Genetic Diversity in the Endangered Lily Harperocallis flava and a Close Relative, Tofieldia racemosa

We examined genetic diversity in 464 individuals of the monotypic lily Harperocallis flava in its two habitats (seepage bogs and a roadside right-of-way) and five populations of a co-occurring related lily, Tofieldia racemosa. The endangered H. flava, endemic to the Apalachicola lowlands of the Florida panhandle, was monomorphic for the 22 loci scored. In contrast, T. racemosa had a high proportion of polymorphic loci ( P_s = 68.2%; P_p = 47.7%) with moderate genetic diversity (   H_es = 0.134; H_ep = 0.114). Estimated gene flow was moderately high ( Nm = 2.07) for T. racemosa, with most (93%) of the total genetic diversity found within populations. Despite the low level of genetic divergence, some isolation by distance was detected among T. racemosa populations. Harperocallis flava and other species without discernable genetic variation pose special problems for conservation biologists because genetic criteria are not available for the development of ex situ and in situ conservation and management strategies.     

Histochemical and ultrastructural characterisation of mantle storage cells in the hydrothermal-vent bivalve Bathymodiolus azoricus

This study reports on two types of storage cells that are present in the mantle connective tissue of the deep-sea mussel Bathymodiolus azoricus. One type corresponds to the adipogranular cells, a kind of storage cell previously described in other bivalves. In these cells extensive regions of the cytoplasm are filled with glycogen deposits and these zones became strongly stained after histochemical (PAS) or ultrastructural detection of polysaccharides. Several lipid droplets and membrane bound granules containing homogeneous electron-dense material are also present in adipogranular cells. A second type of cell contains large lysosomes in addition to numerous lipid droplets, but lacking cytoplasmic glycogen deposits. Due to these characteristics we named them adipolysosomal cells. They can be identified in semi-thin sections stained with PAS reaction because the lysosomes are the only positively stained structures. In the connective tissue of the mantle, some cells containing many lysosomes and a few lipid droplets were also observed. These cells differ from the adipolysosomal cells mainly because they have a reduced amount of lipid reserves, and could be an initial stage in the development of adipolysosomal cells. The vesicular connective tissue cells that in other Mytilidae are specialised in glycogen storage were not detected in B. azoricus. The reserves accumulated in the two types of storage cells described in B. azoricus may be important for the survival of these hydrothermal-vent bivalves if their nutrition is affected by a temporary loss or reduction of endosymbiotic bacteria due to sulphide and/or methane shortage caused by oscillations in vent activity.     

Foraging activity and resource use by three parrotfish species at Fernando de Noronha Archipelago, tropical West Atlantic

Parrotfishes are important components of the herbivore and detritivore guilds of tropical and subtropical reefs. Most of parrotfish species are protogynous hermaphrodites that change colour and sex, from initial phase females or males (IP) to terminal phase males (TP). We studied the foraging behaviour of Sparisoma amplum, S. axillare and S. frondosum, three syntopic scarids on the rocky reefs of Fernando de Noronha Archipelago, Tropical West Atlantic. The three parrotfish species differed in food selection and preference, but IP and TP individuals of the same species preferred the same food types, except for S. amplum. Feeding rates of IP individuals were higher than those of TP individuals, but the distribution of feeding frequencies throughout the day of IP and TP individuals of the same species was similar. IP individuals had higher feeding rates than TP ones, which seems related to the fact that TP individuals spend a large amount of time patrolling their territories and chasing away conspecific individuals at the study site. The general foraging pattern we found for S. amplum, S. axillare and S. frondosum is similar to patterns found for other parrotfish species in the Western Atlantic.     

Influence of ash on the fiber composition of dried dairy manures

The objective of this work was to examine the role of ash in the compositional analysis of dried dairy manures. Ninety-nine dairy manures obtained from Connecticut, Maryland, New York, Pennsylvania and Virginia were dried at 60 degrees C, and ground to 20 mesh. Samples were analyzed for neutral and acid detergent fiber, acid detergent lignin, total carbon, total nitrogen, and ash. In addition, cellulose and hemicellulose were computed by difference. Results indicated that high ash contents (8-52% of dry matter) can dramatically and unpredictably alter various measures of fiber composition and are a significant source of error in the determination of manure composition and how it relates to mineralization or other compositional influenced factors. Also, while the ash content of the dried intact manure can easily be determined, it is difficult to estimate the ash contribution to the individual fiber determinations, especially if sequential assays are performed.     

Assessing microbial communities for a metabolic profile similar to activated sludge.

To search for reliable testing inocula alternatives to activated sludge cultures, several model microbial consortia were compared with activated sludge populations for their functional diversity. The evaluation of the metabolic potential of these mixed inocula was performed using the Biolog EcoPlates and GN and GP MicroPlates (Biolog, Inc., Hayward, California). The community-level physiological profiles (CLPPs) obtained for model communities and activated sludge samples were analyzed by principal component analysis and hierarchic clustering methods, to evaluate the ability of Biolog plates to distinguish among the different microbial communities. The effect of different inocula preparation methodologies on the community structure was also studied. The CLPPs obtained with EcoPlates and GN MicroPlates showed that EcoPlates are suitable to screen communities with a metabolic profile similar to activated sludge. New, well-defined, standardized, and safe inocula presenting the same metabolic community profile as activated sludge were selected and can be tested as surrogate cultures in activated-sludge-based bioassays.     

Liquid chromatography-hydride generation-atomic absorption spectrometry for the speciation of tin in seafoods

Liquid chromatography with hydride generation atomic absorption spectrometry as the detection system was applied to the separation and determination of inorganic tin, tributyltin, dibutyltin, monobutyltin, diphenyltin and monophenyltin. A reversed phase C18 column and a methanol/water/acetic acid (70:27:3, v/v/v) mixture containing 0.05%(v/v) triethylamine and 0.1%(w/v) tropolone as the mobile phase (isocratic elution) were used. Extraction of organotins from the samples was carried out using methanol containing 0.05%(w/v) tropolone, a process that was repeated twice. The supernatants were shaken with water and dichloromethane in a separating funnel and the organic phase was collected and evaporated to dryness. When the method was applied to the speciation of tin in fresh and canned mussels, no organotins above the detection limits were identified in any of the samples, inorganic tin being the only species detected. The reliability of the procedure was checked by analyzing the total tin content of the samples by electrothermal atomic absorption spectrometry and by speciation of tin in a certified reference material, mussel tissue (CRM 477). The method can be used for environmental monitoring of organotins contaminated samples.     

Evaluation of CO exposure in active smokers while smoking using breath analysis technique

The current study evaluated the personal CO exposure of active smokers while smoking under controlled conditions, decay rate of CO in the body following active smoking, and CO accumulation in the body from repeated active smoking using a novel device for the direct measurement of alveolar breath CO. Prior to this evaluation, the proposed alveolar CO measurement device was successfully evaluated as regards the effect of humidity, CO recovery, carryover effect, and in comparison with the bag sampling method. The breath concentrations prior to and after a single cigarette were measured using a repeated measure design. Under the controlled conditions employed in the present study, active smoking was found to cause a significant body burden of CO. The post-exposure breath CO level was 1.6-2.0 times higher than the background breath level, depending on the subject and cigarette brand. In addition, the pre- and post-exposure breath concentrations were both significantly different among the subjects, yet the ratios of post-exposure to pre-exposure breath concentrations did not differ significantly between the different cigarette brands. The time-series alveolar breath concentrations measured following active smoking showed that the post-exposure alveolar CO concentrations decreased slowly even in the early phase of the decay curves, indicating a mono-compartment uptake and elimination model for the human body. The half-lives estimated in the present study (301, 315, and 385 min) were longer than or comparable to those in previous studies. The breath measurements prior to and after repeated active smoking exhibited a significant increasing trend for both the pre- and post-exposure concentrations. The changes in the pre- and post-exposure breath CO concentrations with repeated smoking ranged from 7% to 23% and from 10% to 15%, respectively, with half-hour intervals between cigarettes, and from 4% to 11% and from 6% to 8%, respectively, with hour intervals between cigarettes. Accordingly, most of the current results indicated that CO was accumulated in the human body with repeated active smoking.     

Determination of aliphatic and polycyclic aromatic hydrocarbons in atmospheric particulate samples of a coruña city (Spain)

The hydrocarbon composition of atmospheric particulate matter from A Coruña city (Northwest Spain) has been studied. TSP (total suspended particulate) and PM₁₀ (particulate matter with aerodynamic diameter <10 µm) samples were taken over 7 and 4 months at two stations located in residential and industrial sectors of A Coruña city, respectively. The levels of hydrocarbons found in atmospheric particulate samples of A Coruña city are higher than the ones found in other cities over the world. Ratios between the analysed compounds and their sources were established. Both anthropogenic and biogenic origins were found.     

Priority volatile organic compounds in surface waters of the southern North Sea

The occurrence of 25 volatile organic compounds (VOCs) was studied from April 1998 to October 2000 in the southern North Sea. Target VOCs were selected from lists of priority pollutants for the marine environment and included, e.g., chlorinated short-chain hydrocarbons (CHCs), monocyclic aromatic hydrocarbons (MAHs), and chlorinated monocyclic aromatic hydrocarbons (CMAHs). Water samples were taken from the Channel, the Belgian Continental Shelf, the mouth of the Scheldt estuary and the Southern Bight, and were analysed by purge-and-trap and high-resolution gas chromatography-mass spectrometry. All data were produced by analyses deemed 'in control' by a rigorous quality assurance/quality control program provided by QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe). Chloroform and trichloroethene were commonly detected at concentrations up to 1900 and 270 ng l(-1), respectively. The other CHCs were generally found below 5 ng l(-1), and rarely exceeded 10 ng l(-1). Concentrations of MAHs were at least one order of magnitude higher than those of the CHCs. The higher levels were attributed to anthropogenic emissions from oil-related activities in coastal areas. CMAHs, except chlorobenzene and 1,4-dichlorobenzene, were hardly detected in North Sea waters. The levels of several CHCs and MAHs were shown to decrease compared to previous investigations in 1994-1995, probably as a result of on-going emission reduction efforts. The occurrence of 1,1,1-trichloroethane, for instance, was substantially reduced since the Montreal Protocol was implemented in 1995.     

Survival of brown trout during spring flood in DOC-rich streams in northern Sweden: the effect of present acid deposition and modelled pre-industrial water quality

Mortality and physiological responses in brown trout (Salmo trutta) were studied during spring snow melt in six streams in northern Sweden that differed in concentrations of dissolved organic carbon (DOC) and pH declines. Data from these streams were used to create an empirical model for predicting fish responses (mortality and physiological disturbances) in DOC-rich streams using readily accessible water chemistry parameters. The results suggest that fish in these systems can tolerate higher acidity and inorganic aluminium levels than fish in low DOC streams. But even with the relatively low contemporary deposition load, anthropogenic deposition can cause fish mortality in the most acid-sensitive surface waters in northern Sweden during spring flood. However, the results suggests that it is only in streams with high levels of organically complexed aluminium in combination with a natural pH decline to below 5.0 during the spring where current sulphur deposition can cause irreversible damage to brown trout in the region. This study support earlier studies suggesting that DOC has an ameliorating effect on physiological disturbances in humic waters but the study also shows that surviving fish recover physiologically when the water quality returns to less toxic conditions following a toxic high flow period. The physiological response under natural, pre-industrial conditions was also estimated.