Microgeographical variation in brown trout reproductive traits: possible effects of biotic interactions

This study documents substantial variation in reproductive traits among populations of stream-dwelling brown trout ( Salmo trutta L.) at a very small geographic scale. Within two streams, we found a parallel pattern of variation, where females living above major waterfalls produced fewer and larger eggs than conspecifics from below the waterfalls. Four additional streams were represented with either a below-waterfall site ( n =2) or an above-waterfall site ( n =2). When these streams were included in the analyses, there was no consistent difference in reproductive traits between females from above- and below-waterfall sites. There was no significant difference in total reproductive investment among sites within streams, but considerable variation among streams. Female first-year growth rates was estimated from scales, and differed significantly among populations. Within streams, females from below waterfalls experienced higher first-year growth rates as compared to females from above the waterfalls. Within seven out of eight populations, egg size increased significantly with increasing female body length. Within three populations, we found evidence for a trade-off between offspring size and offspring number, as a negative association between fecundity and egg size independently of adult body size. Within three populations egg size decreased significantly with increasing maternal first-year growth, independently of adult body size. We suggest that the within-stream differences in offspring size/number strategies are influenced by population density and growth effects. Earlier, we have shown that population densities are consistently lower below the waterfalls in these streams. The Alpine bullhead ( Cottus poecilopus ) is found only below the waterfalls and could influence brown trout demography.     

A life-history perspective on strategic mating effort in male scorpionflies

In species with high male mating effort, there is a trade-offbetween mating effort spent in a current mating and resourcesleft for future matings. Consequently, to maximize their reproductivesuccess, males have to invest strategically, saving resourcesin matings with low reproductive gain for future, more valuablematings. However, as males age, the expected future reproductivesuccess constantly declines. Thus, the importance of resource rationing may drastically change during a lifetime. Males ofthe scorpionfly Panorpa cognata offer females a costly nuptialgift before copulation, which functions as male mating effort.Resources for the production of these salivary masses are severelylimited for males in poor condition. We found that males investedmore in copulations with high-quality females than in copulationswith low-quality females. However, males ceased to discriminateas they became older. Old males, with a relative small numberof expected future matings, did not invest differentially incopulations with high- versus low-quality females. In copulationswith low-quality females, males invested more in late thanin initial matings, whereas in matings with high-quality females,time of mating had no influence on mating effort. These resultsimply that males adaptively change their resource allocationstrategy during the course of the season. Initial matings seemto be characterized by male prudence; in later matings, malesseem to adopt a more opportunistic mating strategy.     

Preparation of hydrolysates from tobacco stalks and ethanolic fermentation by Saccharomyces cerevisiae

Chipped tobacco stalks were subjected to steam pretreatment at 205 °C for either 5 or 10 min before enzymatic hydrolysis. Glucose (15.4–17.1 g/l) and xylose (4.5–5.0 g/l) were the most abundant monosaccharides in the hydrolysates. Mannose, galactose and arabinose were also detected. The hydrolysate produced by pretreatment for 10 min contained higher levels of all sugars than the 5 min-pretreated hydrolysate. The amounts of inhibitory compounds found in the hydrolysates were relatively low and increased with increasing pretreatment time. The hydrolysates were fermented with baker's yeast. Ethanol yield, maximum volumetric productivity and specific productivity were used as criteria of fermentability of the hydrolysates. The fermentation of the hydrolysates was only slightly inhibited compared to reference solutions having a similar composition of fermentable sugars. The ethanol yield in the hydrolysates was 0.38–0.39 g/g of initial fermentable sugars, whereas it was 0.42 g/g in the reference. The biomass yield was twofold lower in the hydrolysates than in the reference. The fermentation inhibition caused by the tobacco stalk hydrolysates was less than that caused by sugarcane bagasse hydrolysates obtained under the same hydrolysis conditions.     

High occurrence of red-listed bryophytes and lichens in mature managed forests in boreal Sweden

Successful biodiversity conservation needs to be based on reliable data regarding the distribution and abundance of species. Red Lists summarize the status of rare and declining species. Here we present the first detailed survey (10 m × 10 m resolution) of nationally red-listed bryophytes and lichens at stand level in boreal forests. 30 managed forest production stands in boreal Sweden, soon to be harvested, were surveyed in detail regarding red-listed bryophytes and lichens. On the 180 ha totally investigated, 33 red-listed species were found, representing 35% of all forest red-listed bryophytes and lichens so far recorded from this part of Sweden. The mean number of red-listed species per stand was 10 and varied between 5 and 16. Excluding three species which were so common that, given the time-limit, it was not possible to record all of their occurrences, there were on average 6 number of observations ha⁻¹. The presence and density exceed those earlier found in ‘key habitats’, defined as hot-spots for red-listed species. Almost all observations were made on trees, with 48% on living trees and 52% on dead. Altitude, area and stem volume explained 67% of the red-list species density. The results highlight the importance of unprotected areas for rare and declining species and point to a hitherto unacknowledged high biodiversity value of mature managed boreal forest stands, shaped by a less intense forestry than today's. It also raises questions regarding the use of red-listed species to identify areas of importance to biodiversity. Objective and systematic surveys of red-listed species in the forest landscape, including younger stands, are urgent.Der erfolgreiche Schutz der Biodiversität muss auf verlässlichen Daten über die Verbreitung und Abundanz der Arten basieren. Rote Listen fassen den Status seltener und abnehmender Arten zusammen. Hier präsentieren wir die erste detaillierte Erfassung (10 m × 10 m Auflösung) von Bryophyten und Flechten der nationalen Rote Liste auf Bestandsniveau in borealen Wäldern. Im borealen Schweden wurden in 30 bewirtschafteten Produktionswälder, die bald geerntet werden sollen, die Bryophyten und Flechten der Roten Liste im Detail erfasst. Auf den insgesamt untersuchten 180 ha wurden 33 Arten der Roten Liste gefunden, die 35% aller Wald-Bryophyten und-Flechten der Roten Liste repräsentieren, die bisher in diesem Teil Schwedens erfasst wurden. Die mittlere Anzahl derRote-Liste-Arten pro Bestand war 10 und variierte zwischen 5 und 16. Unter Ausschluss von drei Arten, die so gewöhnlich waren, dass es bei dem gegebenen Zeitlimit nicht möglich war alle ihre Vorkommen zu erfassen, gab es im Durchschnitt 6 Beobachtungen ha⁻¹. Vorkommen und Dichten übertrafen die früher in “Schlüsselhabitaten” gefundenen, die als ‘hot spots’ bezeichnet werden. Fast alle Beobachtungen wurden auf Bäumen gemacht, mit 48% auf lebenden und 52% auf toten Bäumen. Die Höhe, das Gebiet und das Stammvolumen erklärten 67% der Dichte der Rote-Liste-Arten. Die Ergebnisse heben die Wichtigkeit nicht-geschützter Gebiete für seltene und abnehmende Arten hervor und weisen auf einen bisher nicht wahrgenommenen hohen Biodiversitätswert von alten bewirtschafteten borealen Waldbeständen hin, die von einer weniger intensiven Forstwirtschaft als der heutigen geformt wurden. Es stellen sich ebenso Fragen, die die Verwendung der Rote-Liste-Arten betreffen, um für die Biodiversität wichtige Gebiete zu identifizieren. Objektive und systematische Erfassungen der Rote-Liste-Arten in Waldlandschaften inklusive der jüngeren Bestände sind dringend.     

Hypoxia-induced pulmonary endothelin-1 expression is unaltered by nitric oxide.

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O(2)) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso-N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O(2)) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O(2)) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O(2)) exposure. ET-1 promoter activity after S-nitroso-N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.     

No effects on myocardial ischaemia in patients with stable ischaemic heart disease after treatment with ramipril for 6 months

Objective  

To assess the effects of a 6-month angiotensin-converting enzyme (ACE) inhibitor intervention on myocardial ischaemia.     

Development of a Saccharomyces cerevisiae Strain with Enhanced Resistance to Phenolic Fermentation Inhibitors in Lignocellulose Hydrolysates by Heterologous Expression of Laccase

To improve production of fuel ethanol from renewable raw materials, laccase from the white rot fungus Trametes versicolor was expressed under control of the PGK1 promoter in Saccharomyces cerevisiae to increase its resistance to phenolic inhibitors in lignocellulose hydrolysates. It was found that the laccase activity could be enhanced twofold by simultaneous overexpression of the homologous t-SNARE Sso2p. The factors affecting the level of active laccase obtained, besides the cultivation temperature, included pH and aeration. Laccase-expressing and Sso2p-overexpressing S. cerevisiae was cultivated in the presence of coniferyl aldehyde to examine resistance to lignocellulose-derived phenolic fermentation inhibitors. The laccase-producing transformant had the ability to convert coniferyl aldehyde at a faster rate than a control transformant not expressing laccase, which enabled faster growth and ethanol formation. The laccase-producing transformant was also able to ferment a dilute acid spruce hydrolysate at a faster rate than the control transformant. A decrease in the content of low-molecular-mass aromatic compounds, accompanied by an increase in the content of high-molecular-mass compounds, was observed during fermentation with the laccase-expressing strain, illustrating that laccase was active even at the very low levels of oxygen supplied. Our results demonstrate the importance of phenolic compounds as fermentation inhibitors and the advantage of using laccase-expressing yeast strains for producing ethanol from lignocellulose.     

Genetic Retargeting of Adenovirus: Novel Strategy Employing “Deknobbing” of the Fiber

For efficient and versatile use of adenovirus (Ad) as an in vivo gene therapy vector, modulation of the viral tropism is highly desirable. In this study, a novel method to genetically alter the Ad fiber tropism is described. The knob and the last 15 shaft repeats of the fiber gene were deleted and replaced with an external trimerization motif and a new cell-binding ligand, in this case the integrin-binding motif RGD. The corresponding recombinant fiber retained the basic biological functions of the natural fiber, i.e., trimerization, nuclear import, penton formation, and ligand binding. The recombinant fiber bound to integrins but failed to react with antiknob antibody. For virus production, the recombinant fiber gene was rescued into the Ad genome at the exact position of the wild-type (WT) fiber to make use of the native regulation of fiber expression. The recombinant virus Ad5/FibR7-RGD yielded plaques on 293 cells, but the spread through the monolayer was two to three times delayed compared to WT, and the ratio of infectious to physical particles was 20 times lower. Studies on virus tropism showed that Ad5/FibR7-RGD was able to infect cells which did not express the coxsackie-adenovirus receptor (CAR), but did express integrins. Ad5/FibR7-RGD virus infectivity was unchanged in the presence of antiknob antibody, which neutralized the WT virus. Ad5/FibR7-RGD virus showed an expanded tropism, which is useful when gene transfer to cells not expressing CAR is needed. The described method should also make possible the construction of Ad genetically retargeted via ligands other than RGD.     

The role of human disturbance in Late Holocene vegetation changes on Kullaberg, southern Sweden

A pollen record from a small peatland located on Kullaberg in northwestern Sk?ne, southern Sweden, revealed that grazing pressure might have been the major disturbance agent controlling the vegetation, at least from ca. 1500 B. C. until the latter part of the nineteenth century. The pollen data also indicate a step-by-step increase in grazing pressure, expressed as a marked increase in non-arboreal pollen representation at ca. 1500 B. C., A. D. 650 and A. D. 1650. The increase at A. D. 650 probably indicates a more regular and intensive use of the area, resulting in a forest structure that was much more open than earlier, together with an expansion of Fagus, which rapidly replaced Quercus as the local forest dominant. At about this time the first patches of heath vegetation originated, but they probably only covered a small part of Kullaberg. Larger areas with an intensively grazed Calluna heath, as shown by eighteenth century maps, probably evolved around ca. A. D. 1650, when much of Kullaberg seems to have been deliberately deforested. Received February 20, 2001 / Accepted September 12, 2001     

Survival rates and causes of mortality of roe deer <Emphasis Type="Italic">Capreolus capreolus</Emphasis> in a rural landscape,eastern Poland

Game species in the cultural landscapes of Europe are exposed to several sources of anthropogenic pressure. Whilst hunting is part of coordinated wildlife management, poaching is difficult to quantify, and hence, relatively little is known about its impact on survival patterns of game species. We estimated survival and cause-specific mortality rates of 31 roe deer Capreolus capreolus in the surroundings of the Bia?owie?a Primeval Forest, eastern Poland, from 2010 to 2013. The study area consisted of large, extensively used agricultural fields and a mosaic of pine plantations, which were interspersed with natural forest stands and small agricultural fields and meadows. Roe deer were regularly hunted and the forested part of the study area was traversed by large carnivores. Annual survival rate of all deer was 0.69 and did not differ between seasons. Annual survival rates of females and males in each age class (young and adult) were similar. Poaching was a major source of mortality (6 out of 13 roe deer deaths), and poachers did not prefer any sex or age. Adult survival (0.77) was higher than survival of young individuals (0.53); this trend was stronger when poaching was excluded from the analysis. All cases of poaching were recorded between mid-September and February. Although the two parts of the study area were exposed to a similar degree of anthropogenic pressure, all poached individuals occupied home ranges in the mosaic, where the forest cover in home ranges of roe deer was significantly higher than in the field.