Seglen P.O.,University of Oslo |
Brinchmann M.F.,Bodo University College
Autophagy | Year: 2010
To facilitate the purification of rat liver autophagosomes, isolated rat hepatocytes are first incubated for 2 h at 37° C with vinblastine, which induces autophagosome accumulation by blocking the fusion of these organelles with endosomes and lysosomes. The hepatocytes are then electrodisrupted and homogenized, and the various cellular organelles sequentially removed by subcellular fractionation. A brief incubation of the homogenate with the cathepsin C substrate, glycyl-phenylalanine-naphthylamide (GPN), causes rapid osmotic disruption of the lysosomes due to intralysosomal accumulation of GPN cleavage products. Nuclei are removed by differential centrifugation, and the postnuclear supernatant subsequently fractionated on a two-step Nycodenz density gradient. Autophagosomes are recovered in an intermediate density fraction, free from cytosol and mitochondria. The autophagosomes are finally separated from the membranes and vesicles of the endoplasmic reticulum, Golgi, endosomes, etc., by sieving through a density gradient of colloidal silica particles (Percoll). The final preparation contains about 95% autophagosomes and 5% amphisomes according to morphological and biochemical criteria. © 2010 Landes Bioscience.
Enoksen E.,Norwegian School of Sport Sciences |
Shalfawi S.A.I.,Bodo University College |
Journal of Strength and Conditioning Research | Year: 2011
The purpose of this study was to examine the effect of 2 different intervention training regimes on V̇o2max, V̇o2max velocity (vV̇o2max), running economy (RE), lactic threshold velocity (vLT), and running performance on a group of well-trained male middle-distance runners in the precompetition period. Twenty-six well-trained male middle-distance runners took part in the study. All participants were tested on V̇o2max, vV̇o2max, RE, lactate threshold (LT), vLT, and a performance test. The participants were matched according to their pretest results, then randomly assigned into 1 of 2 groups, a high-volume (70 km) low-intensity training group (HVLI-group); or a high-intensity low-volume (50 km) training group (HILV-group). No significant differences were found between the 2 groups on all measures both before and after the intervention period. Furthermore, the HILV-group had a marked increase in vV̇o2max and vLT after the training period when compared with pretest. Both groups had a marked improvement in RE. The performance test showed that the HILV-group made 301 ± 886 m (1.0 ± 2.8 minutes) and the HVLI-group 218 ± 546 m (0.9 ± 1.8 minutes) in progress. The production of lactic acid was notably higher in the HILV-group (0.9 mmol) when compared with the pretest. The findings show that male middle-distance runners tested in this study improved in vV̇o2max and vLT more when they train around LT, than training with low intensity for a short period of 10 weeks. © 2011 National Strength and Conditioning Association.
Erikstad K.E.,Norwegian Institute for Nature Research |
Moum T.,Bodo University College |
Bustnes J.O.,Norwegian Institute for Nature Research |
Reiertsen T.K.,University of Tromsø
Functional Ecology | Year: 2011
1.Long range transportation via ocean currents and air of various organochlorines (OCs) has resulted in their intrusion in the high Arctic marine food web. At the Spitsbergen archipelago, including Bear Island (Norway), bioaccumulation in top predators like glaucous gulls (Larus hyperboreus) is high, severely affecting their breeding performance and survival. 2.In the present study, we examined the sex ratio of glaucous gull offspring at hatching in relation to the OC blood levels of female parents. Glaucous gulls have male-biased size dimorphism and females under stress with high levels of OCs are expected to skew the sex ratio towards the less costly female offspring. 3.Our data strongly suggest that among females with low levels of OCs, mothers in good body condition had a hatching sex ratio skewed towards males while those in poor body condition had a skew towards female offspring. However, contrary to expectations, females with high levels of OCs had a strong skew in sex ratio toward male offspring and this was most apparent among females in poor body condition. 4.Hatching body masses of male chicks (controlled for egg size) were negatively related to OC blood level of female parents. There was no such relationship for female offspring. 5.We discuss the skew in hatching sex ratio experienced by OC contaminated glaucous gulls in light of three hypotheses. One is that OC pollutants may mimic hormones and influence the sex determining processes suggested to be under control of steroids. Another is that female transfer of OCs to eggs may increase female embryo mortality. A third hypothesis is that elevated levels of OCs could trigger increased parental investment (terminal investment) which may represent an abortive strategy for OC contaminated gulls, further aggravating the negative impact of OCs on gull population parameters. © 2010 The Authors. Functional Ecology © 2010 British Ecological Society.
Gaardsted F.,University of Tromsø |
Tande K.S.,Bodo University College |
Basedow S.L.,University of Tromsø
Fisheries Oceanography | Year: 2010
The main purpose of this study was to assess the usefulness of the laser optical plankton counter (LOPC) as a Calanus finmarchicus monitoring tool in the NE Norwegian Sea in winter. To test this, a multinet and an LOPC were used simultaneously to sample overwintering copepods in the Lofoten basin in January 2007. Additional data from an LOPC laboratory experiment were also analyzed to help the interpretation of the field data. Both the laboratory data and the field data indicated that the presence of particles other than zooplankton generally contaminated the zooplankton signal in the LOPC data. However, reliable abundance estimates could be made from the LOPC data by choosing an appropriate size range in the LOPC size distribution. This size range was determined by comparing LOPC abundance estimates from systematically varying size ranges to multinet zooplankton abundance data. The average difference was smallest for a size range of about 900-1500 μm. As C. finmarchicus, stages IV and V, was by far the most abundant species in the NE Norwegian Sea, abundance estimates from the LOPC in this size range were in practice estimates of C. finmarchicus abundance, making the LOPC suitable as a tool for providing high resolution winter data in the NE Norwegian Sea. © 2010 Blackwell Publishing Ltd.
Sarropoulou E.,Hellenic Center for Marine Research |
Fernandes J.M.O.,Bodo University College
Comparative Biochemistry and Physiology - Part D: Genomics and Proteomics | Year: 2011
Comparative genomics is a powerful tool to transfer knowledge coming from model fish species to non-model fish species of economic or/and evolutionary interest. Such transfer is of importance as functional studies either are difficult to perform with most non-model species. The first comparative map constructed using the human and the chimpanzee genome allowed the identification of putative orthologues. Although comparative mapping in teleosts is still in its infancy, five model teleost genomes from different orders have been fully sequenced to date and the sequencing of several commercially important species are also underway or near completion. The accessibility of these whole genome sequences and rapid developments in genomics of fish species are paving the way towards new and valuable research in comparative genetics and genomics. With the accumulation of information in model species, the genetic and genomic characterization of non-model, but economically, physiologically or evolutionary important species is now feasible. Furthermore, comparison of low coverage gene maps of non-model fish species against fully sequenced fish species will enhance the efficiency of candidate gene identification projected for quantitative trait loci (QTL) scans for traits of special interest. © 2010 Elsevier Inc. All rights reserved.
Bjornevik M.,Bodo University College |
Solbakken V.,Bodo University College
Aquaculture Research | Year: 2010
The aim of this study was to investigate the effect of prehandling stress on the flesh quality of Atlantic cod (Gadus morhua). In order to stress the animal, water was reduced in the tank before a total of 30 fish were caught five at a time using a dipnet and held for 3 min, causing stress by hypoxia. This fish was compared with a control group (n=30) of fish exposed to anaesthetics directly in the tank. All fish were killed by a percussive blow to the head and exsanguinated and stored on ice before flesh quality was measured. Immediately after death and after ice storage for 3 and 8 days, 10 fish per group were measured for muscle pH, texture, fillet gaping, colour, drip loss and cathepsin D. Handling stress resulted in an initial increased fillet lightness, drip loss and decreased fillet shear force, although these differences did level off during ice storage. Stress caused by handling resulted in earlier onset of rigour mortis as compared with the control group, which reached maximum rigour tensions within 26 and 36 h postmortem respectively. We conclude that handling before harvest results in reduced time before entering rigour. After 8 days of ice storage, no effect of handling stress was seen on the muscle pH, flesh colour, fillet shear force, gaping score, drip loss or cathepsin D activity. © 2010 The Authors. Aquaculture Research © 2010 Blackwell Publishing Ltd.
Hagen T.,Bodo University College
Food Chemistry | Year: 2011
In the present study, fillet colour, pH and the activities of cathepsin B, B+L, D, H, collagenase and calpain were measured in 50 Atlantic halibut (Hippoglossus hippoglossus) farmed and harvested at Mørkvedbukta research station (Bodø University College) in May, 2009. May is a period of the year when a portion of the fish can temporarily lose its translucent colour, becoming milky instead, a phenomena referred to as chalky halibut. The aim of the present study was to discover whether enzymes, known to be involved in flesh quality degradation, are also involved in the post-mortem discoloration of halibut flesh. Colour assessment was performed using a Minolta instrument (L value) and a linear regression showed that pH had the most pronounced effect on chalkiness (r2=0.81, p<0.001). Of the investigated enzymes, cathepsins B and D explained 35 and 13% of the total variation, respectively (p<0.01). In addition, an unexpected inverse relationship between chalkiness and calpain was found (r2=0.48, p<0.001). The present results suggest that the activity of cathepsins contributes to the development of chalkiness in Atlantic halibut. © 2010 Elsevier Ltd.
Hagen N.T.,Bodo University College
Scientometrics | Year: 2010
A collection of coauthored papers is the new norm for doctoral dissertations in the natural and biomedical sciences, yet there is no consensus on how to partition authorship credit between PhD candidates and their coauthors. Guidelines for PhD programs vary but tend to specify only a suggested range for the number of papers to be submitted for evaluation, sometimes supplemented with a requirement for the PhD candidate to be the principal author on the majority of submitted papers. Here I use harmonic counting to quantify the actual amount of authorship credit attributable to individual PhD graduates from two Scandinavian universities in 2008. Harmonic counting corrects for the inherent inflationary and equalizing biases of routine counting methods, thereby allowing the bibliometrically identifiable amount of authorship credit in approved dissertations to be analyzed with unprecedented accuracy. Unbiased partitioning of authorship credit between graduates and their coauthors provides a post hoc bibliometric measure of current PhD requirements, and sets a de facto baseline for the requisite scientific productivity of these contemporary PhD's at a median value of approximately 1.6 undivided papers per dissertation. Comparison with previous census data suggests that the baseline has shifted over the past two decades as a result of a decrease in the number of submitted papers per candidate and an increase in the number of coauthors per paper. A simple solution to this shifting baseline syndrome would be to benchmark the amount of unbiased authorship credit deemed necessary for successful completion of a specific PhD program, and then monitor for departures from this level over time. Harmonic partitioning of authorship credit also facilitates cross-disciplinary and inter-institutional analysis of the scientific output from different PhD programs. Juxtaposing bibliometric benchmarks with current baselines may thus assist the development of harmonized guidelines and transparent transnational quality assurance procedures for doctoral programs by providing a robust and meaningful standard for further exploration of the causes of intra- and inter-institutional variation in the amount of unbiased authorship credit per dissertation. © 2010 The Author(s).
Hagen N.T.,Bodo University College
Scientometrics | Year: 2010
Bibliometric counting methods need to be validated against perceived notions of authorship credit allocation, and standardized by rejecting methods with poor fit or questionable ethical implications. Harmonic counting meets these concerns by exhibiting a robust fit to previously published empirical data from medicine, psychology and chemistry, and by complying with three basic ethical criteria for the equitable sharing of authorship credit. Harmonic counting can also incorporate additional byline information about equal contribution, or the elevated status of a corresponding last author. By contrast, several previously proposed counting schemes from the bibliometric literature including arithmetic, geometric and fractional counting, do not fit the empirical data as well and do not consistently meet the ethical criteria. In conclusion, harmonic counting would seem to provide unrivalled accuracy, fairness and flexibility to the long overdue task of standardizing bibliometric allocation of publication and citation credit. © 2009 The Author(s).
Maseide P.,Bodo University College
Sociology of Health and Illness | Year: 2011
This article focuses on respiratory physiological examinations conducted in the respiratory physiological lab of a Norwegian hospital ward. The examinations were aimed at producing exact and objective measures of patients' respiratory functions or capacities. The quality of the examinations depended on correct use of technology and adequate body work by professionals and patients. The concept of 'body work' has several meanings. The professionals' body work was not direct hands-on work. Their contact with the patient was communicative and informed or guided by technical devices. Although the patient's objective body constituted the focus of examination, it necessitated an active and compliant patient. The concrete outcome of the examination was a textual artefact that in the examination situation counted as the accurate and objective representation of the patient's respiratory physiological status. These examinations represented a mutually constitutive process between various agents, bodies and bodily modes required for and aimed at by the examination; different articulations of body work were essential for these processes. The objective of the article is to examine the kinds of body work that are conducted, paying particular attention to the conceptions of bodies that are practically generated during these examinations. © 2011 The Author. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.