Glycosylation of human LDL and its metabolism in human skin fibroblasts

Extrachromosomal DNA of heterogeneous size has been isolated from bursal lymphocytes and splenocytes of five week old chickens, and from splenocytes of mice. This DNA contains covalently closed circles, open circles, and open circles with tails. Open circular molecules with and without tails are more frequent than covalently closed species, and the total number of small circular DNA molecules per cell is in the range of 100–200 copies.     

Social development in nursery-reared pigtailed macaques (Macaca nemestrina)

The social development of 240 nursery-reared pigtailed macaques (Macaca nemestrina) was studied from postnatal weeks 4 to 32. The objectives of the study were to document developmental trends and evaluate social behavior in laboratory-reared M. nemestrina raised at the University of Washington Infant Primate Laboratory, and to identify husbandry factors that might affect early social development. Only infants who had not undergone invasive postnatal experimental manipulation and had no chronic illness or injuries were included in the study. Infants were separated from their mothers and housed singly, but had access to peers for 30 min a day, 5 days a week, in a large playroom. Play and social behaviors emerged early in development, increased during the developmental period studied and occupied a large portion of the infants' time budgets. Although disturbance behaviors occurred with some frequency and duration early in development, they occupied a very small portion of the infants' time budget at 8 months of age. Weaning from infant formula at 16–19 weeks retarded development of play behavior. Permanent removal of a cloth comforter (diaper) during weeks 20–24 had no long-term behavioral effects. It was concluded that at 8 months of age these infants showed relatively normal species-typical behavioral repertoires. Am J Primatol 41:23–35, 1997. © 1997 Wiley-Liss, Inc.     

Diet and food partitioning between juveniles of mutton Lutjanus analis,dog Lutjanus jocu and lane Lutjanus synagris snappers (Perciformes: Lutjanidae) in a mangrove‐fringed estuarine environment

Diet of juvenile mutton Lutjanus analis, dog Lutjanus jocu and lane Lutjanus synagris snappers were studied in the tropical Brazilian estuarine system of the Piraquê‐açú and Piraquê‐mirim Rivers to determine how these species share the resources in this restricted space. The three species prey principally upon Peracarida (L. synagris: relative importance index I_RIc = 29%), Natantia (L. analis and L. synagris: I_RIc = 39 and 38%, respectively), Reptantia (L. analis and L. jocu: I_RIc = 28 and 43%, respectively) and Teleostei (L. jocu: I_RIc = 24%). The three species use estuaries as nursery habitats but food overlap was not biologically significant due to a combination of interspecific differences in size, spatial distribution, microhabitat preferences and seasonal patterns of abundance and prey choice. Large marine protected areas incorporating essential habitats for all life stages are suggested to be the best tool for the management of these economically important species.     

Changes in Eucalyptus camaldulensis essential oil composition as response to drought preconditioning

Abstract

Water deficit, a common constraint in forestry, is the main cause of plant stress during plantation. The survival and growth of seedlings is also compromised by herbivory during establishment. The potential of nursery preconditioning to enhance survival chances of future trees by reducing palatability or attracting beneficial insects as a result of changes in chemical defences may be an answer to overcome this situation. Changes in essential oil production and composition were evaluated by GC and GC-MS in Eucalytus camaldulensis seedlings submitted to drought during four weeks at the last stage of nursery period (20 weeks). Significant changes in essential oil relative composition were found. Seedlings (young leaves) submitted to drought developed a terpenoid blend, which has been previously associated to mature leaves and related to their higher resistance towards herbivory. Total amount of non-oxygenated terpenes decreased by 44%, whereas some oxygenated sesquiterpenes (globulol, epiglobulol and ledol) were doubled, and 1,8-cineole content was enhanced by 28.3%.     

Control of Otiorhynchus sulcatus (Fabricius) (Coleoptera: Curculionidae) Larvae on a Range of Hardy Ornamental Nursery Stock Species Using the Entomogenous Fungus Metarhizium anisopliae

The potential of the entomogenous fungus Metarhizium anisopliae as a microbial control agent for vine weevil (Otiorhynchus sulcatus) larvae was examined on a range of outdoor hardy nursery stock species. A curative application of M. anisopliae conidia (5× 10⁸ conidia l^‐1compost) reduced larval numbers by 62% on Skimmia japonica ’Rubella’ and by up to 43% on Viburnum plicatum ’Mariesii’. Four M. anisopliae isolates were examined and all reduced the larval populations on both species. However, the reductions were only significant with strains 159–83 and 100–82 on S. japonica ’Rubella’ and 100–82 on V. plicatum ’Mariesii’. Larval development on two other species (Hydrangea macrophylla ’Blue Wave’ and Thuja plicata ’Zebrina') which had been treated with 0.05% Triton X‐100 (the control treatment) was very poor and therefore it was not possible to determine whether or not the fungal drench had any effect. The experiment was repeated in the following year at two different sites, East Mailing and Littlehampton, using a prophylactic drench of two M. anisopliae isolates on a greater number of plant species. Strain 275–86 was more effective than 159–83 on all species at East Mailing, with the exception of V. davidii. The difference was less pronounced at Littlehampton and the results from the two isolates were similar. Larval control was highly variable and species dependent with a reduction in larval numbers ranging from zero to 96% and zero to 90% at East Mailing and Littlehampton respectively. The larval populations in pots treated with Triton X‐100 were also highly variable, ranging from zero (Chaemaecyparis lawsoniana ’Stardust’ Dianthus ’Maria’ Escallonia ’Crimson Spire’ and Pittosporum tenuifolium ’Gamettii') to 17.8 larvae per pot (Ribes nigrum ’Baldwin ‘). The results indicate the potential of M. anisopliae and demonstrate the complexity of plant‐weevil‐fungus interactions.     

Differential responses of three fungal species to environmental factors and their role in the mycorrhization of<Emphasis Type="Italic"> Pinus radiata</Emphasis> D. Don

Three ectomycorrhizal (ECM) isolates of Rhizopogon luteolus, R. roseolus and Scleroderma citrinum were found to differ markedly in their in vitro tolerance to adverse conditions limiting fungal growth, i.e. water availability, pH and heavy metal pollution. S. citrinum was the most sensitive, R. luteolus intermediate and R. roseolus the most tolerant species. Pinus radiata D. Don seedlings were inoculated in the laboratory and in a containerised seedling nursery with spore suspensions of the three ECM species. Colonisation percentage was considerably lower under nursery conditions, probably due to competition by native fungi. The effects of nursery ECM inoculation on seedling growth depended on the fungal species. Only R. roseolus-colonised plants showed a significantly higher shoot growth than non-mycorrhizal plants. All three fungi induced significantly higher root dry weights relative to control plants. Despite the low mycorrhizal colonisation, mycorrhization with all three species improved the physiological status of nursery-grown seedlings, e.g. enhanced root enzyme activity, shoot nutrient and pigment content, net photosynthesis rate and water use efficiency. Of the three fungal species, R. roseolus was the most effective; this species was also the most adaptable and showed the greatest range of tolerance to adverse environmental conditions in pure culture. It is, therefore, proposed as a promising fungal species for ECM inoculation of P. radiata in the nursery.     

Seasonal Variation of Ichthyoplankton in a Western Caribbean Bay System

The plankton of Bahia de la Ascension was sampled monthly, from August 1990 to July 1991, to ascertain ichthyoplankton composition, abundance, and seasonality. These data were used to assess the inferred function of the bay as spawning and nursery grounds. Fifty-one families, 66 genera, and 53 species of fish embryos and larvae were identified. Engraulidae, Clupeidae, Labrisomidae, Callionymidae, Gerreidae, and Gobiidae comprised 81.5% of the larvae captured: the remaining 18.5% included several coral reef fish families. Greatest mean fish egg densities were recorded between December and April, 341–246 per 100m³, suggesting a major spawning period. The monthly mean density of total fish embryos and larvae showed two peaks: one in late dry season (June), dominated by newly hatched engraulid, and a second (December) during the cold-front season with high densities of preflexion labrisomid and engraulid embryos. When labrisomid and engraulid embryos and larvae were excluded, densities peaked in the rainy season (July to October). Gerreidae and Callionymidae were significantly more abundant in the rainy season, while Labrisomidae and Gobiidae in the cold-front season. The highest embryos and larvae richness was observed in August during the rainy season with mean value significatively greater than those from cold-front and dry seasons. The occurrence of high egg densities and the wide range of embryos and larva stages are evidences that Bahia de la Ascension is a regionally important spawning and nursery ground for marine fish. Because this study covered partially the marine ecosystem of Bahia de la Ascension using convential gear, we suggest to conduct further research for have a full understanding of the importance of this bay for fish recruitment.     

Cloning of the DNA repair genes mtcA, mtcB, uvsC, uvsD, uvsE and the leuB gene from Deinococcus radiodurans

A gene library from Deinococcus radiodurans has been constructed in the cosmid pJBFH. A 51.5-kb hybrid cosmid, pUE40, that transduced Escherichia coli HB101 from leucine dependence to independence was selected, and a 6.9-kb fragment which carried the leuB gene from D. radiodurans was subcloned into the EcoRI site of pAT153. The DNA repair genes mtcA, mtcB, uvsC, uvsD and uvsE, which code for two D. radiodurans UV endonucleases were identified by transforming appropriate repair-deficient mutants of D. radiodurans to repair proficiency with DNA derived from the gene library. Hybrid cosmid pUE50 (37.9 kb) containing an insert carrying both the mtcA and mtcB genes was selected and 5.6- and 2.7-kb DNA fragments carrying mtcA and mtcB, respectively, i.e., the genes that code for UV endonuclease alpha, were subcloned into the EcoRI site of pAT153. The three genes uvsC, uvsD and uvsE, that code for UV endonuclease beta, were all present in the 46.0-kb hybrid cosmid pUE60. The uvsE gene in a 12.2-kb fragment was subcloned into the HindIII site of pAT153 and the size of the insert reduced to 6.1 kb by deletion of a 6.7-kb fragment from the hybrid plasmid pUE62. None of the uvs genes introduced into the UV-sensitive E. coli CSR603 (uvrA-) was able to complement its repair defect. The mtcA, uvsC, uvsD and uvsE genes were found in the 52.5-kb hybrid cosmid pUE70. It is concluded that the DNA repair genes mtcA, mtcB, uvsC, uvsD and uvsE are located within an 83.0-kb fragment of the D. radiodurans genome.     

Assessment of suitability and suppressiveness of on-farm green compost as a substitute of peat in the production of lavender plants

Suppression of root rot diseases of ornamental plants is a potential benefit of formulating soilless container media with compost. A green compost (green nursery compost, GNC), obtained by a circular-economy approach from residues of pruning of woody plants and grass clippings during the nursery activities was analysed for its suppressiveness of root rot diseases using lavender. To this end, a bioassay was develop by formulating potting mixes containing GNC with two rates of peat substitution (25% and 50%) and infested with the root rot pathogens Sclerotinia sclerotiorum, Rhizoctonia solani and Phytophthora nicotianae. Contrasting results were obtained by using both substrates with a significant reduction of root rot by S. sclerotiorum, no effect on the containment of that by P. nicotianae, and an increase of symptoms caused by R. solani. The specific suppressiveness observed may be attributed to the colonisation of compost by specific groups of antagonistic microorganisms. This hypothesis was investigated by the analysis of culturable fungal community, which resulted in the isolation of Trichoderma harzianum and T. atroviride as preponderant fungal species. Trichoderma representative isolates exerted in vitro antagonistic activities against the target pathogens with varying efficiencies indicating the employment of multiple complementary mechanisms, which may have contributed to the observed specific suppressiveness. Both substrates containing GNC resulted suitable for nursery cultivation of lavender, showing a growth performance similar to that obtained with peat-based substrate. Present results indicate that on-farm compost is a suitable component of mixed-peat substrates capable to support plant growth and provide specific disease suppression.     

A life in the surf zone: Age and feeding habits of the pompano (Trachinotus ovatus,Linnaeus, 1758) on the beaches of the Gulf of Cádiz (south-west Iberian Peninsula)

Surf zones are crucial habitats for many fish species, where they spend the initial stages of their lives, finding food and shelter. One such species is the pompano (Trachinotus ovatus). The aim of this study was to examine the age and diet of the pompano within the surf zone, along with any potential variations in the environment. The average size of the specimens was 10.61 ± 4.91 cm. The length–weight relationship was total weight (TW) = 0.0136*total length (TL)^2.8512 (parameter a: 95% C.I. : 0.0130–0.0142 and parameter b: 95% C.I. : 2.8318–2.8705). The most abundant age classes were 0+ and 1+, making up 97% of the captured specimens, with significant differences in the abundance of age classes depending on the time of the day and season. The pompano primarily fed on clupeiforms, copepods, and mysids, with significant variations in diet based on the time of the day, season, and size of the specimens. This study contributes new information about the use of the surf zone by T. ovatus in its early years of life, underscoring the importance of these areas and their role as an additional ecosystem service.