Habitat Selection in Dung Beetles (Family Scrabaeidae; Subfamily Scarabaeinae) in the Wasgomuwa National Park

A study was carried out to investigate habitat selection of dung beetles in terms of bothhabitat and dung types. The present study was considered necessary as information on theecology of dung beetles in the dry zone of Sri Lanka is lacking. A total of 125 pitfall trapswere set in five habitat types (dry-mixed evergreen forest, riverine forest, stream/river banks,scrubland and grassland) and using five types of mammalian dung (leopard, ungulate,elephant, bear and buffalo) as baits. The pitfall traps were laid in the morning and kept openfor 24 hrs. A two-way ANOVA was conducted to discern significant differences betweenspecies richness and abundance of dung beetles across habitats and dung types.A total of 455 individuals belonging to 22 species and 7 genera were recorded from the pitfalltraps. This included one endemic species. Significant differences in species richness wasapparent (P<0.05;F=3.34) between the different habitat types with the highest number ofspecies of dung beetles in the riverine habitat (20 species) and the lowest in stream/river bankhabitats (8 species). No significant differences were recorded with respect to abundanceacross the habitat types. However there was a trend that, from among the five habitats, thestream/river banks showed highest abundance whilst the scrubland had the lowest abundance.Considering preferences of dung types, significant differences were apparent for both speciesrichness (P<0.05; F=4.09) and abundance (P<0.05; F= 0.02). The highest species richnesswas supported by leopard dung (19 species) whilst the lowest number of species (11 speciesin each) was observed in both bear and ungulate dung. Highest abundance of dung beetleswas on bear dung whilst the lowest was on ungulate dung. Moreover some species wererestricted only to a few habitats or dung types (Onthophagus cervus only in riverine habitatand Onthophagus quedentatus only in buffalo dung).This study has for the first time revealed habitat and dung preferences among dung beetles inthe dry zone Sri Lanka. Such information would be essential for the maintenance of a healthypopulation of dung beetles, which in turn would benefit natural ecosystems because of theirinvaluable ecological services.

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

Does Pattern of soil resource heterogeneity determine plant community structure? An experimental investigation

1. Spatial and temporal pattern of nutrient delivery to individual plants and plant populations can affect growth and allocation of biomass to roots and shoots. We predicted that it would also affect attributes of plant community structure, including species composition, diversity, and partitioning of biomass between above- and below-ground parts. We tested these predictions experimentally by providing the same quantity of nutrients in five different patterns to sown plant communities grown under field conditions for 2 years. We used orthogonal contrasts to compare the effects on community structure of homogeneous vs. heterogeneous nutrient supply, supply of nutrients in patches at two different densities, and provision of nutrients in spatially predictable vs. unpredictable patches. We harvested above- and below-ground plant biomass, and measured species richness, diversity, and species population sizes. 2. Pattern of nutrient delivery significantly affected community biomass and below-ground : above-ground biomass partitioning. Treatments with the lowest density of nutrient-rich patches supported 44% more total biomass than homogeneous treatments, largely as a result of greater (71% more) below-ground biomass, which resulted in a 39% increase in community below-ground : above-ground biomass ratio. 3. Above-ground community composition was also affected by treatment. There were several instances in which biomass, percentage cover or population sizes of different species, were affected by treatment. There were few significant differences between communities in treatments with predictable and unpredictable nutrient patches. Treatment did not affect species richness or diversity, despite high power to detect small differences. 4. We conclude that the spatial and temporal pattern of nutrient supply strongly affects some important facets of plant community structure, but has less influence on others. Further understanding of community responses to the pattern of nutrient supply will require experiments testing the responses of individual species to heterogeneity with and without competitors present

The effects of spatial pattern of nutrient supply on yield, structure and mortality in plant populations

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