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

Current Regulatory Requirements for Biosimilars in Six Member Countries of BRICS-TM: Challenges and Opportunities

© 2021 Rahalkar, Sheppard, Santos, Dasgupta, Perez-Tapia, Lopez-Morales and Salek. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/Background: The aim of the study was to identify, interpret, and compare the current perspectives of regulatory agencies in six member countries of BRICS-TM (Brazil, Russia, India, China, South Africa, Turkey, and Mexico) on the different criteria used for biosimilar development and marketing authorisation process. Methods: A semi-quantitative questionnaire was developed covering the organisation of agency, biosimilar development criteria and marketing authorisation process and sent to seven regulatory agencies covering the BRICS-TM countries. All data was kept anonymous and confidential. Data processing and analysis was carried out; descriptive statistics were used for quantitative data and content analysis was employed to generate themes for qualitative data. Results: Out of the seven regulatory agencies included in the study, six representatives provided the responses. The perspectives of these six regulatory agencies varied on a number of aspects relating to the review criteria for biosimilar development and licencing process. The most prevalent model for data assessment is the “full review” of a marketing authorisation application. There is lack of a standard approach across the agencies on sourcing of the reference biological product, in vivo toxicity studies and confirmatory clinical studies. Most agencies restrict interaction with biosimilar developers and any scientific advice is non-binding. The marketing authorisation approval depends on scientific assessment of the dossier, sample analysis and GMP certification. The agencies do not issue any public assessment report specifying the summary basis of biosimilar approval. Conclusion: Regulatory agencies across the six emerging economies are steadily improving the regulatory mechanism in the area of biosimilars. However, there remains scope for increasing the effectiveness and efficiency of the processes by encouraging open and transparent interaction with developers, adopting a flexible approach toward accepting advanced analytical data in lieu of clinical studies and enhancing regulatory reliance amongst agencies. This will help to simplify the new biosimilar development programmes and make them more cost-effective.Peer reviewe

The 'K' selected oligophilic bacteria: a key to uncultured diversity?

Molecular techniques have made it increasingly clear that a large proportion of bacterial diversity in natural habitats is uncultured and therefore unexplored. We suggest and give evidence in support of a hypothesis that a large proportion, if not all, of the uncultured diversity from a variety of aquatic and terrestrial habitats are oligophilic (oligotrophic) bacteria. Oligophilic bacteria grow only on dilute nutrient media and form small or microscopic colonies. A technique to cultivate and isolate the moderately oligophilic bacteria was developed and 90 cultures isolated, The twelve bacterial cultures characterized showed high growth yield coefficients and carbon conversion efficiencies at low substrate concentrations and progressively decreased with increasing substrate concentrations. Most of the growth yields were substantially higher than those reported in the literature and lie near the theoretical maximum. Slow growth rates and high yields indicate that they are 'K' selected species. 16S rDNA partial sequence analysis of the isolates indicates that it is a novel as well as diverse group

Images - Extra (too many) carpal bones in Larsen's syndrome

Multiple carpal bones may be seen in different syndromes, especially Larsen's syndrome. A case of Larsen's syndrome with many typical features and “too many” carpal bones, is described