Wyniki wyszukiwania

1

The thyroid structure in ontogenetic development of Bufo calamita Laur.

100%

Francois-Krassowska A.

Bulletin of the Polish Academy of Sciences. Biological Sciences

|

1989

|

tom 37

|

nr 4-6

2

Qualitative properties of Melissa officinalis L. during ontogenetic development

100%

Vaverkova S., Holla M., Tekel J., Haban M., Vozar I.

Herba Polonica

|

2002

|

tom 48

|

nr 4

Qualitative properties of Melissa officinalis L. have been studied during five vegetation periods at three localities in Slovak Republic. The results are averages of the factors under investigation. The oil content in individual leaf insertions ranged in the way that the highest amount of the oil was contained in ontogenetically youngest ones. The composition of the oil in stalks and leaves depended also on the ontogenetic phase of plant development, whereas exists a close relationship among the contents of citronellal, neral and geranial.

3

Non-metric variation in red vole populations within the East-Ural Radioactive Track [EURT] zone

84%

Vasilyev A. G., Vasilyeva I. A.

Acta Theriologica. Supplement

|

1995

|

nr 03

Ecological monitoring of red vole Clethrionomys rutilus (Pallas, 1778) populations, carried out for two years (1992-1993) in the Sverdlovsk region near Kamensk-Ural'ski, revealed an increase of morphological diversity in terms of non-metric skull traits along the axis of the East-Ural Radioactive Track (EURT). In the population affected by radioactive contamination, frequencies of non-metric skull traits deviated significantly from those in two control populations located beyond the EURT boundaries. The deviations were not related to particular environmental factors varying among the years of our study, which implied a genetic basis of non-metric differentiation. We suggest that the observed increase of phenotypic malformations within the EURT zone has been caused by the permanent impact of low doses of radioactive contamination, leading to an accumulation of minor mutations and to disurbances in regular ontogenetic development of the red vole.

4

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida) during ontogenetic development

67%

Lotocka M., Styczynska-Jurewicz E.

Oceanologia

|

2001

|

tom 43

|

nr 4

The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdańsk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1) nauplii, (2) copepodids I–III and (3) copepodids IV–V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC). As ontogenetic development progressed, significant changes occurred in the proportion of particular pigments in the total pigment pool of the various developmental groups. Astaxanthin and canthaxanthin occurred in all the groups, the former being clearly dominant. However, an increasing percentage of astaxanthin esters was recorded in the copepodids I–III, and even more in the copepodids IV–V and adults group. Most probably, astaxanthin is the main pigment active in copepod lipid metabolism. Carotenoid pigments in copepods very likely act as efficient free-electron quenchers and may be involved as antioxidants in rapid lipid metabolism. The exogenously feeding stages (late nauplii and copepodids) transform plant carotenoids taken from food and are evidently capable of metabolising astaxanthin by esterification and further degradation. It is emphasised that, according to literature data, astaxanthin esters may have an even higher quenching ability. It is suggested that crustacean carotenoid pigments, with their electron donor-acceptor abilities, may replace oxygen in peroxidation processes connected with lipid metabolism. The consequences of such a physiological role of astaxanthin for present-day estimations of energy balances in zooplankton communities are mentioned.

5

Osteology of the sauropod embryos from the Upper Cretaceous of Patagonia

67%

Salgado L., Coria R. A., Chiappe L. M.

Acta Palaeontologica Polonica

|

2005

|

tom 50

|

nr 1

Exceptionally well−preserved embryonic skulls of Upper Cretaceous (Campanian Anacleto Formation) sauropods from Auca Mahuevo (Neuquén Province, Argentina) provide important insights into the ontogeny and evolution of titanosaurian neosauropods. The most important cranial modifications occurring during titanosaurian ontogeny appear to be centered on the infraorbital and narial regions, which exhibit a substantial degree of “mosaic” evolution. On one hand, the Auca Mahuevo embryos show a large jugal that forms part of the lower margin of the skull and unretracted external nares, as indicated by the position and orientation of the lacrimals as well as the anterior extension of the frontals. Both of these features are ancestral for neosauropods, being present in prosauropods. On the other hand, the embryonic skull exhibits a large ventral notch, tentatively interpreted as homologous to the neosauropod preantorbital fenestra, that opens ventral to the jugal and between the maxilla and the quadratojugal, and a temporal region that closely resembles the adult neosauropod condition. This mosaic of character states indicates that different regions of the skull of titanosaurian neosauropods acquired their characteristic morphology at substantially different rates during their ontogenetic development.

6

Effect of organic mercury exposure during early stage of ontogenic development on the central dopaminergic system in adult rats

67%

Durczok A., Szkilnik R., Brus R., Nowak P., Labus L., Konecki J., Drabek K., Kuballa G., Rycerski W., Mengel K.

Polish Journal of Environmental Studies

|

2002

|

tom 11

|

nr 4

Organic mercury (CH3HgCl) with metal concentration 5 ppm in tap water was applied to rats suckling their newborn for the first 21 days of life. A second group of young rats took the mercury in their tap water 5 ppm from the 22nd to the 43rd day of postnatal life. Control rats drank tap water only. In 2-month-old male rats the following behavioral study was performed after saline or specific central dopamine receptor agonists and agonists apply (quinpirole, SKF-38393, haloperidol, SCH-23390): irritability, yawning behavior, oral activity, locomotion, exploratory activity, and catalepsy. In the striatum and frontal cortex of three examined groups the biogenic amines levels (DA, DOPAC, HVA, 3-MT, 5-HT, 5-HIAA, NA) were estimated by means of HPLC/ED technique, and DA and 5-HT turnover. The effect of quinpirole (a central dopamine D2 receptor agonists) was also examined on (3H)glucose uptake in discrete parts of the brain. It was shown that mercury affected behavioral changes after dopaminergic agents apply to adult animals when exposed in the period from the 22nd to 43rd day of postnatal development. Biochemical changes (biogenic amines level, turnover and (3H)glucose uptake) were more pronounced in adult animals exposed to mercury via mother's milk (1st to 21st day of life). In light of the above we conclude that early postnatal exposure of rats to organic mercury modulates activity of the central dopamine neurotransmitter system.

7

Changes in biological status of the Jastarnia population over the last 20-year period

51%

Siniarska A., Lhotska L., Dickinson F.

Studies of Human Ecology

|

1992

|

tom 10

Ograniczanie wyników

The thyroid structure in ontogenetic development of Bufo calamita Laur.

Qualitative properties of Melissa officinalis L. during ontogenetic development

Non-metric variation in red vole populations within the East-Ural Radioactive Track [EURT] zone

Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida) during ontogenetic development

Osteology of the sauropod embryos from the Upper Cretaceous of Patagonia

Effect of organic mercury exposure during early stage of ontogenic development on the central dopaminergic system in adult rats

Changes in biological status of the Jastarnia population over the last 20-year period