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Hairy fleabane and horseweed are pervasive weed species in agriculture. Glyphosate-resistant (GR) and glyphosate/paraquat–resistant (GPR) biotypes challenge current management strategies. These GR and GPR biotypes have non–target site resistance, which can confer resistance to herbicides with different sites of action (SOAs). This study’s objective was to characterize the response of GR, GPR, and glyphosate/paraquat–susceptible (GPS) biotypes of both weed species to herbicides with a different SOA. Whole-plant dose–response bioassays indicated a similar response among tested biotypes of both weed species to rimsulfuron, dicamba, hexazinone, glufosinate, flumioxazin, saflufenacil, or mesotrione. The hairy fleabane GR and GPR biotypes were 2.7- and 2.9-fold resistant to 2,4-D relative to the GPS biotype (GR50 766.7 g ai ha–1), confirming 2,4-D resistance in hairy fleabane for the first time in California. The GR and GPR biotypes were not cross-resistant to dicamba. No differences in response to 2,4-D were observed among horseweed biotypes with a GR50 ranging from 150.2 to 277.4 g ai ha–1. The GPR biotypes of both species were cross-resistant to diquat, with a 44.0-fold resistance in hairy fleabane (GR50 863.7 g ai ha–1) and 15.6-fold resistance in horseweed (GR50 563.1 g ai ha–1). The confirmation of multiple resistances to glyphosate, paraquat, and 2,4-D in hairy fleabane curtails herbicide SOA alternatives and jeopardizes resistance management strategies based on herbicide rotation and tank mixtures, underscoring the critical need for nonchemical weed control alternatives.
Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed-shatter phenology in 13 economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to 4 wk after physiological maturity at multiple sites spread across 14 states in the southern, northern, and mid-Atlantic United States. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate increased at northern latitudes. Amaranthus spp. seed shatter was low (0% to 2%), whereas shatter varied widely in common ragweed (Ambrosia artemisiifolia L.) (2% to 90%) over the weeks following soybean physiological maturity. Overall, the broadleaf species studied shattered less than 10% of their seeds by soybean harvest. Our results suggest that some of the broadleaf species with greater seed retention rates in the weeks following soybean physiological maturity may be good candidates for HWSC.
Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to 4 wk after maturity at multiple sites spread across 11 states in the southern, northern, and mid-Atlantic United States. From soybean maturity to 4 wk after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased moving north through the states. At soybean maturity, the percent of seed shatter ranged from 1% to 70%. That range had shifted to 5% to 100% (mean: 42%) by 25 d after soybean maturity. There were considerable differences in seed-shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output during certain years.
Field studies were conducted in 2018 and 2019 in Arkansas, Indiana, Illinois, Missouri, and Tennessee to determine if cover-crop residue interfered with herbicides that provide residual control of Palmer amaranth and waterhemp in no-till soybean. The experiments were established in the fall with planting of cover crops (cereal rye + hairy vetch). Herbicide treatments consisted of a nontreated or no residual, acetochlor, dimethenamid-P, flumioxazin, pyroxasulfone + flumioxazin, pendimethalin, metribuzin, pyroxasulfone, and S-metolachlor. Palmer amaranth took 18 d and waterhemp took 24 d in the cover crop–alone (nontreated) treatment to reach a height of 10 cm. Compared with this treatment, all herbicides except metribuzin increased the number of days until 10-cm Palmer amaranth was present. Flumioxazin applied alone or in a mixture with pyroxasulfone were the best at delaying Palmer amaranth growing to a height of 10 cm (35 d and 33 d, respectively). The herbicides that resulted in the lowest Palmer amaranth density (1.5 to 4 times less) integrated with a cover crop were pyroxasulfone + flumioxazin, flumioxazin, pyroxasulfone, and acetochlor. Those four herbicide treatments also delayed Palmer amaranth emergence for the longest period (27 to 34 d). Waterhemp density was 7 to 14 times less with acetochlor than all the other herbicides present. Yield differences were observed for locations with waterhemp. This research supports previous research indicating that utilizing soil-residual herbicides along with cover crops improves control of Palmer amaranth and/or waterhemp.
A 65-year-old male with a history of hypertension presents to the emergency department (ED) with new onset of non-traumatic back pain. The patient is investigated for life-threatening diagnoses and screened for “red flag symptoms,” including fever, neurologic abnormalities, bowel/bladder symptoms, and a history of injectiondrug use (IVDU). The patient is treated symptomatically and discharged home but represents to the ED three additional times, each time with new and progressive symptoms. At the time of admission, he is unable to ambulate, has perineal anesthesia, and 500 cc of urinary retention. Whole spine magnetic resonance imaging (MRI) confirms a thoracic spinal epidural abscess. This case, and many like it, prompts the questions: when should emergency physicians consider the diagnosis of a spinal epidural abscess, and what is the appropriate evaluation of these patients in the ED? (Figure 1).
The Cognitive Abilities Screening Instrument (CASI) is a screening test of global cognitive function used in research and clinical settings. However, the CASI was developed using face validity and has not been investigated via empirical tests such as factor analyses. Thus, we aimed to develop and test a parsimonious conceptualization of the CASI rooted in cognitive aging literature reflective of crystallized and fluid abilities.
Secondary data analysis implementing confirmatory factor analyses where we tested the proposed two-factor solution, an alternate one-factor solution, and conducted a χ2 difference test to determine which model had a significantly better fit.
Data came from 3,491 men from the Kuakini Honolulu-Asia Aging Study.
The Cognitive Abilities Screening Instrument.
Findings demonstrated that both models fit the data; however, the two-factor model had a significantly better fit than the one-factor model. Criterion validity tests indicated that participant age was negatively associated with both factors and that education was positively associated with both factors. Further tests demonstrated that fluid abilities were significantly and negatively associated with a later-life dementia diagnosis.
We encourage investigators to use the two-factor model of the CASI as it could shed light on underlying cognitive processes, which may be more informative than using a global measure of cognition.
Vascular cognitive impairment (VCI) post-stroke is frequent but may go undetected, which highlights the need to better screen cognitive functioning following a stroke.
We examined the clinical utility of the Montreal Cognitive Assessment (MoCA) in detecting cognitive impairment against a gold-standard neuropsychological battery.
We assessed cognitive status with a comprehensive battery of neuropsychological tests in 161 individuals who were at least 3-months post-stroke. We used receiver operating characteristic (ROC) curves to identify two cut points for the MoCA to maximize sensitivity and specificity at a minimum 90% threshold. We examined the utility of the Symbol Digit Modalities Test, a processing speed measure, to determine whether this additional metric would improve classification relative to the MoCA total score alone.
Using two cut points, 27% of participants scored ≤ 23 and were classified as high probability of cognitive impairment (sensitivity 92%), and 24% of participants scored ≥ 28 and were classified as low probability of cognitive impairment (specificity 91%). The remaining 48% of participants scored from 24 to 27 and were classified as indeterminate probability of cognitive impairment. The addition of a processing speed measure improved classification for the indeterminate group by correctly identifying 65% of these individuals, for an overall classification accuracy of 79%.
The utility of the MoCA in detecting cognitive impairment post-stroke is improved when using a three-category approach. The addition of a processing speed measure provides a practical and efficient method to increase confidence in the determined outcome while minimally extending the screening routine for VCI.
Implicit memories like consumption habits and conditioned reactions to drug-related stimuli are operational in addiction and relapse. The affective startle paradigm is an attractive tool for the measurement of the incentive salience of drug-related cues. We tested whether the stronger appetitive valence of drug cues, shown in two recent startle studies in smokers, does persist after prolonged abstinence, and may thus contribute to relapse.
We examined the auditory startle reflex magnitude of mildly deprived (4-6 hours) heavy smokers (n = 24), former smokers (n = 16, mean abstinence interval 18 months), and non-smokers (n = 24) while they viewed smoking-related scenes or standardized unpleasant, neutral and pleasant control scenes from the International Affective Picture System.
As expected, non-smokers showed no appetitive reactions toward smoking-cues. In smokers, smoking-cues had both appetitive implicit (startle suppression) and explicit (ratings for valence and craving) motivational effects, resembling those of pleasant scenes and differing from neutral and unpleasant scenes. This effect was more pronounced in smokers who later relapsed after a smoking cessation program, and in smokers consuming less than 20 cigarettes per day. Former smokers, despite reporting no craving and negative reactions to smoking cues, still showed evidence of implicit appetitive valence of these cues.
Nicotine addiction results in automatic appetitive reactions to drug-cues, which does not vanish after prolonged abstinence and which may thus contribute to relapses. Heavy smoking may result in a progressive internalization of smoking habits and a decline in reactivity towards external smoking-associated cues.
Attentional bias is an important psychological mechanism that has been extensively explored within the anxiety literature and more recently in chronic pain. Cognitive behavioural models of chronic fatigue syndrome (CFS) and chronic pain suggest an overlap in the mechanisms of these two conditions. the current study investigated attentional bias towards health-threat stimuli in individuals with CFS, compared to healthy controls. the study also examined whether individuals with CFS have impaired executive attention, and how it was related to attentional bias.
Two participant groups, CFS (n = 27) and healthy control (n = 35), completed a Visual Probe Task measuring attentional bias towards health-threat stimuli (words and pictures) presented at 500ms and 1250ms, and an Attention Network Test measuring alerting, orienting and executive attention. Participants also completed a series of standard self-report measures.
When compared to the control group, the CFS group showed greater attentional bias towards threat-words, but not pictures, regardless of stimulus duration. This was not related to anxiety or depression. the CFS group was also significantly impaired on executive attention compared to the controls. Post-hoc analyses indicated that only CFS individuals with poor executive attention showed a threat-word bias when compared to controls and CFS individuals with good executive attention.
The findings from this study suggest that CFS individuals show enhanced attentional biases for health-threat stimuli, which may contribute to the perpetuation of the condition. Moreover, the attentional biases in CFS are dependent on an individual's capacity to voluntarily control their attention.
Psychological stress is associated with accelerated cellular aging and increased risk for aging-related diseases, but the underlying molecular mechanisms are unclear.
We examined the effect of stress on a DNA methylation age predictor that was shown to correlate strongly with chronological age across human tissues (Horvath 2013). Genome-wide DNA methylation was measured in peripheral blood using the 450K Illumina array in three independent cohorts: the Grady Trauma Project/GTP (N=366); a panic disorder case/control sample recruited at the Max Planck Institute of Psychiatry/MPI-P (N=318); and the Conte Center for the Psychobiology of Early-Life Trauma/Conte (N=42). Age acceleration was calculated by subtracting chronological age from age predicted by DNA methylation. Psychiatric symptomatology and stressors were assessed using standard questionnaires.
DNA methylation age strongly correlated with chronological age in all samples (r=0.9, p=2.5x10<sup>-133</sup>). Cumulative lifetime stress but not childhood or current stress predicted age acceleration in GTP (p=0.012) and MPI-P (p=0.021). Moreover, epigenetic age acceleration predicted depression (GTP: p=0.002; Conte: p=0.014) and panic disorder (p=0.007). In secondary analyses, we examined the effect of lifetime stress on individual CpGs of the DNA methylation age predictor. After correcting for multiple comparisons, we identified in both GTP and MPI-P a stress-regulated CpG near MCAM, a gene implicated in aging-related diseases, including cardiovascular disease and cancers.
Cumulative lifetime stress, but not childhood or current stress, and psychiatric phenotypes are associated with accelerated epigenetic aging. Our findings may explain the accelerated cellular aging and increased disease risk associated with chronic stress and psychiatric disorders.
This is a cross-sectional study aiming to understand the early characteristics and background of bone health impairment in clinically well children with Fontan circulation.
We enrolled 10 clinically well children with Fontan palliation (operated >5 years before study entrance, Tanner stage ≤3, age 12.1 ± 1.77 years, 7 males) and 11 healthy controls (age 12.0 ± 1.45 years, 9 males) at two children’s hospitals. All patients underwent peripheral quantitative CT. For the Fontan group, we obtained clinical characteristics, NYHA class, cardiac index by MRI, dual x-ray absorptiometry, and biochemical studies. Linear regression was used to compare radius and tibia peripheral quantitative CT measures between Fontan patients and controls.
All Fontan patients were clinically well (NYHA class 1 or 2, cardiac index 4.85 ± 1.51 L/min/m2) and without significant comorbidities. Adjusted trabecular bone mineral density, cortical thickness, and bone strength index at the radius were significantly decreased in Fontan patients compared to controls with mean differences −30.13 mg/cm3 (p = 0.041), −0.31 mm (p = 0.043), and −6.65 mg2/mm4 (p = 0.036), respectively. No differences were found for tibial measures. In Fontan patients, the mean height-adjusted lumbar bone mineral density and total body less head z scores were −0.46 ± 1.1 and −0.63 ± 1.1, respectively, which are below the average, but within normal range for age and sex.
In a clinically well Fontan cohort, we found significant bone deficits by peripheral quantitative CT in the radius but not the tibia, suggesting non-weight-bearing bones may be more vulnerable to the unique haemodynamics of the Fontan circulation.
The introduction of 2,4-D–resistant soybean and cotton provided growers a new POST active ingredient to include in weed management programs. The technology raises concerns regarding potential 2,4-D off-target movement to sensitive vegetation, and spray droplet size is the primary management factor focused on to reduce spray particle drift. The objective of this study was to investigate the droplet size distribution, droplet velocity, and particle drift potential of glyphosate plus 2,4-D choline pre-mixture (Enlist Duo®) applications with two commonly used venturi nozzles in a low-speed wind tunnel. Applications with the TDXL11004 nozzle had larger DV0.1 (291 µm), DV0.5 (544 µm), and DV0.9 (825 µm) values compared with the AIXR11004 nozzle (250, 464, and 709 µm, respectively), and slower average droplet velocity (8.1 m s−1) compared with the AIXR11004 nozzle (9.1 m s−1). Nozzle type had no influence on drift deposition (P = 0.65), drift coverage (P = 0.84), and soybean biomass reduction (P = 0.76). Although the TDXL11004 nozzle had larger spray droplet size, the slower spray droplet velocity could have influenced the nozzle particle drift potential. As a result, both TDXL11004 and AIXR11004 nozzles had similar spray drift potential. Further studies are necessary to understand the impact of droplet velocity on drift potential at field scale and test how different tank solutions, sprayer configurations, and environmental conditions could influence the droplet size and velocity dynamics and consequent drift potential in pesticide applications.
Neonatal aortic thrombosis is a rare occurrence but can be life-threatening. Most aortic thrombosis in neonates is related to umbilical artery catheters. A case of a neonate with a spontaneous aortic thrombosis is described here along with a comprehensive review of the literature for cases of neonatal aortic thrombosis not related to any intravascular device or procedure. The aetiologies of these spontaneous thromboses and the relevance of hypercoagulable disorders are discussed. The cases were analysed for odds of death by treatment method adjusted for era. The reference treatment method was thrombolysis and anticoagulation. No other treatment modality had significantly lower odds than the reference. Surgery alone had higher odds for death than the reference, but this may be confounded by severity of case. The management recommendations for clinicians encountering neonates with spontaneous neonatal aortic thrombosis are discussed.
A new transmission electron microscopy (TEM) specimen preparation method that utilizes a combination of focused ion beam (FIB) methods and ultramicrotomy is demonstrated. This combined method retains the benefit of site-specific sampling by FIB but eliminates ion beam-induced damage except at specimen edges and allows recovery of many consecutive sections. It is best applied to porous and/or fine-grained materials that are amenable to ultramicrotomy but are located in bulk samples that are not. The method is ideal for unique samples from which every specimen is precious, and we demonstrate its utility on fine-grained material from the one-of-a-kind Paris meteorite. Compared with a specimen prepared by conventional FIB methods, the final sections are uniformly thin and free from re-deposition and curtaining artifacts common in FIB specimens prepared from porous, heterogeneous samples.
The use of cover crops in soybean production systems has increased in recent years. There are many questions surrounding cover crops—specifically about benefits to crop production and most effective herbicides for spring termination. No studies evaluating cover crop termination have been conducted across a wide geographic area, to our knowledge. Therefore, field experiments were conducted in 2016 and 2017 in Arkansas, Indiana, Mississippi, Missouri, and Wisconsin for spring termination of regionally specific cover crops. Glyphosate-, glufosinate-, and paraquat-containing treatments were applied between April 15 and April 29 in 2016 and April 10 and April 20 in 2017. Visible control of cover crops was determined 28 days after treatment. Glyphosate-containing herbicide treatments were more effective than paraquat- and glufosinate-containing treatments, providing 71% to 97% control across all site years. Specifically, glyphosate at 1.12 kg ha−1 applied alone or with 2,4-D at 0.56 kg ha−1, saflufenacil at 0.025 kg ha−1, or clethodim at 0.56 kg ha−1 provided the most effective control on all grass cover crop species. Glyphosate-, paraquat-, or glufosinate-containing treatments were generally most effective on broadleaf cover crop species when applied with 2,4-D or dicamba. Results from this research indicate that proper herbicide selection is crucial to successfully terminate cover crops in the spring.