Original articles - Simulations and parameter estimation of a trap-insect model using a finite element approach
Contributors: Roumen Anguelov, Claire Dufourd, Yves Dumont
... Estimating pest population size is of utmost importance in biological control. However field experiments can be difficult and expensive to conduct, with no guarantee that useable results will be produced. In this context, the development of mathematical models and numerical tools is crucial to improve the field experiments by suggesting relevant data which can be used to estimate parameters related to the pest’s biology and to the traps (e.g. duration of the experiments, distance of the releases, etc.). Here we develop a trap-insect model (TIM), based on coupled partial differential equations. The model is studied theoretically and a finite element algorithm is developed and implemented. A protocol for parameter estimation is also proposed and tested, with various data. Among other results, we show that entomological knowledge is absolutely necessary for efficient estimation of parameters, in particular population size.
Scottish early Holocene vegetation dynamics based on pollen and tephra records from Inverlair and Loch Etteridge, Inverness-shire
Contributors: Thomas J. Kelly, Mark Hardiman, Michael Lovelady, J. John Lowe, Ian P. Matthews, Simon P.E. Blockley
... This paper presents the results of an investigation of early Holocene cryptotephra layers recovered from sediments in two kettle-hole basins at Inverlair (Glen Spean) and Loch Etteridge (Glen Fernisdale). Electron probe micro-analysis (EPMA) of shards from two cryptotephra layers revealed that the uppermost layer in both sequences has a composition similar to the An Druim tephra, first reported from a site in Northern Scotland. We present evidence that distinguishes the An Druim from the chemically very similar early Holocene Ashik tephra. The lowermost layer at Inverlair matches the composition of the Askja-S tephra found in the Faroe Islands, Ireland, Sweden, Germany and Switzerland. This is the first published record of the Askja-S tephra from mainland Scotland. As at other sites, the Askja-S seems to mark a short-lived climatic deterioration, most likely the Pre-Boreal Oscillation: at Inverlair it occurs just above an oscillation represented by a reduction in LOI values and in the abundance of Betula pollen, and by a peak in Juniperus pollen. The lowermost layer at Loch Etteridge has a Katla-type chemistry and extends through the upper part of the Loch Lomond (Younger Dryas/GS-1) Stadial to the Stadial/Holocene transition; it may represent a composite layer which merges the Vedde and Abernethy tephras. One of the key conclusions is that the glacial-melt deposits in the vicinity of Inverlair (kames and kame terraces) were ice-free by c. 10.83ka (the age of the Askja-S), providing a limiting age on the disappearance of LLR ice in Glen Spean.
Contributors: Robert J. Le Roy, Asen Pashov
... This paper describes program betaFIT, which performs least-squares fits of sets of one-dimensional (or radial) potential function values to four different types of sophisticated analytic potential energy functional forms. These families of potential energy functions are: the Expanded Morse Oscillator (EMO) potential [J Mol Spectrosc 1999;194:197], the Morse/Long-Range (MLR) potential [Mol Phys 2007;105:663], the Double Exponential/Long-Range (DELR) potential [J Chem Phys 2003;119:7398], and the “Generalized Potential Energy Function (GPEF)” form introduced by Šurkus et al. [Chem Phys Lett 1984;105:291], which includes a wide variety of polynomial potentials, such as the Dunham [Phys Rev 1932;41:713], Simons–Parr–Finlan [J Chem Phys 1973;59:3229], and Ogilvie–Tipping [Proc R Soc A 1991;378:287] polynomials, as special cases. This code will be useful for providing the realistic sets of potential function shape parameters that are required to initiate direct fits of selected analytic potential functions to experimental data, and for providing better analytical representations of sets of ab initio results.
Contributors: Yadaiah Ch, S.K. Goswami, Debashis Chatterjee
... Effect of network reconfiguration on power quality issues of distribution system has been investigated. The problem of network reconfiguration is reformulated with an objective to improve the power quality of the distribution system. Along with the traditional objective of loss minimization, power quality related objectives such as minimization of harmonic distortion of the voltage waveform, minimization of voltage unbalances at the nodes and maximization of sag voltages are identified as the objectives of reconfiguration. Branch exchange technique has been used to establish each of the objectives. The problem has also been formulated as a multi-objective optimization problem. The multiple objectives are, however, incorporated into a single objective using weighting multipliers and branch exchange technique has been judicially applied to take care of all the objectives. It is found that network reconfiguration can be used as an effective tool to improve the power quality of distribution system. Besides, the distributed energy sources also have great impacts on distribution network, as their size and locations are found to have great importance on the power loss, voltage sag, voltage harmonic distortion and unbalance. The effectiveness of the network reconfiguration on power quality issues have been studied on 25-bus network and IEEE 33-bus network with and without presence of distributed generation and VAr sources.
Contributors: Ming Bai, Rolf Georg Beutel, Klaus-Dieter Klass, Weiwei Zhang, Xingke Yang, Benjamin Wipfler
... A new insect species (†Alienopterus brachyelytrus Bai, Beutel, Klass, Wipfler et Zhang gen. et sp. nov.) of a new order and family is described, based on a single male embedded in Cretaceous Burmese amber (ca. 99Ma). Unusual characters are shortened forewings combined with fully developed, operational hindwings, similar as in Dermaptera, and specialized attachment pads otherwise only found in mantophasmatodeans (heelwalkers). A cladistic analysis suggests a placement as sister to Mantodea, supported by a profemoral brush and other characters. The male genitalia show the same pattern in both groups. Specialized features are the unusual flight apparatus, attachment structures adapted for locomotion on leaves, and a dense profemoral setation suitable for catching small prey. †Alienopterus was apparently able to fly and likely a predator of small arthropods in bushes or trees. An impressive radiation of Mantodea started in similar habitats at least 35Ma later in the early Cenozoic. In contrast, †Alienopterus was an evolutionary dead end in the roach–mantis transition zone.
One taxon does not fit all: Herb-layer diversity and stand structural complexity are weak predictors of biodiversity in Fagus sylvatica forests
Contributors: F.M. Sabatini, S. Burrascano, M.M. Azzella, A. Barbati, S. De Paulis, D. Di Santo, L. Facioni, D. Giuliarelli, F. Lombardi, O. Maggi
... Since adequate information on the distribution of biodiversity is hardly achievable, biodiversity indicators are necessary to support the management of ecosystems. These surrogates assume that either some habitat features, or the biodiversity patterns observed in a well-known taxon, can be used as a proxy of the diversity of one or more target taxa. Nevertheless, at least for certain taxa, the validity of this assumption has not yet been sufficiently demonstrated.
Contributors: Michael Sundue, George Poinar Jr.
... We report the second record of a grammitid fern from Dominican amber. The fossil comprises a single fertile pinna with excellent preservation, thus allowing a clear view of unaltered morphological characters. Venation, indument, and sori match the protologue of the previously described species from Dominican amber, Grammitis succinea L. D. Gómez, so we assign our fossil to that species. Characters of both specimens of G. succinea are sufficient to place it within the grammitid clade of the Polypodiaceae. However, it does not agree with Grammitis as it is currently circumscribed. We explore possible relationships between the fossil and other extant grammitid genera through Principal Coordinates Ordination (PCOa) of 109 morphological characters and through phylogenetic analysis of combined morphological and plastid DNA sequence data. Character combinations found in the fossil are inconsistent with those of any extant genus and our PCOa analysis did not suggest a clear affinity with any extant genus. This uncertainty is reflected in the results of our phylogenetic analyses, which find multiple most-parsimonious positions for the fossil within the grammitid clade. Based on these results, we suggest that the fossil belongs to an early divergent lineage of grammitid ferns, and cannot be assigned to any extant genus. Consequently, we place both specimens in a newly described fossil genus, Polymniopteris, and make a new combination for G. succinea within it. Because the type of G. succinea cannot be located, we designate the present specimen a neotype.
Contributors: Filipe J. Marques, Florence Loingeville
... The Generalized Gamma distribution is an important distribution in Statistics since it has as particular cases many well known and important distributions and also due to its very interesting modeling properties, which makes it an attractive tool. The distribution of the product of independent Generalized Gamma distributions is investigated. Most of the results available for this distribution are based on Meijer-G or H functions which may still be very difficult to handle. Therefore, near-exact distributions which are based on the Generalized Near-Integer Gamma distribution and which have density and cumulative distribution functions easily implementable and computationally appealing are developed. Numerical studies with computationally intensive analyses are carried out to study the accuracy of these approximations in different scenarios. Also computational modules are provided for the implementation of these approximations. Finally, an example of application to quality control in microbiology is provided.
Contributors: Hongpeng Lu, Liyun Zhang, Xianming L. Han, Qingfeng Pi, Daimei Wang
... We present new CCD photometric observations of V1044 Her obtained on May 22, 23 and 24, 2015. From our data, we derived five new light curve minimum times. Combining our new results with previously available CCD light minimum times, we derived an updated ephemeris and discovered that the period of this binary system exhibits an oscillation. The cyclic variation may be caused by the light-time effect via the presence of a third body or magnetic activity cycle. We calculated the corresponding period of the third body to be 14.1 ± 1.4 years or magnetic cycle to be 12.2 ± 0.7 years. We analyzed our new asymmetric light curves to obtain photometric solutions and starspot parameters using the Wilson&Devinney program. The final results show that V1044 Her is a contact binary system with a degree of contact factor f = 3.220( ± 0.002)%.
New Spanish Late Cretaceous eusuchian reveals the synchronic and sympatric presence of two allodaposuchids
Contributors: I. Narváez, C.A. Brochu, F. Escaso, A. Pérez-García, F. Ortega
... The recently described clade Allodaposuchidae includes European eusuchian crocodyliforms restricted to the Late Cretaceous (Campanian and Maastrichtian). A new allodaposuchid crocodyliform is here described based on two specimens from the upper Campanian–lower Maastrichtian fossil site of Lo Hueco (Cuenca, Spain). This new taxon, Agaresuchus fontisensis gen. et sp. nov., is described by two complete skulls and a lower jaw associated with one of them. This new species can be distinguished unambiguously from Lohuecosuchus megadontos, the other allodaposuchid known from the same fossil site. The presence of two allodaposuchid crocodyliforms in Lo Hueco allows the recognition of the synchronic and sympatric existence of two representatives of this clade for the first time. The new genus Agaresuchus, comprises a previously described Iberian allodaposuchid species, “Allodaposuchus” subjuniperus, as Agaresuchus subjuniperus, new combination.