Do Topical Repellents Divert Mosquitoes Within a\ud Community?

Repellents are compounds which interfere with the mosquito’s olfactory system hindering them to identify their hosts and succeeding in taking a blood-meal [1]. However, repellents do not eliminate the host-seeking mosquitoes, they simply reduce human-vector contact. Consequently, there is a possibility that individuals, who do not use repellents, experience more bites than usual because mosquitoes are diverted from the repellent users. The objective of this study was to measure if diversion occurs from households that use repellents to those that don’t within a community with incomplete topical repellent coverag An interventional study was performed in three villages of southern Tanzania using 15%-DEET (N,N-Diethyl-meta-toluamide) and a placebo lotion. Three coverage scenarios were investigated: complete repellent coverage (all households were given 15%-DEET), incomplete repellent coverage (80% of households were given DEET-15% and 20% were given a placebo lotion) and no repellent coverage (all households were given a placebo lotion). The coverage scenarios were rotated between villages. Mosquito densities were measured through aspiration of indoor and outdoor resting mosquitoes respective to each enrolled household. Data was analysed using mixed-effects models and the no coverage scenario was used as reference. Placebo users living in a village where 80% of the households used 15%-DEET were likely to have nearly three times more mosquitoes (p<0.001) resting in their dwellings in comparison to households in a village where nobody uses repellent (Table 1) There is strong evidence that mosquitoes are diverted between households that use repellent to those that don’t. This study arises questions on health equity associated with repellent usage. Policy makers should take into consideration these results while devising vector control programs, as less privileged individuals are likely to suffer more mosquito bites and therewith be more exposed to vector-borne diseases if universal coverage is not reached

Glassy dynamics of two poly(ethylene glycol) derivatives in the bulk and in nanometric confinement as reflected in its inter- and intra-molecular interactions

The inter- and intra-molecular interactions as they evolve in the course of glassy solidification are studied by broadband dielectric—and Fourier-transform infrared—spectroscopy for oligomeric derivatives of poly(ethylene glycol) derivatives, namely, poly(ethylene glycol) phenyl ether acrylate and poly(ethylene glycol) dibenzoate in the bulk and under confinement in nanoporous silica having mean pore diameters 4, 6, and 8 nm, with native and silanized inner surfaces. Analyzing the spectral positions and the oscillator strengths of specific IR absorption bands and their temperature dependencies enables one to trace the changes in the intra-molecular potentials and to compare it with the dielectrically determined primarily inter-molecular dynamics. Special emphasis is given to the calorimetric glass transition temperature Tg and Tαβ ≈ 1.25Tg, where characteristic changes in conformation appear, and the secondary β-relaxation merges with the dynamic glass transition (α-relaxation). Furthermore, the impact of main chain conformations, inter- and intra-molecular hydrogen bonding, and nanometric confinement on the dynamic glass transition is unraveled

Do topical repellents divert mosquitoes within a community? Health equity implications of topical repellents as a mosquito bite prevention tool.

OBJECTIVES: Repellents do not kill mosquitoes--they simply reduce human-vector contact. Thus it is possible that individuals who do not use repellents but dwell close to repellent users experience more bites than otherwise. The objective of this study was to measure if diversion occurs from households that use repellents to those that do not use repellents. METHODS: The study was performed in three Tanzanian villages using 15%-DEET and placebo lotions. All households were given LLINs. Three coverage scenarios were investigated: complete coverage (all households were given 15%-DEET), incomplete coverage (80% of households were given 15%-DEET and 20% placebo) and no coverage (all households were given placebo). A crossover study design was used and coverage scenarios were rotated weekly over a period of ten weeks. The placebo lotion was randomly allocated to households in the incomplete coverage scenario. The level of compliance was reported to be close to 100%. Mosquito densities were measured through aspiration of resting mosquitoes. Data were analysed using negative binomial regression models. FINDINGS: Repellent-users had consistently fewer mosquitoes in their dwellings. In villages where everybody had been given 15%-DEET, resting mosquito densities were fewer than half that of households in the no coverage scenario (Incidence Rate Ratio [IRR]=0.39 (95% confidence interval [CI]: 0.25-0.60); p<0.001). Placebo-users living in a village where 80% of the households used 15%-DEET were likely to have over four-times more mosquitoes (IRR=4.17; 95% CI: 3.08-5.65; p<0.001) resting in their dwellings in comparison to households in a village where nobody uses repellent. CONCLUSIONS: There is evidence that high coverage of repellent use could significantly reduce man-vector contact but with incomplete coverage evidence suggests that mosquitoes are diverted from households that use repellent to those that do not. Therefore, if repellents are to be considered for vector control, strategies to maximise coverage are required

Alvarado vs Lintula Scoring Systems in Acute Appendicitis

Background: Timely and correct diagnosis of acute appendicitis reduces complications and avoids unnecessary surgeries. Scoring systems are used as adjuncts to aid in diagnosis.Methods: This was a prospective observational study carried out at Kenyatta National Hospital, from November 2014 to April 2015. Demographic, clinical and laboratory data was collected from consenting patients. The gold standard of diagnosis was histopathology. Data analysis was done using SPSS. The receiver operating characteristics, sensitivity, specificity, positive predictive values and negative predictive values of both scoring systems were then calculated for each of the scoring systems and compared between the two.Results: Majority of patients presented with right iliac fossa pain and underwent appendectomy. The sensitivity of the Lintula and Alvarado scoring systems were 60.8% and 84.3% respectively, while the specificity was 60% and 35% respectively. The PPV of the Lintula was 79.5% while that of the Alvarado 76.8%.Conclusion: The Lintula system compares well with the Alvarado system for diagnosis of acute appendicitis and can therefore be employed in situations where laboratory facilities may be limited.Key words: Acute Appendicitis, Scoring systems, Lintula, Alvarad

The Influence Electronic Loan Management System on Loan Performance Amongst Microfinance Institutions in Kenya

This study sought to determine the influence of electronic loan management system on performance of loans in microfinance institutions in Kenya with specificity of Nairobi County where the survey was conducted on microfinance institutions in Nairobi. The study was based on three main variables which included credit scoring system, loan monitoring and credit recovery processes. The study was based on Transactions Cost Innovative Theory. Descriptive research design was employed in the study. Census used because the population was manageable. Regression coefficient from revealed that a unit increase in electronic loan management system would results to a significant increase in Loan performance amongst microfinance institutions in Kenya.Keywords: Electronic loan management system, Microfinance institution, Loan performance. DOI: 10.7176/RJFA/14-10-07 Publication date:May 31st 202

Use of a Semi-field System to Evaluate the Efficacy of Topical Repellents under user Conditions Provides a Disease Exposure free Technique Comparable with Field Data.

Before topical repellents can be employed as interventions against arthropod bites, their efficacy must be established. Currently, laboratory or field tests, using human volunteers, are the main methods used for assessing the efficacy of topical repellents. However, laboratory tests are not representative of real life conditions under which repellents are used and field-testing potentially exposes human volunteers to disease. There is, therefore, a need to develop methods to test efficacy of repellents under real life conditions while minimizing volunteer exposure to disease. A lotion-based, 15% N, N-Diethyl-3-methylbenzamide (DEET) repellent and 15% DEET in ethanol were compared to a placebo lotion in a 200 sq m (10 m x 20 m) semi-field system (SFS) against laboratory-reared Anopheles arabiensis mosquitoes and in full field settings against wild malaria vectors and nuisance-biting mosquitoes. The average percentage protection against biting mosquitoes over four hours in the SFS and field setting was determined. A Poisson regression model was then used to determine relative risk of being bitten when wearing either of these repellents compared to the placebo. Average percentage protection of the lotion-based 15% DEET repellent after four hours of mosquito collection was 82.13% (95% CI 75.94-88.82) in the semi-field experiments and 85.10% (95% CI 78.97-91.70) in the field experiments. Average percentage protection of 15% DEET in ethanol after four hours was 71.29% (CI 61.77-82.28) in the semi-field system and 88.24% (84.45-92.20) in the field. Semi-field evaluation results were comparable to full-field evaluations, indicating that such systems could be satisfactorily used in measuring efficacy of topically applied mosquito repellents, thereby avoiding risks of exposure to mosquito-borne pathogens, associated with field testing

Enhancement of Security in RFID using RSA Algorithm

A huge revolution has occurred in Radio Frequency Identification (RFID) technologies during the past decades. More vendors are involved, and have invested in this technology, which promises wholesale changes across a broad spectrum of business activities. Currently, RFID systems are usually available in low, high, ultra-high, and microwave frequencies with passive, semi-passive (or semi-active) and active transponders or tags. Tags might be either Chipless, or contain a microchip with read only, or read and write memory. The component controlling communication in a RFID system is called a reader or interrogator, which can be stationary or portable depending on the application. In order for the tags to transmit their data, the tags must be in the reader’s field or interrogation zone, and receive the necessary energy (in form of radio waves) from the reader. Although promising, RFID is not without its challenges, which arise from both a technological and usage point of View (IT Pro, 2005).  A common concern with RFID is data security. Data Security is a key area in RFID usage, it determines wholly whether this technology will be adopted fully especially in this part of the world (Eastern and Central Africa) for business processes and automation. For this technology to be utilized fully and realized then the users of the system MUST be assured of their data’s security.People who use devices that carry personal financial information, such as credit card or other ID numbers, do not want others to access their accounts. These are significant security vulnerabilities in RFID. Some researchers have proposed schemes that would require tags to authenticate readers, thus transmitting information only to authorized readers.This research paper addresses the security challenge in RFID by proposing RSA algorithm as a viable solution to encrypt data over transmission and also authenticate the reader and the tags. Keywords: RFID, Security, authenticate, Data Security