Simulation discounted cash flow valuation for internet companies

Discounted cash flow (DCF) is the most accepted approach for company valuation. It is well grounded in theory and practice. However, the DCF approach, which is commonly used for traditional companies valuation, presents a number of serious weaknesses within the Internet companies’ context. One of these weaknesses is tackling the uncertainty that characterize future cash flows of these companies. Specifically DCF assumes that future cash flow streams are highly predictable. The effects of uncertainty are therefore tackled implicitly by discounting the expected value of the cash flows at a risk-adjusted interest rate. However, under uncertainty, future cash flows of these companies can no longer be characterized by a single value but rather by a range of values of its possible consequences. This paper looks at the way in which uncertainty can be incorporated into the traditional DCF approach so that the latter, which is otherwise conceptually sound, becomes relevant. This is done by recognizing that the DCF input variables are uncertain and will have a probability distribution pertaining to each of them. Thus by utilizing a probability-based valuation model (using Monte Carlo Simulation) it is possible to incorporate uncertainty into the analysis and address the shortcomings of the current model. The MC simulation assigns a range of values in order to cope with uncertainty underlies each key cash flow variable. The process leads to a probability distribution of the valuation criterion used, giving investors a quantitative measure of risk involved

Some issues of regional development and planning in Libya

Thesis (M.A.)--Boston UniversityThis thesis is primarily concerned with the issues of regional development as they relate to a classic problem of underdevelopment, namely, the dualism of the space economy. The reversal of regional imbalance becomes a complex problem because the polarizing process is historically conditioned and is deeply ingrained into the structural economy. Accordingly, the present study of regional development in Libya started with a historical analysis of the space economy. Understanding of the historical evolution of regional economic relations is essential for the contemporary purposes of formulating development plans for modern Libya. Against a painful background of poverty resulting from historical influences and geographical constraints, the Libyan economy has experienced the "oil boom" of the Sixties. Since then, Libya has been characterized by a large capital surplus, as it became one of the major oil producing and exporting nations of the world. However, despite the abundance of capital the economy still reflects the classic structural traits of underdevelopment, i.e., sectoral imbalance and overdependence on a single product. While the oil industry has been developed extensively, other sectors of the economy remained comparatively less developed. In addition to that, the new oil wealth initiated the following problems: 1) the extension of a modern market economy into the traditional subsistence economy, disrupting the life-styles and the population base of the latter; 2) a widening gap between the rapidly growing modern cities and the stagnation or slow growth in rural areas; and 3) increased rural-to-urban migration. Given the fact that oil is an extractive economy of a nonrenewable resource, this research stresses the need for regional population policies that would link the exploitation of oil with areally dispersed industrial and agricultural activities. In this respect, population data from 1954 to 1973 were analyzed in order to identify the growing and declining regions. This analysis was supplemented by a spatial analysis of hierarchical service-centers in order to identify the gaps in space and in the hierarchical order. The results of this investigation were used to suggest a settlement policy for northeastern Libya

Control of hyperphosphatemia in regular hemodialysis (HDx) patients by calcium acetate (CA) versus calcium carbonate (CC). A double blind crossover prospective study

This study included fourty chronic renal failure patients aged 37-83 years (mean 51.3±7) on thrice weekly HDx for 4-144 month (Kt/V >1.2). Acetate dialysate with calcium concentration of 3 mEq/L was used. All phosphate binders were discontinued for one month. Patients were divided in two groups. Group I (20 cases) received CA, while group II (20 cases) received CC in equimolar dose (10 mmol, of either t.i.d.) for one month. Crossover of treatment was done for another month while keeping patients on the same diet.Serum levels of total calcium (Ca), ionized Ca (iCa), phosphorus (P), alkaline phosphates (AP), urea (U), creatinine (Cr), ALT, AST, total proteins (TP) and albumin (Alb) were estimated before, and at the end of each month of CA and CC treatment. Serum Ca and iCa were significantly lower in group I after CA compared to values after CC (p<0.01). Similar results in Ca levels were observed in group II (P<0.05). In group II only serurn P was significantly lower after CA compared to its values after CC (P<0.05). There was no significant difference in AP, U, Cr, ALT, AST, TP and Alb before, and at the end of each month of CA and CC treatment (P>0.05 in all). We excluded 12.5% of cases due to CA intolerance while non of cases had similar intolerance to CC.Conclusion: 1) CA is not very superior to CC in control of hyperphosphataemia. 2) CA can be safely increased without the risk of hypercalcemia. 3) Active Vitamin D and high dialysate Ca can be used to suppress parathyroid activity more safely with CA than with CC. 4) Tolerability to CC is superior

Maximum power point tracking techniques for photovoltaic systems: a comparative study

Photovoltaic systems (PV) are one of the most important renewable energy resources (RER). It has limited energy efficiency leading to increasing the number of PV units required for certain input power i.e. to higher initial cost. To overcome this problem, maximum power point tracking (MPPT) controllers are used. This work introduces a comparative study of seven MPPT classical, artificial intelligence (AI), and bio-inspired (BI) techniques: perturb and observe (P&O), modified perturb and observe (M-P&O), incremental conductance (INC), fuzzy logic controller (FLC), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and cuckoo search (CS). Under the same climatic conditions, a comparison between these techniques in view of some criteria’s: efficiencies, tracking response, implementation cost, and others, will be performed. Simulation results, obtained using MATLAB/SIMULINK program, show that the MPPT techniques improve the lowest efficiency resulted without control. ANFIS is the highest efficiency, but it requires more sensors. CS and ANN produce the best performance, but CS provided significant advantages over others in view of low implementation cost, and fast computing time. P&O has the highest oscillation, but this drawback is eliminated using M-P&O. FLC has the longest computing time due to software complexity, but INC has the longest tracking time

Z3-graded Grassmann Variables, Parafermions and their Coherent States

A relation between the $Z_3$-graded Grassmann variables and parafermions is established. Coherent states are constructed as a direct consequence of such a relationship. We also give the analog of the Bargmann-Fock representation in terms of these Grassmann variables.Comment: 8 page

Forecasting Remission Time of a Treatment Method for Leukemia as an Application to Statistical Inference Approach

In this paper, Weibull-Linear Exponential distribution (WLED) has been investigated whether being it is a well - fit distribution to a clinical real data. These data represent the duration of remission achieved by a certain drug used in the treatment of leukemia for a group of patients. The statistical inference approach is used to estimate the parameters of the WLED through the set of the fitted data. The estimated parameters are utilized to evaluate the survival and hazard functions and hence assessing the treatment method through forecasting the duration of remission times of patients. A two-sample prediction approach has been applied to obtain a predictive sample based on the Bayes estimates of the parameters. The statistical inference approach is applied to the case of censored data namely Type-II hybrid censoring scheme, which is common in clinical studies

Tioconazole and Chloroquine Act Synergistically to Combat Doxorubicin-Induced Toxicity via Inactivation of PI3K/AKT/mTOR Signaling Mediated ROS-Dependent Apoptosis and Autophagic Flux Inhibition in MCF-7 Breast Cancer Cells.

Cancer is a complex devastating disease with enormous treatment challenges, including chemo- and radiotherapeutic resistance. Combination therapy demonstrated a promising strategy to target hard-to-treat cancers and sensitize cancer cells to conventional anti-cancer drugs such as doxorubicin. This study aimed to establish molecular profiling and therapeutic efficacy assessment of chloroquine and/or tioconazole (TIC) combination with doxorubicin (DOX) as anew combination model in MCF-7 breast cancer. The drugs are tested against apoptotic/autophagic pathways and related redox status. Molecular docking revealed that chloroquine (CQ) and TIC could be potential PI3K and ATG4B pathway inhibitors. Combination therapy significantly inhibited cancer cell viability, PI3K/AkT/mTOR pathway, and tumor-supporting autophagic flux, however, induced apoptotic pathways and altered nuclear genotoxic feature. Our data revealed that the combination cocktail therapy markedly inhibited tumor proliferation marker (KI-67) and cell growth, along with the accumulation of autophagosomes and elevation of LC3-II and p62 levels indicated autophagic flux blockage and increased apoptosis. Additionally, CQ and/or TIC combination therapy with DOX exerts its activity on the redox balance of cancer cells mediated ROS-dependent apoptosis induction achieved by GPX3 suppression. Besides, Autophagy inhibition causes moderately upregulation in ATGs 5,7 redundant proteins strengthened combinations induced apoptosis, whereas inhibition of PI3K/AKT/mTOR pathway with Beclin-1 upregulation leading to cytodestructive autophagy with overcome drug resistance effectively in curing cancer. Notably, the tumor growth inhibition and various antioxidant effects were observed in vivo. These results suggest CQ and/or TIC combination with DOX could act as effective cocktail therapy targeting autophagy and PI3K/AKT/mTOR pathways in MCF-7 breast cancer cells and hence, sensitizes cancer cells to doxorubicin treatment and combat its toxicity

Context of STEM Integration in Schools: Views from In-service Science Teachers

This is the final version of the article. Available from ISER publications via the DOI in this record.This study explores science teachers' views regarding Science, Technology, Engineering and Mathematics (STEM) pedagogy and its interdisciplinary nature. It also seeks to identify teachers' views on the contextual factors that facilitate and hinder such pedagogy in their schools. Qualitative methodologies were used through focus group discussions and an interview protocol. From the specific contextual issues that were highlighted in the findings, was teacher self-efficacy, pedagogical-knowledge, issues related to establishing a collaborative school culture and familiarity to STEM education among school administrators, students and parents. Findings expressed teachers' concerns of their under- preparedness to enact STEM practices and illustrated that engineering is the least mentioned discipline to be integrated with science. The study ends with recommendations that could lead to develop a professional development model to enact STEM education in schools based on valuing partnership with universities and industries as a necessary step for enacting a STEM integrated model.This research was conducted as part of the professional development for in-service Science and mathematics teachers Research group with support of the Excellence Research Centre of Science and Mathematics Education - King Saudi University, Kingdom of Saudi Arabia

Quantum Correlations Dynamics In Two Coupled Semiconductor InAs Quantum Dots

We investigate the dynamics of quantum discord and concurrence between two excitonic qubits placed inside two coupled semiconductor quantum dots independently interacting with dephasing reservoirs. We explore their behavior against the dimensionless time and the temperature in both Markovian and non-Markovian environments. Moreover, we analyze the external electric field effects and the F\"orster interaction effects on these correlations. We show that, although the quantum correlations amount is strongly influenced by the variation of the electric field and the F\"orster interaction, their non-Markovian behavior is still preserved under the variation of these two parameters. Furthermore, we show that for large values of temperature and dimensionless time, unlike concurrence which vanishes, nonzero discord can still be observed.Comment: 15 pages, 12 figure