Cost-effective Control Strategies Research Articles

Determinants of Cervical Cancer Screening Uptake among Women in Orlu Local Government Area, Imo State, Nigeria.

Background: Cervical cancer is the 2nd commonest cancer among women worldwide and is the leading cause of cancer deaths among women in developing countries. Optimal cervical cancer screening uptake is one of the most cost effective control strategies for the disease. Objectives: To assess the determinants of cervical cancer screening uptake among women in Orlu Local Government Area, Imo State, Nigeria. Materials & Methods: A community based cross-sectional study with the use of 502 interviewer-administered questionnaires was conducted among women in Orlu Local Government Area of Imo State. All the women in the community attending the annual 2018 August meeting were recruited for this study. Results:The study showed that the mean age of the respondents was 42±2.8 years. Furthermore, 82.3% of respondents attained postsecondary school educational level. Also 80.5% of respondents have heard about cervical cancer screening but level of cervical cancer screening uptake was very low among the respondents (13.5%). Significant associations were found between embarrassment, lack of symptoms, lack of physician request, lack of counselling, cost, unavailability of services and cervical cancer screening uptake. Conclusion: Despite the high knowledge of cervical cancer screening among women in Orlu LGA, uptake of cervical cancer screening was low. Enhancing health education and provision of free and widely accessible health screening services may increase uptake among these women. Key words: Cervical cancer, screening, Orlu women, uptake.

The Cost-Effectiveness Analysis and Optimal Strategy of the Tobacco Control.

This paper aims at investigating how the media coverage and smoking cessation treatment should be implemented, for a certain period, to reduce the numbers of smokers and patients caused by smoking while minimizing the total cost. To this end, we first propose a new mathematical model without any control strategies to investigate the dynamic behaviors of smoking. Furthermore, we calculate the basic reproduction number ℛ0 and discuss the global asymptotic stabilities of the equilibria. Then, from the estimated parameter values, we know that the basic reproduction number ℛ0 is more than 1, which reveals that smoking is one of the enduring problems of the society. Hence, we introduce two control measures (media coverage and smoking cessation treatment) into the model. Finally, in order to investigate their effects in smoking control and provide an analytical method for the strategic decision-makers, we apply a concrete example to calculate the incremental cost-effectiveness ratios and analyze the cost-effectiveness of all possible combinations of the two control measures. The results indicate that the combination of media coverage and smoking cessation treatment is the most cost-effective strategy for tobacco control.

Performance Investigation of Three-Phase Three-Switch Direct PWM AC/AC Voltage Converters

Reducing the number of active switches is substantial for obtaining a simple, reliable, high-efficiency, and cost-effective AC/AC voltage converter. In this paper, two topologies of three-phase direct PWM AC/AC voltage converter are proposed. The first is for the buck converter and the other is for the boost one. Each converter has no DC energy storage elements and employs only three IGBTs. The proposed converters do not use lossy snubber circuits and have not commutation problems. A simple, reliable, and cost-effective control strategy, which employs only one voltage sensor, is also proposed. Using a closed-loop voltage control technique, two complementary PWM gate signals are generated to drive the three active switches of each converter. Adjusting the duty ratio of PWM gate signals regulates the output voltage of the AC/AC converters. Operating principle and mathematical analysis of the converters are presented. Voltage stresses across active and passive semiconductor switches of the proposed converters are derived. Small signal analysis based on complex DQ transformed equivalent circuits of the converter is introduced. Voltage controller design using frequency response analysis is provided. The converters are simulated using MATLAB/SIMULINK and laboratory prototypes are implemented in real-time using DSP-DS1104 control board. The converters are tested under different operating conditions and their performances are investigated and compared. The symmetry of the output voltage/current is examined by the theory of symmetrical components. The simulation and experimental results are in a close agreement. This confirms the validity of the theoretical analysis, the effectiveness of the control strategy, and the feasibility of the proposed converters.

Adherence to Iron-Folate Supplementation and Associated Factors among Pastoralist's Pregnant Women in Burji Districts, Segen Area People's Zone, Southern Ethiopia: Community-Based Cross-Sectional Study.

Background Iron deficiency anemia among pregnant women is one of the most common public health problems in developing country particularly in Ethiopia. Iron/folic acid supplementation with optimal adherence is the main cost-effective strategy for prevention and control of iron deficiency anemia in pregnant women. However, level of adherence to iron/folic acid supplementation and its associated factors were not well identified in study area. Therefore, the aim of this study was to determine the level of adherence to iron/folic acid supplementation and associated factors among pregnant women in Burji Districts, southern Ethiopia. Methods A community-based cross-sectional study was conducted among 317 pregnant women in Burji Districts from March to April 2017 using interviewer administered questionnaires. Data were entered into Epi Info 3.5.1 and exported to SPSS version 20.0 for analysis. Binary and multivariable logistic regression was used to identify factors associated with iron/folic acid supplementation. Adjusted odds ratio (AOR) with 95% confidence interval (CI) and p-value <0.05 were used to declare statistical significance. Results Among women participating in the study, 163(51.4%) were adherent to iron/folate acid supplementation. Factors significantly associated with adherence to iron and folic acid supplementation were maternal educational status (AOR: 2.47, 95% CI: 1.13-4.97), early registration for ANC (AOR: 2.49, 95% CI: 1.45 – 4.27), history of anemia during current pregnancy (AOR: 2.02, 95% CI: 1.09-3.72), and knowledge about iron and folic acid supplementation (AOR: 1.96, 95% CI: 1.02-3.76). Forgetfulness and fear of side effects were among the leading reasons of pregnant women for nonadherence to iron and folic acid supplementation. Conclusions This study revealed that adherence to iron /folic acid supplementation was found to be 51.4%. Maternal educational status, early registration for ANC, history of anemia during current pregnancy, and knowledge about iron and folic acid supplementation were significant factors associated with adherence to iron/folic acid supplementation among pastoralist's pregnant women. Therefore, anemia prevention strategy should include strengthening giving awareness, counseling, strengthening community health education, and participation in health programs which are necessary to improve the uptake of iron/folic acid supplements.

Epidemiological study of Middle East respiratory syndrome coronavirus infection in dromedary camels in Saudi Arabia, April-May 2015.

A cross-sectional study was conducted in five regions in Saudi Arabia to investigate the epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in dromedary camels (Camelus dromedarius) during April and May2015. Serum and nasal swab samples were tested for MERS-CoV antibodies andribonucleic acid (RNA) using a recombinant enzyme-linked immunosorbent assay (rELISA) and real-time reverse-transcription polymerase chain reaction (rRT-PCR), respectively. The overall MERS-CoV antibody seroprevalence was 80.5%, whereas the overall viral RNA prevalence was 2.4%. The associations of risk factors with each prevalence were quantified using univariate and multivariate analyses. The multivariate models identified region, age, grazing system, exposure to wild animals and dung removal as factors significantly associated with seroprevalence (p ??0.05). A higher seroprevalence was more likely to occur in camels from the Riyadh, Eastern, Northern and Makkah regions than those from the Jazan region; camels ??4 and 1-3 years of age (marginally significant) than calves < 1 year; and camels raised in zero grazing and semi-open grazing systems than those raised in an open grazing system. However, the presence of wild animals and daily dung removal were negatively associated with seroprevalence. On the other hand, region and sex were significantly associated with MERS-CoV RNA prevalence(p ??0.05). A higher viral RNA prevalence was more likely to occur in camels from the Riyadh region and Eastern region (marginally significant) than in those from the Makkah region, and in male camels than female camels. In conclusion, the risk factors identified in this study can be considered to be predictors of MERS-CoV infection in camels and should be taken into account when developing an efficient and cost-effective control strategy.

Diacetyl control during brewery fermentation via adaptive laboratory engineering of the lager yeast Saccharomyces pastorianus

Diacetyl contributes to the flavor profile of many fermented products. Its typical buttery flavor is considered as an off flavor in lager-style beers, and its removal has a major impact on time and energy expenditure in breweries. Here, we investigated the possibility of lowering beer diacetyl levels through evolutionary engineering of lager yeast for altered synthesis of α-acetolactate, the precursor of diacetyl. Cells were exposed repeatedly to a sub-lethal level of chlorsulfuron, which inhibits the acetohydroxy acid synthase responsible for α-acetolactate production. Initial screening of 7 adapted isolates showed a lower level of diacetyl during wort fermentation and no apparent negative influence on fermentation rate or alcohol yield. Pilot-scale fermentation was carried out with one isolate and results confirmed the positive effect of chlorsulfuron adaptation. Diacetyl levels were over 60% lower at the end of primary fermentation relative to the non-adapted lager yeast and no significant change in fermentation performance or volatile flavor profile was observed due to the adaptation. Whole-genome sequencing revealed a non-synonymous SNP in the ILV2 gene of the adapted isolate. This mutation is known to confer general tolerance to sulfonylurea compounds, and is the most likely cause of the improved tolerance. Adaptive laboratory evolution appears to be a natural, simple and cost-effective strategy for diacetyl control in brewing.

A systematic approach for selecting an optimal strategy for controlling VOCs emissions in a petrochemical wastewater treatment plant

This study assessed the fate of benzene, toluene, and styrene in a full-scale petrochemical wastewater treatment plant (WWTP) with respect to the selection of an efficient and cost-effective control strategy. To prepare input parameters for TOXCHEM, wastewater samples were collected from the inlet of treatment units. Subsequently, the resultant emission rates were applied in AERMOD to study the dispersion patterns of the target volatile organic compounds (VOCs). Based on the TOXCHEM results, the overall emission of benzene, toluene, and styrene was 123,935 g/day, of which 73.4, 13.3, and 13.4% were benzene, toluene, and styrene, respectively. The results indicated that up to 99.5% of the target VOCs were removed from wastewater by volatilization and biodegradation mechanisms. Also, more than 85% of the VOCs emission occurred from the primary treatment units (American Petroleum Institute oil separator, equalization basin, and dissolved air flotation system). In some cases, the concentration distribution profiles resulting from AERMOD showed higher values than EPA reference concentrations (RfC) around the study area. The most affected area was near the WWTP with maximum 1-h concentrations of 8166, 1267, and 1228 μg/m3 of benzene, toluene, and styrene, respectively. Based on the modeling results, the most applicable and available methods for separating and ultimately disposing of VOCs were investigated and compared with the aim of reducing emission rates to meet ambient air quality standards. The results revealed that steam stripping is the most efficient and cost-effective VOCs control strategy in the studied plant. Moreover, thermal incineration was marked as the first choice for ultimate disposal of the contaminated air streams.

Spread of Zika virus disease on complex network—A mathematical study

Zika virus epidemic poses a major threat to public health globally. Initially, this disease was limited to Africa but now it is spreading throughout the World. It is well known that zika virus is transmitted to human by the bites of Aedes mosquitoes. Recently, there are reported cases of sexual transmission and transmission due to blood transfusion in many countries e.g., Argentina, France, New Zealand, USA etc. In this paper a mathematical model of Zika virus on complex network is formulated and analyzed keeping in mind both mosquito-borne and sexual transmission of this disease. The existence and global stability of disease-free equilibrium are discussed in detail. The basic reproduction number R0 of the model is computed and it is found that for R0<1, the disease-free equilibrium of the model is globally asymptotically stable under some condition. In addition to this the final size relation of the proposed model is also computed. The key parameters of the model are computed using curve fitting to the real data by least-square method. Sensitivity analysis and numerical simulation are also performed for our proposed model. Finally, this model is extended to optimal control problem, to find the suitable cost-effective and time-dependent control strategies to reduce the number of infectives in a desired interval of time.

Temporal analysis of the interference caused by paratuberculosis vaccination on the tuberculosis diagnostic tests in goats

Vaccination against paratuberculosis (PTB) in goats is a cost-effective control strategy, and is also effective as regards preventing the onset of clinical cases. However, it causes interference in the diagnostic tests used in the control of tuberculosis (TB). A group of 99 goats from a herd with no history of TB or PTB infection was vaccinated against PTB at seven months of age. They then underwent consecutive intradermal tests [single (SIT) and comparative (CIT) intradermal tuberculin tests), interferon-gamma release assays (IGRA) and two serological tests (p22_CE and DR-ELISA) every three months, until the interference disappeared. When using the SIT test, a variable number of positive reactors were observed at 3 months (T3; 32.3%, 95% CI 23.9–42.1), 6 months (T6; 11.5%, 95% CI 6.5–19.4), 9 months (T9; 6.4%, 95% CI 3.0–13.2) and 12 months (T12; 0%, 95% CI 0–4.0) post-vaccination. In contrast, the CIT test had a specificity (Sp) of 100% (95%, CI 96.0–100, regardless of the time post-vaccination. The IGRA also obtained high Sp values throughout the study period. No significant interference in the serological tests was recorded at T3 [p22_CE, Sp = 96% (95% CI 90.1–98.4) and DR-ELISA, Sp = 98% (95% CI 92.9–99.4)], although an increase in antibody titers was observed in the following herd testing events. In conclusion, the use of the SIT test causes the onset of false-positive reactors if applied before 12 months post-vaccination in a TB-free/PTB-vaccinated herd. Nevertheless, the CIT test and IGRA obtained high Sp values under these epidemiological circumstances. The serological tests were also highly specific in the case of PTB-vaccinated goats, although their Sp decreased significantly after several intradermal tests.

Unique solvability of a singular stochastic control model for population management

We present and mathematically analyze a singular stochastic control model for cost-effective and ecologically-sound indirect population control strategy for fish-eating birds. Finding the optimal strategy of a threshold type reduces to solving a variational inequality. We prove the unique existence of its viscosity solution that is neither convex nor concave, which turns out to be a classical solution. Comparative statics on the optimal threshold is performed as well to demonstrate practical implications of the model.

An Active Seat Controller with Vehicle Suspension Feedforward and Feedback States: An Experimental Study

Active seat suspensions can be used to reduce the harmful vertical vibration of a vehicle’s seat by applying an external force using a closed loop controller. Many of the controllers found in the literature are difficult to implement practically, because they are based on using unavailable or difficult and costly measurements. This paper presents both simulation and experimental studies of five novel, simple, and cost-effective control strategies to be used for an active seat suspension in order to improve ride comfort at low frequencies below 20 Hz. These strategies use available and measurable feedforward (preview) information states from the vehicle secondary suspension, as well as feedback states from the seat suspension, together with gains optimised to minimise the occupant vibration. The gains were optimised using a genetic algorithm (GA), with a fitness function based on the seat effective amplitude transmissibility (SEAT) factor. Constraints on the control force and the seat suspension stroke were also included in the optimisation algorithm. Simulation and laboratory experimental tests were carried out to assess the performance of the proposed controllers according to the ISO 2631-1 standard, in both the frequency and time domains with a range of different road profiles. The experimental tests were performed using a multi-axis simulation table (MAST) and a physical active seat suspension configured as a hardware-in-loop (HIL) simulation with a virtual linear quarter vehicle model (QvM). The results demonstrate that the proposed controllers substantially attenuate the vertical vibration at the driver’s seat compared with both a passive and a proportional-integral-derivative (PID) active seat suspension and thus improve ride comfort together with reducing vibration-linked health risks. Moreover, experimental results show that employing both feedforward information and feedback vehicle body and seat acceleration signals in the controller provides isolation performance gains of up to 19.5 dB over the human body sensitivity frequency range and improves the ride comfort in terms of the SEAT factor and the weighted root mean square (RMS) seat acceleration by at least 25% when compared with a passive system, irrespective of vehicle forward speed.

Cost distribution of bluetongue surveillance and vaccination programmes in Austria and Switzerland (2007–2016)

Bluetongue virus (BTV) is an emerging transboundary disease in Europe, which can cause significant production losses among ruminants. The analysis presented here assessed the costs of BTV surveillance and vaccination...

Appling the One-Class Classification Method of Maxent to Detect an Invasive Plant Spartina alterniflora with Time-Series Analysis

Spartina alterniflora has become the main invasive plant along the Chinese coast and now threatens the local ecological environment. Accurately monitoring the distribution of S. alterniflora is urgent and essential for developing cost-effective control strategies. In this study, we applied the One-Class Classification (OCC) methods of Maximum entropy (Maxent) and Biased Support Vector Machine (BSVM) based on Landsat time-series imagery to detect the species on the middle coast of Jiangsu in east China. We conducted four experimental setups (i.e., single-scene analysis, time-series analysis, Normalized Difference Vegetation Index (NDVI) time-series analysis and a compressed time-series analysis), using OCC methods to recognize the species. Then, we tested the performance of a compressed time-series model for S. alterniflora detection and evaluated the expansibility of this approach when it was applied to a larger region. Our principal findings are as follows: (1) Maxent and BSVM performed equally well, and Maxent appeared to have a more balanced performance over the summer months; (2) the Maxent model with the Default Parameter Set (Maxent-DPS) showed a slightly higher accuracy and more overfitting than Maxent with the Akaike Information Criterion corrected for small samples sizes (AICc)-selected parameter set model, but a t-test found no significant difference between these two settings; (3) April and December were deemed to be important periods for the detection of S. alterniflora; (4) a compressed time-series analysis model—including only three variables (December NDVI, March green and the third Principal Component in January, PC3)—yielded higher accuracy than single-scene analyses, which indicated that time-series analysis can better detect S. alterniflora than single-scene analyses; and (5) the Maxent model using the reconstructed optimal variables and 70 training samples over a larger region produced encouraging results with an overall accuracy of 90.88% and a Kappa of 0.78. The one-class classification method combined with a phenology-based detection strategy is therefore promising for the application of the long-term detection of S. alterniflora over extended areas.

The contribution of respiratory pathogens to fatal and non-fatal respiratory hospitalizations: a pilot study of Taqman Array Cards (TAC) in Kenya

BackgroundRespiratory diseases cause substantial morbidity and mortality worldwide, with sub-Saharan Africa bearing the greatest burden. Identifying etiologies of respiratory disease is important to inform cost effective treatment, prevention and control strategies. Testing for all of the different pathogens that are potentially associated with respiratory illnesses is challenging. We piloted the use of a multi-pathogen respiratory Taqman Array Cards (TAC) to identify pathogens in respiratory samples collected from non-fatal and fatal cases and their matched asymptomatic controls.MethodsThis is a case control study comparing viral and bacterial pathogens detected among non-fatal and fatal cases to those detected among age and time matched asymptomatic controls. We used McNemar’s test to compare proportions of pathogens detected among cases (non-fatal and fatal) to their matched asymptomatic controls. We used Mann-Whitney test to compare the distribution of median Cycle threshold (Ct) values among non-fatal and fatal cases to their corresponding asymptomatic controls.ResultsThere were 72 fatal and 72 non-fatal cases matched to 72 controls. We identified at least one pathogen in 109/144 (76%) cases and 59/72 (82%) controls. For most pathogens, the median Ct values were lower among cases (fatal and non-fatal) compared to asymptomatic controls.ConclusionsSimilar rates of pathogen detection among cases and controls make interpretation of results challenging. Ct-values might be helpful in interpreting clinical relevance of detected pathogens using multi-pathogen diagnostic tools.

Effects of Promotional Materials on Attitudes and Fear towards Colorectal Cancer Screening among Chinese Older Adults: An Experimental Study.

Colorectal cancer (CRC) screening is a cost-effective prevention and control strategy. However, the promotion of CRC screening for older adults may be difficult because reading CRC prevention information may evoke embarrassment, fear, and anxiety towards the screening procedure and cancer diagnosis. This study aims to (1) examine the effects of three promotional materials for CRC screening on the attitudes toward CRC screening tests (screening interest, screening effectiveness, and trust in the screening results) and cancer fear, and (2) to explore the interaction effect of cancer fear with screening effectiveness and trust in the screening results on screening interest of the three screening tests (fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy) among Chinese older adults. A total of 114 community-dwelling older adults were asked to look at the corresponding promotional materials (pamphlet, cartoon, and video) of one of the three study groups. The pamphlet and video represent convention strategies and the cartoon represents an innovative strategy. No significant difference was observed in the screening interest and cancer fear across groups. FOBT was the most preferred screening modality. The video group has a large proportion agreed screening effectiveness of flexible sigmoidoscopy than pamphlet and cartoon groups and trusted in the screening results for FOBT and flexible sigmoidoscopy than the pamphlet group. Logistic regression results showed that the effect of trust in the screening results on screening interest for colonoscopy was greater among participants with higher cancer fear than those with lower cancer fear level. In conclusion, the three promotional groups had produced similar results in their attitudes toward CRC screening and cancer fear. The use of cartoons may be a comparable approach with conventional methods in the promotion of CRC screening. Additional components that can arouse fear and boost response efficacy simultaneously might also be useful for the effective promotion of colonoscopy among Chinese older adults.

Approaches to Vaccination Among Populations in Areas of Conflict.

Vaccination is an important and cost-effective disease prevention and control strategy. Despite progress in vaccine development and immunization delivery systems worldwide, populations in areas of conflict (hereafter, “conflict settings”) often have limited or no access to lifesaving vaccines, leaving them at increased risk for morbidity and mortality related to vaccine-preventable disease. Without developing and refining approaches to reach and vaccinate children and other vulnerable populations in conflict settings, outbreaks of vaccine-preventable disease in these settings may persist and spread across subnational and international borders. Understanding and refining current approaches to vaccinating populations in conflict and humanitarian emergency settings may save lives. Despite major setbacks, the Global Polio Eradication Initiative has made substantial progress in vaccinating millions of children worldwide, including those living in communities affected by conflicts and other humanitarian emergencies. In this article, we examine key strategic and operational tactics that have led to increased polio vaccination coverage among populations living in diverse conflict settings, including Nigeria, Somalia, and Pakistan, and how these could be applied to reach and vaccinate populations in other settings across the world.

English

A study by qualitative fecal examination of 384 fecal samples (201 sheep and 183 goats) was conducted from November 2011 to April 2012 with the objective to determine the major gastrointestinal (GIT) nematodes of small ruminants and their prevalence in sheep and goats in Guto Gida District. The study showed that 186 (92.5%) sheep and 150 (81.97%) goats were found to harbor eggs of GIT nematodes. Both sheep and goats were infected with identical parasites species, but with different level of infection. The six genera of nematodes were identified with prevalence of 21.87, 14.87, 12.5, 10.67, 11.19 and 7.29% for Haemonchus, Trichostrongylus, Trichuris, Oesophagostomum, Bunostumum and Strongloides, respectively. There was a significant difference (p<0.05) in the prevalence of GIT nematodes between sex and species of animals but not for different age group. The study showed that GIT nematodes are major problems of small ruminants in the study area. Therefore, comprehensive study on GIT nematodes, cost effective control strategy and awareness creation to the farmers should be instituted in the area. Key words: Sheep, goats gastrointestinal nematodes, Guto Gida District, Nekemte.

Implications of the cattle trade network in Cameroon for regional disease prevention and control

Movement of live animals is a major risk factor for the spread of livestock diseases and zoonotic infections. Understanding contact patterns is key to informing cost-effective surveillance and control strategies. In West and Central Africa some of the most rapid urbanization globally is expected to increase the demand for animal-source foods and the need for safer and more efficient animal production. Livestock trading points represent a strategic contact node in the dissemination of multiple pathogens. From October 2014 to May 2015 official transaction records were collected and a questionnaire-based survey was carried out in cattle markets throughout Western and Central-Northern Cameroon. The data were used to analyse the cattle trade network including a total of 127 livestock markets within Cameroon and five neighboring countries. This study explores for the first time the influence of animal trade on infectious disease spread in the region. The investigations showed that national borders do not present a barrier against pathogen dissemination and that non-neighbouring countries are epidemiologically connected, highlighting the importance of a regional approach to disease surveillance, prevention and control. Furthermore, these findings provide evidence for the benefit of strategic risk-based approaches for disease monitoring, surveillance and control, as well as for communication and training purposes through targeting key regions, highly connected livestock markets and central trading links.

Modeling spatial patterns of traffic emissions across 5570 municipal districts in Brazil

Traffic emissions pose a major environmental threat to human health in many countries. Most studies of traffic emissions have applied spatial models to achieve more accurate exposure assessments. Spatial analysis is a technique that takes into account various geographic phenomena, providing data that can be communicated to potentially affected people and government agencies considering policies to reduce exposure and adverse health effects. In Brazil, only a few studies have evaluated air pollution and no studies have conducted a spatial analysis of traffic emissions across the entire country. Brazil is a large continental region with 200 million inhabitants, where traffic emissions present a critical health challenge. In this study, we used three geostatistical approaches (Getis-Ord Gi*, K means, and spatial regression) to assess the spatial patterns of traffic emissions for all 5570 municipal districts in Brazil. We identified five groups of municipal districts (spatial clusters) with distinct patterns of traffic emissions based on six variables: population, gross domestic product, urbanization rate, length of highways, human development index, and distance from the state capital. One group represents municipal districts in the Northeast and Northwest regions, which have lower income, traffic, and emissions. In contrast, the others groups represent regions with high income, traffic, and emissions. Finally, we found a significant association between emissions inventories and the six variables used to evaluate spatial clusters. Our results can help inform the design of targeted, cost effective air pollution control strategies to reduce the adverse health effects of traffic emissions in developing countries.

Optimal control and cost-effective analysis of malaria/visceral leishmaniasis co-infection.

In this paper, a deterministic model involving the transmission dynamics of malaria/visceral leishmaniasis co-infection is presented and studied. Optimal control theory is then applied to investigate the optimal strategies for curtailing the spread of the diseases using the use of personal protection, indoor residual spraying and culling of infected reservoirs as the system control variables. Various combination strategies were examined so as to investigate the impact of the controls on the spread of the disease. And we investigated the most cost-effective strategy of all the control strategies using three approaches, the infection averted ratio (IAR), the average cost-effectiveness ratio (ACER) and incremental cost-effectiveness ratio (ICER). Our results show that the implementation of the strategy combining all the time dependent control variables is the most cost-effective control strategy. This result is further emphasized by using the results obtained from the cost objective functional, the ACER, and the ICER.