Geometric formality of homogeneous spaces and of biquotients

We provide examples of homogeneous spaces which are neither symmetric spaces nor real cohomology spheres, yet have the property that every invariant metric is geometrically formal. We also extend the known obstructions to geometric formality to some new classes of homogeneous spaces and of biquotients, and to certain sphere bundles.Comment: 15 page

Survey of Pathogens in Poultry Litter in the United States

Poultry litter is one of many components resulting from the production of broilers. Understanding poultry litter microbiological composition is very beneficial when attempting to improve the broiler\u27s environmental conditions and searching for the best uses for this valuable industry by-product. The objective of this study was to collect samples of poultry litter throughout the United States and determine the presence of bacteria in the litter. Tests were conducted for total bacteria, Gram negative bacteria, Gram positive bacteria, Staphylococcus, Escherichia coli, and coliforms. Poultry litter samples were taken from 12 different regions throughout the United States and were analyzed in one central laboratory. Statistical analysis of the data revealed a significant difference (P\u3c.05) among regions for each category of bacteria samples, excluding E. coli. The relationship between litter bacterial load and litter pH was also examined. No significant differences were present, but in general, higher litter pH and higher bacterial load were correlated

Impacts of Poultry House Environment on Poultry Litter Bacterial Community Composition

Viral and bacterial pathogens are a significant economic concern to the US broiler industry and the ecological epicenter for poultry pathogens is the mixture of bedding material, chicken excrement and feathers that comprises the litter of a poultry house. This study used high-throughput sequencing to assess the richness and diversity of poultry litter bacterial communities, and to look for connections between these communities and the environmental characteristics of a poultry house including its history of gangrenous dermatitis (GD). Cluster analysis of 16S rRNA gene sequences revealed differences in the distribution of bacterial phylotypes between Wet and Dry litter samples and between houses. Wet litter contained greater diversity with 90% of total bacterial abundance occurring within the top 214 OTU clusters. In contrast, only 50 clusters accounted for 90% of Dry litter bacterial abundance. The sixth largest OTU cluster across all samples classified as an Arcobacter sp., an emerging human pathogen, occurring in only the Wet litter samples of a house with a modern evaporative cooling system. Ironically, the primary pathogenic clostridial and staphylococcal species associated with GD were not found in any house; however, there were thirteen 16S rRNA gene phylotypes of mostly Gram-positive phyla that were unique to GD-affected houses and primarily occurred in Wet litter samples. Overall, the poultry house environment appeared to substantially impact the composition of litter bacterial communities and may play a key role in the emergence of food-borne pathogens

«WE UNITE WITCH CULTURE»

An interview with historian, corresponding member of the Serbian Academy of Sciences and Arts, at the present time - Ambassador Extraordinary and Plenipotentiary of the Republic of Serbia in the Russian Federation Slavenko Terzic (ST). Interviewed by Doctor of Philosophy, Professor M.V. Silantieva (MS). MGIMO senior lecturer, the specialist on Serbian culture L.V Nekhay and Candidate of philosophical sciences M.A. Khalil contributed to the interview. Exclusive interview to the Journal "Concept: Philosophy, Religion, Culture"

Differential Tolerance to Increasing Heterospecific Pollen Deposition in Two Sympatric Species of Burmeistera (Campanulaceae: Lobelioideae)

Premise of research. Heterospecific pollen deposition on stigmas can impact plant reproduction by decreasing seed set or inducing fruit abortion. Pollinating bats often carry pollen from many species on their fur, and thus bat-pollinated flowers may exhibit tolerance to heterospecific pollen deposition, but to our knowledge this has never been studied. We investigated the relative impact of increasing heterospecific pollen deposition on female reproduction of two sympatric species of Burmeistera that experience pollen transfer between them by their shared bat pollinators.Methodology. We simulated heterospecific pollen deposition by applying pollen mixtures that differed in the ratio of heterospecific to conspecific flowers used to make them (3∶1; 2∶2, and 1∶3) and measured female reproduction by quantifying fruit abortion, seed number, and seed mass.Pivotal results. For Burmeistera borjensis, applying a higher relative amount of heterospecific pollen led to decreased seed production and lighter seed mass, whereas no significant effect of increasing heterospecific pollen was detected in Burmeistera ceratocarpa. Burmeistera borjensis aborted more fruits than B. ceratocarpa (44.1% vs. 18.8%); however, in both species the probability of fruit abortion was not affected by pollination treatment.Conclusions. We detected asymmetric impacts on female reproduction between this pair of sympatric Burmeistera: while increasing heterospecific pollen deposition decreased seed production and seed mass for B. borjensis, it had no detectable effect on B. ceratocarpa. Prior work shows that in nature B. borjensis receives much lower amounts of heterospecific pollen than B. ceratocarpa, and thus results suggest that B. ceratocarpa may have stronger gametic or postzygotic isolating barriers to be able to tolerate heterospecific pollen deposition. Future work should explore how different isolation mechanisms contribute to the asymmetric effects on female reproduction that we report here and whether tolerance to heterospecific pollen deposition is a common response among bat-pollinated plants and other plant taxa relying on low-fidelity pollinators