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1

Preventive vaccination of foxes against rabies – economic and environmental aspects

Flis M.

Ekonomia i Środowisko

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2018

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nr 1

220--230

EN

The thesis presents the analysis of the oral immunization effectiveness, taking cognizance of wild foxes. The preventive measures conducted 15 years ago have significantly contributed to the substantial decline in the number of verified cases of rabies among wild and domestic animals. Despite the fact, that aforementioned measures have been generating high costs covered by the state’s founds, they dramatically reduced the risk of epizootic danger, thus epidemiological risks. Undertaken actions also led to the dynamic growth of population of foxes, which resulted in a kind of disruption of natural ecological system concerning the ‘predator – prey’ relation, therefore they have indirectly contributed to the deepening of the already ongoing contraction of the basic small animals.

2

Portfolio immunization under cone restrictions

Gajek L., Krajewska E.

Journal of Applied Analysis

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2017

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Vol. 23, nr 2

127--135

EN

Interest rate risk for portfolios with random cash flows is mitigated via minimizing its L2-measure. A link between monotonicity of linear operators and immunization under cone restrictions is examined. The results are based on the Hilbert space methods applied to incomplete markets.

3

Immunization Effect of Sodium Aluminate on Wool

Sirvaityte J., Beleska K., Alaburdaite R., Komiciute I., Valeika V.

Fibres & Textiles in Eastern Europe

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2017

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Vol. 25, no. 5 (125)

42--46

EN

Since the environmental requirements for leather manufacture as well as for other industry branches are becoming stricter, investigations of unhairing have been directed towards conditions of the process which allow the saving of hair: enzymatic unhairing or unhairing with hair immunization conventionally achieved by using lime and sodium sulphide. The problem is that lime forms a big quantity of liquid waste which contains lime sludge polluted by sulphides and protein degradation products. The research is devoted to the replacement of Ca(OH)2 as hair immunization material with some other soluble non-hazardous material with a similar immunization effect. The preliminary tests showed that alkaline sodium aluminate suits this purpose very well. Its immunisation efficiency increases with prolonged treatment duration and increased concentration of the treatment solution. Treatment with 20 g/l of sodium silicate solution for 3 h allows to reach a high immunization ability almost the same as that of calcium hydroxide under the same conditions. The immunisation effect lasts when the pH is approx. 13.

PL

Ponieważ normy dotyczące ochrony środowiska w przemyśle skórzanym, jak również w innych gałęziach przemysłu stają się coraz bardziej restrykcyjne, badano immunizację wełny wodorotlenkami wapnia i potasu oraz metaglinianem sodu, badając poziom degradacji wełny po obróbce. Efekt immunizacji został oszacowany na podstawie zmian utraty masy wełny i zawartości azotu w roztworze. Potwierdzono, że metaglinian sodu jest skutecznym środkiem immunizującym. Skuteczność immunizacji metaglinianem sodu zwiększa się wraz z wydłużeniem czasu obróbki i zwiększeniem stężenia roztworu.

4

Assets/liabilities portfolio immunization as an optimization problem

Kondratiuk-Janyska A., Kałuszka M.

Control and Cybernetics

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2006

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Vol. 35, no 2

335-349

EN

The aim of this paper is to present bond portfolio immunization strategies in the case of multiple liabilities, based on single-risk or multiple-risk measure models under the assumption of multiple shocks in the term structure of interest rates referring, in particular, to Fong and Vasicek (1984), Nawalkha and Chambers (1996), Balbas and Ibanez (1998) and Hurlimann (2002). Immunization problem is formulated as a constrained optimization problem under a fixed open loop strategy. New risk measures associated with changes of the term structure are also defined.

5

Construction of a k-immunization strategy with the highest convexity

Zaremba L.

Control and Cybernetics

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1998

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Vol. 27, no 1

135-144

EN

Assuming that interest rate shocks are proportional to their values plus one, we prove in Theorem 1 the existence of and construct a portfolio Z[sup *] with the highest convexity in the class of portfolios that solve the immunization problem to meet the liability to pay C dollars K years from now. Z[sup *] appears to be a barbell strategy with two zero-coupon bonds with the shorest and the longest maturities. This intuitively clear result has been obtained here in a rigorous way by means of the K-T conditions. In addition, we show that our result is stricly related to the problem of maximization of the unanticipated rate of return on a portfolio solving the above immunization problem (Theorem 2). Two more results concerning the unanticipated return after K years are provided with proofs. An example illustrating the role of convexity in maximization of the unanticipated return is included. Despite the fact that there exists a pretty vast literature on bond portfolio strategies, the present paper offers a new methodological approach to this area (see Ingersoll, Skelton, Weil, 1978).