Spatial analysis of wing geometry in dengue vector mosquito, aedes aegypti (L.) (diptera: Culicidae), populations in Metropolitan Manila, Philippines

Background & objectives: Aedes aegypti (L.) is an efficient vector for arboviral diseases such as dengue. The wings of Ae. aegypti has been extensively studied in order to investigate population heterogeneity and structure by utilizing a landmark based geometric morphometrics (GMs) approach. The aim of this study was to examine and assess the wing geometry of Ae. aegypti in Metropolitan Manila. Methods: In total, 312 Ae. aegypti mosquitoes were collected from 98 sampling points using a mosquito light-trap from May 2014 to January 2015. A complete coverage of the wing was achieved by removing wing scales with chemical and physical treatment, leading to identification of 26 landmarks. Geometric morphometric analyses were employed and the spatial distance pattern was estimated using isolation by distance (IBD) and spatial autocorrelation (SA). Results: The results of the GM analyses revealed population heterogeneity and structuring in Ae. aegypti populations for both sexes using principal component and canonical variate analyses respectively. Moreover, IBD and SA only detected significant spatial structure in male Ae. aegypti populations while female population structures were homogeneous throughout the geographical area. Interpretation & conclusion: The newly modified wing preparation procedure was able to capture a complete coverage of the wings of Ae. aegypti, thus providing a stronger separation power for very close populations in an urban area. It is also noteworthy that the results of IBD and SA supported the findings of GM in the population structuring of male and female Ae. aegypti. The outcome of the study increases our understanding of the vector, which would be useful in developing effective control strategies. © 2016, Malaria Research Center. All rights reserved

Systematic review of Carrageean hydrogels : drug delivery system for controlled-release

The methodological and analytical approach of the researchers were based on the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) Statement in order to assess the eligibility of chosen literature based on the aim of the study and the the chosen studies were selected through the used of databases and Boolean operators that fit the chosen criteria. Studies regarding the rate of absorption, the onset of action, duration of action and the Nano composites of carrageenan were gathered. Several studies have shown that the use of carrageenan increases the rate of absorption of the drug through excellent mechanical, swelling and absorption properties. Carrageenan can also increase the porosity of hydrogel which is directly proportional to the diffusion of drugs but up to a certain extent because very high porosity would not translate to higher drug release. Studies have stated that high pH of the media can lead to a higher release of drug content. A concentration of the carrageenan gels can also effect the sustained release increasing the encapsulation efficiency and may cause burst effect of the drug, which in turn is responsible for sustaining drug release in a prolonged period of time. Studies have also mentioned that carrageenan may enhance the bioavailability of the drug. Lastly, for the Nano composites, kappa-carrageenan can be used as an ideal drug delivery for controlled-release of drugs as it is considered thermoreversible and provides a more stable swelling behavior