The coronavirus disease 2019 (COVID-19) pandemic has upended almost every facet of academia (1). Almost overnight the system faced a sudden transition to remote teaching and learning, changes in grading systems, and the loss of access to research resources. Additionally, shifts in household labor, childcare, Many women academics will likely bear a greater burden during the coronavirus disease 2019 (COVID-19) pandemic. Academia needs to enact solutions to retain and promote women faculty who already face disparities regarding merit, tenure, and promotion. Image credit: Dave Cutler (artist).
In response to COVID-19, in spring, 2020 many of us rapidly took our in-person courses to an online format. This was panic pedagogy and we made the best of an emergency situation. Going forward, we now have a chance to reflect and think critically about how to best develop and deliver evolutionary and ecological content online. In this piece we challenge instructors to use the opportunity created by the COVID-19 pandemic to rethink the way in which they teach. Let us leverage the situation to increase use of active and inclusive practices in our (online) classrooms. We encourage instructors to be
The growth and development of fifteen species of Acridoidea were studied, with and without the addition of tannic acid in concentrations of up to 20% dry weight. In no case was digestion disturbed, and only at the high levels was there a significant reduction in consumption. Polyphagous species showed no deleterious effects, and in two species tannin was beneficial, while graminivorous acridids showed reduced growth rates and poor survival. The difference lies mainly in the fact that tannic acid penetrates the peritrophic membrane in the graminivorous species, and causes damage to the midgut epithelium with the eventual development of lesions and the occurrence of tannin in the haemocoel. ZUSAMMENFASSUNG UNTERSCHIEDLICHE WIRKUNGEN AUFGENOMMENER TANNINSAEURE AUF ACRIDOIDEA‐ARTEN Wachstum und Entwicklung von 15 Acridoidea‐Arten wurde studiert und zwar mit und ohne Zugabe von Tanninsäure zur Nahrung in Konzentrationen bis zu 20% Trockensubstanz. In keinem Fall wurde die Verdauung beeinträchtigt; nur in den hohen Konzentrationen wurde die Futteraufnahme gesichert vermindert. Polyphage Arten zeigten keine ungünstige Effekte, und bei zwei Arten wirkte Tannin günstig. Dagegen wurde bei grasfressenden Heuschrecken das Wachstum reduziert, und die Überlebensrate war gering. Der Unterschied liegt im wesentlichen darin, dass bei grassfressenden Arten Tanninsäure in die peritrophische Membran eindringt und das Mitteldarmephithel beschädigt, wobei es zu Läsionen kommt und wobei Tannin in die Körperhöhle gelangt.
Neisseria meningitidis causes most cases of bacterial meningitis. Meningococcal meningitis is a public health burden to both developed and developing countries throughout the world. There are a number of vaccines (polysaccharide-based, glycoconjugate, protein-based and combined conjugate vaccines) that are approved to target five of the six disease-causing serogroups of the pathogen. Immunization strategies have been effective at helping to decrease the global incidence of meningococcal meningitis. Researchers continue to enhance these efforts through discovery of new antigen targets that may lead to a broadly protective vaccine and development of new methods of homogenous vaccine production. This review describes current meningococcal vaccines and discusses some recent research discoveries that may transform vaccine development against N. meningitidis in the future.
Vaccination with meningococcal glycoconjugate vaccines has decreased the incidence of invasive meningitis worldwide. These vaccines contain purified capsular polysaccharides attached to a carrier protein. Because of derivatization chemistries used in the process, conjugation of polysaccharide to protein often results in heterogeneous mixtures. Well-defined vaccines are needed to determine the relationship between vaccine structure and generated immune response. Here, we describe efforts to produce well-defined vaccine candidates by chemoenzymatic synthesis. Chemically synthesized lactosides were substrates for recombinant sialyltransferase enzymes from Camplyobacter jejuni and Neisseria meningitidis serogroup C. These resulting oligosialic acids have the same α(2-9) sialic acid repeat structure as Neisseria polysaccharide capsule with the addition of a conjugatable azide aglycon. The degree of polymerization (DP) of carbohydrate products was controlled by inclusion of the inhibitor CMP-9-deoxy-NeuNAc. Polymers with estimated DP < 47 (median DP 25) and DP < 100 (median DP 51) were produced. The receptor binding domain of the tetanus toxin protein (TetHc) was coupled as a carrier to the enzymatically synthesized oligosialic acids. Recombinant TetHc was derivatized with an alkyne squarate. Protein modification sites were determined by trypsin proteolysis followed by LC/MS-MS(E) analysis of peptides. Oligosialic acid azides were conjugated to modified TetHc via click chemistry. These chemoenzymatically prepared glycoconjugates were reactive in immunoassays with specific antibodies against either group C polysaccharide or TetHc. Sera of mice immunized with oligosialic acid-TetHc glycoconjugates contained much greater levels of polysaccharide-reactive IgG than the sera of control mice receiving unconjugated oligosialic acids. There was no apparent difference between glycoconjugates containing oligosaccharides of DP < 47 and DP < 100. These results suggest that chemoenzymatic synthesis may provide a viable method for making defined meningococcal vaccine candidates.
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