Longitudinal Trends in Cardiovascular Risk Factor Profiles and Complications Among Patients Hospitalized for COVID-19 Infection: Results From the American Heart Association COVID-19 Cardiovascular Disease Registry.

Background: The COVID-19 pandemic has evolved through multiple phases characterized by new viral variants, vaccine development, and changes in therapies. It is unknown whether rates of cardiovascular disease (CVD) risk factor profiles and complications have changed over time.

Methods: We analyzed the American Heart Association COVID-19 CVD registry, a national multicenter registry of hospitalized adults with active COVID-19 infection.

Breeding systems of naturalized versus indigenous species provide support for Baker's law on Pohnpei island.

The factors that facilitate successful colonization of islands should be especially evident where the establishment filter is strongest. Colonizers of small, remote oceanic islands should be initially rare, extremely mate-limited and often without pollinators. Hence, plant communities on such islands should reflect an establishment history in which young 'naturalized' species are most likely to display self-compatibility and autonomous selfing, whereas 'indigenous' species may exhibit more diverse reproductive strategies.

Consequences of whole genome duplication for 2n pollen performance.

The vegetative cell of the angiosperm male gametophyte (pollen) functions as a free-living, single-celled organism that both produces and transports sperm to egg. Whole-genome duplication (WGD) should have strong effects on pollen because of the haploid to diploid transition and because of both genetic and epigenetic effects on cell-level phenotypes. To disentangle historical effects of WGD on pollen performance, studies can compare 1n pollen from diploids to neo-2n pollen from diploids and synthetic autotetraploids to older 2n pollen from established neo-autotetraploids.

Treatment and Outcomes of Patients With Ischemic Stroke During COVID-19: An Analysis From Get With The Guidelines-Stroke.

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Racial and Ethnic Differences in Presentation and Outcomes for Patients Hospitalized With COVID-19: Findings From the American Heart Association's COVID-19 Cardiovascular Disease Registry.

Background: The coronavirus disease 2019 (COVID-19) pandemic has exposed longstanding racial and ethnic inequities in health risks and outcomes in the United States. We aimed to identify racial and ethnic differences in presentation and outcomes for patients hospitalized with COVID-19.

Methods: The American Heart Association COVID-19 Cardiovascular Disease Registry is a retrospective observational registry capturing consecutive patients hospitalized with COVID-19.

American Heart Association COVID-19 CVD Registry Powered by Get With The Guidelines.

Background: In response to the public health emergency created by the coronavirus disease 2019 (COVID-19) pandemic, American Heart Association volunteers and staff aimed to rapidly develop and launch a resource for the medical and research community to expedite scientific advancement through shared learning, quality improvement, and research. In <4 weeks after it was first announced on April 3, 2020, AHA's COVID-19 CVD Registry powered by Get With The Guidelines received its first clinical records.

Methods And Results: Participating hospitals are enrolling consecutive hospitalized patients with active COVID-19 disease, regardless of CVD status.

For things to stay the same, things must change: polyploidy and pollen tube growth rates.

Background And Aims: Pollen tube growth rate (PTGR) is an important single-cell performance trait that may evolve rapidly under haploid selection. Angiosperms have experienced repeated cycles of polyploidy (whole genome duplication), and polyploidy has cell-level phenotypic consequences arising from increased bulk DNA amount and numbers of genes and their interactions. We sought to understand potential effects of polyploidy on several underlying determinants of PTGR - pollen tube dimensions and construction rates - by comparing diploid-polyploid near-relatives in Betula (Betulaceae) and Handroanthus (Bignoniaceae).

How does genome size affect the evolution of pollen tube growth rate, a haploid performance trait?

Premise: Male gametophytes of most seed plants deliver sperm to eggs via a pollen tube. Pollen tube growth rates (PTGRs) of angiosperms are exceptionally rapid, a pattern attributed to more effective haploid selection under stronger pollen competition. Paradoxically, whole genome duplication (WGD) has been common in angiosperms but rare in gymnosperms.

Evolution of development of pollen performance.

With the origin of pollination in ancient seed plants, the male gametophyte ("pollen") began to evolve a new and unique life history stage, the progamic phase, a post-pollination period in which pollen sexual maturation occurs in interaction with sporophyte-derived tissues. Pollen performance traits mediate the timing of the fertilization process, often in competition with other pollen, via the speed of pollen germination, sperm development, and pollen tube growth. Studies of pollen development rarely address the issue of performance or its evolution, which involves linking variation in developmental rates to relative fitness within populations or to adaptations on a macroevolutionary scale.

Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences.

The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources.

Evolutionary origins of pectin methylesterase genes associated with novel aspects of angiosperm pollen tube walls.

The early evolution of angiosperms was marked by a number of innovations of the reproductive cycle including an accelerated fertilization process involving faster transport of sperm to the egg via a pollen tube. Fast pollen tube growth rates in angiosperms are accompanied by a hard shank-soft tip pollen tube morphology. A critical actor in that morphology is the wall-embedded enzyme pectin methylesterase (PME), which in type II PMEs is accompanied by a co-transcribed inhibitor, PMEI.

Pollen--tiny and ephemeral but not forgotten: New ideas on their ecology and evolution.

Ecologists and evolutionary biologists have been interested in the functional biology of pollen since the discovery in the 1800s that pollen grains encompass tiny plants (male gametophytes) that develop and produce sperm cells. After the discovery of double fertilization in flowering plants, botanists in the early 1900s were quick to explore the effects of temperature and maternal nutrients on pollen performance, while evolutionary biologists began studying the nature of haploid selection and pollen competition. A series of technical and theoretic developments have subsequently, but usually separately, expanded our knowledge of the nature of pollen performance and how it evolves.

Economy, efficiency, and the evolution of pollen tube growth rates.

Premise: Pollen tube growth rate (PTGR) is an important aspect of male gametophyte performance because of its central role in the fertilization process. Theory suggests that under intense competition, PTGRs should evolve to be faster, especially if PTGR accurately reflects gametophyte quality. Oddly, we know remarkably little about how effectively the work of tube construction is translated to elongation (growth and growth rate).

Repeated evolution of tricellular (and bicellular) pollen.

Premise Of Study: Male gametophytes of seed plants are sexually immature at the time they are dispersed as pollen, but approximately 30% of flowering plants have tricellular pollen containing fully formed sperm at anthesis. The classic study of Brewbaker (1967: American Journal of Botany 54: 1069-1083) provided a powerful confirmation of the long-standing hypothesis that tricellular pollen had many parallel and irreversible origins within angiosperms. We readdressed the main questions of that study with modern comparative phylogenetic methods.

The evolution of pollen germination timing in flowering plants: Austrobaileya scandens (Austrobaileyaceae).

Background And Aims: The pollination to fertilization process (progamic phase) is thought to have become greatly abbreviated with the origin of flowering plants. In order to understand what developmental mechanisms enabled the speeding of fertilization, comparative data are needed from across the group, especially from early-divergent lineages. I studied the pollen germination process of Austrobaileya scandens, a perennial vine endemic to the Wet Tropics area of northeastern Queensland, Australia, and a member of the ancient angiosperm lineage, Austrobaileyales.

Pollen tube development in two species of Trithuria (Hydatellaceae) with contrasting breeding systems.

Trithuria (Hydatellaceae; Nymphaeales) is unique among early-divergent angiosperms in that its species are extremely small and most have exceptionally short, annual life histories. Given the evolution of these extremes of size and development, we sought to understand whether post-pollination processes still varied predictably with breeding system in Trithuria. To address this question, we studied two Western Australian species, Trithuria austinensis (dioecious, obligately outcrossing) and Trithuria submersa (bisexual, highly selfing).

Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS) gene expression patterns.

Background: A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan) walls and septae (callose plugs) of angiosperm pollen tubes.

Reproductive ecology of the basal angiosperm Trithuria submersa (Hydatellaceae).

Background And Aims: Trithuria, the sole genus in the family Hydatellaceae, is an important group for understanding early angiosperm evolution because of its sister relationship to the ancient lineage, Nymphaeales (water lilies). Although also aquatic, Trithuria differs from water lilies in that all species are extremely small, and most have an annual life form and grow in seasonal wetlands. Very little is known about their reproductive ecology.

Pollination biology of basal angiosperms (ANITA grade).

The first three branches of the angiosperm phylogenetic tree consist of eight families with ∼201 species of plants (the ANITA grade). The oldest flower fossil for the group is dated to the Early Cretaceous (115-125 Mya) and identified to the Nymphaeales. The flowers of extant plants in the ANITA grade are small, and pollen is the edible reward (rarely nectar or starch bodies).

Amborella trichopoda (Amborellaceae) and the evolutionary developmental origins of the angiosperm progamic phase.

A remarkable number of the defining features of flowering plants are expressed during the life history stage between pollination and fertilization. Hand pollinations of Amborella trichopoda (Amborellaceae) in New Caledonia show that when the stigma is first receptive, the female gametophyte is near maturity. Pollen germinates within 2 h, and pollen tubes with callose walls and plugs grow entirely within secretions from stigma to stylar canal and ovarian cavity.

Novelties of the flowering plant pollen tube underlie diversification of a key life history stage.

The origin and rapid diversification of flowering plants has puzzled evolutionary biologists, dating back to Charles Darwin. Since that time a number of key life history and morphological traits have been proposed as developmental correlates of the extraordinary diversity and ecological success of angiosperms. Here, I identify several innovations that were fundamental to the evolutionary lability of angiosperm reproduction, and hence to their diversification.

Embryology of Manekia naranjoana (Piperaceae) and the origin of tetrasporic, 16-nucleate female gametophytes in Piperales.

The vast majority of flowering plant seeds contain a triploid endosperm formed by fertilization of a monosporic, Polygonum-type female gametophyte. However, evolutionary transitions to six other genetic constructs of endosperm are widespread, and six of seven known patterns are found in the order Piperales. Within Piperaceae, Manekia has not been described, and we report its female gametophyte to be tetrasporic and 16-nucleate at maturity.