Early fragmentation in the adaptive voter model on directed networks

We consider voter dynamics on a directed adaptive network with fixed out-degree distribution. A transition between an active phase and a fragmented phase is observed. This transition is similar to the undirected case if the networks are sufficiently dense and have a narrow out-degree distribution. However, if a significant number of nodes with low out degree is present, then fragmentation can occur even far below the estimated critical point due to the formation of self-stabilizing structures that nucleate fragmentation. This process may be relevant for fragmentation in current political opinion formation processes.Comment: 9 pages, 8 figures as published in Phys. Rev.

Ordered and linked chordal graphs

A graph G is called k-ordered if for every sequence of k distinct vertices there is a cycle traversing these vertices in the given order. In the present paper we consider two novel generalizations of this concept, k-vertex-edge-ordered and strongly k-vertex-edge-ordered. We prove the following results for a chordal graph G: (a) G is (2k-3)-connected if and only if it is k-vertex-edge-ordered (k ≥ 3). (b) G is (2k-1)-connected if and only if it is strongly k-vertex-edge-ordered (k ≥ 2). (c) G is k-linked if and only if it is (2k-1)-connected

Habitat tracking, range dynamics and palaeoclimatic significance of Eurasian giant salamanders (Cryptobranchidae) - indications for elevated Central Asian humidity during Cenozoic global warm periods

Environmental fluctuations are a driving force in vertebrate evolution,but cryptobranchids (giant salamanders) show little morphologic changesince the Jurassic. Here we analyze their fossil distribution in theCenozoic of Eurasia and show that morphologic stasis is also maintainedby stable environments, making giant salamanders an ideal proxy-groupfor environmental and palaeoclimatic studies. The climate space ofrecent and fossil cryptobranchids is best characterized by high humiditywith mean annual precipitation values over 900 mm. The recordedpatchiness of their fossil record can be explained by habitat trackingand/or range expansion from higher altitudes into lowland settingsduring humid periods with increased basinal relief. In Central Asiacryptobranchids are recorded from five intervals, four of them areglobal warm periods: Paleocene-Eocene Thermal Maximum, Late Oligocenewarming, Miocene Climate Optimum, and Mio-Pliocene transition. Thisdistribution suggests that during global warmth the Asian cold highpressure zone during winter months may be weak or absent, thus moistwesterly winds penetrate far into the continent. The presence ofcryptobranchids also indicates that the aridification across theEocene-Oligocene boundary as reported from Mongolia and northwesternChina, does not occur in the Zaysan Basin, probably due to increasedupslope precipitation in the rising Altai Mountains

Use of bio-waste as fertiliser for the protected vegetable cultivation

The number of biogas plants in Germany is increasing from 3,711 in 2007 to 8,075 in 2016. In these biogas plants, it occurred more than 50 Mt digestate. Therefore, several investigations are started to use digestate as organic fertiliser mostly for field crop cultivation. Experiment with tomatoes was carried out were digestate was used as a supplement to the growing media in an amount of 5%, 15%, and 25%, compared with a treatment of mineral fertiliser and lupine wholemeal. The tomato yield was highest in the treatment with mineral fertilisation, the yield with 25% digestate was only a little lower. More experiments are necessary for particular regarding the amount and frequency of fertilization with digestate from biogas plants. In Germany and in Vietnam the number of sheep flocks is increasing, high amounts of uncleaned sheep wool are available. Because of the high amount of nutrients - especially nitrogen -, sheep wool pellets could be used as multi-functional fertiliser in vegetable cultivations. Four types of sheep wool pellets have been tested in protected cultivation. Tomatoes were cultivated in a greenhouse using substrate culture with perlite, bark compost, sheep wool slabs, respectively, and sheep wool pellets as fertiliser. Best growth and highest yield for tomatoes were obtained using pine bark and perlite as a substrate, both fertilised with sheep wool pellets. Based on the results of the yield and the analyses of the nutrient content in plants it seems that sheep wool pellets can be used, for the cultivation of vegetables in greenhouses.Số lượng các nhà máy biogas tại CHLB Đức tăng từ 3.711 năm 2017 lên 8.075 năm 2016. Các nhà máy biogas sản sinh ra hơn 50 triệu tấn chất thải. Vì vậy đã có nhiều nghiên cứu liên quan đến sử dụng nguồn chất thải này làm phân bón hữu cơ cho canh tác nông nghiệp. Thí nghiệm với cà chua sử dụng chất thải biogas làm chất bổ sung dinh dưỡng cho giá thể trồng cây theo các tỷ lệ 5%, 15% và 25% đối chứng với công thức sử dụng phân hóa học và bột nguyên vỏ họ đậu. Năng suất cà chua thu được từ các công thức bổ sung chất thải biogas đều cao hơn đối chứng, chỉ có công thức bổ sung 25% có năng suất thấp hơn. Tuy nhiên vẫn cần có những nghiên cứu tiêp theo về lượng và tần xuất sử dụng bón phân với chất thải từ nhà máy biogas. Ở Đức và ở Việt Nam số lượng đàn cừu đang tăng lên, một lượng lớn lông cừu phế phẩm phát sinh. Với hàm lượng dinh dưỡng cao, đặc biệt là nitơ, viên nén từ lông cừu phế phẩm có thể sử dụng làm phân bón đa chức năng cho trồng trọt. Nghiên cứu đã sử dụng 4 loại viên nén lông cừu làm phân bón trong điều kiện trồng có kiểm soát. Cà chua được trồng trong nhà kính với 3 loại giá thể là perlite, vỏ cây thông đã ủ hoai, thảm lông cừu với phân bón là viên nén từ lông cừu phế phẩm. Năng suất cao nhất và đem lại sinh trưởng tốt nhất cho cây cà chua là công thức sử dụng vỏ cây thông và perlite. Dựa trên kết quả về năng suất và phân tích dinh dưỡng trong cây và sản phẩm, nghiên cứu cho thấy sự phù hợp của viên nén từ lông cừu phế phẩm làm phân bón cho canh tác rau trong nhà kính

Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation Systems Using Biostimulators

Cultivation of cucumber in greenhouses is predominantly carried out in soilless cultivation systems mainly in substrate culture. The use of organic and completely compostable substrates is of rising interest in such systems, unclean sheep wool was formed as substrate slabs, peat slabs and coconut fiber slabs were compared with mineral substrates rockwool and perlite. In general can be stated, intensively in greenhouses cultivated crops such as cucumbers, suffer often from inadequate abiotic or biotic growth conditions in particular in the rhizosphere. Many studies were done to find growth promoters or biostimulators to stabilize the growing condition in the rhizosphere, in case of stress situation as fluctuating salt concentration EC and pH value, but also in case of temperature stress. K-Humate, Lactate and Bacillus subtilis were investigated as biostimulators in such situations. Different concentration and combination of these biostimulators were investigated but also the methods of application on leaves and roots respectively. Very successful was used for the stabilization of the EC value for cucumber plants growing in substrate the application of K-Humate and B. subtilis (FZB24®) as single component and combined. Following the results, it can be assumed, the application of the combined biostimulators with all substances if applied over the roots was a stimulating effect visible, whereas if applied over the leaves an inhibiting effect for cucumber plant growth. Application of the biostimulators solution with all three components BS-FZB24® (0.2%), K-Humate (0.01%), and LACTOFOL “O” (0.1%) were tested regarding their effects in case of strong but short time pH and temperature stress the growth of cucumber plants. There are a strong correlation between green biomass of treated cucumber plants and their root mass. It can be assumed that one of the effects of stress prevention through the biostimulators is primarily based on increasing root growth

Effect of Light Intensity and Spectra on Inorganic Constituents in Vietnamese Coriander (Persicaria odorata (Lour.) Soják)

The article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.With the aim of optimizing resources in regional production of nutritive valuable leafy vegetables, this study was conducted to obtain more knowledge regarding the interdependencies between light conditions and accumulation of inorganic constituents. The test plant, P. odorata, was cultivated in a climate chamber with fluorescent tubes as the main light source and daylight integrals (DLI) varying between 4.68 and 9.06 mol·m−2·day−1. The average DLI in greenhouse experiments was 41.55 mol·m−2·day−1. Light conditions were modified using additional LEDs (443, 515, and 629 nm) or by covering the plants with photoselective plastic films, leading to a lower DLI and modified light spectrum, especially by reducing the green spectral range. Contents of nitrate, phosphorus, potassium, magnesium, calcium, and iron, biomass accumulation, and water content were analyzed. In terms of particular light modifications, additional green (515 nm) and red (629 nm) LEDs showed reducing effects on nitrate content at both cultivation locations. Other inorganic constituents were affected differently depending on cultivation location. However, the calculation of average partial correlation coefficients enabled a more general statement. Increasing DLI correlated positively with contents of magnesium, nitrate, and potassium but negatively with contents of calcium and iron. Additionally, nitrate content correlated positively with the spectral range of 651–700 nm but negatively with the R:FR ratio. Consequently, a general recommendation related to the light conditions is not possible, as inorganic constituents were affected differently. Nevertheless, as the nitrate content in leafy vegetables is of high concern and was reduced by higher shares of green or red light, this might be one way to regulate nitrate content in leafy vegetables.Peer Reviewe

Miocene precipitation in Europe: Temporal trends and spatial gradients

It is known from present-day climates that both temporal and spatialvariations in precipitation can be more pronounced than those intemperature and thus influence ecosystems and human society in moresubstantial way. However, very little is known about such variations inthe past. Here we present an analysis of 206 palaeoprecipitation datafrom two twelve million year long proxy records of precipitation forSouthwest (Calatayud-Teruel basin) and Central Europe (Western andCentral Paratethys), spanning the late Early and Middle to Late Miocene(17.8-5.3 Ma) at a temporal resolution of about 80 kyr and 200 kyr,respectively. The estimates of precipitation are based on theecophysiological structure of herpetological assemblages. The resultsshow that precipitation variations in both regions have large amplitudesduring the Miocene with comparable temporal trends at longer timescales. With locally 300 mm up to more than 1000 mm more rainfall peryear than present, the early Langhian and the Tortonian were relativelywet periods, whereas the late Langhian and late Serravallian wererelatively dry, with up to 300 to 500 mm less precipitation thanpresent. The most humid time intervals were the early and middleTortonian washhouse climate periods. Overall, our data suggest that thelatitudinal precipitation gradient in Europe from the Middle to LateMiocene were highly variable, with a general tendency towards a reducedgradient relative to present day values. The gradient decreases duringcooling periods and increases during warming periods, similar to resultsfrom simulations of future climate change. Interestingly, theprecipitation gradient was reversed during the second washhouse climateperiod and the Early Messinian, which may have causes a negativehydrologic balance in the Eastern Paratethys during the latter time.Yet, our reconstructed gradient curve shows no direct correlation withthe global temperature signal from oxygen isotopes, which implies anon-linear regional response. Our results further suggest that majorfluctuations in the precipitation gradient can be responsible for shiftsin ecosystem distribution, and particularly, for faunal turnover inSouth Western Europe

Three soil bacterial communities from an archaeological excavation site of an ancient coal mine near Bennstedt (Germany) characterized by 16S r-RNA sequencing

This metagenomics investigation of three closely adjacent sampling sites from an archaeological excavation of a pre-industrial coal mining exploration shaft provides detailed information on the composition of the local soil bacterial communities. The observed significant differences between the samples, reflected in the 16S r-RNA analyses, were consistent with the archaeologically observed situation distinguishing the coal seam, the rapidly deposited bright sediment inside an exploration shaft, and the topsoil sediment. In general, the soils were characterized by a dominance of Proteobacteria , Actinobacteria , Acidobacteria , and Archaea , whereas the coal seam was characterized by the highest proportion of Proteobacteria ; the topsoil was characterized by very high proportions of Archaea —in particular, Nitrosotaleaceae —and Acidobacteria, mainly of Subgroup 2. Interestingly, the samples of the fast-deposited bright sediment showed a rank function of OTU abundances with disproportional values in the lower abundance range. This could be interpreted as a reflection of the rapid redeposition of soil material during the refilling of the exploration shaft in the composition of the soil bacterial community. This interpretation is supported by the observation of a comparatively high proportion of reads relating to bacteria known to be alkaliphilic in this soil material. In summary, these investigations confirm that metagenomic analyses of soil material from archaeological excavations can provide valuable information about the local soil bacterial communities and the historical human impacts on them