcium and Na[18F]F masks: volume of PET (PET+/CT-), volume of CT (PET-/CT+), and overlapping volumes (PET+/CT+). A Spearman's correlation analysis with Bonferroni correction was performed on the population image, assessing the correlation between all HU and Na[18F]F vertex values. In the per slice analysis, a paired Wilcoxon signed-rank test was used to compare TBR values within each slice, while an ANOVA with post-hoc Kruskal–Wallis test was employed to compare TBR values between slices. p-values &lt; 0.05 were considered significant. Results: In total, 186 Na[18F]F-PET/CT scans were included. A moderate positive exponential correlation was observed between total aortic calcium mass and total aortic TBR (r = 0.68, p &lt; 0.001). A strong positive correlation (r = 0.77, p &lt; 0.0001) was observed between CT values and Na[18F]F values on the population image. Significantly higher TBR values were found outside calcium masks than inside calcium masks (p &lt; 0.0001). TBR values in slices where no calcium was present, were significantly lower compared with outside calcium and inside calcium (both p &lt; 0.0001). On average, only 3.7% of the mask volumes were overlapping. Conclusions: Na[18F]F-uptake in the aorta behaves similarly to macrocalcification detectable on CT. Na[18F]F-uptake values are also moderately correlated to calcium mass scores (match). Higher uptake values were found just outside macrocalcification masks instead of inside the macrocalcification masks (mismatch). Also, only a small percentage of the Na[18F]F-uptake volumes overlapped with the calcium volumes (mismatch).</p

On NS5-brane instantons and volume stabilization

We study general aspects of NS5-brane instantons in relation to the stabilization of the volume modulus in Calabi-Yau compactifications of type II strings with fluxes, and their orientifold versions. These instantons correct the Kahler potential and generically yield significant contributions to the scalar potential at intermediate values of string coupling constant and volume. Under suitable conditions they yield uplifting terms that allow for meta--stable de Sitter vacua.Comment: 29 pages, 3 figures; statements about fields G^a made more precise, added some clarifications, typos correcte

Five-brane Instantons vs Flux-induced Gauging of Isometries

In five-dimensional heterotic M-theory there is necessarily nonzero background flux, which leads to gauging of an isometry of the universal hypermultiplet moduli space. This isometry, however, is poised to be broken by M5-brane instanton effects. We show that, similarly to string theory, the background flux allows only brane instantons that preserve the above isometry. The zero-mode counting for the M5 instantons is related to the number of solutions of the Dirac equation on their worldvolume. We investigate that equation in the presence of generic background flux and also, in a particular case, with nonzero worldvolume flux.Comment: 27 pages; reference adde

Are There Any Significant Differences in Terms of Age and Sex in Pedestrian and Cyclist Accidents?

This study has analyzed sex-specific differences in pedestrian and cyclist accidents involving passenger cars. The most frequently injured body regions, types of injuries, which show sex-specific differences and the general accident parameters of females and males were compared. Accident data from three different European countries (Austria, Netherlands, Sweden) were analyzed. The current analysis shows that for both, females and males, pedestrian and cyclist injuries are sustained mainly to the body regions head, thorax, upper extremities and lower extremities. The results show that the odds for sustaining skeletal injuries to the lower extremities (incl. pelvis) in females are significantly higher. It was observed in all datasets, that the odds of females being involved in a rural accident or an accident at night are lower than for males. Elderly pedestrian and cyclist (≥60YO) tend to sustain more severe injuries (AIS2+ and AIS3+) than younger pedestrian and cyclists

De Sitter vacua from N=2 gauged supergravity

Typical de Sitter (dS) vacua of gauged supergravity correspond to saddle points of the potential and often the unstable mode runs into a singularity. We explore the possibility to obtain dS points where the unstable mode goes on both sides into a supersymmetric smooth vacuum. Within N=2 gauged supergravity coupled to the universal hypermultiplet, we have found a potential which has two supersymmetric minima (one of them can be flat) and these are connected by a de Sitter saddle point. In order to obtain this potential by an Abelian gauging, it was important to include the recently proposed quantum corrections to the universal hypermultiplet sector. Our results apply to four as well as five dimensional gauged supergravity theories.Comment: 25 pages, 1 figure, add refs and corrected typo

An index for the Dirac operator on D3 branes with background fluxes

We study the problem of instanton generated superpotentials in Calabi-Yau orientifold compactifications directly in type IIB string theory. To this end, we derive the Dirac equation on a Euclidean D3 brane in the presence of background fluxes. We propose an index which governs whether the generation of a superpotential in the effective 4d theory by D3 brane instantons is possible. Applying the formalism to various classes of examples, including the K3 x T^2/Z_2 orientifold, in the absence and presence of fluxes, we show that our results are consistent with conclusions attainable via duality from an M-theory analysis.Comment: Fermion coupling to five-form restored, conclusions of the paper unchange