Reef framework diagenesis across wave-flushed oxic-suboxic-anoxic transition zones

 The temporal and spatial variability of inorganic nutrient concentrations in overlying- and interstitial-seawater in Checker Reef, Oahu was examined for response to incident wave magnitude and direction. Well-point samplers were used to profile interstitial nutrient concentrations across oxic-suboxic-anoxic transition zones in the upper meter of the reef framework at four sites aligned across the patch reef. Samples were acquired over February, 1992, during which time dominant E-NE trade winds directed waves across the reef from the fore-reef to back-reef. However, W-SW “Kona” winds periodically interrupted this pattern and directed waves in the reverse direction. The interstitial microbial habitats of fore- and back-reef framework were distinct from those within the mid-reef framework. Maximum concentrations of PO₄, Si, and NH₄ in interstitial waters occurred at framework depths of 1–2 m, with the highest concentrations occuring within the mid-reef framework. Maximum concentrations of NO₃ and NO₂, which were used to delineate the core of the suboxic zone, occurred at framework depths of 5–10 cm at all stations and attained 2–4 fold higher peak concentrations within the mid-reef and back-reef than within the fore-reef. Variability in interstitial nutrient concentrations was greatest within the back-reef and is consistent with reversals of wave-direction, with the resultant increases in mixing between interstitial and overlying seawater due to flushing caused by the S-SW Kona wind events. The ratio of molar concentrations of total inorganic nitrogen to phosphate (TIN : PO₄) for the fore-reef was 5 : 1; while ratios for the mid- and back-reef were 13–15 : 1, reflecting that the dominant source of particulate organic matter to the fore-reef framework is plankton, while that of the mid- and back-reef is benthic reef plants. Accepted: 4 May 1999     

Different shell development in Mytilus galloprovincialis in 2 different populations from the Gulf of Naples

The size frequency distribution, the shell weight, the semilogarythmic growth, the carbonic anhydrase activity has been investigated between two populations of mussels from different sampling zones. Significative differences were found in the parameters investigated between the two populations. The authors conclude that the reason of this morphological and biochemical differences may arise from different natural hydrobiological factors and/or from different pollution of their habitat.     

Action of the unsaponifiable components of the most common edible oils on the growth of the alga Euglena gracilis. Preliminary studies

Within the sphere of the researches the biological effects of the most common edible oils (peanuts, sunflower, maize, soya and rectified olive) it has been studied the interaction between the development of the Euglena gracilis unicellular seaweed and the presence of the unsaponifiables examined in their cultures. As a biologically active substance it has been used 3,4-benzopyrene. Spectrophotometric analysis have evidenced that all the unsaponifiables, especially those of the soya seeds, caused a growth decrease of the seaweed culture. A similar effect is found in the cultures treated with aromatic hydrocarbon.     

Destruction of cyanogen bromide and inorganic cyanides

Cyanogen bromide in water and seven organic solvents and sodium cyanide in water may safely and efficiently (greater than 99.7%) be destroyed using sodium hydroxide (1 M) solution and commercially available sodium or calcium hypochlorite. Details are given of an analytical procedure which can be used to check the final reaction mixture for the presence of residual cyanogen bromide or cyanide.     

Interaction between alkaloids of Claviceps purpurea and development of some bacteria and bacteriophages. Preliminary experiments]

It has been tested the bacteriolytic activity and the interaction among the development of the bacteriophage T4 and Ergot alkaloids. It has been determined a bacteriolytic action on the bacterial stub "E. Coli host of bacteriophage T4. It exist an interaction also among such alkaloids and the development of the bacteriophage T4, which appears through an increase of the quantity of lysis areas, becoming evident in solid bodies containing the lysing bacterium. Further researches with other bacterial and virus stubs will be effected and mentioned afterward.     

Quantitative Detection of Epstein-Barr Virus DNA in Cerebrospinal Fluid and Blood Samples of Patients with Relapsing-Remitting Multiple Sclerosis

The presence of Epstein-Barr Virus (EBV) DNA in cerebrospinal fluid (CSF) and peripheral blood (PB) samples collected from 55 patients with clinical and radiologically-active relapsing-remitting MS (RRMS) and 51 subjects with other neurological diseases was determined using standardized commercially available kits for viral nucleic acid extraction and quantitative EBV DNA detection. Both cell-free and cell-associated CSF and PB fractions were analyzed, to distinguish latent from lytic EBV infection. EBV DNA was detected in 5.5% and 18.2% of cell-free and cell-associated CSF fractions of patients with RRMS as compared to 7.8% and 7.8% of controls; plasma and peripheral blood mononuclear cells (PBMC) positivity rates were 7.3% and 47.3% versus 5.8% and 31.4%, respectively. No significant difference in median EBV viral loads of positive samples was found between RRMS and control patients in all tested samples. Absence of statistically significant differences in EBV positivity rates between RRMS and control patients, despite the use of highly sensitive standardized methods, points to the lack of association between EBV and MS disease activity.     

Shallow pore water sampling in reef sediments

Several new techniques have been developed to allow the geochemical characterization of shallow pore waters in reefs. First, a new method was developed for using non-metallic well-points to sample pore waters from shallow depths (<1 m) in coral reefs with unconsolidated substrates. These PVC well-points can be made faster and at less expense than well-points made of stainless steel. They also eliminate metal contamination and are free from the problems of corrosion in sea water. Additional improvements in sampling techniques maximize the spatial resolution of geochemical gradients and address the problems of atmospheric contamination associated with the sampling of dissolved gases. Data taken from Checker Reef, Oahu, Hawaii, illustrate the application of these methods. Accepted: 1 December 1999