10 research outputs found
Die Normalfarben-Skala
„Die Normalfarbenskala“ wurde als Vortrag durch Dr. A. Eibner in der Adolf Wilhelm
Keim-Gesellschaft vorgestellt, 1915 durch den Verlag der Technischen Mitteilungen
für Malerei veröffentlicht.
Nachdem im letzten Drittel des 18. Jahrhunderts eine Qualitätsverschlechterung der
Malerfarben einsetzte, nicht zuletzt durch die Entdeckung der Teerfarben, entwickelte
A. W. Keim 1886 eine Liste von Malerfarbstoffen für Wand- und Ölmalerei unter dem
Gesichtspunkt der Haltbarkeit und Beständigkeit in künstlerischer Anwendung. Diese
Liste war zum Zeitpunkt der Veröffentlichung des Vortrags die „Normalfarbenskala
der Deutschen Gesellschaft für rationelle Malverfahren“.
Dr. Alexander Eibner beschreibt in seinem Vortrag die Bedeutung dieser
Normalfarbenskala, erklärt ihre Vorzüge und übt Kritik an der Vorstellung der
Farbmittel in dieser Liste. Er fordert naturwissenschaftliche Untersuchungen und eine
dadurch begründete Revision der Normalfarbenliste
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Mammalian deltavirus without hepadnavirus coinfection in the neotropical rodent Proechimys semispinosus.
Hepatitis delta virus (HDV) is a human hepatitis-causing RNA virus, unrelated to any other taxonomic group of RNA viruses. Its occurrence as a satellite virus of hepatitis B virus (HBV) is a singular case in animal virology for which no consensus evolutionary explanation exists. Here we present a mammalian deltavirus that does not occur in humans, identified in the neotropical rodent species Proechimys semispinosus The rodent deltavirus is highly distinct, showing a common ancestor with a recently described deltavirus in snakes. Reverse genetics based on a tandem minus-strand complementary DNA genome copy under the control of a cytomegalovirus (CMV) promoter confirms autonomous genome replication in transfected cells, with initiation of replication from the upstream genome copy. In contrast to HDV, a large delta antigen is not expressed and the farnesylation motif critical for HBV interaction is absent from a genome region that might correspond to a hypothetical rodent large delta antigen. Correspondingly, there is no evidence for coinfection with an HBV-related hepadnavirus based on virus detection and serology in any deltavirus-positive animal. No other coinfecting viruses were detected by RNA sequencing studies of 120 wild-caught animals that could serve as a potential helper virus. The presence of virus in blood and pronounced detection in reproductively active males suggest horizontal transmission linked to competitive behavior. Our study establishes a nonhuman, mammalian deltavirus that occurs as a horizontally transmitted infection, is potentially cleared by immune response, is not focused in the liver, and possibly does not require helper virus coinfection
Wildlife gut microbiomes of sympatric generalist species respond differently to anthropogenic landscape disturbances
Abstract Background Human encroachment into nature and the accompanying environmental changes are a big concern for wildlife biodiversity and health. While changes on the macroecological scale, i.e. species community and abundance pattern, are well documented, impacts on the microecological scale, such as the host’s microbial community, remain understudied. Particularly, it is unclear if impacts of anthropogenic landscape modification on wildlife gut microbiomes are species-specific. Of special interest are sympatric, generalist species, assumed to be more resilient to environmental changes and which often are well-known pathogen reservoirs and drivers of spill-over events. Here, we analyzed the gut microbiome of three such sympatric, generalist species, one rodent (Proechimys semispinosus) and two marsupials (Didelphis marsupialis and Philander opossum), captured in 28 study sites in four different landscapes in Panama characterized by different degrees of anthropogenic disturbance. Results Our results show species-specific gut microbial responses to the same landscape disturbances. The gut microbiome of P. semispinosus was less diverse and more heterogeneous in landscapes with close contact with humans, where it contained bacterial taxa associated with humans, their domesticated animals, and potential pathogens. The gut microbiome of D. marsupialis showed similar patterns, but only in the most disturbed landscape. P. opossum, in contrast, showed little gut microbial changes, however, this species’ absence in the most fragmented landscapes indicates its sensitivity to long-term isolation. Conclusion These results demonstrate that wildlife gut microbiomes even in generalist species with a large ecological plasticity are impacted by human encroachment into nature, but differ in resilience which can have critical implications on conservation efforts and One Health strategies
Wildlife gut microbiomes of sympatric generalist species respond differently to anthropogenic landscape disturbances
Background Human encroachment into nature and the accompanying environmental changes are a big concern
for wildlife biodiversity and health. While changes on the macroecological scale, i.e. species community and abundance
pattern, are well documented, impacts on the microecological scale, such as the host’s microbial community,
remain understudied. Particularly, it is unclear if impacts of anthropogenic landscape modification on wildlife gut
microbiomes are species-specific. Of special interest are sympatric, generalist species, assumed to be more resilient
to environmental changes and which often are well-known pathogen reservoirs and drivers of spill-over events. Here,
we analyzed the gut microbiome of three such sympatric, generalist species, one rodent (Proechimys semispinosus)
and two marsupials (Didelphis marsupialis and Philander opossum), captured in 28 study sites in four different landscapes
in Panama characterized by different degrees of anthropogenic disturbance.
Results Our results show species-specific gut microbial responses to the same landscape disturbances. The gut
microbiome of P. semispinosus was less diverse and more heterogeneous in landscapes with close contact with
humans, where it contained bacterial taxa associated with humans, their domesticated animals, and potential
pathogens. The gut microbiome of D. marsupialis showed similar patterns, but only in the most disturbed landscape.
P. opossum, in contrast, showed little gut microbial changes, however, this species’ absence in the most fragmented
landscapes indicates its sensitivity to long-term isolation.
Conclusion These results demonstrate that wildlife gut microbiomes even in generalist species with a large ecological
plasticity are impacted by human encroachment into nature, but differ in resilience which can have critical
implications on conservation efforts and One Health strategies
Immunogenetic-pathogen networks shrink in Tome’s spiny rat, a generalist rodent inhabiting disturbed landscapes
Abstract Anthropogenic disturbance may increase the emergence of zoonoses. Especially generalists that cope with disturbance and live in close contact with humans and livestock may become reservoirs of zoonotic pathogens. Yet, whether anthropogenic disturbance modifies host-pathogen co-evolutionary relationships in generalists is unknown. We assessed pathogen diversity, neutral genome-wide diversity (SNPs) and adaptive MHC class II diversity in a rodent generalist inhabiting three lowland rainforest landscapes with varying anthropogenic disturbance, and determined which MHC alleles co-occurred more frequently with 13 gastrointestinal nematodes, blood trypanosomes, and four viruses. Pathogen-specific selection pressures varied between landscapes. Genome-wide diversity declined with the degree of disturbance, while MHC diversity was only reduced in the most disturbed landscape. Furthermore, pristine forest landscapes had more functional important MHC–pathogen associations when compared to disturbed forests. We show co-evolutionary links between host and pathogens impoverished in human-disturbed landscapes. This underscores that parasite-mediated selection might change even in generalist species following human disturbance which in turn may facilitate host switching and the emergence of zoonoses
The Development of a Standardized Neighborhood Deprivation Index
Census data are widely used for assessing neighborhood socioeconomic context. Research using census data has been inconsistent in variable choice and usually limited to single geographic areas. This paper seeks to a) outline a process for developing a neighborhood deprivation index using principal components analysis and b) demonstrate an example of its utility for identifying contextual variables that are associated with perinatal health outcomes across diverse geographic areas. Year 2000 U.S. Census and vital records birth data (1998–2001) were merged at the census tract level for 19 cities (located in three states) and five suburban counties (located in three states), which were used to create eight study areas within four states. Census variables representing five socio-demographic domains previously associated with health outcomes, including income/poverty, education, employment, housing, and occupation, were empirically summarized using principal components analysis. The resulting first principal component, hereafter referred to as neighborhood deprivation, accounted for 51 to 73% of the total variability across eight study areas. Component loadings were consistent both within and across study areas (0.2–0.4), suggesting that each variable contributes approximately equally to “deprivation” across diverse geographies. The deprivation index was associated with the unadjusted prevalence of preterm birth and low birth weight for white non-Hispanic and to a lesser extent for black non-Hispanic women across the eight sites. The high correlations between census variables, the inherent multidimensionality of constructs like neighborhood deprivation, and the observed associations with birth outcomes suggest the utility of using a deprivation, index for research into neighborhood effects on adverse birth outcomes