Modeling of free radical polymerization up to high conversion. I. A method for the selection of models by simultaneous parameter estimation

A systematic quantitative method for the selection of models for the high-conversion free radical polymerization exhibiting gel and glass effects has been developed. Four representative models were selected from the literature and were compared on the basis of the same experimental data. All models describe the isothermal time-conversion data over the entire conversion range for a single type and loading of initiator well. Models that are not considering the effect of molecular weight of the polymers on the diffusion of macro radicals fail to describe the time-conversion data if the concentration of the initiator varies at the same time. By simultaneous fitting of the conversion and polymerization degree data it was shown that the Marten-Hamielec model and its extended form (Panke-Stickler-Hamielec model) were not able to describe the number average polymerization degree Pn at the final conversion, where the glass effect occurs. This occurred because both models neglect the change of the radical efficiency f in this region, which has more effect on Pn than the change of the propagation rate coefficient (see part II of this series)

Field evaluation of rK39 test and direct agglutination test for diagnosis of visceral leishmaniasis in a population with high prevalence of human immunodeficiency virus in Ethiopia

Accuracy of an rK39 rapid diagnostic test (DiaMed-IT-Leish ) for visceral leishmaniasis (VL) was compared with splenic aspiration and the direct agglutination test (DAT) in a population with a high prevalence of infection with human immunodeficiency virus (HIV) in Ethiopia. There were 699 patients clinically suspected of having VL (153 parasitologically confirmed, 482 DAT confirmed, and 130 DAT negative), and 97 DAT-negative controls. A total of 84% were tested for HIV and 34% were HIV positive. Sensitivity of the rK39 test in parasitologically confirmed VL patients was 84% (77% in HIV positive and 87% in HIV negative; P = 0.25). Sensitivity of the DAT was higher (94%; P = 0.01), 89% in HIV-positive patients and 95% in HIV-negative patients; P = 0.27). Specificity of the rK39 test was 99% in DAT-negative controls and 92% in DAT-negative patients clinically suspected of having VL. A diagnostic algorithm combining DAT and the rK39 test had a sensitivity of 98% in HIV-positive VL patients and 99% in HIV-negative VL patients. Despite the lower sensitivity in a population with a high prevalence of HIV, the DiaMed-IT-Leish rK39 test enables decentralization of diagnosis. Patients clinically suspected of having VL who show negative results on the rK39 antigen test should undergo follow-up DAT testing, especially if they are HIV positive

Abdominal Surgical Emergencies at Tikur Anbessa Specialized Hospital in Ethiopia; A Shifting Paradigm

Background: Developing nations in Africa may be experiencing changing demographics for abdominal surgical emergencies. In the past, intestinal obstruction has been the major diagnosis, but this may be changing.123 This study analyzed the causes and outcomes for abdominal surgicalemergencies (ASE) in Tikur Anbessa Specialty Hospital (TASH) in Addis Ababa, Ethiopia.Methods: TASH is a tertiary medical center and teaching hospital. This is retrospective study included patients treated for ASE from July 1, 2010 to June 30, 2012. Information was collected in de-identified manner for analysis from the operating room logbook and from chart review. We analyzed demographics, clinical presentation and outcomes of emergency surgery in these patents using SAS 9.2 software. Univariant analysis was performed. P value < 0.05 was considered significant.Results: A total of 530 patients presented with ASE, representing 18.6% of all surgical emergencies. Of these, 328 charts were available for review. 237 (72.3%) were males and the mean age was 36 years. Appendicitis (simple and complicated combined) were the most common cause of ASE accounting for 92 (28.0%). Bowel obstruction and penetrating trauma were present in 17% and 13% of the time respectively. The Overall Morbidity and mortality rates were 30% and 18% respectively. Wound infection andPneumonia were the two most common post operative complications  accounting for 25% and 12% respectively. A total of 61 patients (18.6%) died following ASE. Septic complications accounted for over 50% of the death. Mortality was significantly higher in patients with age >60 years (p<0.0001) and in those who developed post operative complications. (p< 0.0001)Conclusion: The causes for ASE at TASH in Ethiopia have changed with appendicitis being the most common. This study shows a higher morbidity and mortality rates when compared to previous reports. Further study is required to understand better specific interventions needed to reduce thishigh mortality due to sepsis

Responses of tropical maize landraces to damage by Chilo partellus stem borer

The potential to manage insect pests using host-plant resistance exists, but has not been exploited adequately. The objective of this study was to determine the resistance of 75 tropical maize landraces through artificial infestation with Chilo partellus Swinhoe. The trial was laid in alpha-lattice design and each seedling was infested with five neonates three weeks after planting, over two seasons in 2009 and 2010. The number of exit holes, tunnel length, ear diameter, ear length, plant height, stem diameter, stem lodging and grain yield were measured and a selection index computed. GUAT 1050 was the most resistant with an index of 0.56, while BRAZ 2179 was the most susceptible with an index of 1.66. Ear characteristics were negatively correlated with damage parameters. The principal component biplot suggested that exit holes, cumulative tunnel length, leaf damage, cob diameter, stem lodging, selection index, ear and plant height contributed 71.2% of the variation in resistance. The mean number of exit holes and tunnel length for resistant landraces and resistant hybrid checks were similar; at 5.5 and 2.48 cm, respectively. The identified resistant landraces (GUAT 1050, GUAT 280, GUAT 1093, GUAT 1082, GUAT 1014, CHIS 114, and GUAN 34) could be used to develop C. partellus stem borer-resistant maize genotypes.Key words: Chilo partellus, ear length, exit holes, stem borer resistance, tunnel length

A Guide to Biological Control of Fall Armyworm in Africa Using Egg Parasitoids

Fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), a voracious agricultural pest native to North and South America, was first detected on the African continent in 2016 and has subsequently spread throughout the continent and across Asia. Fall armyworm (FAW) is known to feed on over 350 plant species and it has been predicted to cause up to $US 13 billion per annum in crop losses throughout sub-Saharan Africa, thereby threatening the livelihoods of millions of poor farmers. Since the occurrence of FAW in Africa, synthetic chemical insecticides have been widely used as emergency responses to halt distribution of the pest and minimize damage in maize fields. Most smallholder farmers in Africa and Asia, however, cannot afford frequent insecticide applications. Furthermore, dependence on chemical insecticides results in the development of resistance to major classes of insecticides, effects on nontarget organisms, as well as other adverse effects to humans and the environment. This highlights the need for the development of integrated pest management (IPM) strategies that are suitable to African smallholder farmers. Biological control using egg parasitoids particularly from the genus Trichogramma and Telenomus remus is part of the IPM approach presently underway to control FAW in North and South America. The approach involves mass rearing and release of these egg parasitoids to control FAW. These egg parasitoids are reared on factitious and natural hosts. Various species of both parasitoids are already present in Africa. After identifying the species/strain that best suit the local condition, the parasitoid wasps can be mass reared and used against FAW and other lepidopteran pests. Therefore, the purpose of this book is to provide guidelines on mass rearing systems for both the egg parasitoids and their hosts. The book describes the methods used to mass produce FAW (S. frugiperda), rice meal moth (Corcyra cephalonica (Stainton), Lepidoptera: Pyralidae), egg parasitoids - (Trichogramma chilonis Ishii, Hymenoptera: Trichogrammatidae) and (Telenomus remus Nixon, Hymenoptera: Platygastridae) in the facilities at icipe- Kenya and ICRISAT-Niger. This guide is primarily intended for biological control practitioners at universities, research institutes and commercial laboratories particularly involved in managing FAW and other lepidopteran pests. The information in this document is also intended to assist those who are relatively new at rearing FAW, rice meal moth, and the parasitoid wasps and to those who wish to improve existing rearing systems. The document covers virtually all aspects of information on the rearing techniques of each species such as colony establishment, stock culture maintenance, diet preparation, mass rearing, storage, quality control and field release. Each section is interrelated, contains step-by-step procedures, and is supported by colour pictures. The guide produced jointly by the International Centre of Insect Physiology and Ecology (icipe), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Haramaya University, and Virginia Tech through support provided by the Feed the Future Innovation Lab for Integrated Pest Management, funded by the of the US Agency for International Development (USAID) under the Cooperative Agreement No. AID-OAA-L-15-00001. International Centre of Insect Physiology and Ecology (icipe) is an international scientific research institute, headquartered in Nairobi, Kenya that works towards improving lives and livelihoods of people in Africa. The center’s main objective is to research and develop alternative and environmentally friendly pest and vector management strategies that are effective, selective, non-polluting, non-resistance inducing, and which are affordable to resource-limited rural and urban communities. icipe's mandate extends to the conservation and use of the rich insect biodiversity found in Africa. Today, icipe is the only international center in sub-Saharan Africa working primarily on arthropods. icipe focuses on sustainable development using human health as the basis and the environment as the foundation for sustainability (http://www.icipe.org/). International Crops Research Institute for the Semi-Arid Tropics (ICRISAT): is a non-profit, non-political organization that conducts agricultural research for development in the drylands of Asia and sub-Saharan Africa. Covering 6.5 million square kilometers of land in 55 countries, the semi-arid or dryland tropics has over 2 billion people, and 644 million of these are the poorest of the poor. ICRISAT and its partners help empower these poor people to overcome poverty, hunger and a degraded environment through better agriculture. ICRISAT is headquartered in Hyderabad, Telangana State, in India, with two regional hubs (Nairobi, Kenya and Bamako, Mali) and country offices in Niger, Nigeria, Zimbabwe, Malawi, Ethiopia and Mozambique. ICRISAT is a member of the CGIAR system Organization (https://www.icrisat.org/). Virginia Polytechnic Institute and State University, commonly known as Virginia Tech, is a public, land-grant research university with its main campus in Blacksburg, Virginia (https://vt.edu/). The university houses the Feed the Future Innovation Lab for Integrated Pest Management, which aims to improve the livelihoods of smallholder farmers by implementing sustainable crop solutions in the developing world. Haramaya University is a public academic and research university with its main campus in Haramaya, located at about 510 km East of Addis Ababa, Ethiopia. The university offers 264 academic programs of which 113 are undergraduate programs, 131 are second degree (M.Sc./M.Ed./MPH) and 20 are PhD level training programs. In addition, the university has been actively involved in research activities, primarily in the fields of agriculture

Cardiorenal Biomarkers, Canagliflozin, and Outcomes in Diabetic Kidney Disease: The CREDENCE Trial

BACKGROUND: People with type 2 diabetes and albuminuria are at an elevated risk for cardiac and renal events. The optimal biomarkers to aid disease prediction and to understand the benefits of sodium-glucose cotransporter-2 inhibition remain unclear. METHODS: Among 2627 study participants in the CREDENCE trial (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation), concentrations of NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity cardiac troponin T, growth differentiation factor-15, and IGFBP7 (insulin-like growth factor binding protein 7) were measured. The effect of canagliflozin on biomarker concentrations was evaluated. The prognostic potential of each biomarker on the primary outcome (a composite of end-stage kidney disease [dialysis, transplantation, or a sustained estimated glomerular filtration rate of <15 mL·min-1·1.73 m-2], doubling of the serum creatinine level, or renal death or cardiovascular death) was assessed. RESULTS: The median (quartiles 1 and 3) concentration of each biomarker was generally elevated: NT-proBNP, 180 ng/L (82, 442 ng/L); high-sensitivity cardiac troponin T, 19 ng/L (12, 29 ng/L); growth differentiation factor-15, 2595 ng/L (1852, 3775 ng/L); and IGFBP7, 121.8 ng/mL (105.4, 141.5 ng/mL). At 1 year, the biomarkers all rose by 6% to 29% in the placebo arm but only by 3% to 10% in the canagliflozin arm (all P<0.01 in multivariable linear mixed-effect models). Baseline concentrations of each biomarker were strongly predictive of cardiac and renal outcomes. When the biomarkers were analyzed together in a multimarker panel, individuals with high risk scores (hazard ratio [HR], 4.01 [95% CI, 2.52-6.35]) and moderate risk scores (HR, 2.39 [95% CI, 1.48-3.87]) showed a higher risk for the primary outcome compared with those with low risk scores. By 1 year, a 50% increase in NT-proBNP (HR, 1.11 [95% CI, 1.08-1.15]), high-sensitivity cardiac troponin T (HR, 1.86 [95% CI, 1.64-2.10]), growth differentiation factor-15 (HR, 1.45 [95% CI, 1.24-1.70]), and IGFBP7 (HR, 3.76 [95% CI, 2.54-5.56]) was associated with risk of the primary outcome. CONCLUSIONS: Multiple cardiorenal stress biomarkers are strongly prognostic in people with type 2 diabetes and albuminuria. Canagliflozin modestly reduced the longitudinal trajectory of rise in each biomarker. Change in the biomarker level in addition to the baseline level augments the primary outcome prediction. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02065791

People who once had 40 cattle are left only with fences: Coping with persistent drought in Awash, Ethiopia

How to support those responding to environmental change in resource-constrained environments is central to literature on climate change adaption. Our research explores a gap in this literature relating to the negotiation of intra-household relations and resource access across different types of household in contexts of social and environmental transition. Using the example of the semi-arid Awash region in North-Eastern Ethiopia, which has experienced drought and alien plant invasion over the past decade, we explore how men and women use changes in household structures and relationships to adapt more effectively. We draw evidence from life histories with 35 pastoralists across three rural, peri-urban and urban communities. Using Dorward et al’s taxonomy, we find Afar people are not only ‘stepping up’, but also ‘stepping out’: shifting from pastoralism into agriculture and salaried employment. As this often involves splitting households across multiple locations, we look at how these reconfigured households support pastoralists’ wellbeing