The hand of birds revealed by early ostrich embryos

The problem of resolving the homology of the digits of the avian hand has been framed as a conflict between paleontological and embryological evidence, the former thought to support a hand composed of digits I, II, III, because of similarity of the phalangeal formulae of the earliest known bird Archaeopteryx to that of Mesozoic pentadactyl archosaurs, while embryological evidence has traditionally favored a II, III, IV avian hand. We have identified the critical developmental period for the major features of the avian skeleton in a primitive bird, the ostrich. Analysis of digit anlagen in the avian hand has revealed those for digits/metacarpals I and V, thus confirming previous embryological studies that indirectly suggested that the avian hand comprises digits II, III, IV, and was primitively pentadactyl.     

Polymeric Complexes from Casein and Starch Phosphate: Characteristics and Enzyme Susceptibility

Novel biodegradable materials were prepared from potato starch enriched in phosphato moieties (DS 0.018 and 0.033) and casein in defatted milk. The components were blended in proportions providing starch: casein ratios of 2:1, 1:1, and 1:2 and were then precipitated with hydrochloric acid. Aqueous solubility, water-binding capacity, infrared spectra, and thermal analysis (thermogravimetry[7] and differential thermogravimetry of the precipitates revealed that they were not simple physical mixtures of the components. The components interacted with one another electrostatically with involvement of the phosphate groups of starch and the peptide bond of casein, as documented by infrared spectra. Because of insolubility in 7 M aqueous urea solution, they might also be considered as complexes in which the components were chemically bound.     

Assessment of soils contamination with veterinary antibiotic residues in Northern Poland using developed MAE-SPE-LC/MS/MS methods

Among the wide range of compounds reaching the soil are the veterinary antimicrobials. Since no regulations regarding acceptable levels of drug concentrations in the environment exist, monitoring tests, particularly concerning soils, are carried out very rarely. This study presents a preliminary assessment of the contamination of agricultural soils in Northern Poland with seven antimicrobial veterinary medicines which has never been carried out before. Veterinary drugs were detected in 54% of the examined soil samples; the most commonly detected drugs were sulfonamides and trimethoprim. The highest indicated concentrations refer to enrofloxacin (57.0 μg kg^?1) and trimethoprim (47.8 μg kg^?1). The presence of these target drugs in the soil environment confirms the need for further monitoring studies. The analytical methods developed in this study are an excellent tool to achieve this goal and allow an estimation of the risk connected with the presence of veterinary antimicrobials in soils.

     

The effect of alkyl chain length on the degradation of alkylimidazolium- and pyridinium-type ionic liquids in a Fenton-like system

Background, aim, and scope  Ionic liquids are regarded as essentially “green” chemicals because of their insignificant vapor pressure and, hence, are a good alternative to the emissions of toxic conventional volatile solvents. Not only because of their attractive industrial applications, but also due to their very high stability, ionic liquids could soon become persistent contaminants of technological wastewaters and, moreover, break through into natural waters following classical treatment systems. The removal of harmful organic pollutants has forced the development of new methodologies known as advanced oxidation processes (AOPs). Among them, the Fenton and Fenton-like reactions are usually modified by the use of a higher hydrogen peroxide concentration and through different catalysts. The aim of this study was to assess the effect of hydrogen peroxide concentration on degradation rates in a Fenton-like system of alkylimidazolium ionic liquids with alkyl chains of varying length and 3-methyl-N-butylpyridinium chloride. Materials and methods  The ionic liquids were oxidized in dilute aqueous solution in the presence of two different concentrations of hydrogen peroxide. All reactions were performed in the dark to prevent photoreduction of Fe(III). The concentrations of ionic liquids during the process were monitored with high-performance liquid chromatography. Preliminary degradation pathways were studied with the aid of ¹H NMR. Results  Degradation of ionic liquids in this system was quite effective. Increasing the H₂O₂ concentration from 100 to 400 mM improved ionic liquid degradation from 57–84% to 87–100% after 60 min reaction time. Resistance to degradation was weaker, the shorter the alkyl chain. Discussion  The compound omimCl was more resistant to oxidation then other compounds, which suggests that the oxidation rates of imidazolium ionic liquids by OH· are structure-dependent and are correlated with the n-alkyl chain length substituted at the N-1-position. The level of degradation was dependent on the type of head group. Replacing the imidazolium head group with pyridinium increased resistance to degradation. Nonetheless, lengthening the alkyl chain from four to eight carbons lowered the rate of ionic liquid degradation to a greater extent than changing the head group from imidazolium to pyridinium. 1H-NMR spectra show, in the first stage of degradation, that it is likely that radical attack is nonspecific, with any one of the carbon atoms in the ring and the n-alkyl chain being susceptible to attack. Conclusions  The proposed method has proven to be an efficient and reliable method for the degradation of imidazolium ionic liquids by a Fenton-like reagent deteriorated with lengthening n-alkyl substituents and by replacing the imidazolium head group with pyridinium. The enhanced resistance of 1-butyl-3-methylpyridinium chloride when the resistance of imidazolium ionic liquids decreases with increasing H₂O₂ concentration is probably indicative of a change in the degradation mechanism in a vigorous Fenton-like system. H-NMR spectra showed, in the first stage of degradation, that radical attack is nonspecific, with any one of the carbon atoms in the ring and the n-alkyl chain being susceptible to attack. Recommendations and perspectives  Since ionic liquids are now one of the most promising alternative chemicals of the future, the degradation and waste management studies should be integrated into a general development research of these chemicals. In the case of imidazolium and pyridinium ionic liquids that are known to be resistant to bio- or thermal degradation, studies in the field of AOPs should assist the future structural design as well as tailor the technological process of these chemicals     

Sexual differences in food preferences in the white stork: an experimental study

Sex differences in the foraging ecology of monomorphic species are poorly understood, due to problems with gender identification in field studies. In the current study, we used experimental conditions to investigate the food preferences of the white stork Ciconia ciconia, an opportunistic species in terms of food, but characterised by a low level of sexual dimorphism. During a 10-day experiment, 29 individuals (20 females and 9 males) were studied by means of a ‘cafeteria test’ in which the storks’ diet consisted of mammals, birds, fish, amphibians, insects and earthworms. The storks preferred food characterised by high calorific and protein values such as mammals, birds and fish. Sexes differed strongly in their preferences; males preferred mammals, whereas females preferred birds. Moreover, females consumed insects and earthworms less often than males. Interestingly, males spent significantly less time foraging than females. We have demonstrated that the white stork exhibits clear sexual differences in food preferences which are mostly attributable to differences in parental duties, physiology and anatomy.     

Timing of arrival from spring migration is associated with flight performance in the migratory barn swallow

Timing of arrival at the breeding grounds by migratory birds affects their mating success and access to superior resources, thus being a major factor associated with fitness. Much empirical work has been devoted to investigate the condition dependence of arrival sequence of migrants and characteristics of individuals that influence arrival time from migration. Surprisingly, there are no studies examining the relationship between flight performance of individual birds and their arrival time. I investigated the relative importance of direct effects of short-term flight performance, age, body condition and the degree of sexual ornamentation (tail length) on timing of spring arrival in the barn swallow (Hirundo rustica), a long-distance trans-equatorial passerine migrant. I evaluated short-term flight performance (a composite variable comprising flight manoeuvrability, velocity and acceleration) in a standardised manner using flight tunnels. Short-term flight performance was a significant and important predictor of spring arrival date. Furthermore, locomotion predicted arrival date of individual birds independently of morphological variables—the degree of sexual ornamentation (the length of the tail) and wing aspect ratio and body condition. I discuss the possible role short-term flight performance may have in determining migratory performance. This is the first time flight performance has been shown to be associated with timing of arrival from migration in a migratory bird.     

Habitat selection by breeding waterbirds at ponds with size-structured fish populations

Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp (Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe (Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.     

The evaluation of energy consumption in transportation and processing of municipal waste for recovery in a waste-to-energy plant: a case study of Poland

Environmental Science and Pollution Research - Refuse-derived fuel (RDF) can be produced from combustible materials contained in municipal waste. This article investigates energy and material flow...     

Applied waste-free recovery of methanol

In this paper, we present applied methanol recycling technology utilising Chromatographic applications, which has been designed for an academic-size institution. The procedure is combined out of proper recovery technique and the biodegradation method intended for postprocessing residues. Additionally, analytical methods controlling the quality of the process are described in detail in order to enable full transfer of the proposed methodology to the analogous institution. The recovered solvent is of relatively high purity (> 99.92%), containing traces of water and volatile compounds. The spectral purity is sufficient to employ recycled methanol in HPLC applications where low wayelength detection is necessary. Biodegradation of distillation first-cuts and still bottoms is implemented using isolated strains ofMethylobacterium organophilum. During the biodegradation process, a series of carotenoids are biosynthesized, which are of a high commercial value. The proposed application, therefore, offers not only a sustainable, waste-free solution in handling methanol waste, but can also serve as a potential source of value.     

Profiles of enzymatic activity in earthworms from zinc, lead and cadmium polluted areas near Olkusz (Poland)

The aim of the study was to determine whether there are signs of adaptation of soil fauna to a gradient of heavy metal contamination. Earthworms Aporrectodea caliginosa, Lumbricus terrestris and Eisenia fetida were collected during the spring and summer of 2000 and 2001 from meadow sites situated between 2 and 32 km from the Bukowno-Olkusz complex of zinc-lead ore mines and smelters. The heavy metal content in the soil near smelters reaches 10,500 mg/kg (d.w.) for Zn, 2600 mg/kg for Pb and 81.9 mg/kg for Cd. The sites differ with respect to species composition of earthworm community, with A. caliginosa being dominant. Complete data was obtained only for A. caliginosa, since other species were not abundant at all investigated sites during the whole period of investigation. The body burdens of Zn, Pb, Cd and Cu in A. caliginosa reached 1500, 100, 220 and 10 microg/g, respectively, in the vicinity of the smelter (2-4 km), and decreased to 400, 2, 36 and 6 microg/g at the most distant site (32 km). Cadmium and lead content was significantly elevated in the whole body of L. terrestris collected at the site 2.5 km distant from the smelters when compared to more distant sites, while in E. fetida only the body burden of cadmium was elevated at the nearest site compared to the next site of transect. Activities of glutathione peroxidase (GPX; EC 1.11.1.9) against hydrogen peroxide (H2O2) or cumene hydroperoxide (cumOOH), glutathione reductase (GR; EC 1.6.4.2), glutathione S-transferase (GST; EC 2.5.1.18) and catalase (CAT; EC 1.11.1.6) were assayed in postmitochondrial supernatant obtained from whole body homogenates. Seasonal and annual variations of enzyme activity were reflected by higher GPX activity in the late summer of 2001 in comparison with the spring and summer of 2000. This may reflect severe drought in the spring and summer of 2000. The activity of both GPX isozymes, GR and GST in A. caliginosa and L. terrestris increased with increasing distance from the smelters and reached maximum at sites III and IV (4 and 8 km from the smelters, respectively) and then it decreased in the animals from site V (32 km). These may be the effects of antagonism between the enzyme inducing and enzyme inhibiting action of smelter emissions, a phenomenon known as a hormetic effect. It is postulated here that this effect is of diagnostic value for metal pollution biomonitoring.