Comprehensive OPNET based Scalability Analysis and Performance Evaluation of MANET Routing Protocols

A Mobile Ad-hoc Network (MANET) is a collection of communication and computing devices equipped with communication capabilities in which the nodes communicate with each other without any pre-existing infrastructure. Unlike the infrastructure based networks, there are no BTSs and BSCs in MANETs. The nodes involved in the MANETs, therefore, act as both routers and hosts. The nodes involved in the MANETs, therefore, act as both routers and hosts. The network topology varies dynamically and unpredictably due to mobility of the nodes. The conventional IP based routing protocols are not able to handle the unique characteristics of MANETs. Different protocols that can handle the unique characteristics such as dynamic and unpredictably varying topology have therefore been developed. These protocols have different performance and scalability behaviors in different network operation conditions. It is therefore imperative to analyze their scalability and evaluate their performances with respect to the control variables on which MANET networks are mainly optimized and characterized such as the network size, mobility and traffic type and load. In this paper, the scalability and performance behaviors of AODV, DSR and OLSR are analyzed under scalable network size, mobility speed and FTP traffic loads with respect to average end-to-end delay and throughput. OPNET Modeler 14.5 was used as a simulation tool. The results indicated that there is an overall throughput performance increment with increasing network size and FTP traffic load while the delay performance was decreasing. It was also observed that the mobility scaling has not a significant effect on the performance behavior of the protocols. OLSR performs better than the AODV and DSR in terms of delay while AODV performs better than the other two in terms of throughput in all the scenarios considered. Keywords: AODV, Delay, DSR, Throughput, FTP, MANET, OLS

Multimodal analysis of the effects of dexamethasone on high-altitude cerebral oedema : protocol for a pilot study

Background Acute mountain sickness (AMS) is a cluster of symptoms that commonly occur in those ascending to high altitudes. Symptoms can include headaches, nausea, insomnia and fatigue. Exposure to high altitude can also lead to high-altitude cerebral oedema (HACE), which is a potential cause of death whilst mountaineering. Generally, AMS precedes the development of HACE. Historical studies have demonstrated the effectiveness of regular dexamethasone administration in reducing the symptoms of AMS. However, the mechanism by which dexamethasone works to reduce symptoms AMS remains poorly understood. Further studies, simulating altitude using hypoxic tents, have characterised the effect of prolonged exposure to normobaric hypoxia on cerebral oedema and blood flow using MRI. This randomised trial assesses the effect of dexamethasone on hypoxia-induced cerebral oedema in healthy adult volunteers. Methods/design D4H is a double-blind placebo-controlled randomised trial assessing the effect of dexamethasone on hypoxia-induced cerebral oedema. In total, 20 volunteers were randomised in pairs to receive either 8.25 mg dexamethasone or normal saline placebo intravenously after 8 h of hypoxia with an FiO2 of 12%. Serial MRI images of the brain and spinal cord were obtained at hours 0, 7, 11, 22 and 26 of the study along with serum and urinary markers to correlate with the severity of cerebral oedema and the effect of the intervention. Discussion MRI has been used to identify changes in cerebral vasculature in the development of AMS and HACE. Dexamethasone is effective at reducing the symptoms of AMS; however, the mechanism of this effect is unknown. If this study demonstrates a clear objective benefit of dexamethasone in this setting, future studies may be able to demonstrate that dexamethasone is an effective therapy for oedema associated with brain and spinal cord ischaemia beyond AMS

Associations between exclusive breastfeeding duration and children's developmental outcomes: evidence from Siaya county, Kenya

BACKGROUND: Exclusive breastfeeding (EBF) during the first 6 months of life is widely promoted as a key strategy to enhance child health, growth, and development. Even though a high proportion of children in Kenya are currently breastfed exclusively, there is little evidence regarding the developmental benefits during the first year of life. This paper aims to fill this gap by establishing an association between EBF and early childhood developmental outcomes among children below the age of 6 months in Kenya. METHODS: We used data collected as part of a cluster-randomized controlled trial conducted in Bondo sub-county in the western part of Kenya to assess the associations between EBF and development in the first year of life. The primary exposure variable was EBF, and the outcome variable was child development as measured by the Ages and Stages Questionnaire-Third Edition (ASQ-3). RESULTS: We analyzed data from 570 children aged below 6 months at the time of the interview. Breastfeeding children exclusively between 3 and 6 months was associated with 0.61 standard deviation (SD) higher ASQ-3 scores in the adjusted model. When specific domains were considered, in the adjusted models, EBF in the 3-6 months period was associated with 0.44 SD, 0.34 SD and 0.36 SD higher ASQ-3 scores in communication, gross motor, and problem solving domains, respectively. There were weak associations in the fine motor and social-emotional domains. CONCLUSION: EBF in the 3- to 6-month age range has significant positive associations with child development, especially for communication, gross motor, and problem-solving. Programs encouraging mothers to continue EBF in this period may have substantial benefits for children

Natural out-crossing in dwarf pigeonpea

Natural out-crossing rate in pigeonpea was studied at 1CRISAT Center using plant stature (tall plants in dwarf progenies) as the genetic marker. The data indicated natural out-crossing rates of 9.7% to 24.1 % with a pooled value of 13.1% in the six populations studied. These data were comparable to earlier studies at the same site using stem colour and growth habit as genetic markers in tall pigeonpea cultivars thus suggesting that foraging of insect pollination vectors is not influenced by plant type. The implications of natural out-crossing on breeding and maintenance of genetic purity of cultivars is discussed

Benchmarking food environment policies for the prevention of diet-related non-communicable diseases in Kenya: National expert panel’s assessment and priority recommendations

Introduction: Unhealthy food environments drive the increase of diet-related non-communicable diseases (NCDs). Objective: We aimed to examine healthy food environment policies in Kenya and identify priorities for future action. Methods: Using the Healthy Food Environment Policy Index (Food-EPI) we collected evidence on the extent of government action to create healthy food environments across 13 policy and infrastructure support domains and 43 related good practice indicators between 2017 and 2018. A panel of 15 national experts rated the extent of government action on each indicator compared to the policy development cycle and international best practice respectively. Based on gaps found, actions to improve food environments in Kenya were identified and prioritized. Results: In the policy development cycle, 16/43 (37%) of good practice policy indicators were judged to be in ‘implementation’ phase, including: food composition targets, packaged foods’ ingredient lists/nutrient declarations; systems regulating health claims; restrictions on marketing breast milk substitutes; and school nutrition policies. Infrastructure support actions in ‘implementation’ phase included: food-based dietary guidelines; strong political support to reduce NCDs; comprehensive NCD action plan; transparency in developing food policies; and surveys monitoring nutritional status. Half (22/43) of the indicators were judged to be ‘in development’. Compared to international best practice, the Kenyan Government was judged to be performing relatively well (‘medium’ implementation) in one policy (restrictions on marketing breast milk substitutes) and three infrastructure support areas (political leadership; comprehensive implementation plan; and ensuring all food policies are sensitive to nutrition). Implementation for 36 (83.7 %) indicators were rated as ‘low’ or ‘very little’. Taking into account importance and feasibility, seven actions within the areas of leadership, food composition, labelling, promotion, prices and health-in-all-policies were prioritized. Conclusion: This baseline assessment is important in creating awareness to address gaps in food environment policy. Regular monitoring using Food-EPI may contribute to addressing the burden of diet-related NCDs in Kenya

Ocular morbidity and health seeking behaviour in Kwara state, Nigeria: implications for delivery of eye care services.

BACKGROUND: There is currently limited information as to which conditions are most prevalent in communities in developing countries. This makes effective planning of eye services difficult. METHODS: 3,899 eligible individuals were recruited and examined in a cross-sectional survey in Asa Local Government Area, Nigeria. Those who self-reported an ocular morbidity were also asked about their health-seeking behaviour. Health records of local facilities were reviewed to collect information on those presenting with ocular morbidities. RESULTS: 25.2% (95% CI: 22.0-28.6) had an ocular morbidity in at least one eye. Leading causes were presbyopia and conditions affecting the lens and conjunctiva. The odds of having an ocular morbidity increased with age and lower educational attainment. 10.1% (7.7-13.0) self-reported ocular morbidity; 48.6% (40.4-56.8) of them reported seeking treatment. At the facility level, 344 patients presented with an ocular morbidity over one month, the most common conditions were red (26.3%) or itchy (20.8%) eyes. CONCLUSION: Ocular morbidities, including many non vision impairing conditions, were prevalent with a quarter of the population affected. The delivery of eye care services needs to be tailored in order to address this need and ensure delivery in a cost-effective and sustainable manner

Impact of sitagliptin on endometrial mesenchymal stem-like progenitor cells : a randomised, double-blind placebo-controlled feasibility trial

Background: Recurrent pregnancy loss (RPL) is associated with the loss of endometrial mesenchymal stem-like progenitor cells (eMSC). DPP4 inhibitors may increase homing and engraftment of bone marrow-derived cells to sites of tissue injury. Here, we evaluated the effect of the DPP4 inhibitor sitagliptin on eMSC in women with RPL, determined the impact on endometrial decidualization, and assessed the feasibility of a full-scale clinical trial. Methods: A double-blind, randomised, placebo-controlled feasibility trial on women aged 18 to 42 years with a history of 3 or more miscarriages, regular menstrual cycles, and no contraindications to sitagliptin. Thirty-eight subjects were randomised to either 100 mg sitagliptin daily for 3 consecutive cycles or identical placebo capsules. Computer generated, permuted block randomisation was used to allocate treatment packs. Colony forming unit (CFU) assays were used to quantify eMSC in midluteal endometrial biopsies. The primary outcome measure was CFU counts. Secondary outcome measures were endometrial thickness, study acceptability, and first pregnancy outcome within 12 months following the study. Tissue samples were subjected to explorative investigations. Findings: CFU counts following sitagliptin were higher compared to placebo only when adjusted for baseline CFU counts and age (RR: 1.52, 95% CI: 1.32–1.75, P<0.01). The change in CFU count was 1.68 in the sitagliptin group and 1.08 in the placebo group. Trial recruitment, acceptability, and drug compliance were high. There were no serious adverse events. Explorative investigations showed that sitagliptin inhibits the expression of DIO2, a marker gene of senescent decidual cells. Interpretation: Sitagliptin increases eMSCs and decreases decidual senescence. A large-scale clinical trial evaluating the impact of preconception sitagliptin treatment on pregnancy outcome in RPL is feasible and warranted. Funding: Tommy's Baby Charity. Clinical trial registration: EU Clinical Trials Register no. 2016-001120-54

Effect of dietary potassium restriction on serum potassium, disease progression, and mortality in chronic kidney disease : a systematic review and meta-analysis

Low-potassium diets are recommended to reduce serum potassium (Sk) and prevent complications of chronic kidney disease (CKD), but evidence underpinning this recommendation has not been systematically reviewed and synthesized. We conducted a systematic review comparing change in Sk, CKD progression, and mortality between those on a low-potassium versus unrestricted potassium diet. We searched Medline, AMED, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, and Clinicaltrials.org from inception to 3 April 2018. We included randomized and observational studies that compared these outcomes in adults with CKD who ate a restricted versus unrestricted amount of dietary potassium. We pooled mean change in Sk and adjusted hazard ratios of disease progression and mortality using random-effects meta-analyses. We identified 5,563 articles, of which seven studies (3,489 participants) met our inclusion criteria. We found very low-quality evidence that restricted (1,295 mg/d) versus unrestricted (1,570 mg/d) dietary potassium lowered Sk by -0.22 mEq/L (95% confidence interval [CI]: -0.33, -0.10; I  = 0%). Lower (1,725 mg/d) versus higher (4,558 mg/d) dietary potassium was not significantly associated with disease progression (hazard ratio [HR]: 1.14; 95% CI: 0.77, 1.70; I  = 57%). Lower (1,670 mg/d), compared with higher (4,414 mg/d) dietary potassium intake was associated with a 40% reduction in mortality hazard (HR: 0.60; 95% CI: 0.40, 0.89; I  = 56%). Very-low-quality evidence supports consensus that dietary potassium restriction reduces Sk in normokalemia and is associated with a reduced risk of death in those with CKD. High-quality randomized controlled trials are needed. [Abstract copyright: Copyright © 2019 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Modelling nitrogen mineralization from manures: representing quality aspects by varying C:N ratio of sub-pools

The mineralization/immobilization of nitrogen when organic sources are added to soil is represented in many simulation models as the outcome of decomposition of the added material and synthesis of soil organic matter. These models are able to capture the pattern of N release that is attributable to the N concentration of plant materials, or more generally the C:N ratio of the organic input. However, the models are unable to simulate the more complex pattern of N release that has been observed for some animal manures, notably materials that exhibit initial immobilization of N even when the C:N of the material suggests it should mineralize N. The APSIM SoilN module was modified so that the three pools that constitute added organic matter could be specified in terms of both the fraction of carbon in each pool and also their C:N ratios (previously it has been assumed that all pools have the same C:N ratio). It is shown that the revised model is better able to simulate the general patterns on N mineralized that has been reported for various organic sources. By associating the model parameters with measured properties (the pool that decomposes most rapidly equates with water-soluble C and N; the pool that decomposes slowest equates with lignin-C) the model performed better than the unmodified model in simulating the N mineralization from a range of feeds and faecal materials measured in an incubation experimen

The relationship between obstructive sleep apnoea and quality of life in women with polycystic ovary syndrome: a cross-sectional study

Background: Obstructive sleep apnoea (OSA) and polycystic ovary syndrome (PCOS) are associated with significant comorbidities and commonly coexist. The primary aim of this study was to examine the relationship between OSA and quality of life (QoL) in women with PCOS. Methods: We conducted an observational cross-sectional study. PCOS was diagnosed according to the Rotterdam criteria. Women with increased risk of OSA, based on the Berlin questionnaire or the Epworth Sleepiness Scale (ESS), had home-based polysomnography performed (ALICE PDx). Participants were divided into two groups: (a) PCOS only: women with normal ESS and low-risk Berlin questionnaire (no sleep studies performed), or women with normal sleep studies [oxygen desaturation index (ODI) < 5 events/hour]; and (b) PCOS+OSA: women with PCOS and OSA ODI ⩾ 5. QoL was assessed using the World Health Organization QoL questionnaire (WHOQOL-BREF) and the PCOS health-related quality of life questionnaire (PCOSQ). Results: A total of 39 women were included; age (mean ± SD) was 32.2 ± 8.9 years, weight 92.5 ± 23.7 kg and body mass index (BMI) 34.1 ± 7.9 kg/m 2; 38.5% (n = 15) had OSA. Compared with women with PCOS only, women with PCOS+OSA had higher BMI, HbA1c, C-reactive protein and low-density lipoprotein. ODI was independently associated with impaired QoL. Excessive daytime sleepiness (EDS) was independently associated with anxiety, depression and impaired QoL. Conclusions: OSA is highly prevalent and is associated with impaired QoL and worse metabolic profile in women with PCOS. Interventional studies are needed to examine the impact of OSA in women with PCOS. ClinicalTrials.gov Identifier: NCT03065322