Effects of recreational fishing on zooplankton communities of drainage system reservoirs at an open‐pit mine

The use of artificial water bodies for angling is a popular practice, especially in industrial and urbanised areas where natural water bodies are lost. In this study, the zooplankton structure dynamics and water quality at three strip mine drainage system reservoirs were assessed with different types of recreational fishery exploitation: K1—intensive angling using the catch‐and‐release model, K2—lowest angling pressure and higher share of predatory fishes and K3—moderate fishing, that is limiting groundbait quantities and eliminating non‐predatory fishes by anglers. The null hypothesis tested was that recreational fishing does not affect the biotic and abiotic conditions of reservoirs. The significance of each environmental variable was tested using redundancy analysis (RDA). The highest nutrients and chlorophyll a concentration, turbidity level and organic matter content occurred in K1. Zooplankton diversity was the lowest under these conditions; protozoa and larval stages of copepods dominated. In reservoirs where sustainable fishing was implemented (K2, K3), trophic parameters of water were lower, on average, by 25%, turbidity by 30%, and productivity by 35–70%. Zooplankton diversity was significantly higher; rotifers and small cladocerans dominated. The choice of recreational fishing model determines the functionality and biological potential of the reservoir.     

A high-density Diversity Arrays Technology (DArT) microarray for genome-wide genotyping in <Emphasis Type="Italic">Eucalyptus</Emphasis>

Background  

A number of molecular marker technologies have allowed important advances in the understanding of the genetics and evolution of Eucalyptus, a genus that includes over 700 species, some of which are used worldwide in plantation forestry. Nevertheless, the average marker density achieved with current technologies remains at the level of a few hundred markers per population. Furthermore, the transferability of markers produced with most existing technology across species and pedigrees is usually very limited. High throughput, combined with wide genome coverage and high transferability are necessary to increase the resolution, speed and utility of molecular marker technology in eucalypts. We report the development of a high-density DArT genome profiling resource and demonstrate its potential for genome-wide diversity analysis and linkage mapping in several species of Eucalyptus.     

Cardiovascular,endocrine and behavioural responses to suckling and permanent separation in goats

Background

Suckling can be a peaceful or vulnerable event for goats and kids, whereas, separation is suggested as stressful. The aim of this study was to investigate physiology and behaviour in these two different situations in dairy goats.

Methods

Four studies were performed with seven goats kept with their first-born kid in individual boxes. The goats were videotaped and heart rate and arterial blood pressure were recorded every minute by telemetry from parturition until 24 hours after separation. One to two days after parturition, Study 1 was performed with analyses of heart rate and blood pressure around a suckling. In Study 2, performed 3-5 days after parturition, blood sampling was done before, during and after suckling. Study 3 was performed 4-6 days post partum, with blood sampling before and after a permanent goat and kid separation. In addition, vocalisations were recorded after separation. Blood samples were obtained from a jugular vein catheter and analysed for plasma cortisol, β-endorphin, oxytocin, and vasopressin concentrations. Study 4 was performed during the first (N1) and second nights (N2) after parturition and the nights after Study 2 (N3) and 3 (N4). Heart rate, blood pressure and time spent lying down were recorded.

Results

The kids suckled 2 ± 0.2 times per hour and each suckling bout lasted 43 ± 15 s. In Study 1, heart rate and blood pressure did not change significantly during undisturbed suckling. In Study 2, plasma cortisol (P ≤ 0.05 during suckling and P ≤ 0.01 five minutes after suckling) and β-endorphin (P ≤ 0.05) concentrations increased during suckling, but oxytocin and vasopressin concentrations did not change. In Study 3, the goats and kids vocalised intensively during the first 20 minutes after separation, but the physiological variables were not affected. In Study 4, heart rate and arterial blood pressure declined gradually after parturition and were lowest during N4 (P ≤ 0.05) when the goats spent longer time lying down than during earlier nights (P ≤ 0.01 during N1 and N3 and P ≤ 0.05 during N2).

Conclusions

Suckling elevated plasma cortisol and β-endorphin concentrations in the goats. The intensive vocalisation in the goats after separation, earlier suggested to indicate stress, was not accompanied by cardiovascular or endocrine responses.     

Artificial spawning of common tench <Emphasis Type="Italic">Tinca tinca</Emphasis> (Linnaeus, 1758), obtained from wild and domestic stocks

The study encompasses three reproduction seasons. Tench spawners caught during the spawning season originated from carp ponds (domestic stock) and a lake (wild stock). Fish were reproduced under controlled conditions after hormonal stimulation with GnRHa-containing pellets combined with metoclopramide (Ovopel) or carp pituitary homogenate (CPH). As a result of hormonal stimulation, eggs were obtained from a larger number of females originating from the lake (71.7%) than those originating from the pond (58.3%), although no other statistical differences were found. A similar relationship was recorded for the spermatozoa motilities (range from 72 to 76%). The obtained results indicate that both investigated reservoirs are suitable for tench broodstock management due to the fact that synchronization of ovulation among different stocks is easy to achieve. For this purpose, among the tested spawning agents, Ovopel could be recommended as being slightly more effective.     

Enzymic release of reducing sugars from oat hulls by cellulase,as influenced by Aspergillus ferulic acid esterase and trichoderma xylanase

Hydroxycinnamic acids, mainly ferulic and p-coumaric acids, are believed to be inhibitory to ruminal biodegradability of complex cell wall materials such as oat hulls. Previous studies have shown that a novel enzyme, Aspergillus ferulic acid esterase, and Trichoderma xylanase act synergistically to break the ester linkage between ferulic acid and the attached sugar of feruloyl polysaccharides, releasing ferulic acid from oat hulls. In this paper, we examined the enzymic release of reducing sugars from oat hulls by the actions of individual enzymes (Aspergillus ferulic acid esterase at 13 mU, 6.4 U, and 4678.4 U/assay; cellulase at 20 levels, ranging from 7.8 mU to 2772.7 U/assay; Trichoderma xylanase at 20 levels, ranging from 7.8 mU to 4096 U/assay) and by the combined action of cellulase at six levels (62.5 mU, 2 U, 16 U, 128 U, 1024 U, and 2772.7 U/assay), Aspergillus ferulic acid esterase at 13 mU/assay, and Trichoderma xylanase at two levels (1 U and 256 U/assay). The amount of total acid-extractable reducing sugars in the oat hulls used in this study was 793.8 +/- 8.0 microg/mg. The results show that after a 24-h incubation with Aspergillus ferulic acid esterase alone, no reducing sugars were observed to be released from oat hulls. With cellulase as the sole enzyme, as the concentration increased from 7.8 mU to 2772.7 U/assay, the release of reducing sugars increased (P < 0.01) from 0 to 39% of the total present, with the highest release at 512 U/assay. With Trichoderma xylanase alone, as the concentration increased from 7.8 mU to 4096 U/assay, the release of reducing sugars increased (P < 0.01) from 4.9 to 33%, with the highest release at 2048 U/assay. When incubated together with Trichoderma xylanase (1 U or 256 U/assay) and Aspergillus ferulic acid esterase (13 mU/assay), cellulase at all six levels (62.5 mU, 2 U, 16 U, 128 U, 1024 U and 2772.7 U/assay) significantly increased the release of reducing sugars (P < 0.01) from 8 to 69%. These results indicate that the synergistic interaction between Aspergillus ferulic acid esterase and Trichoderma xylanase on the release of ferulic acid from feruloyl polysaccharides of oat hulls makes the remainder of the polysaccharides open for further hydrolytic attack and facilitates the accessibility of the main chain of polysaccharides to cellulase. This action extends the cell wall hydrolysis, thus releasing a higher yield of reducing sugars. Such enzymic pretreatment of oat hulls may provide a unique advantage to rumen microorganisms for the biodegradation of the complex cell walls of byproduct feeds such as oat hulls.     

Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions

In recent years, policy‐makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non‐target species that are unknowingly released alongside intentionally‐introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan‐continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.     

The distribution of sequentially extracted Cu,Pb, and Zn fractions in Podzol profiles under dwarf pine of different stages of degradation in subalpine zone of Karkonosze Mts (central Europe)

Journal of Soils and Sediments - Here, we aimed to assess the contamination of Podzol soils in a subalpine zone of the Karkonosze Mountains. Cu, Pb, and Zn concentrations in the soil and the...     

Pharmacokinetic profiles of the analgesic flupirtine in dogs after the administration of four pharmaceutical formulations

ObjectiveFlupirtine (FLU) is a non-opioid analgesic with no antipyretic or anti-inflammatory effects which is used in the treatment of pain in humans. There is a substantial body of evidence on the efficacy of FLU in humans but this is inadequate for the recommendation of its off-label use in veterinary clinical practice. The aim of this study was to evaluate the pharmacokinetic profiles of FLU after intravenous (IV), oral immediate release (POIR), oral prolonged release (POPR) and rectal (RC) administrations in healthy dogs.Study designFour-treatment, single-dose, four-phase, unpaired, cross-over design (4 × 4 Latin-square).AnimalsSix adult Labrador dogs.MethodsAnimals in groups 1, 2 and 4 received a single dose of 5 mg kg⁻¹ FLU administered by IV, POIR and RC routes. Group 3 received a single dose of 200 mg subject⁻¹ via the POPR route. The wash-out periods were 1 week. Blood samples (1 mL) were collected at assigned times for 48 hours and plasma FLU concentrations were analysed by a validated HPLC method.ResultsAdverse effects including salivation, tremors and vomiting were noted in the IV group and resolved spontaneously within 10 minutes. These effects did not occur in the other groups. The FLU plasma concentrations were detectable in all of the treatment groups for 36 hours following administration. The pharmacokinetic profiles after extravascular administrations showed similar trends. The bioavailability values after POIR, POPR and RC were 41.93%, 36.78% and 29.43%, respectively. There were no significant differences in pharmacokinetic profiles between the POIR and POPR formulations. A 5 mg kg⁻¹ POIR dose or a 200 mg subject⁻¹ POPR dose gave plasma concentrations similar to those reported in humans after clinical dosing.Conclusion and clinical relevanceThis study provides pharmacokinetic data that can be used to design further studies to investigate FLU in dogs.     

Unexpected disproportion observed in species composition between oak mixed stands and their progeny populations

We used morphological analysis to assess species composition of natural regenerations and progeny plantations established from two mixed oak stands in Jamy and Legnica, Poland. Despite equal proportions of pedunculate (Quercus robur) and sessile oak (Quercus petrea) in seed stands, the species composition differed strikingly. In all progeny populations, pedunculate oak dominated, reaching 89.5% and 96.6% in Legnica and Jamy, respectively. However, sessile oak predominated in natural regenerations. Morphological studies indicated a varied number of phenotypically intermediate or mosaic individuals. Among artificial populations, the highest number of putative hybrids was observed in Legnica (average 2.5%) and the lowest in Jamy (average 0.2%). Hybrids in natural regeneration were 1% in Legnica and 8% in Jamy. The disproportionate species composition could result from either unintentional indirect acorn selection during collection or selection in nursery practice. We discuss the role of ecophysiological differences between species in biased species representation in progeny populations.     

Influence of wheat leaf position on leaf rust severity

Summary The relation between flag leaf position and leaf rust severity was investigated in field experiments. Different leaf angles were obtained by attaching ends of flag leaves to strings stretched at different heights along wheat rows. Leaves with angles between lamina and stem of 0° and 45° were significantly less diseased than leaves with horizontal and pendulous positions. In the experiment with seedlings, spore settling and uredia number were significantly lower on erect than on horizontal leaves. The influence of wheat leaf position changes on leaf rust severity was discussed. It has been suggested that breeding of wheat cultivars with erect leaves can improve their resistance to airborne pathogens.