Low-dose Ad26.COV2.S protection against SARS-CoV-2 challenge in rhesus macaques

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Plasma proteins and immunoglobulins in penguins (Pygoscelis adeliae).

Total and fractionated proteins were evaluated in the serum of normal penguins. Four proteins with antibody activity, determined by passive haemagglutination, were isolated by Sephadex G-200 filtration and DEAE-cellulose chromatography, from the serum of penguins (Pygoscelis adeliae) inoculated with dinitrophenylated human gamma-globulin. Immunoelectrophoresis and immunodiffusion showed that all these proteins exhibited both their own and shared antigenic determinants. On account of their electrophoretic mobility, elution conditions and characteristics of the precipitation arcs, they have been tentatively denominated IgG2 (gamma2), IgG1 (gamma1), IgM (gammam) and IgX (probably IgA).     

How to deal with ground truthing affected by human‐induced habitat change?: Identifying high‐quality habitats for the Critically Endangered Red Siskin

Species distribution models (SDM) can be valuable for identifying key habitats for conservation management of threatened taxa, but anthropogenic habitat change can undermine SDM accuracy. We used data for the Red Siskin (Spinus cucullatus), a critically endangered bird and ground truthing to examine anthropogenic habitat change as a source of SDM inaccuracy. We aimed to estimate: (1) the Red Siskin's historic distribution in Venezuela; (2) the portion of this historic distribution lost to vegetation degradation; and (3) the location of key habitats or areas with both, a high probability of historic occurrence and a low probability of vegetation degradation. We ground‐truthed 191 locations and used expert opinion as well as landscape characteristics to classify species' habitat suitability as excellent, good, acceptable, or poor. We fit a Random Forest model (RF) and Enhanced Vegetation Index (EVI) time series to evaluate the accuracy and precision of the expert categorization of habitat suitability. We estimated the probability of historic occurrence by fitting a MaxLike model using 88 presence records (1960–2013) and data on forest cover and aridity index. Of the entire study area, 23% (20,696 km²) had a historic probability of Red Siskin occurrence over 0.743. Furthermore, 85% of ground‐truthed locations had substantial reductions in mean EVI, resulting in key habitats totaling just 976 km², in small blocks in the western and central regions. Decline in Area of Occupancy over 15 years was between 40% and 95%, corresponding to an extinction risk category between Vulnerable and Critically Endangered. Relating key habitats with other landscape features revealed significant risks and opportunities for proposed conservation interventions, including the fact that ongoing vegetation degradation could limit the establishment of reintroduced populations in eastern areas, while the conservation of remaining key habitats on private lands could be improved with biodiversity‐friendly agri‐ and silviculture programs.     

Pollen sporopollenin: degradation and structural elucidation

We report the isolation of purified sporopollenin from pollen grains of different species and its complete solubilization. Exine from Pinus pinaster, Betula alba, Ambrosia elatior and Capsicum annuum was extracted by treatment with hydrogen fluoride in pyridine. These exines were purified from their aromatic moieties and from fatty acids linked by ester bonds using acidolysis and saponification treatments. The biopolymer obtained retains almost completely the shape of the original pollen grain. Fourier-transform infrared spectroscopy analysis of the isolated sporopollenin showed the absence of polysaccharide and phenolic material and the presence of carboxylic acid groups joined to unsaturations and ether linkages. Sporopollenin samples were successfully degraded by exhaustive 24-h ozonolysis at room temperature. Gentle ozonolysis (3 h at 0°C) did not completely degrade the biopolymer. The compounds obtained after exhaustive ozonolysis were analysed by gas chromatography-mass spectrometry. Dicarboxylic acids with a low number of carbon atoms were identified as major components of sporopollenin from P. pinaster, A. elatior and C. annuum, representing 28.8%, 63.2% and 88.5%, respectively, of the total compounds obtained. Fatty acids and n-alkanes also were identified in P. pinaster, A. elatior and B. alba sporopollenin. From the data obtained, an hypothesis about the chemical nature and structural arrangement of the sporopollenin is proposed. Received: 8 November 1998 / Revision accepted: 14 April 1999     

A convenient protocol for extraction and purification of DNA from Fragaria

Summary In this paper we describe a simple and efficient DNA extraction protocol for Fragaria species, a highly recalcitrant genus due to the large amount of polyphenols and polymeric carbohydrates present in strawberry tissues. The protocol yields a high quality DNA that can be amplified by polymerase chain reaction and digested with restriction endonucleases.     

Investigation and documentation of hybridization betweenParkinsonia aculeata andCercidium praecox (Leguminosae:Caesalpinioideae)

Morphometric, cytogenetic, geographical and ecological evidence for hybridization betweenParkinsonia aculeata andCercidium praecox is presented. Morphometric investigation using the character count procedure and cytogenetic observations confirm hybrid status. All diagnostic morphometric characters were intermediate in the hybrid. Both parents (2n = 28) show regular tetrad formation and pollen fertility greater than 94%. Hybrids have a chromosome number of 2n = 28 or 2n = 30, and display meiotic abnormalities including lagging chromosomes and micronucleus formation; less than 21% of hybrid pollen was fertile. Ecological and geographical information suggests that hybridization is occurring at increasing frequency due to the expanding range ofP. aculeata associated with cultivation as an ornamental, coupled with ecological disturbance and weediness, and the cultivation ofC. praecox and hybrids as fodder, ornamental and shade trees. Hybrid fertility and phenological observations, in conjunction with F-weighted principal component analysis, suggest that the progeny of F₁ hybrids are established. The hybrid is formally described asP. ×carterae.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of avocado (<Emphasis Type="Italic">Persea americana</Emphasis> Mill.) somatic embryos with fluorescent marker genes and optimization of transgenic plant recovery

Avocado globular somatic embryos were transformed with three binary vectors, pK7FNF2, pK7RNR2 and pK7S*NF2, harboring the marker genes gfp, DsRed and a gfp-gus fusion gene, respectively. GFP and DsRed fluorescence was detected in embryogenic lines growing in selection medium 2 months after Agrobacterium inoculation. The fluorescence signal was maintained thereafter in transgenic calli, as well as in mature somatic embryos. Red fluorescence in pK7RNR2 transgenic lines was higher and more easily observable than GFP fluorescence. Furthermore, calli transformed with pK7S*NF2, harboring gfp-gus, showed higher level of fluorescence than those transformed with pK7FNF2, containing two gfp. To improve plant recovery, maturated transgenic embryos that failed to germinate or showed an underdeveloped shoot were cultured for 4 weeks in a medium with 1 mg l^?1 TDZ and 1 mg l^?1 BA after partial removal of cotyledons. A 50% of embryos developed one or several shoots on the cut surface. These embryos were cultured for 4 additional weeks in a medium with 1 mg l^?1 BA for shoot elongation and then, shoots were grafted in vitro onto seedling rootstocks. Culture of micrografts in solid MS medium supplemented with 1 mg l^?1 BA allowed a 60–80% success rate. Young leaves from transgenic plants showed GFP or DsRed fluorescence located in the nucleus. The results obtained indicate that fluorescent marker genes, especially DsRed, could be useful for early selection of transgenic material and optimization of the transformation parameters in avocado. Furthermore, the protocol established allowed the successful recovery of transgenic plants, one of the main limiting steps in avocado transformation.     

The impact of cortisol in steatotic and non‐steatotic liver surgery

The intent of this study was to examine the effects of regulating cortisol levels on damage and regeneration in livers with and without steatosis subjected to partial hepatectomy under ischaemia–reperfusion. Ultimately, we found that lean animals undergoing liver resection displayed no changes in cortisol, whereas cortisol levels in plasma, liver and adipose tissue were elevated in obese animals undergoing such surgery. Such elevations were attributed to enzymatic upregulation, ensuring cortisol production, and downregulation of enzymes controlling cortisol clearance. In the absence of steatosis, exogenous cortisol administration boosted circulating cortisol, while inducing clearance of hepatic cortisol, thus maintaining low cortisol levels and preventing related hepatocellular harm. In the presence of steatosis, cortisol administration was marked by a substantial rise in intrahepatic availability, thereby exacerbating tissue damage and regenerative failure. The injurious effects of cortisol were linked to high hepatic acethylcholine levels. Upon administering an α7 nicotinic acethylcholine receptor antagonist, no changes in terms of tissue damage or regenerative lapse were apparent in steatotic livers. However, exposure to an M3 muscarinic acetylcholine receptor antagonist protected livers against damage, enhancing parenchymal regeneration and survival rate. These outcomes for the first time provide new mechanistic insight into surgically altered steatotic livers, underscoring the compelling therapeutic potential of cortisol–acetylcholine–M3 muscarinic receptors.