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Field studies were conducted in 2019 and 2020 to compare the effects of shade cloth light interception and Palmer amaranth (Amaranthus palmeri S. Watson) competition on ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Treatments consisted of a seven by two factorial arrangement, in which the first factor included shade cloth with an average measured light interception of 41%, 59%, 76%, and 94% and A. palmeri thinned to 0.6 or 3.1 plants m−2 or a nontreated weed-free check; and the second factor included shade cloth or A. palmeri removal timing at 6 or 10 wk after planting (WAP). Amaranthus palmeri light interception peaked around 710 to 840 growing degree days (base 10 C) (6 to 7 WAP) with a maximum light interception of 67% and 84% for the 0.6 and 3.1 plants m−2 densities, respectively. Increasing shade cloth light interception by 1% linearly increased yield loss by 1% for No. 1, jumbo, and total yield. Yield loss increased by 36%, 23%, and 35% as shade cloth removal was delayed from 6 to 10 WAP for No. 1, jumbo, and total yield, respectively. F-tests comparing reduced versus full models of yield loss provided no evidence that the presence of yield loss from A. palmeri light interception caused yield loss different than that explained by the shade cloth at similar light-interception levels. Results indicate that shade cloth structures could be used to simulate Covington sweetpotato yield loss from A. palmeri competition, and light interception could be used as a predictor for expected yield loss from A. palmeri competition.
The origin and stability of ground ice in the stable uplands of the McMurdo Dry Valleys remains poorly understood, with most studies focusing on the near-surface permafrost. The 2016 Friis Hills Drilling Project retrieved five cores reaching 50 m depth in mid-Miocene permafrost, a period when Antarctica transitioned to a hyper-arid environment. This study characterizes the cryostratigraphy of arguably the oldest permafrost on Earth and assesses 15 Myr of ground ice evolution using the REGO model. Four cryostratigraphic units were identified: 1) surficial dry permafrost (0–30 cm), 2) ice-rich to ice-poor permafrost (0.3–5.0 m) with high solute load and δ18O values (-16.2 ± 1.8‰) and low D-excess values (-65.6 ± 4.3‰), 3) near-dry permafrost (5–20 m) and 4) ice-poor to ice-rich permafrost (20–50 m) containing ice lenses with low solute load and δ18O values (-34.6 ± 1.2‰) and D-excess of 6.9 ± 2.6‰. The near-surface δ18O profile of ground ice is comparable to other sites in the stable uplands, suggesting that this ice is actively responding to changing surface environmental conditions and challenging the assumption that the surface has remained frozen for 13.8 Myr. The deep ice lenses probably originate from the freezing of meteoric water during the mid-Miocene, and their δ18O composition suggests mean annual air temperatures ~7–11°C warmer than today.
Endocrine conditions and diabetes (with the exception of type 2 diabetes) are associated in the minds of physicians with the early part of life: many thyroid disorders, especially primary hypothyroidism and Graves’ disease, present in people in their teens, 20s, and 30s. Pituitary tumors have usually been diagnosed in younger people, as a cardinal presenting symptom is menstrual abnormalities, especially amenorrhea.
Writing about the perfect fifths that begin the first movement of Beethoven's Ninth Symphony, Donald Francis Tovey made the following observation:
Half the musical miseducation in the world comes from people who know that the Ninth Symphony begins on the dominant of D minor, when the fact is that its opening bare fifth may mean anything within D major, D minor, A major, A minor, E major, E minor, C sharp minor, G major, C major, and F major … A true analysis takes the standpoint of a listener who knows nothing beforehand, but hears and remembers everything.
The Allegretto from Beethoven's Symphony no. 7 in A Major, op. 92 (1811–12), remains one of his most popular works—an instantaneous “hit” ever since its first public performance in Vienna's University Aula on December 8, 1813, evidenced by the audience's demand for an immediate encore. The same reaction greeted the Allegretto at its second performance, an event that took place one week later. The reasons for this movement's popularity are, it would seem, self-evident. To begin with, it is relatively short, clocking in at anywhere from approximately seven to ten minutes, depending on what tempo is chosen by the conductor. Its brevity alone is an especially interesting feature given the immense size of the movement that precedes it and those that follow. Its A-minor modality, beginning with a simple, but oddly unsettling, second-inversion chord in the winds, is followed by a staccato theme in the lower strings, with a rhythmic profile comprising dactyls and spondees. Together these create a hypnotic effect. The legato counter-theme, first introduced in measure 27 in the cellos, adds an attractive new element of seductive sensuality and exoticism, created in part by its Schleifer (grace-note slides) and the subtle chromatic inflections in the counter-theme's second half. Finally, the two contrasting episodes in A major bring a welcome contrasting element of lyricism, calm, and warmth. The unveiling of its opening theme with its monotone repeated notes on the dominant of the central tonality of A minor (E), unfolds as if to suggest that we are experiencing a theme and variations form. The movement's macrostructure ultimately presents itself as a five-part rondo, although it deviates slightly from the strict definition of the form.
Administration of antimicrobials to patients with asymptomatic bacteriuria (ASB) is a common error that can lead to worse outcomes. However, controlled analyses quantifying the commonality and impact of this practice are lacking. We analyzed the independent predictors for antimicrobials misuse in ASB and quantified the impact of this practice on clinical outcomes.
Retrospective case-control and cohort analyses for calendar year 2017.
Tertiary-care, university-affiliated medical center.
The study included adult (>18 years) patients with positive urine culture. Pregnant women, renal transplant recipients, and patients who underwent urologic procedures were excluded.
ASB was determined according to US Centers for Disease Control and Prevention (CDC) criteria. Multivariable logistic regression models were constructed to analyze predictors and outcomes associated with antimicrobial use for patients with ASB.
The study included 1,530 patient-unique positive urine cultures. Among these patients, 610 patients (40%) were determined to have ASB. Of the 696 isolates, 219 (36%) were multidrug-resistant organisms (MDROs). Also, 178 (29%) patients received antimicrobials specifically due to the ASB. Independent predictors for improper administration of antimicrobials were dependent functional status (adjusted odds ratio [aOR], 2.3; 95% CI, 1.4–3.6) and male sex (aOR, 2; 95% CI, 1.25–2.6). Use of antimicrobials was independently associated with re-hospitalizations (aOR, 1.7; 95% CI, 1.1–2.6) and later, acute Clostridioides difficile infections (CDI) in the following 90 days (aOR, 4.5; 95% CI, 2–10.6).
ASB is a common condition, frequently resulting from an MDRO. Male sex and poor functional status were independent predictors for mistreatment, and this practice was independently associated with rehospitalizations and CDI in the following 90 days.
Let K be a field of characteristic zero. In this paper, we study the polynomial identities of representations of Lie algebras, also called weak identities, or identities of pairs. These identities are determined by pairs of the form (A, L) where A is an associative enveloping algebra for the Lie algebra L. Then a weak identity of (A, L) (or an identity for the representation of L associated to A) is an associative polynomial which vanishes when evaluated on elements of L⊆ A. One of the most influential results in the area of PI algebras was the theory developed by Kemer. A crucial role in it was played by the construction of the Grassmann envelope of an associative algebra and the close relation of the identities of the algebra and its Grassmann envelope. Here we consider varieties of pairs. We prove that under some restrictions one can develop a theory similar to that of Kemer's in the study of identities of representations of Lie algebras. As a consequence, we establish that in the case when K is algebraically closed, if a variety of pairs does not contain pairs corresponding to representations of sl2(K), and if the variety is generated by a pair where the associative algebra is PI then it is soluble. As another consequence of the methods used to obtain the above result, and applying ideas from papers by Giambruno and Zaicev, we were able to construct a pair (A, L) such that its PI exponent (if it exists) cannot be an integer. We recall that the PI exponent exists and is an integer whenever A is an associative (a theorem by Giambruno and Zaicev), or a finite-dimensional Lie algebra (Zaicev). Gordienko also proved that the PI exponent exists and is an integer for finite-dimensional representations of Lie algebras.
Field studies were conducted to determine sweetpotato tolerance to and weed control from management systems that included linuron. Treatments included flumioxazin preplant (107 g ai ha−1) followed by (fb) S-metolachlor (800 g ai ha−1), oryzalin (840 g ai ha−1), or linuron (280, 420, 560, 700, and 840 g ai ha−1) alone or mixed with S-metolachlor or oryzalin applied 7 d after transplanting. Weeds did not emerge before the treatment applications. Two of the four field studies were maintained weed-free throughout the season to evaluate sweetpotato tolerance without weed interference. The herbicide program with the greatest sweetpotato yield was flumioxazin fb S-metolachlor. Mixing linuron with S-metolachlor did not improve Palmer amaranth management and decreased marketable yield by up to 28% compared with flumioxazin fb S-metolachlor. Thus, linuron should not be applied POST in sweetpotato if Palmer amaranth has not emerged at the time of application.
In 1960, the Thomas Jefferson Center of the University of Virginia applied for a “massive” grant from the Ford Foundation. Although Buchanan, Nutter, and Coase had all received grants from Ford, it turned down their proposal because of the Center’s unified “point of view.” The chapter examines correspondence and private discussions of the events. Following the submission of their proposal, Buchanan, Nutter, and then-President of UVA Edgar Shannon met with representatives of the Ford Foundation, Tom Carroll and Kermit Gordon. Buchanan concluded that the “reaction of the Ford representatives must be considered to have been almost wholly negative.” The crux of the matter, in Gordon’s assessment, was the TJC’s supposed “single” and dogmatic “point of view,” an ideological perspective purportedly in line with early 1960s Chicago-style economics. Buchanan and his colleagues attempted to dispel this conclusion, arguing that the program focused on market activity as it reflected social consensus. Coase was particularly incensed by allegations of dogmatic ideological narrowness since he had close ties to the socialist Fabian Society.