Is there reproductive diapause in the winterform of pear psylla Cacopsyla bidens?

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Förster Energy Transfer in the Vicinity of Two Metallic Nanospheres (Dimer)

We present a detailed theoretical analysis of the Förster energy transfer process when a pair of molecules (donor and acceptor) is located nearby a cluster of two metallic nanospheres (dimer). We consider the case in which plasmonic resonances are within the overlap between the donor emission and acceptor absorption spectra, as well as the case that excludes such resonances from the aforementioned spectral overlap. Moreover, we explore the dependence of the Förster energy transfer rate on different dimer configurations (size and separation of nanospheres) and several dipole orientations of molecules. The dimer perturbs strongly the Förster energy transfer rate when plasmons are excited, donor dipole is oriented along the longitudinal axis of the dimer, and the radii of nanospheres and the sphere-gap distance are on the order of a few nanometers. In case of plasmonic excitation, the Förster energy transfer rate is degraded as the sphere-gap distance and size of the nanoparticles increase due to the dephasing of electronic motion arising from ohmic losses of metal. Also, we study the Förster efficiency influenced by the dimer, finding that the high efficiency region (delimited by the Förster radius curve) is reduced as a consequence of significant enhancement of the direct donor decay rate. Our study could impact applications that involve Förster energy transfer.     

Species of the genus Mastrus Förster (Hymenoptera, Ichneumonidae) of China with descriptions of two new species parasitizing sawflies (Hymenoptera)

Four species of Mastrus Förster, 1869 are reported from China. Two, Mastrus nigrus Sheng & Zeng, sp. n. reared from Arge pullata (Zaddach) and Mastrus rugotergalis Sheng & Zeng, sp. n. reared from Diprion jingyuanensis Xiao & Zhang, are new to science. One, Mastrus deminuens (Hartig, 1838), is a parasitoid of Pachynematus itoi Okutani. A key to species of Mastrus Förster known in China is provided.     

Förster Resonance Energy Transfer Between Molecules in the Vicinity of Graphene-Coated Nanoparticles

The recent demonstration of the plasmonic-enhanced Förster resonance energy transfer (FRET) between two molecules in the vicinity of planar graphene monolayers is further investigated using graphene-coated nanoparticles (GNP). Due to the flexibility of these nanostructures in terms of their geometric (size) and dielectric (e.g., core material) properties, greater tunability of the FRET enhancement can be achieved employing the localized surface plasmons. It is found that while the typical characteristic graphene plasmonic enhancements are manifested from using these GNPs, even higher enhancements can be possible via doping and manipulating the core materials. In addition, the broadband characteristics are further expanded by the closely spaced multipolar plasmon resonances of the GNPs.     

First record of the genus Phradis Förster (Hymenoptera, Ichneumonidae, Tersilochinae) from the Neotropical Region

One new species of the genus Phradis, Phradis peruvianussp. n., from the mountainous part of Peruvian Amazonia, is described and illustrated. This is the first record of the genus from South America and the Neotropical region.     

Simulation Study of the Effect of Surface Plasmon Coupling on Förster Resonance Energy Transfer Behavior

Plasmonics - The effect of surface plasmon (SP) coupling of an Ag sphere on the behavior of the Förster resonance energy transfer (FRET) from a donor dipole into an acceptor nearby is...     

A review of the genera Gnathochorisis F?rster and Symplecis F?rster of South Korea,with notes on Korean orthocentrines (Hymenoptera,Ichneumonidae, Orthocentrinae)

Two genera of Korean Orthocentrinae, Gnathochorisis and Symplecis, are reviewed, and keys to species of these genera are provided here. Two new species, Gnathochorisisfuscipes Humala & Lee, sp. n. and Gnathochorisiskoreensis Humala & Lee, sp. n. are described from South Korea. The current state of the taxonomy of Eastern Palaearctic orthocentrines is briefly discussed.     

Analysis of Nucleosome Structure in Polyacrylamide Gel by the Förster Resonance Energy Transfer Method

A technique for analyzing the structure of (Cy3, Cy5)-labeled nucleosomes in polyacrylamide gel after electrophoresis under native conditions was developed based on the Förster resonance energy transfer (FRET) effect. It has been shown that the correct application of this technique requires monitoring of nonspecific intermolecular FRET and fluorescence reabsorption. A comparative analysis of the results of the FRET measurements of two types of nucleosomes and their complexes with yeast protein FACT was performed, which confirmed the similarity of the structural features of nucleosomes detected in the gel and in aqueous solution. Application of FRET analysis in combination with electrophoresis makes it possible not only to separate, visualize components of a complex mixture, and to evaluate their relative content but also to characterize the structural differences between these complexes in situ.     

A new species of the genus Disogmus Förster (Hymenoptera, Proctotrupoidea, Proctotrupidae) from the Eocene Rovno amber

Disogmus rasnitsyni Kolyada & Perkovsky, sp. n. is described from a fossil inclusion of Late Eocene amber (Ukraine). The new species is most similar to Disogmus basalis (Thomson, 1857), in particular, in the shape of the tyloids and the general shortening of the segments of antennae, but distinctly differs from it and the other species of the genus by having tyloids on flagellar segments 2-4 compared to 3-6 and 4-7 in other species.     

Correlating calcium binding, Förster resonance energy transfer, and conformational change in the biosensor TN-XXL

Genetically encoded calcium indicators have become instrumental in imaging signaling in complex tissues and neuronal circuits in vivo. Despite their importance, structure-function relationships of these sensors often remain largely uncharacterized due to their artificial and multimodular composition. Here, we describe a combination of protein engineering and kinetic, spectroscopic, and biophysical analysis of the Förster resonance energy transfer (FRET)-based calcium biosensor TN-XXL. Using fluorescence spectroscopy of engineered tyrosines, we show that two of the four calcium binding EF-hands dominate the FRET output of TN-XXL and that local conformational changes of these hands match the kinetics of FRET change. Using small-angle x-ray scattering and NMR spectroscopy, we show that TN-XXL changes from a flexible elongated to a rigid globular shape upon binding calcium, thus resulting in FRET signal output. Furthermore, we compare calcium titrations using fluorescence lifetime spectroscopy with the ratiometric approach and investigate potential non-FRET effects that may affect the fluorophores. Thus, our data characterize the biophysics of TN-XXL in detail and may form a basis for further rational engineering of FRET-based biosensors.     

A quantitative approach to the evaluation of the morphological variability of two echinostomes, Echinostoma miyagawai Ishii, 1932 and E. revolutum (Frölich, 1802), from Europe

A comparative morphometric analysis was conducted on two European species of Echinostoma in order to examine the degree of the variability in the metrical characteristics of the adults and to assess their value in discriminating species. Adult E. miyagawai and E. revolutum, obtained experimentally, were compared using univariate and multivariate statistical analyses of 35 and 25 metrical characters, respectively. All subsets of worms of different ages represented homogeneous samples with respect to their morphometric characteristics; however, univariate analyses revealed significant differences in 22 and 23 variables between the corresponding age subsets of the two species, and it was found that the different allometric growth patterns contribute to this. The variables, body width at the posterior border of the ventral sucker, pharynx length and width, ovary length, testes length and width and length of the pre-ovarian region, exhibited isometric or positive allometric growth in E. miyagawai and negative allometry in E. revolutum. A cluster analysis based on 61 specimens and 25 variables separated E. revolutum and E. miyagawai unambiguously, producing an exact ordering of the specimens with respect to their identity and age. A forward stepwise discriminant analysis identified five variables (body width at the posterior border of ventral sucker, head collar width, length of oesophagus, width of ventral sucker and length of the pre-ovarian region) which yielded a 100% accurate classification of the two species. We suggest, therefore, that the morphometric characteristics of the adult worms should be used in studies attempting the identification of species or isolates of Echinostoma spp. More comparative data need to be gathered in order that the species boundaries within the revolutum group be defined more accurately.     

Effect of enhanced Renilla luciferase and fluorescent protein variants on the Förster distance of Bioluminescence resonance energy transfer (BRET)

Bioluminescence resonance energy transfer (BRET) is an important tool for monitoring macromolecular interactions and is useful as a transduction technique for biosensor development. Förster distance (R₀), the intermolecular separation characterized by 50% of the maximum possible energy transfer, is a critical BRET parameter. R₀ provides a means of linking measured changes in BRET ratio to a physical dimension scale and allows estimation of the range of distances that can be measured by any donor–acceptor pair. The sensitivity of BRET assays has recently been improved by introduction of new BRET components, RLuc2, RLuc8 and Venus with improved quantum yields, stability and brightness. We determined R₀ for BRET¹ systems incorporating novel RLuc variants RLuc2 or RLuc8, in combination with Venus, as 5.68 or 5.55 nm respectively. These values were approximately 25% higher than the R₀ of the original BRET¹ system. R₀ for BRET² systems combining green fluorescent proteins (GFP²) with RLuc2 or RLuc8 variants was 7.67 or 8.15 nm, i.e. only 2–9% greater than the original BRET² system despite being ～30-fold brighter.     

Modelling the effect of environmental factors on the “trade-off” between growth and defensive compounds in young apple trees

The allocation of plant internal resources to growth processes (primary metabolism) and to defensive compounds (secondary metabolism) is determined by plant internal competition for common substrates and energy. In order to contribute to the discussion about environmental impacts on this trade-off between demands for growth and defence, we extended a complex plant growth model to simulate the formation of defensive compounds on the whole plant level, depending on the dynamics of the environmental conditions light, nutrients and water. In this paper, we present and apply the model to simulate the effects of different N fertilizer applications on growth and resistance of young apple trees (cv Golden Delicious). The results show that model predictions are able to describe the observed relation between growth rate and phenylpropanoid concentrations in young leaves of apple trees, and can assist in the interpretation of experimental findings. Finally, we estimate costs and benefits of investment into defence in a scenario, in which an attack by the leaf pathogen Venturia inaequalis is simulated.     

Characterization of Förster resonance energy transfer in a botulinum neurotoxin protease assay

Using the cell-permeable, radioiodinated, irreversible inhibitor BIL-DMK, we probed active cysteine cathepsins in blood. Incubation of the probe in human whole blood followed by separation of white blood cells by dextran sedimentation led to the labeling of one major band at 24 kDa. Two-dimensional gel electrophoresis showed that the band resolved in a single protein spot and corresponded to cathepsin S based on its molecular mass, isoelectric point, and Western blot analysis using anti-human cathepsin S antibodies. Cathepsin S activity in human whole blood was dependent on the time of blood collection, suggesting that cathepsin S activity is subject to circadian variations. Separation of white blood cell populations using a magnetic cell sorter and further characterization by FACS (fluorescent-activated cell sorting) analysis demonstrated that the majority of active cathepsin S resided in the monocyte and neutrophil populations, whereas on a cell basis cathepsin S activity in granulocytes is 10-fold lower than that in monocytes. A whole blood cathepsin S assay was developed and used to measure cathepsin S inhibition in both in vitro and ex vivo conditions. To determine the correlation between the in vitro and ex vivo assays, a reversible cathepsin S inhibitor was dosed intravenously to a rhesus monkey. The inhibitor concentration required to inhibit 50% of the cathepsin S activity ex vivo correlated well with the concentration required to inhibit the enzyme in rhesus monkey whole blood in vitro. The results reported here demonstrate the utility of the activity-based probe BIL-DMK for the ex vivo assessment of cathepsin S inhibition.     

Elastic deformations of the rotary double motor of single F(o)F(1)-ATP synthases detected in real time by Förster resonance energy transfer

Elastic conformational changes of the protein backbone are essential for catalytic activities of enzymes. To follow relative movements within the protein, F?rster-type resonance energy transfer (FRET) between two specifically attached fluorophores can be applied. FRET provides a precise ruler between 3 and 8nm with subnanometer resolution. Corresponding submillisecond time resolution is sufficient to identify conformational changes in FRET time trajectories. Analyzing single enzymes circumvents the need for synchronization of various conformations. F(O)F(1)-ATP synthase is a rotary double motor which catalyzes the synthesis of adenosine triphosphate (ATP). A proton-driven 10-stepped rotary F(O) motor in the Escherichia coli enzyme is connected to a 3-stepped F(1) motor, where ATP is synthesized. To operate the double motor with a mismatch of step sizes smoothly, elastic deformations within the rotor parts have been proposed by W. Junge and coworkers. Here we extend a single-molecule FRET approach to observe both rotary motors simultaneously in individual F(O)F(1)-ATP synthases at work. We labeled this enzyme with two fluorophores specifically, that is, on the ε- and c-subunits of the two rotors. Alternating laser excitation was used to select the FRET-labeled enzymes. FRET changes indicated associated transient twisting within the rotors of single enzyme molecules during ATP hydrolysis and ATP synthesis. Supported by Monte Carlo simulations of the FRET experiments, these studies reveal that the rotor twisting is greater than 36° and is largely suppressed in the presence of the rotation inhibitor DCCD. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).     

Endocrine control of oögenesis in the housefly,Musca domestica vicina

The endocrine system involved in the control of oögenesis in the housefly, Musca domestica vicina, was investigated. Allatectomy, decapitation, and starvation of newly emerged females resulted in inhibition of oögenesis, showing a close relationship between enlargement of the corpus allatum and growth of follicles during the first oögenesis. Histological observation of sexually matured females showed active secretion of the corpus allatum and the medial neurosecretory cells of pars intercerebralis. Topical application of juvenile hormone analogues (JHA) to the allatectomized fly induced the growth of ovary, and critical doses of methoprene and methyl-7, 11-diethyl-juvenate for the maturation of the ovary were determined. JHA stimulated initiationof oögenesis in the starved or decapitated flies as well as vitellogenesis in the sugar-fed one; subsequently it was found that juvenile hormone acted not only as a gonadotropin but also as a regulator of vitellogenesis. Furthermore, JHA stimulated cell lysis in pupal fat body of female flies, indicating a possible influence of juvenile hormone upon the process of releasing vitellogenin.     

Description of new species of the genus Ctenochira Förster, 1855 (hymenoptera,ichneumonidae: Tryphoninae) from the Eurasian Subarctic subzone and Siberia,with remarks on the Ichneumonid fauna of the Chukchi Peninsula

13 new species of Ctenochira (Hymenoptera, Ichneumonidae, Tryphoninae) from the Eurasian Subarctic subzone and Siberia are described: C. albosignata sp. n., C. anabar sp. n., C. epipleuralis sp. n., C. gracilicornis sp. n., C. hyperborea sp. n., C. kerzhneri sp. n., C. laticauda sp. n., C. minuta sp. n., C. nigronitens sp. n., C. pallistigma sp. n., C. tixi sp. n., C. trochanterata sp. n., and C. uzon sp. n. A key to the Subarctic and northern Siberian species is given. Quantitative occurrence of different ichneumonid subfamilies in the Subarctic subzone is considered based on analysis of 827 specimens of ichneumonids collected in yellow plates in the Chukchi Autonomous Area in July 2012. Idiobiont (polyphagous) subfamilies (36.5%): Cryptinae, 294 spms. (35.5%); Pimplinae, 8 (1%). Koinobiont parasitoids, 10 subfamilies (63.5%): parasitoids of Symphyta, 313 spms. (37.9%): Tryphoninae, 225 (27.2%); Adelognathinae, 14 (1.7%); Ctenopelmatinae, 59 (7.2%); Campopleginae (Olesicampe; Lathrostizus), 15 (1.8%); parasitoids of Diptera, 169 spms. (20.5%): Diplazontinae, 8 (1%); Orthocentrinae s. l., 161 (19.5%); parasitoids of Lepidoptera, 29 spms. (3.5%): Campopleginae (part), 18 (2.2%) (Campoletis; Hyposoter; Tranosema; Diadegma; etc.); Ichneumoninae, 2 (0.2%); Banchinae, 3 (0.4%) (Glypta; Lissonota); Metopiinae, 6 (0.7%) (Exochus); parasitoids of Coleoptera (0.3%): Tersilochinae, 3 spms. (Barycnemis); hyperparasitoids (1.3%): Mesochorinae, 11 spms.     

Two new species of genus Ateleute Förster (Hymenoptera, Ichneumonidae, Cryptinae) with a key to the Oriental species

Three species of Ateleute Förster 1869 belonging to the tribe Cryptini of the subfamily Cryptinae (Hymenoptera, Ichneumonidae), collected from Jiangxi Province, China, are reported, of which two are new for science: Ateleute ferruginea Sheng, Broad & Sun, sp. n. and AAteleute zixiensis Sheng, Broad & Sun, sp. n. One, AAteleute densistriata (Uchida, 1955), was previously known from China and Japan. A key to the species of genus Ateleute known in the Oriental Region is provided.