32 research outputs found
Cechy dystynktywne
Three methods for distinctive (independent) features determination were designed and implemented in computer programs. Two of them were based on the assumption that the maximum number of the dependent variable’s values cannot exceed the number of the points of the variable space. Using the third method, some functional relations between a priori chosen dependent features and the sets of a priori chosen independent features were studied. The main purpose of another method was to determine the minimum sets of features necessary to distinguish individual objects in a given set. It allowed to evaluate features’ “load” (how often they were used in the task of object’s distinguishing). In this way, any complex functional relations of any number of categorical features which can take any number of values can be determined. Possible applications vary from optimizing phones’ description in the articulatory space, to the optimal selection of graphical features of different alphabets’ signs, and database normalization
The role of antioxidant response and nonphotochemical quenching of chlorophyll fluorescence in long-term adaptation to Cu-induced stress in Chlamydomonas reinhardtii
Copper is an essential micronutrient, but at supraoptimal concentrations it is also highly toxic, inducing oxidative stress and disrupting photosynthesis. The aim of the present study was to analyze selected protective mechanisms in strains of Chlamydomonas reinhardtii adapted and not adapted for growth in the presence of elevated copper concentrations. Two algal lines (tolerant and non-tolerant to high concentrations) were used in experiments to study photosynthetic pigment content, peroxidase activity, and non-photochemical quenching. The content of prenyllipids was studied in four different algal lines (two of the same as above and two new ones). The copper-adapted strains contained about 2.6 times more α-tocopherol and plastoquinol and about 1.7 times more total plastoquinone than non-tolerant strains. Exposure to excess copper led to oxidation of the plastoquinone pool in non-tolerant strains, whereas this effect was less pronounced or did not occur in copper-tolerant strains. Peroxidase activity was approximately 1.75 times higher in the tolerant strain than in the non-tolerant one. The increase in peroxidase activity in the tolerant strain was less pronounced when the algae were grown in dim light. In the tolerant line nonphotochemical quenching was induced faster and was usually about 20-30% more efficient than in the non-tolerant line. The improvement of antioxidant defense and photoprotection may be important factors in the evolutionary processes leading to tolerance to heavy metals
Copper excess-induced large reversible and small irreversible adaptations in a population of Chlamydomonas reinhardtii CW15 (Chlorophyta)
Two Chlamydomonas reinhardtii CW15 populations modified by an excess of copper in growth medium were obtained: a “Cu” population that was continuously grown under the selection pressure of 5 µM Cu2+ (for at least 48 weeks) and the “Re” population, where a relatively short (9 week) exposure to elevated copper, necessary for acquiring tolerance, was followed by a prolonged period (at least 39 weeks) of cultivation at a normal (0.25 µM) copper concentration.
Cells of the Cu population were able to multiply at a Cu2+ concentration 16 times higher than that of the control population at a normal light intensity and at a Cu2+ concentration 64 times higher when cultivated in dim light. The potential quantum yield of photosystem II (FV/FM ratio) under copper stress was also significantly higher for the Cu population than for Re and control populations.
The Re population showed only residual tolerance towards the elevated concentration of copper, which is revealed by an FV/FM ratio slightly higher than in the control population under Cu2+ stress in dim light or in darkness.
We postulate that in the Chlamydomonas populations studied in this paper, at least two mechanisms of copper tolerance operate. The first mechanism is maintained during cultivation at a standard copper concentration and seems to be connected with photosynthetic apparatus. This mechanism, however, has only low adaptive value under excess of copper. The other mechanism, with a much higher adaptive value, is probably connected with Cu2+ homeostasis at the cellular level, but is lost during cultivation at a normal copper concentration
Contemporary determinants of international relatioos
Z wprowadzenia: "Nauka o stosunkach międzynarodowych nie może się obejść bez systematyzowania
i porządkowania omawianej przez siebie niezwykle szerokiej materii.
Poszukując odpowiedzi na pytania związane z relacjami pomiędzy
uczestnikami interakcji międzynarodowych, nie sposób nie dostrzegać czynników,
jakie na nie wpływają, czy to w sposób pośredni czy też bezpośredni,
zależny lub niezależny od nich. Wielość tych czynników i zmienność wagi
przykładanej do poszczególnych, zależnie od epoki, stwarza konieczność
gruntownego badania i wskazywania na najważniejsze z nich, decydujące
w danym okresie."(...
Subarachnoid Space: New Tricks by an Old Dog
PURPOSE: The purpose of the study was to: (1) evaluate the subarachnoid space (SAS) width and pial artery pulsation in both hemispheres, and (2) directly compare magnetic resonance imaging (MRI) to near-infrared transillumination/backscattering sounding (NIR-T/BSS) measurements of SAS width changes in healthy volunteers. METHODS: The study was performed on three separate groups of volunteers, consisting in total of 62 subjects (33 women and 29 men) aged from 16 to 39 years. SAS width was assessed by MRI and NIR-T/BSS, and pial artery pulsation by NIR-T/BSS. RESULTS: In NIR-T/BSS, the right frontal SAS was 9.1% wider than the left (p<0.01). The SAS was wider in men (p<0.01), while the pial artery pulsation was higher in women (p<0.01). Correlation and regression analysis of SAS width changes between the back- and abdominal-lying positions measured with MRI and NIRT-B/SS demonstrated high interdependence between both methods (r = 0.81, p<0.001). CONCLUSIONS: NIR-T/BSS and MRI were comparable and gave equivalent modalities for the SAS width change measurements. The SAS width and pial artery pulsation results obtained with NIR-T/BSS are consistent with the MRI data in the literature related to sexual dimorphism and morphological asymmetries between the hemispheres. NIR-T/BSS is a potentially cheap and easy-to-use method for early screening in patients with brain tumours, increased intracranial pressures and other abnormalities. Further studies in patients with intracranial pathologies are warranted
Multicenter registry of Impella-assisted high-risk percutaneous coronary interventions and cardiogenic shock in Poland (IMPELLA-PL)
Background: Impella is a percutaneous mechanical circulatory support device for treatment of cardiogenic shock (CS) and high-risk percutaneous coronary interventions (HR-PCIs). IMPELLA-PL is a national retrospective registry of Impella-treated CS and HR-PCI patients in 20 Polish interventional cardiological centers, conducted from January 2014 until December 2021.Aims: We aimed to determine the efficacy and safety of Impella using real-world data from IMPELLA-PL and compare these with other registries.Methods: IMPELLA-PL data were analyzed to determine primary endpoints: in-hospital mortality and rates of mortality and major adverse cardiovascular and cerebrovascular events (MACCE) at 12 months post-discharge.Results: Of 308 patients, 18% had CS and 82% underwent HR-PCI. In-hospital mortality rates were 76.4% and 8.3% in the CS and HR-PCI groups, respectively. The 12-month mortality rates were 80.0% and 18.2%, and post-discharge MACCE rates were 9.1% and 22.5%, respectively. Any access site bleeding occurred in 30.9% of CS patients and 14.6% of HR-PCI patients, limb ischemia in 12.7% and 2.4%, and hemolysis in 10.9% and 1.6%, respectively.Conclusions: Impella is safe and effective during HR-PCIs, in accordance with previous registry analyses. The risk profile and mortality in CS patients were higher than in other registries, and the potential benefits of Impella in CS require investigation
The Optimal Tolerance Solution of the Basic Interval Linear Equation and the Explanation of the Lodwick’s Anomaly
Determining the tolerance solution (TS) of interval linear systems (ILSs) has been a task under consideration for many years. It seems, however, that this task has not been fully and unequivocally solved. This is evidenced by the multiplicity of proposed methods (which sometimes provide different results), the existence of many questions, and the emergence of strange solutions provided by, for example, Lodwick’s interval equation anomaly (LIEA). The problem of solving ILEs is probably more difficult than we think. The article presents a new method of ILSs solving, but it is limited to the simplest, basic equation [a̲,a¯]X=[b̲,b¯], which is an element of all more complex forms of ILSs. The method finds the optimal TS for this equation by using multidimensional interval arithmetic (MIA). According to the authors’ knowledge, this is a new method and it will allow researchers to solve more complex forms of ILSs and various types of nonlinear interval equations. It can also be used to solve fuzzy linear systems (FLSs). The paper presents several examples of the method applications (including one real-life case)
Realistic Optimal Tolerant Solution of the Quadratic Interval Equation and Determining the Optimal Control Decision on the Example of Plant Fertilization
In scientific journals, it is increasingly common to find articles presenting methods for solving problems not based on idealistic mathematical models containing perfectly accurate coefficient values that cannot be obtained in practice, but on models in which coefficient values are affected by uncertainty and are expressed in the form of intervals, fuzzy numbers, etc. However, solving tasks with interval coefficients is not fully mastered, and a number of such problems cannot be solved by currently known methods. There is undeniably a research gap here. The article presents a method for solving problems governed by the quadratic interval equation and shows how to find the tolerant optimal control value of such a system. This makes it possible to solve problems that could not be solved before. The paper introduces a new concept of the degree of robustness of the control to the set of all possible multidimensional states of the system resulting from its uncertainties. The method presented in the article was applied to an example of determining the optimal value of nitrogen fertilization of a sugar beet plantation, the vegetation of which is under uncertainty. It would be unrealistic to assume precise knowledge of crop characteristics here. The proposed method allows to determine the value of fertilization, which gives a chance to obtain the desired yield for the maximum number of field conditions that can occur during the growing season