Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Uptake and effects of several cationic dyes on yeast (1979)
    Springer
    The journal of membrane biology 47 (1979), S. 261-284 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Several cationic dyes were found to behave as inhibitors of K+ uptake in yeast. When added at high concentrations or in a K+-free medium, dyes can also produce and efflux of K+. The dyes are taken up by the cells in a process that, in different degrees, for several cations requires glucose and is inhibited to a higher degree by K+ than by Na+. The inhibition of cation uptake is of the competitive type with EB and close to this type with other dyes. Ca2+ inhibits the uptake and effects of dyes and in some cases also seems to change the inhibition kinetics on Rb+ uptake closer to a pure competitive type. According to preliminary experiments, the efflux of K+ seems to be of the electrogenic type, and not due to the disruption of the cells. The data indicate that, independently of the existence of other types of interaction (which do exist), dyes seem to interact with the system for monovalent cation uptake of yeast in different degrees of specificity and energy requirement. This interaction can be followed by fluorescence or metachromatic changes or reduction of the dyes as observed in the dual wavelength spectrophotometer and can be inhibited specifically by K+, but not by Na+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869081
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Seasonal and geographical variation of organochlorine residues in birds from Northwest Mexico (1991)
    Springer
    Archives of environmental contamination and toxicology 21 (1991), S. 541-548 
    Details
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Eight species of birds (129 individuals) were collected from three agricultural areas with long histories of pesticide use in northwestern Mexico. Plucked carcasses were analyzed for organochlorine (OC) pesticides and polychlorobiphenyls (PCBs). DDE was found in all of the samples and at higher levels than other OCs. Mean (geometric) DDE concentrations varied from 0.04 (μg/g) ppm in mourning doves (Zenaida macroura) to 5.05 ppm in double-crested cormorants (Phalacrocorax auritus). Hexachlorocyclohexane (HCH) was detected in 95% of the samples, but at lower levels than DDE. Hexachlorobenzene (HCB) residues were detected more frequently in birds from Mexicali (62%, p 〈 0.05) than in those from Yaqui and Culiacan. HCH and HCB concentrations were significantly higher in birds from Mexicali during the winter than in the summer (p 〈 0.05), indicating accumulation of these compounds during that period. Other OCs such as DDT, DDD, dieldrin, oxychlordane, heptachlor epoxide, endosulfan, and endrin were found at lower levels and less frequently. PCBs (quantitated as Aroclor® 1260) were found mostly in cattle egrets (Bubulcus ibis) and cormorants at the three locations. Overall, concentrations of OCs were higher for Mexicali than for Yaqui and Culiacan (p 〈 0.01). In a few cases, DDE levels were above those that might adversely affect birds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01183876
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Organochlorine residues in bat guano from nine Mexican caves, 1991 (1995)
    Springer
    Ecotoxicology 4 (1995), S. 258-265 
    Details
    ISSN: 1573-3017
    Keywords: bat guano ; DDE ; pesticide residues ; Mexican caves ; Mexican free-tailed bat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering residues from use of DDT years ago in the Ojuela area of perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p′-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbamate insecticides now in extensive use are unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00116344
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...