18 research outputs found

    Traffic flow in a Manhattan-like urban system

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    In this paper, a cellular automaton model of vehicular traffic in Manhattan-like urban system is proposed. In this model, the origin-destination trips and traffic lights have been considered. The system exhibits three different states, i.e., moving state, saturation state and global deadlock state. With a grid coarsening method, vehicle distribution in the moving state and the saturation state has been studied. Interesting structures (e.g., windmill-like one, T-shirt-like one, Y-like one) have been revealed. A metastability of the system is observed in the transition from saturation state to global deadlock state. The effect of advanced traveller information system (ATIS), the traffic light period, and the traffic light switch strategy have also been investigated.Comment: 8 pages, 7 figure

    Physical education as Olympic education

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    Introduction In a recent paper (Parry, 1998, p. 64), I argued that the justification of PE activities lies in their capacity to facilitate the development of certain human excellences of a valued kind. Of course, the problem now lies in specifying those ‘human excellences of a valued kind’, and (for anyone) this task leads us into the area of philosophical anthropology. I suggested that the way forward for Physical Education lies in the philosophical anthropology (and the ethical ideals) of Olympism, which provide a specification of a variety of human values and excellences which: •have been attractive to human groups over an impressive span of time and space •have contributed massively to our historically developed conceptions of ourselves •have helped to develop a range of artistic and cultural conceptions that have defined Western culture. •have produced a range of physical activities that have been found universally satisfying and challenging. Although physical activities are widely considered to be pleasurable, their likelihood of gaining wide acceptance lies rather in their intrinsic value, which transcends the simply hedonic or relative good. Their ability to furnish us with pleasurable experiences depends upon our prior recognition in them of opportunities for the development and expression of valued human excellences. They are widely considered to be such opportunities for the expression of valued human excellences because, even when as local instantiations, their object is to challenge our common human propensities and abilities. I claimed that Olympic ideals may be seen not merely as inert ‘ideals’, but living ideas which have the power to remake our notions of sport in education, seeing sport not as mere physical activity but as the cultural and developmental activity of an aspiring, achieving, well-balanced, educated and ethical individual. This paper seeks to make good that claim by trying to develop a case for Physical Education as Olympic Education. I begin by setting out various accounts and conceptions of the Olympic Idea; then I suggest a unifying and organising account of the philosophical anthropology of Olympism; and this is followed by the practical application of that account in two examples of current ethical issues. Finally, I seek to present an account of Physical Education as Olympic Education

    Onchocerca volvulus transmission in the Mbam valley of Cameroon following 16 years of annual community-directed treatment with ivermectin, and the description of a new cytotype of Simulium squamosum

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    Background: The onchocerciasis focus surrounding the lower Mbam and Sanaga rivers, where Onchocerca volvulus is transmitted by Simulium damnosum s.l. (Diptera: Simuliidae), was historically the largest in the southern regions of Cameroon. Annual community-directed treatment with ivermectin (CDTI) has been taking place since 2000, but recent studies have shown that new infections are occurring in children. We aimed to investigate blackfly biting and O. volvulus transmission rates along the lower Mbam river 16 years after the formal onset of annual CDTI. Methods: Black flies were collected for three consecutive days each month between July 2016 and June 2017 at two riverside villages and two inland sites situated 4.9 km and 7.9 km from the riverside. Specimens collected at each site were dissected on one of the three collection days each month to estimate parity rates and O. volvulus infection rates, while the remaining samples were preserved for pool screening. Results: In total, 93,573 S. damnosum s.l. black flies were recorded biting humans and 9281 were dissected. Annual biting rates of up to 606,370 were estimated at the riverside, decreasing to 20,540 at 7.9 km, while, based on dissections, annual transmission potentials of up to 4488 were estimated at the riverside, decreasing to 102 and 0 at 4.9 km and 7.9 km, respectively. However, pool screening showed evidence of infection in black flies at the furthest distance from the river. Results of both methods demonstrated the percentage of infective flies to be relatively low (0.10–0.36%), but above the WHO threshold for interruption of transmission. In addition, a small number of larvae collected during the dry season revealed the presence of Simulium squamosum E. This is the first time S. squamosum E has been found east of Lake Volta in Ghana, but our material was chromosomally distinctive, and we call it S. squamosum E2. Conclusions: Relatively low O. volvulus infection rates appear to be offset by extremely high densities of biting black flies which are sustaining transmission along the banks of the lower Mbam river. Graphical Abstract: [Figure not available: see fulltext.

    Identification of the onchocerciasis vector in the Kakoi-Koda focus of the Democratic Republic of Congo

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    Background: The objective of this study was to characterise the vector in a small hyper-endemic focus of onchocerciasis (the Kakoi-Koda focus) which has recently been discovered on the western slopes of the rift valley above Lake Albert. Methodology/Principal Findings: Aquatic stages of blackflies were collected by hand from streams and rivers, and anthropophilic adult females were collected by human landing catches. Using a combination of morphotaxonomy and DNA barcoding, the blackflies collected biting humans within the focus were identified as Simulium dentulosum and Simulium vorax, which were also found breeding in local streams and rivers. Simulium damnosum s.l., Simulium neavei and Simulium albivirgulatum were not found (except for a single site in 2009 where crabs were carrying S. neavei). Anthropophilic specimens from the focus were screened for Onchocerca DNA using discriminant qualitative real-time triplex PCR. One specimen of S. vorax was positive for Onchocerca volvulus in the body, and out of 155 S. dentulosum, 30% and 11% were infected and infective (respectively). Conclusions/Significance: Simulium dentulosum currently appears to be the main vector of human onchocerciasis within the Kakoi-Koda focus, and S. vorax may be a secondary vector. It remains possible that S. neavei was the main (or only) vector in the past having now become rare as a result of the removal of tree-cover and land-use changes. Simulium vorax has previously been shown to support the development of O. volvulus in the laboratory, but this is the first time that S. dentulosum has been implicated as a probable vector of onchocerciasis, and this raises the possibility that other blackfly species which are not generally considered to be anthropophilic vectors might become vectors under suitable conditions. Because S. dentulosum is not a vector in endemic areas surrounding the Kakoi-Koda focus, it is probable that the Kakoi-Koda focus is significantly isolated

    Selenspiegel bei Glaukompatienten: eine Pilotstudie.

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    Hintergrund Spurenelemente können über oxidativen Stress vermittelte molekulare Interaktionen in die Pathogenese der Glaukomerkrankung eingreifen. Vor allem für das Spurenelement Selen (Se) wird eine Mitbeteiligung postuliert. Der Selengehalt im Serum wird unter anderem über die Ernährung gesteuert und unterliegt damit kulturellen und ethnischen Variabilitäten. Das Ziel der vorliegenden Studie war es, den Serumselenspiegel bei Patienten mit primärem Offenwinkelglaukom (pOWG) im Vergleich zu einer Kontrollgruppe zu analysieren. Diese Ergebnisse der vorliegenden deutschen Kohorte wurden auf mögliche Alters- und Gendereffekte hin untersucht sowie ins Verhältnis zu der bislang einzig beschriebenen Kohorte in den US gesetzt. Material und Methoden Die Selenkonzentration wurde von 39 Serumproben (22 pOWG, 17 Kontrollen) anhand der Inductively coupled Plasma-sector Field Mass Spectrometry (ICP-sf-MS) analysiert. Die statistische Analyse umfasste eine Kovarianz-, Perzentilenregressions-, Alters- und Genderanalyse. Ergebnisse Die Serumselenkonzentration (Ls-mean) betrug 134,86 µg/l für Patienten mit pOWG und 132,02 µg/l für die Kontrollgruppe. Der Serumselengehalt zwischen diesen beiden Gruppen zeigte keinen signifikanten Unterschied (p > 0,05). Jedoch war ein dezenter Alters- und Gendereffekt zu beobachten. Die Quantilanalyse erbrachte eine Reduktion der 1. Serumselenquantile mit ansteigendem Alter bei den Patienten mit pOWG im Gegensatz zu den Kontrollprobanden. Die Odds Ratio der 1. Quantile betrug 1,3 (jeweils in Bezug zur 2. und 3. Quantile). Zusammenfassung Der Serumselengehalt von Patienten mit pOWG zeigte sich als ca. halb so hoch wie der publizierte Wert der US-Literaturkohorte (Glaukom 209,11 ng/ml; Kontrolle 194,45 ng/ml). Zusätzlich war ein leichter Alters- und Gendereffekt zu beobachten

    Influence of atypical retardation pattern on the peripapillary retinal nerve fibre distribution assessed by scanning laser polarimetry and optical coherence tomography

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    Aim: To investigate the influence of atypical retardation pattern (ARP) on the distribution of peripapillary retinal nerve fibre layer (RNFL) thickness measured with scanning laser polarimetry in healthy individuals and to compare these results with RNFL thickness from spectral domain optical coherence tomography (OCT) in the same subjects. Methods: 120 healthy subjects were investigated in this study. All volunteers received detailed ophthalmological examination, GDx variable corneal compensation (VCC) and Spectralis-OCT. The subjects were divided into four subgroups according to their typical scan score (TSS): very typical with TSS=100, typical with 99≥TSS ≥91, less typical with 90≥TSS ≥81 and atypical with TSS ≤80. Deviations from very typical normal values were calculated for 32 sectors for each group. Results: There was a systematic variation of the RNFL thickness deviation around the optic nerve head in the atypical group for the GDxVCC results. The highest percentage deviation of about 96% appeared temporal with decreasing deviation towards the superior and inferior sectors, and nasal sectors exhibited a deviation of 30%. Percentage deviations from very typical RNFL values decreased with increasing TSS. No systematic variation could be found if the RNFL thickness deviation between different TSS-groups was compared with the OCT results. Conclusions: The ARP has a major impact on the peripapillary RNFL distribution assessed by GDx VCC; thus, the TSS should be included in the standard printout
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