Bionomics of Anopheles fluviatilis and Anopheles culicifacies (Diptera: Culicidae) in Relation to Malaria Transmission in East-Central India

The southern districts of Odisha State in east-central India have been highly endemic for falciparum malaria for many decades. However, there is no adequate information on the abundance of the vector species or their bionomics in relation to space and time in these districts. Therefore, a study was carried out on the entomological aspects of malaria transmission to generate such information. Collections of mosquitoes were made once during each of the three seasons in 128 villages selected from eight districts. Villages within the foot-hill ecotype had a significantly greater abundance of Anopheles fluviatilis James s. l., whereas the abundance of Anopheles culicifacies Giles s. l. was significantly greater in the plain ecotype. The abundance of An. fluviatilis was maximum during the cold season, whereas An. culicifacies abundance was highest during summer and rainy seasons. The maximum likelihood estimation of the malaria infection rate in An. fluviatilis was 1.78%, 6.05%, and 2.6% in Ganjam, Kalahandi, and Rayagada districts, respectively. The infection rate of An. culicifacies was 1.39% only in Kandhamal district; infected females were not detected elsewhere. Concurrently, the annual malaria parasite incidence (MPI) was significantly higher in hill-top (17.6) and foot-hill (14.4) villages compared to plain villages (4.1). The districts with more villages in hill-top and foot-hill ecotypes also had a greater abundance of An. fluviatilis, the major malaria vector, and exhibited a higher incidence of malaria than villages within the plain ecotype, where An. culicifacies was the most abundant vector.

Evolutionary Algorithm-Based Multi-objective Control Scheme for Food Drying Process

Food drying is one of the important methods to prevent microbial growth during preservation. However, it is a complex non-linear process where the quality of the food depends on environmental conditions. Therefore, food drying must be carried out under controlled environment. In this paper, an internal model control (IMC) scheme is developed for pineapple drying using the evolutionary algorithms namely: genetic algorithm (GA) and particle swarm optimization (PSO) to achieve the desired quality (single objective). In order to reduce the control effort and hence the cost, without compromising the desired quality, a multi-objective control scheme is also formulated using weighted sum method. The closed loop performance of the control scheme for GA-based IMC-PI controller and PSO-based IMC-PI controller are analyzed for servo and regulatory operations. The results thus obtained are compared both qualitatively and quantitatively. From the simulation results it is observed that PSO-based IMC-PI controller gives better performance and better range of the temperature compared to the other control schemes.

Nanoscale organization of hedgehog is essential for long-range signaling

Hedgehog (Hh) plays crucial roles in tissue-patterning and activates signaling in Patched (Ptc)-expressing cells. Paracrine signaling requires release and transport over many cell diameters away by a process that requires interaction with heparan sulfate proteoglycans (HSPGs). Here, we examine the organization of functional, fluorescently tagged variants in living cells by using optical imaging, FRET microscopy, and mutational studies guided by bioinformatics prediction. We find that cell-surface Hh forms suboptical oligomers, further concentrated in visible clusters colocalized with HSPGs. Mutation of a conserved Lys in a predicted Hh-protomer interaction interface results in an autocrine signaling-competent Hh isoform--incapable of forming dense nanoscale oligomers, interacting with HSPGs, or paracrine signaling. Thus, Hh exhibits a hierarchical organization from the nanoscale to visible clusters with distinct functions.

Native and modeled disulfide bonds in proteins: knowledge-based approaches toward structure prediction of disulfide-rich polypeptides

Structure prediction and three-dimensional modeling of disulfide-rich systems are challenging due to the limited number of such folds in the structural databank. We exploit the stereochemical compatibility of substructures in known protein structures to accommodate disulfide bonds in predicting the structures of disulfide-rich polypeptides directly from disulfide connectivity pattern and amino acid sequence in the absence of structural homologs and any other structural information. This knowledge-based approach is illustrated using structure prediction of 40 nonredundant bioactive disulfide-rich polypeptides such as toxins, growth factors, and endothelins available in the structural databank. The polypeptide conformation could be predicted in 35 out of 40 nonredundant entries (87%). Nonhomologous templates could be identified and models could be obtained within 2 A deviation from the query in 29 peptides (72%). This procedure can be accessed from the World Wide Web (http://www.ncbs.res.in/ approximately faculty/mini/dsdbase/dsdbase.html).

Reappearance of Anopheles minimus in Singhbum hills of East-Central India

Anopheles minimus, an important malaria vector of South East Asia, has reappeared in the Singhbum hills, East-Central India where deforestation and DDT residual spraying had reportedly eliminated it during the Malaria Eradication Programme. The species reported has been identified as sibling species A of the An. minimus complex. An. minimus is susceptible to both deltamethrin and DDT. The study shows that the environmental conditions in this region still favour the existence of the species and one of the possible reasons for its reappearance may be the scaling down of residual insecticide spraying in the area.

Detection of Brugia malayi in laboratory and wild-caught Mansonioides mosquitoes (Diptera: Culicidae) using Hha I PCR assay

An Hha 1 based polymerase chain reaction (PCR) assay developed for the detection of Brugia malayi, the causative agent of Brugian lymphatic filariasis, was evaluated for its sensitivity in the laboratory and for its usefulness in measuring changes in transmission of the disease in the field. Laboratory studies showed that the new assay was highly sensitive in comparison with the standard dissection and microscopy technique. The assay can detect as little as 4 pg of parasite DNA or a single microfilaria in pools of up to 100 mosquitoes. The optimum pool size for convenience was found to be 50 mosquitoes per pool. The efficacy of PCR assay was evaluated in filariasis control programmes in operation in endemic areas of Kerala State, South India. The infection rates obtained by the Hha I PCR assay and the conventional dissection and microscopy technique were 1.2% and 1.7% respectively in operational areas and 8.3% and 4.4% respectively, in check areas, which were not significantly different (P < 0.05). Thus, the Hha I PCR assay was found to be as sensitive as the conventional technique and hence it can be used as a new epidemiological tool for assessing parasite infection in field-collected mosquitoes.

rDNA-ITS2 polymerase chain reaction assay for the sibling species of Anopheles fluviatilis

Species-specific differences in the nucleotide sequences of the second internal transcribed spacer (ITS2) region of the ribosomal DNA (rDNA) were used to develop a diagnostic polymerase chain reaction (PCR) assay for two of the sibling species of the Anopheles fluviatilis complex, members of which are major vectors of malaria in central and northern parts of India. This assay consisted of a three primer reaction, which could amplify the DNA of both the species producing fragments of two distinct sizes, 350 bp for species X and 450 bp for species Y, respectively. The assay was found to be highly specific and sensitive.