Использование модели Альтмана Z” при прогнозировании финансового положения компаний, зарегистрированных на турецкой фондовой бирже

For measuring financial performances of companies and identifying financial failure, there are a lot of models in the literature. Among these models, Z Score model is of the most used in terms of its being an accounting-based model and simple applicability. The purpose of this paper is found out whether the Z” Score model, which was revised by Altman, could be useful in making financial decisions about long-term firm value. For this purpose, panel cointegration analyzes were carried out among the variables, with the firm values of the publicly traded companies listed on the Turkish BIST (Istanbul Stock Exchange) as the independent variable and the Z” Score values as the dependent variable. Although the research is specific to Turkey, the results of the research are considered to be applicable globally, as Altman states that the Z” Score model can also be used by developing country companies. It has been proven that Altman Z” Score Model, applied in public company, has a high prediction power directed to financial success of the firms. According to the results of the analysis, 1 unit increase in the Z” Score values of the companies cause an increase of 0.353 units in the logarithmic return calculated over the firm value. Z” Score Model can be a precious indicator for heads of companies, accounting and financial managers, auditors, creditors, investors to make accurate decisions directed to assessing financial structures of companies in advance.Для измерения финансовых показателей компаний и выявления их финансового кризиса в научной литературе существует множество моделей. Среди них модель Z” Score является одной из наиболее используемых, поскольку она основана на бухгалтерском учете и проста в применении. Цель данного исследования — выяснить, применима ли модель Z” Score, усовершенствованная Альтманом, для оценки стоимости фирмы в долгосрочной перспективе. Проведен панельный анализ коинтеграции между переменными, где в качестве независимой переменной выступала стоимость компании, акции которой котируются на турецкой фондовой бирже BIST (istanbul stock exchange), а в качестве зависимой переменной — Z” Score. Несмотря на то, что исследование проводилось конкретно в Турции, его результаты считаются применимыми во всем мире, так как Альтман утверждает, что модель Z” Score может также использоваться компаниями из развивающихся стран. Доказано, что модель Altman Z” Score, примененная в отношении публичной компании, имеет высокую способность прогнозировать финансовый успех фирм. Согласно результатам анализа увеличение на 1 единицу значения Z” баллов компаний приводит к увеличению на 0,353 единицы логарифмического дохода, рассчитанного по стоимости фирмы. Модель Z Score может быть полезна для руководителей компаний, бухгалтерских и финансовых менеджеров, аудиторов, кредиторов, инвесторов при принятии верных решений, связанных с предварительной оценкой финансовых показателей компаний

Collision and symmetry-breaking in the transition to strange nonchaotic attractors

Strange nonchaotic attractors (SNAs) can be created due to the collision of an invariant curve with itself. This novel ``homoclinic'' transition to SNAs occurs in quasiperiodically driven maps which derive from the discrete Schr\"odinger equation for a particle in a quasiperiodic potential. In the classical dynamics, there is a transition from torus attractors to SNAs, which, in the quantum system is manifest as the localization transition. This equivalence provides new insights into a variety of properties of SNAs, including its fractal measure. Further, there is a {\it symmetry breaking} associated with the creation of SNAs which rigorously shows that the Lyapunov exponent is nonpositive. By considering other related driven iterative mappings, we show that these characteristics associated with the the appearance of SNA are robust and occur in a large class of systems.Comment: To be appear in Physical Review Letter

Intermittency transitions to strange nonchaotic attractors in a quasiperiodically driven Duffing oscillator

Different mechanisms for the creation of strange nonchaotic attractors (SNAs) are studied in a two-frequency parametrically driven Duffing oscillator. We focus on intermittency transitions in particular, and show that SNAs in this system are created through quasiperiodic saddle-node bifurcations (Type-I intermittency) as well as through a quasiperiodic subharmonic bifurcation (Type-III intermittency). The intermittent attractors are characterized via a number of Lyapunov measures including the behavior of the largest nontrivial Lyapunov exponent and its variance as well as through distributions of finite-time Lyapunov exponents. These attractors are ubiquitous in quasiperiodically driven systems; the regions of occurrence of various SNAs are identified in a phase diagram of the Duffing system.Comment: 24 pages, RevTeX 4, 12 EPS figure

What parathyroid hormone levels should we aim for in children with stage 5 chronic kidney disease; what is the evidence?

The bone disease that occurs as a result of chronic kidney disease (CKD) is not only debilitating but also linked to poor growth and cardiovascular disease. It is suspected that abnormal bone turnover is the main culprit for these poor outcomes. Plasma parathyroid hormone (PTH) levels are used as a surrogate marker of bone turnover, and there is a small number of studies in children that have attempted to identify the range of PTH levels that correlates with normal bone histology. It is clear that high PTH levels are associated with high bone turnover, although the range is wide. However, the ability of PTH levels to distinguish between low and normal bone turnover is less clear. This is an important issue, because current guidelines for calcium and phosphate management are based upon there being an “optimum” range for PTH. This editorial takes a critical look at the evidence upon which these recommendations are based

Succinic semialdehyde dehydrogenase deficiency: Lessons from mice and men

Succinic semialdehyde dehydrogenase (SSADH) deficiency, a disorder of GABA degradation with subsequent elevations in brain GABA and GHB, is a neurometabolic disorder with intellectual disability, epilepsy, hypotonia, ataxia, sleep disorders, and psychiatric disturbances. Neuroimaging reveals increased T2-weighted MRI signal usually affecting the globus pallidus, cerebellar dentate nucleus, and subthalamic nucleus, and often cerebral and cerebellar atrophy. EEG abnormalities are usually generalized spike-wave, consistent with a predilection for generalized epilepsy. The murine phenotype is characterized by failure-to-thrive, progressive ataxia, and a transition from generalized absence to tonic-clonic to ultimately fatal convulsive status epilepticus. Binding and electrophysiological studies demonstrate use-dependent downregulation of GABA(A) and (B) receptors in the mutant mouse. Translational human studies similarly reveal downregulation of GABAergic activity in patients, utilizing flumazenil-PET and transcranial magnetic stimulation for GABA(A) and (B) activity, respectively. Sleep studies reveal decreased stage REM with prolonged REM latencies and diminished percentage of stage REM. An ad libitum ketogenic diet was reported as effective in the mouse model, with unclear applicability to the human condition. Acute application of SGS–742, a GABA(B) antagonist, leads to improvement in epileptiform activity on electrocorticography. Promising mouse data using compounds available for clinical use, including taurine and SGS–742, form the framework for human trials

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe