A gyermek 13 (1919) 01

A gyermek A Magyar Gyermektanulmányi Társaság közlönye 13. évfolyam Budapest, 1920. A folyóirat 1908-ig a Gyermekvédelmi lap mellékleteként, 1909-től mint önálló lap jelent meg

A gyermek 9 (1915) 07-08

A gyermek A Magyar Gyermektanulmányi Társaság közlönye 9. évfolyam, 07-08. szám Budapest, 1915. A folyóirat 1908-ig a Gyermekvédelmi lap mellékleteként, 1909-től mint önálló lap jelent meg

Presence, variation, and potential ecological impact of microplastics in the largest shallow lake of Central Europe

The presence of microplastics (MPs) in the global ecosystem has generated a rapidly growing concern worldwide. Although their presence in the marine environment has been well-studied, much less data are available on their abundance in freshwaters. MPs alone and in combination with different chemicals has been shown to cause acute and chronic effects on algae and aquatic invertebrate and vertebrate species at different biological levels. However, the combined ecotoxicological effects of MPs with different chemicals on aquatic organisms are still understudied in many species and the reported data are often controversial. In the present study, we investigated, for the first time, the presence of MPs in Lake Balaton, which is the largest shallow lake of Central Europe and an important summer holiday destination. Moreover, we exposed neonates of the well-established ecotoxicological model organism Daphnia magna to different MPs (polystyrene [3 μm] or polyethylene [≤ 100 μm]) alone and in combination with three progestogen compounds (progesterone, drospirenone, levonorgestrel) at an environmentally relevant concentration (10 ng L−1) for 21 days. The presence of 7 polymer types of MPs in the size range of 50–100 μm was detected in Lake Balaton. Similarly to the global trends, polypropylene and polyethylene MPs were the most common types of polymer. The calculated polymer-independent average particle number was 5.5 particles m−3 (size range: 50 μm – 100 μm) which represents the values detected in other European lakes. Our ecotoxicological experiments confirmed that MPs and progestogens can affect D. magna at the behavioral (body size and reproduction) and biochemical (detoxification-related enzyme activity) levels. The joint effects were negligible. The presence of MPs may lead to reduced fitness in the aquatic biota in freshwaters such as Lake Balaton, however, the potential threat of MPs as vectors for progestogens may be limited

Examination of Physical Activity Patterns of Children, Reliability and Structural Validity Testing of the Hungarian Version of the PAQ-C Questionnaire

Introduction: Several studies report on the importance of physical activity (PA) in childhood, which influences attitudes towards health in adulthood. For monitoring PA, trustworthy measurement tools are needed. The study aimed to adapt the Physical Activity Questionnaire for Children (PAQ-C) to the Hungarian language and assess its validity, reliability, and factor structure. Methods: A total of 620 children (the average age was 10.62 (SD 2.36)) participated in the cross-sectional study. To assess physical activity, the PAQ-C questionnaire was used. The collected data were analysed using IBM SPSS version 28.0 and IBM SPSS AMOS 29.0 software. Results: The internal consistency was acceptable (alpha = 0.729) and the test-retest reliability showed acceptable agreement (ICC = 0.772). The confirmatory factor favoured a one-factor structure of the questionnaire. The average PAQ-C score for girls was 2.87 (SD 1.07), and for boys it was 3.00 (SD 1.05), which showed a significant difference (p = 0.005). Discussion: Based on our findings, our study tested the validity and reliability of the one-factor PAQ-C questionnaire, a valid and reliable measurement tool to test the physical activity patterns of primary school children in a Hungarian sample. Further research is needed to develop physical activity monitoring of Hungarian children

Soil related developments of the Biome-BGCMuSo v6.2 terrestrial ecosystem model by integrating crop model components

Abstract. Terrestrial biogeochemical models are essential tools to quantify climate-carbon cycle feedback and plant-soil relations from local to global scale. In this study, theoretical basis is provided for the latest version of Biome-BGCMuSo biogeochemical model (version 6.2). Biome-BGCMuSo is a branch of the original Biome-BGC model with a large number of developments and structural changes. Earlier model versions performed poorly in terms of soil water content (SWC) dynamics in different environments. Moreover, lack of detailed nitrogen cycle representation was a major limitation of the model. Since problems associated with these internal drivers might influence the final results and parameter estimation, additional structural improvements were necessary. During the developments we took advantage of experiences from the crop modeller community where internal process representation has a long history. In this paper the improved soil hydrology and soil carbon/nitrogen cycle calculation methods are described in detail. Capabilities of the Biome-BGCMuSo v6.2 model are demonstrated via case studies focusing on soil hydrology and soil organic carbon content estimation. Soil hydrology related results are compared to observation data from an experimental lysimeter station. The results indicate improved performance for Biome-BGCMuSo v6.2 compared to v4.0 (explained variance increased from 0.121 to 0.8 for SWC, and from 0.084 to 0.46 for soil evaporation; bias changed from −0.047 to 0.007 m3 m−3 for SWC, and from −0.68 mm day−1 to −0.2 mm day−1 for soil evaporation). Sensitivity analysis and optimization of the decomposition scheme is presented to support practical application of the model. The improved version of Biome-BGCMuSo has the ability to provide more realistic soil hydrology representation and nitrification/denitrification process estimation which represents a major milestone. </jats:p

Soil-related developments of the Biome-BGCMuSo v6.2 terrestrial ecosystem model

Abstract. Terrestrial biogeochemical models are essential tools to quantify climate–carbon cycle feedback and plant–soil relations from local to global scale. In this study, a theoretical basis is provided for the latest version of the Biome-BGCMuSo biogeochemical model (version 6.2). Biome-BGCMuSo is a branch of the original Biome-BGC model with a large number of developments and structural changes. Earlier model versions performed poorly in terms of soil water content (SWC) dynamics in different environments. Moreover, lack of detailed nitrogen cycle representation was a major limitation of the model. Since problems associated with these internal drivers might influence the final results and parameter estimation, additional structural improvements were necessary. In this paper the improved soil hydrology as well as the soil carbon and nitrogen cycle calculation methods are described in detail. Capabilities of the Biome-BGCMuSo v6.2 model are demonstrated via case studies focusing on soil hydrology, soil nitrogen cycle, and soil organic carbon content estimation. Soil-hydrology-related results are compared to observation data from an experimental lysimeter station. The results indicate improved performance for Biome-BGCMuSo v6.2 compared to v4.0 (explained variance increased from 0.121 to 0.8 for SWC and from 0.084 to 0.46 for soil evaporation; bias changed from −0.047 to −0.007 m3 m−3 for SWC and from −0.68 to −0.2 mm d−1 for soil evaporation). Simulations related to nitrogen balance and soil CO2 efflux were evaluated based on observations made in a long-term field experiment under crop rotation. The results indicated that the model is able to provide realistic nitrate content estimation for the topsoil. Soil nitrous oxide (N2O) efflux and soil respiration simulations were also realistic, with overall correspondence with the observations (for the N2O efflux simulation bias was between −0.13 and −0.1 mgNm-2d-1, and normalized root mean squared error (NRMSE) was 32.4 %–37.6 %; for CO2 efflux simulations bias was 0.04–0.17 gCm-2d-1, while NRMSE was 34.1 %–40.1 %). Sensitivity analysis and optimization of the decomposition scheme are presented to support practical application of the model. The improved version of Biome-BGCMuSo has the ability to provide more realistic soil hydrology representation as well as nitrification and denitrification process estimation, which represents a major milestone. </jats:p