The great outdoors: how a green exercise environment can benefit all

The studies of human and environment interactions usually consider the extremes of environment on individuals or how humans affect the environment. It is well known that physical activity improves both physiological and psychological well-being, but further evidence is required to ascertain how different environments influence and shape health. This review considers the declining levels of physical activity, particularly in the Western world, and how the environment may help motivate and facilitate physical activity. It also addresses the additional physiological and mental health benefits that appear to occur when exercise is performed in an outdoor environment. However, people's connectedness to nature appears to be changing and this has important implications as to how humans are now interacting with nature. Barriers exist, and it is important that these are considered when discussing how to make exercise in the outdoors accessible and beneficial for all. The synergistic combination of exercise and exposure to nature and thus the 'great outdoors' could be used as a powerful tool to help fight the growing incidence of both physical inactivity and non-communicable disease. © 2013 Gladwell et al.; licensee BioMed Central Ltd

Estimating the critical and sensitive periods of investment in early childhood: A methodological note

This paper provides an overview of different quantitative methods available for the statistical analysis of longitudinal data regarding child development, and in particular the identification of critical and sensitive periods for later abilities. It draws heavily on the work on human skill formation developed by the economist James Heckman, which treats ability as a latent variable and explains its formation through the simultaneous estimation of structural equations of investments and achieved abilities across time. We distinguish between two specifications of the ability formation function. One of them (the ‘recursive’) format explains current ability as a function of the ability and investment at the immediately preceding period. The other (the ‘non-recursive’) format explains current ability as a function of a series of past investments. In order to fully examine critical and sensitive periods of investments, the non-recursive formulation needs to be used. Furthermore, true abilities of an individual cannot be directly observed: what we observe are the test scores, for example, on reading and writing. We outline an approach based on structural models that treats actual test scores as measurements of the latent ability variable, and show how it can be used in the recursive and non-recursive formulation. In order to fully examine critical and sensitive periods of investments, we argue that the non-recursive formulation of this structural model is necessary. However, the non-recursive formulation requires more data than the recursive formulation, and to the best of our knowledge, has never been used in the identification of critical and sensitive periods in early childhood development. (254wds

Ya no es un niño: del Reino Unido a Afganistán

Los jóvenes afganos obligados a regresar a Kabul tras haber pasado sus años de formación en el Reino Unido encuentran riesgos particulares y carecen de apoyo personalizado a su regreso

Stable and Efficient Structures for the Content Production and Consumption in Information Communities

Real-world information communities exhibit inherent structures that characterize a system that is stable and efficient for content production and consumption. In this paper, we study such structures through mathematical modelling and analysis. We formulate a generic model of a community in which each member decides how they allocate their time between content production and consumption with the objective of maximizing their individual reward. We define the community system as "stable and efficient" when a Nash equilibrium is reached while the social welfare of the community is maximized. We investigate the conditions for forming a stable and efficient community under two variations of the model representing different internal relational structures of the community. Our analysis results show that the structure with "a small core of celebrity producers" is the optimally stable and efficient for a community. These analysis results provide possible explanations to the sociological observations such as "the Law of the Few" and also provide insights into how to effectively build and maintain the structure of information communities.Comment: 21 page

Caregivers’ Role Definition and Practices in the Stimulation of Children’s Emergent Reading Development in Ruiru, Kenya

Emergent reading refers to the reading related developments that occur before formal reading instruction. Although research on this concept exists in other countries, It is a relatively new concept in Kenya and for this reason has not received much attention in research. Recent studies in Kenya are consistently reporting poor reading achievements among children in primary school. These studies show that most of the reading difficulties begin from early childhood years and continue impacting on children’s reading attainment in their later school years.  This implies that there is need to establish issues surrounding reading development from children’s early years.  The study from which this paper draws investigated the current status of caregiver perceptions and practices with 30 to 42 months old children around print. The study found that caregivers largely lacked knowledge about children’s emergent reading development and their role in it. Caregivers’ perceptions about their role in children’s emergent reading development were largely negative. These findings implied that children are receiving little or no stimulation to enhance their early reading development. Consequently, they may start preschool with little or no interest and motivation to read. This may explain the reading difficulties that recent research has reported. Important recommendations arising from the study include the need to sensitize caregivers’ and to help them redefine their role in children’s emergent reading development are the key recommendations discussed in this paper. Key words:  Emergent reading, Stimulation, Children, Caregivers, Role Definitio

Practical implementation of the durability index-based performance approach

Includes abstract.Includes bibliographical references.The purpose of this study was to examine the validity of Durability Index (DI) based performance specifications as a practical approach in the control of quality, with regard to durability, in reinforced concrete structures. The DI-based specifications entail provisions for limiting values on the relevant DI test parameters (oxygen permeability index (OPI), water sorptivity index (WSI) or chloride conductivity index (CCI)) and cover depth, depending on exposure conditions for a given service life. These specifications have been implemented by the South African National Roads Agency Limited (SANRAL) in major infrastructure projects e.g. the Gauteng Freeway Improvement Project (GFIP), which provided the main case studies considered in attaining the research objective

Concurrent Whitening and Orthodontic Treatment

The aim was to evaluate whether a whitening system, when used during the final stages of orthodontics, would yield results comparable to whitening alone. Patients were assigned to either the control (n=20) or experimental (n=26) groups. At T1, patients were given a ten day supply of Trèswhite⢠by Opalescence®, instructions on use, and initial shade determination was made and photographs were taken. At T2 and T3, shade determination was accomplished and updated photographs were taken. Whitening of the teeth occurred in both groups on average, but significantly more whitening was experienced in the experimental group (p \u3c 0.004). An average of 87% of teeth whitened during orthodontic treatment compared to 97% of control teeth (p \u3c 0.01) were judged to be uniform in appearance. In conclusion, the data do not contraindicate the concurrent accomplishment of teeth whitening during orthodontic treatment

The effect of high lethal temperatures on the muscle of the crayfish, astacus pallipes lereboullet; a biochemical and electrophysiological

The phenomenon of temperature adaptation, as measured by the mobility of the heat death point, was demonstrated in Aatacus pallipes Lereboullet. Analysis of muscle, haemolymph and environment during lethal high temperature exposure showed dramatic Na(^+) and K(^+) concentration changes in all three compartments. In all cases the monovalent cations showed a net movement down their respective electro-chemical gradients, although this was sometimes only observed after a brief initial period during which the ions tended to exhibit a net movement up their electro-chemical gradients. The results indicated that heat death occurred when the haemolymph K(^+) concentration rose to about 9 mM. No relationship between the haemolymph Na(^+) concentration and the heat death point was observed. Electrophysiological experiments indicated that lethal high temperatures caused an increase in the conductivity (-, permeability) of the sarcolemma following comparable exposure times to those causing heat death in the whole animal. The Mg(^++)activated ATPase (EC 3.6.1.3.) which is involved in the control of sarcolemmal permeability was shown to be inactivated by lethal high temperatures. It was therefore concluded that the increased sarcolemmal permeability was caused by the thermal inactivation of this enzyme. The spontaneous activity of the CNS was only slightly affected by exposure to lethal high temperatures. Raising the extracellular K* concentration to the levels observed in animals at the time of heat death caused a massive increase in nervous activity. The sarcolemmal Mg (^++) activated ATPase from warm adapted crayfish was shown to be more resistant to high temperatures than that from cold adapted crayfish. This could be correlated with the greater heat resistance of the sarcolemmal Mg(^++) activated ATPase and conductivity seen in the warm adapted animals. It is proposed that the primary lesion of heat death in Astacus pallipes Lereboullet is the thermal inactivation of the sarcolemmal Mg(^++) activated ATPase which allows muscle K(^+) to move into the haemolymph. The activity of the CNS is increased markedly by the high haemolymph K(^+) resulting in loss of coordination and death. The thermal sensitivity of the Mg(^++) activated ATPase is modified by the previous thermal history of the crayfish and is involved in the mechanism of temperature adaptation

Green exercise in the workplace

New health challenges are arising in the workplace as occupations become increasingly more sedentary, and workplace stress grows. Both impact directly on health and wellbeing. Workplace interventions that are designed to improve health and wellbeing should provide coping strategies that can directly tackle stress, as well as reducing sedentary behaviours. We explore how exposure to nature can be used as a workplace intervention to reduce stress. We show how green exercise in a workplace setting may be a potentially powerful tool to tackle physical inactivity. We also discuss future research and applications of green exercise in the workplace and identify potential barriers that need to be addressed to increase its future acceptance by both employers and employees

Molecular Systematics of Rhinichthys bowersi and its Taxonomic Status

Rhinichthys bowersi is a cyprinid fish that is found mostly in tributaries of the Monongahela River. Several investigators have examined the morphology, protein polymorphism, and parasite/host relationships of R. bowersi and concluded that it is a valid species of introgressive hybrid origin while others have examined the same data and concluded that it is an F1 hybrid of R. cataractae and Nocomis micropogon. In this study, mitochondrial DNA was amplified from the 12s gene of R. bowersi and compared to that of R. cataracta, N. micropogon, and R. atratulus, an outgroup. Mitochondrial DNA differences were analyzed by Neighbor Joining (NJ), FITCH, and KITSCH algorithms. Of three individuals of R. bowersi, one clustered with R. cataractae, one clustered with N. micropogon, and another as a cyprinid outgroup. An analysis of 12s DNA sequences of three R. bowersi indicated that it was not a valid taxonomic entity, but was the result of multiple, hybrid origins