The extent to which the oro-faecal route contributes to the transmission of SARS-CoV-2 is not established.

We systematically reviewed the evidence on the presence of infectious SARS-CoV-2 in faeces and other gastrointestinal sources by examining studies that used viral culture to investigate the presence of replication-competent virus in these samples. We conducted searches in the WHO COVID-19 Database, LitCovid, medRxiv, and Google Scholar for SARS-CoV-2 using keywords and associated synonyms, with a search date up to 28 November 2023.

We included 13 studies involving 229 COVID-19 subjects – providing 308 faecal or rectal swab SARS-CoV2 reverse transcription-polymerase chain reaction (RT-PCR)-positive samples tested with viral culture. The methods used for viral culture across the studies were heterogeneous. Three studies (two cohorts and one case series) reported observing replication-competent SARS-CoV-2 confirmed by quantitative RT-PCR (qPCR) and whole-genome sequencing, and qPCR including appropriate cycle threshold changes. Overall, six (1.9%) of 308 faecal samples subjected to cell culture showed replication-competent virus. One study found replication-competent samples from one immunocompromised patient. No studies were identified demonstrating direct evidence of oro-faecal transmission to humans.

Our review found a relatively low frequency of replication-competent SARS-CoV-2 in faecal and other gastrointestinal sources. Although it is biologically plausible, more research is needed using standardized cell culture methods, control groups, adequate follow-up, and robust epidemiologic methods, including whether secondary infections occurred, to determine the role of the oro-faecal route in the transmission of SARS-CoV-2.

The COVID-19 pandemic accelerated the development of decentralized clinical trials (DCT). DCT’s are an important and pragmatic method for assessing health outcomes yet comprise only a minority of clinical trials, and few published methodologies exist. In this report, we detail the operational components of COVID-OUT, a decentralized, multicenter, quadruple-blinded, randomized trial that rapidly delivered study drugs nation-wide. The trial examined three medications (metformin, ivermectin, and fluvoxamine) as outpatient treatment of SARS-CoV-2 for their effectiveness in preventing severe or long COVID-19. Decentralized strategies included HIPAA-compliant electronic screening and consenting, prepacking investigational product to accelerate delivery after randomization, and remotely confirming participant-reported outcomes. Of the 1417 individuals with the intention-to-treat sample, the remote nature of the study caused an additional 94 participants to not take any doses of study drug. Therefore, 1323 participants were in the modified intention-to-treat sample, which was the a priori primary study sample. Only 1.4% of participants were lost to follow-up. Decentralized strategies facilitated the successful completion of the COVID-OUT trial without any in-person contact by expediting intervention delivery, expanding trial access geographically, limiting contagion exposure, and making it easy for participants to complete follow-up visits. Remotely completed consent and follow-up facilitated enrollment.

Some charities are much more cost-effective than other charities, which means that they can save many more lives with the same amount of money. Yet most donations do not go to the most effective charities. Why is that? We hypothesized that part of the reason is that people underestimate how much more effective the most effective charities are compared with the average charity. Thus, they do not know how much more good they could do if they donated to the most effective charities. We studied this hypothesis using samples of the general population, students, experts, and effective altruists in five studies. We found that lay people estimated that among charities helping the global poor, the most effective charities are 1.5 times more effective than the average charity (Studies 1 and 2). Effective altruists, in contrast, estimated the difference to be factor 50 (Study 3) and experts estimated the factor to be 100 (Study 4). We found that participants donated more to the most effective charity, and less to an average charity, when informed about the large difference in cost-effectiveness (Study 5). In conclusion, misconceptions about the difference in effectiveness between charities is thus likely one reason, among many, why people donate ineffectively.

Research on marital quality and child well-being is currently limited by its common use of geographically constrained, homogenous, and often cross-sectional (or at least temporally limited) samples. We build upon previous work showing multiple trajectories of marital quality and data from the National Longitudinal Survey of Youth-1979 (NLSY79) regarding mothers and their children (inclusive of ages 5–14). We examine how indicators of child well-being are linked to parental trajectories of marital quality (happiness, communication, and conflict). Results showed children whose parents had consistently poor marital quality over the life course exhibited more internalizing and externalizing problems, poorer health, lower quality home environments, and lower math and vocabulary scores than children of parents in consistently higher-quality marriages. Group differences remained stable over time for child health, home environment, and vocabulary scores. Group differences for internalizing problems declined over time, whereas group differences increased for externalizing problems and math scores. Initial advantages for females across nearly all indicators of child well-being tended to shrink over time, with boys often moving slightly ahead by mid adolescence. We discuss the implications of these findings in regard to children's development and well-being and suggest treating marriage as a monolithic construct betrays important variation within marriage itself.

We study particle capture on an angled cylinder at a range of Péclet numbers. This system was inspired by the plumose antennae of certain species of male moths that intercept female pheromones at low Péclet numbers of 0.9–23. We use confocal microscopy to measure the branching patterns of 49 moths, spanning 12 families and two orders of magnitude in mass. Among the three levels of hierarchy in antennae, we find the middle level has a prevalent branching angle, $52^{\circ }\pm 12^{\circ }$ across our study set. Such intermediate branching angles are a surprising way to intercept molecules because they do not maximize the exposed surface area. To understand the benefits of angling cylinders into the flow, we study particle collection at high Péclet number using $10~\unicode[STIX]{x03BC}\text{m}$ drops that are several orders of magnitude larger than moth pheromones. Wind tunnel tests show that cylinders angled at $30^{\circ }{-}60^{\circ }$ are optimal for collection of particles, collecting 30 % more than when perpendicular to the flow. Simulations and smoke visualization show that angled cylinders bend incoming streamlines, creating a lingering effect near the cylinder that can enhance deposition by diffusion. We surmise that the optimal angle arises from a trade-off between the lingering effect, which decreases with increasing angle of the cylinder, and the cylinder’s increasing projected area as it is turned more perpendicular to the flow. Using a mathematical model, we show that only cylinders at low Péclet number show improved collection at intermediate angles. Thus, we cannot rationalize the high collection rates in our wind tunnel experiments at high Péclet number. We hope that our study will inspire more research into bio-inspired particle collection of angled surfaces, and find applications in sensors and filters.

Analysis of human remains and a copper band found in the center of a Late Archaic (ca. 5000–3000 cal BP) shell ring demonstrate an exchange network between the Great Lakes and the coastal southeast United States. Similarities in mortuary practices suggest that the movement of objects between these two regions was more direct and unmediated than archaeologists previously assumed based on “down-the-line” models of exchange. These findings challenge prevalent notions that view preagricultural Native American communities as relatively isolated from one another and suggest instead that wide social networks spanned much of North America thousands of years before the advent of domestication.

Leafy spurge is a troublesome, exotic weed in the northern Great Plains of the United States. Leafy spurge produces showy yellow bracts during June that give this weed a conspicuous appearance. A study was conducted to determine the feasibility of using remote sensing techniques to detect leafy spurge in this phenological stage. Study sites were located in North Dakota and Montana. Plant canopy reflectance measurements showed that leafy spurge had higher visible (0.63- to 0.69-μm) reflectance than several associated plant species. The conspicuous yellow bracts of leafy spurge gave it distinct yellow-green and pink images on conventional color and color-infrared aerial photographs, respectively. Leafy spurge also could be distinguished on conventional color video imagery where it had a golden yellow image response. Quantitative data obtained from digitized video images showed that leafy spurge had statistically different digital values from those of associated vegetation and soil. Computer analyses of video images showed/that light reflected from leafy spurge populations could be quantified from associated vegetation. This technique permits area estimates of leafy spurge populations. Large format conventional color photographs of Theodore Roosevelt National Park near Medora, ND were digitized and integrated with a geographic information system to produce a map of leafy spurge populations within the park that can be useful to monitor the spread or decline of leafy spurge.

In controlled-environment chambers, the scentless plant bug Niesthrea louisianica Sailer damaged reproductive structures of velvetleaf (Abutilon theophrasti Medik. # ABUTH) and reduced viable seed production by 98 to 99%, in comparison with insect-free control plants. The insect completed its life cycle on velvetleaf in two temperature regimes simulating warm growing-season conditions in Mississippi (29/23 C day/night) and Minnesota (24/18 C). Feeding by N. louisianica delayed flowering, capsule development, and capsule and seed maturation in biotypes of velvetleaf from Mississippi and Minnesota, in both temperature regimes. Numbers and weights of capsules and seed were lower in the infested plants. Augmentation of natural populations of N. louisianica to increase population density early in the growing season might be effective in reducing velvetleaf seed production.

In greenhouse experiments, sago pondweed plants were grown from three different size classes of tubers and treated with four levels of fluridone. Results indicate that although fluridone significantly reduced mean plant weight, the extent of the reduction in weight depended on the size of tuber from which the plant was grown. Mean plant weight was greater for plants exposed to fluridone (up to 0.5 mg/L) for 7 days, if the plants were initially from larger tubers (51 to 60 or 101 to 200 vs. 11 to 20 mg fresh weight). Mean plant length and the number of ramets/plant were affected in a similar manner. The results underscore the importance of specifying the size of tubers used in growth studies and contribute to understanding of the roles that biological factors play in regulating aquatic plant response to herbicide treatment.

Thirty-eight percent of monoecious hydrilla [Hydrilla verticillata (L.f.) Royle # HYLLI] grown from tubers produced new tubers after 28 days exposure to a 10-h photoperiod. One hundred percent of the plants grown at a 10-h photoperiod produced tubers by 56 days while only thirty-eight percent of those grown at a 12-h photoperiod did so. Plants grown at 14- or 16-h photoperiods did not produce tubers. Tubers appeared to be produced at the expense of new root and shoot tissue. Dioecious hydrilla (female) grown under similar conditions did not produce tubers by 56 days at any photoperiod examined. Relative growth rates (total dry weight) for both types did not differ with photoperiod and ranged between 81 ± 63 and 284 ± 52 mg·g-1·wk-1 (regression coefficient ± standard error; n = 30). In general, total chlorophyll (a+b) was greater for dioecious than for monoecious plants. The ratios of chlorophyll “a” to chlorophyll “b” and carotenoids to chlorophyll a changed with increasing photoperiod and plant age in a similar manner for both monoecious and dioecious plants.

The Makatea Islands in the southern Cook Islands consist of a degraded volcanic core surrounded by emergent “makatea” limestones. While much of this reefal limestone is of Tertiary age, the seawardmost reefs are late Pleistocene. Last-interglacial reefs (oxygen isotope substage 5e) identified by U-series dating reach 12.2 m on Atiu (mean age of three samples 126,000 ± 5000 yr B.P.), 9.8 m on Mitiaro (mean age of five samples 119,000 ± 3000 yr B.P.), 10.0–12.7 m on Mauke (mean age of four samples 128,000 + 5000, −4,000 yr B.P.), and 14.5–20.0 m on Mangaia (mean age of four samples 115,000 ± 7000 yr B.P.). On Atiu, Mauke, and Mitiaro a lower reef unit has been identified, and is separated from the overlying substage 5e reef by a sharp discontinuity, often with a crust of coralline algae. U-series dating from Atiu and Mauke indicates that this is a stage 7 reef formed in the penultimate interglaciation. The Makatea Islands have emerged as a result of flexure of the lithosphere in response to loading by the Pleistocene volcanic island of Rarotonga. Isolated outcrops of makatea limestone on Rarotonga reach 3.5 m and are probably of substage 5e age. Elastic and viscoelastic models of lithospheric flexure predict that much of the compensatory movement should occur shortly after the emplacement of the load. However, the age and elevation of late Quaternary reefs on the southern Cook Islands, where a Pleistocene volcanic island has loaded relatively old ocean floor (>80 myr), indicate that differential uplift has been continuing over the last 250,000 yr.

Yellow starthistle represents one of the most spectacular examples of biological invasion in the western United States. However, the mechanisms leading to its success have not been clearly elucidated. Although its success has been attributed to superior competitive ability, few competition studies have been performed with yellow starthistle to test this assertion. Yellow starthistle and wild oat (a dominant component of California annual grasslands) were grown in monocultures and mixtures to assess the strength of competitive interactions between them. For either species, intraspecific competition exerted a greater influence over mean plant weight than did interspecific competition. A companion study revealed temporal separation in the phenology of these plants, explaining the weak role of interspecific competition. Additional measurements of growth and soil moisture dynamics in large 270-cm-tall by 50-cm-diam polyvinyl chloride columns also showed a lack of interspecific competition and confirmed that water use patterns differed between these species, indicating niche partitioning. Wild oat reduced soil moisture to 5% but only to a depth of approximately 150 cm. Yellow starthistle depleted soil moisture to less than 5% throughout the column to a depth of at least 270 cm. These patterns were present when wild oat and yellow starthistle were grown individually or together in the columns, indicating that yellow starthistle had a greater impact on soil moisture and to greater depths. Yellow starthistle's invasion of grasslands in California does not appear to be due to superior competitive ability, but may be due to its ability to access deeper soil moisture. These results support the empty niche hypothesis that implies that invasive species are successful in new habitats because they access resources not available to resident species.

A species' successful invasion into a new site depends on its ability to persist in the local environment. An experiment was conducted to examine the response of giant reed to intermittent periods of shading for 2 yr. Results indicate that giant reed persisted when exposed to significant shading (i.e., 90% reduction of full sun) and that shading also caused changes in a number of plant characteristics, such as stem height, internode length, leaf nitrogen, leaf chlorophyll content, specific leaf area, total leaf area per plant, and leaf life span. Estimates of leaf photosynthetic rates did not differ across shade levels. Giant reed's ability to persist and grow under intermittent low-light conditions implies that plants would be poised to take advantage of sun flecks and disturbances that create gaps within the resident plant community.

Giant reed is an invasive plant of riparian habitats throughout California and the United States. Glyphosate is approved for controlling giant reed in California. Sources indicate that 1.5% to 5% glyphosate solutions are effective at controlling giant reed. There is little published data on the relative efficacy of different concentrations of glyphosate which can be used to select an appropriate application regime for California habitats. We conducted two field experiments to test the hypothesis that glyphosate concentrations of 1.5%, 3%, and 5% applied as foliar sprays were equally effective at killing giant reed plants. Leaf chlorophyll content and the proportion of living stems declined significantly following treatment with 1.5% or greater solutions of glyphosate. New stems were observed the spring following treatment for plants treated with 1.5% glyphosate. No new stems were observed for plants treated with either 3% or 5% glyphosate. A treatment that included “bending and breaking” stems prior to treatment with 5% glyphosate provided control similar to 5% glyphosate alone. There was no there evidence that plants sprayed with only a mixture of the surfactant (Agridex), water, and a marking dye were affected beyond the short-term. These results indicate that 3% or 5% foliar applications with glyphosate were the most effective and consistent treatments for killing giant reed with a single late-season application. This result is especially important if the goal of the treatment program is to minimize the number of treatments, thus reducing labor costs and minimizing impacts on sensitive habitats by reducing the number of site visits.