Implications of Delayed Reopening in Controlling the COVID-19 Surge in Southern and West-Central USA

In the wake of the rapid surge in the COVID-19-infected cases seen in Southern and West-Central USA in the period of June-July 2020, there is an urgent need to develop robust, data-driven models to quantify the effect which early reopening had on the infected case count increase. In particular, it is imperative to address the question: How many infected cases could have been prevented, had the worst affected states not reopened early? To address this question, we have developed a novel COVID-19 model by augmenting the classical SIR epidemiological model with a neural network module. The model decomposes the contribution of quarantine strength to the infection time series, allowing us to quantify the role of quarantine control and the associated reopening policies in the US states which showed a major surge in infections. We show that the upsurge in the infected cases seen in these states is strongly corelated with a drop in the quarantine/lockdown strength diagnosed by our model. Further, our results demonstrate that in the event of a stricter lockdown without early reopening, the number of active infected cases recorded on 14 July could have been reduced by more than 40% in all states considered, with the actual number of infections reduced being more than 100,000 for the states of Florida and Texas. As we continue our fight against COVID-19, our proposed model can be used as a valuable asset to simulate the effect of several reopening strategies on the infected count evolution, for any region under consideration.

Phylogenetic biogeography of Leptohyphes (Ephemeroptera: Leptohyphidae)

Leptohyphes Eaton is one of the most species-rich American genera in Ephemeroptera, with 45 valid species distributed from south-central USA to Patagonia. Most species are distributed in central and northern Andes. Nymphs are frequent and abundant in mountain streams. We present a parsimony-based morphological phylogeny for the genus. Specific geographic records were studied using Hovenkamp’s protocol (barrier biogeography). Leptohyphes was recovered as a monophyletic group. The most ancient disjunction found in Leptohyphes separated Tepui-area from the rest of the Americas. Other interesting vicariant events were found, including the separation of eastern Atlantic mountains (Mata Atlantica) from the Andes; oriental and occidental slopes of the Andes; northern from central Andes; and northern Andes from Central and North America. An ancient tropical South American origin for the genus is supported, with a more recent diversification due to Andean orogeny. Clades and terminals reaching North America include few independent events of more recent range expansions.

A Comparison of the Characteristics of Drought during the Late 20th and Early 21st Centuries over Eastern Europe, Western Russia and Central North America

The character of the atmospheric general circulation during summer-season droughts over Eastern Europe/Western Russia and North America during the late twentieth and early twenty first century is examined here. A criterion to examine atmospheric drought events that encompassed the summer season (an important part of the growing season) was used to determine which years were driest, using precipitation, evaporation, and areal coverage. The relationship between drought and the character of the atmosphere, using the Dzerzeevsky weather and climatic classification scheme, atmospheric blocking, teleconnections, and information entropy, was used to study the atmospheric dynamics. The National Centers for Environmental Prediction (NCEP) re-analyses dataset archived at the National Center for Atmospheric Research (NCAR) in Boulder, CO, USA, is used to examine the synoptic character and calculate the dynamic quantities for these dry events. The results demonstrate that extreme droughts over North America are associated with a long warm and dry period of weather and the development of a moderate ridge over the Central USA driven by surface processes. These were more common in the late 20th century. Extreme droughts over Eastern Europe and Western Russia are driven by the occurrence of prolonged blocking episodes, as well as surface processes, and have become more common during the 21st century.

Effects of statewide stay-at-home orders on COVID-19 cases and deaths in the central USA

PurposeThis study seeks to determine the effects of stay-at-home orders in Spring 2020 on COVID-19 cases and deaths in the Central USA by comparing counties and health service areas that were and that were not subject to statewide orders.Design/methodology/approachThis study estimates the effects of statewide stay-at-home orders on new COVID-19 cases and deaths within 19 central states, of which 14 had stay-at-home orders. It uses synthetic control analysis and nearest neighbor matching to estimate the effects at two geographic levels: counties and health service areas.FindingsStatewide stay-at-home orders significantly reduced the number of new COVID-19 cases in the Central USA starting about three weeks after their effective dates; during the fourth week after their effective dates, the orders reduced the number of new cases per capita by 31%–57%. Statewide stay-at-home orders did not reduce the number of new COVID-19 deaths in the Central USA.Social implicationsThe main purpose of stay-at-home orders in Spring 2020 was to “flatten the curve” so that hospitalizations would not exceed capacity. It is likely that stay-at-home orders in the Central USA reduced hospitalizations to some extent, although the effect on hospitalizations was likely smaller than the effect on cases.Originality/valueThis is the first study of stay-at-home orders in the USA to limit the population to a group of interior states. All coastal states had statewide stay-at-home orders and comparing coastal states with orders to interior states without them may be problematic.

Biogeography of ITS Variation in the Helenium autumnale (Asteraceae) Species Complex

Abstract—We used ITS sequences as species barcodes to evaluate 127 samples of 12 Helenium species from the eastern and central USA, focusing on a species complex of H. autumnale (76 sequences from 11 U.S. states and two Canadian provinces), the federally “threatened” H. virginicum, now recommended for delisting (30 sequences from three U.S. states), and H. flexuosum (11 sequences from four U.S. states). ITS sequences confirmed most species identifications and supported the presence of the first population of the “threatened” endemic Missouri-Virginia disjunct, Helenium virginicum, in Indiana. Because the Indiana plants grow in a restored wetland, have a cpDNA haplotype previously known only from Missouri, with a morphology similar to Missouri variants, and an herbarium search for additional populations in Indiana found none, it is unclear whether the Indiana population is natural or planted. The presence of a putative sister lineage to H. virginicum thought to exist on the Bruce Peninsula, Ontario, Canada, was not supported after sequencing 36 plants with the sister morphology that grew there along 18 km of beach fens and finding they had H. autumnale sequences. Fine-scale biogeographic patterns of intraspecific sequence variation were found mostly in H. autumnale, with centers of different base site polymorphisms found in northern North America and the Missouri Ozarks. As in a previous study, we found DNA evidence of hybridization between Helenium species in Missouri. We offer hypotheses to explain the biogeography of North American Helenium, focusing on the three species that compose the H. autumnale species complex and suggesting that H. autumnale may be a compilospecies showing incomplete lineage sorting. We encourage exploration of more Helenium species and their conspecific populations in search of fine-scale ITS base site polymorphisms to reveal emerging lineages and resolve the origins and evolutionary implications of these biogeographic patterns.

Greenhouse gases drove the increasing trends in spring precipitation across the central USA

The central USA experienced major flooding during spring 2019, with both the Missouri and Mississippi Rivers at major flood stage at several locations, causing levees to breach and widespread flooding. Here, we examine the total precipitation responsible for the spring 2019 flooding across the central USA from the perspective of weather types. We focus on the weather type (referred to as ‘Midwest Water Hose’ (MWH) (Zhang and Villarini. 2019 Climate Dynamics 53 , 4217–4232. ( doi:10.1007/s00382-019-04783-4 ))) that contributes the most to the total precipitation across the central USA. This weather type contributed to more than 70% of the total precipitation received across much of this region during January–May 2019, and it has been occurring increasingly frequently over the past 40 years. Furthermore, we found that climate model experiments with the historical change of greenhouse gas concentration can well reproduce the observed rising trend, while this is not the case for the natural forcing experiments. Therefore, the rising trend and the high frequency of the MWH can be mainly attributed to the rising greenhouse gases caused by human activities, rather than natural forcing. This article is part of a discussion meeting issue ‘Intensification of short-duration rainfall extremes and implications for flash flood risks’.