Checklist of Commelinaceae of Equatorial Guinea (Annobón,Bioko and Río Muni)

A checklist of Commelinaceae of Equatorial Guinea, comprising 46 taxa in 12 genera, is presented. The best represented genus is Palisota, with 11 species. Bibliographical references for Commelinaceae from Equatorial Guinea have been gathered and checked. Eleven species of Commelinaceae are recorded for the first time in the country. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 106–122.     

Compositional similarity among urban floras within and across continents: biogeographical consequences of human-mediated biotic interchange

Anthropogenic activities have weakened biogeographical barriers to dispersal resulting in the global spread and establishment of an increasing number of non‐native species. We examine the broad‐scale consequences of this phenomenon based on an analysis of compositional similarity across urban floras in the northeastern United States and Europe. We test the prediction that homogenization of species composition is uniquely defined within vs. between continents based on the time and place of origin of non‐native species. In this case, for archaeophytes and neophytes in Europe (introduced before and after ad 1500, respectively) and non‐native species originating from within and outside the United States. More species in urban floras were shared within than between continents. Within Europe, archaeophytes shared more species across urban floras compared with neophytes; strong associations were not observed for non‐native species across US urban floras. Between the two continents, non‐native species in the United States that originated from outside the United States shared species primarily with archaeophytes but also with European natives and neophytes. These results suggest that the direction of biotic interchange was unidirectional with species moving primarily from Europe to the United States with archaeophytes playing a primary and non‐native species originating from outside the two continents a secondary role as a homogenizing source. Archaeophytes, based on combination of biogeographical, evolutionary, and ecological factors in association with a long history of anthropogenic influence, appear to have played a prominent role in the continental and intercontinental homogenization of species composition. This suggests that the uniform homogenization of the Earth's biota is not imminent and is presently directed by a combination of biogeographically defined anthropogenic and historical factors.     

Carbon monoxide prevents hepatic mitochondrial membrane permeabilization

Background  

Low concentrations of carbon monoxide (CO) protect hepatocytes against apoptosis and confers cytoprotection in several models of liver. Mitochondria are key organelles in cell death control via their membrane permeabilization and the release of pro-apoptotic factors.     

Chromosome counts in the genus Festuca section Eskia (Poaceae) in the Iberian Peninsula

Chromosome numbers of taxa of Festuca L. section Eskia Willk. in the Iberian Peninsula are given. The levels of ploidy for five taxa are confirmed. Idiograms and karyotypic formulae of the five taxa are presented for the first time. Two levels of ploidy occur in this section: diploid and tetraploid. One taxon, Festuca elegans ssp. merinoi is tetraploid and two other taxa have diploid and tetraploid populations. The remaining two taxa are solely diploid.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 331–337.     

Greater rate of decline in maximal aerobic capacity with age in endurance-trained than in sedentary men.

To determine the relation between habitual endurance exercise status and the age-associated decline in maximal aerobic capacity [i.e., maximal O(2) consumption (Vo(2 max))] in men, we performed a well-controlled cross-sectional laboratory study on 153 healthy men aged 20-75 yr: 64 sedentary and 89 endurance trained. Vo(2 max) (ml. kg(-1). min(-1)), measured by maximal treadmill exercise, was inversely related to age in the endurance-trained (r = -0.80) and sedentary (r = -0.74) men but was higher in the endurance-trained men at any age. The rate of decline in Vo(2 max) with age (ml. kg(-1). min(-1)) was greater (P < 0.001) in the endurance-trained than in the sedentary men. Whereas the relative rate of decline in Vo(2 max) (percent decrease per decade from baseline levels in young adulthood) was similar in the two groups, the absolute rate of decline in Vo(2 max) was -5.4 and -3.9 ml. kg(-1). min(-). decade(-1) in the endurance-trained and sedentary men, respectively. Vo(2 max) declined linearly across the age range in the sedentary men but was maintained in the endurance-trained men until approximately 50 yr of age. The accelerated decline in Vo(2 max) after 50 yr of age in the endurance-trained men was related to a decline in training volume (r = 0.46, P < 0.0001) and was associated with an increase in 10-km running time (r = -0.84, P < 0.0001). We conclude that the rate of decline in maximal aerobic capacity during middle and older age is greater in endurance-trained men than in their sedentary peers and is associated with a marked decline in O(2) pulse.     

Determining the effects of habitat management and climate on the population trends of a declining steppe bird

The Little Bustard Tetrax tetrax is one of the most threatened steppe bird species in Europe, due mainly to agricultural intensification. Despite the relative importance of the Iberian population (approximately 50% of the global population) little is known about its dynamics and trends, especially in core distribution areas. This study evaluates the influences of meteorological factors and land management on the oscillations and medium-term trends of two Little Bustard populations in Central Spain. During 2001–2007, surveys of breeding male and female Little Bustards were carried out in two central Spanish locations: Valdetorres, in Special Protection Area (SPA) no. 139 (1600 ha), and Campo Real, in Important Bird Area (IBA) no. 075 (1150 ha). Densities were 3.3–4.0 and 1.1–2.1 males/km² in Campo Real, and 1.8–2.2 and 0.6–1.3 females/km² in Valdetorres. The sex ratio was biased towards males in both cases. Both populations declined during 2001–2007, especially in Valdetorres (60%). Variation in habitat composition did not explain variation in the numbers of males. Both populations were influenced by total precipitation in the preceding October–May period. Results suggest that the Little Bustard may be sensitive to future climate trends in Europe. Finally, different simulated demographic scenarios suggest that low female survival and productivity may be the immediate cause of the decline in Little Bustard populations, which is consistent with their sensitivity to climatic conditions.