Seasonal growth and nitrogen distribution in grapevine leaves, shoots and grapes

Jahresverlauf des Wachstums und der Stickstoffverteilung in Blatt, Trieb und Traube von WeinrebenIn einem Ertragsrebberg wurden in regelmäßigen Abständen während des Jahres Proben von Blättern, Trieben und Trauben genommen. Davon wurden das Frisch- und Trockengewicht, die Blattfläche sowie der Wasser- und Stickstoffgehalt bestimmt. Das Wachstum wurde auf der Basis von Grad-Tagen > 10 °C (GT) dargestellt. Das Primärblatt-Wachstum konnte in zwei Phasen unterteilt werden. Die erste Phase dauerte bis zum Alter von 250 GT und war durch ein rasches Blattwachstum gekennzeichnet (0.0043 g · GT-1). Die zweite Phase wies nur eine geringe Wachstumsrate von 0.0006 g · GT-1 auf und dauerte bis zum Blattfall. Bei 250 GT war das Blatt voll entfaltet und die N-Einlagerung abgeschlossen. Die spezifische Blattfläche (m2 . g-1) fiel nach einem kurzen Anstieg mit zunehmendem Blattalter kontinuierlich ab. N- und Wasser-Gehalte nahmen im Verlaufe des Jahres ebenfalls ab. Im Spätsommer sind zwar mehr Geizblätter als Primärblätter vorhanden, die gesamte Blattfläche und -masse sowie die absolute N-Menge waren jedoch ungefähr gleich auf Haupt- und Geiztriebe verteilt. Die relative Verteilung von Trockensubstanz (TS) in Blättern und Trieben unterschied sich von der N-Verteilung. Der größte Anteil an TS war in den Trieben lokalisiert, während sich in den Blättern die größte N-Menge vorfand.

Basic conceptual structures theory

Although the theory of Conceptual Structures is over 10 years old, basic notions (like canonical graphs) are far from settled and are subject to constant extensions and reformulations. However, most of these are done in an informal way, which doesn't help in clarifying the issues involved. It is our hope that this paper will provide a first step towards the complete and rigorous account of Conceptual Structures (CS) Theory, which is needed for ongoing standardization and implementation efforts. Towards that goal, we present formal definitions of some of the central notions of CS theory (type, referent, concept, relation, conceptual graph, canonical formation rules, canon, and canonical graph) in its simplest form, i.e. no contexts nor coreference links are allowed and referents must be individuals. We thereby introduce higher-order types in order to enable the use of conceptual graphs at the metalevel, the restriction operation of the canonical formation rules is extended to make use of the relation hierarchy, we show the relationship between denotation and conformity relation, and we give a rigorous meaning to the canonical basis, among other things

Influence of the twospotted spider mite, Tetranychus urticae, on the gas exchange of Pinot noir grapevine leaves

The effect of feeding damage by the twospotted spider mite (Tetranychus urticae KOCH; Acari: Tetranychidae) on the gas exchange of grapevine leaves (Vitis vinifera L.; cv. Pinot noir) was investigated. In addition, the influence of some pesticides was studied. A significant reduction of the net CO2 assimilation, transpiration as well as stomatal and mesophyll conductance with increasing mite feeding damage were observed. At 6000 mite-days per leaf the 3rd and 9th main leaves (from the base) showed an average reduction in net CO2 assimilation of 52.2 % and 48.4 %, respectively, while the 6th leaf showed a reduction of only 21.3 %. The response of grapevine photosynthesis to mite feeding seems to depend not only on mite density and duration of feeding, but also on the phenological stage of the plant. In fact, at veraison the vines showed increased tolerance to mite feeding compared with other phenological stages. At mite infestation levels of 6000 mite-days, leaves infested with T. urticae showed, as compared to uninjured leaves, an average reduction in transpiration rate of 14.4 % to 40.8 %, depending on the leaf position. The acaricides Tetradifon and Fenbutatin-oxide and the fungicide Folpet combined with Penconazol showed no effect on the gas exchange parameters

Assessing architectural evolution: A case study

This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles, and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand, to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach

A local risk map using field observations of the Asian longhorned beetle to optimize monitoring activities

The Asian longhorned beetle Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most dangerous xylophagous pests affecting broadleaf trees in the world. Eradication programmes are undertaken in non-native regions, requiring extensive resources and involving high costs. An adapted strategy must be set up to optimize the ratio cost/probability of success. We developed a method to generate a risk index of A. glabripennis presence at a local scale, in the surrounding area of an infestation, using field observations (counts of adult insects, exit holes and infested trees). The method, mathematically based on the bivariate symmetric Laplace distribution, has thus reasonable input requirements. The output risk map is easy to interpret and can be directly used by decision-makers. We used our approach in three infestations in Switzerland. The risk map represented well the insect pressure (beetle population density). We highlighted the fact that survey boundaries, commonly chosen using constant distances from the infestation, should be selected regarding the spatial distribution of the insect pressure, to prioritize monitoring activities. The risk map provides a helpful instrument for advanced survey planning after a first overview, for example to decide which area and which host trees should be inspected for infestations

A molecular tool to identify <i>Anastatus</i> parasitoids of the brown marmorated stink bug

Globally, Anastatus species (Hymenoptera: Eupelmidae) are associated with the invasive agricultural pest Halyomorpha halys (Stal) (Hemiptera: Pentatomidae). In Europe, the polyphagous Anastatus bifasciatus (Geoffroy) is the most prevalent native egg parasitoid on H. halys eggs and is currently being tested as a candidate for augmentative biological control. Anastatus bifasciatus frequently displays behavior without oviposition, and induces additional host mortality through oviposition damage and host feeding that is not measured with offspring emergence. This exacerbates accurate assessment of parasitism and host impact, which is crucial for efficacy evaluation as well as for pre- and post-release risk assessment. To address this, a general Anastatus primer set amplifying a 318-bp fragment within the barcoding region of the cytochrome oxidase I (COI) gene was developed. When challenged with DNA of three Anastatus species -A. bifasciatus, Anastatus japonicus Ashmead, and Anastatus sp.-, five scelionid parasitoid species that might be encountered in the same host environments and 11 pentatomid host species, only Anastatus DNA was successfully amplified. When applied to eggs of the target host, H. halys, and an exemplary non-target host, Dendrolimus pini L. (Lepidoptera: Lasiocampidae), subjected to host feeding, no Anastatus amplicons were produced. Eggs of the two host species containing A. bifasciatus parasitoid stages, from 1-h-old eggs to pupae, and emerged eggs yielded Anastatus fragments. Confirmation of parasitoid presence with dissections and subsequent PCRs with the developed primer pair resulted in 95% success for 1-h-old parasitoid eggs. For both host species, field-exposed sentinel emerged eggs stored dry for 6 months, 100% of the specimens produced Anastatus amplicons. This DNA-based screening method can be used in combination with conventional methods to better interpret host-parasitoid and parasitoid-parasitoid interactions. It will help address ecological questions related to an environmentally friendly approach for the control of H. halys in invaded areas

Fast analysis of low molecular mass compounds present in snake venom: identification of ten new pyroglutamate-containing peptides.

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An overview of a systems model of cassava and cassava pests in Africa

A systems model is described for cassava, Manihot esculenta Crantz, two of its introduced herbivores, the cassava green mite (CGM), Mononychellus tanajoa (Bondar), sensu lato, and the cassava mealybug (CM), Phenacoccus manihoti Mat.-Ferr., the introduced CM parasitoid, Epidinocarsis lopezi (DeSantis) and coccinellid predator of the genus Hyperaspis. The systems model includes the effects of weather, soil nitrogen and water levels on the interactions of the system's components. The model simulates the distribution of developmental times of cohorts initated at the same time, as well as the number and biomass (energy) dynamics of all populations over time. Biomass acquisition and allocation at the population and organism subunit levels (e.g. leaves, fruit, ova) were also simulated. A common acquisition (i.e. functional response) submodel was used to estimate daily photosynthetic as well as nitrogen and water uptake rates in cassava, in addition to herbivory, parasitism and predation rates for the arthropod species. This paper presents an overview of the systems model. Simulation results for the plant under pest free conditions were compared to field data. In addition, the model was used to estimate tuber yield losses due to CM and CGM feeding, and to examine the beneficial effects of introduced CM natural enemies as measured by reductions in tuber yield losse

Representing First-Order Logic Using Graphs

Abstract. We show how edge-labelled graphs can be used to represent first-order logic formulae. This gives rise to recursively nested structures, in which each level of nesting corresponds to the negation of a set of existentials. The model is a direct generalisation of the negative application conditions used in graph rewriting, which count a single level of nesting and are thereby shown to correspond to the fragment ∃¬∃ of first-order logic. Vice versa, this generalisation may be used to strengthen the notion of application conditions. We then proceed to show how these nested models may be flattened to (sets of) plain graphs, by allowing some structure on the labels. The resulting formulae-as-graphs may form the basis of a unification of the theories of graph transformation and predicate transformation

Impacts of salvage logging on biodiversity: A meta-analysis

Logging to "salvage" economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking. A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms. A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging. By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages. Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity