Quantifying moisture and roughness with Support Vector Machines improves spectroscopic soil organic carbon prediction

The challenges of Vis‐NIR spectroscopy are permanent soil surface variations of moisture and roughness. Both disturbance factors reduce the prediction accuracy of soil organic carbon (SOC) significantly. For improved SOC prediction, both disturbance effects have to be determined from Vis‐NIR spectra, which is especially challenging for roughness. Thus, an approach for roughness quantification under varying moisture and its impact on SOC assessment using Support Vector Machines is presented here.     

The Fusarium graminearum genome reveals a link between localized polymorphism and pathogen specialization

We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts.     

Genetic conservation of South African wattled cranes

The wattled crane (Grus carunculatus), a species highly dependent on wetlands, is the largest and rarest of the six African crane species. The once vast range of the wattled crane now consists of only three disjunct populations. The South African population has shown dramatic declines and supplementation of this population using eggs from south-central Africa has been proposed. The objectives of this study were to compare levels of genetic variation in South African and south-central African populations to determine if such supplementation is needed, and if so, whether the south-central African populations represent a genetically similar source for supplementation. We surveyed genetic variation in samples from South Africa, Zimbabwe, and Botswana using 12 microsatellite DNA loci and a 400-bp fragment of the mitochondrial D-loop. Samples from Zimbabwe and Botswana were deemed genetically similar and pooled to increase sample size. Subsequent analyses indicate that the pooled south-central and South African populations show differentiation in microsatellite DNA genotypes, as well as mitochondrial DNA. As the results from both genetic markers indicate genetic isolation, these populations should be managed as separate entities. As no indication was seen from either microsatellite or mtDNA data that significant loss of genetic diversity has occurred within South African wattled cranes, supplementation from outside populations may not be necessary at this time.     

Bestand,Umwandlung und Neubildung von Tonmineralen in küstennahen Sedimenten der Nordsee

Content, Transformation and Neoformation of Clay Minerals in near shore Sediments of the North Sea From literature and our own results, approximate quantitative values are given on the mineral content of clay and silt fractions of marine sediments from the Wadden Sea. Besides this, the extent of clay mineral transformation and neoformation in a marine environment is discussed. According to our knowledge, the extent of clay mineral transformation and neoformation must be unimportant because the sea water and pore solution of the sediments seems to be - with the exception of a small Mg-surplus — something like an equilibrium solution for three-and fourlayer minerals, which neither favors a considerable base fixation nor base release. Therefore illite neoformation during halmyrolysis or early diagenesis seems to be impossible because of unfavourable relations of potassium to all other cations in the sea water. Obviously the neoformation of illite is connected with later diagenesis. The processes of clay mineral neoformation in a marine evironment are probably restricted to the formation of amorphous (Mg-) Fe-Si-particles, which may be first steps in the formation of chamosites, chlorites or smectites.     

Retention of Ni,Zn and Cd by Si-associated goethite

Synthetic goethite used to study the effects of reaction time and temperature on the pH-dependent sorption of Ni, Zn and Cd was associated with amorphous silica. Ni interacted with dissolved Si and formed a Ni/Si precipitate on the goethite surface. Individual metals added at a concentration of 0.5 μmol g^?1 and sorbed during a reaction period of 504 hours (21 days) at 35°C were extracted by 0.7 M HNO₃ for 14 days. At the end of this period 11,28 and 40 percent of Ni, Cd and Zn, respectively, were not extracted whereas 20 percent of the total Fe content of the goethite and 39 percent of the associated Si were dissolved. During the sorption process metals became immobilized in the goethite particles. This effect can be related to a diffusion of metal ions into micropores. A total mobilization of sorbed metals can only be achieved by a complete dissolution of the goethite. The strong fixation of Ni, Zn and Cd by goethite suggests that additions of this Fe oxide could be used to ameliorate highly contaminated sludges or soils.     

Einfluß einiger Klima- und Anbaufaktoren auf die Ertragsbildung der Reissorte ‘IR-8’ in Cuba II. Standweite und CO2-Assimilation

Zusammenfassung Infrarot-Gasanalyse bei der Reissorte IR-8 in Cuba bestätigte deren starke Heterogenität in der Photosynthesekapazität: Trotz gleicher Beleuchtungsstärke übertrifft die CO₂- Assimilation (je Blattflächeneinheit) in den obersten Blättern um ein Mehrfaches die der unteren Blätter.Im Pflanzenbestand übernehmen die obersten, gut mit Licht versorgten Blätter den Hauptanteil an der Stoffproduktion. Die steil aufgerichteten Fahnenblätter werden auch im dichten Bestand nicht gegenseitig beschattet und behalten ihre Photosynthese-Aktivität fast unvermindert bis zur Kornreife bei. Unterschiedliche Standweite hatte keinen Einfluß auf die einheitliche CO₂-Assimilation der Fahnenblätter.Starke Bewölkung und Regen können die Netto-Assimilation bis auf den Lichtkompensationspunkt senken und teilweise zu negativer Stoffbilanz in den Blättern führen.

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Effect of some climatic and agricultural factors on yield formation by the rice variety IR-8 in Cuba. II. Population density and nitrogen fertilization

Summary Infrared gas analysis with the rice variety IR-8 in Cuba confirmed the strong heterogeneity of photosynthesis; With equal light intensity, CO₂, net assimilation (per unit leaf area) proved to be much higher in the upper leaves than in the lower ones.Within the rice population, the upper leaves, well provided with light energy, assume the main share for dry matter production. Due to their upright position, the flag-leaves maintain high photosynthetic rates up to grain maturity, without mutual shading. Different levels of population density did not affect their uniform assimilation rate.Heavy clouds and rainfall may diminish net assimilation down to the light compensation point, and even may cause negative balance in dry matter production of the leaves.

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IR-8 . II. CO₂

IR-8 : CO₂ ( ) , , . , , . , , . CO₂ . CO₂ () .

     

Einfluß einiger Klima- und Anbaufaktoren auf die Ertragsbildung der Reissorte ‘IR-8’ in Cuba III. Klimaverhältnisse

Ohne Zusammenfassung

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Effect of some climatic and agricultural factors on yield formation by the rice variety IR-8 in Cuba. III. Climatic conditions. With 27 Figures

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Tree Species Diversity in Community Managed and National Park Forests in the Mid-Hills of Central Nepal

Community forestry is expanding in developing countries but there is limited knowledge of, and contradictory findings about, its contribution to biodiversity conservation. This study aims at increasing the understanding of tree species diversity in community forests compared to National Parks. A forest inventory was carried out in four community forests and one National Park in the mid-hills of central Nepal. The study found that community forestry has contributed to high tree species diversity where forest management communities have interests in multiple species, but most community forests are moving toward promoting limited timber yielding species that have high economic value. Linking community forestry with economic incentives for conserving multiple tree species could therefore be a strategy to conserve biodiversity outside of protected areas.     

Synthesis and Antiproliferative Activity of 2,5-bis(3′-Indolyl)pyrroles,Analogues of the Marine Alkaloid Nortopsentin

2,5-bis(3′-Indolyl)pyrroles, analogues of the marine alkaloid nortopsentin, were conveniently prepared through a three step procedure in good overall yields. Derivatives 1a and 1b exhibited concentration-dependent antitumor activity towards a panel of 42 human tumor cell lines with mean IC₅₀ values of 1.54 μM and 0.67 μM, respectively. Investigating human tumor xenografts in an ex-vivo clonogenic assay revealed selective antitumor activity, whereas sensitive tumor models were scattered among various tumor histotypes.