Assimilation of dietary free amino acids,peptides and protein in post-larval Atlantic halibut (<Emphasis Type="Italic">Hippoglossus</Emphasis><Emphasis Type="Italic">hippoglossus</Emphasis>)

With the aim of improving the formulation of diets for early stages of marine fish, post-larval Hippoglossus hippoglossus (56 days after first feeding; 23 mg dry weight) were tube-fed liquid diets of radiolabelled L-(¹⁴C) free amino acids (FAA diet), peptides (PEPT diet) and protein (PROT diet), in order to compare the kinetics of transfer from gut into the liver and carcass. The test diets were prepared using equal concentrations of amino acids (AA) and fed as a single pulse (0.3 µl, 2.2 µg AA). The PROT diet consisted of methylated-¹⁴C-labelled (mainly lysine) bovine serum albumin (BSA), the PEPT diet was the PROT diet digested with trypsin and the FAA diet consisted of an amino acid mixture based on BSA composition with added ¹⁴C-lysine. The common labelling with ¹⁴C-lysine permitted a comparison of the three diets. Based on dissection and distribution of the tracer in each compartment, the FAA diet was almost completely absorbed 1 h after the tube-feeding; PEPT and PROT diets required more time before they were processed by the digestive tract. The FAA diet was absorbed about eight times as fast as protein and about six times as fast as peptides from the gut. A low retention of label in the liver for all diets at all sampling times suggests that the liver does not store the AA at these absorption rates. The FAA diet had a higher assimilation efficiency (about 90%) than the PEPT diet (about 12%) and PROT diet (about 32%). FAAs, thus, appear to be superior to protein and peptides as a dietary source of amino acids in post-larval Atlantic halibut.     

Chromium sorption on grape stalks encapsulated in calcium alginate beads

A novel sorbent based on 2% grape stalk wastes encapsulated in calcium alginate beads was investigated for the removal of Cr(VI) and Cr(III) from aqueous solutions. The sorbent proved to be efficient for chromium removal in both hexavalent and trivalent forms from aqueous solution at pH 3.0. In binary mixtures, the presence in solution of one of the forms enhances the sorption of the other which results in an increase of the amount of total chromium removed. This study suggests that the proposed sorbent can be used for the removal of chromium from wastewaters through a cost-effective and environmentally friendly process.     

On the gestation period of the blackfin reef shark,<Emphasis Type="Italic"> Carcharhinus melanopterus</Emphasis>, in waters off Moorea,French Polynesia

Underwater visual and photographic observations, over a four year period, monitored the presence of mating wounds on female blackfin reef shark, Carcharhinus melanopterus. Mating begins in November and continues until the end of March as each female follows her own temporal cycle. Correspondingly, parturition begins in September and continues until January. Each female again mates 1.5–2.5 months after parturition, thus completing an annual reproductive cycle. The gestation period is 286–305 days, with slight individual differences. All resident sharks under observation followed this pattern. Evidence of reproductive events presented by transient females conformed with the pattern of the residents.     

Seasonal growth and composition of fronds of Macrocystis pyrifera in the Falkland Islands

Frond growth of Macrocystis pyrifera in the Falkland Islands was monitored in shallow coastal water from December 1985 to March 1987, and at a different site in deeper water from December 1985 to June 1986. Growth rates in the deeper bed were generally higher than those recorded in the coastal zone. At both sites, node initiation and elongation rate fluctuated according to the seasonal pattern of light or water temperature. In the shallow coastal area, nitrate was abundant in the winter and below detection levels during late spring and summer. Correlation analysis suggests that the production of the fronds of the giant kelp in this area was probably inhibited during the summer months by extremely low concentrations of nutrients. Internal nitrogen was exhausted approximately one month after a sharp decline in ambient nitrate concentration, and carbon reserves were formed. In the deeper bed of M. pyrifera, nitrogen was abundant all year round and the production of the fronds reflected the seasonal pattern of light or water temperature. The nitrogen content of the tissue probably did not drop below a level that limited production, and no internal carbon reserves were accumulated.     

Lifting technique and abdominal belt usage: a biomechanical, physiological and subjective investigation

Some 10 male subjects carried out a repetitive lifting task for 15 min under four conditions on separate days. Subjects used either a squat lifting or a stoop lifting technique with or without an abdominal belt on each day. Measurements of spinal shrinkage, heart rate, perceived exertion and regional body pain were made under each condition. Although there was a significant difference in spinal shrinkage under all lifting conditions compared with shrinkage during 15 min of quiet standing (4.36 ± 2.24 vs. 1.13 ± 1.18 mm), there were no significant differences in shrinkage between the conditions. The subjects' heart rates were higher during the squat lift than the stoop lift (123 vs. 97 beats/min; p < 0.001). While the squat lift was perceived to be the safest lift by 90% of the subjects, 60% regarded this lift as the least preferred method (with or without the belt). Although all 10 subjects perceived the safest lifting method to involve the use of the belt, 50% rated the belt as their least preferred lifting condition. The findings cast doubt on the efficacy and acceptability of both abdominal belts and the practice of training workers in ‘safe’ lifting techniques and indicate that individual characteristics and preferences need to be considered when attempting to improve the safety of manual handling operations in industry.     

Injuries as a Result of California Earthquakes in the Past Decade

The devastating effects of earthquakes have been demonstrated repeatedly in the past decade, through moderate and major earthquakes such as the October 1987 Whittier Narrows earthquake (5.9 on the Richter scale), the October 1989 Loma Prieta earthquake (7.1) and the January 1994 Northridge earthquake (6.7). While 'official' tallies of injuries and deaths are reported for each event, the numbers vary from report to report. For Northridge, the number of injuries vary between 8,000 and 12,000; the number of deaths from 33 to 73 (Peek-Asa et al., 1997; Durkin, 1996).While official estimates are commonly reported following disasters, the study of actual numbers, types and causes of casualties has not developed. In this paper, we identify the numbers and risk factors for injuries within community-based samples across three earthquakes in urban California. We first report the numbers and types of injuries in each earthquake and then identify risk factors specifically associated with the Northridge earthquake     

Compositional Limitations in Poly–3–Hydroxyalkanoates Produced by Pseudomonas oleovorans

It is well known that Pseudomonas oleovorans can utilize sodium octanoate for both cell growth and the synthesis of polyhydroxyalkanoates (PHAs), but it can utilize sodium butyrate only for limited cell growth and not for the polyester formation when this substrate is the sole carbon source. Therefore, these two substrates were evaluated as cofeeds for the possible incorporation of 3-hydroxybutyryl groups in the resulting PHA. When sodium butyrate and sodium octanoate were fed to P. oleovorans as cosubstrates in various proportions, the resultant cell density and polymer content were proportional to the amount of sodium octanoate in the feed. The PHA extracted from cells grown in all combinations of these cosubstrates had similar unit compositions of approximately 8 mole % 3-hydroxyhexanoate, 91 mole % 3-hydroxyoctanoate and 1 mole % 3-hydroxydecanoate. 3-Hydroxybutyrate units were not detected in any of the PHAs isolated, indicating that these units could not be incorporated in the copolymer synthesized by P. oleovorans either because the cell did not synthesize that monomer or, if it did, the PHA synthase could not copolymerize it with the longer chain monomers.     

Use of Airborne Thermal Imagery to Detect and Monitor Inshore Oil Spill Residues During Darkness Hours

/ Trials were conducted using an airborne video system operating in the visible, near-infrared, and thermal wavelengths to detect two known oil spill releases during darkness at a distance of 10 nautical miles from the shore in St. Vincent's Gulf, South Australia. The oil spills consisted of two 20-liter samples released at 2-h intervals, one sample consisted of paraffinic neutral material and the other of automotive diesel oil. A tracking buoy was sent overboard in conjunction with the release of sample 1, and its movement monitored by satellite relay. Both oil residues were overflown by a light aircraft equipped with thermal, visible, and infrared imagers at a period of approximately 1 h after the release of the second oil residue. Trajectories of the oil residue releases were also modeled and the results compared to those obtained by the airborne video and the tracking buoy. Airborne imagery in the thermal wavelengths successfully located and mapped both oil residue samples during nighttime conditions. Results from the trial suggest that the most advantageous technique would be the combined use of the tracking beacon to obtain an approximate location of the oil spill and the airborne imagery to ascertain its extent and characteristics.KEY WORDS: Airborne video; Thermal imagery; Global positioning; Oil-spill monitoring; Tracking beacon     

Laboratory scale studies on removal of chromium from industrial wastes

Chromium being one of the major toxic pollutants is discharged from electroplating and chrome tanning processes and is also found in the effluents of dyes,paint pigments,manufacturing units etc.Chromium exists in aqueous systems in both trivalent(Cr^3 )and hexavalent (Cr^6 )forms.The hexavalent form is carcinogenic and toxic to aquatic life,whereas Cr^3 is however comparatively less toxic.This study was undertaken to investigate the total chromium removal from industial effluents by chemical means in order to achieve the Pakistan NEQS level of 1 mg/L by the methods of reduction and precipitation.The study was conducted in four phase Ⅰ,the optimum pH and cost effective reducing agent among the four popular commercial chemicals was selected.As a result,pH of 2 was found to be most suitable and sodium meta bisulfate was found to be the most cost effective reducing agent respectively.Phase Ⅱ showed that lower dose of sodium meta hisulfate was sufficient to obtain 100% efficiency in reducing Cr^6 to Cr^3 ,and it was noted that reaction time had no significance in the whole process.A design curve for reduction process was established which can act as a tool for treatment of industrial effluents.Phase Ⅲ studies indicated the best pH was 8.5 for precipitation of Cr^3 to chromium hydroxide by using lime.An efficiency of 100% was achievable and a settling time of 30 minutes produced clear effluent.Finally in Phase Ⅳ actual waste samples from chrome tanning and electroplating industries,when precipitated at pH of 12 gave 100% efficiency at a settling time of 30 minutes and confirmed that chemical means of reduction and precipitation is a feasible and viable solution for treating chromium wastes from industries.