Use of autonomous audio recordings for the rapid inventory of birds in the white‐sand forests of the Peruvian Amazon

White‐sand forests are patchily distributed ecosystems covering just 5% of Amazonia that host many specialist species of birds not found elsewhere, and these forests are threatened due to their small size and human exploitation of sand for construction projects. As a result, many species of birds that are white‐sand specialists are at risk of extinction, and immediate conservation action is paramount for their survival. Our objective was to evaluate current survey methods and determine the relative effect of the size of patches of these forests on the presence or absence of white‐sand specialists. Using point counts and autonomous recorders, we surveyed avian assemblages occupying patches of white‐sand forest in the Peruvian Amazon in April 2018. Overall, we detected 126 species, including 21 white‐sand forest specialists. We detected significantly more species of birds per survey point with autonomous recorders than point counts. We also found a negative relationship between avian species richness and distance from the edge of patches of white‐sand forest, but a significant, positive relationship when only counting white‐sand specialists. Although we detected more species with autonomous recorders, point counts were more effective for detecting canopy‐dwelling passerines. Therefore, we recommend that investigators conducting surveys for rare and patchily distributed species in the tropics use a mixed‐method approach that incorporates both autonomous recorders and visual observation. Finally, our results suggest that conserving large, continuous patches of white‐sand forest may increase the likelihood of survival of species of birds that are white‐sand specialists.     

Profiling SARS-CoV-2 HLA-I peptidome reveals T cell epitopes from out-of-frame ORFs

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Capillary permeability in the pancreas and colon: restriction of exogenous and endogenous molecules by fenestrated endothelia

The permeability properties of fenestrated capillaries in the colon and exocrine and endocrine pancreas to exogenous and endogenous molecules were examined. The exogenous tracers horseradish peroxidase (Einstein-Stokes radius [ESR], 3.0 nm), hemoglobin (ESR, 3.2 nm), and ferritin (ESR, 6.1 nm) were injected intravenously and allowed to circulate for 5-90 min. Tissues were removed and processed for cytochemical or standard electron microscopic examination. The endogenous plasma proteins albumin (ESR, 3.5 nm) and IgG (ESR, 5.5 nm) were localized by immunocytochemistry using the protein A-gold technique. All vessels examined were permeable to HRP in less than 5 min. In contrast, these vessels were restrictive to the slightly larger hemoglobin molecule (60-min circulation) and to ferritin (90-min circulation). Capillaries in the exocrine and endocrine pancreas were restrictive to albumin and IgG. These results demonstrate the presence of fenestrated capillary beds, in addition to the choriocapillaris, that are restrictive to molecules with ESR greater than or equal to 3.2 nm. Capillaries in the mucosa of the colon were restrictive to hemoglobin and ferritin but did not restrict albumin or IgG. This indicates that these vessels are of the permeable type. However, the rate of transendothelial movement of molecules is slower than that of other permeable vessels, such as in the ileo-jejunum. This study has provided further evidence for the existence of fenestrated endothelia that are restrictive to exogenous and/or endogenous molecules.     

Immunocytochemical characterisation of endophytic bacteriaAzospirillum brasilense, Herbaspirillum seropedicae, Burkholderia ambifaria andGluconacetobacter diazotrophicus

In the present work an immunocytochemical characterisation of four endophytic bacterial species has been made by using polyclonal antiserum produced against each of the four bacterial strains previously heated at 60 °C. The aim of this researchsito identify common elements among bacteria associated with their endophytic behaviour. Analysis of extracts of each strain by immunoblotting and ELISA confirmed the presence of proteins from different bacterial strains made up of common epitopes. However, antisaproduced againstHerbaspirillum seropedicae andBurkholderia ambifaria show a high number of bands recognised on each extracts, while antisera againstAzospirillum brasilense andGluconacetobacter diazotrophicus show a low number of bands recognised on each extract. Immunogold labelling showed that epitopes are located both on the cell wall and in the cytoplasm; most likely they could be preursor cell wall proteins synthesized inside the cytoplasm and subsequently transported onto cell wall. Finally, the common bands amog bacterial strains revealed by immunoblotting could play a role as active hydrolases involved in host tissue penetration.     

Cytochemical localization of alkaline phosphatase and ouabain-sensitive K+-dependent p-nitrophenylphosphatase activities in brain capillaries of the newt

The ultrastructural localization of alkaline phosphatase and K+-NPPase was investigated in brain capillaries of newt by a cytochemical study using whole brain perfusion. The alkaline phosphatase activity was present in both luminal and antiluminal membranes of the endothelial cells. By contrast, the K+-NPPase was located only in antiluminal membranes of the brain capillaries. This distinct enzymatic distribution suggested that the luminal and antiluminal membranes are functionally different. The role of alkaline phosphatase and K+-NPPase in the blood brain barrier is discussed.     

A recombination map of the human X-chromosome

Summary A family with 11 normal boys has been typed with DNA probes spanning the whole of the X-chromosome to observe directly the recombination events in 11 meioses from one female. This has (a) identified apparent recombination hot-spots on the X-chromosome; (b) shown the positions and numbers of cross-overs that have occurred in the p and q arms; (c) not shown any cross-overs in the centromeric region and (d) enabled the calculation of the genetic length of the X-chromosome.     

Evaluation of DNA damage induced by norfloxacin in liver and kidney of adult rats and in fetal tissues after transplacental exposure

Norfloxacin, a recently developed antimicrobial fluoroquinolone, was investigated for DNA-damaging activity in rat liver and kidney. After oral administration of single doses ranging from 1 to 8 mmole/kg, DNA fragmentation was absent in liver and kidney both 2 and 6 h after treatment. However, when administered to pregnant rats, the highest doses produced a detectable amount of DNA damage in fetal tissues. This damage appears to be an aspecific consequence of maternal and fetal toxicity rather than a specific genotoxic effect.     

The Identification of Congeners and Aliens by Drosophila Larvae

We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn ^97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn ^97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles.