Maximizing dietary information retrievable from carcasses of Great Cormorants Phalacrocorax carbo using a combined morphological and molecular analytical approach

Avian carcasses can provide important information on the trophic ecology of birds. Usually, the number of carcasses available for examination is limited and therefore it is important to gain as much dietary information per specimen as possible. In piscivorous birds and raptors, the stomach has been the primary source of dietary information, whereas the gut (intestine) has so far been neglected as it usually contains only a few morphologically identifiable hard parts of prey. Molecular approaches have the potential to retrieve dietary information from the gut, although this has not yet been verified. As well as identifying the prey, it is important to estimate any secondary predation to avoid food web errors in dietary analyses. The assignment of accidentally consumed prey is notoriously difficult regardless of the prey identification approach used. In the present study, morphological and molecular analyses were, for the first time, combined to maximize the dietary information retrievable from the complete digestive tract of Great Cormorants Phalacrocorax carbo sinensis. Moreover, a novel approach based on predator–prey size ratios was applied to these piscivorous birds to minimize the number of samples that might contain secondarily predated prey. The stomach contents of the examined birds were found to provide the most dietary information when morphological and molecular analyses were used in combination. However, compared with the morphological approach, the molecular analysis increased the number of fish species detected by 39%. The molecular approach also permitted the identification of fish DNA in the Cormorant guts. Predator–prey size ratios derived from morphological analysis of fish hard parts can reduce the incidence of potential confounding influence of secondarily predated prey by 80%. Our findings demonstrate that a combination of morphological and molecular approaches maximizes the trophic information retrievable from bird carcasses.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

Battery-powered miniature implant for electrical nerve stimulation.

The range of application of implantable stimulators in functional electrical stimulation (FES) for therapeutic purposes and for the restoration of lost or damaged functions has steadily grown within the last 20 years. Each time a clinically used method is improved, a new field of FES application explored or basic research conducted, animal experiments are needed to check and evaluate the findings and results. It is precisely for this use that the stimulation system described in this paper was developed. The battery-powered single-channel stimulator can be used for the excitation of motor and sensory nerves with monophasic or biphasic impulses. All parameters and functions are programmable via the bidirectional telemetry circuit. Implant programming is achieved by a laptop computer, supported by a graphical user interface, instead of by a specially designed programmer. The maximum settings of the stimulation parameters are: frequency 100 Hz, monophasic pulse duration 0.8 ms, biphasic pulse duration 1.6 ms, stimulation current 3 mA. The implant volume was reduced to 2 cm3 (length 23 mm, width 13 mm, height 7.5 mm), lowering the weight to 3.6 g. Due to this small volume the implant can be used in small animals. The power supply via battery obviates the need for transcutaneous tunneling or permanent external high-frequency senders and facilitates the keeping of the animals.     

Binding and catalysis by yeast aldose reductase: a substrate-analog approach with new aldose derivatives.

5-Deoxy-D-xylofuranose derivatives and a range of new 5,6-dideoxy analogs of D-glucofuranose bearing azido or fluoro substituents were synthesised and employed as substrates of the NADH-dependent aldehyde reduction catalysed by yeast aldose reductase. In terms of catalytic efficiencies, these products proved to be superior to the parent compounds.     

Sudden origins

Sudden Origins: Fossils, Genes, and the Emergence of Species (1999). Schwartz, JH. John Wiley & Sons, 420 pp, £22.50, hbk; ISBN 0471329851 © 1999 John Wiley & Sons, Inc.     

On the purported presence of fossilized collagen fibres in an ichthyosaur and a theropod dinosaur

Since the discovery of exceptionally preserved theropod dinosaurs with soft tissues in China in the 1990s, there has been much debate about the nature of filamentous structures observed in some specimens. Sinosauropteryx was the first non‐avian theropod to be described with these structures, and remains one of the most studied examples. Despite a general consensus that the structures represent feathers or feather homologues, a few identify them as degraded collagen fibres derived from the skin. This latter view has been based on observations of low‐quality images of Sinosauropteryx, as well as the suggestion that because superficially similar structures are seen in Jurassic ichthyosaurs they cannot represent feathers. Here, we highlight issues with the evidence put forward in support of this view, showing that integumentary structures have been misinterpreted based on sedimentary features and preparation marks, and that these errors have led to incorrect conclusions being drawn about the existence of collagen in Sinosauropteryx and the ichthyosaur Stenopterygius. We find that there is no evidence to support the idea that the integumentary structures seen in the two taxa are collagen fibres, and confirm that the most parsimonious interpretation of fossilized structures that look like feather homologues in Sinosauropteryx is that they are indeed the remains of feather homologues.     

Association genetics of phenolic needle compounds in Norway spruce with variable susceptibility to needle bladder rust

Key message

Accumulation of phenolic needle metabolites in Norway spruce is regulated by many genes with small and additive effects and is correlated with the susceptibility against fungal attack.

Abstract

Norway spruce accumulates high foliar concentrations of secondary phenolic metabolites, with important functions for pathogen defence responses. However, the molecular genetic basis underlying the quantitative variation of phenolic compounds and their role in enhanced resistance of spruce to infection by needle bladder rust are unknown. To address these questions, a set of 1035 genome-wide single nucleotide polymorphisms (SNPs) was associated to the quantitative variation of four simple phenylpropanoids, eight stilbenes, nine flavonoids, six related arithmetic parameters and the susceptibility to infection by Chrysomyxa rhododendri in an unstructured natural population of Norway spruce. Thirty-one significant genetic associations for the flavonoids gallocatechin, kaempferol 3-glucoside and quercetin 3-glucoside and the stilbenes resveratrol, piceatannol, astringin and isorhapontin were discovered, explaining 22–59% of phenotypic variation, and indicating a regulation of phenolic accumulation by many genes with small and additive effects. The phenolics profile differed between trees with high and low susceptibility to the fungus, underlining the importance of phenolic compounds in the defence mechanisms of Norway spruce to C. rhododendri. Results highlight the utility of association studies in non-model tree species and may enable marker-assisted selection of Norway spruce adapted to severe pathogen attack.

     

Real‐time pH monitoring of industrially relevant enzymatic reactions in a microfluidic side‐entry reactor (μSER) shows potential for pH control

Monitoring and control of pH is essential for the control of reaction conditions and reaction progress for any biocatalytic or biotechnological process. Microfluidic enzymatic reactors are increasingly proposed for process development, however typically lack instrumentation, such as pH monitoring. We present a microfluidic side‐entry reactor (μSER) and demonstrate for the first time real‐time pH monitoring of the progression of an enzymatic reaction in a microfluidic reactor as a first step towards achieving pH control. Two different types of optical pH sensors were integrated at several positions in the reactor channel which enabled pH monitoring between pH 3.5 and pH 8.5, thus a broader range than typically reported. The sensors withstood the thermal bonding temperatures typical of microfluidic device fabrication. Additionally, fluidic inputs along the reaction channel were implemented to adjust the pH of the reaction. Time‐course profiles of pH were recorded for a transketolase and a penicillin G acylase catalyzed reaction. Without pH adjustment, the former showed a pH increase of 1 pH unit and the latter a pH decrease of about 2.5 pH units. With pH adjustment, the pH drop of the penicillin G acylase catalyzed reaction was significantly attenuated, the reaction condition kept at a pH suitable for the operation of the enzyme, and the product yield increased. This contribution represents a further step towards fully instrumented and controlled microfluidic reactors for biocatalytic process development.     

Tertiary plotopterids (Aves, Plotopteridae) and a novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae)

Plotopterids (Aves: Plotopteridae) are extinct wing-propelled diving birds which exhibit a strikingly similar wing morphology to penguins (Spheniscidae), but also share derived characters with 'pelecaniform' birds that are absent in penguins. The similarities between Plotopteridae and Spheniscidae have hitherto been attributed to convergence, and plotopterids were considered to be most closely related to the 'pelecaniform' Phalacrocoracidae (cormorants) and Anhingidae (anhingas). However, here I show that assignment of plotopterids to 'pelecaniform' birds does not necessarily preclude them from being the sister taxon of penguins. Cladistic analysis of 68 morphological characters resulted in sister group relationship between Plotopteridae and Spheniscidae, and the clade (Plotopteridae + Spheniscidae) was shown to be the sister taxon of the Suloidea, i.e. a clade including Sulidae (boobies and gannets), Phalacrocoracidae, and Anhingidae. Derived characters are discussed which support this novel hypothesis. Paedomorphosis probably accounts for the absence of derived characters in penguins that are shared by Plotopteridae and members of the Steganopodes. Plotopterids exemplify the importance of fossil birds for analyzing the phylogenetic relationships of modern taxa that exhibit a highly apomorphic morphology.     

A small loon and a new species of large owl from the Rupelian of Belgium (Aves: Gaviiformes,Strigiformes)

The early Oligocene Boom Formation in Belgium yielded many avian remains from the Rupelian unit-stratotype, most of which have remained unstudied so far. Here, I describe a small loon (Gaviiformes) and a new species of large owl (Strigiformes) that are represented by associated bones of a single individual each. The loon, of which wing and pectoral girdle bones are preserved, is assigned to Colymboides (?) metzleri, a species previously known from a partial skeleton from the Rupelian of Germany. The owl is based on a tarsometatarsus and distal tibiotarsus and described as a new species, Selenornis steendorpensis. It constitutes the most substantial fossil record of the taxon Selenornis, which was before known from a distal tibiotarsus from an unknown horizon of the Quercy fissure fillings in southwestern France. It is detailed that there are differences in the higher level taxonomic composition of the known early Oligocene avifaunas of northern and southern Europe, which may reflect true zoogeographic facts owing to a different climate and vegetation.