South America

Durante el siglo XIX, los territorios de América Latina se enfrentaron a procesos de independencia, esto significó un cambio en el nuevo orden del sub continente pues implicó cambios en los valores nacionales, en el poder político administrativo y constantes renovaciones de las entidades territoriales. Este mapa de Sur América fue publicado en 1829 de acuerdo al acta de Congreso número 20 del Estado de Connecticut por D.F Robison; contiene división político administrativa, información de hidrografía, relieves, ciudades y puertos principales. Presenta longitud con respecto al meridiano de Greeenwich

Map of the western states to illustrate Olney's school geography.

Map shows counties, railroads, canals, major cities, towns, battlegrounds, and mining activity for Missouri, Illinois, Indiana, Ohio, Kentucky, and parts of Iowa, Michigan, and Wisconsin Territory. Includes explanation and length of waterbodies. Scale not given

Map of the Middle States: to illustrate Olney's School Geography.

Map shows county boundaries, railroads, canals, notable physical features, cities and towns in the early nineteenth century middle Atlantic states. Includes explanation, distances, and population statistics. Relief shown by hachures. Scale not given

Map of Mexico, Central America, New Granada, Venezuela, and the West Indies : to illustrate Olney's school geography.

Map shows mid-nineteenth century geography and cities in Mexico, Central America, Cuba, and part of the southwestern United States. Includes mileage information between selected United States cities. Inset: "Isthmus of Darien." Relief shown by hachures. Scale information not indicated

Map of Texas : To Illustrate Olney's School of Geography

Map of the eastern portion of Texas with all of the counties outlined and labeled. The map has rivers and geographic landforms marked (relief is shown by hachures). Bordering portions of "Indian Territory" and Mexico are shown to the north and south. Prime meridians: Greenwich and Washington

The family book of history; comprising a concise view of the most interesting and important events in the history of all the civilized nations of the earth. Compiled from the most authentic sources, and alphabetically arranged.

Mode of access: Internet

Estimating the Effect of Social Distancing Interventions on COVID-19 in the United States

Since its global emergence in 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused multiple epidemics in the United States. When medical treatments for the virus were still emerging and a vaccine was not yet available, state and local governments sought to limit its spread by enacting various social-distancing interventions, such as school closures and lockdowns; however, the effectiveness of these interventions was unknown. We applied an established, semimechanistic Bayesian hierarchical model of these interventions to the spread of SARS-CoV-2 from Europe to the United States, using case fatalities from February 29, 2020, up to April 25, 2020, when some states began reversing their interventions. We estimated the effects of interventions across all states, contrasted the estimated reproduction numbers before and after lockdown for each state, and contrasted the predicted number of future fatalities with the actual number of fatalities as a check of the model\u27s validity. Overall, school closures and lockdowns were the only interventions modeled that had a reliable impact on the time-varying reproduction number, and lockdown appears to have played a key role in reducing that number to below 1.0. We conclude that reversal of lockdown without implementation of additional, equally effective interventions will enable continued, sustained transmission of SARS-CoV-2 in the United States

Memantine binding to a superficial site on NMDA receptors contributes to partial trapping

Although many nervous system disorders are associated with N-methyl-d-aspartate (NMDA) receptor overactivation, pharmacological inhibition of NMDA receptors has typically demonstrated limited clinical value due to debilitating psychotomimetic side-effects. Memantine, however, induces far fewer behavioural side-effects than other NMDA receptor channel blockers such as ketamine, and slows the progressive cognitive decline associated with Alzheimer's disease. Memantine and ketamine inhibit NMDA receptors with similar affinity and kinetics. A prominent mechanistic difference between memantine and ketamine is the degree to which they are ‘trapped’ within the closed channel of NMDA receptors following removal of agonist: ketamine becomes trapped in nearly all NMDA receptors to which it was bound before agonist removal, whereas some bound memantine molecules dissociate after agonist removal, a phenomenon called partial trapping. Here we investigated the mechanism underlying partial trapping of memantine by recombinant NR1/2A NMDA receptors. We found that memantine dissociation from NR1/2A receptors after agonist removal (the process that results in partial trapping) followed an exponential time course with τ= 0.79 ± 0.32 s. Neither membrane voltage depolarization nor maintained presence of memantine after agonist removal affected partial trapping, suggesting that partial trapping does not result from memantine escape through open channels. We tested the hypothesis that partial trapping results from binding of memantine to two sites, a superficial ‘non-trapping’ site and a deep ‘trapping’ site, which cannot be occupied simultaneously. This hypothesis was supported by the lack of ketamine binding to the superficial site, the voltage dependence of partial trapping, and the effect on partial trapping of a mutation near the deep site. The superficial binding site for memantine may, by causing partial trapping, contribute to memantine's unique therapeutic utility