Gender and injury in Finnish comprehensive schools

The aim of this study is to analyze the gender differences in injuries at Finnish comprehensive schools. Nine schools reported a total of 1135 injuries to the injury register over two school years. Boys (56%) were injured more often than girls, their injuries happened more often during breaks at school yard, whereas girls hurt themselves during sport lectures in the gymnastic halls. The proportion of boys' injuries also increased with age. More often, boys' injuries were caused by intentional actions by other pupils. Girls injured their lower extremities more often, whereas boys injured their faces and head. Boys also suffered concussion more often than girls, and were also referred for further care to health care centres or hospitals more often than girls. The higher injury frequency among boys at school corresponds to the higher injury rate of males in general, which is true for work, traffic, and leisure-time injuries. Increased adult supervisor control especially during breaks can prevent most of school injuries.     

Climate induced thermocline change has an effect on the methyl mercury cycle in small boreal lakes

We conducted a whole-lake experiment by manipulating the stratification pattern (thermocline depth) of a small polyhumic, boreal lake (Halsjärvi) in southern Finland and studying the impacts on lake mercury chemistry. The experimental lake was compared to a nearby reference site (Valkea-Kotinen Lake). During the first phase of the experiment the thermocline of Halsjärvi was lowered in order to simulate the estimated increase in wind speed and in total lake heat content (high-change climate scenario). The rate of methyl mercury (MeHg) production during summer stagnation (May-August) was calculated from water profiles before the treatment (2004), during treatment (2005, 2006) and after treatment (2007). We also calculated fluxes of MeHg from the epilimnion and from the hypolimnion to the sediments using sediment traps. Experimental mixing with a submerged propeller caused a 1.5-2 m deepening of the thermocline and oxycline. Methyl mercury production occurred mostly in the oxygen free layers in both lakes. In the experimental lake there was no net increase in MeHg during the experiment and following year; whereas the reference lake showed net production for all years. We conclude that the new exposed epilimnetic sediments caused by a lowering of the thermocline were a major sink for MeHg in the epilimnion. The results demonstrate that in-lake MeHg production can be manipulated in small lakes with anoxic hypolimnia during summer. The climate change induced changes in small boreal lakes most probably affect methyl mercury production and depend on the lake characteristics and stratification pattern. The results support the hypothesis that possible oxygen related changes caused by climate change are more important than possible temperature changes in small polyhumic lakes with regularly occurring oxygen deficiency in the hypolimnion.     

The use of malolactic Oenococcus oeni (ATCC 39401) for deacidification of media containing glucose, malic acid and citric acid

 Malolactic fermentation is widely used to reduce the acidity of grape juices in wine production. However, application of the same technology to the production of wine from berries of the northern regions is not straightforward. Unlike grapes, these berries are rich in citric and malic acid while the sugar content is low. An ideal deacidification process for the northern berries would be the microbial degradation of these acids with minimal loss of sugars. Therefore, the co-metabolism of citric acid and glucose was studied under different conditions of malic acid degradation by Oenococcus oeni. At low pH values (pH <4.5) degradation of malic acid always proceeded first to completion with practically no consumption of glucose or citric acid. After the exhaustion of malic acid the degradation of both citric acid and glucose were initiated simultaneously. Following the exhaustion of malic acid and citric acid the remaining glucose remained nonfermentable. Thus, it is concluded that, by maintaining the culture in a resting state by the control of pH, selective degradation of acids can be achieved without subsequent loss of glucose. Received: 20 January 2000     

Guest Editorial: MLSP 2020 Special Issue

Journal of Signal Processing Systems -     

Anisotropic modelling and numerical simulation of brittle damage in concrete

A framework for damage mechanics of brittle solids is presented and exploited in the design and numerical implementation of an anisotropic model for the tensile failure of concrete. The key feature exploited in the analysis is the hypothesis of maximum dissipation, which specifies a unique damage rule for the elastic moduli of the solid once a failure surface is specified. A complete algorithmic treatment of the resulting model is given which renders a useful tool for large-scale inelastic finite element calculations. A rather simple three-surface failure model for concrete, containing essentially no adjustable parameters, is shown to produce results in remarkably good agreement with sample experimental data.     

Exploratory assessment of the dynamic behavior of multimachinesystem stabilized by a SMES unit

A new linear model of superconducting magnetic energy storage (SMES) system is designed for dynamic stability analysis in multimachine power system. An equivalent current source for the SMES unit is assumed. The linear model includes voltage, active power and energy regulators. On a sample network, eigenanalysis using the QR algorithm shows that the proposed model increases the damping of slow oscillation modes. Step-response simulations illustrate the positive impact of the SMES regulator as a power system stabilizer. Performing the component connection method (CCM), the approach is attractive in case one or more additional SMES units should be considered     

Congenital giant hydronephrosis in adults

Giant hydronephrosis is the term designating the presence of more than 1,000 ml. of fluid in the collecting system. Of 4 cases of congenital hydronephrosis found over a three-year period at the Ochsner Medical Institutions, 2 were associated with unsuspected carcinomas. Hydronephrosis may first be detected as a mass palpable in the abdomen and displacing the intestines on gastrointestinal films. Excretory urography, retrograde pyelography, and angiography confirm the diagnosis. The treatment of choice is nephrectomy.     

A unified approach to finite deformation elastoplastic analysis based on the use of hyperelastic constitutive equations

By assuming from the outset hyperelastic constitutive behavior, an alternative approach to finite deformation plasticity and viscoplasticity is proposed whereby the need for integration of spatial rate constitutive equations is entirely bypassed. To enhance the applicability of the method, reference is made to a general formulation of plasticity and viscoplasticity which embodies both the multiplicative and additive theories. A new return mapping algorithm capable of accommodating general yield conditions, arbitrary flow and hardening rules and non-constant tangent elasticities is proposed. Finally, a numerical example is presented which illustrates the excellent performance of the method for very large time steps.