Enzymatic Activities, Characteristics of Wood-Decay and Wood Substrate Specificity within Genera of Some Wood-Rotting Basidiomycetes from Cameroon and Tropical Africa

A total of 72 species of wood-rotting Basidiomycetes belonging to 40 genera, 13 families and 5 orders, were investigated in this study of which 46 for the first time as far as type of wood-rot is concerned. 61 of the 72 cause white rot (W) representing 84.72 % of the total and 11 cause brown rot (B) or just 15.27 %, confirming the predominance already known of white rot (W) on brown rot (B) as shown in other studies. Results recorded show that even though most species belonging to same genera display the same type of rot (W or B), species of some few other genera were found to rather display different types of rot (W and B) in species within the same genera. Other results show that when determining the type of wood-rot caused by some species of fungi, in case of negative (-) test using tincture of guaiac which is known as the key test to determine the type of rot, syringaldazine must also be used as a differential test before concluding whether the species is a white (W) or brown rot (B) fungus. The level of activity of tyrosinase and peroxidase shows important variations between species of some genera, whereby some species of a given genus show varying potential level (+, ++, +++, ++++) of activities of these two enzymes, whereas other species of the same genus show no sign (-) of activity of the same enzymes. Therefore, our results led to the conclusion that the presence (+, ++, +++, ++++) or absence (-) of activity of peroxidase and tyrosinase can from now onwards also be used as an enzyme linked taxonomic criteria to distinguish between species of some genera. About detection of laccases activity, if a negative (-) result occurs during detection test in a wood-rotting fungus using syringaldazine, α-naphtol must also be used as a differential test before concluding on whether the species produces laccases or not. Based on the overall results recorded in the detection of enzymes activities, it appears necessary to use, where indicated, several substrates with different chemical sensitivities to detect the existence of an enzyme and its potential activity level in a fungal species. Additionally, preliminary lists of wood-decay fungi with potentially strong (+++, ++++) capacity to produce different types of polyphenol oxidases potentially usable in paper making industries, wastewater treatment and soil remediation, are provided. With regard to the study of substrate specificity which aimed at finding out the existence or not of a specificity between polyporales and tree wood species on which they grow, the first results recorded on a limited number of trees investigated led to the preliminary conclusion that, although some few tree species may serve as hosts for only a single species of polyporales, there is rather a greater tendency of finding several species growing on different species of wood as well as the same species of wood hosting several species of polyporales. These field observations led to the remark that a much larger inventory including a greater number of tree species in various tropical ecosystems is necessary in order to come out with a final conclusion.

REKSADANA SYARIAH dan KONVENSIONAL DI INDONESIA

<p class="western" align="justify"><em><span lang="EN-US">This study aims to test the difference between the conventional mutual fund and the sharia mutual fund on performances and risk. The development of mutual fund products is based on 2 (two) categories, conventional mutual funds, and sharia mutual funds (www.ojk.go.id). Based on data from the Data Center and Statistics of Islamic Mutual Funds, the performance of Islamic mutual funds is still underperformed compared to conventional mutual funds. Therefore, testing the performance of Islamic mutual funds by testing the performance of conventional mutual funds has not been widely tested. Secondary data was used in this study with all 1425 mutual funds from 2012-2017 on the Indonesia Stock Exchange was used as the population in this study is. The purposive sampling technique determines the sample in this study. The sample used in this study was Conventional and Shariah mutual fund in Indonesia Stock Exchange (IDX) with six products each. This hypothesis test used Differential Test tools with data analysis techniques using Paired sample t-test analysis using SPSS 25. In this study, we found that there was a significant difference between the return on conventional mutual funds and Syariah mutual funds. While the risk, Sharpe method, Treynor method, and Jensen method have not significant difference between conventional mutual funds and Syariah mutual funds.</span></em></p>

A New Investigation of Fake Resistance of a Multidimensional Forced-Choice Measure: An Application of Differential Item/Test Functioning

To address faking issues associated with Likert-type personality measures, multidimensional forced-choice (MFC) measures have recently come to light as important components of personnel assessment systems. Despite various efforts to investigate the fake resistance of MFC measures, previous research has mainly focused on the scale mean differences between honest and faking conditions. Given the recent psychometric advancements in MFC measures (e.g., Brown & Maydeu-Olivares, 2011; Stark et al., 2005; Lee et al., 2019; Joo et al., 2019), there is a need to investigate the fake resistance of MFC measures through a new methodological lens. This research investigates the fake resistance of MFC measures through recently proposed differential item functioning (DIF) and differential test functioning (DTF) methodologies for MFC measures (Lee, Joo, & Stark, 2020). Overall, our results show that MFC measures are more fake resistant than Likert-type measures at the item and test levels. However, MFC measures may still be susceptible to faking if MFC measures include many mixed blocks consisting of positively and negatively keyed statements within a block. It may be necessary for future research to find an optimal strategy to design mixed blocks in the MFC measures to satisfy the goals of validity and scoring accuracy. Practical implications and limitations are discussed in the paper.

Testing for Differential Item Functioning Under the D-Scoring Method

This study offers an approach to testing for differential item functioning (DIF) in a recently developed measurement framework, referred to as D-scoring method (DSM). Under the proposed approach, called P–Z method of testing for DIF, the item response functions of two groups (reference and focal) are compared by transforming their probabilities of correct item response, estimated under the DSM, into Z-scale normal deviates. Using the liner relationship between such Z-deviates, the testing for DIF is reduced to testing two basic statistical hypotheses about equal variances and equal means of the Z-deviates for the reference and focal groups. The results from a simulation study support the efficiency (low Type error and high power) of the proposed P–Z method. Furthermore, it is shown that the P–Z method is directly applicable in testing for differential test functioning. Recommendations for practical use and future research, including possible applications of the P–Z method in IRT context, are also provided.

FEATURES OF REFLECTION AND STYLE OF DECISION-MAKING IN ADOLESCENTS

The article presents the results of a study of the features of reflection and the type of decision-making in adolescents. The sample was 60 people (55% girls, 45% boys). It were used the questionnaire «Differential Test of Reflection» (D.A. Leontiev et al.) and «Melbourne decision-making questionnaire» (T.V. Kornilova). The results showed the predominance of quasi-reflection, which manifests itself in idle speculation on insignificant life events, as well as a low level of development of systemic reflection. The preferred style of decision-making is procrastination, which means postpone solutions. Correlation analysis allowed us to confirm the hypothesis that the level of systemic reflection increases with age. At the same time, a positive correlation was found between systemic reflection and such a decision-making style as «avoidance». We assume the influence of an unaccounted variable.

Psychology of rest and problems of human functional states’ self-regulation^ proactive and reactive approaches

The different attitudes to rest and recovery are discussed and analyzed on the base of the empirical study. The aim of the study — to identify the link between employees attitudes to rest and the typical means of human functional states’ (HFS) self-regulation in dynamic organizational environment. Employees of different service organizations with flexible work schedule participated in the study. The diagnostic set included: special check-lists for peculiarities of rest and recovery planning; the semantic differential test; questionnaires to get data about typical self-regulation and coping means, used under work pressure. The obtained data helped to reveal that attitudes towards rest and recovery are tightly connected with proactive or reactive approaches to rest planning. Employees with proactive approach to rest planning demonstrated better recovery in comparison with employees with reactive approach. “Proactive” employees tend to use various types of self-regulation and coping means under work tension. For “reactive” employees typical self-regulation and coping means are related with emotional abreaction and communications with colleagues.