Effect of dietary phytate and microbial phytase on mineral and trace element bioavailability- a literature review

Phytic acid (PA) is the main phosphorus storage compound in cereals, legumes and oil seeds. In human populations where phytate-rich cereals such as wheat, maize and rice are a staple food, phytate may lead to mineral and trace element deficiency. Zinc appears to be the trace element whose bioavailability is most influenced by PA. Furthermore, several studies in humans as well as in monogastric animals clearly indicate an inhibition of non-haem iron absorption at marginal iron supply due to phytic acid. In fact PA seems to be, at least partly, responsible for the low absorption efficiency and high incidence of iron deficiency anaemia evident in most developing countries, where largely vegetarian diets are consumed Microbial phytases have provided a realistic means of improving mineral availability from traditionally high-phytate diets. In fact it has been consistently shown that Aspergillus phytases significantly enhance the absorption of calcium, magnesium and zinc in pigs and rats. Furthermore there are a few studies in humans indicating an improvement of iron bioavailability due to microbial phytase.

Human evolution, nutritional ecology and prebiotics in ancient diet

Modern studies of prebiotic non digestible carbohydrates continue to expand and demonstrate their colonic and systemic benefits. However, virtually nothing is known of their use among ancient populations. In this paper we discuss evidence for prebiotic use in the archaeological record from select areas of the world. It is suggested that members of our genus Homo would have had sufficient ecological opportunity to include prebiotic-bearing plants in diet as early as ~ 2 million years ago, but that significant dietary intake would not have taken place until the advent of technological advances that characterized the Upper Paleolithic of ~40,000 years ago. Throughout human evolution, hominid populations that diversified their diet to include prebiotic-bearing plants would have had a selective advantage over competitors.

Thinking skills in the early years: a literature review

Since 1999, thinking skills have been included in the National Curriculum alongside ‘key skills’ such as those to do with communication and information and communications technology (ICT). Thinking skills are expected to be developed at all key stages and centre on: information-processing skills, reasoning skills, enquiry skills, creative thinking skills and evaluation skills. This literature review consisted of three phases based on the following research questions: 1. What pedagogical approaches to developing generic thinking skills currently exist for children between the ages of three and seven? 2. What are the generic thinking skills that children are able to demonstrate at this age? 3. What is the relationship between these thinking capabilities and those that the pedagogical approaches aim to develop? The review covered post-2000 literature in the area of thinking skills in the early years. It provides an update of the evidence base upon which thinking skills approaches have been established, suggests areas where more evidence is needed and makes some practical recommendations for researchers, policy makers and practitioners.

Pollen analysis and planted ancient woodland restoration strategies: a case study from the Wentwood, southeast Wales,UK

This paper considers the contribution of pollen analysis to conservation strategies aimed at restoring planted ancient woodland. Pollen and charcoal data are presented from organic deposits located adjacent to the Wentwood, a large planted ancient woodland in southeast Wales. Knowledge of the ecosystems preceding conifer planting can assist in restoring ancient woodlands by placing fragmented surviving ancient woodland habitats in a broader ecological, historical and cultural context. These habitats derive largely from secondary woodland that regenerated in the 3rd–5th centuries A.D. following largescale clearance of Quercus-Corylus woodland during the Romano-British period. Woodland regeneration favoured Fraxinus and Betula. Wood pasture and common land dominated the Wentwood during the medieval period until the enclosures of the 17th century. Surviving ancient woodland habitats contain an important Fagus component that probably reflects an earlier phase of planting preceding conifer planting in the 1880s. It is recommended that restoration measures should not aim to recreate static landscapes or woodland that existed under natural conditions. Very few habitats within the Wentwood can be considered wholly natural because of the long history of human impact. In these circumstances, restoration should focus on restoring those elements of the cultural landscape that are of most benefit to a range of flora and fauna, whilst taking into account factors that present significant issues for future conservation management, such as the adverse effects from projected climate change.

Thalassaemia: its diagnosis and interpretation in past skeletal populations

The diagnosis of thalassaemia in archaeological populations has long been hindered by a lack of pathogonomic features, and the non-specific nature of cribra orbitalia and porotic hyperostosis. In fact, clinical research has highlighted more specific diagnostic criteria for thalassaemia major and intermedia based on changes to the thorax (‘rib-within-a-rib’ and costal osteomas). A recent re-examination of 364 child skeletons from Romano-British Poundbury Camp, Dorset revealed children with general ‘wasting’ of the bones and three children who demonstrated a variety of severe lesions (e.g. zygomatic bone and rib hypertrophy, porotic hyperostosis, rib lesions, osteopenia and pitted diaphyseal shafts) that are inconsistent with dietary deficiency alone, and more consistent with a diagnosis of genetic anaemia. Two of these children displayed rib lesions typical of those seen in modern cases of thalassaemia. The children of Poundbury Camp represent the first cases of genetic anaemia identified in a British archaeological population. As thalassaemia is a condition strongly linked to Mediterranean communities, the presence of this condition in a child from England, found within a mausoleum, suggests that they were born to wealthy immigrant parents living in this small Roman settlement in Dorset. This paper explores the diagnostic criteria for genetic anaemia in the archaeological literature and what its presence in ancient populations can contribute to our knowledge of past human migration.

Teaching assistants and pupils' academic and social engagement in mainstream schools: insights from systematic literature reviews

The last 20 years have seen a huge expansion in the additional adults working in classrooms in the UK, USA, and other countries. This paper presents the findings of a series of systematic literature reviews about teaching assistants. The first two reviews focused on stakeholder perceptions of teaching assistant contributions to academic and social engagement. Stakeholders were pupils, teachers, TAs, headteachers and parents. Perceptions focused on four principal contributions that teaching assistants contribute to: pupils’ academic and socio-academic engagement; inclusion; maintenance of stakeholder relations; and support for the teacher. The third review explored training. Against a background of patchy training provision both in the UK and the USA, strong claims are made for the benefits to TAs of training provided, particularly in building confidence and skills. The conclusions include implications for further training and the need for further research to gain an in-depth understanding as to precisely the manner in which TAs engage with children.

Integration of chaos theory and mathematical models in building simulation: Part I: Literature review

Current mathematical models in building research have been limited in most studies to linear dynamics systems. A literature review of past studies investigating chaos theory approaches in building simulation models suggests that as a basis chaos model is valid and can handle the increasingly complexity of building systems that have dynamic interactions among all the distributed and hierarchical systems on the one hand, and the environment and occupants on the other. The review also identifies the paucity of literature and the need for a suitable methodology of linking chaos theory to mathematical models in building design and management studies. This study is broadly divided into two parts and presented in two companion papers. Part (I) reviews the current state of the chaos theory models as a starting point for establishing theories that can be effectively applied to building simulation models. Part (II) develops conceptual frameworks that approach current model methodologies from the theoretical perspective provided by chaos theory, with a focus on the key concepts and their potential to help to better understand the nonlinear dynamic nature of built environment systems. Case studies are also presented which demonstrate the potential usefulness of chaos theory driven models in a wide variety of leading areas of building research. This study distills the fundamental properties and the most relevant characteristics of chaos theory essential to building simulation scientists, initiates a dialogue and builds bridges between scientists and engineers, and stimulates future research about a wide range of issues on building environmental systems.