Species-specific effects of four preservative treatments on oocytes and ovarian material of Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and American plaice (Hippoglossoides platessoides)

The lack of information concerning the preservation of ovarian material of fish species inhibits standardization of methods for determining fecundity and measuring oocytes. The effects of four preservatives (10% phosphate-buffered formalin, modified Gilson’s solution, 70% ethanol, and freezing) on ovarian material weight and oocyte size were quantified for prespawning Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and American plaice (Hippoglossoides platessoides). Effects of preservation were similar between Atlantic cod and haddock but different between Atlantic cod and American plaice for nearly all comparisons. Although all treatments affected the weight of ovarian material, freezing caused the most change and formalin caused the least. Such signif icant species-specific effects should be quantified in the calculation of life history characteristics, such as fecundity, to minimize error. This is one of few studies dedicated to evaluating the effects of preservation on oocytes and ovarian material and is the first to evaluate multiple preservatives on species

Science, Art and Geometrical Imagination

From the geocentric, closed world model of Antiquity to the wraparound universe models of relativistic cosmology, the parallel history of space representations in science and art illustrates the fundamental role of geometric imagination in innovative findings. Through the analysis of works of various artists and scientists like Plato, Durer, Kepler, Escher, Grisey or the present author, it is shown how the process of creation in science and in the arts rests on aesthetical principles such as symmetry, regular polyhedra, laws of harmonic proportion, tessellations, group theory, etc., as well as beauty, conciseness and emotional approach of the world.Comment: 22 pages, 28 figures, invited talk at the IAU Symposium 260 "The Role of Astronomy in Society and Culture", UNESCO, 19-23 January 2009, Paris, Proceedings to be publishe

Operationalizing ensemble models for scientific advice to fisheries management

This paper explores the possibility of using the ensemble modelling paradigm to fully capture assessment uncertainty and improve the robustness of advice provision. We identify and discuss advantages and challenges of ensemble modelling approaches in the context of scientific advice. There are uncertainties associated with every phase in the stock assessment process: data collection, assessment model choice, model assumptions, interpretation of risk, up to the implementation of management advice. Additionally, the dynamics of fish populations are complex, and our incomplete understanding of those dynamics and limited observations of important mechanisms, necessitate that models are simpler than nature. The aim is for the model to capture enough of the dynamics to accurately estimate trends and abundance, and provide the basis for robust advice about sustainable harvests. The status quo approach to assessment modelling has been to identify the “best” model and generate advice from that model, mostly ignoring advice from other model configurations regardless of how closely they performed relative to the chosen model. We discuss and make suggestions about the utility of ensemble models, including revisions to the formal process of providing advice to management bodies, and recommend further research to evaluate potential gains in modelling and advice performance.publishedVersio

Time course of bone loss in patients with anorexia nervosa

Objective: To evaluate the time course of bone mineral density (BMD) in women with anorexia nervosa (AN) during two years of follow-up. Methods: We prospectively studied 51 female with AN aged 18-38 years, and forty age-matched healthy women (19-34 years). BMD was measured in lumbar spine (LS), femoral neck (FN) and total hip (TH) by DXA. Results: At baseline, weight, body mass index, and lumbar and hip BMD were significantly (p<0.001) lower in AN patients than in controls. Patients who gain weight showed a significant increase in BMD at FN (+1.6%; p<0.05), and TH (+4.4%; p<0.05) and lower non significant changes in LS (+1.3%). Weight at entry, and percent change of weight were significant determinants (p<0.05) of the variability in percent change of BMD at FN and TH, whereas weight at entry was the main determinant of bone modifications at lumbar spine. Conclusions: Our data emphasize the influence of weight gain in recovery of bone mass in AN patients, especially at the hip

of nerve cells: A developmental study of two molecular components

1. 1. The development of the lysosomal hydrolase was examined in bulk-isolated nerve cell bodies of rat cerebral cortex. Several properties of the enzyme and of two of its molecular components were compared, among them their ease of solubilization, their relative abundance, their heat lability and their behavior on density gradients of sucrose.2. 2. Repeated freezing-thawing of neuronal particulates in 0.20 M sucrose-0.1 M KCl followed by centrifugation at moderate rather than high speeds resulted in the solubilization of upward of 50% of the glucosaminidase, irrespective of neuronal age.3. 3. Although the solubilization of was dependent on the concentration (mg of protein/ml) of the suspension subjected to freezing-thawing, it was always more effective with the enzyme from the 8- and 18-day-old than with that from the 3- and 5-day-old neurons.4. 4. Centrifugation of the solubilized neuronal on linear density gradients of sucrose resulted, at all ages, in the complete resolution of two activity components a heavy and a light one, H and L respectively. As routinely isolated, the ratio of component L to component H in the neurons of the cerebral cortex was always &gt; 1.0 while, in the cerebellar neurons, values 5. 5. The qualitative and quantitative gradient profiles of activity were highly sensitive to pH. Thus, lowering of the pH of frozen thawed supernatants to 5.4 and below prior to density gradient centrifugation resulted in the virtual disappearance of component H, while adjustment of the pH to 5.6 resulted in L/H ratios 6. 6. About 50% of the activity of component L was lost, irrespective of age, by heating for 20 min at 50 [deg]C and at a pH of 4.1. The heat sensitivity of component H was no greater, except at 5 days, when about 90% of its activity was lost under the same conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33848/1/0000106.pd

Both “illness and temptation of the enemy”: melancholy, the medieval patient and the writings of King Duarte of Portugal (r. 1433–38)

Recent historians have rehabilitated King Duarte of Portugal, previously maligned and neglected, as an astute ruler and philosopher. There is still a tendency, however, to view Duarte as a depressive or a hypochondriac, due to his own description of his melancholy in his advice book, the Loyal Counselor. This paper reassesses Duarte's writings, drawing on key approaches in the history of medicine, such as narrative medicine and the history of the patient. It is important to take Duarte's views on his condition seriously, placing them in the medical and theological contexts of his time and avoiding modern retrospective diagnosis. Duarte's writings can be used to explore the impact of plague, doubt and death on the life of a well-educated and conscientious late-medieval ruler