14 research outputs found
Stability analysis of dynamic charge in levitational melting processes
Artykuł porusza aspekty indukcyjnego topnienia lewitacyjnego metali i stopów w warunkach wysokiej czystości.
Autorzy wskazują na zagadnienia zapewnienia stabilności dynamicznej wsadu wewnątrz wzbudnika w obecności
zakłóceń sieci oraz na etapie załadunku wsadu. Podjęte rozważania są niezwykle istotne w procesie projektowania
konstrukcji wzbudnika, by zapewnić wystarczający zapas stabilności dynamicznej w praktycznym wykorzystaniu
tegoż wzbudnika.The article introduces analysis of the dynamic stability of charge in levitational melting regarding many kinds of disturbance during process. The mathematical model of the dynamics was introduced, numeric computational algorithm enabling the mathematical analysis of movement of the charge inside inductor was passe
Chlorophyll Content of Aphid-Infested Seedling Leaves of Fifteen Maize Genotypes
We measured the total chlorophyll (Chl a+b) content in seedling leaves of fifteen maize cultivars infested by two studied aphid species (oligophagous Rhopalosiphum padi L., monophagous Sitobion avenae F.) 7 and 14 days after the beginning of infestation, using a SPAD-502 chlorophyll meter. Chlorophyll loss was more severe in R. padi-infested than in S. avenae-infested plants. Chlorophyll depletion was greater after long-term (14 days) than after short-term aphid infestation in the investigated host systems. Seedlings of Złota Karłowa and Tasty Sweet were more damaged by aphid feeding; Ambrozja and Płomyk plants were less damaged by aphid feeding
Effect of phenolics from woody plants on activity of grain aphid oxidases
Changes in activity of the grain aphid peroxidase (Px) and polyphenol
oxidase (PPO) towards phenolics isolated from leaves of black currant, sour
cherry and walnut were examined. Slight increase in activity of peroxidase was
found within insect tissues after 24 h of walnut extract treatment, whereas black
currant and sour cherry strongly inhibited activity of this enzyme. Later on, the
walnut extract reduced activity of the enzyme, finally about 30%. The other
extracts showed slight changes in Px activity. The grain aphid’s polyphenol
oxidase was stimulated during the first 24 h of the experiment. Further treatment
with the phenolics extracts reduced activity of the grain aphid polyphenol oxidase.
Generally, phenolics isolated from the black currant and sour cherry were more
effective in reducing activity of the aphid peroxidase, whereas phenolics from
walnut reduced the polyphenol oxidase activity. Possible application of the
phenolics isolated from the woody plants as modern biopesticides towards the
grain aphid is discussed
Molecular screening for Bartonella henselae and Borrelia burgdorferi sensu lato co-existence within Ixodes ricinus populations in central and eastern parts of Poland
The presented study aimed at establishing the prevalence and co-infection rates of Bartonella henselae and Borrelia burgdorferi
sensu lato in Ixodes ricinus ticks collected from the central and eastern parts of Poland. The common tick individuals were
gathered in the years 2008-2009. Questing ticks were sampled by dragging a white woollen flag over lower vegetation at 17
localities within diverse types of habitats: urban recreational green areas (city parks and squares), suburban forests and rural
woodlands throughout the investigated regions of Poland. Detection of B. henselae in tested tick specimens was based on
PCR amplification of the citrate synthase (gltA) gene, while screening for the presence of B. burgdorferi s.l. DNA was carried
out by analyzing fragments of two genes: the flagellin (fla) and outer surface protein A (ospA). A total number of 1,571 I. ricinus
ticks were sampled: 865 (55.1%) nymphs, 377 females (24.0%) and 329 males (20.9%). The application of PCR assays revealed
that 76 (4.8%) tick samples were B. henselae-positive, B. burgdorferi s.l. DNA was detected in 194 specimens (12.3%), whereas
the co-existence of these pathogens was evidenced in 22 tested ticks (1.4%). Furthermore, the occurrence of bartonellae
and co-circulation of analysed microorganisms in I. ricinus was affirmed only within adult individuals, while presence of the
screened spirochetes was ascertained in both nymphal and adult ticks. It should be stressed that the suburban woods of
Warsaw and rural forests in Warsaw County characterized the highest prevalence levels of dual infection with investigated
tick-borne pathogens, whereas the lowest co-infection rates were recorded in tick populations inhabiting rural forests in
Płock County and forested areas in Korczew-Mogielnica (within the Nadbużański Landscape Park)
Molecular evidence of Anaplasma phagocytophilum and Babesia microti co-infections in Ixodes ricinus ticks in central-eastern region of Poland
The aim of the study was to elucidate the distribution of Anaplasma phagocytophilum and Babesia microti co-infection in Ixodes
ricinus populations within the central-eastern region of Poland. The prevalence of analysed tick-borne human pathogens in
single and polymicrobial infections in I. ricinus ticks were analysed using the conventional and nested PCR techniques. A total
number of 1,123 questing tick individuals (291 females, 267 males and 565 nymphs) were collected at different ecosystems
(municipal parks, suburban forests, and woodlands). In the presented study, 95 samples of ticks (8.5%) were infected with
A. phagocytophilum, 3.1% (n=35) with B. microti, whereas the co-existence status of these human pathogens was detected
in 1.8% (n=20) of all tested samples. It has been demonstrated that the prevalence of co-infection status was the highest
among females of I. ricinus (11 samples, 3.8%), whereas the lowest within tested nymphs (5 samples, 0.9%). Ticks collected
at city parks in Warsaw and suburban areas of this town characterized the highest prevalence of co-infections (3.3 and
4.8%, respectively). Furthermore, it was established that co-infection rates of ticks inhabiting woodlands within Kampinos
National Park and Nadbużański Landscape Park were similar and reached the levels of 1.4% (n=5) and 1.1% (n=4), respectively