Dynamic stoichiometric response to food quality fluctuations in the heterotrophic dinoflagellate Oxyrrhis marina

With respect to nutrients, plants are rather non-homoeostatic while most metazoans have much more confined ranges of nutrient ratios. It was recently highlighted that the homoeostatic ability of microzooplankters lies in between these two extremes. Nevertheless, we know very little on the dynamics of stoichiometric changes. Hence, we investigated how the stoichiometry of the heterotrophic dinoflagellate Oxyrrhis marina is affected (1) during a starvation period and (2) when fed nutrient deplete Rhodomonas salina after having been pre-conditioned on nutrient replete algae and vice versa. We observed that the dinoflagellate was able to maintain its N:P ratio constant over 78 h of starvation. We inferred that under starvation, nitrogen-limited O. marina mainly used fat as energy source while nitrogen-rich individuals also used proteins as fuel in cellular respiration. Further, we showed that O. marina presents resistance to nutrient limitation, with stronger regulation against P-limitation than against N-limitation. This resilience in microzooplankton stoichiometry following food quality stress would have great implications for both top-down (nutrient remineralisation) and bottom-up controls (quality as food).     

Prenatal obstruction of the ileum diagnosed by ultrasound

A case of low atresia of the ileum, diagnosed prenatally by real-time ultrasound scanning, is presented. The ultrasound examination showed progressive distension of intestinal loops, with strong peristaltic movements. The stomach was also distended, presenting as a large cystic area in the upper left abdomen. Real-time ultrasound technique is most advantageous in the diagnosis of fetal ileus. Prenatal diagnosis of fetal intestinal obstruction is of great importance, making early and safe treatment of the newborn possible.     

The art of measuring nothing: The paradox of measuring safety in a changing civil aviation industry using traditional safety metrics

Measuring safety as an outcome variable within the ultra-safe civil aviation industry during periods of deliberate organizational change is a difficult, and often fruitless, task. Anticipating eroding safety processes, based on measuring nothing happening over time, does not adequately capture the true state of an evolving safe system, and this is particularly relevant for leaders and managers in a civil aviation industry responsible for maintaining and improving ultra-safe performance while simultaneously managing demanding strategic business goals.In this paper, I will look at the difficulties of measuring safety as an outcome measure in high reliability organizations (HROs) using the traditional measures of incident and accident reporting during periods of deliberate organizational change inspired by the results from a 3 year longitudinal case study of the Norwegian Air Navigation Services provider – Avinor. I will first review the current safety literature relating to safety management systems (SMSs) used in the civil aviation industry. I will then propose a more holistic model that shifts the focus from the traditional safety monitoring mechanisms of risk analysis and trial and error learning, to the natural interactivity within socio-technical systems as found in high reliability organizations. And finally, I will present a summary of the empirical results of an alternate methodology for measuring perceived changes in safety at the operational level as leading indicators of evolving safety at the organizational level.     

The Effect of an Ergonomic Intervention on Musculoskeletal,Psychosocial and Visual Strain of VDT Entry Work: Organization and Methodology of the International Study

This special issue of the International Journal of Occupational Safety and Ergonomics (JOSE) reports the results from an extensive multinational and multidisciplinary collaborative investigation of the impacts on visual display terminal (VDT) work of musculoskeletal, visual, ergonomic, and psychosocial factors. For brevity, this effort has been referred to as the MEPS project (musculoskeletal—eyestrain—psychosocial—stress). This paper lays out the basic methodological structure of the study. The study was conducted in 4 countries utilizing VDT data entry workers as the primary subject population. A battery of objective and subject assessment measures, including muscle load, visual function, physical and visual strain, postural, ergonomic and psychosocial factors, were assessed at 3 different points in time. A pre-test was given prior to an ergonomic intervention. Two post-tests were given 1 month and 1 year after the ergonomic intervention.     

Do salmon farms increase the concentrations of mercury and other elements in wild fish?

Earlier assessments have suggested that salmon farms may act as a source of mercury (Hg) and other elements in local marine environments. In this study, we measured 30 elements in the livers of demersal Atlantic cod (Gadus morhua) and pelagic saithe (Pollachius virens) caught in association with salmon farms (farm associated [FA]; n = 75) or at reference locations (control; n = 80) in three regions throughout the latitudinal extent of Norway (59-70° N). Concentrations of most elements (24 of 30) were higher (20-70%) in cod compared to saithe. In particular, Hg was 6.8 times higher in cod than saithe. Nine elements were significantly different between FA saithe and control saithe, but only four (Hg, U, Cr and Mn) were highest in FA saithe, and this pattern was only detected consistently across all locations for Hg. Thirteen elements differed in concentration between FA cod and control cod, but only three elements (U, Al and Ba) were higher in FA cod than controls, and this pattern was only detected consistently across all locations for Al. After controlling for a set of potentially confounding variables, the estimated concentrations of Hg in saithe livers were ～80% higher in FA fish compared to controls. In contrast, Hg concentrations were ～40% higher in control cod compared to FA cod. Our results do not support the notion that salmon farms in general increase the concentrations of potentially harmful elements in wild fish, and the distribution of Hg and other elements in cod and saithe in Norwegian coastal waters may be more influenced by habitat use, diet, geochemical conditions and water chemistry.     

Cadmium in the shore crab <Emphasis Type="Italic">Carcinus maenas</Emphasis> along the Norwegian coast: geographical and seasonal variation and correlation to physiological parameters

Previously, high concentrations of cadmium have been found in the hepatopancreas of the edible or brown crab (Cancer pagurus) sampled from positions north of about 67° N, compared to regions further south along the Norwegian coast, with no clear understanding why. In order to study a similar organism in the same ecosystem, the present study analyzed 210 shore crabs (Carcinus maenas) from four different locations along the Norwegian coast, two in the North and two in the South. The physiological variables size, sex, molting stage, hepatosomatic index, carapace color, and gonad maturation were registered, in attempt to explain the high inter-individual variation in cadmium levels in hepatopancreas. In contrast to the brown crabs, the shore crabs showed no clear geographical differences in cadmium concentrations. This indicates physiological differences between the two crab species. No clear and consistent correlations were found between cadmium levels and physiological parameters, except for sex, where cadmium concentration in hepatopancreas was twice as high in males compared to females. The cadmium levels also varied with season, with approximately 40 and 60% lower cadmium concentration in April than August for male and female shore crabs, respectively. None of the analyzed cadmium concentrations in muscle meat from claws exceeded EUs food safety limit, and low cadmium levels in soup prepared from shore crabs clearly indicated that this dish is not problematic regarding food safety.     

Liming of River Audna,Southern Norway: a large-scale experiment of benthic invertebrate recovery

This study describes the recovery of sensitive invertebrates after liming of the anadromous part of River Audna in 1985. The river lost its salmon population during 1960-1970. The aim of the liming was to produce a water quality with pH > 6.0 and ANC > 20 microg L(-1) and to reduce the content of labile aluminum. Highly sensitive invertebrates like the mayfly Baetis rhodani were not found in the river before liming. Two years after liming, several sensitive invertebrate species showed a positive response. B. rhodani was then recorded at 2 sites in the lower part of the river. In the following 5 years several species of sensitive invertebrates recolonized the whole limed reach of the river and became numerous. Ten years after liming the snail Lymnaea peregra was recorded in the river. The dispersa of this species was also very fast and after 5 years it was found at all investigated sites in the limed main river covering a reach of 40 km. Reduced sulfur deposition in the area also resulted in water-quality improvements in th unlimed stretches of River Audna. Comparisons between limed and unlimed localities indicated that the water quality and the critical limits of sensitive species are the ma factors determining the fauna composition in River Audna independent of the reason for the change in water quality.     

Non-thermal effects of EMF upon the mammalian brain: the Lund experience

The environment in which biology exists has dramatically changed during the last decades. Life was formed during billions of years, exposed to, and shaped by the original physical forces such as gravitation, cosmic irradiation and the terrestrial magnetism. The existing organisms are created to function in harmony with these forces. However, in the late 19th century mankind introduced the use of electricity and during the very last decades, microwaves of the modern communication society spread around the world. Today one third of the world’s population is owner of the microwave-producing mobile phones. The question is: to what extent are living organisms affected by these ubiquitous radio frequency fields? Since 1988 our group has studied the effects upon the mammalian blood-brain barrier (BBB) by non-thermal radio frequency electromagnetic fields (RF-EMF). These have been revealed to cause significantly increased leakage of albumin through the BBB of exposed rats as compared to non-exposed animals—in a total series of about two thousand animals. One remarkable observation is the fact that the lowest energy levels give rise to the most pronounced albumin leakage. If mobile communication, even at extremely low energy levels, causes the users’ own albumin to leak out through the BBB, also other unwanted and toxic molecules in the blood, may leak into the brain tissue and concentrate in and damage the neurons and glial cells of the brain. In later studies we have shown that a 2-h exposure to GSM 915 MHz at non-thermal levels, gives rise to significant neuronal damage, seen 28 and 50 days after the exposure. In our continued research, the non-thermal effects (histology, memory functions) of long-term exposure for 13 months are studied as well as the effects of short term GSM 1,800 MHz upon gene expression. Most of our findings support that living organisms are affected by the non-thermal radio frequency fields. Studies from other laboratories in some cases find effects, while in other cases effects are not seen. Our conclusion is that all researchers involved in this field have the obligation to intensify this research in order to reduce, or avoid, the possible negative effects of the man made microwaves!