Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Cykliczność wielkich wymierań — komputerowe modelowanie ewolucji ekosystemu

100%

Lipowski A. , Lipowskia D.

Kosmos

2006

tom 55

nr 4

347-353

Twenty years ago, after analysing palaeontological data, raup and sepkoski suggested that mass extinctions on earth appear cyclically with a period of approximately 26 million years (my). to explain the 26my period, a number of proposals have been made involving, e.g., astronomical effects, increased volcanic activity, or the earth’s magnetic ﬁeld reversal, none of which, however, has been conﬁrmed. here we describe computer simulations of a spatially extended discrete model of an ecosystem and show that the periodicity of mass extinctions might be a natural feature of the ecosystem’s dynamics and not the result of periodic external perturbations. in our model, periodic changes of the diversity of an ecosystem and some of its other characteristics are induced by the coevolution of species. in agreement with some palaeontological data, our results show that the longevity of a species depends on the evolutionary stage at which the species was created. possible further tests of our model are also discussed.

Endovascular coil embolization of the left internal carotid artery aneurysm – case report

80%

Lipowski A. , Aboul-Hassan S. , Krasiński Z. , Woronowicz K.

Polish Journal of Surgery

2021

tom 93

nr 5

1-5

In the current case report we present a novel case of a successful coil embolization of the left internal carotid artery aneurysm. The patient presented with neck pain and a palpable pulsating tumor and was admitted to the vascular surgery clinic where an angio-CT scan of the neck was performed. Angio-CT revealed a left internal carotid artery aneurysm with a narrow neck. The patient was admitted to the department of vascular surgery where she was enrolled into endovascular coil embolization. After the procedure, control angiography showed complete embolization of the aneurysm. Three months following the procedure, doppler ultrasonography of the carotid arteries showed no demonstrable flow into the aneurysm. Six months following the procedure, angio-CT confirmed complete aneurysm thrombosis. Based on this case, endovascular coil embolization of the carotid artery aneurysms is a safe and effective method of treatment.