A new approach to analyze the dynamic strength of eggs

The mechanical behavior of eggshell was determined in terms of average rupture force and corresponding deformation. For the experiment, we selected goose eggs (Anser anser f. domestica). Samples of eggs were compressed along their x-axis and z-axis. The effect of the loading orientation can be described in terms of the eggshell contour curvature. Two different experimental methods were used: compression between two plates (loading rates up to 5 mm/s) and the Hopkinson split pressure bar technique. This second method enables achieving loading rates up to about 17 m/s. The response of goose eggs to this high loading rate was characterized also by simultaneous measurement of the eggshell surface displacements using a laser vibrometer and by the measurement of both circumferential and meridian strains.     

Chemical defences of native European coccinellid eggs against intraguild predation by the invasive Asian coccinellid, <Emphasis Type="Italic">Harmonia axyridis</Emphasis> (Pallas)

Harmonia axyridis (Pallas) is a coccinellid of Asian origin that has recently invaded substantial parts of Europe and is suspected to affect native coccinellid populations through intraguild predation and competition for food. Previous work has shown that two species from the Calvia genus appeared to be well protected against H. axyridis predation. To deepen our understanding on chemical protection of Calvia spp. and the predation risk by H. axyridis, we tested for susceptibility and palatability of Calvia spp. and H. axyridis eggs against predation by H. axyridis neonate larvae. Results show that eggs of C. quatuordecimguttata were mostly not eaten by H. axyridis, while eggs of the congeneric C. decemguttata were found to be largely unprotected against predation by the invasive coccinellid. We also observed that H. axyridis first instars successfully cannibalized on conspecific eggs. Removing the surface chemicals from C. quatuordecimguttata eggs resulted in significantly reduced protection from being preyed upon by H. axyridis, while applying these extracts onto C. decemguttata and H. axyridis eggs resulted in increased protection against H. axyridis larvae. The importance of surface chemicals in the interactions between H. axyridis and native coccinellids was confirmed by GC–MS analysis, showing a high diversity of hydrocarbons located on the surface of C. quatuordecimguttata eggs, i.e. more than twice as many when compared to C. decemguttata. Survival of H. axyridis larvae feeding on eggs of C. quatuordecimguttata, C. decemguttata or conspecific eggs, from which surface chemicals were removed by washing them with hexane, was not different from survival on unwashed eggs.     

Biosystematic study of Berlandiera (Compositae)

Berlandiera is revised to includeB. subacaulis, B. pumila, B. texana, andB. lyrata with its varietieslyrata andmacrophylla. All species may be induced to interbreed readily, producing F₁ progeny which are vigorous but with reduced fertility. Sympatric species produce natural hybrids which are proposed here asB. Xhumilis (=B. pumila XB. subacaulis) andB. Xbetonicifolia (=B. pumila XB. texana). All taxa investigated hadn = 15 chromosomes, including new counts forB. subacaulis and all six F₁ hybrids.     

Reliability of the search for 19 common mutations in the <Emphasis Type="Italic">CFTR</Emphasis> gene in Russian cystic fibrosis patients and the calculated frequency of the disease in Russian Federation

A study of Russian cystic fibrosis (CF) patient DNA was conducted to assess the incidence frequency of 19 mutations, namely CFTRdele2,3(21kb), F508del, I507del, 1677delTA, 2143delT, 2184insA, 394delTT, 3821delT, L138ins, 604insA, 3944delGT, G542X, W1282X, N1303K, R334W, and 3849 + 10kbC > T, S1196X, 621 + 1g > t, and E92K of the CFTR gene. We also sought to determine the estimated CF frequency in Russian Federation. In addition, we determined the total information content of the approach for 19 common mutations registration in the CFTR gene, 84.6%, and the allelic frequencies of the examined mutations: three mutations were observed with a frequency exceeding 5% (F508del, 53.98%, E92K, 6.47%, CFTRdele2,3(21kb), 5.35%); other mutations were observed with frequencies ranging from 0.13 to 3.0%. The CF population carrier frequency was 1 in 38 subjects, while the predicted CF frequency was 1 in 5776 newborns.     

Rate of consumption,biological parameters,and population growth capacity of <Emphasis Type="Italic">Orius laevigatus</Emphasis> fed on <Emphasis Type="Italic">Spodoptera exigua</Emphasis>

Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) is already successfully used to control Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in protected crops. In the present work, the predatory capacity of O. laevigatus on the eggs and larvae of Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) as well as the population growth capacity of O. laevigatus fed on eggs of the noctuid were determined. Fourth and 5th instar nymphs had a greater consumption of eggs than younger ones. Females consumed more eggs than males. Only 5th instar nymphs and adults preyed on the neonatal larvae of S. exigua. The intrinsic rate of natural increase did not differ between O. laevigatus fed with S. exigua eggs and those offered eggs of the substitute host Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae). Thus, O. laevigatus is a good candidate for the biological control of S. exigua, a cosmopolitan pest of many crops.     

Preparation and Optimization of Fast-Disintegrating Tablet Containing Naratriptan Hydrochloride Using D-Optimal Mixture Design

Optimization of a lyophilized fast-disintegrating tablet (LFDT) formulation containing naratriptan hydrochloride, an antimigraine drug, was the foremost objective of the study, aiming in achieving fast headache pain relief. The Design-Expert® v10 software was used to generate formulations using D-optimal mixture design with four components: gelatin (X₁), hydrolyzed gelatin (X₂), glycine (X₃), and mannitol (X₄) of total solid material (TSM) w/w. The effect of the relative proportion of each component was determined on friability (Y₁), hardness (Y₂), and in vitro disintegration time (Y₃), which was then applied for formulation optimization. In addition, their effect on tablet porosity was determined via scanning electron microscopy (SEM). Drug-excipient interaction was evaluated using differential scanning calorimetry (DSC). A comparative dissolution study against the conventional tablets was studied. Accelerated stability study was carried out in (Al/Al) and (Al/PVC) blister packs. An in vivo pharmacokinetic study was carried out to compare the optimized formulation and the conventional tablets. The optimized formulation’s responses were 0.30%, 3.4 kg, and 6.12 s for Y₁, Y₂, and Y₃, respectively. No drug-excipient interaction was specified via DSC. The optimized formulation exhibited porous structure as determined via SEM. Dissolution study demonstrated complete dissolution within 1.5 min. Study indicated stability for 78 months in (Al/Al) blister packs. In vivo pharmacokinetic study demonstrated that C_max, AUC_last, and AUC_inf were significantly higher for the developed formulation. As well, the T_max was 1 h earlier than that of convenient tablet. An LFDT would achieve a faster onset of action for naratriptan compared to other formulations.     

Suitability of Different Prey Aphids on the Growth,Development and Reproduction of <Emphasis Type="Italic">Chrysoperla zastrowi sillemi</Emphasis> (Esben-Petersen) (Chrysopidae: Neuroptera)

The prey preference of polyphagous predator, green lacewing (Chrysoperla zastrowi sillemi (Esben-Petersen)) was evaluated against five prey aphids viz., mustard aphid (Lipaphis erysimi), green peach aphid (Myzus persicae), cabbage aphid (Brevicorynebrassicae), black bean aphid (Aphis craccivora), spirea aphid (Aphis spiraecola) of agriculture importance and compared with eggs of Corcyracephalonica (Stainton). Lacewing larvae preferred Myzus persicae most followed by Brevicorynebrassicae. The highest growth index (8.31), larval survival (94.50 %), larval weight (10.45 mg), pupal weight (8.78 mg), faster multiplication rate (0.051) and fecundity (183.4 per gravid female) of the predator were recorded on M. persicae. However, the chrysopid reared on Corcyra eggs performed best in all biological parameters and fitness, than on aphid preys. This study explores the possibilities of selecting the most suitable prey aphid species for its exploitation as supplement for mass multiplication of chrysopid during off-season or unavailability of Corcyra eggs.     

Is It Possible to Manipulate Scelionidae Wasps’ Preference to a Target Host?

Parasitoid host selection is mainly mediated by chemical cues, which can be adjusted by experience, changing their innate behavior. Therefore, this study evaluated if immature experience (pre-imaginal conditioning) on eggs and volatiles from different host eggs has influence on parasitism and chemotaxic behavior of Telenomus podisi Ashmead and/or Trissolcus basalis Wollaston (Hymenoptera: Scelionidae). Both wasp species were submitted to a multiple-choice parasitism test among Euschistus heros (Fabricius), Piezodorus guildinii (Westwood), and Nezara viridula L. (Hemiptera: Pentatomidae) (Hemiptera: Pentatomidae) egg masses. Eggs from these three stink bugs were equally offered to female parasitoids. After that, adults which emerged from each host were also exposed to parasitism in a multiple-choice test for up to an additional generation. Moreover, in olfactometer “Y,” the behavior of innate and experienced T. podisi females to volatiles from hosts’ egg extracts was tested, to study their learning and memory ability. The original host had influence on T. podisi parasitism; however, T. basalis always parasitized more N. viridula eggs independently of its last rearing host. Innate T. podisi females responded positively to E. heros and P. guildinii egg volatiles, but this behavior was not observed in N. viridula. When T. podisi females were experienced on egg volatiles from a new host, they showed significant learning and memory ability for the specific host volatile for, at least, 24 h. Experienced wasps responded positively to N. viridula and through this result we have evidences about the possibility to manipulate wasp’s preferences to a specific target host.     

Formation of a Z-pinch during electromagnetic compression of a nonquasineutral current filament

A study is made of the structure of a relativistic current filament with the azimuthal magnetic field B_θ in the range 4πn _e m _e c²?B _θ ² 4πn _i m _i c², when the plasma quasineutrality near the filament axis is violated and a narrow peak in electron density is formed there. The ion dynamics in a strong radial electric field of the filament on time scales of about several inverse ion plasma frequencies ω _pi ^?1 is investigated. The initial ion pressure prevents the ion plasma component from compression to infinitely high densities under the action of the electric field and leads to the formation of a dense hot plasma core near the axis of the Z-pinch on time scales of about a dozen ω _pi ^?1 . The compression of the ion component in the axial region gives rise to a collisionless “unloading” shock wave that propagates away from the axis and is accompanied by the vanishing of the radial ion velocity behind the shock front, the accumulation of positive charge near the axis, and the formation of a steady-state ion density profile. It is shown theoretically that ion-ion dissipation manifests itself as the destruction of the hot core of the formed Z-pinch on picosecond time scales. This may serve to explain the explosions of “hot points” in a current-carrying plasma.     

Enumeration of Viral Capsid Assembly Pathways: Tree Orbits Under Permutation Group Action

This paper uses combinatorics and group theory to answer questions about the assembly of icosahedral viral shells. Although the geometric structure of the capsid (shell) is fairly well understood in terms of its constituent subunits, the assembly process is not. For the purpose of this paper, the capsid is modeled by a polyhedron whose facets represent the monomers. The assembly process is modeled by a rooted tree, the leaves representing the facets of the polyhedron, the root representing the assembled polyhedron, and the internal vertices representing intermediate stages of assembly (subsets of facets). Besides its virological motivation, the enumeration of orbits of trees under the action of a finite group is of independent mathematical interest. If G is a finite group acting on a finite set X, then there is a natural induced action of G on the set \(\mathcal{T}_{X}\) of trees whose leaves are bijectively labeled by the elements of X. If G acts simply on X, then |X|:=|X _n |=n?|G|, where n is the number of G-orbits in X. The basic combinatorial results in this paper are (1) a formula for the number of orbits of each size in the action of G on \(\mathcal{T}_{X_{n}}\), for every n, and (2) a simple algorithm to find the stabilizer of a tree \(\tau\in\mathcal{T} _{X}\) in G that runs in linear time and does not need memory in addition to its input tree. These results help to clarify the effect of symmetry on the probability and number of assembly pathways for icosahedral viral capsids, and more generally for any finite, symmetric macromolecular assembly.     

Check of Gene Number during the Process of rDNA Magnification

THE multiple sequences of rDNA (DNA complementary to ribosomal RNA) of the Drosophila genome are localized at the bobbed locus, located in the X chromosome, position 66 and in the short arm of the Y chromosome^1,2. Wild bobbed (bb⁺) is that locus which, without a partner, gives rise to a normal phenotype. That locus which in similar conditions is incapable of giving rise to a normal phenotype is called a bobbed mutation (bb) and contains fewer genes for rRNA. The number of genes for rRNA in different individuals can vary considerably. One mechanism for rDNA variation is unequal crossing over³. Another mechanism, described by Tartof⁴, becomes apparent when individual flies, carrying only one bobbed locus, are constructed and only if such a locus is on the X chromosome; that is, if one constructs Xbb⁺/O males (and also Xbb/O males) or Xbb⁺/X_NO- females. Such individuals show a higher rDNA content than expected from the analysis of the same locus in Xbb⁺/Xbb⁺ females or in Xbb⁺/Ybb⁺ males. The increase of rDNA in this case is not inheritable⁴.     

Study of the oxidation of alkanes in their mixtures with oxygen and air under the action of a pulsed volume nanosecond discharge

The slow oxidation of alkanes (from methane to hexane) in their stoichiometric mixtures with oxygen or air under the action of nanosecond pulsed discharges was investigated. The discharges were excited in a tube of diameter 5 cm and length of 20 cm by 25-ns voltage pulses with an amplitude of 10 kV and a repetition rate of 40 Hz. The initial pressure in the mixture was varied in the range 0.76–10.1 torr. The current, the electric field strength, and the power deposited in a discharge were measured with a nanosecond time resolution. In time-resolved and time-integrated measurements, the intensities of the following bands were determined: CO ₂ ⁺ (B²Σ → X²Π, δv=0), CH(A²Δ, v′=0 → X²Π, v″=0), OH(A²Σ, v′=0 → X²Π, v″=0), CO(B¹Σ, v′=0 → A¹Π, v″=2), NO(A²Σ → X²Π, δv=3), N₂(C³Π, v′=1 → B³Π, v″=7), N₂(B³Π, v′=6 → A³Σ, v″=3), and N ₂ ⁺ (B²Σ, v′=0 → X²Σ, v″=2). The methane concentration was measured from the absorption of He-Ne laser radiation. Based on the results of optical measurements, the times of the complete oxidation of hydrocarbons were determined.     

Comprehensive dataset of mangrove tree weights in Southeast Asia

We assembled a dataset tabulating the weights of Thai and Indonesian mangrove trees that we measured between 1982 and 2001. We selected four Thai study sites in Phang Nga, Ranong, Satun, and Trat Provinces and one site in eastern Indonesia on Halmahera Island in Maluku Province. The stands in Ranong Province and on Halmahera Island were in primary forests with data collected in the 1980s and the remaining stands were in secondary forests with data collected later. We collected 124 tree samples from ten species (Avicennia alba, Bruguiera cylindrica, B. gymnorrhiza, Ceriops tagal, Rhizophora apiculata, R. mucronata, Sonneratia alba, S. caseolaris, Xylocarpus granatum, and X. moluccensis) and measured the root weights of 32 individuals of nine species (A. alba, B. cylindrica, B. gymnorrhiza, C. tagal, R. apiculata, R. mucronata, S. alba, S. caseolaris, and X. granatum). All sampled trees were subjected to a standardized protocol to obtain aboveground weights. The trunks were divided into horizontal segments from which the leaves and branches were collected separately. Roots were collected by winching them out of the ground, by trench digging, or by complete excavation. Thus, we were able to compile the weights of the trunk, branches, leaves, and roots of each tree sampled. Aerial roots were included in root weight measurements, although they were collected above ground. We compiled separate lists of trunk diameters, trunk heights, heights of the lowest living branches, and the heights of aerial roots on the trunks of trees in different size categories. Our dataset includes a wide range of tree sizes (maximum trunk diameter 48.9 cm), geographical locations (1°10′N–12°24′N, 98°32′E–123°49′E) and organ weights (trunks, branches, leaves, and roots), and therefore should prove useful in future biomass studies of mangrove forests.     

Size matters: predation of fish eggs and larvae by native and invasive amphipods

Invasive predators can have dramatic impacts on invaded communities. Extreme declines in macroinvertebrate populations often follow killer shrimp (Dikerogammarus villosus) invasions. There are concerns over similar impacts on fish through predation of eggs and larvae, but these remain poorly quantified. We compare the predatory impact of invasive and native amphipods (D. villosus and Gammarus pulex) on fish eggs and larvae (ghost carp Cyprinus carpio and brown trout Salmo trutta) in the laboratory. We use size-matched amphipods, as well as larger D. villosus reflecting natural sizes. We quantify functional responses, and electivity amongst eggs or larvae and alternative food items (invertebrate, plant and decaying leaf). D. villosus, especially large individuals, were more likely than G. pulex to kill trout larvae. However, the magnitude of predation was low (seldom more than one larva killed over 48 h). Trout eggs were very rarely killed. In contrast, carp eggs and larvae were readily killed and consumed by all amphipod groups. Large D. villosus had maximum feeding rates 1.6–2.0 times higher than the smaller amphipods, whose functional responses did not differ. In electivity experiments with carp eggs, large D. villosus consumed the most eggs and the most food in total. However, in experiments with larvae, consumption did not differ between amphipod groups. Overall, our data suggest D. villosus will have a greater predatory impact on fish populations than G. pulex, primarily due to its larger size. Higher invader abundance could amplify this difference. The additional predatory pressure could reduce recruitment into fish populations.     

Does rotan <Emphasis Type="Italic">Perccottus glenii</Emphasis> (Perciformes: Odontobutidae) eat the eggs of fish and amphibians?

The introduced fish rotan Perccottus glenii negatively affects the native ecosystems. An integrated study was performed to verify the suggestion that P. glenii feeds on eggs of fish (Rutilus rutilus, Abramis brama, Perca fluviatilis) and amphibians (Rana temporaria, R. arvalis, Bufo bufo). It was found that, during the intraoral testing of fish eggs, P. glenii perceives it as an edible item and swallows; however, under experimental conditions, this predator is limited in its ability for finding this prey because of its immobility. At the last stages of development, the movements of embryos within eggs attract the attention of P. glenii. This increases the vulnerability of fish eggs. In a large water body, there may be a spatial biotopic separation of the sites of egg deposition of some fish (for instance, perch) and the sites of concentrations of P. glenii. This makes eggs inaccessible for this predator. The amphibian eggs, on the contrary, are rejected by P. glenii after intraoral testing, which is determined by the presence of a thick jelly coat. During the period of development of eggs of frogs and toad in a pond, P. glenii actively feed (diverse invertebrates and adult newts were found in their diet); however, they ignore amphibian eggs that successfully develop in water bodies inhabited by P. glenii.     

Nutritional symbionts of a putative vector, <Emphasis Type="Italic">Xyleborus bispinatus</Emphasis>, of the laurel wilt pathogen of avocado, <Emphasis Type="Italic">Raffaelea lauricola</Emphasis>

Ambrosia beetles subsist on fungal symbionts that they carry to, and cultivate in, their natal galleries. These symbionts are usually saprobes, but some are phytopathogens. Very few ambrosial symbioses have been studied closely, and little is known about roles that phytopathogenic symbionts play in the life cycles of these beetles. One of the latter symbionts, Raffaelea lauricola, causes laurel wilt of avocado, Persea americana, but its original ambrosia beetle partner, Xyleborus glabratus, plays an uncertain role in this pathosystem. We examined the response of a putative, alternative vector of R. lauricola, Xyleborus bispinatus, to artificial diets of R. lauricola and other ambrosia fungi. Newly eclosed, unfertilized females of X. bispinatus were reared in no-choice assays on one of five different symbionts or no symbiont. Xyleborus bispinatus developed successfully on R. lauricola, R. arxii, R. subalba and R. subfusca, all of which had been previously recovered from field-collected females of X. bispinatus. However, no development was observed in the absence of a symbiont or on another symbiont, Ambrosiella roeperi, recovered from another ambrosia beetle, Xylosandrus crassiusculus. In the no-choice assays, mycangia of foundress females of X. bispinatus harbored significant colony-forming units of, and natal galleries that they produced were colonized with, the respective Raffaelea symbionts; with each of these fungi, reproduction, fecundity and survival of the beetle were positively impacted. However, no fungus was recovered from, and reproduction did not occur on, the A. roeperi and no symbiont diets. These results highlight the flexible nature of the ambrosial symbiosis, which for X. bispinatus includes a fungus with which it has no evolutionary history. Although the “primary” symbiont of the neotropical X. bispinatus is unclear, it is not the Asian R. lauricola.     

Présence dans une population congolaise deMus (Leggada) triton Th. de femelles hétérozygotes pour une délétion caractérisée par la suppression du bras court de l'un des chromosomes X métacentriques

A sample of 12Mus (Leggada) triton Th. from the region of Bukavu (Democratic Republic of Congo) contains 5 ♂♂ and 7 ♀♀. 2N=32. All the autosomes are acrocentric. The sex-chromosomes of the ♂ are of the typeX—Y, theX beeing a big submetacentric (I.C.=0,4). Three ♀♀ possess two metacentricX, as expected. By four ♀♀, there is only one typicalX whose partner is acrocentric and as long as the long arm of a normalX. ThisX must have been arisen through the deletion of the short arm and is calledX _ddc. The statistical analysis of the sample is compatible with this pattern:

$$\begin{array}{*{20}c} { \circ \circ } \\ { + + } \\ \end{array} \begin{array}{*{20}c} {X---X = 4/9} \\ {X---X_{dc} = 4/9} \\ {X_{dc} ---X_{dc} = 1/9} \\ \end{array} \begin{array}{*{20}c} { \nearrow \nearrow } \\ { \circ \circ } \\ \end{array} \begin{array}{*{20}c} {X---Y = 2/3} \\ {X_{dc} ---Y = 1/3} \\ \end{array} $$     

A novel NADPH-dependent reductase of <Emphasis Type="Italic">Sulfobacillus acidophilus</Emphasis> TPY phenol hydroxylase: expression,characterization, and functional analysis

The reductase component (MhpP) of the Sulfobacillus acidophilus TPY multicomponent phenol hydroxylase exhibits only 40 % similarity to Pseudomonas sp. strain CF600 phenol hydroxylase reductase. Amino acid sequence alignment analysis revealed that four cysteine residues (Cys-X ₄ -Cys-X ₂ -Cys-X _29-35 -Cys) are conserved in the N terminus of MhpP for [2Fe-2S] cluster binding, and two other motifs (RXYS and GXXS/T) are conserved in the C terminus for binding the isoalloxazine and phosphate groups of flavin adenine dinucleotide (FAD). Two motifs (S/T-R and yXCGp) responsible for binding to reduce nicotinamide adenine dinucleotide phosphate (NADPH) are also conserved in MhpP, although some residues differ. To confirm the function of this reductase, MhpP was heterologously expressed in Escherichia coli BL21(DE3) and purified. UV-visible spectroscopy and electron paramagnetic resonance spectroscopy revealed that MhpP contains a [2Fe-2S] cluster. MhpP mutants in which the four cysteine residues were substituted via site-directed mutagenesis lost the ability to bind the [2Fe-2S] cluster, resulting in a decrease in enzyme-specific oxidation of NADPH. Thin-layer chromatography revealed that MhpP contains FAD. Substrate specificity analyses confirmed that MhpP uses NADPH rather than NADH as an electron donor. MhpP oxidizes NADPH using cytochrome c, potassium ferricyanide, or nitro blue tetrazolium as an electron acceptor, with a specific activity of 1.7 ± 0.36, 0.78 ± 0.13, and 0.16 ± 0.06 U/mg, respectively. Thus, S. acidophilus TPY MhpP is a novel NADPH-dependent reductase component of phenol hydroxylase that utilizes FAD and a [2Fe-2S] cluster as cofactors.