Strategic Delegation by Unobservable Incentive Contracts.

STRATEGIC DELEGATION; UNOBSERVABLE CONTRACTS; FORWARD INDUCTION.

Hygienic and sanitary practices of vendors of street foods in Nairobi, Kenya

The street food industry has an important role in the cities and towns of many developing countries in meeting the food demands of the urban dwellers. It feeds millions of people daily with a wide variety of foods that are relatively cheap and easily accessible. Street food sector symbolizes the street life in Africa and it operates in an unstable and precarious state because the sector  lacks legal recognition. There have been noticeable increases of food vendors in Nairobi, who sell both raw and cooked food  items. There are not regulated, they operate  haphazardly without any monitoring of what they prepare and how they do it. A study to determine hygienic and sanitary practices of vendors of street foods in Nairobi was carried out using a descriptive survey  design. A sample size of 80 street food vendors selling commonly consumed foods was selected. Data was collected using  in-depth interview schedules and observation checklists. Information from the study shows that vendors lacked training on food preparation. About 62% obtained food preparation skills through observation while 33% were taught by their parents in  non-formal settings. The preparation surfaces used for the preparation of raw foods were not washed regularly. Cooked foods were stored at ambient temperature in cupboards, plastic bowls, jugs and buckets were just left in the open uncovered. Eighty-five per cent of the vendors had garbage and waste bins beside the food stalls. Personal hygiene was not also observed, as the vendors  never covered their heads, handled money and food at the same time and they did not wear overcoats/aprons and handled food with bare hand. Street food vendors were not aware of hygienic and sanitary practice. The food is sold to unsuspecting clients who are likely to get food-borne diseases. This study recommends the establishment of street food centres by the city council, the training of street food vendors on hygiene, sanitation and the establishment of code of practice for the street food industry and the empowerment of Public Health Officers.Key words. Street foods, hygiene and sanitation

Tunable Functionality and toxicity studies of Titanium Dioxide Nanotube Layers

In this work, we have developed economic process to elaborate scalable titanium dioxide nanotube layers which show a tunable functionality. The titanium dioxide nanotube layers was prepared by electrochemical anodization of Ti foil in 0.4 wt% hydrofluoric acid solution. The nanotube layers structure and morphology were characterized using x-ray diffraction and scanning electron microscopy. The surface topography and wettability was studied according to the anodization time. The sample synthesized while the current density reached a local minimum displayed higher contact angle. Beyond this point, the contact angles decrease with the anodization time. Photo-degradation of acid orange 7 in aqueous solution was used as a probe to assess the photo-catalytic activity of titanium dioxide nanotube layers under UV irradiation. We obtained better photocatalitic activity for the sample elaborate at higher current density. Finally we use the Ciliated Protozoan T. pyriformis, an alternative cell model used for in vitro toxicity studies, to predict the toxicity of titanium dioxide nanotube layers in biological system. We did not observe any characteristic effect in the presence of the titanium dioxide nanotube layers on two physiological parameters related to this organism, non-specific esterases activity and population growth rate

Segmentation par logique floue pour l’estimation du nombre de globules rouges dans des images multi-spectrales de frottis sanguin non marqué

Dans ce travail, nous avons étudié l’introduction de la logique floue dans les processus de segmentation d’images multi-spectrales de frottis sanguin. Notre approche s’appuie sur l’utilisation de l’analyse en composante principale (ACP) sur le jeu d’images spectrales, suivi de l’utilisation de la logique floue sur la première composante principale des images, comme méthode de segmentation des globules rouges. Elle nous a permis de définir une appartenance graduelle des globules rouges à une classe, facilitant ainsi leur comptage. Le résultat donne lieu à 1.53% d’erreur par rapport au comptage manuel, et nous montre que cette technique permet d’atteindre des résultats proches de ceux des méthodes standards, quant à l’estimation du nombre de globules rouges dans l’image d’un frottis sanguin.Mots-clés: logique floue, segmentation, images multi-spectrales, parasitemie, analyse en composante principale. Segmentation by fuzzy logic to estimate the number of red blood cells in multi-spectral images of unstained blood smearIn this work, we studied the inclusion of fuzzy logic in the segmentation process of multispectral images of blood smear. Our approach is based on the use of principal component analysis (PCA), followed by the application of fuzzy logic to the first principal component images as segmentation method of red blood cells. It allowed us to define a gradual membership of red blood cells to a class, thus facilitating their counting. The results give rise to 1.53% of error compared to manual counting; this shows that this technique can provide a reliable data information about the estimated number of red blood cells in the image of an unstained blood smears.Keywords: fuzzy logic, image segmentation, multi-spectral images, parasitemia, principal component analysis

Aplicación de EOMs y arcillas naturales para la eliminación de MCPD y EG de aceites comestibles

The aim of this study was to investigate the removal of 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters (GEs) from edible oils by using Metal Organic Frameworks (MOF) and natural clays. First, the model oil was treated with adsorbents and titanium (IV) butoxide-terephthalate MOF (Ti-MOF) and kaolin were selected as the best performing MOF along with natural clay, respectively, for the removal of 3-MCPD and GEs. The effects of treatment conditions were also investigated, 6.0% adsorbent level, 120 min treatment time and 95 ºC temperature were determined to be the best treatment parameters. Finally, palm oil samples were treated with Ti-MOF and kaolin under the selected conditions and removal of 3-MCPD and GEs was obtained at up to 27% and 58%, respectively. In conclusion, MOFs and natural clays showed good potential for the removal of 3-MCPD and GEs, and the efficiency of the treatment can be improved by modifying the adsorbents.El objetivo de este estudio fue investigar la eliminación de 3-monocloropropano-1,2-diol (3-MCPD) y ésteres de glicidilo (EG) de aceites comestibles mediante el uso de estructuras orgánicas metálicas (EOMs) y arcillas naturales. El aceite modelo se trató en primer lugar con adsorbentes, se seleccionaron titanium (IV) tereftalato de butóxido (Ti-EOM) y caolín como EOM y arcilla natural, respectivamente, para el mejor rendimiento en la eliminación de 3-MCPD y EG. También se investigaron los efectos de las condiciones de tratamiento y se seleccionaron como los mejores parámetros un nivel de adsorbente de 6,0%, un tiempo de tratamiento de 120 min y temperatura de tratamiento de 95ºC. Finalmente, las muestras de aceite de palma se trataron con Ti-EOM y caolín en las condiciones seleccionadas y se obtuvo una eliminación de 3-MCPD y EG de hasta 27% y 58%, respectivamente. En conclusión, los EOMs y las arcillas naturales mostraron un buen potencial para la eliminación de 3-MCPD y EG, y la eficiencia del tratamiento se puede mejorar modificando los adsorbentes

Aceite de semilla de cardo mariano prensado en frío: propiedades físico-químicas, composición y análisis sensorial

Cold pressed oil was produced from milk thistle seeds, and its composition and sensorial properties were determined. The seeds were found to contain 14.98% oil, 17.31% protein and 4.14% ash. The peroxide value of the oil (11.39 meqO2/kg oil) was within acceptable limits according to codex, but the free fatty acidity value (3.45%) exceeded the limit. The oil melted at -20.18 °C and crystallized at -3.71 °C. Linoleic acid (51.97%), β-sitosterol (67.56 mg/100 g oil) and γ-tocopherol (53.60 mg/kg oil) were determined as the main components, respectively. Six sensory descriptive terms (sweet, spicy, raw vegetable, straw, roasted and throat-catching) were described for the oil. Consumer tests proved that cold-pressed milk thistle seed oil had intermediate acceptance scores and consumer satisfaction was moderate. In conclusion, it is thought that milk thistle seeds could be used for the production of edible gourmet oil. Further studies regarding the composition of the bio-active molecules in the oil are anticipated.Se obtuvo aceite prensado en frío a partir de semillas de cardo mariano y se determinó su composición y propiedades sensoriales. Se encontró que las semillas contenían 14,98% de aceite, 17,31% de proteína y 4,14% de ceniza. El índice de peróxido del aceite (11,39 meqO2/kg de aceite) se encontraba dentro del límite aceptable según el Codex, pero el índice de acidez libre (3,45 %) excedía el límite. El aceite fundió a -20,18°C y cristalizó a -3,71°C. Se determinaron como componentes principales el ácido linoleico (51,97%), β-sitosterol (67,56 mg/100 g de aceite) y γ-tocoferol (53,60 mg/kg de aceite), respectivamente. Se describieron en el aceite seis términos descriptivos sensoriales: dulce, picante, vegetal crudo, pajizo, asado y pegajoso. Las pruebas de consumo demostraron que el aceite de semilla de cardo mariano prensado en frío tenía puntuaciones de aceptación intermedias y la satisfacción del consumidor era moderada. En conclusión, se cree que las semillas de cardo mariano podrían utilizarse para la producción de aceite gourmet comestible. Se requieren más estudios sobre la composición de moléculas bioactivas del aceite

Working School Children in a Nigerian Community: Revisiting the Issues

Purpose: The prevalence, risk factors and effects of work on school performance and health consequences of child labour among school children in a rapidly urbanising community in south west Nigeria was assessed. Methods: A descriptive cross-sectional study of 386 Junior Secondary School students was conducted. Questionnaires were used to obtain information on the students’ socio-demographic characteristics, history of child labour activities, and recent history of illness. The academic records of the students were also reviewed. Results: The prevalence of child labour was 72.5%, the median number of hours spent working per week was 18 hours (range 2- 56 hours). The main reason for working was to augment the family income (37.6%). Child labour was commoner among those: whose mothers were not educated; who had four to eight siblings, and who had a working sibling. Higher proportions of working children had repeated a class and had failed the previous term’s examinations. More of the working children reported being ill and injured in the previous term. Conclusion: Child labour is quite common in this area and is associated with negative academic and health outcomes. Multidisciplinary programmes targeted at reducing the practice should be developed.Keywords: Child labour, secondary school students, south west Nigeri

Caracterización integral de las propiedades fisicoquímicas, térmicas, composicionales y sensoriales del aceite de semilla de rosa mosqueta prensado en frío

In this study, cold-pressed rosehip seed oil was fully characterized. Acidity and oxidation levels were near the limit values or slightly exceeded them and improvement in the storage conditions was suggested. The oil started to crystallize at -45.25 °C, and melt at -25.56 °C. Linoleic acid (51.1%), β-sitosterol (84.6%), γ-tocopherol (773.76 µg/g) and rosmarinic acid (31.38 µg/g) were determined as major fatty acid, sterol, tocopherol and phenolic compound, respectively. For the first time, aromatic volatile compounds and sensory descriptive terms were determined for cold-pressed rosehip seed oil. Sixty-seven volatile compounds were detected and L-limonene was found to be a major volatile compound. According to the sensory analysis, timber/kindling and raw vegetable tastes/aromas were found to be relatively dominant. Consequently, it is thought that rosehip seeds can be used as a raw material for edible and nutritionally-rich cold-pressed oil production and/or as source oil for functional food preparations.En este estudio se caracterizó completamente el aceite de semilla de rosa mosqueta prensado en frío. Los niveles de acidez y oxidación estaban cerca de los valores límite o los excedían ligeramente y se sugirió mejorar las condiciones de almacenamiento. El aceite comenzó a cristalizar a -45,25°C y a fundirse a -25,56°C. Se determinó el ácido linoleico (51,1%), β-sitosterol (84,6%), γ-tocoferol (773,76 µg/g) y ácido rosmarínico (31,38 µg/g) como principal ácido graso, esterol, tocoferol y compuesto fenólico, respectivamente. Por primera vez, se determinaron compuestos aromáticos volátiles y términos descriptivos sensoriales para el aceite de semilla de rosa mosqueta prensado en frío. Se detectaron sesenta y siete compuestos volátiles y se descubrió que el L-limoneno era un compuesto volátil importante. Según el análisis sensorial, se encontró que los sabores/aromas de madera/astillas y vegetales crudos eran relativamente dominantes. En consecuencia, se cree que las semillas de rosa mosqueta pueden usarse como materia prima para la producción de aceite prensado en frío comestible y nutritivo y/o como aceite fuente para preparaciones de alimentos funcionales

A critical review on sustainable biochar system through gasification: energy and environmental applications

This review lays great emphasis on production and characteristics of biochar through gasification. Specifically, the physicochemical properties and yield of biochar through the diverse gasification conditions associated with various types of biomass were extensively evaluated. In addition, potential application scenarios of biochar through gasification were explored and their environmental implications were discussed. To qualitatively evaluate biochar sustainability through the gasification process, all gasification products (i.e., syngas and biochar) were evaluated via life cycle assessment (LCA). A concept of balancing syngas and biochar production for an economically and environmentally feasible gasification system was proposed and relevant challenges and solutions were suggested in this review

Formulating and managing viable SLAs in cloud computing from a small to medium service provider's viewpoint: A state-of-the-art review

© 2017 Elsevier Ltd In today's competitive world, service providers need to be customer-focused and proactive in their marketing strategies to create consumer awareness of their services. Cloud computing provides an open and ubiquitous computing feature in which a large random number of consumers can interact with providers and request services. In such an environment, there is a need for intelligent and efficient methods that increase confidence in the successful achievement of business requirements. One such method is the Service Level Agreement (SLA), which is comprised of service objectives, business terms, service relations, obligations and the possible action to be taken in the case of SLA violation. Most of the emphasis in the literature has, until now, been on the formation of meaningful SLAs by service consumers, through which their requirements will be met. However, in an increasingly competitive market based on the cloud environment, service providers too need a framework that will form a viable SLA, predict possible SLA violations before they occur, and generate early warning alarms that flag a potential lack of resources. This is because when a provider and a consumer commit to an SLA, the service provider is bound to reserve the agreed amount of resources for the entire period of that agreement – whether the consumer uses them or not. It is therefore very important for cloud providers to accurately predict the likely resource usage for a particular consumer and to formulate an appropriate SLA before finalizing an agreement. This problem is more important for a small to medium cloud service provider which has limited resources that must be utilized in the best possible way to generate maximum revenue. A viable SLA in cloud computing is one that intelligently helps the service provider to determine the amount of resources to offer to a requesting consumer, and there are number of studies on SLA management in the literature. The aim of this paper is two-fold. First, it presents a comprehensive overview of existing state-of-the-art SLA management approaches in cloud computing, and their features and shortcomings in creating viable SLAs from the service provider's viewpoint. From a thorough analysis, we observe that the lack of a viable SLA management framework renders a service provider unable to make wise decisions in forming an SLA, which could lead to service violations and violation penalties. To fill this gap, our second contribution is the proposal of the Optimized Personalized Viable SLA (OPV-SLA) framework which assists a service provider to form a viable SLA and start managing SLA violation before an SLA is formed and executed. The framework also assists a service provider to make an optimal decision in service formation and allocate the appropriate amount of marginal resources. We demonstrate the applicability of our framework in forming viable SLAs through experiments. From the evaluative results, we observe that our framework helps a service provider to form viable SLAs and later to manage them to effectively minimize possible service violation and penalties