Nanoparticles influence on expression of cell cycle related genes in Drosophila: a microarray-based toxicogenomics study

Relatively little is known regarding the interaction of nanoscale objects with dynamic complex biological systems. Microarray-based toxicogenomics studies may serve as a suitable technique to explore the genome wide effects of nanoparticles on any organism through a single experiment. The influence of nanoporous aluminosilicate nanoparticles (NP), citrate-capped gold NP, lipophilic silica NP, BSA-capped silver NP, and lipophilic zinc oxide NP were studied on 75 cell cycle-related genes of adult Drosophila melanogaster. Microarray experiments were conducted after the flies were fed with NP-mixed media for 15 days. Data showed that silver, zinc oxide, and alumino silicate NP predominantly perturbed cell cycle genes, whereas gold and silica NP exerted the least influence on these genes.     

Structural alterations in compound eye of Drosophila melanogaster in response to sodium fluoride treatment

Sodium fluoride, used as a pesticide in agriculture, is also an ingredient of toothpastes which help to fight dental problems. In this study, Drosophila melanogaster, a non-target organism, is used to explore morphological changes in the adult compound eye as a function of exposure to fluoride at 20, 40, 80, 100 and 150 mg L^?1, using scanning electron microscopy. The experimental concentrations were much lower than the ones used in the studies of the British Association of Community Dentistry. Distinct morphological alterations in the eye of the treated insects revealed ommatidial ridges and disoriented mechanosensory bristles which were most prominent in the 40 and 80 mg L^?1 treatment groups. Since humans and Drosophila share homology in many genes that are involved in developmental pathways, the present findings raise concern on the use of sodium fluoride as a pesticide.     

Livestock carrying capacity evaluation in an integrated farming system: A case study from the mid-hills of Nepal

The crop livestock integrated farming system practiced in hilly regions of developing countries largely depends on the ecosystem as a whole. More especifically, the livestock component of the farming system relies heavily on natural resources such as forest, grazing and agricultural land for the supply of feed and fodder. The importance of animals as agents of nutrient recycling, sources of rural energy in terms of draft power and fuel, as well as being major contributors to the farm economy, has resulted in an increased population of ruminants in these regions, creating a threat to the sustainability and productivity of these land resources. This paper is an attempt to evaluate the livestock carrying capacity of land resources and to formulate the optimum herd size compatible with the differently resourced farm categories within the sub-watershed region of the mid-hills in Nepal. Our analysis reveals that the livestock carrying capacity of the land resources at the watershed level is 11696 Livestock Units (LU), whereas current stocking is 12985 LU, suggesting an overstocking of 1289 LU at the watershed level. Total feed supply from different sources is 12668 mt/yr whereas current Total Digestive Nutrient (TDN) demand is 14060 mt/yr, a negative balance of 1393 mt/yr. The excess livestock at the sub-watershed level directly implies excess livestock holding, producing a poor nutritional status for the farm household. Linear programming analysis reveals that the farmers of large, medium and small category farms can optimize their livestock holding by a combination of 3 LU buffaloes and 4 LU goats, 2 LU buffaloes and 4 LU goats and 1 LU buffaloes and 4.4 LU goats, thus giving maximum return to the farm family without exerting pressure on fragile natural resources.     

Investigating the complex relationship between in situ Southern Ocean pCO_{2} and its ocean physics and biogeochemical drivers using a nonparametric regression approach

The objective in this paper is to investigate the use of a non-parametric approach to model the relationship between oceanic carbon dioxide \((pCO_2)\) and a range of ocean physics and biogeochemical in situ variables in the Southern Ocean, which influence its in situ variability. The need for this stems from the need to obtain reliable estimates of carbon dioxide concentrations in the Southern Ocean which plays an important role in the global carbon flux cycle. The main challenge involved in this objective is the spatial limitation and seasonal bias of the in situ data. Moreover, studies have also reported that the relationship between \(pCO_2\) and its drivers is complex. As such, in this paper, we use the non-parametric kernel regression approach since it is able to accurately capture the complex relationships between the response and predictor variables. In this analysis we use the in situ data obtained from the SANAE49 return leg journey between Antarctic to Cape Town. To the best of our knowledge, this is the first time this data set has been subjected to such analysis. The model variants were developed on a training data subset, and the ‘goodness’ of the models were assessed on an “unseen” test data subset. Results indicate that the nonparametric approach consistently captures the relationship more accurately in terms of mean square error, root mean square error and mean absolute error, over a standard parametric approach (multiple linear regression). These results provide a platform for using the developed nonparametric regression model based on in situ measurements to predict \(pCO_2\) for a larger spatial region in the Southern Ocean based on satellite biogeochemical measurements of predictor variables, given that satellites do not measure \(pCO_2\) .     

Nanoweapon: control of mosquito breeding using carbon-dot-silver nanohybrid as a biolarvicide

Health issues induced by mosquito illnesses highlight the need for effective control. Here, we developed an efficient carbon-dot-silver nanohybrid to control Anopheles stephensi and Culex quinquefasciatus mosquito species. The nanohybrid was synthesized using a thermal method without addition of any toxic-reducing agent. Monohybrids are found within the ranges of 2–6 nm for carbon-dot and 10–35 nm for silver nanoparticles with uniform distribution. The uniformly dispersed nanohybrid solutions show excellent larvicidal activity within the concentration range of 0.5–1.0 ppm. Morphological studies evidence the presence of strong bonds between nanohybrid and sulphur- or phosphorus-containing compounds such as proteins and DNA present in the larval body. This explains tissue damage at very low concentrations of nanohybrid. Therefore, this nanoweapon has high potential for field applications.     

Green Synthesis of Silver Nanoparticles Using Exopolysaccharides Produced by Bacillus anthracis PFAB2 and Its Biocidal Property

Journal of Polymers and the Environment - Nowadays when control of environmental toxicity is a matter of concern, the focus of the researchers is to find an eco-friendly process. Considering the...     

Chlorine leakage from bonnet of a valve in a bullet—a case study

This paper deals with the accidental release of chlorine from bonnet of a valve in a bullet installed in a chloro-alkali industry, and the probable causes of the accident and the ensuing sequence of events. Emergency procedures are also discussed. Finally, in the conclusions reached at some useful recommendations, which has been drawn for industrial facilities handling chlorine.