Seafood inclusion in commercial main meal early years' food products

Acknowledgement We are grateful to the food manufacturers for answering queries and supplying missing nutritional information. Source of funding The study was funded by the Seafish and Interface Food and Drink as part of a Doctorate Scholarship undertaken at the University of Aberdeen. © 2015 John Wiley & Sons Ltd.

Seafood inclusion in commercial main meal early years' food products

Acknowledgement We are grateful to the food manufacturers for answering queries and supplying missing nutritional information. Source of funding The study was funded by the Seafish and Interface Food and Drink as part of a Doctorate Scholarship undertaken at the University of Aberdeen. © 2015 John Wiley & Sons Ltd.

Caracterização do estado de saúde oral dos idosos abrangidos pelo projeto “sorrisos de porta em porta”

A esperança média de vida tem vindo a aumentar, resultando no envelhecimento da população mundial e, consequentemente, num aumento das populações com idades mais avançadas. Torna-se, por isso, importante estudar as especificidades do envelhecimento para que possamos trazer bem-estar e qualidade de vida a esta população que é cada vez mais numerosa, já que o envelhecimento traz mudanças a nível do corpo humano que se vão repercutir na saúde geral e na saúde oral. Os idosos apresentam, normalmente, pobres condições de saúde oral, sendo as doenças orais que mais acometem a esta população a perda dentária, a experiência de cárie, as altas taxas de prevalência de doença periodontal, a xerostomia e o pré-cancro/cancro oral. Além do envelhecimento populacional, têm sido notadas, ao longo do tempo, mudanças na estrutura familiar. Tudo isto leva a que o número de idosos institucionalizados aumente. Neste estudo foram utilizados dados, ainda não publicados, recolhidos no âmbito do projeto Sorrisos de Porta em Porta, que pertence à Mundo a Sorrir – Associação de Médicos Dentistas Portugueses. Este projeto visa a promoção de hábitos de saúde oral na população idosa e atua através da realização de ações de sensibilização subordinadas à temática da saúde oral no idoso e realização de rastreios de saúde oral aos idosos que se encontrem no âmbito de uma reposta social. Foram observados um total de 3586 idosos com idade igual ou superior a 65 anos, onde 70,3% eram do género masculino. A idade média (desvio padrão) encontrada foi 81,9 (±7,5) e a maioria referiu ser autónoma nos cuidados de higiene oral, no entanto, observou-se que grande parte dos idosos não realizava a escovagem diária e mais de metade destes disse não sentir necessidade de o fazer. Observou-se também, que apenas 13,7% tinham tido a sua última consulta de Medicina Dentária nos últimos 6 meses e a maioria disse visitar o Médico Dentista por razões de dor dentária. A média (desvio padrão) obtida para o Índice CPOd foi 26,3 (±8,4), sendo a componente “Perdidos” a mais significativa. Relativamente ao Índice de Placa, a maioria apresentava um acúmulo de placa bacteriana maior de 1/3 mas menor de 2/3. Quanto ao tipo de desdentação a maior percentagem era a de idosos desdentados parciais sem prótese. Foi também realizada uma pesquisa bibliográfica. Com este estudo concluiu-se que o estado de saúde oral dos idosos é bastante pobre consequência de uma pobre higiene oral e de falta de cuidados de saúde oral. Há uma grande necessidade de se instruir as pessoas relativamente à importância da Medicina Dentária e dos problemas que uma má saúde oral pode trazer para a saúde em geral.

Inbound logistics, the last mile and intermodal high capacity transport – the case of Jula in Sweden

Some of the biggest challenges for intermodal transport competitiveness are the extra handling costs and pre- and post-haulage costs. This paper investigates the use of Intermodal High Capacity Transport (IHCT) for the intermodal transport chain in general and to pre-and post-haulage in particular. The aim is not only to measure the cost reductions from using larger vehicles but to understand how better management of inbound flows through increased integration of logistics processes can increase the efficiency of the last mile. The paper analyses the haulage of two 40 foot containers simultaneously when part of an intermodal transport chain. Data were collected from a demonstration project in Sweden, where permission was obtained to use longer vehicles on an approved route to and from the nearest intermodal terminal. Results indicate substantial cost savings from using longer vehicles for pre- and post-haulage. In addition, the business model whereby the shipper purchased their own chassis and permission was obtained to access the terminal after hours for collecting pre-loaded chassis brought additional cost and planning benefits. The total cost saving was significant and potentially eliminates the cost deficit associated with the last mile.

Inbound logistics, the last mile and intermodal high capacity transport.

Some of the biggest challenges for intermodal transport competitiveness are the extra handling costs and pre- and post-haulage costs. This paper investigates the use of Intermodal High Capacity Transport (IHCT) for the intermodal transport chain in general and to pre-and post-haulage in particular. The aim is not only to measure the cost reductions from using larger vehicles but to understand how better management of inbound flows through increased integration of logistics processes can increase the efficiency of the last mile. The paper analyses the haulage of two 40 foot containers simultaneously when part of an intermodal transport chain. Data were collected from a demonstration project in Sweden, where permission was obtained to use longer vehicles on an approved route to and from the nearest intermodal terminal. Results indicate substantial cost savings from using longer vehicles for pre- and post-haulage. In addition, the business model whereby the shipper purchased their own chassis and permission was obtained to access the terminal after hours for collecting pre-loaded chassis brought additional cost and planning benefits. The total cost saving was significant and potentially eliminates the cost deficit associated with the last mile.

Características de las malformaciones congénitas en recién nacidos del Hospital Vicente Corral Moscoso, 2010-2014

Objetivo Determinar la prevalencia de las malformaciones congénitas y las características de las madres y de los recién nacidos malformados en el Hospital Vicente Corral Moscoso. Metodología Se realizó un estudio de tipo descriptivo (se determinó la prevalencia por año), se revisaron las historias clínicas de las madres con recién nacidos entre el periodo del 2010 al 2014. Para recolectar la información se empleó un formulario pre elaborado, los datos se agruparon según la clasificación del CIE-10 y se tabularan usando Microsoft Excel. Para el análisis de los datos se utilizó el software estadístico SPSS versión 15. Se describieron las variables del estudio de acuerdo a las medidas estadísticas apropiadas. Resultados La prevalencia de las malformaciones congénitas fue de 1.70 por cada 100 recién nacidos. Las mujeres entre 20 a 24 años, presentaron el mayor porcentaje de recién nacidos malformados con un 34.95%. Los recién nacidos malformados fueron mayoritariamente del sexo masculino con 53.83%. El grupo de malformación más frecuente fueron las malformaciones y deformidades congénitas del sistema osteomuscular con 18.88%, de las cuales la gastrosquisis fue la más frecuente, representada por el 4.85%. El síndrome polimalformativo fue el tipo de malformación congénita con el mayor porcentaje con un 10.71%. Conclusiones El presente estudio revela que la prevalencia encontrada de recién nacidos con malformaciones congénitas, fue similar a investigaciones previas a nivel regional y local. Se incluyeron únicamente las malformaciones que constituyen alteraciones morfológicas evidentes, encontrándose una mayor frecuencia del síndrome polimalformativo

Les impacts d’un programme de chant choral sur le bien-être et la cognition de personnes âgées en perte d’autonomie

Résumé : Le chant choral serait bénéfique à tout âge : cette étude choisit d’en mesurer les impacts auprès de personnes très âgées. Un devis quantitatif quasi-expérimental à trois groupes fut adopté : la Chorale, l’Hebdo-Bistro (ateliers et conférences, groupe de comparaison), et le groupe Témoin. L’étude longitudinale, intergénérationnelle, comporta trois saisons. La cognition (Mattis, 3MS, Trail Making, empan numérique, fluences formelle, catégorielle), l’humeur (bien-être général, dépression (GDS)), l’autoefficacité (GSES) et l’autonomie (QAF) furent mesurées à trois reprises (pré, post, 2e post). En outre, des mesures hebdomadaires furent administrées concernant la santé physique (consultations médicales, médicaments, chutes) et la participation sociale (activités). L’analyse intergroupe ne rapporta aucune différence significative. Les comparaisons intragroupe montrèrent une amélioration significative pour la Chorale (3MS et activités sociales), et une tendance d’amélioration pour la Chorale et l’Hebdo-Bistro (fluence formelle). Bien que le petit échantillon (n=21) exclue toute généralisation, les résultats demeurent inspirants en contexte de vieillissement populationnel.

Calagem e adubação fosfatada para formação de mudas de araçá-boi.

O araçá-boi (Eugenia stipitata McVaugh) é uma espécie frutífera cultivada em escala doméstica na região Amazônica. Entretanto, pouco se conhece sobre seu requerimento nutricional na fase de muda. O objetivo deste trabalho foi avaliar o efeito da calagem e da adubação fosfatada sobre o crescimento e nutrição de mudas de araçá-boi. O experimento foi conduzido em viveiro, com amostras de um Latossolo Amarelo distrófico, em delineamento experimental de blocos casualizados e esquema fatorial 5 x 5: cinco doses de calcário (0; 1,37; 2,83; 4,29 e 5,75 g por muda) e cinco de fósforo (0, 100, 200, 400 e 600 mg kg-1 de P), com quatro repetições. Dez meses após o transplante, foram avaliados o crescimento em altura e em diâmetro, a matéria seca da parte aérea e das raízes e o acúmulo de nutrientes na parte aérea das plantas. As doses de calcário influenciaram significativamente a altura, o diâmetro, a matéria seca da parte aérea, das raízes e total das mudas. As doses de fósforo influenciaram apenas o crescimento em diâmetro a matéria seca da parte aérea e total. Houve efeito significativo das doses de calcário e de fósforo sobre o acúmulo de macro e micronutrientes na parte aérea das plantas, exceto para o Cu, influenciado apenas pelas doses de calcário. O melhor desenvolvimento das mudas de araçá-boi pode ser obtido com a aplicação de até 3,77 g de calcário e 6,21 g de superfosfato triplo por muda.

Formulação de grautes leves para a cimentação de poços de petróleo onshore

Grautes are dry mixes with hydraulic characteristics widely used in construction. This material comprises cement, mineral additives and dosed in accordance with the desired properties. The use of grautes in cementing oil wells potentially increases the precision in the composition of the mixture, since it is requires only the addition of the mixing water before its pumping. Such benefit may be availed in cementing wells since the formulations grautes meet the temperature and pressure characteristics typical of wells. The objective of this study is to evaluate the effect of adding different percentages of industrial minerals properties of light grautes for onshore oil wells. For the formulation of the employees were grautes light industrial minerals and waste minerals abundant in the Northeast, in addiction to Portland cement and chemical additives Special class. Grautes were formulated with densities between 1.55 g/cm3 (13.0 lb/gal) and 1.68 g/cm3 (14 lb/gal). Tests results showed that grautes with higher density in the range studied meet the specifications for cementation of shallow wells onshore. The compositions lighter can also be adjusted for applying the material in the cementation of oil wells

Formulação de grautes leves para a cimentação de poços de petróleo onshore

Grautes are dry mixes with hydraulic characteristics widely used in construction. This material comprises cement, mineral additives and dosed in accordance with the desired properties. The use of grautes in cementing oil wells potentially increases the precision in the composition of the mixture, since it is requires only the addition of the mixing water before its pumping. Such benefit may be availed in cementing wells since the formulations grautes meet the temperature and pressure characteristics typical of wells. The objective of this study is to evaluate the effect of adding different percentages of industrial minerals properties of light grautes for onshore oil wells. For the formulation of the employees were grautes light industrial minerals and waste minerals abundant in the Northeast, in addiction to Portland cement and chemical additives Special class. Grautes were formulated with densities between 1.55 g/cm3 (13.0 lb/gal) and 1.68 g/cm3 (14 lb/gal). Tests results showed that grautes with higher density in the range studied meet the specifications for cementation of shallow wells onshore. The compositions lighter can also be adjusted for applying the material in the cementation of oil wells

Otimização e análise mecânica de pastas geopoliméricas para uso em poços sujeitos à injeção cíclica de vapor

Oil wells subjected to cyclic steam injection present important challenges for the development of well cementing systems, mainly due to tensile stresses caused by thermal gradients during its useful life. Cement sheath failures in wells using conventional high compressive strength systems lead to the use of cement systems that are more flexible and/or ductile, with emphasis on Portland cement systems with latex addition. Recent research efforts have presented geopolymeric systems as alternatives. These cementing systems are based on alkaline activation of amorphous aluminosilicates such as metakaolin or fly ash and display advantageous properties such as high compressive strength, fast setting and thermal stability. Basic geopolymeric formulations can be found in the literature, which meet basic oil industry specifications such as rheology, compressive strength and thickening time. In this work, new geopolymeric formulations were developed, based on metakaolin, potassium silicate, potassium hydroxide, silica fume and mineral fiber, using the state of the art in chemical composition, mixture modeling and additivation to optimize the most relevant properties for oil well cementing. Starting from molar ratios considered ideal in the literature (SiO2/Al2O3 = 3.8 e K2O/Al2O3 = 1.0), a study of dry mixtures was performed,based on the compressive packing model, resulting in an optimal volume of 6% for the added solid material. This material (silica fume and mineral fiber) works both as an additional silica source (in the case of silica fume) and as mechanical reinforcement, especially in the case of mineral fiber, which incremented the tensile strength. The first triaxial mechanical study of this class of materials was performed. For comparison, a mechanical study of conventional latex-based cementing systems was also carried out. Regardless of differences in the failure mode (brittle for geopolymers, ductile for latex-based systems), the superior uniaxial compressive strength (37 MPa for the geopolymeric slurry P5 versus 18 MPa for the conventional slurry P2), similar triaxial behavior (friction angle 21° for P5 and P2) and lower stifness (in the elastic region 5.1 GPa for P5 versus 6.8 GPa for P2) of the geopolymeric systems allowed them to withstand a similar amount of mechanical energy (155 kJ/m3 for P5 versus 208 kJ/m3 for P2), noting that geopolymers work in the elastic regime, without the microcracking present in the case of latex-based systems. Therefore, the geopolymers studied on this work must be designed for application in the elastic region to avoid brittle failure. Finally, the tensile strength of geopolymers is originally poor (1.3 MPa for the geopolymeric slurry P3) due to its brittle structure. However, after additivation with mineral fiber, the tensile strength became equivalent to that of latex-based systems (2.3 MPa for P5 and 2.1 MPa for P2). The technical viability of conventional and proposed formulations was evaluated for the whole well life, including stresses due to cyclic steam injection. This analysis was performed using finite element-based simulation software. It was verified that conventional slurries are viable up to 204ºF (400ºC) and geopolymeric slurries are viable above 500ºF (260ºC)

Efeito da incorporação de diatomita na estabilidade e permeabilidade de compósitos cimentíceos espumados aplicados a poços de petróleo

Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

The effect of offering an energy and protein supplement to grazing canchim beef cows either postpartum or both pre- and postpartum on lipid blood metabolites and folliculogenesis

This study was designed to evaluate the effect of nutritional supplementation offered during the pre- and postpartum periods on serum cholesterol, triglycerides and total lipids of Canchim beef cows and their relationship with folliculogenesis. Thirty cows with predicted calving date between September and October, kept in pastures of Brachiaria brizantha cv. Marandu together with their calves, were randomly distributed into three experimental groups: the first received only a mineral mixture (Control Group, CG); the second group received a concentrate with 16% crude protein/kg dry matter (DM) and 3000 kcal digestible energy/kg DM offered for 45 days prepartum and 120 days postpartum (PREG); the third group received the concentrate from parturition until the 120th day postpartum (POSG). Consumption was estimated at 1% of body weight, and each cow received approximately 4.0 kg/day (fresh weight) of supplement. Blood samples were taken and an ultrasound examination of the ovaries was performed twice a week until the 60th day postpartum. The body condition score (BCS) and the weight of the cows were recorded at 15-day intervals from calving until the 60th day postpartum. Data are presented as mean +/- SEM. Mean weight and BCS at calving were, respectively, 448 +/- 54.9 kg and 6.2 +/- 0.25 (PREG); 432 +/- 71.1 kg and 5.5 +/- 0.69 (POSG); and 434 +/- 66.4 kg and 5.5 +/- 0.69 (CG). Total cholesterol (TC), triglycerides (TRIG) and total lipids (TLIP) were measured using colorimetry until the 60th day postpartum. TC averages were PREG 186 +/- 62.6 mg/dL, POSG 159 +/- 43.1 mg/dL and CG 133 +/- 35.1 mg/dL (P < 0.05). For TRIG, the means were PREG 29 +/- 11.3 mg/dL (P < 0.05), POSG 24 +/- 8.1 mg/dL and CG 26 +/- 12.1 mg/dL (P > 0.05). Serum concentrations of TLIP were PREG 588 +/- 145.6 mg/dL, POSG 512 +/- 137.6 mg/dL and CG 452 +/- 122.4 mg/dL (P < 0.05). The first dominant follicle (DF) was identified on Day 21 +/- 10.3 (PREG), 36 +/- 28.5 (POSG) and 51 +/- 32.8 (CG) after calving. The difference between PREG and CG was significant (P < 0.05). TC was positively correlated with the calving to first estrus interval (P < 0.05). Results showed that nutritional supplementation before parturition assured good body condition at calving and suggested that it was effective at increasing cholesterol availability to maintain ovarian follicle function and to favor earlier resumption of ovarian activity. (C) 2010 Published by Elsevier B.V.

Aditivos na ensilagem do capim-elefante. III. Valor nutritivo e consumo voluntário e digestibilidade aparente em ovinos

The intake, the apparent digestibility and the nutritive value of elephant grass (Pennisetum purpureum Schum.) silages prepared with the addition of 0, 8, 16 and 24% of ground ear corn with husks, wheat bran and saccharin, dry weight of additive/wet weight of green chop upon the silage were evaluated. A randomized block design with three replications, in a factorial arrangement (3 additives x 4 levels) was used. As experimental silos, 200-liter plastic vessels were used. Sheep weighing approximately 50 kg, kept in individual cages, receiving water and mineral mixture ad libitum, were used to measure the intake and apparent digestibility of silages. There was a ten-day period of adaptation to the experiment conditions. The voluntary intake of the silages was determined by the mean of the intake observed in the last three days of a ten-day period. The fecal collection period lasted for seven days. In this period the animals were fed 80% of the observed intake obtained in the previous phase. The dry matter intake increased as the levels of the additives in the silages were increased. The digestibility of the wall cell components decreased as the rates of the additives in the ensilage process increased. The silages prepared with wheat bran or ground ear corn with husks showed higher nutritive value than the ones with saccharin.

Bioremediation of PAHs - Limitations and soultions

Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.