Microsatellites for diversity studies in the golden hamster (Mesocricetus auratus)

Ten polymorphic microsatellites were developed for the golden hamster (Mesocricetus auratus), a widely used model organism in biological and medical researches. All loci were used to analyse the microsatellite variability in wild golden hamsters from Syria and in a sample of domestic animals comprising different strains. Average mean expected heterozygosity (H_E) and mean allele number (A) of domestic hamsters measured 0.279 ± 0.058 and 2.6 ± 0.306, respectively, compared to 0.809 ± 0.019 and 8.3 ± 1.075 found for wild hamsters. Cross‐species application in other Mesocricetus species proved conservation of most loci throughout the genus.     

Estimating the contribution of carnivorous waterbirds to nutrient loading in freshwater habitats

1. We estimated nitrogen (N) and phosphorus (P) loading into wetlands by carnivorous waterbirds with alternative physiological models using a food‐intake and an excreta‐production approach. The models were applied for non‐breeding and breeding Dutch inland carnivorous waterbird populations to quantify their contribution to nutrient loading on a landscape scale. 2. Model predictions based on food intake exceeded those based on excretion by 59–62% for N and by 2–36% for P, depending on dietary assumptions. Uncertainty analysis indicated that the intake model was most affected by errors in energy requirement, while the excretion model was dependent on faecal nutrient composition. 3. Per capita loading rate of non‐breeders increased with body mass from 0.3–0.8 g N day^?1 and 0.15 g P day^?1 in little gulls Larus minutus to 4.5–11.5 g N day^?1 and 2.1–3.2 g P day^?1 in great cormorants Phalacrocorax carbo. For breeding birds, the estimated nutrient loading by a family unit over the entire breeding period ranged between 17.6–443.0 g N and 8.6 g P for little tern Sterna albifrons to 619.6–1755.6 g N and 316.2–498.1 g P for great cormorants. 4. We distinguished between external (i.e. importing) and internal (i.e. recycling) nutrient loading by carnivorous waterbirds. For the Netherlands, average external‐loading estimates ranged between 38.1–91.5 tonnes N and 16.7–18.2 tonnes P per year, whilst internal‐loading estimates ranged between 53.1–140.5 tonnes N and 25.2–39.2 tonnes P and per year. The average contribution of breeding birds was estimated to be 17% and 32% for external and internal loading respectively. Most important species were black‐headed gull Larus ridibundus and mew gull Larus canus for external loading, and great cormorant and grey heron Ardea cinerea for internal loading. 5. On a landscape scale, loading by carnivorous waterbirds was of minor importance for freshwater habitats in the Netherlands with 0.26–0.65 kg N ha^?1 a^?1 and 0.12–0.16 kg P ha^?1 a^?1. However, on a local scale, breeding colonies may be responsible for significant P loading.     

Thigmonastic Coiling of Tendrils of Passiflora quadrangularis is Not Caused by Lateral Redistribution of Auxin

The effect of thigmotropic stimuli on the distribution of exogenously applied indoleacetic acid in intact tendrils of Passiflora quadrangularis L. has been investigated. Tips of tendrils were dipped in solutions of IAA-2-¹⁴C for 12 h and subsequently stimulated by exposure to carbon dioxide or mechanically by rubbing. The content of ¹⁴C in dorsal and ventral halves was analysed before, during and after coiling. Our experiments failed to detect any difference from the initial dorsal: ventral ratio of ¹⁴C (44:56) as a possible consequence of stimulus or of coiling. This suggests that thigmotropic curvature is not dependent on lateral movement of auxin, supporting a theory of a built-in asymmetrical reaction of the tissues to equal amounts of auxin and CO₂, respectively.     

Inflorescence Development in Chrysanthemum morifolium as a Function of Light on the Inflorescence

Covered, developing flower buds of Chrysanthemum morifoliumcv. Bright Golden Anne did not atrophy, although their dry weightwas lower than that of uncovered buds at 21, 28, 35 and 42 dafter the start of short days. This reduced dry weight was primarilydue to a reduction in the dry weight of the bracts, which arephotosynthetically active. The reduction in dry weight was notdue to a decrease in the number of bracts or florets or to alag in development of the covered buds. At 49 d the weight ofboth covered and uncovered buds was not significantly different,although the weight of the covered bracts was still reducedcompared with uncovered bracts. At 28 d uncovered buds fixedabout 40 times more ¹⁴CO₂ than covered buds. Both covered anduncovered buds had the same sink intensity and relative specificactivity, but the first bract had a greater sink intensity andrelative specific activity when covered than when uncovered,owing to photosynthesis by the bract itself. Chrysanthemum morifolium, flower development, assimilate partitioning, light, bract photosynthesis     

东喜马拉雅山地区木材腐朽菌研究2.四川青城山的木材腐朽菌

在四川青城山风景区发现木材腐朽菌60种,给出了每个木材腐朽菌的寄主和生长基质。拟黄薄孔菌Antrodia subxantha为一新种,其特点为子实体平伏,孔口表面黄色,担孢子圆柱形至窄椭圆形（3－4×1.6－2.1μm）,菌髓主要由生殖菌丝组成;该种与黄薄孔菌Antrodia xantha具有相似的孔口表面,但后者的担孢子为腊肠形（4－5×1.2－1.5μm）,且其菌髓主要有骨架菌丝组成。     

Genetic differentiation and reproductive isolation of a naturally occurring floral homeotic mutant within a wild-type population of Capsella bursa-pastoris (Brassicaceae)

Apart from the common floral architecture in Brassicaceae, variation in flower morphology occurs in several genera within the family and is considered to affect speciation processes. We analysed genetic differentiation and flowering time variation of two floral variants of Capsella bursa-pastoris , the Spe variant and the wild-type, which occur sympatrically in a vineyard in southwest Germany. The Spe variant is characterized by an additional whorl of stamens instead of petals and was formerly classified as an independent taxon ' Capsella apetala ' Opiz. Amplified fragment length polymorphism and allozyme analysis revealed a substantial genetic differentiation of the two floral variants and a higher genetic variation within the wild-type subpopulation compared with the Spe subpopulation. The low genetic variation in the mutant provided evidence of a recent local origin or recent introduction. Flowering time analysis indicated that, within the analysed population, the Spe variant flowers significantly later than the wild-type ( P  < 0.001). We conclude that the evolution and persistence of Spe within a wild-type population is facilitated by high selfing rates and been enhanced by a shift in flowering phenology. Hence, our data provide substantial evidence that the Spe phenotype has established itself as an isolated entity within a wild-type population and may thus serve as a model for the analysis of the evolutionary significance of homeotic mutants in wild populations.     

Identifying and quantifying uncertainty and spatial disagreement in the comparison of Global Land Cover for different applications

This paper provides a methodology for comparing global land cover maps that allows for differences in legend definitions between products to be taken into account. The legends of the two maps are first reconciled by creating a legend lookup table that shows how the legends map onto one another. Where there is overlap, the specific definitions for each legend class are used to calculate the degree of overlap between legend classes. In this way, one‐to‐many mappings are accounted for unlike in most methods where the legend definitions are often forced into place. Another advantage over previous map comparison methods is that application‐specific requirements are captured using expert input, whereby the user rates the importance of disagreement between different legend classes based on the needs of the application. This user‐defined matrix in conjunction with the degree of overlap between legend classes is applied on a pixel‐by‐pixel basis to create maps of spatial disagreement and uncertainty. The user can then highlight the areas of highest thematic uncertainty and disagreement between the different land cover maps allowing for areas that require further detailed examination to be readily identified. It would also be possible for several users to input their knowledge into the process, leading to a potentially more robust comparison of land cover products. The methodology of map comparison is illustrated using different land cover products including Global Land Cover 2000 (GLC‐2000) and the MODIS land cover data set. Two diverse applications are provided including the estimation of global forest cover and monitoring of agricultural land. In the case of global forest cover, an example was provided for Columbia, which showed that the MODIS land cover map overestimates forest cover in comparison with the GLC‐2000. The agricultural example, on the other hand, served to illustrate that for Sudan, MODIS tends to underestimate crop areas while GLC‐2000 overestimates them.     

Evaluation of Accuracy and Precision of Downing Population Reconstruction

ABSTRACT Downing population reconstruction uses harvest-by-age data and backward addition of cohorts to estimate minimum population size over time. Although this technique is currently being used for management of black bear (Ursus americanus) and white-tailed deer (Odocoileus virginianus) populations, it had not undergone a rigorous evaluation of accuracy. We used computer simulations to evaluate the impacts of collapsing age classes and violating the assumptions of this technique on population reconstruction estimates and trends. Changes in harvest rate or survival over time affected accuracy of reconstructed population estimates and trends. The technique was quite robust to collapsing age classes as far as 3+ for bears and deer. This method would be suitable for estimating population growth rate (λ) for populations experiencing no trend in harvest rate or natural mortality rate over time. Our evaluation showed Downing population reconstruction to be a potentially valuable tool for managing harvested species with high harvest rates and low natural mortality, with possible application to black bear and white-tailed deer populations.