74 research outputs found
Last-male sperm precedence in Rhynchophorus ferrugineus (Olivier): observations in laboratory mating experiments with irradiated males
The Red PalmWeevil (RPW)Rhynchophorus ferrugineus(Olivier 1790) is an invasive
pest from southeastern Asia and Melanesia that in the last 30 years has spread widely
in the Middle East and Mediterranean Basin. Its stem-boring larvae cause great damage to several palm species of the Arecaceae family, many of which are economically
important for agricultural and ornamental purposes. Therefore, great attention has recently been focused in studying this species to identify sustainable and effective eradication strategies, such as sterile insect technique (SIT). The rapid spread of RPW is
associated with its high reproductive success. To evaluate the suitability of a SIT strategy, particular physiological and behavioral aspects of RPW reproduction, such as the
presence of polyandry and post-copulatory sperm selection mechanisms, were
investigated. To determine paternity of progeny from multiply mated females, double-crossing experiments were carried out confining individual females with either a
wild-type male or a γ-irradiated male (Co-60). Fecundity and fertility of females were
scored to evaluate post-copulatory sperm selection. Results showed that progeny
were almost exclusively produced by the sperm of the second male, suggesting that
a last-male sperm precedence is expressed at high levels in this species, and providing
interesting insights for an area-wide RPW management strategy such as the SIT
Synergistic Hypergolic Ignition of Amino End Group in Monomers and Polymers
A few monomers, oligomers and polymers with amino end groups have been discovered to undergo synergistic ignition with red fuming nitric acid (RFNA) when mixed with large quantities of magnesium powder. Aluminium powder under similar conditions does not ignite the mixture while powders of Zn, Co and Cu cause the ignition. Amongst the polymers used in the experiment commercially available nylon 6 is the most important which may be used as a binder for rocket propellant fuel grains, hypergolic with RFNA. Degree of polymerisation or the chain length of the polymers does not drastically affect the synergistic ignition of the polymer mixture with magnesium powder but high molecular weight and fully aromatised polymers like Kevlar and Nomex fail to ignite under similar conditions. Based upon the earlier work of the authors, explanations for the phenomena oberved have been provided in terms of creation of hot spots leading to ignition at the amino end groups
Severe Hypertriglyceridemia due to a novel p.Q240H mutation in the Lipoprotein Lipase gene
Application of Colloid Probe Atomic Force Microscopy to the Adhesion of Thin Films of Viscous and Viscoelastic Silicone Fluids
Originalarbeiten: Human Serum Albumin Microspheres for Lung Imaging – Preparation and Evaluation
Ab initio investigation of benzene clusters: Molecular Tailoring Approach
An exhaustive study on the clusters of benzene (Bz)<SUB>n</SUB>, n = 2-8, at MP2/6-31++G level of theory is reported. The relative strengths of CH-π and π -π interactions in these aggregates are examined, which eventually govern the pattern of cluster formation. A linear scaling method, viz., molecular tailoring approach (MTA), is efficiently employed for studying the energetics and growth patterns of benzene clusters consisting up to eight benzene (Bz) units. Accuracy of MTA-based calculations is appraised by performing the corresponding standard calculations wherever possible, i.e., up to tetramers. For benzene tetramers, the error introduced in energy is of the order of 0.1 mH ( ~ 0.06 kcal/mol). Although for higher clusters the error may build up, further corrections based on many-body interaction energy analysis substantially reduce the error in the MTA-estimate. This is demonstrated for a prototypical case of benzene hexamer. A systematic way of building up a cluster of n monomers (n-mer) which employs molecular electrostatic potential of an (n-1)-mer is illustrated. The trends obtained using MTA method are essentially identical to those of the standard methods in terms of structure and energy. In summary, this study clearly brings out the possibility of effecting such large calculations, which are not possible conventionally, by the use of MTA without a significant loss of accuracy
Predi-XY: a python program for automated generation of NICS-XY-scans based on an additivity scheme
Theory and Calculations of Molecules Containing Heavier Main Group Elements and Fullerenes Encaging Transition Metals: Interplay with Experiment
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