Alluvial aquifer contamination: Exchangeable heavy metals and factors affecting their spatial distribution

The distributions of ammonium acetate — extracted (‘exchangeable’) Co, Ni, Cu, Zn, Cd and Pb were determined in alluvial sediments of the Sava River at Novi Beograd (Belgrade aquifer, Yugoslavia). Samples were taken from the river bottom and from three drill-holes in the alluvial formation (in increasing distance from the river-bed). The alluvial samples included the quaternary formation — humified surface layers, sands and clays, as well as some samples from the impervious tertiary layer at about 25 m depth. A combined method for the interpretation of results was introduced in order to obtain a clear insight into the factors of heavy metal distribution within the examined aquifer sequence, including elementary statistical methods, as well as factor analysis. There are no significant correlations between metal concentrations and burial depth, river distance, or lithologic type. The application of factor analysis on the exchangeable metal phase, however, reveals the existence of two sample populations and two dominant ecochemical factors, governing the distribution of heavy metals within the aquifer. One factor representssurface contamination, and the other representsriver water influence, accumulating exchangeable heavy metals within a sharply outlined zone. This zone spreads over most layers in the immediate vicinity of the river, as well as over a few, more distant layers which are at roughly the same level as the river-bed.     

Relationships between adipose tissue characteristics of newborn pigs and subsequent performance: I. Characteristics at 8 days of age and growth rate until slaughter

The genetic influence on body and adipose tissue characteristics of newborn pigs and their correlations to growth rate, BW, body length, backfat thickness and adipocyte size in the outer and inner layers of backfat in 8-d-old Large White piglets were determined. Samples of adipose tissue were obtained by biopsy. Pigs were born to 32 sows mated with the same boar. Heritability and genetic correlations were estimated with dam component of variance; therefore, bias due to common environmental effects cannot be excluded. The heritability estimate for adipocyte volume (.89 +/- .28) was higher than that for backfat thickness at the first and last thoracic vertebrae (.50 +/- .22; .63 +/- .24) and for body weight (.59 +/- .23) at 8 d. Backfat thickness was more closely related genetically and phenotypically to body weight and length than to adipose tissue cellularity. Heritability estimates were .75 +/- .28 for gain from 8 d to weaning and from weaning to 95 d (probably because of common environmental effects) but were .31 +/- .20 for ADG from 95 d to slaughter. Characteristics at 8 d were closely correlated phenotypically with growth rate until weaning. These correlations became lower in the two subsequent periods (to 95 d and to slaughter). Corresponding genetic correlations were nonsignificant.     

A study of Bovid herpesvirus 2 infection in calves inoculated intradermally or intranasally

Bovid herpesvirus 2 infection was studied in calves exposed to the virus by intradermal inoculation of the skin of the left cheek or by nasal spray.

In either case a localised infection developed and virus replication was shown to occur mostly in the tissues of its primary localisation, i.e. the skin of the left cheek or the nasal mucosa. There were neither secondary lesions, except at the site of virus injection, nor any serious systemic involvement on the part of the animals.

The virus was also recovered from some areas of the skin (right cheek, perineum and scrotum) that were free of macroscopic lesions; moreover, intranuclear inclusions were found in several tissues of the nervous system (brain, superior cervical, stellate and Gasserian ganglia) which did not show any signs of inflammatory or degenerative changes. These findings suggest that the skin and the nervous system play an important role in the naturally-occurring disease since they could be the sites where the virus is maintained latently in the host.     

Increase of serum lipid-associated sialic acid concentration in dogs with neoplasms

Serum concentrations of lipid-associated sialic acid (LASA) were determined in sera obtained from 26 apparently healthy dogs (group 1), 56 dogs with nonneoplastic disorders (group 2), and 100 dogs with neoplasms (benign [group 3], malignant [group 4]), using a simple, reliable, rapid spectrophotometric procedure. The LASA concentrations were significantly increased (P less than 0.01) in group 4 dogs (malignant neoplasms) when compared with those in dogs from groups 1, 2, and 3. The sensitivity of the test was between 71.5% and 100%, and specificity was 92.3% for group 1, 67.8% for group 2, and 80.6% for group 3. A preliminary study concerning variations of serum LASA values as a marker after surgical treatment of tumor showed a good correlation between effectiveness of therapy and serum LASA concentrations.     

QTL detection for milk production traits in goats using a longitudinal model.

Eight paternal half-sib families were used to identify chromosomal regions associated with variation in the lactation curves of dairy goats. DNA samples from 162 animals were amplified by PCR for 37 microsatellite markers, from Capra hircus autosomes CHI3, CHI6, CHI14 and CHI20. Milk samples were collected during 6 years, and there were 897 records for milk yield (MY) and 814 for fat (FP) and protein percentage (PP). The analysis was conducted in two stages. First, a random regression model with several fixed effects was fitted to describe the lactation function, using a scale (alpha) plus four shape parameters: beta and gamma, both associated with a decrease in the slope of the curve, and delta and phi that are related to the increase in slope. Predictions of alpha, beta, gamma, delta and phi were regressed using an interval mapping model, and F-tests were used to test for quantitative trait loci (QTL) effects. Significant (p < 0.05) QTLs were found for: (i) MY: CHI6 at 70-80 cM for all parameters; CHI14 at 14 cM for delta and phi; (ii) FP: CHI14, at 63 cM was associated with beta; CHI20, at 72 cM, showed association with alpha; (iii) PP: chromosomal regions associated with beta were found at 59 cM in CHI3 and at 55 cM in CHI20 with alpha and gamma. Analyses using more families and more animals will be useful to confirm or to reject these findings.     

Biochemical and pharmacological characterization of adenosine A1 receptors in eel (Anguilla anguilla) brain

N⁶-cyclohexyl[³H]adenosine ([³H]CHA) was used to label adenosine A1 receptors in membranes prepared from male and female eel whole brain. The A1 receptor agonist [³H]CHA bound saturably, reversibly and with high affinity (K_d = 0.91 ± 0.12 nM; B_max = 120.36 ± 5.2 fmol mg⁻¹ protein). In equilibrium competition experiments, the adenosine agonists and antagonists all displaced [³H]CHA from high-affinity binding sites with the rank order of potency in displacing, characteristics of an A1 adenosine receptor. Mg²⁺ dramatically increased the affinity of [³H]CHA without modifying the maximal binding capacity. The specific binding was inhibited by guanosine 5′-triphosphate (K_i = 2.54 ± 0.98 μM). The [³H]CHA binding sites are ubiquitously distributed with a maximum in cerebellum and a minimum in olfactory bulb. No difference was observed between male and female brain. In eel brain, synaptosomes (P2), stimulation of adenosine 3′,5′-monophosphate (cyclic AMP) accumulation with 10⁻⁵ M forskolin was markedly reduced (45.5%) by treatment with the adenosine A1 receptor agonist CHA (10⁻⁴ M), and the reduction was reversed in presence of the selective A1 receptor antagonist 8-cyclopentyltheophylline (10⁻⁵ M). In superfused eel cerebellar synaptosomes, K⁺ stimulated the release of adenosine in a partially Ca²⁺-dependent manner. The findings, taken together, suggest the hypothesis that adenosine A1 receptors present in eel brain could modulate synaptic transmission, as A1 receptors do in other vertebrates.     

Fish welfare and quality as affected by pre-slaughter and slaughter management

. A reliable assessment of animal welfare-suffering and of its impact on product quality requires a multidisciplinary approach that takes into account fish behaviour and the different biochemical and physiological processes involved. This might be done by the contemporary study of changes of indicators of brain function, endocrine responses, post mortem tissue biochemical processes and quality changes. This work reviewed some of the most used indices of stress at the time of slaughter, commercial slaughter methods and related stress effects on physical and biochemical parameters of fish quality. The set of the available data seemed to indicate that, although of some results appear contradictory, pre-slaughter and slaughter stressful practices could have an important effect on the flesh quality in fish. A clear effect emerged mostly on the physical properties of flesh, because severe stress at slaughter time exhausted muscular energies, produced more lactic acid, reduced muscular pH, increased the rate of rigor mortis onset. In this way they could have significant negative effects on technological traits, flesh quality and keeping quality of fish. Asphyxia and electrically stunned fish were more stressed than spiked, knocked and live chilled fish. Combining various methods together might be a more satisfactory strategy for both animal welfare and product quality.     

Fermentation Technologies for the Optimization of Marine Microbial Exopolysaccharide Production

In the last decades, research has focused on the capabilities of microbes to secrete exopolysaccharides (EPS), because these polymers differ from the commercial ones derived essentially from plants or algae in their numerous valuable qualities. These biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications. In marine microorganisms the produced EPS provide an instrument to survive in adverse conditions: They are found to envelope the cells by allowing the entrapment of nutrients or the adhesion to solid substrates. Even if the processes of synthesis and release of exopolysaccharides request high-energy investments for the bacterium, these biopolymers permit resistance under extreme environmental conditions. Marine bacteria like Bacillus, Halomonas, Planococcus, Enterobacter, Alteromonas, Pseudoalteromonas, Vibrio, Rhodococcus, Zoogloea but also Archaea as Haloferax and Thermococcus are here described as EPS producers underlining biopolymer hyperproduction, related fermentation strategies including the effects of the chemical composition of the media, the physical parameters of the growth conditions and the genetic and predicted experimental design tools.