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Production and soil restoration effect of pioneer tree species in a region of allochthonous Norway spruce dieback
Get PDFThe paper analyses the growth, structure, production and soil chemistry of different tree species stands 20 years after allochthonous spruce dieback. The experiment was carried out at lower altitudes (300 m a.s.l.) at rich sites of the Central Europe region. Norway spruce (Picea abies Linnaeus) and beech (Fagus sylvatica Linnaeus) stands established by artificial regeneration were compared with silver birch (Betula pendula Roth), aspen (Populus tremula Linnaeus) and birch-aspen stands, which were regenerated naturally. Spruce stands showed a decrease of site index (site index 3), compared with the previous generation (site index 2). This leads to an expected lower production at the age of 100 years, compared to mature beech stands, which showed a site index of 1. The highest production (tree overbark volume) was found out in the aspen stand - 294 m3.ha-1. The production (tree overbark volume) of other monoculture stands was comparable and reached 201-222 m3.ha-1. Most of the soil chemical characteristics under the compared stands (Ca and Mg content, Al content and active and potential soil reaction) were significantly better under aspen and decreased in the following trend: birch - beech - spruce.O
Using HMM Approach for Assessing Quality of Value at Risk Estimation: Evidence from PSE Listed Company
Get PDFThe article points out the possibilities of using Hidden Markov model (abbrev. HMM) for estimation of Value at Risk metrics (abbrev. VaR) in sample. For the illustration we use data of the company listed on Prague Stock Exchange in range from January 2011 to June 2016. HMM approach allows us to classify time series into different states based on their development characteristic. Due to a deeper shortage of existing domestic results or comparison studies with advanced volatility governed VaR forecasts we tested HMM with univariate ARMA-GARCH model based VaR estimates. The common testing via Kupiec and Christoffersen procedures offer generalization that HMM model performs better that volatility based VaR estimation technique in terms of accuracy, even with the simpler HMM with normal-mixture distribution against previously used GARCH with many types of non-normal innovations.O
Germination of Dracaena cinnabari Balf. f. Seeds under Controlled Temperature Conditions
Get PDFResearch highlights: This study is focused on the germination of Dracaena cinnabari seeds in order to discover the possibility of natural and artificial regeneration of this species. Background and Objectives: This study aimed to determine the optimal temperature for D. cinnabari seed germination, e.g., the temperature at which the germination percentage and germination rate (vitality) are the highest. The objectives of this study are to: (1) determine the optimal temperature for the germination of D. cinnabari seeds, (2) compare the suitability of di_erent seed collection methods, and (3) compare the germination parameters of seeds that were collected from di_erent localities. The results of this study will contribute to obtaining the highest number of seedlings from limited seed material for reforestation of the most endangered localities of D. cinnabari species. Materials and methods: Four seed sections were employed. These sections were directly collected from either the fruits of a cut panicle or the ground and were obtained from different localities that differ in altitude. The seeds were tested in a greenhouse while using Petri dishes at three different temperatures-22, 26, and 30 oC-with four replicates of 25 seeds of each section. ANOVA and the t-test were employed for data analysis. Results: The highest germination percentages (GPs) were achieved at 26 oC and 30 oC, which were 84.6% and 82.5%, respectively. The ANOVA and t-test results showed that the germination index (GI) of the species was relatively higher at a temperature of 30 oC relative to that at other temperatures in the study. Although seeds that were collected from the tree achieved a higher GP, the t-test result showed no significant differences in the GI of D. cinnabari seeds that were collected from the ground and from the tree (p > 0.05). Overall, the findings of this study show that temperature has substantial influence on the germination of seeds of D. cinnabari. Therefore, we recommend a temperature of 30 oC to facilitate the germination of D. cinnabari, as it achieved the highest GI at this temperature relative to that at the other temperatures (22 oCC, 26 oC) applied in this study.O
Changes in Soil Aggregate Stability Induced by Mineral Nitrogen Fertilizer Application
Get PDFThe stability of soil aggregates is one of the most important characteristics of the soil affecting the overall soil quality and its health. In locality Březová nad Svitavou, experiment to reveal the effect of nitrogen dose on the stability of soil aggregates of Rendzina soil was carried out. The aim was to detect changes in soil aggregate stability after 4 and 5 years from the beginning of the experiment. There were tested 7 variants, prepared in triplicate. The results revealed that the stability of soil aggregates decreases with increasing amounts of applied N. Effect of N application was not statistically significant in the fourth but in the fifth year of the experiment. The results also revealed a significant deterioration in the stability of soil aggregates in the fifth year compared to the fourth year of the experiment.O
Impact of Added Colored Wheat Bran on Bread Quality
Get PDFThe impact of colored wheat bran addition on bread quality was tested on wheat varieties with purple pericarp (Konini, Rosso and Karkulka) and on a variety containing blue aleurone (Skorpion). The effect of 10 %, 15 % and 20 % bran addition on sensory evaluation, bread color and texture was compared to the characteristics of bread prepared from wheat variety Mulan. The addition of 10 % bran significantly increased the sensory evaluation scores of bread. Crumb characteristics were improved mainly by the addition of 10 % bran. Moreover, top-quality bread contained bran separated from wheat variety Konini.O
The Milk Thistle Seed Cakes and Hempseed Cakes are Potential Feed for Poultry
Get PDFThe aims of this work were to summarize the nutritional value of the milk thistle seed cakes and hempseed cakes and describe the influence on selected performance parameters, metabolism and animal health from inclusion of these non-traditional feeds into diets. It seems more appropriate to apply the extract of the bioactive substances complex to the livestock diets than addition of expellers or other forms of plants processing. The seed expellers, etc. mostly worsened the chickens' performance parameters with higher doses in diets, while most of the work using the extract yields had positive results on animal performance.O
Proposal of a method for the evaluation of the employment possibilities for people with special needs on woodworking machines
Get PDFThe employment opportunities for people with special needs in the field of woodworking have not yet been mapped out in the Czech Republic. All the current experience in this area has been directly acquired from individual protected and socio-therapeutic workshops. As such, the research proposes a method for evaluating the employment opportunities for handicapped people when working on woodworking machines and this has become the main contribution of the thesis. The originality of the method consists in creating a questionnaire focused on the activity under examination which has been chronologically broken into individual sub-operations for which we have determined the degree of mastery and load rate for each worker. In case of failing to carry out a sub-operation, we have proposed possible measures to remove the barrier to enable the person to carry out the operation. A model of the method has been tested with one handicapped worker. The basis for the work involved mapping out 4 protected workshops currently involved in woodworking. The research was undertaken by means of a personal visit to each individual organization and via consultation both with the leaders and with handicapped workers. Experience has shown that appropriate work adaptation enables the production of complicated wooden products such as musical instruments. The proposed method specifies the work capacity of a particular person and technology on a particular piece of machinery when machining of a specific workpiece. As such, it ascertains the real causes of the barriers restricting handicapped people from performing the work and it should lead to the consideration and proposal of work conditions which compensate for a handicap so that a person with special needs can perform the work activity in consideration. The nature of the evaluation method means that it is suitable for protected workshops, socio-therapeutic workshops and organizations producing mass-produced products.O
Overwintering of spiders in terrestrial molluscs shells in the wider area of Vranov Nad Toplou (Slovakia)
Get PDFOverwintering of spiders in empty snail shells is a little studied topic and in Slovakia similar research has not been carried out yet. Collecting shells was carried out in the eastern part of Slovakia, in winter at the turn of 2012/2013 and 2013/2014. The study was conducted both at the steppe like and post-industrial habitats. A total of 1085 shells were collected with a spider occupation rate 10.69 %. All acquired 116 spiders were classified in ten families. The most abundant spider family was the Salticidae, with a dominant species Pellenes tripunctatus (Walckenaer, 1802). Significant records include Cheiracanthium montanum (L. Koch, 1877) which is considered as vulnerable and Sitticus penicillatus (Simon, 1875) with a lower risk thread according to Red List of Slovakian spiders.O
Efficiency of Harvester with the Debarking Head at Logging in Spruce Stands Affected by Bark Beetle Outbreak
Get PDFThis paper deals with the use of debarking modifications of the conventional harvester head in the conditions of felling due to bark beetle calamity. For this purpose, a time study was established, in which the conventional heads were compared with the heads with debarking modifications on four research plots and two harvesters. The measurements were taken from August to September 2018. Harvester efficiency with the use of the head with the debarking configuration ranged from 41.2% to 41.8% from the efficiency of a machine with the conventional head, depending on the felling type. It was also demonstrated that the quality of debarking does not depend on the trunk moisture content in the growing season. In terms of diameter, it was found that the best debarked parts of the stem were those occurring in its middle. Specifically, in the central part of the stem with a diameter of 13 to 23 cm, 91.0% of the stem area was debarked in the main felling and 76.6% in the thinning. In contrast, the top parts of the stem (trunk diameter up to 13 cm) were the least debarked. In the main felling, it was 74.2% of the stem area and in the thinning, only 52.2%.O
Differentiated Estimates of Valuation Multipliers based on Price-to-Book Ratio for the Czech Brewing Industry
Get PDFThis article focuses on the differentiated estimations of industry multipliers in relation to Price-Book Value ratio (P/BV) with applying for the Czech brewing industry. Differentiation of estimates brings better approximation of these sector-wide multipliers to the defined groups companies within the given markets and thus increases the accuracy of the method of relative business valuation. Due to the absence of market data on privately held companies, the market value was assessed using the DCF method, while the book value was taken from the enterprise's accounts. The assumption of the linearity of the market-book value relationship for the subsequent calculations and differentiation of P/BV estimations was verified using regression analysis. The differentiation of P/BV ratio was made according to the size of entities, but mainly based on equality of market and book value, respectively according to the equality P/BV = 1. Then our results were supplemented by the calculation of industry P/BV ratio using P/EAT ratio and ROE decomposition. Using this additional method, the brewing industry was compared with other relevant industries in the Czech Republic.O