Tropical Skeletons

In this paper, we study the interplay between tropical and analytic geometry for closed subschemes of toric varieties. Let $K$ be a complete non-Archimedean field, and let $X$ be a closed subscheme of a toric variety over $K$. We define the tropical skeleton of $X$ as the subset of the associated Berkovich space $X^{\rm an}$ which collects all Shilov boundary points in the fibers of the Kajiwara--Payne tropicalization map. We develop polyhedral criteria for limit points to belong to the tropical skeleton, and for the tropical skeleton to be closed. We apply the limit point criteria to the question of continuity of the canonical section of the tropicalization map on the multiplicity-one locus. This map is known to be continuous on all torus orbits; we prove criteria for continuity when crossing torus orbits. When $X$ is sch\"on and defined over a discretely valued field, we show that the tropical skeleton coincides with a skeleton of a strictly semistable pair, and is naturally isomorphic to the parameterizing complex of Helm--Katz.Comment: 42 pages. The introduction was rewritten. Corollary 8.15 was renamed to Theorem 8.1

Skeletons and tropicalizations

Let $K$ be a complete, algebraically closed non-archimedean field with ring of integers $K^\circ$ and let $X$ be a $K$-variety. We associate to the data of a strictly semistable $K^\circ$-model $\mathscr X$ of $X$ plus a suitable horizontal divisor $H$ a skeleton $S(\mathscr X,H)$ in the analytification of $X$. This generalizes Berkovich's original construction by admitting unbounded faces in the directions of the components of H. It also generalizes constructions by Tyomkin and Baker--Payne--Rabinoff from curves to higher dimensions. Every such skeleton has an integral polyhedral structure. We show that the valuation of a non-zero rational function is piecewise linear on $S(\mathscr X, H)$. For such functions we define slopes along codimension one faces and prove a slope formula expressing a balancing condition on the skeleton. Moreover, we obtain a multiplicity formula for skeletons and tropicalizations in the spirit of a well-known result by Sturmfels--Tevelev. We show a faithful tropicalization result saying roughly that every skeleton can be seen in a suitable tropicalization. We also prove a general result about existence and uniqueness of a continuous section to the tropicalization map on the locus of tropical multiplicity one.Comment: 44 pages, 2 figures. Version 3: minor errors corrected; Remark 3.14 expanded. Final version, to appear in Advances in Mathematic

Genetic variability among Beauveria brongniartii (Saccardo) Petch isolates fromvarious geographical and host origins based on AFLP analysis

The entomopathogenic hyphomycete Beauveria brongniartii is a promising candidate for biocontrol of economically important agricultural and forest pests. Assessment of genetic relatedness of this species appears to be essential to gain insight into the monitoring of such biocontrol products. Distinction of Beauveria spp. strains with different virulence to target organisms revealed to be a serious constraint in the development of successful biocontrol using these important species. Thus, there is a need to find ways to monitor these strains when applied to natural agents. We have used amplified fragment length polymorphism (AFLPs) markers to estimate genetic variations among fourteen isolates (ten B. brongniartii, two B. bassiana (BALSAMO) VUILLEMIN and two Nomuraea rileyi (FARLOW) SAMSON) obtained from different geographical origins and hosts with differing virulence to scarabs. Seven different AFLP primer combinations yielded a total of 229 AFLP fragments comprised between 30 (EcoRI-ACA/Tru1l-C) to 57 (EcoRI-AAG/Tru1l-CTT) AFLP markers with an average of 54 amplified fragments per primer combination. Fragment size varied between 50-541 base pairs (bp) among the ten B. brongniartii isolates analysed in this study achieving a good resolution between the isolates. The cluster analysis based on genetic distance values clustered all isolates at above 0.40 similarity and demonstrated that some B. brongniartii isolates from distinct geographical origins and various hosts showed a greater genetic variability

Immunosuppressive therapy in lung transplantation: state of the art

The coming of age of lung transplantation is accompanied by an immunosuppressive armamentarium that has been brought forward from other transplant indications. Widely employed on the basis of few small randomized studies, and mostly single-center experience or empirical expert knowledge, anti-rejection therapeutic strategies in pulmonary transplantation have hardly been rigorously evaluated in large-scale prospective international trials. This review compiles the available findings on the use of current immunosuppressants in clinical lung transplantation, accentuating high level-of-evidence study results. Reporting on recent meeting and registry data, and assembling ongoing relevant trials from international databases, this article serves as an update on the state of the art of immunosuppression in lung transplantatio

High-resolution measurements of atmospheric molecular hydrogen and its isotopic composition at the West African coast of Mauritania

Oceans are a net source of molecular hydrogen (H-2) to the atmosphere, where nitrogen (N-2) fixation is assumed to be the main biological production pathway followed by photochemical production from organic material. The sources can be distinguished using isotope measurements because of clearly differing isotopic signatures of the produced hydrogen. Here we present the first ship-borne measurements of atmospheric molecular H-2 mixing ratio and isotopic composition at the West African coast of Mauritania (16-25 degrees W, 17-24 degrees N). This area is one of the biologically most active regions of the world's oceans with seasonal upwelling events and characterized by strongly differing hydrographical/ biological properties and phytoplankton community structures. The aim of this study was to identify areas of H-2 production and distinguish H-2 sources by isotopic signatures of atmospheric H-2. For this more than 100 air samples were taken during two cruises in February 2007 and 2008. During both cruises a transect from the Cape Verde Islands towards the Mauritanian Coast was sampled to cover differing oceanic regions such as upwelling and oligotrophic regimes. In 2007, additionally, four days were sampled at high resolution of one sample per hour to investigate a possible diurnal cycle of atmospheric H-2. Our results indicate the influence of local sources and suggest the Banc d'Arguin as a pool for precursors for photochemical H-2 production, whereas oceanic N-2 fixation could not be identified as a source for atmospheric H-2 during these two cruises. The variability in diurnal cycles is probably influenced by released precursors for photochemical H-2 production and also affected by a varying origin of air masses. This means for future investigations that only measuring the mixing ratio of H-2 is insufficient to explain the variability of an atmospheric diurnal cycle and support is needed, e.g. by isotopic measurements. Nevertheless, measurements of atmospheric H-2 mixing ratios, which are easy to conduct online during ship cruises, could be a useful indicator of production areas of biological precursors such as volatile organic compounds (VOCs) for further investigations

Donor predicted post-operative forced expiratory volume in one second predicts recipients' best forced expiratory volume in one second following size-reduced lung transplantation

Objective: The limited number of available grafts is one of the major obstacles of lung transplantation. Size-reduced lung transplantation allows the use of oversized grafts for small recipients. Optimal lung size matching is vital to achieve best functional outcome and avoid potential problems when using oversized grafts. We hypothesise that donor-predicted postoperative forced expiratory volume in 1s (ppoFEV1) correlates with the recipient best FEV1 after size-reduced lung transplant, being useful for the estimation of function outcome. Methods: All patients undergoing size-reduced or standard bilateral lung transplantation were included (1992-2007). Donor ppoFEV1 was calculated and corrected with respect to size reduction and correlated with recipient measured best FEV1 post-transplant. In addition, pre- and postoperative clinical data including surgical complications and outcome of all size-reduced lung transplant recipients were compared with standard lung transplant recipients. Results: A total of 61 size-reduced lung transplant recipients (lobar transplants, n=20; anatomic or non-anatomic resection, n=41) were included and compared to 145 standard transplants. The mean donor-recipient height difference was statistically significant between the two groups (p=0.0001). The mean donor ppoFEV1 was comparable with recipient best FEV1 (2.7±0.6 vs 2.6±0.7 l). There was a statistically significant correlation between donor ppoFEV1 and recipient best FEV1 (p=0.01, r=0.688). The 30-day mortality rate and 3-month, 1- and 5-year survival rates were comparable between the two groups. Conclusions: In size-reduced lung transplantation, postoperative recipient best FEV1 could be predicted from donor-calculated and corrected FEV1 with respect to its size reduction. Compared to standard lung transplantation, equivalent morbidity, mortality and functional results could be obtained after size-reduced lung transplantatio

Einsatz molekularer Marker zur Analyse der genetischen Diversität unterschiedlicher Populationen der Blutlauszehrwespe, Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae)

Die Blutlaus Eriosoma lanigerum (Hausmann) wurde Ende des 18. Jahrhunderts nach Europa eingeschleppt. E. lanigerum ist ein Schädling des Apfels, wobei es durch die Saugtätigkeit der Aphiden zu Wuchshemmungen (Blutlauskrebs, Blutlausgallen) infolge von Stoffwechselstörungen, zu irreversiblen Trieb- und Knospenschäden bis hin zum Absterben des Baumes kommen kann. Durch ihre versteckte Lebensweise unter den Rindenschuppen des Baumes sowie auf Grund von flüssigkeitsabweisenden Wachsausscheidungen sind die Tiere sehr gut gegen chemische Bekämpfungsmaßnahmen geschützt. Alternativ kann eine biologische Bekämpfung über den natürlichen Gegenspieler der Blutlaus, die Blutlauszehrwespe Aphelinus mali (HALDEN), erfolgen. Zwar kann sich diese Zehrwespe in wärmeren Gebieten sehr gut vermehren, bei niedrigen Frühjahrstemperaturen kann die Populationsdichte aber stark minimiert werden oder ganz einbrechen. Auch feuchte Witterung wird von A. mali nicht gut vertragen und schmälert die Parasitierungsraten. Die Blutlauszehrwespe hat einen Entwicklungsnullpunkt bei 8,3 bis 9,0°C, während die Blutlaus erst bei ca. 5°C ihre Entwicklung einstellt. Damit ergibt sich die Frage, ob es Biotypen dieser Schlupfwespe gibt, die möglicherweise besser an die vor Ort herrschenden Klimabedingungen angepasst sind. Ziel der vorliegenden Untersuchungen war es daher, das Ausmaß der genetischen Diversität zwischen einzelnen Populationen zu erfassen und somit Aussagen über eventuell auftretende Biotypen der Wespe treffen zu können.The endoparasitoid Aphelinus mali (HALDEMAN) (Hymenoptera: Aphelinidae) has been introduced from its native home North America to Europe in 1920 as a biological control agent for the woolly apple aphid Eriosoma lanigerum (HAUSMANN). When A. mali appears early in spring with the temperatures being relatively low at this time, the rate of parasitism and consequently the effectivity of the parasite is quite low. Thus, an identification and a subsequent release of A. mali biotypes which might be better adapted to the prevailing environmental conditions could result in higher parasitisation rates by this parasitoid. As a first step towards the identification of A. mali biotypes we examined the extent of genetic diversity in A. mali field populations and in individuals from a laboratory rearing A. mali was collected from different regions such as Germany (BBA Dossenheim, Lake Constance, Altes Land, Stuttgart-Mühlhausen, Ahrweiler), Canada, France, Italy and the Netherlands and genomic DNA was analysed using the AFLP-Technique (Amplified Fragment Length Polymorphism) as well as amplification and sequence analysis of the ITS-2 (Internally Transcribed Spacer) region