Environmental Pursuits In Nanomaterial Systems Science With Indian Exemplars

The behavior and pattern of NPs of minerals in the evolutionary history of the earth vis – a –vis the environmental context are inquired into, with a riverine system as a model. The study of fractal dimensions of NPs of interest serves as an aid to obtain a comprehensive view of natural NPs in the model system. The present study combines inputs from work done on nanoparticles, derived from the Subanarekha River System and products of base metal mine effluents that are rich in NPs of minerals. The authors believe this study would help to establish certain universalities about NPs and provide an updated framework for understanding the current state of nanomineral science

Visualization of ribosomal RNA operon copy number distribution

<p>Abstract</p> <p>Background</p> <p>Results of microbial ecology studies using 16S rRNA sequence information can be deceiving due to differences in rRNA operon copy number and genome size of the detected organisms. It therefore will be useful for investigators to have a better understanding of how these two parameters differ in various organism types. In this study, the number of ribosomal operons and genome size were separately mapped onto a Bacterial phylogenetic tree.</p> <p>Results</p> <p>A representative Bacterial tree was constructed using 31 marker genes found in 578 bacterial genome sequences. Organism names are displayed on the trees using graduations of color such that similar colors indicate similar numbers of operons or genome size. The resulting images provide an intuitive understanding of how copy number and genome size vary in different Bacterial phyla.</p> <p>Conclusion</p> <p>Once the phylogenetic position of a novel organism is known the number of rRNA operons, and to a lesser extent the genome size, can be estimated by examination of the colored maps. Further detail can then be obtained for members of relevant taxa from the rrnDB database.</p

Differential Occurrence of Cuticular Wax and Its Role in Leaf Physiological Mechanisms of Three Edible Aroids of Northeast India

The localization of cuticular wax (CW) on the leaf epidermis and its interaction with the physiological mechanisms of three edible aroids, Alocasia, Colocasia, and Xanthosoma, were assessed. CW in the leaf tissues was visualized using scanning electron microscopy, which was higher in Colocasia (10.61 mg·dm−2) and Xanthosoma (11.36 mg·dm−2) than in Alocasia (1.36 mg·dm−2). Colocasia CW exhibited superhydrophobic properties with a higher static contact angle (CA) (>150◦) than Xanthosoma (99.0◦) and Alocasia (128.7◦). The higher CW in Colocasia and Xanthosoma resulted in better leaf chlorophyll stability, moisture retention ability, and cellular membrane integrity compared to Alocasia. CW acted as a protecting barrier against deleterious solar radiation in terms of sun protection factor (SPF). The glossy appearance of wax crystals in the Alocasia leaf cuticles resulted in higher SPF. Overall, Colocasia CW highly influenced the qualitative and protective mechanisms of the leaf. Our study sheds light on the pivotal role of CW in the physiological properties of aroid leaves, which would be useful for the selection of wax-rich plants for augmenting future breeding strategies. The information would also be useful for further exploration of the industrial potential of superhydrophobic wax crystals obtained from edible aroids.Fil: Pieniazek, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. ICAR Research Complex for North Eastern Hill Region; IndiaFil: Dasgupta, Madhumita. ICAR Research Complex for North Eastern Hill Region; IndiaFil: Messina, Valeria Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Devi, Mayengbam Premi. ICAR Research Complex for North Eastern Hill Region; IndiaFil: Devi, Yumnam Indrani. ICAR Research Complex for North Eastern Hill Region; IndiaFil: Mohanty, Sansuta. ICAR-Indian Institute of Horticultural Research; IndiaFil: Singh, Satyapriya. ICAR-Indian Institute of Horticultural Research; IndiaFil: Sahoo, Bibhuti Bhusan. Odisha University of Agriculture and Technology; IndiaFil: Nongdam, Potshangbam. Manipur University; IndiaFil: Acharya, Gobinda Chandra. ICAR-Indian Institute of Horticultural Research; IndiaFil: Sahoo, Manas Ranjan. ICAR-Indian Institute of Horticultural Research; India. ICAR Research Complex for North Eastern Hill Region; Indi

Non Inflammatory Boronate Based Glucose-Responsive Insulin Delivery Systems

Boronic acids, known to bind diols, were screened to identify non-inflammatory cross-linkers for the preparation of glucose sensitive and insulin releasing agglomerates of liposomes (Agglomerated Vesicle Technology-AVT). This was done in order to select a suitable replacement for the previously used cross-linker, ConcanavalinA (ConA), a lectin known to have both toxic and inflammatory effects in vivo. Lead-compounds were selected from screens that involved testing for inflammatory potential, cytotoxicity and glucose-binding. These were then conjugated to insulin-encapsulating nanoparticles and agglomerated via sugar-boronate ester linkages to form AVTs. In vitro, the particles demonstrated triggered release of insulin upon exposure to physiologically relevant concentrations of glucose (10 mmoles/L–40 mmoles/L). The agglomerates were also shown to be responsive to multiple spikes in glucose levels over several hours, releasing insulin at a rate defined by the concentration of the glucose trigger

Positive feedback and noise activate the stringent response regulator Rel in mycobacteria

Phenotypic heterogeneity in an isogenic, microbial population enables a subset of the population to persist under stress. In mycobacteria, stresses like nutrient and oxygen deprivation activate the stress response pathway involving the two-component system MprAB and the sigma factor, SigE. SigE in turn activates the expression of the stringent response regulator, rel. The enzyme polyphosphate kinase 1 (PPK1) regulates this pathway by synthesizing polyphosphate required for the activation of MprB. The precise manner in which only a subpopulation of bacterial cells develops persistence, remains unknown. Rel is required for mycobacterial persistence. Here we show that the distribution of rel expression levels in a growing population of mycobacteria is bimodal with two distinct peaks corresponding to low (L) and high (H) expression states, and further establish that a positive feedback loop involving the mprAB operon along with stochastic gene expression are responsible for the phenotypic heterogeneity. Combining single cell analysis by flow cytometry with theoretical modeling, we observe that during growth, noise-driven transitions take a subpopulation of cells from the L to the H state within a "window of opportunity" in time preceding the stationary phase. We find evidence of hysteresis in the expression of rel in response to changing concentrations of PPK1. Our results provide, for the first time, evidence that bistability and stochastic gene expression could be important for the development of "heterogeneity with an advantage" in mycobacteria.Comment: Accepted for publication in PLoS On

Many nonuniversal archaeal ribosomal proteins are found in conserved gene clusters

The genomic associations of the archaeal ribosomal proteins, (r-proteins), were examined in detail. The archaeal versions of the universal r-protein genes are typically in clusters similar or identical and to those found in bacteria. Of the 35 nonuniversal archaeal r-protein genes examined, the gene encoding L18e was found to be associated with the conserved L13 cluster, whereas the genes for S4e, L32e and L19e were found in the archaeal version of the spc operon. Eleven nonuniversal protein genes were not associated with any common genomic context. Of the remaining 19 protein genes, 17 were convincingly assigned to one of 10 previously unrecognized gene clusters. Examination of the gene content of these clusters revealed multiple associations with genes involved in the initiation of protein synthesis, transcription or other cellular processes. The lack of such associations in the universal clusters suggests that initially the ribosome evolved largely independently of other processes. More recently it likely has evolved in concert with other cellular systems. It was also verified that a second copy of the gene encoding L7ae found in some bacteria is actually a homolog of the gene encoding L30e and should be annotated as such