Rituparna Bose

Targeted Delivery of Pesticides Using Biodegradable Polymeric Nanoparticles

In the current scenario the persistent challenge is to produce more food and secure the cultivated food to feed the world. The green revolution has brought tremendous increase in the worldwide crop production. Protecting the growing crop and securing the yielded gains by using pesticide has additionally helped in the production. However, the amazing performance of pesticides has encouraged their excessive use and is now causing accumulation in the environment. It has been found that the residue of pesticides can contaminate soil, water, and through crops can enter the food chain. Over the past few years there has been an increasing pressure from government and regulatory authorities to develop formulations which can have less impact on the environment and be safe for nontargeted species. In this direction, conventional formulations like granules, emulsions, and suspensions are being continuously replaced by novel formulations like microemulsions and multiple-emulsions and further by upcoming nano-formulations. Nano-formulations have the advantage that less quantity of pesticide can be used to target large area and thereby made to exert lesser impact on pesticide accumulation in the environment. Moreover, selection of biologically nontoxic ingredient for nano-formulations can additionally ensure the safety of the products.

Worldwide Pesticide Use

The worldwide consumption of pesticides is about two million tonnes per year: Out of which 45 % is used by Europe alone, 25 % is consumed in the USA, and 25 % in the rest of the world. India’s share is just 3.75 %. The usage of pesticides in Korea and Japan is 6.6 and 12.0 kg/ha, respectively, whereas in India, it is only 0.5 kg/ha.

Can molecular biology and bioinformatics be used to probe an evolutionary pathway

Williamson has proposed an interesting hypothesis regarding the evolution of caterpillars from onycophorans by hybridogenesis “as an addition to Darwins great insight into the generation of diversity ” (1). He has proposed some molecular biology-/ bioinformatics-based experiments to test his theory of hybridogenesis. Although his theory is interesting, we think that the experiments he proposes are too simplistic and will not necessarily shed much light on the topic.

Management of Insect Pests Using Nanotechnology: As Modern Approaches

The above mentioned limitations and less efficiency of traditional methods have led to the development of new and modern approaches for management of insect pest, and this has become the need of the hour. Keeping in the mind the applications of nanotechnology in agriculture, it can be suggested that the use of nanomaterials will result in the development of efficient and potential approaches toward the management of insect pest. However, the literature available on this topic brings to a close conclusion that only a few researchers all over the world are working in this area, and hence, there is a pressing need to apply nanotechnology and this warrants detailed study in this field. Keeping this idea in mind, the research studies carried out (related to management of insect pest) have been reviewed here.

Biological Control of Insect Pests

Natural enemies of insect pests play a key role in reducing the levels of pest populations below those causing economic injury. Both natural and applied biological control tactics can be important in successful management of pest populations. Biological control has the advantage of being self-perpetuating (once established), and it usually does not harm non-target organisms found in the environment. In addition, it is non-polluting or (as disruptive to the environment) as chemical pesticides, nor does it leave residues on food (a concern of many people today). However, the use of biological control does require detailed knowledge of the pest’s biology and the natural enemies associated with the pest and their impact.

Nanoparticulate Delivery Systems

A nanoparticulate system, typically, comprises particles or droplets in the submicron range, i.e., below 1 μm, in an aqueous suspension or emulsion, respectively. This small size of the inner phase gives such a system unique properties in terms of appearance and application. The particles are too small for sedimentation, and they are held in suspension by the Brownian motion of the water molecules. They have a large overall surface area, and their dispersions provide a high solid content at low viscosity.

Nanoparticulate Formulations for Pesticide Applications

The following sections give details of the nanoparticulate formulation developed by various researchers. The innovative technology to formulate the nanoparticle is briefly discussed along the entrapment strategies. Few biological models for testing the efficacy of these developed formulations on insect model have also been included.

A Brief Overview of Nanotechnology

Nanotechnology has emerged in the last decades of the twentieth century with the development of new enabling technologies for imaging, manipulating, and simulating matter at the atomic scale. The frontier of nanotechnology research and development encompasses a broad range of science and engineering activities directed toward understanding and creating improved materials, devices, and systems that can exploit the properties of matter emerging at the nanoscale. The results promise benefits that can shift paradigms in biomedicine (e.g., imaging, diagnosis, treatment, and prevention); energy (e.g., conversion and storage); electronics (e.g., computing and displays); manufacturing; environmental remediation; and many other categories of products and applications.

Materials and Method

Geometric morphometrics is the analysis of geometric landmark coordinates points on specific parts of an organism (Bookstein 1991). Morphometric analyses were based on the use of landmarks to capture shape; landmarks are points representing the same location on each specimen, and can be assigned to three general categories (Bookstein 1991): Type I—discrete juxtapositions (e.g., meeting of three structures), Type II—functional equivalents (e.g., tips of extrusions and maximum curvatures) and Type III—extremal points (e.g., tip of beak). In this study, type I and II landmarks were used, as they are most likely to capture biologically meaningful shape change (Fig. 2.1). When selecting landmarks for analyses, we selected points that characterized not only body shape accurately, but also represent some aspect of the inferred ecological niche. While landmarks were not biologically homologous, they represent discrete points that correspond among forms (sensu Bookstein 1991), which is appropriate for analyses attempting to capture shape changes or function (as opposed to describing phylogenetic relationships). For all individuals, measurements were taken on the entire specimen (brachial and pedicle valve. Once coordinates were obtained, geometric morphometrics were applied to landmarks to convert them into Bookstein shape coordinates (see Bookstein 1991 for a full description of Bookstein shape coordinate equations and methods), thus rotating, translating and scaling all landmarks, while maintaining their geometric relationships; these scaled coordinates were used in all analyses.

Coastal water pollution in two rivers of the Bengal delta

A thorough comprehension of relevant environmental parameters is a prerequisite to preventing coastal degradation and environmental balance in coastal zones. In this study, we correlate major physicochemical of two coastal rivers (Matla and Saptamukhi) in the Sunderban district, West Bengal. The parameters namely: pH, salinity, dissolved oxygen, suspended solids, nitrogen and phosphorus concentrations (inorganic and total) of these two rivers were studied in detail over the 90s decade. We hypothesized that both natural and anthropogenic activities during that time have contributed to the pollution and employed the above parameters to test our hypothesis. Our results reveal that the quality of waters in the rivers have been showed to be dependent on flood impacts, storm surge, eutrophication, domestic sewage, agricultural and industrial wastes. Thus, both natural and anthropogenic causes are the behind coastal pollution of river waters. We conclude that they have all contributed to pollution of these rivers in various ways and we calculate the differential effects of these parameters on coastal pollution.