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Massive multiple-input multiple-output (MIMO) is considered to be an emerging technique in wireless communication systems, as it offers the ability to boost channel capacity and spectral efficiency. However, a massive MIMO system requires huge base station (BS) antennas to handle users and suffers from inter-cell interference that leads to pilot contamination. To cope with this, time-shifted pilots are devised for avoiding interference between cells, by rearranging the order of transmitting pilots in different cells. In this paper, an adaptive-elephant-based spider monkey optimization (adaptive ESMO) mechanism is employed for time-shifted optimal pilot scheduling in a massive MIMO system. Here, user grouping is performed with the sparse fuzzy c-means (Sparse FCM) algorithm, grouping users based on such parameters as large-scale fading factor, SINR, and user distance. Here, the user grouping approach prevents inappropriate grouping of users, thus enabling effective grouping, even under the worst conditions in which the channel operates. Finally, optimal time-shifted scheduling of the pilot is performed using the proposed adaptive ESMO concept designed by incorporating adaptive tuning parameters. The efficiency of the adaptive ESMO approach is evaluated and reveals superior performance with the highest achievable uplink rate of 43.084 bps/Hz, the highest SINR of 132.9 dB, and maximum throughput of 2.633 Mbps

A majority of emerging infectious diseases (EIDs) are zoonotic, mainly caused through spillover events linked to human-animal interactions. We conducted a survey-based human behavioral study in Laikipia County, Kenya, which is characterized by a dynamic human-wildlife-livestock interface. Questionnaires that assessed human-animal interactions, sanitation, and illnesses experienced within the past year were distributed to 327 participants among five communities in Laikipia. This study aimed to 1) describe variation in reported high-risk behaviors by community type and 2) assess the relationship between specific behaviors and self-reported illnesses. Behavioral trends were assessed in R via Fishers exact tests. A generalized linear mixed model with Lasso penalization (GLMMLasso) was used to assess correlations between behaviors and participants self-reported illness within the past year, with reported behaviors as independent variables and reported priority symptoms as the outcome. Reported behaviors varied significantly among the study communities. Participants from one community (Pastoralist-1) were significantly more likely to report eating a sick animal in the past year (p< 0.001), collecting an animal found dead to sell in the past year (p

The study explores how collaborative based exams (CLBE) affect specified learning outcomes in an Accounting Theory course for final year 'accounting major' students. The study proposes Accounting Theory as an avenue to improve the qualitative and problem-solving skills of accounting students and collaborative learning (CL) as a mechanism to enhance students' teamwork skills. The study uses a mixed-methods approach, applying a quantitative method in analysing the relationships and then using focus groups to gain insights about students' reaction to CL and collaborative based exams (CLBE). The results confirm that collaborative based exams (CLBE) after a CL mechanism significantly and comparatively improves students' qualitative and problem-solving based exam scores, reduces pre-exam anxiety and enhances knowledge retention. Both low performing and high CGPA students benefited from CL and collaborative based exams (CLBE). Students, even though appreciative of the visible benefits of CL, contested a group-based grading system, and female students revealed gender biases within group dynamics. This study is the first application of inter and intragroup dependent exam constructs within collaborative based exams (CLBE).

This study identifies significant differences between the learning approaches of mature and 'conventional' students, answering the call for more empirical insights into mature students' learning experiences. The study uses a survey approach, collecting data with the Biggs SPQ Instrument, involving 204 university students in Ghana, and applies various statistical analyses to test for significant differences in mean responses. The results of the study confirm the preference for deep and strategic learning among mature students, but departs from the existing empirical finding, albeit fast-evolving, that conventional students prefer surface learning. It will seem, that the growing relevance of intrinsic motivational reasons for academic pursuit even among conventional students, perhaps due to the reality of non-existing jobs after graduation, has shifted students' motivations with subsequent effects on the approaches to learning. Another reason could be the visible efforts by higher education institutions to improve students' study experience and engage them in developing higher-order cognitive skills. Therefore, even though prior life experiences impact learning approaches, current and future contextual estimations by students also affect their current actions. This is the first application of a dataset from Ghana to the study of learning approaches and also the highest known reliability score for surface approaches using the SPQ instrument.

The study explored the application of closed-book, open-book and cheat-sheet exams in an undergraduate cost and management accounting course at a university in Ghana. 198 students participated in an exploratory study examining how the different exam types impact on exam scores, pre-exam anxiety and knowledge retention. The study improves on the methods used in prior studies by, simplifying the estimation of pre-exam anxiety, and controlling for general student aptitude (GPA) in the specification of model. ANOVA was used to analyse the data. The results of the study provide compelling support for the application of cheat-sheet exams even though the perceptual views of students regarding this exam type were quite low on several variables and parameters.

The objective of the present study is focused on the facile synthesis of ZrO2/La2O3 catalyst and the catalytic performance was evaluated towards one-pot synthesis of tetrahydropyrimidne derivatives through Biginelli condensation reaction. The synthesized catalyst was characterized by using FTIR, XRD, BET, SEM, EDX and UV-DRS techniques. All catalysts perform better than the without catalyst based reactions, which is the formation of tetrahydropyrimidne derivatives (IVa-n) conversion averaging 85–95 % at 50 °C temperature and 3–40 min under identical reaction conditions. Also, it maintains good stability. The relative ease of reducing the catalyst plus its porous nature are responsible for its performance. All the products were characterized by comparing their physical and spectral data including FTIR, 1H NMR, and ESI-MS with those of authentic compounds reported in the literature.

The paper investigated the dynamic and causal relationship among corruption, foreign direct investment, and economic growth simultaneously, a largely overlooked area in empirical studies, using a dataset from Ghana. It is among the few studies that explore the confluence of these variables and therefore contributes to understanding the contextual realities of the impact of FDI inflow, an often-prioritised policy choice, on widely used measures of social coherence and welfare. The study employed a vector autoregressive (VAR) estimation approach to empirically explore the relationships among corruption, foreign direct investment, and economic growth. The findings suggest that there is a reverse causality among corruption, foreign direct investment, and economic growth. This indicates that these variables are complementary rather than contradictory. These findings imply that central government and policymakers should not pursue any of these variables as a policy goal, but rather treat them as complements when modelling or formulating economic policies. This means that policies aimed at promoting foreign direct investment will not jeopardize or compromise the control of corruption and economic growth and vice versa.

Objective: In this study, our objective is to compare the morbidity (up to 3 months) between percutaneous nephrolithotomy (PCNL) and laparoscopic pyelolithotomy (LPL) in patients undergoing surgery for renal pelvic calculus in our population. Materials and Methods: This was a retrospective study done in a urology tertiary care center from January 1, 2016, to December 31, 2018, among patients who had undergone PCNL or LPL for renal pelvic calculus. The sample size was 70, with 35 cases in each group. Results: In LPL arm, there was a significant reduction in the day of the drain or nephrostomy removal (P = 0.013) and in the number of patients with persistent leak after removal of drain or nephrostomy (P = 0.048). Apart from this, the median of postoperative hospital stay was also significantly less in LPL arm (P = 0.00005). However, the mean duration of surgery was significantly higher in the LPL arm (P = 0.00001). Conclusion: This study shows LPL and PCNL morbidity results are almost comparable except in a few factors. However, this study was a retrospective analysis of our work and it needs high quality randomized controlled study to establish the difference among these two procedures among our population.

In this work, graphitic carbon nitride (g-C3N4) was synthesized by directly heating melamine at 550 °C and then a certain amount of Pt and Pd was deposited on it to form g-C3N4/Pt and g-C3N4/Pd nanocomposites used as photocatalysts for the formation of Schiff bases via a mixture of aldehydes (1a-n) (1 mmol) and thiosemicarbazide (1 mmol) and 30 mg of the catalyst under solvent-free conditions at 27 °C in visible light irradiation. The synthesized catalysts were characterized by various techniques. The photocatalytic activity results show as the synthesized g-C3N4/Pd composite demonstrated towards higher activity with superior yield (>95 %) compared to the pristine g-C3N4 nanosheets and/or g-C3N4/Pt composite due to Pd act as an admirable promoter and light absorbing efficiency. With the addition of noble metals (Pt and Pd) to g-C3N4 nanosheets in the composite, photocatalytic response increased significantly which confirms the synergy between the catalytic activity of noble metals and g-C3N4 nanosheets.

Here, we have synthesized CeO2 NPs using Sapodilla fruit (Manilkara zapota) peel (SFP) extract via a green approach. The synthesized SFP extract-CeO2 NPs were characterized by powder XRD, TEM, UV–vis DRS, PL, FTIR, and TGA techniques. CeO2 NPs and SFP extract-CeO2 NPs were confirmed by UV–vis spectra at the strong absorption peak at 400–435 nm and the calculated optical band gaps were well matched. The FT-IR spectra of CeO2 NPs reveal that the presence of carboxyl and amide groups in the SFP extract is confirmed and these are responsible for the bio-reduction of Ce ions into CeO2 NPs. From XRD, the average crystallite size of the SFP extract-CeO2 NPs is 10 ± 1.5 nm was observed, which is a good agreement with TEM analysis. The synthesized CeO2 NPs performed an excellent photodegradation of several dyes and antibiotics in aqueous solutions within 18 min of reaction under UV–visible irradiation. The synthesized SFP extract-CeO2 NPs show good antimicrobial activity against several pathogens (bacteria and fungi) using a paper disc method other than CeO2 NPs. In addition, the antidiabetic activity of SFP extract-CeO2 NPs is significantly inhibited by both α-amylase and α-glucosidase enzymes with IC50 values when compared with the standard (acarbose).

A majority of emerging infectious diseases (EIDs) are zoonotic, mainly caused through spillover events linked to human-animal interactions. We conducted a survey-based human behavioral study in Laikipia County, Kenya, which is characterized by a dynamic human-wildlife-livestock interface. Questionnaires that assessed human-animal interactions, sanitation, and illnesses experienced within the past year were distributed to 327 participants among five communities in Laikipia. This study aimed to 1) describe variation in reported high-risk behaviors by community type and 2) assess the relationship between specific behaviors and self-reported illnesses. Behavioral trends were assessed in R via Fisher's exact tests. A generalized linear mixed model with Lasso penalization (GLMMLasso) was used to assess correlations between behaviors and participants' self-reported illness within the past year, with reported behaviors as independent variables and reported priority symptoms as the outcome. Reported behaviors varied significantly among the study communities. Participants from one community (Pastoralist-1) were significantly more likely to report eating a sick animal in the past year (p< 0.001), collecting an animal found dead to sell in the past year (p

Human yaws has historically been endemic to Kenya, but current epidemiologic data are lacking. We report seroprevalence for Treponema pallidum antibodies in olive baboons (Papio anubis) and vervet monkeys (Chlorocebus pygerythrus) in Laikipia County, Kenya. Our results suggest endemicity of the yaws bacterium in monkeys, posing a possible zoonotic threat to humans.

BackgroundSchistosoma mansoni is one of the most common helminth infections affecting a large population of people in sub-Saharan Africa. This helminth infection is known to cause immunomodulation which has affected the efficacy of a number of vaccines. This study examined whether a chronic schistosoma infection has an effect on the immunogenicity of HPV vaccine which is currently administered to girls and women aged 9 to 24. Little is known about the immune responses of the HPV vaccine in individuals with chronic schistosomiasis.MethodsThis study was carried out at the Institute of Primate Research (IPR) and involved an Olive baboon model. The experimental animals were randomly placed into three groups (n = 3-4); Two groups were infected with S. mansoni cercaria, and allowed to reach chronic stage (week 12 onwards), at week 13 and 14 post-infection, one group was treated with 80mg/kg of praziquantel (PZQ). Sixty four weeks post schistosoma infection, all groups received 2 doses of the Cervarix HPV vaccine a month apart. Specific immune responses to the HPV and parasite specific antigens were evaluated.ResultsAnimals with chronic S. mansoni infection elicited significantly reduced levels of HPV specific IgG antibodies 8 weeks after vaccination compared the PZQ treated and uninfected groups. There was no significant difference in cellular proliferation nor IL-4 and IFN-γ production in all groups.ConclusionChronic S. mansoni infection results in reduction of protective HPV specific IgG antibodies in a Nonhuman Primate model, suggesting a compromised effect of the vaccine. Treatment of schistosomiasis infection with PZQ prior to HPV vaccination, however, reversed this effect supporting anti-helminthic treatment before vaccination.

In April, 2004, chikungunya virus (CHIKV) re-emerged in Kenya and eventually spread to the islands in the Indian Ocean basin, South-East Asia, and the Americas. The virus, which is often associated with high levels of viremia in humans, is mostly transmitted by the urban vector, Aedes aegypti. The expansion of CHIKV presents a public health challenge both locally and internationally. In this study, we investigated the ability of Ae. aegypti mosquitoes from three distinct cities in Kenya; Mombasa (outbreak prone), Kisumu, and Nairobi (no documented outbreak) to transmit CHIKV.Aedes aegypti mosquito populations were exposed to different doses of CHIKV (105.6-7.5 plaque-forming units[PFU]/ml) in an infectious blood meal. Transmission was ascertained by collecting and testing saliva samples from individual mosquitoes at 5, 7, 9, and 14 days post exposure. Infection and dissemination were estimated by testing body and legs, respectively, for individual mosquitoes at selected days post exposure. Tissue culture assays were used to determine the presence of infectious viral particles in the body, leg, and saliva samples. The number of days post exposure had no effect on infection, dissemination, or transmission rates, but these rates increased with an increase in exposure dose in all three populations. Although the rates were highest in Ae. aegypti from Mombasa at titers ≥106.9 PFU/ml, the differences observed were not statistically significant (χ2 ≤ 1.04, DF = 1, P ≥ 0.31). Overall, about 71% of the infected mosquitoes developed a disseminated infection, of which 21% successfully transmitted the virus into a capillary tube, giving an estimated transmission rate of about 10% for mosquitoes that ingested ≥106.9 PFU/ml of CHIKV. All three populations of Ae. aegypti were infectious as early as 5-7 days post exposure. On average, viral dissemination only occurred when body titers were ≥104 PFU/ml in all populations.Populations of Ae. aegypti from Mombasa, Nairobi, and Kisumu were all competent laboratory vectors of CHIKV. Viremia of the infectious blood meal was an important factor in Ae. aegypti susceptibility and transmission of CHIKV. In addition to viremia levels, temperature and feeding behavior of Ae. aegypti may also contribute to the observed disease patterns.

Introduction: Transplantation has been established as a superior mode of renal replacement therapy now. The demand for renal transplantation exceeds the available organs by far and this shortage led to an increase of renal transplantations from living donors. In this context, we did this study to find out perioperative predictors of postoperative short-term morbidity to donor after donor nephrectomy for renal transplantation. Patients and Methods: This was a retrospective study done in a urology tertiary care center from January 1, 2015, to December 31, 2019, among patients who underwent donor nephrectomy for renal transplantation. The sample size was 202. Data were collected using a pro forma and the same were analyzed by appropriate statistical methods using SPSS software. Results: Perioperative factors correlated to paralytic ileus on Pearson's correlation analysis were body mass index and right-sided donor nephrectomy. However, no perioperative factor was found to be predictive of paralytic ileus on regression analysis. Preoperative pyuria and postoperative total white blood cell count were correlated as well as predictive of wound infection. Conclusion: This study shows perioperative predictive factors related to postoperative short-term morbidity to donor and different grades and types of postoperative morbidity among donors after donor nephrectomy in renal transplantation within the first 6 months of surgery. [ABSTRACT FROM AUTHOR]

Massive multiple-input multiple-output (MIMO) is considered to be an emerging technique in wireless communication systems, as it offers the ability to boost channel capacity and spectral efficiency. However, a massive MIMO system requires huge base station (BS) antennas to handle users and suffers from inter-cell interference that leads to pilot contamination. To cope with this, time-shifted pilots are devised for avoiding interference between cells, by rearranging the order of transmitting pilots in different cells. In this paper, an adaptive-elephant-based spider monkey optimization (adaptive ESMO) mechanism is employed for time-shifted optimal pilot scheduling in a massive MIMO system. Here, user grouping is performed with the sparse fuzzy c-means (Sparse FCM) algorithm, grouping users based on such parameters as large-scale fading factor, SINR, and user distance. Here, the user grouping approach prevents inappropriate grouping of users, thus enabling effective grouping, even under the worst conditions in which the channel operates. Finally, optimal time-shifted scheduling of the pilot is performed using the proposed adaptive ESMO concept designed by incorporating adaptive tuning parameters. The efficiency of the adaptive ESMO approach is evaluated and reveals superior performance with the highest achievable uplink rate of 43.084 bps/Hz, the highest SINR of 132.9 dB, and maximum throughput of 2.633 Mbps. [ABSTRACT FROM AUTHOR]

This study explores the innovative integration of machine learning (ML) with wearable sensor technologies for the real-time monitoring of tibial bone force in runners. Utilizing three distinct approaches—a linear regression model based on the Vertical Average Loading Rate (VALR), a physics-based method, and a sophisticated ML algorithm—this research was conducted with 10 participants equipped with wearable sensors. The results revealed the ML model's superior performance over both the physics-based and VALR techniques, achieving Mean Absolute Percentage Errors (MAPEs) of 6.7 percent and 11.3 percent respectively. This was accomplished through extensive training across various datasets. Additionally, the ML approach demonstrated remarkable reliability in 25 different running session simulations, underscoring its effectiveness in complex musculoskeletal analytics. These findings not only highlight the potential of ML in enhancing wearable technology for biomechanical data analysis but also emphasize the necessity for further comprehensive studies in this field.

AbstractThis study explores the nexus among government revenue, government expenditure, and gross domestic product (GDP) across time and/or frequency using a Ghana dataset. It applies the wavelet approaches to investigate the lead-lag nexus, degree of integration and interdependency among public expenditure, public revenue, and gross domestic product (GDP) in the Ghanaian context. The data source is the World Bank and consists of yearly data from 1983 to 2021 yielding 39 observations. While public expenditure and revenue are closely related, and mostly positive throughout both time and frequency, there is a nexus between public spending and revenue at specific intervals and on a regular basis that was bi-directional, bi-causal, and interdependent. Between 1993 and 2021, a bi-directional nexus could be seen; however, most of the arrows pointed to the right. This shows that the co-movements between public spending and revenue are positive and behave similarly as a result. Accordingly, it is anticipated that increased levels of public spending will be met by higher levels of public spending, and vice versa. This is the first application of a wavelet approach to the study of this phenomenon with a Ghana dataset.

AbstractThis study compares the quality of Corporate Social Responsibility (CSR) practices and reporting of firms operating in Africa listed in Western economies and firms exclusively listed on the African stock exchange, using the Global Reporting Initiative (GRI) CSR checklist. Interpretive content analysis was conducted on the website publications and relevant reports of 135 firms listed on African stock exchanges. Non-parametric(Mann-Whitney U and Cohen d test) analyses were applied to check for significant differences between the mean scores of Western-listed firms and locally listed firms operating in African countries. The study’s findings indicate (1) a Low CSR disclosure rate and (2) no significant CSR disclosure difference between exclusively African market-listed firms and multinationals. Multinationals do not lead in sustainability reporting. The finding of this study is a proposal for emerging economies to strengthen institutions and make them independent. The findings further encourage regulators and policymakers to question, with utmost importance, why the sophisticated propitious sustainability initiatives and reporting of Western economies are not practised in the developing world. Unlike previous studies, the current research uses Institutional Theory to compare CSR disclosure tendencies of environmentally Sensitive Industries (ESI) in which environmental policies seemingly make sustainability reporting quasi-mandatory.

Introduction: Transplantation has been established as a superior mode of renal replacement therapy now. The demand for renal transplantation exceeds the available organs by far and this shortage led to an increase of renal transplantations from living donors. In this context, we did this study to find out perioperative predictors of postoperative short-term morbidity to donor after donor nephrectomy for renal transplantation. Patients and Methods: This was a retrospective study done in a urology tertiary care center from January 1, 2015, to December 31, 2019, among patients who underwent donor nephrectomy for renal transplantation. The sample size was 202. Data were collected using a pro forma and the same were analyzed by appropriate statistical methods using SPSS software. Results: Perioperative factors correlated to paralytic ileus on Pearson's correlation analysis were body mass index and right-sided donor nephrectomy. However, no perioperative factor was found to be predictive of paralytic ileus on regression analysis. Preoperative pyuria and postoperative total white blood cell count were correlated as well as predictive of wound infection. Conclusion: This study shows perioperative predictive factors related to postoperative short-term morbidity to donor and different grades and types of postoperative morbidity among donors after donor nephrectomy in renal transplantation within the first 6 months of surgery.

Purpose – This study aimed to explore the effect of Financial Innovation (FI) on economic growth in Ghana, with a dataset spanning 1960–2019, adopting a broader conceptualization of FI as the ratio of broad money to narrow money. Design/methodology/approach – The study employs a non-linear autoregressive distributed lag (ARDL) time series econometric model to estimate data from the World Bank (1960–2019). Findings – There is no evidence that FI significantly impacts economic growth. This could be due to the early and strict regulation of the financial technology (FIN-TECH) sector and the general inconclusiveness of the impact of financial development on economic growth. Practical implications – Policymakers must empirically explore the impact of early and strict regulation on the transformational impact of FI. Originality/value – The paper is among the first to apply a broader conceptualization of FI in estimating the impact of FI on economic growth.

AbstractAs a result of the failure to meet tax collection targets, policymakers, economists, and financiers have focused their attention in recent years on how a country’s tax effort has been employed to combat tax evasion and maximise tax collections for economic growth. The study looked at the nexus between tax efforts, tax evasion, and economic development, as well as the effect of institutional quality on moderating the nexus in Ghana. The maximum likelihood (ML) estimation and structural equation modelling (SEM) techniques were used in the study to analyse a sample of quartered data from 1996 to 2020. Testing the hypotheses reveals that both tax efforts and tax evasion have negative effects on the economic freedom of the world index (EFWI) but positive effects on urbanisation. A test of the third hypothesis shows that institutional quality moderates tax evasion in Ghana in order to influence economic development. The findings imply that the idea that tax evasion is bad for an economy or that tax efforts drive domestic revenue mobilisation is based mainly on prima facie evidence. Tax efforts such as tax amnesty may appear to compliant taxpayers as an incentive for tax evaders, which could affect their compliance. The adoption of the tax efforts index measure to examine its econometric impact on economic development is one of the pioneering attempts in the field. The study recommends well-thought-out strategies to ensure that tax efforts achieve their intended goals.

Most women generally have an ovarian cyst, causing the disorder. Pregnant cysts occur when many water-packed tumors appear in the womb. This is especially true for women who have a worthy cause for childbearing. Women are related to menstrual problems and cyst problems during pregnancy. Recently, ultrasound imaging and machine learning techniques have been used to detect ovarian cysts. Different domain experts provide their own decisions on finding out what kind of ovarian cyst it is from ultrasound images. However, a most accurate and uniform decision-making system is necessary for the early detection of cysts. To aid physicians, an automated detection system has been proposed in this paper to make it more effective for physicians to eliminate these problems. This system uses the extracted features from the image for cysts detection and classification. Automatic ovary cyst detection (OCD) and classification are implemented in this work using a fuzzy rule-based Convolutional Neural Network (FCNN). The proposed system (OCD-FCNN) has yielded 98.37% accurate results when tested with benchmark datasets.

In this paper, we explore Blockchain technology can be used to build a reliable decentralised authentication system. High security for the bioacoustics signal authentication mechanism is guaranteed by using an optimised number of secured features from the bioacoustics signal rather than conventional biometric features for authentication, and by utilising a blockchain model to improve the robustness of multiple checks on the data. It allows for trustworthy authentication and the tracking of terminal activity. Then, light weighted cryptography (LWC) is developed to offer protection at each edge node and terminal. Finally, the belief propagation (BP) algorithm for retraining the features of the bioacoustics signal serves as the foundation for the catching method. It improves hit ratio while decreasing delay time. The experimental setup uses the bioacoustics signals for authentication instead of conventional biometric features, and the use of a blockchain model for data transparency improves the efficiency of multiple checks. When this happens, privacy and safety are both boosted.

Novel 4H chromene coupled triazole hybrids 8a-l were synthesized through a hassle free multicomponent one pot synthesis and click chemistry protocols. The structures of novel compounds were established by interpretation of 1H NMR, 13C NMR, IR and Mass spectral data. The novel hybrids were screened for their invitro antioxidant activity by employing DPPH and Hydrogen peroxide radical scavenging assays, using Ascorbic acid as standard reference. Novel compounds 8h and 8i exhibited superior radical quenching percentage with IC50 value of 1.29 ± 0.35 and 1.23 ± 0.34 µM respectively, compared to the IC50 value of (1.46 ± 0.52 µM) Ascorbic acid. Compounds 8f, 8j and 8k also demonstrated best IC50 value of 3.02 ± 0.62, 2.45 ± 0.53 and 3.18 ± 0.25 µM in comparison to reference. The molecular docking studies of target compounds against the crystal structure of NADPH oxidase endorsed best docking scores and binding interactions, and are in agreement to experimental data.

Background: Zika virus (ZIKV), first described in 1947, is an arthropod-borne virus associated with sporadic outbreaks and interepidemic transmission. Recent studies have implicated nonhuman primates (NHPs) as the probable reservoir hosts. We tested archived serum samples of NHPs collected in Kenya for evidence of neutralizing ZIKV antibodies. Methods: We randomly selected 212 archived serum samples from Institute of Primate Research in Kenya collected between 1992 and 2017. These specimens were tested by microneutralization test. Results: The 212 serum samples were collected in 7 counties from 87 (41.0%) Olive baboons, 69 (32.5%) Vervet monkeys, and 49 (23.1%) Sykes monkeys. Half (50.9%) were male and 56.4% were adult. We detected ZIKV antibodies in 38 (17.9%; 95% confidence interval: 13.3-23.6) samples. Conclusions: These results suggest ZIKV transmission and potential maintenance in nature by NHPs in Kenya.

Background: Schistosoma mansoni is one of the most common helminth infections affecting a large population of people in sub-Saharan Africa. This helminth infection is known to cause immunomodulation which has affected the efficacy of a number of vaccines. This study examined whether a chronic schistosoma infection has an effect on the immunogenicity of HPV vaccine which is currently administered to girls and women aged 9 to 24. Little is known about the immune responses of the HPV vaccine in individuals with chronic schistosomiasis., Methods: This study was carried out at the Institute of Primate Research (IPR) and involved an Olive baboon model. The experimental animals were randomly placed into three groups (n = 3-4); Two groups were infected with S. mansoni cercaria, and allowed to reach chronic stage (week 12 onwards), at week 13 and 14 post-infection, one group was treated with 80mg/kg of praziquantel (PZQ). Sixty four weeks post schistosoma infection, all groups received 2 doses of the Cervarix HPV vaccine a month apart. Specific immune responses to the HPV and parasite specific antigens were evaluated., Results: Animals with chronic S. mansoni infection elicited significantly reduced levels of HPV specific IgG antibodies 8 weeks after vaccination compared the PZQ treated and uninfected groups. There was no significant difference in cellular proliferation nor IL-4 and IFN-γ production in all groups., Conclusion: Chronic S. mansoni infection results in reduction of protective HPV specific IgG antibodies in a Nonhuman Primate model, suggesting a compromised effect of the vaccine. Treatment of schistosomiasis infection with PZQ prior to HPV vaccination, however, reversed this effect supporting anti-helminthic treatment before vaccination., Competing Interests: The authors have declared that no competing interests exist

Background: In April, 2004, chikungunya virus (CHIKV) re-emerged in Kenya and eventually spread to the islands in the Indian Ocean basin, South-East Asia, and the Americas. The virus, which is often associated with high levels of viremia in humans, is mostly transmitted by the urban vector, Aedes aegypti. The expansion of CHIKV presents a public health challenge both locally and internationally. In this study, we investigated the ability of Ae. aegypti mosquitoes from three distinct cities in Kenya; Mombasa (outbreak prone), Kisumu, and Nairobi (no documented outbreak) to transmit CHIKV., Methodology/principal Findings: Aedes aegypti mosquito populations were exposed to different doses of CHIKV (105.6-7.5 plaque-forming units[PFU]/ml) in an infectious blood meal. Transmission was ascertained by collecting and testing saliva samples from individual mosquitoes at 5, 7, 9, and 14 days post exposure. Infection and dissemination were estimated by testing body and legs, respectively, for individual mosquitoes at selected days post exposure. Tissue culture assays were used to determine the presence of infectious viral particles in the body, leg, and saliva samples. The number of days post exposure had no effect on infection, dissemination, or transmission rates, but these rates increased with an increase in exposure dose in all three populations. Although the rates were highest in Ae. aegypti from Mombasa at titers ≥106.9 PFU/ml, the differences observed were not statistically significant (χ2 ≤ 1.04, DF = 1, P ≥ 0.31). Overall, about 71% of the infected mosquitoes developed a disseminated infection, of which 21% successfully transmitted the virus into a capillary tube, giving an estimated transmission rate of about 10% for mosquitoes that ingested ≥106.9 PFU/ml of CHIKV. All three populations of Ae. aegypti were infectious as early as 5-7 days post exposure. On average, viral dissemination only occurred when body titers were ≥104 PFU/ml in all populations., Conclusions/significance: Populations of Ae. aegypti from Mombasa, Nairobi, and Kisumu were all competent laboratory vectors of CHIKV. Viremia of the infectious blood meal was an important factor in Ae. aegypti susceptibility and transmission of CHIKV. In addition to viremia levels, temperature and feeding behavior of Ae. aegypti may also contribute to the observed disease patterns.

Previously, we reported the ability of the chimeric protein DIIIC-2 (domain III of the dengue envelope protein fused to the capsid protein of dengue-2 virus), to induce immunity and protection in mice, when it is highly aggregated with a non-defined oligodeoxynucleotide (ODN) and adjuvanted in alum. In this work, three different defined ODNs were studied as aggregating agents. Our results suggest that the nature of the ODN influences the capacity of protein DIIIC-2 to activate cell-mediated immunity in mice. Consequently, the ODN 39M was selected to perform further experiments in mice and nonhuman primates. Mice receiving the preparation 39M-DIIIC-2 were solidly protected against dengue virus (DENV) challenge. Moreover, monkeys immunized with the same preparation developed neutralizing antibodies, as measured by four different neutralization tests varying the virus strains and the cell lines used. Two of the immunized monkeys were completely protected against challenge, whereas the third animal had a single day of low-titer viremia. This is the first work describing the induction of short-term protection in monkeys by a formulation that is suitable for human use combining a recombinant protein from DENV with alum.

The role of cellular immune response in dengue virus infection is not yet fully understood. Only few studies in murine models propose that CD8(+) T-cells are associated with protection from infection and disease. At the light of recent reports about the protective role of CD8(+) T-cells in humans and the no correlation between neutralizing antibodies and protection observed in several studies, a vaccine based on cell-mediated immunity constitute an attractive approach. Our group has developed a capsid-based vaccine as nucleocpasid-like particles from dengue-2 virus, which induced a protective CD4(+) and CD8(+) cell-mediated immunity in mice, without the contribution of neutralizing antibodies. Herein we evaluated the immunogenicity and protective efficacy of this molecule in monkeys. Neither IgG antibodies against the whole virus nor neutralizing antibodies were elicited after the antigen inoculation. However, animals developed a cell-mediated immunity, measured by gamma interferon secretion and cytotoxic capacity. Although only one out of three vaccinated animals was fully protected against viral challenge, a viral load reduction was observed in this group compared with the placebo one, suggesting that capsid could be the base on an attractive vaccine against dengue., (Copyright © 2014 Elsevier Inc. All rights reserved.)