3-5-man chess: Maximals and mzugs

This article reports the combined results of several initiatives in creating and surveying complete suites of endgame tables (EGTs) to the Depth to Mate (DTM) and Depth to Conversion (DTC) metrics. Data on percentage results, maximals and mutual zugzwangs, mzugs, has been filed and made available on the web, as have the DTM EGTs

Common ragweed (Ambrosia artemisiifolia L.) causes severe yield losses in different soybean varieties by reducing the infection potential of Bradyrhizobium japonicum

Das ursprünglich aus Nordamerika stammende Ragweed oder Beifuß-Ambrosia (Ambrosia artemisiifolia L. (Asteraceae), íst eine einjährige, krautige Pflanze. Sie hat sich in den letzten Jahrzehnten massiv ausgebreitet und zählt heute in vielen Teilen Mitteleuropas zu den wirtschaftlich wichtigsten Unkrautarten in der Landwirtschaft. Aktuell übliche Bekämpfungsmaßnahmen wie Mähen oder Herbizidapplikationen zeigen auf vielen Standorten nur sehr eingeschränkte Erfolge, sind aus zeitlichen oder wirtschaftlichen Gründen nicht umsetzbar bzw. scheitern daran, dass der Neophyt nicht erkannt wird. Speziell Sojabohnenbestände wurden in den letzten Jahren immer stärker von Ragweed befallen, jedoch gibt es bislang nur wenige Studien zur Ertragswirkung von Ragweed. Das Ziel des zweijährigen Feld- und einjährigen Glashausversuches, die 2017 und 2018 durchgeführt wurden, war deshalb die Untersuchung der Konkurrenzeffekte von Ragweed auf 1) Wachstum (oberirdisch / unterirdisch), 2) Entwicklung, 3) Infektionspotential der Knöllchenbakterien und 4) Ertrag von zwei verschiedenen Sojabohnensorten. Die Ergebnisse der Untersuchung zeigten, dass auf den Versuchsflächen mit der höchsten Ragweed-Biomasse der Sojaertrag um 83,7 % sank. Speziell die Anzahl und das Gewicht der Knöllchen (Bradyrhizobium japonicum) auf den Sojawurzeln wurden durch Anwesenheit von Ragweed stark reduziert. Eine Ragweed-Pflanze pro Quadratmeter reichte aus, um die Anzahl der Knöllchen um durchschnittlich 55,8 % zu reduzieren. Da jedoch eine effektive Infektion wesentlich zur Ertragsbildung von Soja beiträgt, führte diese Reduktion an Knöllchenbakterien bzw. deren Gewicht zu einem Ertragsverlust von 18 %.Ambrosia artemisiifolia L. (Asteraceae) known as common ragweed is an annual herbaceous species native to North America which has become one of the economically most important weeds in agricultural areas throughout Middle Europe. Its large ecological amplitude enables the species to establish in several types of environment, but management options to effectively contain its spread are limited due to lack of efficacy, cost and time or lack of awareness. In the last decade especially soybean fields were severely affected by ragweed invasion, but until now information on the yield-decreasing effects of the plant are scarce for Middle Europe. Therefore, the aim of the study, conducted in 2017 and 2018 as a greenhouse and biennial field trial, was an evaluation of the competition effects of ragweed upon 1) growth (aboveground/belowground), 2) infection potential of rhizobia and 3) yield of two different soybean varieties. Results revealed that on plots with the highest ragweed biomass the yield loss accounted for 83.7% on average. Particularly, the numbers of nodules as well as the mean weight of the nodule, which stand in tight correlation with soybean yield, were significantly reduced by the presence of ragweed. Only one ragweed plant per square metre reduced the number of nodules by 55.8% and consequently led to a decrease in yield of 18%

Know your enemy: Are biochemical substances the secret weapon of common ragweed (Ambrosia artemisiifolia L.) in the fierce competition with crops and native weeds?

Entsprechend der „Novel Weapon“-Hypothese, kann der Invasionserfolg von nicht-heimischen Arten wie Ragweed (Ambrosia artemisiifolia L.) auf einen Verlust von natürlichen Konkurrenten zurückzuführen sein. Grund für diesen Verlust sind chemische Verbindungen, die die gebietsfremde Art erzeugt und die heimische Arten aufgrund fehlender Koevolution negativ beeinträchtigen. Studien haben gezeigt, dass die Gattung Ambrosia unterschiedliche organische Verbindungen produziert, von denen sehr viele ein breites Spektrum an biologischer Aktivität zeigen, weshalb diese chemischen Verbindungen ein wichtiger Grund für den Invasionserfolg und die Konkurrenzkraft der Pflanze sein können. Um 1) das chemische Profil der oberirdischen Biomasse offenzulegen, wurden vier verschiedene Extrakte (wässriger Extrakt, Hexan-Extrakt, Methanol-Extrakt und ätherisches Öl) hergestellt und auf ihre Inhaltsstoffe analysiert. Im nächsten Schritt wurde ein Laborexperiment durchgeführt, dass Aufschluss darüber geben sollte 2) welche Effekte unterschiedliche Konzentrationen dieser Extrakte auf Keimung und Jungpflanzenentwicklung von drei verschiedenen Kulturpflanzen (Sojabohne, Weizen und Raps), drei heimischen Unkrautarten (Chenopodium album, Senecio vulgaris und Arabidopsis thaliana) sowie auf Ragweed selbst, haben. Die Ergebnisse zeigten, eine deutliche Beeinträchtigung von Keimung und Entwicklung aller getesteten Pflanzenarten. Obwohl keiner der Extrakte eine direkte Wirkung auf die Keimfähigkeit der Kulturpflanzen hatte, konnte eine deutliche Wachstumsreduktion von Wurzel und Spross bei allen Nutzpflanzen festgestellt werden. Im Gegensatz dazu, konnte man bei den heimischen Unkrautarten und Ragweed selbst eine deutlich verminderte Keimfähigkeit sowie Wachstumshemmung speziell bei der Behandlung mit ätherischem Öl und dem wässrigen Extrakt beobachten.Following the “novel weapon hypothesis”, the invasiveness of non-native species like common ragweed (Ambrosia artemisiifolia L.) can result from a loss of natural competitors due to the production of chemical compounds by the non-native species that unfavorably affect native communities. In this case, native plants may not be able to tolerate compounds released by a non-native plant that has not co-evolved in the same environment. Particularly the genus Ambrosia produces several types of organic compounds, which have a broad spectrum of biological activities and which could be major drivers in the successful invasion and competition process of common ragweed. To 1) asses the chemical profile of the aboveground biomass of common ragweed four different extracts (H2O, hexane extract, methanol extract and essential oil) were prepared and analysed for their content substances. In the next step a laboratory experiment was implemented to 2) determine the effects of different concentrations of these substances on germination and seedling development of three different crops (soybean, wheat, and rapeseed), native weedy species (Chenopodium album, Senecio vulgaris and Arabidopsis thaliana) and on common ragweed itself. Results showed that germination as well as seedling development was significantly influenced by the chemical compounds in the extracts. Even though the extracts did not affect the germination capacity of crops, severe reduction in root and shoot growth were observed with all three tested crops. The highest inhibitory effect on germination of native weedy species as well as common ragweed was observed with essential oil and the aqueous extract

Contrasting crystal packing arrangements in triiodide salts of radical cations of chiral bis(pyrrolo[3,4-d])tetrathiafulvalenes

Crystal structures of six 1 : 1 triiodide salts of a series of enantiopure bis(pyrrolo[3,4-d])TTF derivatives, the first structures of radical cation salts reported for this bis(pyrrolo) donor system, show three different arrangements of triiodide ions, organised either in head-to-tail pairs, in infinite lines, or in a castellated arrangement. The complex crystal structures, obtained by electrocrystallisation, are influenced by the presence of solvent, for example changing an ABCABC packing arrangement to ABAB with inclusion of THF, as well as by the size of the chiral side chain

Synthetic strategies for preparing BEDT-TTF derivatives functionalised with metal ion binding groups

The syntheses of BEDT-TTF (ET) derivatives with potential metal ion binding pyridyl, bipyridyl and terpyridyl groups are achieved either by stepwise construction of the organosulfur core or via reactions of hydroxymethyl-ET for which a cheap and efficient four step route is reported. The tosylate of hydroxymethyl-ET, reported for the first time, undergoes nucleophilic substitutions with pyridyl, bipyridyl- and terpyridyl-thiolates to give new donors. The X-ray crystal structures of two substituted ET derivatives show considerable deviation of the organosulfur donor system from planarity by bending about the short molecular axis of the ET group

New chiral organosulfur donors related to bis(ethylenedithio)tetrathiafulvalene

Six new enantiopure chiral organosulfur donors, with structures related to BEDT-TTF, have been synthesised for use in the preparation of organic metals, starting either by double nucleophilic substitutions on the bis-mesylate of 2R,4Rpentane-2,4-diol or by a cycloaddition with subsequent elimination of acetic acid on the enol acetate of (+)-nopinone. Crystal structures of some of their radical cation triiodides salts and TCNQ complexes are reported

Synthesis of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) derivatives functionalised with two, four or eight hydroxyl groups

Short synthetic routes to a range of BEDT-TTF derivatives functionalised with two, four or eight hydroxyl groups are reported, of interest because of their potential for introducing hydrogen bonding between donor and anion into their radical cation salts. The cycloaddition of 1,3-dithiole-2,4,5-trithione with alkenes to construct 5,6-dihydro-1,3-dithiolo[4,5-b]1,4-dithiin-2-thiones is a key step, with homo- or hetero-coupling procedures and O-deprotection completing the syntheses. The first synthesis of a single diastereomer of tetrakis(hydroxymethyl)BEDT-TTF, the cis, trans product, was achieved by careful choice of O-protecting groups to facilitate separation of homo- and hetero-coupled products. Cyclisation of the trithione with enantiopure 1R,2R,5R,6R-bis(O,O-isopropylidene)hex-3-ene-1,2,5,6-tetrol (from D-mannitol) gave two separable diastereomeric thiones, which can be transformed to enantiomeric BEDT-TTF derivatives with four or eight hydroxyl groups

Topical Diclofenac Reprograms Metabolism and Immune Cell Infiltration in Actinic Keratosis

Background: Melanoma and squamous cell carcinoma of the skin are characterized by an altered glucose metabolism, but little is known about metabolic changes in precancerous skin lesions such as actinic keratosis (AK). Here, we studied the central carbon metabolism and immune cell infiltrate of actinic keratosis lesions before, under, and 4 weeks after treatment with topical diclofenac (Solaraze (R)). Methods: This study was designed as a prospective, randomized, controlled, monocentric investigation (ClinicalTrials.gov Identifier: NCT01935531). Myeloid and T cell infiltration was analyzed in skin biopsies from 28 patients by immunohistochemistry. Furthermore, immune cell activation was determined via quantitative real-time PCR (IFN-gamma, IL-10, CSF1 , TGF-beta, IL-6). Glucose, amino acid and Krebs' cycle metabolism was studied by mass spectrometry prior, during and after treatment with topical diclofenac. Biopsies from sun-exposed, untreated, healthy skin served as controls. Results: Increased lactate and decreased glucose levels suggested accelerated glycolysis in pre-treatment AK. Further, levels of Krebs' cycle intermediates other than citrate and amino acids were elevated. Analysis of the immune infiltrate revealed less epidermal CD1a+ cells but increased frequencies of dermal CD8+ T cells in AK. Treatment with diclofenac reduced lactate and amino acid levels in AK, especially in responding lesions, and induced an infiltration of dermal CD8+ T cells accompanied by high IFN-gamma mRNA expression, suggesting improved T cell function. Discussion: Our study clearly demonstrated that not only cancers but also pre-malignant skin lesions, like AK, exhibit profound changes in metabolism, correlating with an altered immune infiltrate. Diclofenac normalizes metabolism, immune cell infiltration and function in AK lesions, suggesting a novel mechanism of action