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:

Differences in bat activity in relation to bat detector height: implications for bat surveys at proposed windfarm sites

100%

Collins J. , Jones G.

nr 2

We recorded bat activity simultaneously at ground level and 30 m height using Anabat II bat detectors and Anabat ZCAIM recording units mounted on masts at seven sites of varying habitat type in eastern England. At the lower detectors 6194 passes were recorded; 90.02% of calls were from Pipistrellus; 6.91 % were from Nyctalus/Eptesicus; 1.70% were Myotis/Plecotus; 0.13% were Barbastella and 1.24% could not be determined to species. At the higher detectors 484 passes were recorded from Pipistrellus (65.08%) and Nyctalus/Eptesicus (34.09%) and 0.83% were not determined to species. Total bat passes and the number of Pipistrellus passes were significantly higher on the lower detectors compared with the upper detectors. The difference between numbers of passes of Nyctalus/Eptesicus at the upper and lower detectors was not significant, despite proportionally more passes of these species being recorded at height. No extra species groups were recorded at height than were recorded at ground level except at one site where closed canopy broadleaved woodland surrounded the mast. Here, Nyctalus/Eptesicus species were recorded only at height. Overall, 28% of Nyctalus/Eptesicus passes and 5% of Pipistrellus passes were recorded exclusively at height, and not at ground level. Assessing bat activity levels from ground level detectors only can therefore be misleading, particularly when surveying high-flying species that are most likely to be at risk from wind turbine developments.

Peroxidation of proteins and lipids in suspensions of liposomes, in blood serum, and in mouse myeloma cells

80%

Gebicki J. M. , Du J. , Collins J. , Tweeddale H.

nr 4

There is growing evidence that proteins are early targets of reactive oxygen species, and that the altered proteins can in turn damage other biomolecules. In this study, we measured the effects of proteins on the oxidation of liposome phospholipid membranes, and the formation of protein hydroperoxides in serum and in cultured cells exposed to radiation-generated hydroxyl free radicals. Lysozyme, which did not affect liposome stability, gave 50% protection when present at 0.3 mg/ml, and virtually completely prevented lipid oxidation at 10 mg/ml. When human blood serum was irradiated, lipids were oxidized only after the destruction of ascorbate. In contrast, peroxidation of proteins proceeded immediately. Protein hydroperoxides were also generated without a lag period in hybrid mouse myeloma cells, while at the same time no lipid peroxides formed. These results are consistent with the theory that, under physiological conditions, lipid membranes are likely to be effectively protected from randomly-generated hydroxyl radicals by proteins, and that protein peroxyl radicals and hydroperoxides may constitute an important hazard to biological systems under oxidative stress.