Economic repercussions of fisheries-induced evolution

Fish stocks experiencing high fishing mortality show a tendency to mature earlier and at a smaller size, which may have a genetic component and therefore long-lasting economic and biological effects. To date, the economic effects of such ecoevolutionary dynamics have not been empirically investigated. Using 70 y of data, we develop a bioeconomic model for Northeast Arctic cod to compare the economic yield in a model in which life-history traits can vary only through phenotypic plasticity with a model in which, in addition, genetic changes can occur. We find that evolutionary changes toward faster growth and earlier maturation occur consistently even if a stock is optimally managed. However, if a stock is managed optimally, the evolutionary changes actually increase economic yield because faster growth and earlier maturation raise the stock’s productivity. The optimal fishing mortality is almost identical for the evolutionary and nonevolutionary model and substantially lower than what it has been historically. Therefore, the costs of ignoring evolution under optimal management regimes are negligible. However, if fishing mortality is as high as it has been historically, evolutionary changes may result in economic losses, but only if the fishery is selecting for medium-sized individuals. Because evolution facilitates growth, the fish are younger and still immature when they are susceptible to getting caught, which outweighs the increase in productivity due to fish spawning at an earlier age.     

Dietary Mustard Seeds (Sinapis alba Linn) Suppress 1,2-Dimethylhydrazine-Induced Immuno-Imbalance and Colonic Carcinogenesis in Rats

In a Wistar rat model, prolonged supplementation of mustard seed (MS) to the diet significantly ameliorates the induction of colorectal carcinomas by 1,2-dimethylhydrazine (DMH). The expression of the splenocyte major histocompatibility complex class I (MHCI) was found significantly enhanced, whereas that of the major histocompatibility complex class II (MHCII) was significantly decreased. Compared to that of control animals, the proportion of spleenic B- and dendritic cells (DC) was amplified in the MS group. The expressions of MHCI, as well as that of MHCII, were increased in DC cells; whereas in B cells, MHCI expression was augmented but that of MHCII moderately decreased. The percentages of CD8+CD28+ and CD4+CD28+ cells were increased in the MS group, while the CD4+CD25+Foxp3+ subset was depressed. Plasma analysis showed that DMH-exposure induced amplified amounts of interleukin (IL)-4, IL-5, IL-10, and transforming growth factor-beta, whereas MS feeding counteracted this effect but enhanced IL-2, IL12p70, IL21, TNF-alpha, and interferon-gamma. In the SW480 colon adenocarcinoma cell-line, the cytotoxicity of spleenic T-cells from MS-fed animals was significantly increased. In the DMH-exposed rats, the expression of perforin in the spleenic T-cells was dramatically decreased, whereas MS abolished this depression. In summary, dietary MS suppresses DMH-induced immuno-imbalance as well as colon carcinogenesis in rats.     

Psychosocial aspects of dental and general fears in dental phobic patients

Phobic reactions can often be a significant health problem for fearful dental patients. This is true in particular for individuals with long-time avoidance and elevated general psychological distress. The aim of this study was to investigate the expression of dental fear among 67 dental phobic individuals with a low versus high degree of general fear. Reported etiologic background factors, avoidance time, general psychological distress and psychosocial manifestations and consequences of dental phobia were studied. No significant difference in dental anxiety level between individuals with low versus high general fear was found, and both groups reported high frequencies of negative dental experiences. The low-fear group reported a longer (though not statistically significant) average avoidance time than the high-fear group. However, patients with a high level of general fear showed a significantly higher degree of psychological distress, and also reported stronger negative social consequences from their dental anxiety. These results indicate that the character of dental fear might be different between different groups of fearful patients, which makes the condition psychologically handicapping. Such aspects should be assessed in the diagnostic analysis of patients with severe dental anxiety. In particular, assessments of signs of general psychological distress are warranted.     

Cutting efficiency of diamond burs operated with electric high‐speed dental handpiece on zirconia

Zirconia‐based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high‐speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass–ceramic (LD) and leucite glass–ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5‐ and 7‐fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations.     

Lymphocyte Subpopulations,Oxidative Burst and Apoptosis in Peripheral Blood Cells of Patients with Multiple Sclerosis–Effect of Interferon-β

At present, the most efficient therapeutical treatment of multiple sclerosis (MS) is achieved by IFN-β. However, its in vivo effects remain incompletely understood. If applied parenterally, the hydrophobic IFN-β acts primarily on blood cells with probable selectivity for functionally different lymphocyte subpopulations, monocytes and granulocytes. We have investigated the expression of the activation marker interleukin-2 receptor-α (CD25) on CD3⁺ T cells, CD19⁺ B cells, foetal-type γδ⁺CD3⁺ T cells and foetal-type CD5⁺CD19⁺ B cells of the peripheral blood. In addition, the oxidative burst activity and apoptosis have been determined in mononuclear and polymorphonuclear blood cells, respectively. The study accompanied a phase III trial with IFN-β1b (BETAFERON^®, Schering). Two groups of MS patients with relapsing-remitting course of the disease have been investigated at 8 time points (days 0, 5, 15, 31, 60, 90, 180 and 270 after starting therapy): (1) verum group (n=8) with application of 8 Mill. units IFN-β1b every other day, and (2) placebo group (n=4) with application of placebo for 3 months and therapy as in (1) from day 90 onward. The main results were: (1) Activated T cells decreased until day 180 in the verum group and return thereafter to pre-treatment values, whereas in the placebo group the values remained relatively stable over the whole observation period. (2) Activated B cells increased between days 90 and 270 in both groups, i.e. after verum application in both groups. (3) Foetal-type B cells were more activated than total B and T cells with increase over time in both groups. (4) Foetal-type T cells exerted relatively stable intra-individual levels with generally low CD25 expression, but punctual CD25 peaks in both groups. (5) The spontaneous oxidative burst was higher in lymphocytes, more variable in monocytes and faster increasing in granulocytes in the verum group than in the placebo group. (6) Apoptosis of mononuclear cells and granulocytes showed similar variations in the verum and placebo groups with the exception of a selective increase over time of the proportion of granulocytes undergoing induced apoptosis in the verum group. It is concluded that IFN-β has the following main effects on the immune system of MS patients: (1) the T cell immunity is systemically and reversibly suppressed, (2) the foetal-type lymphocytes, which are responsible for the first line of defence of infections, are stimulated in the long range, (3) the oxidative burst activity is increased in lymphocytes and granulocytes and instable in monocytes, and (4) the inducibility of apoptosis in granulocytes is increased. Re-examination of the altered blood cell parameters after long-term IFN-β therapy is warranted.