174 research outputs found
The impact of a school-based water supply and treatment, hygiene, and sanitation programme on pupil diarrhoea: a cluster-randomized trial.
The impact of improved water, sanitation, and hygiene (WASH) access on mitigating illness is well documented, although impact of school-based WASH on school-aged children has not been rigorously explored. We conducted a cluster-randomized trial in Nyanza Province, Kenya to assess the impact of a school-based WASH intervention on diarrhoeal disease in primary-school pupils. Two study populations were used: schools with a nearby dry season water source and those without. Pupils attending 'water-available' schools that received hygiene promotion and water treatment (HP&WT) and sanitation improvements showed no difference in period prevalence or duration of illness compared to pupils attending control schools. Those pupils in schools that received only the HP&WT showed similar results. Pupils in 'water-scarce' schools that received a water-supply improvement, HP&WT and sanitation showed a reduction in diarrhoea incidence and days of illness. Our study revealed mixed results on the impact of improvements to school WASH improvements on pupil diarrhoea
Opacity Issues in Games with Imperfect Information
We study in depth the class of games with opacity condition, which are
two-player games with imperfect information in which one of the players only
has imperfect information, and where the winning condition relies on the
information he has along the play. Those games are relevant for security
aspects of computing systems: a play is opaque whenever the player who has
imperfect information never "knows" for sure that the current position is one
of the distinguished "secret" positions. We study the problems of deciding the
existence of a winning strategy for each player, and we call them the
opacity-violate problem and the opacity-guarantee problem. Focusing on the
player with perfect information is new in the field of games with
imperfect-information because when considering classical winning conditions it
amounts to solving the underlying perfect-information game. We establish the
EXPTIME-completeness of both above-mentioned problems, showing that our winning
condition brings a gap of complexity for the player with perfect information,
and we exhibit the relevant opacity-verify problem, which noticeably
generalizes approaches considered in the literature for opacity analysis in
discrete-event systems. In the case of blindfold games, this problem relates to
the two initial ones, yielding the determinacy of blindfold games with opacity
condition and the PSPACE-completeness of the three problems.Comment: In Proceedings GandALF 2011, arXiv:1106.081
Fault-tolerant Cooperative Tasking for Multi-agent Systems
A natural way for cooperative tasking in multi-agent systems is through a
top-down design by decomposing a global task into sub-tasks for each individual
agent such that the accomplishments of these sub-tasks will guarantee the
achievement of the global task. In our previous works [1], [2] we presented
necessary and sufficient conditions on the decomposability of a global task
automaton between cooperative agents. As a follow-up work, this paper deals
with the robustness issues of the proposed top-down design approach with
respect to event failures in the multi-agent systems. The main concern under
event failure is whether a previously decomposable task can still be achieved
collectively by the agents, and if not, we would like to investigate that under
what conditions the global task could be robustly accomplished. This is
actually the fault-tolerance issue of the top-down design, and the results
provide designers with hints on which events are fragile with respect to
failures, and whether redundancies are needed. The main objective of this paper
is to identify necessary and sufficient conditions on failed events under which
a decomposable global task can still be achieved successfully. For such a
purpose, a notion called passivity is introduced to characterize the type of
event failures. The passivity is found to reflect the redundancy of
communication links over shared events, based on which necessary and sufficient
conditions for the reliability of cooperative tasking under event failures are
derived, followed by illustrative examples and remarks for the derived
conditions.Comment: Preprint, Submitted for publicatio
Aquaporins: relevance to cerebrospinal fluid physiology and therapeutic potential in hydrocephalus
The discovery of a family of membrane water channel proteins called aquaporins, and the finding that aquaporin 1 was located in the choroid plexus, has prompted interest in the role of aquaporins in cerebrospinal fluid (CSF) production and consequently hydrocephalus. While the role of aquaporin 1 in choroidal CSF production has been demonstrated, the relevance of aquaporin 1 to the pathophysiology of hydrocephalus remains debated. This has been further hampered by the lack of a non-toxic specific pharmacological blocking agent for aquaporin 1. In recent times aquaporin 4, the most abundant aquaporin within the brain itself, which has also been shown to have a role in brain water physiology and relevance to brain oedema in trauma and tumours, has become an alternative focus of attention for hydrocephalus research. This review summarises current knowledge and concepts in relation to aquaporins, specifically aquaporin 1 and 4, and hydrocephalus. It also examines the relevance of aquaporins as potential therapeutic targets in hydrocephalus and other CSF circulation disorders
Investigating the environmental Kuznets curve hypothesis: the role of tourism and ecological footprint
The main objective of this study is to examine the environmental Kuznets curve (EKC) hypothesis by utilizing the ecological footprint as an environment indicator and GDP from tourism as the economic indicator. To achieve this goal, an environmental degradation model is established during the period of 1988–2008 for 144 countries. The results from the time series generalized method of moments (GMM) and the system panel GMM revealed that the number of countries that have a negative relationship between the ecological footprint and its determinants (GDP growth from tourism, energy consumption, trade openness, and urbanization) is more existent in the upper middle- and high-income countries. Moreover, the EKC hypothesis is more present in the upper middle- and high-income countries than the other income countries. From the outcome of this research, a number of policy recommendations were provided for the investigated countries
Isolation of proteins related to the Rh polypeptides from nonhuman erythrocytes.
It is thought that the Rh antigens may be important in maintaining normal erythrocyte membrane integrity. Despite their name, Rh antigens are serologically present only on human erythrocytes. Rh structural polymorphisms are known to reside within a family of nonglycosylated Mr 32,000 integral membrane proteins that can be purified by hydroxylapatite chromatography. Mr 32,000 integral membrane proteins were purified similarly from erythrocyte membrane vesicles prepared from rhesus monkeys, cows, cats, and rats, but could not be purified from human Rhmod erythrocytes, a rare syndrome lacking Rh antigens. The purified Mr 32,000 polypeptides were labeled with 125I, digested with chymotrypsin, and found to be 30-60% identical to human Rh polypeptides when compared by two-dimensional iodopeptide mapping. The physiologic function of the Rh polypeptides remains to be identified; however, the existence of related proteins in nonhuman erythrocytes supports the concept that the Rh polypeptides are erythrocyte membrane components of fundamental significance
Polymorphism in the Mr 32,000 Rh protein purified from Rh(D)-positive and -negative erythrocytes.
A Mr 32,000 integral membrane protein has previously been identified on erythrocytes bearing the Rh(D) antigen and is thought to contain the antigenic variations responsible for the different Rh phenotypes. To study it on a biochemical level, a simple large-scale method was developed to purify the Mr 32,000 Rh protein from multiple units of Rh(D)-positive and -negative blood. Erythrocyte membrane vesicles were solubilized in NaDodSO4, and a tracer of immunoprecipitated 125I surface-labeled Rh protein was added. The Rh protein was purified to homogeneity by hydroxylapatite chromatography followed by preparative NaDodSO4/PAGE. Approximately 25 nmol of pure Rh protein was recovered from each unit of Rh(D)-positive and -negative blood. Rh protein purified from both Rh phenotypes appeared similar by one-dimensional NaDodSO4/PAGE, and the N-terminal amino acid sequences for the first 20 residues were identical. Rh proteins purified from Rh(D)-positive and -negative blood were compared by two-dimensional iodopeptide mapping after 125I-labeling and alpha-chymotrypsin digestion. The peptide maps were very similar; however, at least two additional iodopeptides were consistently noted in the Rh proteins purified from Rh(D)-positive erythrocytes. These data indicate that a similar core Rh protein (or group of related proteins) exists in both Rh(D)-positive and -negative erythrocytes, and the Rh proteins from erythrocytes with different Rh phenotypes contain distinct structural polymorphisms
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