1,700 research outputs found
Ökologisches Verantwortungsbewusstsein und Ansatzpunkte zur Förderung im Unternehmen
In diesem Beitrag wird eine Konzeption zum ökologischen Verantwortungsbewusstsein vorgestellt, die sich auf folgende Teilbereiche bezieht: (a) auf das ökologische Denken bzw. Strukturwissen zu Umweltproblemen; (b) auf ökologische Kontrollvorstellungen zu Handlungsmöglichkeiten angesichts dieser Probleme sowie (c) auf ökologische Moral- bzw. Wertvorstellungen. Zuerst geht es um die theoretischen und empirischen Zusammenhänge zwischen diesen Teilbereichen. Außerdem wird auf Bezüge zum tatsächlichen Umwelthandeln eingegangen. Anschließend werden Konsequenzen für die Förderung des ökologischen Verantwortungsbewusstseins und des Umwelthandelns im Unternehmen aufgezeigt. Diese zielen vor allem auf den Bereich der Umweltbildung, auf die Integration individuellen Umwelthandelns in kollektive Handlungsstrategien und auf die Entwicklung einer ökologischen Konfliktkultur im Unternehmen.The conception of the awareness of ecological responsibility presented in this paper comprises three subareas: (a) knowledge of structural aspects of ecological problems, (b) ecological control attributions, and (c) ecological moral judgments. First, theoretical and empirical connections between the subareas are discussed, as are their effects on actual ecological behavior. Second, consequences for the advancement of ecological responsibility and behavior in organizations will be shown. These primarily concern the areas of environmental education, the integration of individual ecological behavior into collective strategies, and the development of a corporate environmental "conflict culture"
Extended-Spectrum Beta-Lactamases Producing E. coli in Wildlife, yet Another Form of Environmental Pollution?
Wildlife is normally not exposed to clinically used antimicrobial agents but can acquire antimicrobial resistant bacteria through contact with humans, domesticated animals and the environment, where water polluted with feces seems to be the most important vector. Escherichia coli, an ubiquitous commensal bacterial species colonizing the intestinal tract of mammals and birds, is also found in the environment. Extended-spectrum beta-lactamases producing E. coli (ESBL-E. coli) represent a major problem in human and veterinary medicine, particular in nosocomial infections. Additionally an onset of community-acquired ESBL-E. coli infections and an emergence in livestock farming has been observed in recent years, suggesting a successful transmission as well as persistence of ESBL-E. coli strains outside clinical settings. Another parallel worldwide phenomenon is the spread of ESBL-E. coli into the environment beyond human and domesticated animal populations, and this seems to be directly influenced by antibiotic practice. This might be a collateral consequence of the community-onset of ESBL-E. coli infections but can result (a) in a subsequent colonization of wild animal populations which can turn into an infectious source or even a reservoir of ESBL-E. coli, (b) in a contribution of wildlife to the spread and transmission of ESBL-E. coli into fragile environmental niches, (c) in new putative infection cycles between wildlife, domesticated animals and humans, and (d) in problems in the medical treatment of wildlife. This review aims to summarize the current knowledge on ESBL-E. coli in wildlife, in turn underlining the need for more large scale investigations, in particular sentinel studies to monitor the impact of multiresistant bacteria on wildlife
Adhesive threads of extraintestinal pathogenic Escherichia coli
The ability to adhere to host surfaces is by far the most vital step in the successful colonization by microbial pathogens. Colonization begins with the attachment of the bacterium to receptors expressed by cells forming the lining of the mucosa. Long hair like extracellular appendages called fimbriae, produced by most Gram-negative pathogens, mediate specific attachment to the epithelial cell surface. Associated with the fimbriae is a protein called an adhesin, which directs high-affinity binding to specific cell surface components. In the last couple of years, an enormous amount of research has been undertaken that deals with understanding how bacterial pathogens adhere to host cells. E. coli in all probability is one of the best studied free-living organisms. A group of E. coli called Extraintestinal pathogenic E. coli (ExPEC) including both human and animal pathogens like Uropathogenic E. coli (UPEC), Newborn meningitic E. coli (NMEC) and Avian pathogenic E. coli (APEC), have been found to harbour many fimbriae including Type 1 fimbriae, P fimbriae, curli fibres, S fimbriae, F1C fimbriae, Dr fimbriae, afimbrial adhesins, temperature-sensitive haemagglutinin and many novel adhesin gene clusters that have not yet been characterized. Each of these adhesins is unique due to the recognition of an adhesin-specific receptor, though as a group these adhesins share common genomic organization. A newly identified putative adhesin temporarily termed ExPEC Adhesin I, encoded by gene yqi, has been recently found to play a significant role in the pathogenesis of APEC infection, thus making it an interesting candidate for future research. The aim of this review is to describe the role of ExPEC adhesins during extraintestinal infections known till date, and to suggest the idea of investigating their potential role in the colonization of the host gut which is said to be a reservoir for ExPEC
Does Reductive Evolution Correlate with Habitat and Pathotype?
IbeA (invasion of brain endothelium), which is located on a genomic island
termed GimA, is involved in the pathogenesis of several extraintestinal
pathogenic E. coli (ExPEC) pathotypes, including newborn meningitic E. coli
(NMEC) and avian pathogenic E. coli (APEC). To unravel the phylogeny of GimA
and to investigate its island character, the putative insertion locus of GimA
was determined via Long Range PCR and DNA-DNA hybridization in 410 E. coli
isolates, including APEC, NMEC, uropathogenic (UPEC), septicemia-associated E.
coli (SEPEC), and human and animal fecal isolates as well as in 72 strains of
the E. coli reference (ECOR) collection. In addition to a complete GimA (~20.3
kb) and a locus lacking GimA we found a third pattern containing a 342 bp
remnant of GimA in this strain collection. The presence of GimA was almost
exclusively detected in strains belonging to phylogenetic group B2. In
addition, the complete GimA was significantly more frequent in APEC and NMEC
strains while the GimA remnant showed a higher association with UPEC strains.
A detailed analysis of the ibeA sequences revealed the phylogeny of this gene
to be consistent with that obtained by Multi Locus Sequence Typing of the
strains. Although common criteria for genomic islands are partially fulfilled,
GimA rather seems to be an ancestral part of phylogenetic group B2, and it
would therefore be more appropriate to term this genomic region GimA locus
instead of genomic island. The existence of two other patterns reflects a
genomic rearrangement in a reductive evolution-like manner
Movement behaviour of native and invasive small mammals shows logging may facilitate invasion in a tropical rainforest
Nanoscopic compartmentalization of membrane protein motion at the axon initial segment
The axon initial segment (AIS) is enriched in specific adaptor, cytoskeletal, and transmembrane molecules. During AIS establishment, a membrane diffusion barrier is formed between the axonal and somatodendritic domains. Recently, an axonal periodic pattern of actin, spectrin, and ankyrin forming 190-nm-spaced, ring-like structures has been discovered. However, whether this structure is related to the diffusion barrier function is unclear. Here, we performed single-particle tracking time-course experiments on hippocampal neurons during AIS development. We analyzed the mobility of lipid-anchored molecules by high-speed single-particle tracking and correlated positions of membrane molecules with the nanoscopic organization of the AIS cytoskeleton. We observe a strong reduction in mobility early in AIS development. Membrane protein motion in the AIS plasma membrane is confined to a repetitive pattern of ∼190-nm-spaced segments along the AIS axis as early as day in vitro 4, and this pattern alternates with actin rings. Mathematical modeling shows that diffusion barriers between the segments significantly reduce lateral diffusion along the axon
Resilience of Ecosystem Structure and Function during Succession Following Prescribed Burning in a Shrub‐Steppe Ecosystem in Wyoming, USA
Observation of Coulomb-Assisted Dipole-Forbidden Intraexciton Transitions in Semiconductors
We use terahertz pulses to induce resonant transitions between the
eigenstates of optically generated exciton populations in a high-quality
semiconductor quantum-well sample. Monitoring the excitonic photoluminescence,
we observe transient quenching of the exciton emission, which we attribute
to the terahertz-induced -to- excitation. Simultaneously, a pronounced
enhancement of the -exciton emission is observed, despite the -to-
transition being dipole forbidden. A microscopic many-body theory explains the
experimental observations as a Coulomb-scattering mixing of the 2 and 2
states, yielding an effective terahertz transition between the 1 and 2
populations.Comment: 5 pages, 3 figure
Pasteurella multocida Involved in Respiratory Disease of Wild Chimpanzees
Pasteurella multocida can cause a variety of diseases in various species of mammals and birds throughout the world but nothing is known about its importance for wild great apes. In this study we isolated P. multocida from wild living, habituated chimpanzees from Taï National Park, Côte d'Ivoire. Isolates originated from two chimpanzees that died during a respiratory disease outbreak in 2004 as well as from one individual that developed chronic air-sacculitis following this outbreak. Four isolates were subjected to a full phenotypic and molecular characterisation. Two different clones were identified using pulsed field gel electrophoresis. Multi Locus Sequence Typing (MLST) enabled the identification of previous unknown alleles and two new sequence types, ST68 and ST69, were assigned. Phylogenetic analysis of the superoxide dismutase (sodA) gene and concatenated sequences from seven MLST-housekeeping genes showed close clustering within known P. multocida isolated from various hosts and geographic locations. Due to the clinical relevance of the strains described here, these results make an important contribution to our knowledge of pathogens involved in lethal disease outbreaks among endangered great apes
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