A numerical model of seasonal foraging characteristics of successful underground colonies of Vespula vulgaris (Hymenoptera,Vespidae) in England

Summary. A numerical model has been developed to calculate the total number of transits in each worker foraging category for the 170 days of development of a successful colony. Seven categories of workers are considered: two of outgoers (earth carriers and non-earth outgoers), and five of incomers (pulp, flesh, full fluid, and partial fluid carriers, and empty incomers). The model allows for variation in the length of the foraging day and for hypothetical smaller and larger colonies. Estimates of each category are given for the queen, smaller and larger worker colony. Estimates of 1.3–4.5 million, for smaller and larger colonies, each of incomer and outgoer transits are calculated from the model. The slight excess of outgoer over incomer transits could be accounted for, in part, by the mortality of workers away from the nest. Percentages of each worker category are given for the pre-exponential small-cell, exponential small-cell and large-cell colonies. It is hypothesized that there is a balance between fluid and solid transits for efficient brood rearing. There may be restraints in the social wasp system that restrict brood rearing. Estimates which are independent of the foraging model are calculated for the number of loads to create the nest cavity and build the pulp nest which broadly agree with the model outputs.Received 15 July 2004; revised 15 December 2004; accepted 23 December 2004.     

Enhanced algal growth rate in a Taylor vortex reactor

The rate of production of algal biomass in optically dense photobioreactors depends crucially on the temporal light exposure of microorganisms, which in turn is determined by fluid flow patterns and the quantity and spatial distribution of photosynthetically active radiation. In this report it is demonstrated that highly organized and robust toroidal flow structures known as Taylor vortices cause significant increases in the rate of biomass production, efficiency of light utilization, and CO₂ uptake, and these effects become more pronounced at higher Reynolds numbers. In light of these findings and previously reported experiments using Taylor vortex flow to culture algae, it is argued that the flashing light effect, rather than mass transport effects, is responsible for the observed increases in the rate of photosynthesis. Biotechnol. Bioeng. 2013; 110: 2140–2149. © 2013 Wiley Periodicals, Inc.     

Interaction between Meloidogyne incognita and Pochonia chlamydosporia and their effects on the growth of Phaseolus vulgaris

An experiment was conducted to test the effect of different doses of 2, 4 and 8?g/2?kg of soil of Pochonia chlamydosporia against the root-knot nematode (Meloidogyne incognita) on Phaseolus vulgaris. It was observed that inoculation of plant with the nematode alone, and 15?days prior to fungal inoculation, reduced the plant growth when compared with the plant with fungal application followed by the nematode. Plant length, fresh and dry weight, chlorophyll, carotenoid, protein contents and nitrate reductase activity decreased in nematode-infested plants. Application of higher dose of 8?g/2?kg of soil of P. chlamydosporia increased all the plant growth parameters as well as biochemical parameters. Highest number of galls per root system was recorded on the plants infested with nematode but not treated with the fungus. However, application of fungus prior to nematode inoculation improved the plant growth and reduced the number of galls and the number of egg masses per root system.     

Einfluß der Unterbrechung langjähriger Getreide-Fruchtfolgen durch zweijährigen Luzerne-Anbau auf den Kornertrag sowie auf den Befall des Winterweizens durch Pseudocercosporella herpotrichoides (Fron) Deighton

Die herbizide Wirksamkeit von Bromoxynil und Phenmedipham wird in starkem Maße von der Lösungsmittelkomponente der Herbizidformulierung beeinflußt. Es zeigt sich, daß die Photosynthesehemmung — als Maß für die Herbizidwirkung — mit zunehmender Hydrophilie der verwendeten Lösungsmittel sinkt, was insbesondere anhand der untersuchten Essigsäurealkylesterreihe nachweisbar ist. Zwischen der Wirkstoffapplikation auf Ganzblättern und isolierten Chloroplasten treten beträchtliche Wirkungsunterschiede auf. Demnach ist der wirkungsbegrenzende Schritt nicht innerhalb der Thylakoidmembran selbst zu suchen sondern findet auf dem Wege von der Blattoberfläche zum Chloroplasten statt.     

Variation in the quality of Vespula vulgaris (L.) queens (Hymenoptera: Vespidae) and its significance in wasp population dynamics

Abstract

Density‐related variation in queen quality has been proposed as a possible mechanism regulating population fluctuations in Vespula species. We investigated annual variation in the quality (size, weight, and fat content) of adult V. vulgaris queens representing four stages of their life cycle (spring, founding, developing, and emerged) taken from six sites in beech forest, South Island, New Zealand. For each queen the dry weight, head width, and thorax length was measured. For a subsample of queens, the fat content was determined by ether extraction. The size of queen cells was measured from a subsample of nests. Size, weight, and fat content of queens varied between wasp colonies and sites. The smallest juvenile queens were under‐represented in the reproductive population. There was no direct link between body size and food supply. Size and weight of developing queens increased as the number of cells in the nest increased. The size of the queen cells varied significantly among layers in a nest and among nests. The under‐representation of small queens in the reproductive population suggests that queen quality may affect survival and/or competitive ability by increasing winter fat storage, nest building activity, and/or success in usurpation disputes.     

Two new species of the genus Rhyacophila Pictet (Trichoptera: Rhyacophilidae) from India

Two new species of the genus Rhyacophila Pictet from the Indian Himalayas, i.e. Rhyacophila himalayensis n. sp. from Badrinath (Uttarakhand) of the R. divaricata branch and Rhyacophila indica n. sp. from Gangtok (Sikkim) of the R. vulgaris branch are described and illustrated.     

Intersubnuclear Connections within the Rat Trigeminal Brainstem Complex

Prior intracellular recording and labeling experiments have documented local-circuit and projection neurons in the spinal trigeminal (V) nucleus with axons that arborize in more rostral and caudal spinal trigeminal subnuclei and nucleus principalis. Anterograde tracing studies were therefore carried out to assess the origin, extent, distribution, and morphology of such intersubnuclear axons in the rat trigeminal brainstem nuclear complex (TBNC). Phaseolus vulgaris leucoagglutinin (PHA-L) was used as the anterograde marker because of its high sensitivity and the morphological detail provided. Injections restricted to TBNC subnucleus caudalis resulted in dense terminal labeling in each of the more rostral ipsilateral subnuclei. Subnucleus interpolaris projected ipsilaterally and heavily to magnocellular portions of subnucleus caudalis, as well as subnucleus oralis and nucleus principalis. Nucleus principalis, on the other hand, had only a sparse projection to each of the caudal ipsilateral subnuclei. Intersubnuclear axons most frequently traveled in the deep bundles within the TBNC, the V spinal tract, and the reticular formation. They gave rise to a number of circumscribed, highly branched arbors with many boutons of the terminal and en passant types.

Retrograde single- or multiple-labeling experiments assessed the cells giving rise to TBNC intersubnuclear collaterals. Horseradish peroxidase (HRP) and/or fluorescent tracer injections into the thalamus, colliculus, cerebellum, nucleus principalis, and/or subnucleus caudalis revealed large numbers of neurons in subnuclei caudalis, interpolaris, and oralis projecting to the region of nucleus principalis. Cells projecting to more caudal spinal trigeminal regions were most numerous in subnuclei interpolaris and oralis. Some cells in lamina V of subnucleus caudalis and in subnuclei interpolaris and oralis projected to thalamus and/or colliculus, as well as other TBNC subnuclei. Such collateral projections were rare in nucleus principalis and more superficial laminae of subnucleus caudalis. TBNC cells labeled by cerebellar injections were not double-labeled by tracer injections into the thalamus, colliculus, or TBNC.

These findings lend generality to currently available data obtained with intracellular recording and HRP labeling methods, and suggest that most intersubnuclear axons originate in TBNC local-circuit neurons, though some originate in cells that project to midbrain and/or diencephalon.     

Occurrence of l-(−)-Pipecolic Acid in the Culture Medium of Rumen Ciliate Protozoa

Effect of phenoxazine derivatives (actinomycin D, l,8-dimethyl-3-aminophenoxazone-2, 3-aminophenoxazone-2, sodium resazurate, gallocyanine, fluorescent blue and capri blue) on amino acid transport in rat small intestine was investigated using tissue accumulation method. Capri blue (CI–51015) inhibited the accumulation of l-leucine, l-alanine and l-valine, and scarcely inhibited that of D-glucose. Kinetic analysis showed that the inhibition of amino acid accumulation by this pigment was non-competitive. Actinomycin D had no effect on amino acids and d-glucose accumulation in vitro at the high and low concentrations of these substances. High concentration of actinomycin D and long period of incubation had no effect, too. Accumulation of amino acids into the intestinal tissue was not significantly decreased or increased by the presence of other phenoxazine derivatives.