Phylogeography and evolutionary history of Leopoldamys neilli, a Murinae rodent endemic to limestone karsts, in Thailand

Conference (2012, May 15)

Limestone karsts are highly threatened biodiversity hotspots supporting high levels of endemic species. Karsts are patchy distributed within Southeast Asia and their isolation from one another give them ... [more ▼]

Limestone karsts are highly threatened biodiversity hotspots supporting high levels of endemic species. Karsts are patchy distributed within Southeast Asia and their isolation from one another give them the features of “islands on the continent” and has important consequences for the genetic structure of endemic taxa. In present study, we have studied the phylogeography of Neill’s Rat Leopoldamys neilli, a threatened Murinae rodent species endemic to limestone karsts of Thailand, on the basis of two mitochondrial markers, two nuclear fragments, as well as twelve microsatellite loci. Our study gave evidence of a complex and strong geographic structure of the genetic diversity for L. neilli. Several highly differentiated genetic lineages were observed throughout Thailand. These results suggest a severe fragmentation of L. neilli’s populations, correlated to the fragmented distribution of its habitat and highlight its high endemicity to limestone karsts. The evolutionary history of L. neilli was investigated using Approximate Bayesian computation (ABC) and our results suggest that the current phylogeographic pattern of this species result from several deep vicariant events during Plio-Pleistocene. To conclude, this study revealed an unexpected high level of intraspecific diversity within L. neilli. These results consolidate the importance to strengthen the protection of limestone habitats and to preserve not only their high interspecific but also intraspecific diversity. [less ▲]

Phylogeography of a nematode (Heligmosomoides polygyrus) in the western Palearctic region: persistence of northern cryptic populations during ice ages?

in Molecular Ecology (2005), 14(3), 765-79

This study establishes the continental phylogeographical pattern of a European nematode, Heligmosomoides polygyrus (Dujardin, 1845; Heligmosomoidea). We sequenced 687 base pairs of the mitochondrial DNA ... [more ▼]

This study establishes the continental phylogeographical pattern of a European nematode, Heligmosomoides polygyrus (Dujardin, 1845; Heligmosomoidea). We sequenced 687 base pairs of the mitochondrial DNA (mtDNA) cyt b gene for 136 individuals collected in 22 localities. The results revealed that H. polygyrus populations are separated into five major units corresponding to the Italian, northern European (Denmark and Ireland), Iberian, western European, and Balkan populations. Different subclades were also observed within the first two groups. Based on the rate of molecular evolution of H. polygyrus cyt b gene-estimated to 3.5%-3.7% divergence per million years (Myr) in a previous study--the isolation time of the five clades was estimated between 2.5 +/- 0.24 and 1.5 +/- 0.23 million years ago. Moreover, H. polygyrus presents a higher genetic variability in the Mediterranean peninsulas as compared to northwestern Europe, highlighting the role of these regions as refuge areas. Like its specific host, the wood mouse Apodemus sylvaticus, H. polygyrus' pattern of postglacial recolonization of northwestern Europe was initiated from Iberian populations, while Italian and Balkan populations did not expand to the north. The results also suggest the existence of forested and temperate refuges in the southern British Isles during the Quaternary. Finally, the genetic diversity as well as the level of genetic divergence between the lineages of H. polygyrus are compared to those observed in other vertebrate and invertebrate phylogeographical studies: the existence of highly differentiated lineages in H. polygyrus (5%-10% of genetic divergence) highlights that the effects of Pleistocene climate changes on free-living organisms are also reflected in their obligate parasites. [less ▲]

Phylogeography of the garden dormouse Eliomys quercinus in the western Palearctic region

in Journal of Mammalogy (2012), 93(6),

The garden dormouse, Eliomys quercinus (Rodentia, Gliridae), displays a surprisingly high karyotypic diversity, with the number of chromosomes varying between 2N ¼ 48 and 2N ¼ 54. We aimed to assess ... [more ▼]

The garden dormouse, Eliomys quercinus (Rodentia, Gliridae), displays a surprisingly high karyotypic diversity, with the number of chromosomes varying between 2N ¼ 48 and 2N ¼ 54. We aimed to assess whether the karyotypic diversity is congruent with the mitochondrial differentiation of the populations; improve our understanding of the taxonomic relationships between garden dormouse populations based on both chromosomal and mitochondrial information; and establish the phylogeographic history of the species and the time of differentiation of mitochondrial lineages of E. quercinus and E. melanurus. For this purpose we sequenced the mitochondrial cytochrome-b (Cytb) gene for 62 E. quercinus and 4 E. melanurus from 27 localities representing all the known chromosomal races of the genus Eliomys in the western Palearctic region. Our results 1st showed that populations of E. quercinus are separated into 4 evolutionarily significant units partially congruent with the chromosomal races and corresponding to Iberian (2N¼48), Italian (2N¼48 or 50), western European (2N¼48, 49, or 50), and Alpine (2N ¼ 52 or 54) mitochondrial lineages or clades. The existence of hybrid individuals between chromosomal races and the presence of several chromosomal races within each mitochondrial lineage both indicate that gene flow persists between chromosomal races. Second, we estimated that the major mitochondrial lineages differentiated from each other around 4.2 6 SD 1 million years ago, thus predating the Quaternary glaciations. Third, E. quercinus displayed a higher haplotypic variability in the Mediterranean peninsula than in the northwestern European populations. However, E. quercinus did not show a pattern of ostglacial recolonization of northwestern Europe from Iberian or Italian populations. Our results also suggest that additional, unexpected refuge regions around the Alps exist for the species. Such information will be useful for deciphering the priorities for the protection of E. quercinus, which is listed as ‘‘Near Threatened’’ on the International Union for the Conservation of Nature Red List of Threatened Species and is protected by Appendix III of the Bern Convention. [less ▲]

Physical activity patterns of children after neonatal arterial switch operation.

in Annals of Thoracic Surgery (2006), 81(2), 665-70

BACKGROUND: Physical inactivity is a major atherosclerosis risk factor. The exercise tolerance is usually excellent after neonatal arterial switch operation, but those patients in whom coronary anomalies ... [more ▼]

BACKGROUND: Physical inactivity is a major atherosclerosis risk factor. The exercise tolerance is usually excellent after neonatal arterial switch operation, but those patients in whom coronary anomalies remain the main late complication, risk developing atherosclerotic coronary disease owing to perceived physical activity restrictions. METHODS: We investigated physical activity patterns of 52 unselected children 7 to 14 years after neonatal arterial switch operation for transposition of the great arteries by 24-hour continuous heart rate monitoring. The percentage of heart rate reserve was used to measure the amounts of activities. Comparisons were made with 35 children with repaired atrial or ventricular septal defect and with 127 age-matched healthy children. RESULTS: Children after arterial switch operation accumulated 167.3 +/- 70.6, 25.3 +/- 12.9, and 15.7 +/- 11.3 minutes a day (mean +/- SD) of light, moderate, and vigorous physical activities, respectively. At the same activity levels, children with repaired septal defect accumulated 165.2 +/- 82.2, 26.2 +/- 11.7, and 16.2 +/- 9.1 minutes a day, and their healthy peers 164.8 +/- 74.5, 31.8 +/- 13.9, and 21.9 +/- 11.3 minutes a day. Both cardiac groups were significantly less active than the control group when considering moderate (p = 0.026) and vigorous activities (p = 0.006). Only 19% and 27% of the children after arterial switch operation engaged, respectively, in more than 30 minutes a day of moderate activity and 20 minutes a day of vigorous activity. CONCLUSIONS: Children after arterial switch operation, just like other cardiac children, do not meet the guidelines for physical activity. We should encourage regular physical activity to offset adult sedentary behavior and to prevent atherosclerotic cardiovascular disease in those patients whose long-term function of the coronary arteries remains a matter of concern. [less ▲]

Physical activity, obesity, and cardiovascular risk factors in children. The Belgian Luxembourg Child Study II.

in Obesity Research (1997), 5(6), 549-56

Physical activity was measured in relation to cardiovascular (CV) risk factors in a randomly selected population of 1028 children from Province de Luxembourg in Belgium, a mainly rural area with a high ... [more ▼]

Physical activity was measured in relation to cardiovascular (CV) risk factors in a randomly selected population of 1028 children from Province de Luxembourg in Belgium, a mainly rural area with a high prevalence of such risk factors among adults and children. Physical activity was estimated as participation in sport activities, a major indicator of leisure-time physical activity in schoolchildren, and physical inactivity was estimated as frequency and duration of television (TV) watching. Boys participated more frequently in sport activities than girls did (p = 0.001). A majority of the children watched TV daily. After age adjustment, bodyweight (girls, p < 0.012; boys, p < 0.027) and, in boys, body mass index (BMI) (p < 0.039) were related to days per week of TV watching. No significant relationships with other CV risk factors remained after adjustments for BMI. In analyses of independent contributions of age, TV watching, and sports activity on CV risk factors, age showed highly significant relationships. In boys, TV showed relationships with BMI (p < 0.04) and (borderline) with systolic blood pressure, independent of age and sports activity, whereas the latter was significantly related to subscapular skinfold (p < 0.04) and (borderline) with triceps skinfold and cholesterol. In girls, no significant independent contributions to risk factor associations were found. The father's education was directly associated with sports activities, whereas the mother being a housewife showed negative relationships to physical activity and positive to TV watching in their children, suggesting socioeconomic influence on the activity patterns of children. Furthermore, registrations suggested less physical activity in the most rural part of the area. It is concluded that children in this mainly rural area watch TV frequently. In boys, physical inactivity, measured both as TV watching and as registrations of sports activities, contributes independently to body fat mass. In girls, no contribution or weaker contributions of physical inactivity were found. This suggests that contributory factors leading to obesity might be different in girls and boys. [less ▲]

Physical and chemical properties of pyropheophorbide)a-methyl ester in ethanol, phosphate buffer and aqueous dispersion of small unilamellar dimyristoyl-L-a-phosphatidylcholine vesicles

in Photochemical & Photobiological Sciences (2006), 5

The aggregation process of pyropheophorbide-a methyl ester (PPME), a second generation hotosensitizer, was investigated in various solvents. Absorption and fluorescence spectra showed that the ... [more ▼]

The aggregation process of pyropheophorbide-a methyl ester (PPME), a second generation hotosensitizer, was investigated in various solvents. Absorption and fluorescence spectra showed that the photosensitizer was under a monomeric form in ethanol as well as in dimyristoyl-L-α-phosphatidylcholine liposomes while it was strongly aggregated in phosphate buffer. A quantitative determination of reactive oxygen species production by PPME in these solvents has been undertaken by electron spin resonance associated with spin trapping technique and absorption spectroscopy. In phosphate buffer, both electron spin resonance and absorption measurements led to the conclusion that singlet oxygen production was not detectable while hydroxyl radical production was very weak. In liposomes and ethanol, singlet oxygen and hydroxyl radical production increased highly; the singlet oxygen quantum yield was determined to be 0.2 in ethanol and 0.13 in liposomes. The hydroxyl radical production origin was also investigated. Singlet oxygen was formed from PPME triplet state deactivation in presence of oxygen. Indeed, the triplet state formation quantum yield of PPME was found to be about 0.23 in ethanol, 0.15 in liposomes (too small to be measured in PBS). [less ▲]

Physical and numerical modeling of overbank flow with a groyne on the floodplain

in River Flow 2008: 4th Int. Conf. on Fluvial Hydraulics (2008)

Physical and textural characteristics of hydrogenated low-erucic acid rapeseed oil and low-erucic acid rapeseed oil blends

in Journal of the American Oil Chemists' Society [=JAOCS] (2003), 80(2), 109-114

Low-erucic acid rapeseed oil (LERO) and hydrogenated low-erucic acid rapeseed oil (HLERO) were blended in binary systems. The blends were then studied for their physical properties such as solid fat ... [more ▼]

Low-erucic acid rapeseed oil (LERO) and hydrogenated low-erucic acid rapeseed oil (HLERO) were blended in binary systems. The blends were then studied for their physical properties such as solid fat content, melting curves by DSC, textural properties, and polymorphism. Phase behavior diagrams were constructed from the DSC and X-ray results, and isosolid diagrams were constructed from the NMR results. The mixture of HLERO and LERO displayed a monotectic behavior for all the storage time at 15degreesC. The aim of this work was to evaluate physical characteristics of binary blends of HLERO and nonhydrogenated LERO in order to use only LERO and hardened LERO in bakery shortenings. The mixture of 60% HLERO and 40% LERO is suitable to use as a plastic shortening, This blend is beta tending upon storage at 15degreesC. It could be used in pie crust applications. [less ▲]

The physical chemistry of comets

in Popular Astronomy (1943), 51

Physical education teachers as physical activity promoters: Examples of initial/continuous preparation processes

Conference (2010, November)

Literature emphasizes the increasing prevalence of obesity. This phenomenon is related to growing health problems and to their cost for the society in terms of health expenses as well as lack of human ... [more ▼]

Literature emphasizes the increasing prevalence of obesity. This phenomenon is related to growing health problems and to their cost for the society in terms of health expenses as well as lack of human well-being. Sedentary lifestyle is systematically pointed out as one of the determining factors at the origin of this situation. WHO (2001) underlined the need of a multifactorial action while Pate et al. (2006) highlighted the school’s central role. Within the school, it seems that the physical education (PE) teacher represents the corner stone of any process aiming to promote physical activity (PA) (USDHHS, 1996; Tappe & Burgeson, 2004). Nevertheless, when determining if PE teachers are ready to be the expected PA promoters, it appears that, in Wallonia (as it could be the case in other countries), several data show that the answer is not really positive. It seems that PE teachers need some support in order to make youths physically active, and adopting a healthy lifestyle. In fact, proposing traditional lessons focusing on sport would not be sufficient to reach these objectives. In this way, PE teacher educators should have two priorities: (1) to clarify the PE teachers’ representations of PA and (2) to identify and share strategies aiming to define their potential actions on the field. The presentation illustrated four approaches that were experimented at the University of Liege in pre- and in-service PE teacher education. The major goal of the speech was to involve the participants by stimulating reflexibility and content development. Four questions have been in the centre of the activity: (1) What is physical Activity? (2) What must be done, finally? (3) How to deal with arguments against practice? (4) What could do PE teachers to promote an active lifestyle? Each question was discussed through distinct approaches that could be used by the participants in their own practice. [less ▲]