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No-till planting organic soybean [Glycine max (L.) Merr.] into roller-crimped cereal rye (Secale cereale L.) can have several advantages over traditional tillage-based organic production. However, suboptimal cereal rye growth in fields with large populations of weeds may result in reduced weed suppression, weed–crop competition, and soybean yield loss. Ecological weed management theory suggests that integrating multiple management practices that may be weakly effective on their own can collectively provide high levels of weed suppression. In 2021 and 2022, a field experiment was conducted in central New York to evaluate the performance of three weed management tactics implemented alone and in combination in organic no-till soybean planted into both cereal rye mulch and no mulch: (1) increasing crop seeding rate, (2) interrow mowing, and (3) weed electrocution. A nontreated control treatment that did not receive any weed management and a weed-free control treatment were also included. Cereal rye was absent from two of the five fields where the experiment was repeated; however, the presence of cereal rye did not differentially affect results, and thus data were pooled across fields. All treatments that included interrow mowing reduced weed biomass by at least 60% and increased soybean yield by 14% compared with the nontreated control. The use of a high seeding rate or weed electrocution, alone or in combination, did not improve weed suppression or soybean yield relative to the nontreated control. Soybean yield across all treatments was at least 22% lower than in the weed-free control plot. Future research should explore the effects of the tactics tested on weed population and community dynamics over an extended period. Indirect effects from interrow mowing and weed electrocution should also be studied, such as the potential for improved harvestability, decreased weed seed production and viability, and the impacts on soil organisms and agroecosystem biodiversity.
This article emerged as the human species collectively have been experiencing the worst global pandemic in a century. With a long view of the ecological, economic, social, and political factors that promote the emergence and spread of infectious disease, archaeologists are well positioned to examine the antecedents of the present crisis. In this article, we bring together a variety of perspectives on the issues surrounding the emergence, spread, and effects of disease in both the Americas and Afro-Eurasian contexts. Recognizing that human populations most severely impacted by COVID-19 are typically descendants of marginalized groups, we investigate pre- and postcontact disease vectors among Indigenous and Black communities in North America, outlining the systemic impacts of diseases and the conditions that exacerbate their spread. We look at how material culture both reflects and changes as a result of social transformations brought about by disease, the insights that paleopathology provides about the ancient human condition, and the impacts of ancient globalization on the spread of disease worldwide. By understanding the differential effects of past epidemics on diverse communities and contributing to more equitable sociopolitical agendas, archaeology can play a key role in helping to pursue a more just future.
Background: Shared Healthcare Intervention to Eliminate Life-threatening Dissemination of MDROs in Orange County, California (SHIELD OC) was a CDC-funded regional decolonization intervention from April 2017 through July 2019 involving 38 hospitals, nursing homes (NHs), and long-term acute-care hospitals (LTACHs) to reduce MDROs. Decolonization in NH and LTACHs consisted of universal antiseptic bathing with chlorhexidine (CHG) for routine bathing and showering plus nasal iodophor decolonization (Monday through Friday, twice daily every other week). Hospitals used universal CHG in ICUs and provided daily CHG and nasal iodophor to patients in contact precautions. We sought to evaluate whether decolonization reduced hospitalization and associated healthcare costs due to infections among residents of NHs participating in SHIELD compared to nonparticipating NHs. Methods: Medicaid insurer data covering NH residents in Orange County were used to calculate hospitalization rates due to a primary diagnosis of infection (counts per member quarter), hospital bed days/member-quarter, and expenditures/member quarter from the fourth quarter of 2015 to the second quarter of 2019. We used a time-series design and a segmented regression analysis to evaluate changes attributable to the SHIELD OC intervention among participating and nonparticipating NHs. Results: Across the SHIELD OC intervention period, intervention NHs experienced a 44% decrease in hospitalization rates, a 43% decrease in hospital bed days, and a 53% decrease in Medicaid expenditures when comparing the last quarter of the intervention to the baseline period (Fig. 1). These data translated to a significant downward slope, with a reduction of 4% per quarter in hospital admissions due to infection (P < .001), a reduction of 7% per quarter in hospitalization days due to infection (P < .001), and a reduction of 9% per quarter in Medicaid expenditures (P = .019) per NH resident. Conclusions: The universal CHG bathing and nasal decolonization intervention adopted by NHs in the SHIELD OC collaborative resulted in large, meaningful reductions in hospitalization events, hospitalization days, and healthcare expenditures among Medicaid-insured NH residents. The findings led CalOptima, the Medicaid provider in Orange County, California, to launch an NH incentive program that provides dedicated training and covers the cost of CHG and nasal iodophor for OC NHs that enroll.
Disclosures: Gabrielle M. Gussin, University of California, Irvine, Stryker (Sage Products): Conducting studies in which contributed antiseptic product is provided to participating hospitals and nursing homes. Clorox: Conducting studies in which contributed antiseptic product is provided to participating hospitals and nursing homes. Medline: Conducting studies in which contributed antiseptic product is provided to participating hospitals and nursing homes. Xttrium: Conducting studies in which contributed antiseptic product is provided to participating hospitals and nursing homes.
To this date ψ Per is the only classical Be star that was angularly resolved in radio (by the VLA at λ = 2 cm). Gaussian fit to the azimuthally averaged visibility data indicates a disk size (FWHM) of ~500 stellar radii (Dougherty & Taylor 1992). Recently, we obtained new multi-band cm flux density measurements of ψ Per from the enhanced VLA. We modeled the observed spectral energy distribution (SED) covering the interval from ultraviolet to radio using the Monte Carlo radiative transfer code HDUST (Carciofi & Bjorkman 2006). An SED turndown, that occurs between far-IR and radio wavelengths, is explained by a truncated viscous decretion disk (VDD), although the shallow slope of the radio SED suggests that the disk is not simply cut off, as is assumed in our model. The best-fit size of a truncated disk derived from the modeling of the radio SED is 100+5−15 stellar radii, which is in striking contrast with the result of Dougherty & Taylor (1992). The reasons for this discrepancy are under investigation.
Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.
It has long been recognized that tidal interaction between the components of close binaries will tend to circularize their orbits (e.g., Darwin 1879; Zahn 1977). In fact observations show an abundance of circular orbits in binaries with periods of days. However, the dissipation mechanism required for circularization, the timescales involved, and the dependence on period, mass, evolutionary state, and initial eccentricity of the system remain subjects of debate.
Circularization theories such as Zahn (1977) state that circularization in binaries where at least one component possesses a convective envelope is much more efficient than in binaries where both stars have radiative envelopes. Giuiricin et al. (1984; GMM) studied the period-eccentricity distribution of O-, B- and A-type binaries and argued that the observations were consistent with Zahn’s theory for radiative envelopes. But recently, Tassoul (1988) has presented an alternative circularization theory with similarly efficient circularization in radiative- and convective-envelope binaries. In addition, period-eccentricity distributions for many samples of main-sequence convective-envelope binaries are now available. Here we reconsider the observed short-period eccentricity distribution of radiative-envelope binaries in light of these new observations and theory. Specifically, we investigate the period-eccentricity distribution of a sample of binaries with A-type primary stars.
Intense efforts have been directed at the stabilization of proteins because of their potential uses in organic synthesis, diagnostics, and the pharmaceutical industry. These efforts have resulted in a number of methods to stabilize enzymes including adsorbtion on inert supports or ion exchange resins, entrapment within a gel (with or without crosslinking of the gel or protein), covalent attachment to beads or polymeric supports, inclusion in micelles, chemical derivatization of the protein and mutagenesis. However, these methods do not provide a general approach to solving the problem of protein stability. We believed that the multi-site attachment of a carbohydrate-based macromolecule to the surface of a protein would provide structural stability and a water-like microenvironment for the protein under harsh reaction conditions.
A variety of ceramic materials have been heated in various microwave excited plasmas at reduced pressures. Temperatures were measured by optical fiber thermometry. Specimen heating was accomplished by direct contact with the plasma, as well as direct coupling withthe microwave energy, although the latter was screened heavily by the plasma. Higher specimen temperatures were achieved in polyatomic gases which have greater reactional enthalpy. In general, insulating materials achieved higher temperatures than semiconducting or covalently bonded materials.
The polymerization of a series of new monomers composed of carbohydrates functionalized with polymerizable side-groups gave high molecular weight water-soluble materials. The preparation of the monomers using both chemical and enzymatic methods allowed complete stereo- and regiochemical control of the composition of the monomers.
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