Search Results
You are looking at 1 - 8 of 8 items for
- Author or Editor: László Szili x
- Refine by Access: All Content x
Abstract
The aim of this paper is to continue our investigations started in [15], where we studied the summability of weighted Lagrange interpolation on the roots of orthogonal polynomials with respect to a weight function w. Starting from the Lagrange interpolation polynomials we constructed a wide class of discrete processes which are uniformly convergent in a suitable Banach space (C ρ, ‖‖ρ) of continuous functions (ρ denotes (another) weight). In [15] we formulated several conditions with respect to w, ρ, (C ρ, ‖‖ρ) and to summation methods for which the uniform convergence holds. The goal of this part is to study the special case when w and ρ are Freud-type weights. We shall show that the conditions of results of [15] hold in this case. The order of convergence will also be considered.
Abstract
Starting from the Lagrange interpolation on the roots of Jacobi polynomials, a wide class of discrete linear processes is constructed using summations. Some special cases are also considered, such as the Fejr, de la Valle Poussin, Cesro, Riesz and Rogosinski summations. The aim of this note is to show that the sequences of this type of polynomials are uniformly convergent on the whole interval [-1,1] in suitable weighted spaces of continuous functions. Order of convergence will also be investigated. Some statements of this paper can be obtained as corollaries of our general results proved in [15].
A veleszületett szívbetegségek miatt végzett szívsebészeti beavatkozások után nem ritka a ritmuszavarok megjelenése. A ritmuszavarok egy része a szívbetegség előrehaladása miatt lép fel, de jelentős hányada éppen a szívsebészeti műtétek következményeként jön létre. A gyógyszeres próbálkozások gyakran csődöt mondanak ezekben az esetekben, az intervenciós kezelés pedig bonyolult lehet az aritmia kiindulásának összetett jellege miatt. Célkitűzés és módszer: A szerzők közleményükben a veleszületett szívbetegség miatt operált betegeiknél 2004 és 2006 között végzett katéteres ablatiós beavatkozások eredményeit foglalják össze retrospektív elemzéssel. Eredmények: A vizsgált időszakban 26 esetben végeztek katéteres ablatiós beavatkozást, 24 betegnél eredményesen (92%). Kiújulás miatt ismételt beavatkozásra 3 esetben került sor (11%). Jelentős szövődményt nem észleltek, kisebb szövődmény (vérömleny a szúrás helyén) 4 esetben fordult elő. Következtetések: Ebben a betegcsoportban a katéteres ablatiók hatásásos esélyt nyújtanak a gyógyszeres kezeléssel szemben, kis megterhelést rónak a betegekre, és gyógyító eljárásnak számítanak. Ugyanakkor az összetett ritmuszavarok kezelése megfelelő szakértelmet és technológiai hátteret kíván, a klasszikus aritmiákhoz képest a beavatkozás megismétlése gyakrabban válik szükségessé.
A szimpatikus aktivitás kamrai ritmuszavarokat serkentő hatása jól ismert. Kevésbé tudott, hogy hemodinamikailag destabilizáló kamrai ritmuszavarok idején a szimpatikus aktivitásfokozódás vérnyomás-stabilizáló (protektív) szerepet játszik. Súlyos balkamra-elégtelenségben szenvedő 62 esztendős betegünk szív-elektrofiziológiai vizsgálata során a szimpatikus izom idegaktivitásának direkt mérésével demonstráltuk az arrhythmiára adott szimpatikus választ. Az eset bemutatásával a ritmuszavarok és az autonóm idegrendszer komplex kapcsolatára hívjuk fel a figyelmet.
The incidence of outbreaks of foodborne listeriosis has indicated the need for a reliable and rapid detection of the microbe in different foodstuffs. A method combining redox potential measurement and real-time polymerase chain reaction (PCR) was developed to detect Listeria monocytogenes in artificially contaminated raw milk and soft cheese. Food samples of 25 g or 25 ml were homogenised in 225 ml of Listeria Enrichment Broth (LEB) with Oxford supplement, and the redox potential measurement technique was applied. For Listeria species the measuring time was maximum 34 h. The absence of L. monocytogenes could reliably be proven by the redox potential measurement method, but Listeria innocua and Bacillus subtilis could not be differentiated from L. monocytogenes on the basis of the redox curves. The presence of L. monocytogenes had to be confirmed by real-time PCR. The combination of these two methods proved to detect < 10 cfu/g of L. monocytogenes in a cost- and time-effective manner. This method can potentially be used as an alternative to the standard nutrient method for the rapid detection of L. monocytogenes in food.
The classical ISO (2002) standard as reference method and the combination of redox potential measurement with real-time PCR technique were applied to detect Salmonella in milk, egg, broiler meat, and artificially contaminated egg samples. Food samples of 25 g were homogenized in 225 ml of RVS broth to prepare the basic suspension of the comparative tests. In the combined method the redox potential measurement technique serves as the selective enrichment system of the real-time PCR equipment. The reliable screening of Salmonella-free, negative samples by the redox potential measurement technique needed only 24 h. These negative samples determined by the PCR and the classical standard method in all cases proved to be negative as well. In case of positive redox result the Salmonella from the enriched suspension of the redox test-cell was identified by real-time PCR in 3 hours, instead of the conventional biochemical identification. Comparing our protocol to the ISO (2002) standard method, the total detection time of Salmonella presence/absence was less than 24 h contrary to the 114 h of the conventional method.
The potential effect of doxycycline on the microbial activity was investigated in three types of soil. Soil samples were spiked with doxycycline, incubated at 25°C and tested at 0, 2, 4 and 6 days after treatment. The microbiological activity of the soil was characterized by the viable count determined by plate pouring and by the time necessary to reach a defined rate of the redox-potential decrease termed as time to detection (TTD).The viable count of the samples was not changed during the storage. The TTD values, however exhibited a significant increase in the 0.2–1.6 mg/kg doxycycline concentration range compared to the untreated samples indicating concentration-dependent inhibitory effect on microbial activity. The potency of the effect was different in the 3 soil types. To describe the combined effect of the doxycycline concentration and time on the biological activity of one type of soil a mathematical model was constructed and applied.The change of microbial metabolic rate could be measured also without (detectable) change of microbial count when the traditional microbiological methods are not applicable. The applied new redox potential measurement-based method is a simple and useful procedure for the examination of microbial activity of soil and its potential inhibition by antibiotics.
