Book Review: A Mechanistic Approach to Plankton Ecology

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Biomonitoring of air pollutants by using lichens (Evernia prunastri) in areas between Kenitra and Mohammedia cities in Morocco.

In this study, Evernia prunastri, a lichen growing in its natural habitat in Morocco was analysed for the concentration of five heavy metals (Fe, Pb, Zn, Cu and Cr) from eleven sites between Kenitra and Mohammedia cities. The control site was Dar Essalam, an isolated area with low traffic density and dense vegetation. In the investigated areas, the concentration of heavy metals was correlated with vehicular traffic, industrial activity and urbanization. The total metal concentration was highest in Sidi Yahya, followed by Mohammedia and Bouznika. The coefficient of variation was higher for Pb and lower for Cu, Zn and Fe. The concentrations of most heavy metals in the thalli differed significantly between sites (p<0.01). Principal component analysis (PCA) revealed a significant correlation between heavy metal accumulation and atmospheric purity index. This study demonstrated also that the factors most strongly affecting the lichen flora were traffic density, the petroleum industry and paper factories in these areas. Overall, these results suggest that the index of atmospheric purity and assessment of heavy metals in lichen thalli are good indicators of the air quality at the studied sites.

An investigation into the structure and bioavailability of a-tocopherol dispersions in Gelucire 44/14

In this investigation we describe the preparation, physical characterisation and in vivo behaviour of solid dispersions of a liquid nutraceutical, ±-tocopherol, in Gelucire 44/14 with a view to establishing whether dispersion in this matrix may provide a means of formulating a liquid drug in a solid dosage form while also improving the oral bioavailability. Using Vitamin E Preparation USP as the source of ±-tocopherol, dispersions were prepared using a melt-fusion method with active loadings up to 50% (w/w) and characterised using differential scanning calorimetry and optical microscopy. Capsules containing 300 IU ±-tocopherol were manufactured and the absorption profiles compared to a commercial soft gelatin capsule preparation in healthy human volunteers. Confocal laser scanning microscopy (CLSM) studies were performed in order to elucidate the mechanism by which drug release may be occurring. Differential scanning calorimetry studies indicated that the presence of the active had a negligible effect on the melting profile of the carrier, indicating limited miscibility between the two components, a conclusion supported by the microscopy studies. Similarly, the dispersions were shown to exhibit a glass transition corresponding to the incorporated drug, indicating molecular cooperativity and hence phase separation from the lipid base. Despite the phase separation, it was noted that capsules stored for 18 months under ambient conditions showed no evidence of leakage. Bioavailability studies in six healthy male volunteers indicated that the Gelucire 44/14 formulation showed an approximately two-fold increase in total ±-tocopherol absorption compared to the commercial preparation. Confocal laser scanning microscopy studies indicated that, on contact with water, the dispersions formed two interfacial layers, from which the Gelucire 44/14 disperses in the liquid medium as small particles. Furthermore, evidence was obtained for the dispersed material becoming incorporated into the hydrated lipid. In conclusion, the dispersion of the liquid drug in Gelucire 44/14 appears to allow the dual advantages of the preparation of a solid formulation and improved bioavailability of this material.

Is perception of upper body orientation based on the inertia tensor? Normogravity versus microgravity conditions

During lateral leg raising, a synergistic inclination of the supporting leg and trunk in the opposite direction to the leg movement is performed in order to preserve equilibrium. As first hypothesized by Pagano and Turvey (J Exp Psychol Hum Percept Perform, 1995, 21:1070-1087), the perception of limb orientation could be based on the orientation of the limb's inertia tensor. The purpose of this study was thus to explore whether the final upper body orientation (trunk inclination relative to vertical) depends on changes in the trunk inertia tensor. We imposed a loading condition, with total mass of 4 kg added to the subject's trunk in either a symmetrical or asymmetrical configuration. This changed the orientation of the trunk inertia tensor while keeping the total trunk mass constant. In order to separate any effects of the inertia tensor from the effects of gravitational torque, the experiment was carried out in normo- and microgravity. The results indicated that in normogravity the same final upper body orientation was maintained irrespective of the loading condition. In microgravity, regardless of loading conditions the same (but different from the normogravity) orientation of the upper body was achieved through different joint organizations: two joints (the hip and ankle joints of the supporting leg) in the asymmetrical loading condition, and one (hip) in the symmetrical loading condition. In order to determine whether the different orientations of the inertia tensor were perceived during the movement, the interjoint coordination was quantified by performing a principal components analysis (PCA) on the supporting and moving hips and on the supporting ankle joints. It was expected that different loading conditions would modify the principal component of the PCA. In normogravity, asymmetrical loading decreased the coupling between joints, while in microgravity a strong coupling was preserved whatever the loading condition. It was concluded that the trunk inertia tensor did not play a role during the lateral leg raising task because in spite of the absence of gravitational torque the final upper body orientation and the interjoint coupling were not influenced.

Use of physiotherapy and alternatives by children with cerebral palsy: a population study

Objectives: To describe the use of physiotherapy services and alternative therapies by a population of children with moderate to severe cerebral palsy (CP).
Design: Descriptive cross-sectional survey.
Subjects: A total of 212 parents of children aged 4–14 years with moderate to severe CP were identified from the Northern Ireland Cerebral Palsy Register (NICPR) and a random subsample of their paediatric physiotherapists.
Main measures: A standardized description of motor impairment or assessment form; a postal questionnaire to parents and paediatric physiotherapists (to validate parents’ reports of service use).
Response rates: In total, 85% of parent questionnaires were returned and 100% of paediatric physiotherapists responded.
Results: Service use among families was high; on average the families had contact with approximately seven services in a 6-month time interval. The overwhelming majority of children (96%) received physiotherapy during the school term and most (59%) received treatment at least twice a week for 30 min; 43% of children had their physiotherapy discontinued over the summer holidays. Over one-quarter (28%) of families had opted out of the NHS and bought alternatives like conductive education (21%) or private forms of conventional physiotherapy (16%). Children with more severe forms of CP, in special education, particularly at schools for physical disability, were high-intensity users of the physiotherapy service. Despite this, 74% of parents wanted more physiotherapy for their child.
Conclusions and implications: The demand for physiotherapy services is likely to continue given the relatively stable prevalence rate of CP, the proportion of children with disabling CP and the level of parent interest in the service. A number of quality aspects and gaps in the service have been identified.

La incidencia de los valores culturales en el voluntariado: el caso de Europa

La realidad del voluntariado es sumamente compleja hasta el punto de que resulta complicado definir y caracterizar el trabajo voluntario, dada la gran variedad de interpretaciones, motivaciones, variables sociodemográficas y aspectos culturales que configuran el perfil de los voluntarios. El objetivo de este trabajo es analizar la influencia conjunta de algunas variables sociodemográficas, así como de los valores culturales de índole secular o tradicional, sobre el perfil de los voluntarios en Europa. Además, se investiga qué variables orientan a los voluntarios hacia un determinado tipo de voluntariado u otro. Para ello se ha aplicado principalmente una metodología de regresión logística a partir de la información disponible en la European Value Study. Los resultados obtenidos ayudan a establecer una caracterización del voluntariado en Europa, y confirman la influencia de los valores culturales, en primer lugar, en la realización o no de trabajos de voluntariado, y en segundo lugar, en la elección que hacen estas personas del tipo de actividad con la que están comprometidos. Al analizar dos tipos de voluntariado de motivación supuestamente muy diferente, se concluye que existe un grupo de valores que influyen en ambos, aunque el sentido y la intensidad en la que lo hacen sea diferente; por otra parte, algunos valores tienen influencia o no en la realización de trabajos de voluntariado, dependiendo del tipo específico al que nos refiramos.