Early cell-mediated immune responses to Marek's disease virus in two chicken lines with defined major histocompatibility complex antigens

N2a and P2a chickens, resistant and susceptible to Marek's disease (MD), respectively, were used to examine relationships between major histocompatibility complex (MHC)-restricted cytotoxic T lymphocytes (CTL) and natural killer (NK)-like cell activity with resistance to infection with Marek's disease virus (MDV). Ten-day-old chickens were infected with MDV and euthanatized at selected times to evaluate for NK cell and MHC-restricted cytotoxicity. The N2a MDV-infected chickens had an early cell-mediated immune response characterized by a sustained NK-like cytotoxicity that coincided with a measurable MHC-cytotoxicity that was lower than controls. Although MHC-restricted and NK cell cytotoxicity was demonstrated in P2a MDV-infected chickens at 8 dpi, both abruptly decreased and remained low for the remainder of the 20-day experiment. The critical time point that may determine the resistance to MD appears to be within the first 2 weeks post-infection. Improvement of the chicken NK cell activity may be a good candidate for both selection and immunomodulation MD control programs.     

Chronic chlordane toxicity: Effect on blood biochemistry of Meriones hurrianae Jerdon,the Indian desert gerbil

Indian desert gerbils, administered with repeated doses of 2.5 mg/kg body weight chlordane to study the chronic toxic effects, show changes in serum proteins, blood glucose, alkaline and acid phosphatase activities. The effect of chlordane includes hyperproteinemia, hyperglycemia, enhanced serum alkaline and acid phosphatase activity. Possible reasons for changes are discussed.     

Ecophysiology of the cave isopod Mesoniscus graniger (Frivaldszky, 1865) (Crustacea: Isopoda)

Feeding biology and thermal adaptations of the terrestrial isopod Mesoniscus graniger were studied. M. graniger is a depigmented isopod mainly inhabiting cave systems, although it has also been reported in endogeic (soil) habitats. Physiological adaptations are expected to reflect the unique environmental characteristics of caves, including restricted food sources, and stable microclimate with temperatures not exceeding about 10 °C and high relative humidity. The M. graniger from Domica and Ardovská caves (Slovakian Karst) were investigated. We identified organic deposits with associated microorganisms as sources exploited by M. graniger and assessed how these might supply essential polyunsaturated fatty acids (PUFA) in its nutrition. Algae, fungi and bat guano were found as the most important potential resources of PUFA for isopods. Digestive enzymes amylase, trehalase, saccharase and maltase were confirmed in the whole body homogenates of isopods; neither cellulolytic activity nor activities against xylan, laminaran and lichenan were observed. Amylase, maltase and cellobiase activities were also observed in bacterial strains isolated and cultured from isopod midgut, and may account for the measured whole-animal activities. In an artificial temperature gradient, M. graniger selected temperature 3.5 ± 5.4 °C with lower and upper extremes of –1.5 and 18.5 °C. Respiration, as measured by VO₂, was almost independent of temperature between 5 and 10 °C, then increased between 10 and 30 °C. These ecophysiological measures are consistent with adaptation to a stenothermal environment.     

Millipedes (Diplopoda) in birds nests

Nests of birds represent an unusual microhabitat for diverse groups of soil and epigeic invertebrates including millipedes. The millipede faunas of 301 birds nests from 63 localities throughout Slovakia were obtained by heat extraction of the nest substrates. In total 18 species of millipedes were found in 7 different types of nests of 40 bird species. The most frequent millipede species were Polyxenus lagurus and Proteroiulus fuscus. The similarities in the millipede nidifauna depending on the type of nests, ecological characteristics and geographical distribution of millipede species are discussed.     

Morphometric and genetic analysis of <Emphasis Type="Italic">Carassius auratus</Emphasis> complex from an artificial wetland in Morava River floodplain,Czech Republic

A Carassius auratus complex from an artificial wetland in the Morava River basin is composed of triploid females. Based on body depth, sampled females could be divided into two groups: (i) high-dorsal (42.5% of standard length); and (ii) low-dorsal (36.1% of standard length). Both groups differed also in number of gill rakers (50.2 versus 45.4, respectively). In concordance with morphological differences, genetic analysis proved the existence of two haplotypes in examined individuals. The first haplotype is bound to the high-dorsal form with higher number of gill rakers. This is the most frequent haplotype in populations of the C. a gibelio form in the Czech Republic. The second haplotype is characteristic of the low-dorsal form with a lower number of gill rakers. This haplotype is close to haplotypes described in the C. a. langsdorfii form, which is known from Japan. and its occurrence within haplotypes specified in European territory is sporadic.     

Efficient and economical way of operating a recirculation aquaculture system in an aquaponics farm

ABSTRACT

In this article, optimal control methods based on a metabolite-constrained fish growth model are applied to the operation of fish production in an aquaponic system. The system is formulated for the twin objective of fish growth and plant fertilization to maximize the benefits by optimal and efficient use of resources from aquaculture. The state equations, basically mass balances, required by the optimization algorithms are given in the form of differential equations for the number of fish in the stock, their average weight as mediated through metabolism and appetite, the water recirculation and waste treatment, hydroponic nutrient requirements and their loss functions. Six parameters, that is, water temperature, flow rate, stock density, feed ration size per fish, energy consumption rate and the quality of food (percentage of digestible proteins) are used to control the system under dynamic conditions. The time to harvest is treated as a static decision variable that is repeatedly adjusted to find the profit-maximizing solution. By modeling the complex interactions between the economic and biological systems, it is possible to obtain the most efficient decisions with respect to diet composition, feeding rates, harvesting time and nutrient releases. Some sample numerical results using data from a tilapia-tomato farm are presented and discussed.     

Relation between the endogenous antioxidant system and the quality of extra virgin olive oil under accelerated storage conditions

Three monovarietal extra virgin olive oils (EVOOs) were subjected to accelerated storage conditions (60 degrees C, dark) representative of the autoxidation process during shelf life. Oxidation markers, i.e., the peroxide value, conjugated dienes, the oil stability index, and minor components, were monitored. The changes in minor components, related to the stage of ongoing oxidation and expressed as a percentage of the induction period (IP), followed a similar pattern in all oils: o-diphenols diminished by the highest rate (halved within 15% of the IP), followed by alpha-tocopherol (halved within 35% of the IP). Carotenoids and chlorophylls were also affected by autoxidation, whereas squalene showed high stability (<20% loss within 100% of the IP). Polar phenols (especially o-diphenols) and alpha-tocopherol were deduced to be the most potent antioxidants of EVOO. They efficiently inhibited oxidative lipid deterioration and subsequent development of sensory defects (rancidity, discoloration), which occurred only after substantial depletion of these antioxidants. Therefore, they could also be used as markers for the oxidative status of EVOO particularly in the early stage of oxidation.     

<Emphasis Type="Italic">Turnip ringspot virus</Emphasis> recognised on Chinese cabbage in Russia

The nucleotide sequence of the 3′-terminal part of the RNA1 genome segment of the M12 isolate of comovirus Turnip ringspot virus (TuRSV) was established. This isolate originated in 1989 in Moscow (Russia) from Chinese cabbage with Radish mosaic virus-like symptoms. Comparison of the M12 RNA polymerase amino acid sequence with that of Radish mosaic virus (RaMV) revealed significant differences; these proteins are of different length and are only about 75% identical. On the other hand, the amino acid sequence of the M12 RNA polymerase was more than 94% identical with that of TuRSV recently described in Toledo (USA). We conclude that TuRSV occurs in Europe as well as in America and probably represents a new species of the genus Comovirus.     

Supplementation of plasma with olive oil phenols and extracts: influence on LDL oxidation

Phenols present in olive oil may contribute to the health effects of the Mediterranean lifestyle. Olive oil antioxidants increase the resistance of low-density lipoproteins (LDL) against oxidation in vitro, but human intervention studies have failed to demonstrate similar consistent effects. To better mimic the in vivo situation, plasma was incubated with either individual olive oil phenols or olive oil extracts with different phenolic compositions, and LDL was subsequently isolated and challenged for its resistance to oxidation. The results show that the ortho-dihydroxy phenols (hydroxytyrosol and oleuropein-aglycone) are more efficient than their mono-hydroxy counterparts (tyrosol and ligstroside-aglycone) in increasing the resistance of LDL to oxidation. However, the concentration of antioxidants required to inhibit LDL oxidation when added to whole plasma was substantially higher as compared to previous data where antioxidants are directly added to isolated LDL. In conclusion, this study supports the hypothesis that extra virgin olive oil phenols protect LDL in plasma against oxidation. The explanation that in vitro studies show protective effects in contrast to the lack of effect in the majority of human studies may be that the dose of the phenols and thus their plasma concentration in humans was too low to influence ex vivo LDL oxidizability. Further studies are required to gain a better understanding of the potential health benefits that extra virgin olive oil may provide.