Quantification of diel vertical migration by micronektonic taxa in the northeast Atlantic

Analyses of day/night changes in the bathymetric distribution of micronektonic biomass at 16 stations in the northeastern Atlantic, sampled between 1978 and 1994, provided quantitative estimates of the organic carbon fluxes associated with diel vertical migration of individual taxa of micronekton. Gelatinous taxa contributed 50–80% of the integrated standing crop by volume but, apart from tunicates, contributed relatively little to the active migratory fluxes when expressed in terms of carbon. Total micronektonic migratory fluxes into the upper 200 m ranged from 12.5 to 58 mgC per m². At 15 stations, fish and pteropods provided 50–80% of the fluxes into the upper 100, 200 and 400 m. At one station, tunicates (pyrosomes) contributed substantially. Wherever tunicates or the medusa Pelagia were swarming, migrations by other taxa appear to be suppressed. The mean proportions of the stock (in terms of biomass) of each of the dominant migratory taxa entering and leaving the upper 100 m were 23% for tunicates, 18% for fish, 22% for pteropods, 8% for decapod crustaceans and 23% for euphausiids. The maximum proportions for these five taxa were 90%, 60%, 75%, 25% and 75%, respectively. Similar estimates of the mean fluxes into and out of the upper 400 m were generally higher: 19% for tunicates, 39% for fish, 28% for pteropods, 49% for decapods and 55% for euphausiids; the respective maxima were 99%, 74%, 99%, 72% and 91%. It is estimated for fish that if these migrations occur throughout the year, they will result in an active carbon export (both POC and DOC) from the wind-mixed layer and immediate sub-thermocline depths of about 500% of the mean annual standing stock. If this estimate can be extended to other taxa, then the material fluxes resulting from these active migrations will be quantitatively similar to those resulting from the deposition of phytodetritus at temperate latitudes.     

The vertical distribution of the British intertidal Acari—the non halacarid fauna (Arachnida: Acari)

The vertical distribution of the non halacarid littoral Acari on rocky shores was examined. The habitat of these Acari was investigated and compared with that of the Halacaridae. Some physiological factors were investigated to explain this distribution. Three ecologically distinct life styles were recognized among these Acari.     

Keratinophilic fungi from Nigerian soil

During a survey of keratinophilic fungi in Nigerian soil samples, twelve species of fungi were isolated. These included Chrysosporium keratinophilum, C. tropicum, Curvularia lunata, Microsporum audouinii, M. canis, M. fulvum, M. gypseum, M. vanbreuseghemii, Trichophyton ajelloi, T. mentagrophytes, T. soudanense and T. yaoundei. These keratinophilic fungi had a higher incidence by occurrence of individual species during the rainy season (May–October) than the dry season (November–April).     

Thermophilous fungi of birds' nests

Summary Twenty seven species of thermophilous fungi were found on plant debris in the nests of twelve passerine bird species in Nottinghamshire of whichDactylomyces thermophilus, Humicola insolens, Penicillium duponti, Stilbella thermophila andTorula thermophila are new records for Britain.Certain species, such asAspergillus fumigatus, Chaetomium thermophile, Coprinus delicatulus, Humicola insolens, Thermoidium sulphureum andThermomyces languinosus were present in most of the 54 nests surveyed, usually at a high frequency.The species populations of thermophilous nest fungi are similar to those on plant debris on the soil surface and in the grassland vegetation. They are closely related to thermophilous floras known from various composts. The relatively high frequency of strictly thermophilic species found on organic debris of the various nests indicates that nests are warmed up by the birds while using the nests, and, probably, also by the sun and air during the summer months.The number of thermophilous species and their frequency on the plant debris of the nests varies considerably in the twelve bird species. The number of species as well as their frequency was exceptionally low in Sandmartin's nests but the nests of Blackbird, Hedge Sparrow and of the Thrushes were rich in thermophilous fungi.All the 27 thermophilous fungi recorded from the birds' nests may be regarded a) as saprophytes with no known harmful relationships to birds and other animals, such asAllescheria terrestris, Botryotrichum species,Chaetomium thermophile, Coprinus delicatulus, Humicola insolens, Penicillium duponti, Sporotrichum thermophile, Stilbella thermophila, Thermoidium sulphureum, Thielavia sepedonium andTorula thermophila, or b) as saprophytes on the plant debris of the nests but with known potential pathogenicity to birds, other animals and man, e.g.,Absidia ramosa, Aspergillus fumigatus, A. terreus, Dendrostilbella boydii (=conidialAllescheria boydii),Emericella nidulans, Endomyces lactis, Mucor pusillus, Paecilomyces varioti, Rhizopus arrhizus, R. cohnii andThermomyces lanuginosus.     

Discrepancies between flow cytometric and cytogenetic studies in the detection of aneuploidy in human solid tumors

Parallel flow cytometric (FCM) cell DNA studies and cytogenetic studies were performed on clinical samples from twenty human solid tumors of various types and on cell lines established in tissue culture from three of these tumors. Six of twenty clinical samples (30%) showed concordance between flow cytometry and cytogenetics with respect to the presence or absence of aneuploidy. Among the fourteen cases with discrepancies between the two methods, 8 (40% of all cases) showed hypodiploidy by cytogenetics and had diploid DNA histograms. Three cases (15%) had prominent discrete peaks in the triploid to tetraploid region by cytogenetics but had only barely discernible corresponding peaks in the DNA histogram. In two cases (10%) cytogenetic studies revealed diffuse aneuploidy. Cytogenetic studies demonstrated near-tetraploidy in three samples, but only one of these was detected by FCM; all three cases exhibited other numerical chromosomal abnormalities. In one case aneuploidy was demonstrated by FCM and not by cytogenetics. Among the tumor cell lines established in culture, the DNA Index was often higher than the cytogenetic index. Overall, 13/20 or 65% of patients with solid tumors in this study had numerical chromosomal abnormalities that were not detected by flow cytometry. Eleven of these patients had distant metastases at the time of tumor sampling, and nine of these died of their disease within 1-11 months of the time of study.