Relative effects of management and environmental conditions on performance and survival of populations of a terrestrial orchid, Dactylorhiza majalis

For population viability analysis of endangered orchid populations, it is crucial to disentangle the effects of weather and management from intrinsic orchid dynamics. When doing this, typically several months’ average temperatures and/or sums of precipitations are compared with some characteristics of plant performance. Here we tested, whether short averaging intervals (1-2 weeks) are more closely correlated with orchid performance. We used 5 years of data from five Dactylorhiza majalis populations, and have shown that the improvement of prediction by shortening the interval over which the temperatures are averaged or precipitation summed, even if detectable, is only weak and not significant. This, however, may be due to low weather variability during the study. Regarding the second aspect, the effect of management (presence or absence of mowing), we have found that leaf area of D. majalis at the regularly mown site was larger than that at the sites which were mown only once in 2 years, but we did not detect a significant effect of the absence of mowing on the incidence of flowering. Mowing can affect orchid performance in two ways: by reduced shading of orchids and by reducing competition with other species. Therefore, we have determined the co-occurring species associated with presence or absence of mowing and found that shading significantly affected the length of the flower stalk, the ratio of leaf width to leaf length at the end of the season, but did not affect seed weight and probability of flowering the next year. We conclude that the most appropriate management for D. majalis is mowing at least once a year, ideally at the end of June/beginning of July, after its fruiting.     

Diagnostics of hydromorphism in soils of autonomous positions on the Severo-Sos’vinsk Upland (Western Siberia)

The complex studies of hydromorphism features in taiga weakly differentiated soils using morphological (color), chemical (iron content in different extracts, indicators of reducing conditions (IRIS)), and geobotanic (using the Ramenskii scale) methods have led to ambiguous conclusions. In all the soils, surface gleying was manifested. According to the results obtained by different methods, the maximum reduction processes were related to either the sublitter or the next deeper horizon. The Schwertmann coefficient, the criterion of Bodegom, and the Ramenskii scale indicated an increase of hydromorphism in the soils studied in the following sequence: the lower part of the ridge slopes drained by the small gullies < the middle part of the slopes < the flat tops of the ridges < the depression between the ridges. The morphological diagnostics of gleying proved to be a less sensitive method, which can recognize only the most contrasting hydromorphic soils. The lower horizons in some taiga soils have a bluish gray color probably not related to the recent soil hydromorphism.     

Losing a staging area: Eastward redistribution of Afro-Eurasian ruffs is associated with deteriorating fuelling conditions along the western flyway

The fuelling performance of long-distance migrants at staging areas indicates local conditions and determines the viability of migration routes. Here we present a first case study where long-term fuelling performance was documented along two migration routes with differential population trends. Ruffs (Philomachus pugnax) are shorebirds of inland freshwater wetlands that migrate from the sub-Saharan wintering grounds, via Europe, to the northern Eurasian breeding grounds. Assessments from 2001 to 2008 of fuelling during northward migration at the major western and eastern staging site revealed that daily mass gain rates steeply declined across years in the grasslands for dairy production in Friesland, The Netherlands, and remained constant in the Pripyat floodplains in Belarus, 1500 km further east. Migrants in Friesland decreased from 2001 to 2010 by 66%, amounting to a loss of 21,000 individuals when counts were adjusted for length of stay as determined by resightings. In the same period numbers in Pripyat increased by 12,000. Ruffs individually ringed in Friesland were resighted in subsequent springs at increasingly eastern sites including Pripyat. Our results corroborate published evidence for an eastward redistribution of Arctic breeding ruffs and suggest that the decreasing fuelling rates in the westernmost staging area contribute to this redistribution. The shift implies that responses occur within a single generation. The hypothesis that the choice of route during northward migration may be driven by food availability can now be tested by creating greater areas of wet grasslands in Friesland. When local staging conditions improve we predict that ruffs will make the reverse shift.     

Evaporation of impurity ions from solutions into the air

A mechanism is proposed for low-temperature transfer of impurity ions from electrolyte solutions into air taking into account the physico-chemical structure of the liquid and its surface, as well as meteorological factors. The model adequately describes the experimental data obtained by the present authors, and Azad and Latham (1967). The recommendations on concentration limits for some industrial impurities in sewage are given.     

Asynchronous climate changes in the North Atlantic and Japan during the last termination

Pollen records from the annually laminated sediment sequence in Lake Suigetsu, Japan, suggest a sequence of climate changes during the Last Termination that resembles that of the North Atlantic region but with noticeable differences in timing. An interstadial interval commenced a few centuries earlier [approximately 15,000 years before the present (yr B.P.)] than the North Atlantic GI-1 (B?lling) event. Conversely, the onset of a Younger Dryas (YD)-like cold reversal (12,300 to 11,250 yr B.P.) postdated the North Atlantic GS-1 (YD) event by a few centuries. Climate in the Far East during the Last Termination reflected solar insolation changes as much as Atlantic influences.     

Sperm quality in male <Emphasis Type="Italic">Barbus barbus</Emphasis> L. fed different diets during the spawning season

Sperm quality of Barbus barbus L. was compared among the three following dietary regimes: Group A, fed 100% commercial diet (Karpico™ containing 33% crude protein and 6% fat), Group B, fed 78% commercial diet and 22% frozen chironomid (Chironomus plumosus) larvae, and Group C, fed 56% commercial diet and 44% frozen chironomid larvae. Concentrations of polyunsaturated fatty acids (PUFAs) in Group A, B, and C were 39.1, 42.0, and 44.6, respectively, as a percentage of total fatty acids. Sperm morphology, volume, concentration and motility, total number of spermatozoa, and osmolality of the seminal plasma were compared during the spawning season. Dietary regime did not influence sperm volume, concentration, or total number of spermatozoa, osmolality of seminal plasma, or the percentage of motile sperm, but significantly affected sperm morphology (except for anterior and posterior parts of the midpiece) and sperm velocity (P < 0.05). Groups B and C showed similar sperm characteristics during the spawning season compared to Group A. Almost all parameters changed either among or within groups during the spawning season, suggesting differences in terms of the optimal time for sperm collection. The best time for sperm collection was March for Group A, but April for Groups B and C, when the osmolality of the seminal plasma measured 289 mOsmol kg⁻¹ and sperm motility was maximal. Spermatogenesis, hydration, and cell decomposition were confirmed as the three major parameters controlling sperm characteristics during the spawning season. The possible correlation between sperm morphology and motility requires further study.     

Basis for structural diversity in homologous RNAs

Large RNA molecules, such as ribozymes, fold with well-defined tertiary structures that are important for their activity. There are many instances of ribozymes with identical function but differences in their secondary structures, suggesting alternative tertiary folds. Here, we report a crystal structure of the 161-nucleotide specificity domain of an A-type ribonuclease P that differs in secondary and tertiary structure from the specificity domain of a B-type molecule. Despite the differences, the cores of the domains have similar three-dimensional structure. Remarkably, the similar geometry of the cores is stabilized by a different set of interactions involving distinct auxiliary elements.     

Kurilosides A1, A2, C1, D,E and F—Triterpene Glycosides from the Far Eastern Sea Cucumber Thyonidium (= Duasmodactyla) kurilensis (Levin): Structures with Unusual Non-Holostane Aglycones and Cytotoxicities

Six new monosulfated triterpene tetra-, penta- and hexaosides, namely, the kurilosides A₁ (1), A₂ (2), C₁ (3), D (4), E (5) and F (6), as well as the known earlier kuriloside A (7), having unusual non-holostane aglycones without lactone, have been isolated from the sea cucumber Thyonidium (= Duasmodactyla) kurilensis (Levin) (Cucumariidae, Dendrochirotida), collected in the Sea of Okhotsk near Onekotan Island from a depth of 100 m. Structures of the glycosides were established by 2D NMR spectroscopy and HR-ESI mass spectrometry. Kurilosides of the groups A and E contain carbohydrate moieties with a rare architecture (a pentasaccharide branched by C(4) Xyl1), differing from each other in the second monosaccharide residue (quinovose or glucose, correspondingly); kurilosides of the group C are characterized by a unique tetrasaccharide branched by a C(4) Xyl1 sugar chain; and kurilosides of the groups D and F are hexaosides differing from each other in the presence of an O-methyl group in the fourth (terminal) sugar unit. All these glycosides contain a sulfate group at C-6 of the glucose residue attached to C-4 Xyl1 and the non-holostane aglycones have a 9(11) double bond and lack γ-lactone. The cytotoxic activities of compounds 1–7 against mouse neuroblastoma Neuro 2a, normal epithelial JB-6 cells and erythrocytes were studied. Kuriloside A₁ (1) was the most active compound in the series, demonstrating strong cytotoxicity against the erythrocytes and JB-6 cells and a moderate effect against Neuro 2a cells.