Pasture investigations in the sandy forest country of north-west Queensland. 1. Nutritional requirements

The effects of several nutrients on Townsville stylo (Stylosanthes humilis) were assessed in two field experiments near Normanton in north-west Queensland. In the first experiment, the response to three rates of phosphorus in the presence and absence of potassium, sulphur,molybdenum, zinc, magnesium-plus-manganese and copper-plus-boron was examined on a sandy yellow earth soil of the Mayvale land system. In the second experiment, on a mottled grey earth soil, four rates of phosphorus and zinc and two rates of potassium were c~mpared

Ascaris lumbricoides: The risk factors and effects on growth of schoolchildren within Samaru, Zaria, Nigeria

Intestinal helminthiasis affects children’s health and physical growth. Finding the prevalence of Ascaris lumbricoides, risk factors and effects on growth of children in Samaru, Zaria were the foci of this study. Fresh faecal samples were collected from 203 consented children in seven selected schools. Weight and height data were measured and body mass index was calculated for each child. Samples were processed by formol-ether concentration technique and examined for ova of Ascaris lumbricoides with light microscope. Data were analyzed by statistical tools. Overall prevalence of Ascaris lumbricoides was 2.0%. The infection was absent in children from private schools, but those from public schools were significantly infected (P=0.042, OR >1). Male children were more infected (2.1%) than females (1.9%). Children below 10 years old had no ascariasis, while children of 10-11 and 12-13 years old had 2.5% and 2.9% infections respectively. Children who eat raw vegetables (OR =1.021) or work on farms (OR =2.636) were more at risk of ascariasis. No sign/symptom was associated with ascariasis. Ascaris lumbricoides was present only in children whose body weights were ≤38.0kg with significantly low body mass index of <18.50 (OR >1). Ascariasis is preventable given proper environmental sanitation, safe water and adequate sanitary facilities

Risk factors and effects of hookworm infections on anthropometric indices of school children in Samaru, Zaria, Nigeria

Rural communities in Nigeria suffer a great deal of parasitic infections. The effect is severe on children. Parasitic infections affect the health of schoolchildren by causing malnutrition, anaemia, reduced cognitive ability and poor performance in school. This study was aimed at assessing the prevalence of hookworm infections, associated risk factors and their effects on anthropometric indices of schoolchildren in Samaru, Zaria. Children across public and private schools were enlightened about the disease. Fresh morning faecal samples were collected from each of 203 consented pupils. The samples were examined for hookworm eggs by formol-ether concentration technique. Prevalence of hookworms was 4.9%. Children in four out of seven schools were found with hookworm infections (P=0.000). Children from public schools were significantly more infected with hookworms (7.9%, P=0.050) than those in the private schools. Male schoolchildren had higher hookworm infections (5.8%) than the females (4.7%, P>0.05). The youngest children of age 6-7 years old were the most infected (9.1%); followed by those of 10-11 years old who had 5.8% infections. Children who walked barefooted (6.5%), consumed raw vegetables (5.1%) or engaged in farming (5.3%) were more infected with hookworms than those who did not, but the relationship was not significant (P>0.00). Only fever (3.0%) was found among infected children (P=0.582), other symptoms did not occur among those infected with the hookworms. Children with weight of 39-48kg had the highest infection of 8.0%. Weight, height and BMI were not statistically associated with hookworm infections among the children. However, most of the children (87.2%) had underweight BMI

The Extended Coupled Cluster Treatment of Correlations in Quantum Magnets

The spin-half XXZ model on the linear chain and the square lattice are examined with the extended coupled cluster method (ECCM) of quantum many-body theory. We are able to describe both the Ising-Heisenberg phase and the XY-Heisenberg phase, starting from known wave functions in the Ising limit and at the phase transition point between the XY-Heisenberg and ferromagnetic phases, respectively, and by systematically incorporating correlations on top of them. The ECCM yields good numerical results via a diagrammatic approach, which makes the numerical implementation of higher-order truncation schemes feasible. In particular, the best non-extrapolated coupled cluster result for the sublattice magnetization is obtained, which indicates the employment of an improved wave function. Furthermore, the ECCM finds the expected qualitatively different behaviours of the linear chain and the square lattice cases.Comment: 22 pages, 3 tables, and 15 figure

Renormalization of Hamiltonian Field Theory; a non-perturbative and non-unitarity approach

Renormalization of Hamiltonian field theory is usually a rather painful algebraic or numerical exercise. By combining a method based on the coupled cluster method, analysed in detail by Suzuki and Okamoto, with a Wilsonian approach to renormalization, we show that a powerful and elegant method exist to solve such problems. The method is in principle non-perturbative, and is not necessarily unitary.Comment: 16 pages, version shortened and improved, references added. To appear in JHE

The ‘mosaic habitat’ concept in human evolution: past and present

The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the ‘mosaic habitat’ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept – loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial area– in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term ‘mosaic’ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970’s due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of ‘mosaic’ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution

Rho GTPase function in flies: insights from a developmental and organismal perspective.

Morphogenesis is a key event in the development of a multicellular organism and is reliant on coordinated transcriptional and signal transduction events. To establish the segmented body plan that underlies much of metazoan development, individual cells and groups of cells must respond to exogenous signals with complex movements and shape changes. One class of proteins that plays a pivotal role in the interpretation of extracellular cues into cellular behavior is the Rho family of small GTPases. These molecular switches are essential components of a growing number of signaling pathways, many of which regulate actin cytoskeletal remodeling. Much of our understanding of Rho biology has come from work done in cell culture. More recently, the fruit fly Drosophila melanogaster has emerged as an excellent genetic system for the study of these proteins in a developmental and organismal context. Studies in flies have greatly enhanced our understanding of pathways involving Rho GTPases and their roles in development