Neurosecretory cells in Diptera

The neurosecretory cells were studied in 20 dipteran species belonging to three suborders. The NSC are localized in (a) the frontal ganglion (in 10 of the 20 species studied), (b) the pars intercerebralis region of the protocerebrum (in the median and lateral groups), (c) the tritocerebral region of the brain (in 8 of the 20 species studied) and (d) the suboesophageal ganglion. In one species, NSC were also seen in the prothoracic ganglion. The NSC were classified as types A, B and C/D. The NSC of the median group of the pars intercerebralis were unusually large compared with the size of the brain. The number, size and distribution of the cells are discussed.     

Antifungals,arthropods and antifungal resistance prevention: lessons from ecological interactions

Arthropods can produce a wide range of antifungal compounds, including specialist proteins, cuticular products, venoms and haemolymphs. In spite of this, many arthropod taxa, particularly eusocial insects, make use of additional antifungal compounds derived from their mutualistic association with microbes. Because multiple taxa have evolved such mutualisms, it must be assumed that, under certain ecological circumstances, natural selection has favoured them over those relying upon endogenous antifungal compound production. Further, such associations have been shown to persist versus specific pathogenic fungal antagonists for more than 50 million years, suggesting that compounds employed have retained efficacy in spite of the pathogens'' capacity to develop resistance. We provide a brief overview of antifungal compounds in the arthropods’ armoury, proposing a conceptual model to suggest why their use remains so successful. Fundamental concepts embedded within such a model may suggest strategies by which to reduce the rise of antifungal resistance within the clinical milieu.     

LIBS: A Quality Control Tool for Food Supplements

In the present paper the ability of calibration free laser induced breakdown spectroscopy (CF-LIBS) as a quality control tool to monitor the composition of different minerals present in food supplement samples belonging to Indian brands (brand-A and brand-B) has been demonstrated. LIBS spectra of these two food supplements (brand-A and brand-B) available in the form of tablet have been recorded. As reported by manufacturers of these two food supplements, LIBS spectra of brand-A contains the spectral signatures of minerals like Ca, Mg, C, P, Zn, Fe, Cu, and Cr whereas LIBS spectra of brand-B shows the presence of spectral lines like Ca, Mg and C. The spectral signatures of Na and K are also found in both brands whereas spectral signature of Ti is observed only in brand-B but these elements are not mentioned on the nutritional label of the brands. The quantitative analysis of mineral contents in food supplements has been done using CF-LIBS for brand A and brand B to verify the content of the minerals reported by the manufacturer of the food supplements. Our results show that Ca and Mg are the main matrix elements of these brands. The concentration of minor and trace elements estimated using CF-LIBS technique is found in agreement with the reported nutritional values of both the brands. The concentration of major elements Ca and Mg are also estimated from Atomic Absorption Spectroscopy which is in close agreement with CF-LIBS result.     

Crystal structure of apo and copper bound HP0894 toxin from Helicobacter pylori 26695 and insight into mRNase activity

The toxin–antitoxin (TA) systems widely spread among bacteria and archaea are important for antibiotic resistance and microorganism virulence. The bacterial kingdom uses TA systems to adjust the global level of gene expression and translation through RNA degradation. In Helicobacter pylori, only two TA systems are known thus far. Our previous studies showed that HP0894–HP0895 acts as a TA system and that HP0894 exhibits intrinsic RNase activity. However, the precise molecular basis for interaction with substrate or antitoxin and the mechanism of mRNA cleavage remain unclear. Therefore, in an attempt to shed some light on the mechanism behind the TA system of HP0894–HP0895, here we present the crystal structures of apo- and metal-bound H. pylori 0894 at 1.28 Å and 1.89 Å, respectively. Through the combined approach of structural analysis and structural homology search, the amino acids involved in mRNase active site were monitored and the reorientations of different residues were discussed in detail. In the mRNase active site of HP0894 toxin, His84 acts as a catalytic residue and reorients itself to exhibit this type of activity, acting as a general acid in an acid–base catalysis reaction, while His47 and His60 stabilize the transition state. Lys52, Glu58, Asp64 and Arg80 have phosphate binding and specific sequence recognition. Glu58 also acts as a general base, and substrate reorientation is caused by Phe88. Based on experimental findings, a model for antitoxin binding could be suggested.     

Withania somnifera (Ashwagandha): Regeneration through Meristem Culture

High frequency of callus induction was achieved from shoot tip explants (80%) of Withania somnifera (Hindi name-Ashwagandha) as compared to leaf explants (70%), on MS medium supplemented with IAA (56μM) and Kinetin (56μM). When hormone-free MS medium was fortified with vitamins [thiamine. HCI (3μM), nicotinic acid (40.7μM) and pyridoxine. HCI (24.3μM)], it was found suitable for complete plant regeneration through meristem culture.     

Study of Surface-Enhanced Raman Scattering of Plasmonic Coupled Biomolecule: Role of Multi-Layered Nanosphere

Plasmonics - In this communication, we study the surface enhanced Raman scattering (SERS) by a molecule which is adsorbed on a trilayer (Ag@SiO2@Ag) spherical shaped metallic nanostructure. We have...