Factors affecting Corporate Cash Holdings: A study of Non-financial Institutions Listed on the Ghana Stock Exchange.

This article intended to investigate the determinates of cash holding of registered non-financial institutions (NFIs) on the Ghana Stock Exchange (GSE). The research used panel data obtained from the twenty-five enterprises, for the period 2012-2018. The article adopted the robust fixed effect regression technique to empirically find the determinates of cash holdings. The research findings indicated an adverse nexus between cash holdings and capital structure. The profitability of the enterprise shown a positive and significant affiliation with industry cash holdings. Similarly, the size of the firms exhibited statistically a significant connection with enterprise cash holdings. The interest rate and inflation rate both indicated a positive and negative link. The article results are of significant source for enterprises registered on the GSE market to make the proper decision on the volume of cash to hold Keywords: Cash holdings, robust fixed effects, leverage, Non-financial institutions, profitability. DOI: 10.7176/RJFA/11-18-18 Publication date:September 30th 202

Earnings Management and Corporate Performance: An Empirical Evidence from Ghana

This study aimed at assessing the impact earnings management has on corporate performance of firms on the Ghana Stock Exchange. The study used discretionary accruals of the modified jones model, abnormal cashflow from operations, abnormal discretionary expenses and abnormal production cost to measure earnings management whiles corporate performance was measured using return on assets. The study used a sample of 14 listed companies on the Ghana Stock Exchange (GSE) for the period of 2008 to 2018. We applied multiple linear regression for hypothesis testing. The findings of the study indicate that firm listed on the GSE engages earnings management and manages earnings upwards. Our results indicate earnings management through both accrual earnings and real earnings management techniques have a significant positive effect on corporate performance. Therefore, we recommend an intensive evaluation by the users of financial statements to make competent decisions. Keywords: Accrual Earnings Management, Real Earnings Management, Discretionary Accruals, Corporate Performance DOI: 10.7176/RJFA/11-10-01 Publication date:May 31st 202

The significance of log and boulder steps for diversification of fluvial sediments characteristics in a stream channel in a small forest catchment in the Polish Carpathians

The study presents the diversification of sediments deposited on log (LS), boulder (BS) and mixed-type (LBS) steps located in the channel of a stream in a small forest mountain catchment in the Polish Carpathians. The topic of sediment diversification in a stream channel is an important issue not only from the perspective of sediment transport process and shaping fluvial systems in forested catchments caused by woody or rock debris but also in the context of functioning of local ecosystems. We aimed to test the following hypothesis: the morphodynamic features of a stream channel and the type of steps therein significantly affect the diversification of the size and shape of mineral deposits and play an important role in the process of sediments transport and processing in the channels of small mountain streams. In order to verify the above hypothesis, sediments were sampled directly from the stream channel (Ch) in its longitudinal profile as well as upstream and downstream of steps (LS, BS and LBS) in the channel. The diversification of features of sediment grain size was analysed taking into account step type and sediment location in the longitudinal profile of the stream channel. The research was conducted separately for fine-grained sandstone (A) and coarse-grained sandstone (B). In addition, the basic sedimentological indicators and the shape parameter of the gravels, as described by the Zingg method, were determined. In order to determine the transport predisposition of the sediments in a specific load, an analysis of sediment distribution was performed on the C/M (C-first percentile and M-median) diagram. The PCA (Principal component analysis) analysis showed that the step type significantly affects the processing as well as the size and shape diversification of mineral deposits, which confirms our hypothesis. Therefore, this study is a contribution to the current knowledge on fluvial processes occurring in stream channels in small forest mountain catchments

Equivalence between two charged black holes in dynamics of orbits outside the event horizons

Using the FermiDirac distribution function, Balart and Vagenas gave a charged spherically symmetric regular black hole, which is a solution of Einstein field equations coupled to a nonlinear electrodynamics. In fact, the regular black hole is a Reissner-Nordstrom (RN) black hole when a metric function is given a Taylor expansion to first order approximations. It does not have a curvature singularity at the origin,but the RN black hole does. Both black hole metrics have horizons and similar asymptotic behaviors, and satisfy the weak energy conditions everywhere. They are almost the same in photon effective potentials, photon circular orbits and photon spheres outside the event horizons. There are relatively minor differences between effective potentials, stable circular orbits and innermost stable circular orbits of charged particles outside the event horizons of the two black holes immersed in external magnetic fields. Although the twomagnetized black holes allow different construction methods of explicit symplectic integrators, they exhibit approximately consistent results in the regular and chaotic dynamics of charged particles outside the event horizons. Chaos gets strong as the magnetic field parameter or the magnitude of negative Coulomb parameter increases, but becomes weak when the black hole charge or the positive Coulomb parameter increases. A variation of dynamical properties is not sensitive dependence on an appropriate increase of the black hole charge. The basic equivalence between the two black hole gravitational systems in the dynamics of orbits outside the event horizons is due to the two metric functions having an extremely small difference. This implies that the RN black hole is reasonably replaced by the regular black hole without curvature singularity in many situations.Comment: 18 pages, 12 figure

T-COL: Generating Counterfactual Explanations for General User Preferences on Variable Machine Learning Systems

Machine learning (ML) based systems have been suffering a lack of interpretability. To address this problem, counterfactual explanations (CEs) have been proposed. CEs are unique as they provide workable suggestions to users, in addition to explaining why a certain outcome was predicted. However, the application of CEs has been hindered by two main challenges, namely general user preferences and variable ML systems. User preferences, in particular, tend to be general rather than specific feature values. Additionally, CEs need to be customized to suit the variability of ML models, while also maintaining robustness even when these validation models change. To overcome these challenges, we propose several possible general user preferences that have been validated by user research and map them to the properties of CEs. We also introduce a new method called \uline{T}ree-based \uline{C}onditions \uline{O}ptional \uline{L}inks (T-COL), which has two optional structures and several groups of conditions for generating CEs that can be adapted to general user preferences. Meanwhile, a group of conditions lead T-COL to generate more robust CEs that have higher validity when the ML model is replaced. We compared the properties of CEs generated by T-COL experimentally under different user preferences and demonstrated that T-COL is better suited for accommodating user preferences and variable ML systems compared to baseline methods including Large Language Models

Study on Spatial Distribution of Soil Available Microelement in Qujing Tobacco Farming Area, China

AbstractDescriptive analysis characteristics and spatial variation characteristics of soil available microelements were studied based on SPSS and GIS Soil available microelements spatial distribution maps were created with ordinary Kriging method. The results indicate that, 7 available microelements in tobacco soil obey lognormal distribution, all the available microelements were intermediate variability; Anisotropic structure of available microelements of tobacco soil varies evidently, spatial variability of available B was mainly caused by random factors, and others’ spatial variability were caused by structural factors and random factors; Spatial distribution maps show that, available B was widely deficient in tobacco soil of Qujing farming area, ‘lower level’ and ‘low level’ taken 7.74% and 68.20%, respectively available Zn distribution was moderate, only 1.32% of the area lack of Zn, available Cu, available Fe and available Mn were extremely high in the whole extension, available Mo was deficient in part of the region with 28.38%, water soluble Cl was higher than critical value(30mgkg−1)in the most of Qujing farming area, which taken 38.86%

Nonlinear optical properties in a quantum well with the hyperbolic confinement potential

We have performed theoretical calculation of the nonlinear optical properties in a quantum well (QW) with the hyperbolic confinement potential. Calculation results reveal that the transition energy, oscillator strength, second-order nonlinear optical rectification (OR), geometric factor and nonlinear optical absorption (OA) are strongly affected by the parameters ($\alpha, \sigma$) of the hyperbolic confinement potential. And an increment of the parameter $\alpha$ reduces all these physical quantities, while an increment of the parameter $\sigma$ enhances them, but not for geometric factor. In addition, it is found that one can control the optical properties of QW by tuning these parameters.Comment: 16pages,6 figures,Accepted for publication in Physica

A Biodegradable Polyethylenimine-Based Vector Modified by Trifunctional Peptide R18 for Enhancing Gene Transfection Efficiency In Vivo

Lack of capacity to cross the nucleus membrane seems to be one of the main reasons for the lower transfection efficiency of gene vectors observed in vivo study than in vitro. To solve this problem, a new non-viral gene vector was designed. First, a degradable polyethylenimine (PEI) derivate was synthesized by crosslinking low-molecular-weight (LMW) PEI with N-octyl-N-quaternary chitosan (OTMCS), and then adopting a designed trifunctional peptide (RGDC- TAT-NLS) with good tumor targeting, cell uptake and nucleus transport capabilities to modify OTMCS-PEI. The new gene vector was termed as OTMCS- PEI-R18 and characterized in terms of its chemical structure and biophysical parameters. Gene transfection efficiency and nucleus transport mechanism of this vector were also evaluated. The polymer showed controlled degradation and remarkable buffer capabilities with the particle size around 100–300 nm and the zeta potential ranged from 5 mV to 40 mV. Agraose gel electrophoresis showed that OTMCS-PEI-R18 could effectively condensed plasmid DNA at a ratio of 1.0. Besides, the polymer was stable in the presence of sodium heparin and could resist digestion by DNase I at a concentration of 63U DNase I/DNA. OTMCS-PEI-R18 also showed much lower cytotoxicity and better transfection rates compared to polymers OTMCS-PEI-R13, OTMCS-PEI and PEI 25 KDa in vitro and in vivo. Furthermore, OTMCS-PEI-R18/DNA complexes could accumulate in the nucleus well soon and not rely on mitosis absolutely due to the newly incorporated ligand peptide NLS with the specific nuclear delivery pathway indicating that the gene delivery system OTMCS-PEI-R18 could reinforce gene transfection efficiency in vivo