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

Protection of cattle from Culicoides spp. in Australia by shelter and chemical treatments

Trials were conducted in three regions of Australia to investigate the potential for improvised shelters and chemical treatments to reduce feeding by Culicoides on cattle and thereby minimise the risk of bluetongue transmission during transport of cattle to ports. Various designs and combinations of roofs and walls were placed around penned cattle. Chemical treatments were applied to other penned cattle. Culicoides were collected from the cattle by vacuum samplers or by light traps in the pens. Roofs alone did not consistently reduce the numbers of Culicoides brevitarsis or C. fulvus and increased the numbers of C. actoni collected. Walls alone reduced the numbers of C. wadai but not C. brevitarsis. Roofs and walls in combination reduced the numbers of C. brevitarsis and C. wadai. The chemical treatments ‘Flyaway’ (a blend of repellents) and fenvalerate reduced the numbers of C. brevitarsis and C. wadai up to 52 h post treatment

Quantum Phase Transitions and the Extended Coupled Cluster Method

We discuss the application of an extended version of the coupled cluster method to systems exhibiting a quantum phase transition. We use the lattice O(4) non-linear sigma model in (1+1)- and (3+1)-dimensions as an example. We show how simple predictions get modified, leading to the absence of a phase transition in (1+1) dimensions, and strong indications for a phase transition in (3+1) dimensions

Steady State Resource Allocation Analysis of the Stochastic Diffusion Search

This article presents the long-term behaviour analysis of Stochastic Diffusion Search (SDS), a distributed agent based Swarm Intelligence meta-heuristic for best-fit pattern matching. SDS operates by allocating simple agents into different regions of the search space. Agents independently pose hypotheses about the presence of the pattern in the search space and its potential distortion. Assuming a compositional structure of hypotheses about pattern matching agents perform an inference on the basis of partial evidence from the hypothesised solution. Agents posing mutually consistent hypotheses about the pattern sup- port each other and inhibit agents with inconsistent hypotheses. This results in the emergence of a stable agent population identifying the desired solution. Positive feedback via diffusion of information between the agents significantly contributes to the speed with which the solution population is formed. The formulation of the SDS model in terms of interacting Markov Chains enables its characterisation in terms of the allocation of agents, or computational resources. The analysis characterises the stationary probability distribution of the activity of agents, which leads to the characterisation of the solution population in terms of its similarity to the target pattern

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

Recruiting robots perform stochastic diffusion search

A Letter to Nature demonstrated that a simple ant-inspired ‘tandem calling’ recruitment mechanism improved task performance in a group of robots. In these experiments a group of robots attempt to locate ‘food’ and return it to base. On its return a successful robot tries to recruit another to help exploit its find. As a result a population of robots rapidly expands to exploit the resource, resulting in greater foraging efficacy. In this note we observe that the type of recruitment and information sharing mechanism employed by the robots is one instance of a general class of Swarm Intelligence parallel search and optimisation methods, known as Stochastic Diffusion Search (SDS)

Dynamical study on polaron formation in a metal/polymer/metal structure

By considering a metal/polymer/metal structure within a tight-binding one-dimensional model, we have investigated the polaron formation in the presence of an electric field. When a sufficient voltage bias is applied to one of the metal electrodes, an electron is injected into the polymer chain, then a self-trapped polaron is formed at a few hundreds of femtoseconds while it moves slowly under a weak electric field (not larger than $$ V/cm). At an electric field between $1.0\times 10^4$ V/cm and $$ V/cm, the polaron is still formed, since the injected electron is bounded between the interface barriers for quite a long time. It is shown that the electric field applied at the polymer chain reduces effectively the potential barrier in the metal/polymer interface

A light-front coupled cluster method

A new method for the nonperturbative solution of quantum field theories is described. The method adapts the exponential-operator technique of the standard many-body coupled-cluster method to the Fock-space eigenvalue problem for light-front Hamiltonians. This leads to an effective eigenvalue problem in the valence Fock sector and a set of nonlinear integral equations for the functions that define the exponential operator. The approach avoids at least some of the difficulties associated with the Fock-space truncation usually used.Comment: 8 pages, 1 figure; to appear in the proceedings of LIGHTCONE 2011, 23-27 May 2011, Dalla