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Targeting the glutamatergic system is posited as a potentially novel therapeutic strategy for psychotic disorders. While studies in subjects indicate that antipsychotic medication reduces brain glutamatergic measures, they were unable to disambiguate clinical changes from drug effects.
Aims
To address this, we investigated the effects of a dopamine D2 receptor partial agonist (aripiprazole) and a dopamine D2 receptor antagonist (amisulpride) on glutamatergic metabolites in the anterior cingulate cortex (ACC), striatum and thalamus in healthy controls.
Method
A double-blind, within-subject, cross-over, placebo-controlled study design with two arms (n = 25 per arm) was conducted. Healthy volunteers received either aripiprazole (up to 10 mg/day) for 7 days or amisulpride (up to 400 mg/day) and a corresponding period of placebo treatment in a pseudo-randomised order. Magnetic resonance spectroscopy (1H-MRS) was used to measure glutamatergic metabolite levels and was carried out at three different time points: baseline, after 1 week of drug and after 1 week of placebo. Values were analysed as a combined measure across the ACC, striatum and thalamus.
Results
Aripiprazole significantly increased glutamate + glutamine (Glx) levels compared with placebo (β = 0.55, 95% CI [0.15, 0.95], P = 0.007). At baseline, the mean Glx level was 8.14 institutional units (s.d. = 2.15); following aripiprazole treatment, the mean Glx level was 8.16 institutional units (s.d. = 2.40) compared with 7.61 institutional units (s.d. = 2.36) for placebo. This effect remained significant after adjusting for plasma parent and active metabolite drug levels. There was an observed increase with amisulpride that did not reach statistical significance.
Conclusions
One week of aripiprazole administration in healthy participants altered brain Glx levels as compared with placebo administration. These findings provide novel insights into the relationship between antipsychotic treatment and brain metabolites in a healthy participant cohort.
Patients with posttraumatic stress disorder (PTSD) exhibit smaller regional brain volumes in commonly reported regions including the amygdala and hippocampus, regions associated with fear and memory processing. In the current study, we have conducted a voxel-based morphometry (VBM) meta-analysis using whole-brain statistical maps with neuroimaging data from the ENIGMA-PGC PTSD working group.
Methods
T1-weighted structural neuroimaging scans from 36 cohorts (PTSD n = 1309; controls n = 2198) were processed using a standardized VBM pipeline (ENIGMA-VBM tool). We meta-analyzed the resulting statistical maps for voxel-wise differences in gray matter (GM) and white matter (WM) volumes between PTSD patients and controls, performed subgroup analyses considering the trauma exposure of the controls, and examined associations between regional brain volumes and clinical variables including PTSD (CAPS-4/5, PCL-5) and depression severity (BDI-II, PHQ-9).
Results
PTSD patients exhibited smaller GM volumes across the frontal and temporal lobes, and cerebellum, with the most significant effect in the left cerebellum (Hedges’ g = 0.22, pcorrected = .001), and smaller cerebellar WM volume (peak Hedges’ g = 0.14, pcorrected = .008). We observed similar regional differences when comparing patients to trauma-exposed controls, suggesting these structural abnormalities may be specific to PTSD. Regression analyses revealed PTSD severity was negatively associated with GM volumes within the cerebellum (pcorrected = .003), while depression severity was negatively associated with GM volumes within the cerebellum and superior frontal gyrus in patients (pcorrected = .001).
Conclusions
PTSD patients exhibited widespread, regional differences in brain volumes where greater regional deficits appeared to reflect more severe symptoms. Our findings add to the growing literature implicating the cerebellum in PTSD psychopathology.
Vaso-occlusive episodes (VOE) are the most common complication resulting from sickle cell disease (SCD) in adults. VOEs are caused by ischemic tissue injury as a result of occlusion of microvascular beds from abnormal sickle shaped red blood cells (RBCs). Individuals with SCD display a host of complications associated with micro and occasionally macro vascular occlusion, including stroke, leg ulcers, spontaneous miscarriage, and renal insufficiency. The acute pain crisis is the most common reason patients with SCD seek medical care in emergency departments (EDs). Due to the recurrent nature of acute pain crises, possible inadequate knowledge of health care providers about the disease, and the intensity of treatment needed, patients with VOEs may be undermedicated in the ED. This can lead to low patient satisfaction, low provider satisfaction, and increased cost of care. Through the use of an ED observation unit (OU) or clinical pathway, patients experiencing VOEs can be effectively managed to improve outcomes, improve satisfaction, and decrease cost of care.
Specimens of Tulaneia amabilia Runnegar and Horodyski n. gen n. sp. (previously Ernietta plateauensis Pflug) discovered by RJH in 1991 at a site in the Montgomery Mountains near Johnnie, Nevada, are described for the first time. All of the material from the original locality was from float, but its stratigraphic position within the lowest siliciclastic to dolostone interval of the lower member of the Wood Canyon Formation (LMWCF) was confirmed by subsequent discoveries. Because the upper part of the LMWCF contains Treptichnus pedum (Seilacher), the Ediacaran–Cambrian boundary has long been drawn at its first appearance. However, in the Esmeralda Member of the Deep Spring Formation in the White-Inyo Mountains, California, and at Mount Dunfee, Nevada, another Cambrian ichnofossil, ‘Plagiogmus’, which is now Psammichnites gigas arcuatus (Roedel), is found just beneath the nadir of the basal Cambrian isotope excursion (BACE). Because the nadir of the BACE excursion is older than ca. 539 Ma in Mexico, the oldest occurrences of Treptichnus pedum in the LMWCF are latest—not earliest—Fortunian in age, and there is no need to reduce the age of the eon boundary from ca. 539 to ca. 533 Ma. Tulaneia resembles Ernietta and other erniettomorphs in being composed of tubular modules with planar common surfaces, but its overall shape was tabular and unidirectional rather than sack or frond shaped. We also illustrate and briefly describe other trace and body fossils from the LMWCF and re-illustrate previously published specimens of Psammichnites gigas arcuatus in order to document its earliest occurrence in the Great Basin.
Physical health checks in primary care for people with severe mental illness ((SMI) defined as schizophrenia, bipolar disorders and non-organic psychosis) aim to reduce health inequalities. Patients who decline or are deemed unsuitable for screening are removed from the denominator used to calculate incentivisation, termed exception reporting.
Aims
To describe the prevalence of, and patient characteristics associated with, exception reporting in patients with SMI.
Method
We identified adult patients with SMI from the UK Clinical Practice Research Datalink (CPRD), registered with a general practice between 2004 and 2018. We calculated the annual prevalence of exception reporting and investigated patient characteristics associated with exception reporting, using logistic regression.
Results
Of 193 850 patients with SMI, 27.7% were exception reported from physical health checks at least once. Exception reporting owing to non-response or declining screening increased over the study period. Patients of Asian or Black ethnicity (Asian: odds ratio 0.72, 95% CI 0.65–0.80; Black: odds ratio 0.86, 95% CI 0.76–0.97; compared with White) and women (odds ratio 0.90, 95% CI 0.88–0.92) had a reduced odds of being exception reported, whereas patients diagnosed with ‘other psychoses’ (odds ratio 1.19, 95% CI 1.15–1.23; compared with bipolar disorder) had increased odds. Younger patients and those diagnosed with schizophrenia were more likely to be exception reported owing to informed dissent.
Conclusions
Exception reporting was common in people with SMI. Interventions are required to improve accessibility and uptake of physical health checks to improve physical health in people with SMI.
Bronze Age–Early Iron Age tin ingots recovered from four Mediterranean shipwrecks off the coasts of Israel and southern France can now be provenanced to tin ores in south-west Britain. These exceptionally rich and accessible ores played a fundamental role in the transition from copper to full tin-bronze metallurgy across Europe and the Mediterranean during the second millennium BC. The authors’ application of a novel combination of three independent analyses (trace element, lead and tin isotopes) to tin ores and artefacts from Western and Central Europe also provides the foundation for future analyses of the pan-continental tin trade in later periods.
Evaluate impact of COVID-19 prevention training with video-based feedback on nursing home (NH) staff safety behaviors.
Design:
Public health intervention
Setting & Participants:
Twelve NHs in Orange County, California, 6/2020-4/2022
Methods:
NHs received direct-to-staff COVID-19 prevention training and weekly feedback reports with video montages about hand hygiene, mask-wearing, and mask/face-touching. One-hour periods of recorded streaming video from common areas (breakroom, hallway, nursing station, entryway) were sampled randomly across days of the week and nursing shifts for safe behavior. Multivariable models assessed the intervention impact.
Results:
Video auditing encompassed 182,803 staff opportunities for safe behavior. Hand hygiene errors improved from first (67.0%) to last (35.7%) months of the intervention, decreasing 7.6% per month (OR = 0.92, 95% CI = 0.92–0.93, P < 0.001); masking errors improved from first (10.3 %) to last (6.6%) months of the intervention, decreasing 2.3% per month (OR = 0.98, 95% CI = 0.97–0.99, P < 0.001); face/mask touching improved from first (30.0%) to last (10.6%) months of the intervention, decreasing 2.5% per month (OR = 0.98, 95% CI = 0.97–0.98, P < 0.001). Hand hygiene errors were most common in entryways and on weekends, with similar rates across shifts. Masking errors and face/mask touching errors were most common in breakrooms, with the latter occurring most commonly during the day (7A.M.–3P.M.) shift, with similar rates across weekdays/weekends. Error reductions were seen across camera locations, days of the week, and nursing shifts, suggesting a widespread benefit within participating NHs.
Conclusion:
Direct-to-staff training with video-based feedback was temporally associated with improved hand hygiene, masking, and face/mask-touching behaviors among NH staff during the COVID-19 pandemic.
Objectives/Goals: Magnetic resonance imaging (MRI) reports are stored as unstructured text in the electronic health record (EHR), rendering the data inaccessible. Large language models (LLM) are a new tool for analyzing and generating unstructured text. We aimed to evaluate how well an LLM extracts data from MRI reports compared to manually abstracted data. Methods/Study Population: The University of California, San Francisco has deployed a HIPAA-compliant internal LLM tool utilizing GPT-4 technology and approved for PHI use. We developed a detailed prompt instructing the LLM to extract data elements from prostate MRI reports and to output the results in a structured, computer-readable format. A data pipeline was built using the OpenAI Application Programming Interface (API) to automatically extract distinct data elements from the MRI report that are important in prostate cancer care. Each prompt was executed five times and data were compared with the modal responses to determine variability of responses. Accuracy was also assessed. Results/Anticipated Results: Across 424 prostate MRI reports, GPT-4 response accuracy was consistently above 95% for most parameters. Individual field accuracies were 98.3% (96.3–99.3%) for PSA density, 97.4% (95.4–98.7%) for extracapsular extension, 98.1% (96.3–99.2%) for TNM Stage, had an overall median of 98.1% (96.3–99.2%), a mean of 97.2% (95.2–98.3%), and a range of 99.8% (98.7–100.0%) to 87.7% (84.2–90.7%). Response variability over five repeated runs ranged from 0.14% to 3.61%, differed based on the data element extracted (p Discussion/Significance of Impact: GPT-4 was highly accurate in extracting data points from prostate cancer MRI reports with low upfront programming requirements. This represents an effective tool to expedite medical data extraction for clinical and research use cases.
Decentralized research has many advantages; however, little is known about the representativeness of a source population in decentralized studies. We recruited participants aged 18-64 years from four states from June to December 2022 for a prospective cohort study to assess viral epidemiology. Our aim was to determine the association between age, gender, race/ethnicity, rurality, and socioeconomic status (SES) on study participation in a decentralized prospective cohort study.
Methods:
We consented 9,286 participants from 231,099 (4.0%) adults with the mean age of 45.6 years (±12.0). We used an electronic decentralized approach for recruitment. Consented participants were more likely to be non-Hispanic White, female, older, urban residents, have more health conditions, and possessed higher socioeconomic status (SES) compared to those non-consented.
Results:
We observed an interaction between SES and race-ethnicity on the odds of consent (P = 0.006). Specifically, SES did not affect non-Hispanic white participation rates(OR 1.24 95% CI 1.16 – 1.32] for the highest SES quartile compared to those with the lowest SES quartile) as much as it did participants combined across the other races (OR 1.73; 95% CI 1.45 – 2.98])
Conclusion:
The relationship between SES and consent rates might be disproportionately greater in historically disadvantaged groups, compared to non-Hispanic White. It suggests that instead of focusing on enrollment of specific minority groups in research, there is value in future research exploring and addressing the diversity of barriers to trials within minority groups. Our study highlights that decentralized studies need to address social determinants of health, especially in under-resourced populations.
Hallucinations are common and distressing symptoms in Parkinson’s disease (PD). Treatment response in clinical trials is measured using validated questionnaires, including the Scale for Assessment of Positive Symptoms-Hallucinations (SAPS-H) and University of Miami PD Hallucinations Questionnaire (UM-PDHQ). The minimum clinically important difference (MCID) has not been determined for either scale. This study aimed to estimate a range of MCIDs for SAPS-H and UM-PDHQ using both consensus-based and statistical approaches.
Methods
A Delphi survey was used to seek opinions of researchers, clinicians, and people with lived experience. We defined consensus as agreement ≥75%. Statistical approaches used blinded data from the first 100 PD participants in the Trial for Ondansetron as Parkinson’s Hallucinations Treatment (TOP HAT, NCT04167813). The distribution-based approach defined the MCID as 0.5 of the standard deviation of change in scores from baseline at 12 weeks. The anchor-based approach defined the MCID as the average change in scores corresponding to a 1-point improvement in clinical global impression-severity scale (CGI-S).
Results
Fifty-one researchers and clinicians contributed to three rounds of the Delphi survey and reached consensus that the MCID was 2 points on both scales. Sixteen experts with lived experience reached the same consensus. Distribution-defined MCIDs were 2.6 points for SAPS-H and 1.3 points for UM-PDHQ, whereas anchor-based MCIDs were 2.1 and 1.3 points, respectively.
Conclusions
We used triangulation from multiple methodologies to derive the range of MCID estimates for the two rating scales, which was between 2 and 2.7 points for SAPS-H and 1.3 and 2 points for UM-PDHQ.
Sudden cardiac death is a significant concern among patients with congenital heart disease (CHD). We assessed the risk of remote sudden cardiac death after congenital heart surgery.
Methods:
Patients undergoing congenital heart surgery before 21 years of age between 1982 and 2003 in the Pediatric Cardiac Care Consortium registry were linked to National Death Index data through 2019. Sudden cardiac death was defined as death associated with a cardiac arrest or ventricular fibrillation diagnosis code. Standardised mortality ratios relative to the general population were calculated using Centers for Disease Control and Prevention data.
Results:
Among 30,566 patients discharged after their initial surgery, 2,718 deaths occurred over a median period of 23 years (IQR 19–27). Of 463 (17%) sudden cardiac deaths, the median age was 1.7 years (IQR 0.5–16.5). The mean incidence was 7 per 10,000 person-years (95% CI: 0.64–0.77), ranging from 2.7 for left-to-right shunt lesions to 37 for single-ventricle physiology. Cardiac comorbidities including heart failure (13.6%) and arrhythmias (7.1%) were more frequent among sudden cardiac death patients. Standard mortality ratios for sudden cardiac death were elevated across all CHD types, ranging from 8.0 (95% CI: 6.3–9.6) for left-to-right shunts to 107.7 (95% CI: 88.9–126.5) for single-ventricle physiology.
Conclusion:
Sudden cardiac death risk is higher post-congenital heart surgery compared to the general population. Even patients with mild CHD are at risk, highlighting the need for long-term follow-up for all patients. Heart failure and arrhythmia prevalence suggest potential therapeutic targets to reduce sudden cardiac death risk.
Antibiograms monitor antibiotic resistance trends and help guide empiric antibiotic treatment. A statewide pediatric antibiogram can help inform stewardship efforts.
Methods:
Annual pediatric antibiograms for the five children’s hospitals in Georgia from 2014–2023 were collected. All sites used the Clinical and Laboratory Standards Institute guidelines for antibiogram development. Antibiogram data were combined, and the most common bacteria were included: Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae complex and Pseudomonas aeruginosa. Interhospital differences were compared for methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), E. coli and K. pneumoniae. The combined data from 2014 and 2023 were compared to demonstrate antibiotic susceptibility changes over time.
Results:
Data in 2023 for MSSA and MRSA showed clindamycin susceptibility was 78% and 82%, respectively. S. pneumoniae susceptibility to amoxicillin/clavulanate was 96%. E. faecalis resistance to ampicillin and vancomycin was rare. For all included gram-negative bacteria, susceptibility remained high to 3rd generation cephalosporins (90%–92%) and meropenem (95%–99%). From 2014 to 2023, the rate of MRSA decreased from 49% to 33.5%. S. pneumoniae susceptibility to amoxicillin/clavulanate and clindamycin significantly increased. For E. coli, there was a significant decrease in susceptibility for cefazolin (90% to 84%), ceftriaxone (95% to 92%), and meropenem (100% to 99%). There were nonsignificant decreases in susceptibility for K. pneumoniae.
Conclusion:
Over the past 10 years, MRSA rates decreased, S. pneumoniae antibiotic susceptibility increased, and gram-negative bacilli susceptibility was stable to slightly decreased. Georgia antibiogram data support the recommended antibiotic treatment for common pediatric infections.
Vaccines have revolutionised the field of medicine, eradicating and controlling many diseases. Recent pandemic vaccine successes have highlighted the accelerated pace of vaccine development and deployment. Leveraging this momentum, attention has shifted to cancer vaccines and personalised cancer vaccines, aimed at targeting individual tumour-specific abnormalities. The UK, now regarded for its vaccine capabilities, is an ideal nation for pioneering cancer vaccine trials. This article convened experts to share insights and approaches to navigate the challenges of cancer vaccine development with personalised or precision cancer vaccines, as well as fixed vaccines. Emphasising partnership and proactive strategies, this article outlines the ambition to harness national and local system capabilities in the UK; to work in collaboration with potential pharmaceutic partners; and to seize the opportunity to deliver the pace for rapid advances in cancer vaccine technology.
Coronavirus disease-2019 precipitated the rapid deployment of novel therapeutics, which led to operational and logistical challenges for healthcare organizations. Four health systems participated in a qualitative study to abstract lessons learned, challenges, and promising practices from implementing neutralizing monoclonal antibody (nMAb) treatment programs. Lessons are summarized under three themes that serve as critical building blocks for health systems to rapidly deploy novel therapeutics during a pandemic: (1) clinical workflows, (2) data infrastructure and platforms, and (3) governance and policy. Health systems must be sufficiently agile to quickly scale programs and resources in times of uncertainty. Real-time monitoring of programs, policies, and processes can help support better planning and improve program effectiveness. The lessons and promising practices shared in this study can be applied by health systems for distribution of novel therapeutics beyond nMAbs and toward future pandemics and public health emergencies.
In the context of climate change, the impacts of extreme weather events are increasingly recognised as a significant threat to mental health in the UK. As clinicians and researchers with an interest in mental health, we have a collective responsibility to help understand and mitigate these impacts. To achieve this, however, it is vital to have an appreciation of the relevant policy and regulatory frameworks. In this feature article, a collaboration amongst mental health and policy experts, we provide an overview of the integration of mental health within current climate policies and regulations in the UK, including gaps and opportunities. We argue that current policy and regulatory frameworks are lacking in coverage, ambition, detail and implementation, as increases in weather extremes and their negative impacts on mental health outpace action. For example, across current national and local climate policies, there is almost no reference to the impacts of extreme weather events on mental health. Whilst alarming, this provides scope for future research to fill evidence gaps and inform policy and regulatory change. We call for mental health and policy experts to work together to improve our understanding of underlying mechanisms and develop practical interventions, helping to bring mental health within climate policy and regulatory frameworks.
Edited by
David M. Greer, Boston University School of Medicine and Boston Medical Center,Neha S. Dangayach, Icahn School of Medicine at Mount Sinai and Mount Sinai Health System
Mortality rates for children in the pediatric intensive care unit (PICU) have decreased 5-fold from 1-in-5 [1] to 1-in-25 [2] cases over the past few decades. Despite improvements in rates of survival after critical illness, 1-in-5 children who require life support in the PICU for an acute illness has a new morbidity up to 3 years after discharge.[2,3] That translates to new functional, cognitive, and/or neurological morbidity in 5–10% of PICU survivors.[2,3] Also, for the parents of these children, the child’s critical illness may become a chronic condition that leads to ongoing emotional stress for the whole family with significant psychological and social impact.[4]
There are several important distinctions between children and adults in regard to making a prognosis as a result of acute neurological injury – henceforth called neuroprognostication. Foremost, during the initial presentation of acute neurological illness, event, or trauma, there is a partnership between clinicians and parents, and the communication of likelihood of possible death versus survival.
Machine learning (ML) has developed classifiers differentiating patient groups despite concerns regarding diagnostic reliability. An alternative strategy, used here, is to develop a functional classifier (hyperplane) (e.g. distinguishing the neural responses to received reward v. received punishment in typically developing (TD) adolescents) and then determine the functional integrity of the response (reward response distance from the hyperplane) in adolescents with externalizing and internalizing conditions and its associations with symptom clusters.
Methods
Two hundred and ninety nine adolescents (mean age = 15.07 ± 2.30 years, 117 females) were divided into three groups: a training sample of TD adolescents where the Support Vector Machine (SVM) algorithm was applied (N = 65; 32 females), and two test groups– an independent sample of TD adolescents (N = 39; 14 females) and adolescents with a psychiatric diagnosis (major depressive disorder (MDD), generalized anxiety disorder (GAD), attention deficit hyperactivity disorder (ADHD) & conduct disorder (CD); N = 195, 71 females).
Results
SVM ML analysis identified a hyperplane with accuracy = 80.77%, sensitivity = 78.38% and specificity = 88.99% that implicated feature neural regions associated with reward v. punishment (e.g. nucleus accumbens v. anterior insula cortices). Adolescents with externalizing diagnoses were significantly less likely to show a normative and significantly more likely to show a deficient reward response than the TD samples. Deficient reward response was associated with elevated CD, MDD, and ADHD symptoms.
Conclusions
Distinguishing the response to reward relative to punishment in TD adolescents via ML indicated notable disruptions in this response in patients with CD and ADHD and associations between reward responsiveness and CD, MDD, and ADHD symptom severity.
Weeds belonging to the Amaranthus family are most problematic for soybean producers. With Palmer amaranth evolving resistance to multiple herbicides labeled for use in soybean, producers seek new sites of action to integrate into season-long herbicide programs. Bayer CropScience plans to launch a Convintro™ brand of herbicides, one being a premixture that will include diflufenican (categorized as a Group 12 herbicide by the Weed Science Society of America [WSSA]), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15), for use preemergence in soybean. Research trials were conducted in Fayetteville and Keiser, AR, and Holt, MI, in 2022 and 2023, to evaluate the premixture in a season-long program in a dicamba-resistant soybean system. A 0.17:0.35:0.48 ratio of a premixture of diflufenican:metribuzin:flufenacet (DFF-containing premixture) was applied preemergence with different combinations of glyphosate, glufosinate, dicamba, and acetochlor at 28 (early postemergence) and 42 (late postermergence) days after planting (DAP). At the early postemergence timing, the DFF-containing premixture provided >90% control of Palmer amaranth and prickly sida. However, common ragweed, common lambsquarters, morningglory ssp., and annual grass control was ≤80% at this timing. When the late postemergence applications occurred, treatments that had already received an early postemergence application controlled prickly sida, morningglory ssp., Palmer amaranth, and annual grasses to a greater extent than those that had not, indicating the preemergence application of the DFF-containing premixture was not sufficient to provide control of the weed spectrum through 42 DAP. By 70 DAP, all programs provided ≥93% control of all weeds evaluated. Herbicide programs that included the DFF-containing premixture preemergence followed by (fb) EPOST fb LPOST common ragweed, common lambsquarters, morningglory ssp., and annual grasses to a greater than the one-pass postemergence systems. In addition, all herbicide programs evaluated in this study reduced Palmer amaranth seed production by >99%. However, producers who plan to use the DFF-containing premixture may need two postemergence herbicide applications to obtain high levels of weed control throughout the growing season.
With Palmer amaranth and waterhemp evolving resistance to nine and six different sites of action (SOAs) globally, soybean producers continue to search for new options to control these problematic weeds. Bayer CropScience has announced its intentions to launch a Convintro™ brand of herbicides, one being a three-way premixture for preemergence use in soybean. The premixture will contain diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15), adding a new SOA for soybean producers throughout the United States. With the anticipated launch of the premixture, research is needed to evaluate the length of residual control provided by the new herbicide. Research trials were conducted in Fayetteville and Keiser, AR, and Morrice, MI, in 2022 and 2023. A 0.17:0.35:0.48 ratio of a diflufenican:metribuzin:flufenacet (DFF)-containing premixture was applied alone and in combination with additional metribuzin and dicamba. Also, metribuzin, acetochlor, a S-metolachlor:metribuzin premixture, and a flumioxazin:pyroxasulfone:metribuzin premixture were applied preemergence. The DFF-containing premixture was more effective in reducing Palmer amaranth/waterhemp emergence than acetochlor in four of six trials at 28 d after treatment (DAT). Palmer amaranth and waterhemp densities in plots treated with the DFF-containing premixture exhibited similar results to plots treated with the S-metolachlor:metribuzin premixture and the flumioxazin:pyroxasulfone:metribuzin premixture at 28 DAT. By 56 DAT, Palmer amaranth and waterhemp densities were comparable or superior in plots with the DFF-containing premixture than in those treated with acetochlor and metribuzin, and the S-metolachlor:metribuzin premixture at five of six sites. The addition of dicamba or metribuzin to the DFF-containing premixture did not reduce Palmer amaranth or waterhemp density compared to the DFF-containing premixture at 28 or 56 DAT. Overall, the DFF-containing premixture generally provided greater or comparable control over several standard herbicides, providing growers a new product for preemergence control of Amaranthus species in soybean fields.
Bayer Crop Science anticipates launching several premixtures for use in soybean, targeted at control of Palmer amaranth. One of the premixtures will contain diflufenican (Weed Science Society of America [WSSA] Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15) (DFF-containing premixture), offering an alternative site of action for soybean producers. Field experiments were conducted in Arkansas and Michigan to evaluate application timings of the DFF-containing premixture for soybean tolerance and weed control and possible cultivar tolerance differences to diflufenican and the DFF-containing premixture. Soybean injury from the 1X and 2X rates of the DFF-containing premixture ranged from 0% to 60% 14 d after planting (DAP), with injury increasing the closer the herbicide was applied to soybean emergence. Excluding the 2X rate applied 3 DAP in Arkansas in 2023, soybean injury was <20% regardless of location, site-year, application timing, and rate. For weed control experiments, only a 1X rate of the DFF-containing premixture was applied at the various application timings. Control of five weed species, encompassing broadleafs and grasses, ranged from 81% to 98%, regardless of application timing, by 28 DAP. By 42 DAP, weed control ranged from 71% to 97%, with the 14-d preplant application timing typically being the least effective. The DFF-containing premixture and diflufenican alone were applied PRE at 1X and 2X rates for the soybean cultivar study. Soybean metribuzin sensitivity did not affect the degree of crop response, even in a high-pH soil, and injury to soybean never exceeded 20%. Overall, the DFF-containing premixture will be a tool that soybean producers can integrate into a season-long herbicide program for use across the United States regardless of soybean cultivar.