Glufosinate resistance in Palmer amaranth (Amaranthus palmeri S. Watson) was recently detected in three accessions from Arkansas, USA. Amaranthus palmeri is the first and only broadleaf weed species resistant to this herbicide, and the resistance mechanism is still unclear. A previous study characterized the glufosinate resistance level in the accessions from Arkansas. A highly glufosinate-resistant accession was further used to investigate the mechanism conferring glufosinate resistance in A. palmeri. Experiments were designed to sequence the herbicide target enzyme cytosolic and chloroplastic glutamine synthetase isoforms (GS1 and GS2, respectively) and quantify copy number and expression. Absorption, translocation, and metabolism of glufosinate using the 14C-labeled herbicide were also evaluated in the resistant and susceptible accessions. The glufosinate-resistant accession had an increase in copy number and expression of GS2 compared with susceptible plants. All accessions showed only one GS1 copy and no differences in expression. No mutations were identified in GS1 or GS2. Absorption (54% to 60%) and metabolism (13% to 21%) were not different between the glufosinate-resistant and glufosinate-susceptible accessions. Most residues of glufosinate (94% to 98%) were present in the treated leaf. Glufosinate translocation to tissues above the treated leaf and in the roots was not different among accessions. However, glufosinate translocation to tissues below the treated leaf (not including roots) was greater in the resistant A. palmeri (2%) compared with the susceptible (less than 1%) accessions. The findings of this paper strongly indicate that gene amplification and increased expression of the chloroplastic glutamine synthetase enzyme are the mechanisms conferring glufosinate resistance in the A. palmeri accession investigated. Thus far, no additional resistance mechanism was observed, but further investigations are ongoing.

Background: Aerosol-generating procedures (AGPs) performed on COVID-19–positive patients raise concerns about the dissemination of SARS-CoV-2 via aerosols and droplets. Infectious aerosols and droplets generated by SARS-CoV-2–positive patient AGPs or through direct COVID-19 patient coughing or exhalation could potentially contaminate surfaces, leading to the indirect spread of SARS-CoV-2 via fomites within the emergency department (ED). We sampled surfaces of ED patient rooms occupied by known SARS-CoV-2–positive patients or patients under investigation for COVID-19 and undergoing an AGP to determine the frequency of room contamination with SARS-CoV-2 RNA. Methods: Swabs were collected from 5 room surfaces in the ED following AGPs performed on patients under investigation for COVID-19 or positive for SARS-CoV-2. High- and low-touch surfaces 6 feet (2 m) from the patient (door handle and return vent, respectively) and reusable medical equipment were swabbed. Swabs were tested for SARS-CoV-2 RNA by RT-qPCR; positive samples were cultured in Vero E6 cells. Patient COVID-19 results were confirmed through the electronic medical record. Results: In total, 203 rooms were sampled: 43 SARS-CoV-2–positive patients with an AGP, 44 SARS-CoV-2–positive patients who did not have an AGP, and 116 SARS-CoV-2–negative patients with an AGP, for a total of 1,015 swabs. Overall, SARS-CoV-2 RNA was detected on 36 (3.5%) surfaces from 29 rooms (14.3%) (Table 1). RNA contamination was detected more frequently in rooms occupied by SARS-CoV-2–positive patients who did not have an AGP than rooms occupied by COVID-19 patients (30% vs 14%). SARS-CoV-2 RNA was also detected in rooms occupied by SARS-CoV-2–negative patients undergoing an AGP (9%). SARS-CoV-2 RNA was most frequently detected on air vents (n = 15), bedrails (n = 10), equipment and vital signs monitors (n = 4 each), and door handles (n = 3). One bedrail was positive by culture and confirmed by an RT-qPCR cycle threshold reduction from >40 to 13. Conclusions: We detected SARS-CoV-2 RNA contamination on room surfaces in the ED, regardless of patient AGP or COVID-19 status; however, RNA contamination of room surfaces was most common in rooms occupied by SARS-CoV-2–positive patients who did not have an AGP, which may be attributable to stage of disease and viral shedding. SARS-CoV-2 RNA contamination was also present in rooms where APGs were performed on SARS-CoV-2–negative patients, suggesting carryover from previous patients. SARS-CoV-2 RNA was found most often on room air-return vents, further emphasizing the importance of aerosols in the spread of SARS-CoV-2.

Funding: None

Disclosures: None

This study documents the COVID-19 disease-control measures enacted in rural China and examines the economic and social impacts of these measures. We conducted two rounds of surveys with 726 randomly selected village informants across seven provinces. Strict disease-control measures have been universally enforced and appear to have been successful in limiting disease transmission in rural communities. The infection rate in our sample was 0.001 per cent, a rate that is near the national average outside of Hubei province. None of the villages reported any COVID-19-related deaths. For a full month during the quarantine, the rate of employment of rural workers was essentially zero. Even after the quarantine measures were lifted, nearly 70 per cent of the villagers still were unable to work owing to workplace closures. Although action has been taken to mitigate the potential negative effects, these disease-control measures might have accelerated the inequality between rural and urban households in China.

To achieve the elimination of the hepatitis C virus (HCV), sustained and sufficient levels of HCV testing is critical. The purpose of this study was to assess trends in testing and evaluate the effectiveness of strategies to diagnose people living with HCV. Data were from 12 primary care clinics in Victoria, Australia, that provide targeted services to people who inject drugs (PWID), alongside general health care. This ecological study spanned 2009–2019 and included analyses of trends in annual numbers of HCV antibody tests among individuals with no previous positive HCV antibody test recorded and annual test yield (positive HCV antibody tests/all HCV antibody tests). Generalised linear models estimated the association between count outcomes (HCV antibody tests and positive HCV antibody tests) and time, and χ2 test assessed the trend in test yield. A total of 44 889 HCV antibody tests were conducted 2009–2019; test numbers increased 6% annually on average [95% confidence interval (CI) 4–9]. Test yield declined from 2009 (21%) to 2019 (9%) (χ2P = <0.01). In more recent years (2013–2019) annual test yield remained relatively stable. Modest increases in HCV antibody testing and stable but high test yield within clinics delivering services to PWID highlights testing strategies are resulting in people are being diagnosed however further increases in the testing of people at risk of HCV or living with HCV may be needed to reach Australia's HCV elimination goals.

BASF Corp. has developed p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor–resistant cotton and soybean that will allow growers to use isoxaflutole in future weed management programs. In 2019 and 2020, a multi-state non-crop research project was conducted to examine weed control following isoxaflutole applied preemergence alone and with several tank-mix partners at high and low labeled rates. At 28 d after treatment (DAT), Palmer amaranth was controlled ≥95% at six of seven locations with isoxaflutole plus the high rate of diuron or fluridone. These same combinations provided the greatest control 42 DAT at four of seven locations. Where large crabgrass was present, isoxaflutole plus the high rate of diuron, fluridone, pendimethalin, or S-metolachlor or isoxaflutole plus the low rate of fluometuron controlled large crabgrass ≥95% in two of three locations 28 DAT. In two of three locations, isoxaflutole plus the high rate of pendimethalin or S-metolachlor improved large crabgrass control 42 DAT when compared to isoxaflutole alone. At 21 DAT, morningglory was controlled ≥95% at all locations with isoxaflutole plus the high rate of diuron and at three of four locations with isoxaflutole plus the high rate of fluometuron. At 42 DAT at all locations, isoxaflutole plus diuron or fluridone and isoxaflutole plus the high rate of fluometuron improved morningglory control compared to isoxaflutole alone. These results suggest that isoxaflutole applied preemergence alone or in tank mixture is efficacious on a number of cross-spectrum annual weeds in cotton, and extended weed control may be achieved when isoxaflutole is tank-mixed with several soil-residual herbicides.

This article addresses three related questions. Does voicing a political ideology in class make a professor less appealing to students? Does voicing an ideology in class make a professor less appealing to students with opposing views? Does the intensity of professors’ ideology affect their appeal? We conducted survey experiments in two public national universities to provide evidence of the extent to which students may tolerate or even prefer that professors share their political views and under which conditions these preferences may vary. Results from the experiments indicate that expressing a political opinion did not make a professor less appealing to students—and, in fact, made the professor more appealing to some students—but the perception that a professor’s ideology is particularly intense makes the class much less favorable for students with opposing views. Students are indifferent between moderately political and nonpolitical professors.