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Peanut (Arachis hypogaea L.) and maize (Zea mays L.) are essential crops for Ghana’s economy and food security, but weed infestation poses a significant threat to their cultivation. Crop rotations influence weed communities, but little is known about these processes in peanut-cropping systems in West Africa. This study investigated the impact of different crop rotations and input levels on weed communities in Ghana over 3 yr. Results showed that low inputs (absence of herbicide and fertilization) favored species richness, while higher input levels (weed control with herbicides and fertilizer use) reduced it. Diversity and evenness were also affected by inputs, with varying patterns across locations and seasons. Weed population growth rates (λ) varied significantly by location and treatment; all management programs resulted in increasing weed populations. Principal component analysis revealed distinct associations between weed species and crop management. The majority of weed species exhibited a generalist behavior and did not associate with a particular management. However, billygoat weed (Ageratum conyzoides L.) and Benghal dayflower (Commelina benghalensis L.) were positively associated with high-input systems, while purple nutsedge (Cyperus rotundus L.) exhibited strong associations with low and medium inputs. The weed–crop rotation dynamics described here demonstrate how management drives the selection of weed species that are more pervasive and interfere with important food crops in Ghanaian agriculture.
To investigate the latent factor structure and construct validity of the Verbal Series Attention Test (VSAT) across clinical patient populations.
Participants and Methods:
Participants included a consecutive series of clinical patients presenting with a primary memory complaint. Each patient underwent a comprehensive neuropsychological assessment and provided informed consent to allow their clinical data to be used for research. Groups formed included 1) No Neurocognitive Disorder [NoND, N=262, mean age=68.8, mean education=16.2, mean MMSE=28.3], 2) Mild Neurocognitive Disorder [MildND, N=337, mean age=72.3, mean education=15.4, mean MMSE=28.7], and 3)
Major Neurocognitive Disorder [MajorND, N=524, mean age=76.5, mean education=14.5, mean MMSE=19.0] with etiologies including suspected Alzheimer’s disease and/or vascular pathology. Latent factors were investigated using exploratory factor analysis (EFA).
Results:
EFA was conducted using SAS 9.4 software and the promax (oblique) rotation to reveal the latent factors of the eight timed items of the VSAT in each of the three clinical groups. The structure was essentially identical in all three groups with two primary factors consistently emerging identified as 1-Complex Attention and 2-Simple Attention. Each factor had four items loading with a correlation range of > 0.37 x < 0.92. The internal consistency (Cronbach’s alpha) for the VSAT total score in each group was excellent (NoND a=0.83, MildND a=0.81, and MajorND a=0.84). To investigate construct validity, the VSAT items were entered into factor analysis with measures of attention and executive function (i.e., Digit Span [forward, backward, sequence], Trail Making Test A & B, semantic fluency (animals), Controlled Oral Word Association Test [COWAT, FAS]). All three patient groups were combined (N=950) given the VSAT’s consistent factor structure. Using the same EFA procedure as before, two main factors emerged with the VSAT Complex Attention variables loading on a general complex attention/working memory factor including Trails B, semantic fluency, and Digit Span subtests. The VSAT Simple Attention items loaded on a general attention factor with the VSAT Simple Attention variables and Trails A. COWAT did not load significantly on either factor.
Conclusions:
The latent factor structure of the VSAT was consistent across patient populations with excellent internal consistency in each clinical group. The Complex and Simple Attention factors of the VSAT loaded on factors with similar variables identifying the anticipated latent factor structure demonstrating the construct validity of the VSAT across a wide spectrum of cognitive impairment in patients with primary memory complaints ranging from NoND to MajorND. This supports the use of the VSAT in patients across neurocognitive severity. Future studies will further explore additional psychometric properties of this instrument.
Poor mood and quality of life is common among patients with medically intractable seizures. Many of these patients are not candidates for seizure focus resection and continue to receive standard medical care. Responsive neurostimulation (RNS) has been an effective approach to reduce seizure frequency for nonsurgical candidates. Previous research using RNS clinical trial participants has demonstrated improved mood and quality of life when patients received RNS-implantation earlier in their medically resistant epilepsy work-up (Loring et al., 2021). We aimed to describe the level of depression and quality of life in adults with medical resistant epilepsy, treated with RNS, presenting to an outpatient clinic.
Participants and Methods:
This pilot study was conducted among 11 adult epilepsy patients treated with RNS at the epilepsy specialty clinic at Baylor College of Medicine. Ages of participants ranged from 18-56 (M=32.01, SD=12.37) with a mean education of 12.43 (SD=0.85). The majority of the participants identified as White (White=72.2%; Hispanic/Latino/a=14.3%, Other=7.1%). We also present pre- and post-RNS preliminary results of a subset of 4 patients for whom pre and post implantation data was available. Depression symptoms were assessed through the Beck Depression Inventory, 2nd Edition (BDI-II) and quality of life was determined using the Quality of Life in Epilepsy (QoLiE-31).
Results:
Patients reported minimal symptoms of depression (M=5.45, SD=4.03) and good overall quality of life (M=71.18, SD=14.83) after RNS. Participants’ scores on their overall quality of life ranged from 50 to 95 (100=better quality of life). The QoLiE-31 showed high scores on emotional wellbeing (M=69.45, SD=14.56) and cognitive functioning (M=65.36, SD=16.66) domains. Post-hoc analysis revealed a significant difference in the cognitive functioning domain of QoLiE-31 before (M=44.75, SD=12.58) and after (M=51.0, SD=11.58) RNS implantation(t(3)=-3.78, p=0.016. Additionally, overall QoLiE score approached statistical significance when comparing pre-RNS (M=44.75 SD=9.29) to post-RNS (M=49.75 SD=11.62; t(3)=-2.01, p = 0.069). No significant differences were evident on seizure worry, energy/fatigue, medication effects, and social functioning domains of QoLiE-31 before and after RNS treatment.
Conclusions:
These pilot study results suggest low levels of depression with this population post-RNS implantation. Additionally, there is preliminary evidence to suggest improved patient-rated cognitive functioning and overall quality of life. While this is a small study population, the results have important implications for patients with intractable epilepsy, even with those form who surgical resection may not be possible. Future studies with large enough samples to examine moderating and mediating factors to mood and quality of life changes post-RNS will be important.
The impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health is still being unravelled. It is important to identify which individuals are at greatest risk of worsening symptoms. This study aimed to examine changes in depression, anxiety and post-traumatic stress disorder (PTSD) symptoms using prospective and retrospective symptom change assessments, and to find and examine the effect of key risk factors.
Method
Online questionnaires were administered to 34 465 individuals (aged 16 years or above) in April/May 2020 in the UK, recruited from existing cohorts or via social media. Around one-third (n = 12 718) of included participants had prior diagnoses of depression or anxiety and had completed pre-pandemic mental health assessments (between September 2018 and February 2020), allowing prospective investigation of symptom change.
Results
Prospective symptom analyses showed small decreases in depression (PHQ-9: −0.43 points) and anxiety [generalised anxiety disorder scale – 7 items (GAD)-7: −0.33 points] and increases in PTSD (PCL-6: 0.22 points). Conversely, retrospective symptom analyses demonstrated significant large increases (PHQ-9: 2.40; GAD-7 = 1.97), with 55% reported worsening mental health since the beginning of the pandemic on a global change rating. Across both prospective and retrospective measures of symptom change, worsening depression, anxiety and PTSD symptoms were associated with prior mental health diagnoses, female gender, young age and unemployed/student status.
Conclusions
We highlight the effect of prior mental health diagnoses on worsening mental health during the pandemic and confirm previously reported sociodemographic risk factors. Discrepancies between prospective and retrospective measures of changes in mental health may be related to recall bias-related underestimation of prior symptom severity.
Paramedics are a vital component of the Emergency Medical Services (EMS) workforce and the United States health care system. The continued provision of high-quality care demands constantly improving education at accredited institutions. To date, only limited characteristics of paramedic education in the United States have been documented and studied in the literature. The objective of this study was to describe the educational infrastructure of accredited paramedic programs in the United States in 2018.
Methods:
This is a retrospective, cross-sectional evaluation of the 2018 paramedic program annual report from The Committee on Accreditation of Educational Programs for the EMS Professions (CoAEMSP; Rowlett, Texas USA). The dataset includes detailed program metrics. Additionally, questions concerning program characteristics, demographics, and resources were asked as part of the evaluation. Resource availability was assessed via the Resource Assessment Matrix (RAM) with a benchmark of 80%. Included in the analysis are all paramedic programs with students enrolled. Descriptive statistics were calculated (median, [interquartile range/IQR]).
Results:
A total of 677 programs submitted data (100% response rate). Of these, 626 met inclusion criteria, totaling 17,422 students. Program annual enrollment varied greatly from one to 362 with most programs having small sizes (18 students [IQR 12-30]). Program duration was 12 months [IQR 12-16] with total hours of instruction being approximately 1,174 [IQR 1069-1304], 19% of which were dedicated to clinical experience. Full-time faculty sizes were small (two faculty members [IQR 1-3]) with most programs (80%) having annual operating budgets below USD$500,000. For programs with an annual budget below USD$100,000 (34% of programs), annual enrollment was approximately 14 students [IQR 9-21]. Degrees conferred by programs included certificates (90%), associate degrees (55%), and bachelor’s degree (2%). Simulation access was assessed with nearly all (100%) programs reporting simple task trainers and 84% of programs investing in advanced simulation manikins. Seventy-eight percent of programs met the RAM benchmark.
Conclusion:
Most paramedic educational programs in the United States have small annual enrollments with low numbers of dedicated faculty and confer certificates and associate degrees. Nearly one-quarter of paramedic educational programs are not adequately resourced. This study is limited by self-reported data to the national accreditation agency. Future work is needed to identify program characteristics that are associated with high performance.
The climate crisis requires nations to achieve human well-being with low national levels of carbon emissions. Countries vary from one another dramatically in how effectively they convert resources into well-being, and some nations with low levels of emissions have relatively high objective and subjective well-being. We identify urgent research and policy agendas for four groups of countries with either low or high emissions and well-being indicators. Least studied are those with low well-being and high emissions. Understanding social and political barriers to switching from high-carbon to lower-carbon modes of production and consumption, and ways to overcome them, will be fundamental.
A glyphosate-resistant Palmer amaranth biotype was confirmed in central Georgia. In the field, glyphosate applied to 5- to 13-cm-tall Palmer amaranth at three times the normal use rate of 0.84 kg ae ha−1 controlled this biotype only 17%. The biotype was controlled 82% by glyphosate at 12 times the normal use rate. In the greenhouse, I50 values (rate necessary for 50% inhibition) for visual control and shoot fresh weight, expressed as percentage of the nontreated, were 8 and 6.2 times greater, respectively, with the resistant biotype compared with a known glyphosate-susceptible biotype. Glyphosate absorption and translocation and the number of chromosomes did not differ between biotypes. Shikimate was detected in leaf tissue of the susceptible biotype treated with glyphosate but not in the resistant biotype.
Research was conducted from 2011 to 2014 to determine weed population
dynamics and frequency of glyphosate-resistant (GR) Palmer amaranth with
herbicide programs consisting of glyphosate, dicamba, and residual
herbicides in dicamba-tolerant cotton. Five treatments were maintained in
the same plots over the duration of the experiment: three sequential POST
applications of glyphosate with or without pendimethalin plus diuron PRE;
three sequential POST applications of glyphosate plus dicamba with and
without the PRE herbicides; and a POST application of glyphosate plus
dicamba plus acetochlor followed by one or two POST applications of
glyphosate plus dicamba without PRE herbicides. Additional treatments
included alternating years with three sequential POST applications of
glyphosate only and glyphosate plus dicamba POST with and without PRE
herbicides. The greatest population of Palmer amaranth was observed when
glyphosate was the only POST herbicide throughout the experiment. Although
diuron plus pendimethalin PRE in a program with only glyphosate POST
improved control during the first 2 yr, these herbicides were ineffective by
the final 2 yr on the basis of weed counts from soil cores. The lowest
population of Palmer amaranth was observed when glyphosate plus dicamba were
applied regardless of PRE herbicides or inclusion of acetochlor POST.
Frequency of GR Palmer amaranth was 8% or less when the experiment was
initiated. Frequency of GR Palmer amaranth varied by herbicide program
during 2012 but was similar among all herbicide programs in 2013 and 2014.
Similar frequency of GR Palmer amaranth across all treatments at the end of
the experiment most likely resulted from pollen movement from Palmer
amaranth treated with glyphosate only to any surviving female plants
regardless of PRE or POST treatment. These data suggest that GR Palmer
amaranth can be controlled by dicamba and that dicamba is an effective
alternative mode of action to glyphosate in fields where GR Palmer amaranth
exists.
Silicon carbide power devices are purported to be capable of operating at very high temperatures. Current commercially available SiC MOSFETs from a number of manufacturers have been evaluated to understand and quantify the aging processes and temperature dependencies that occur when operated up to 350°C. High temperature constant positive bias stress tests demonstrated a two times increase in threshold voltage from the original value for some device types, which was maintained indefinitely but could be corrected with a long negative gate bias. The threshold voltages were found to decrease close to zero and the on-state resistances increased quite linearly to approximately five or six times their room temperature values. Long term thermal aging of the dies appears to demonstrate possible degradation of the ohmic contacts. This appears as a rectifying response in the I-V curves at low drain-source bias. The high temperature capability of the latest generations of these devices has been proven independently; provided that threshold voltage management is implemented, the devices are capable of being operated and are free from the effects of thermal aging for at least 70 hours cumulative at 300°C.
Gattini and CSTAR have been installed at Dome A, Antarctica, which provide time-series photometric data for a large number of pulsating variable stars. We present the study for several variable stars with the data collected with the two facilities in 2009 to demonstrate the scientific potential of observations from Dome A for asteroseismology.
Supernova 2012A was discovered on 7.39UT, January, 2012 in the nearby galaxy NGC 3239 at an unfiltered magnitude of 14.6 and classified spectroscopically as a Type IIP event. Here, we present the optical photometric and spectroscopic follow-up of the event during 14d to 130d post explosion.
In 2008 January the 24th Chinese expedition team successfully deployed the Chinese Small Telescope ARray (CSTAR) to Dome A, the highest point on the Antarctic plateau. CSTAR consists of four 14.5cm optical telescopes, each with a different filter (g, r, i and open) and has a 4.5°×4.5° field of view (FOV). Based on the CSTAR data, initial statistics of astronomical observational site quality and light curves of variable objects were obtained. To reach higher photometric quality, we are continuing to work to overcome the effects of uneven cirrus cloud cirrus, optical “ghosts” and intra-pixel sensitivity. The snow surface stability is also tested for further astronomical observational instrument and for glaciology studies.
Within the Herschel key project “The Warm And Dense ISM” (WADI) we systematically observea number of prominent photon-dominated regions (PDRs) to measure the impact of varying UVfields on the energy balance, the chemical and dynamical structure of heated molecularclouds.
PLATO is a 6 tonne completely self-contained robotic observatory that provides its own heat, electricity, and satellite communications. It was deployed to Dome A in Antarctica in January 2008 by the Chinese expedition team, and is now in its second year of operation. PLATO is operating four 14.5cm optical telescopes with 1k × 1k CCDs, a wide-field sky camera with a 2k × 2k CCD and Sloan g, r, i filters, a fibre-fed spectrograph to measure the UV to near-IR sky spectrum, a 0.2m terahertz telescope, two sonic radars giving 1m resolution data on the boundary layer to a height of 180m, a 15m tower, meteorological sensors, and 8 web cameras. Beginning in 2010/11 PLATO will be upgraded to support a Multi Aperture Scintillation Sensor and three AST3 0.5m schmidt telescopes, with 10k × 10 CCDs and 100TB/annum data requirements.
Observations using the HIFI and PACS instruments aboard the Herschelsatellite provide a unique way to study the chemical inventory,the dynamics, and the energy balance in dense interstellar clouds heated byUV radiation. We propose a comprehensive observing program to revealthe details of the interaction of massive young stars with theirparental molecular clouds.
We present a unique approach combining biological manipulation with advanced imaging tools to examine silica cell wall synthesis in the diatom Thalassiosira pseudonana. The innate capabilities of diatoms to form complex 3D silica structures on the nano- to micro-scale exceed current synthetic approaches because they use a fundamentally different formation process. Understanding the molecular details of the process requires identifying structural intermediates and correlating their formation with genes and proteins involved. This will aid in development of approaches to controllably alter structure, facilitating the use of diatoms as a direct source of nanostructured materials. In T. pseudonana, distinct silica morphologies were observed during formation of different cell wall substructures, and three different scales of structural organization were identified. At all levels, structure formation correlated with optimal design properties for the final product. These results provide a benchmark of measurements and new insights into biosilicification processes, potentially also benefiting biomimetic approaches.
We conducted a nested case-control study to determine potential risk factors for developing encephalitis from West Nile virus (WNV) infection. Retrospective medical chart reviews were completed for 172 confirmed WNV cases hospitalized in Houston between 2002 and 2004. Of these cases, 113 had encephalitis, including 17 deaths, 47 had meningitis, and 12 were fever cases; 67% were male. Homeless patients were more likely to be hospitalized from WNV compared to the general population. A multiple logistic regression model identified age [odds ratio (OR) 1·1, P<0·001], history of hypertension, including those cases taking hypertension-inducing drugs (OR 2·9, P=0·012), and history of cardiovascular disease (OR 3·5, P=0·061) as independent risk factors for developing encephalitis from WNV infection. After adjusting for age, race/ethnicity (being black) (OR 12·0, P<0·001), chronic renal disease (OR 10·6, P<0·001), hepatitis C virus (OR 23·1, P=0·0013), and immunosuppression (OR 3·9, P=0·033) were identified as risk factors for death from WNV infection.
Significant progress has been made in the last decade toward an understanding of the intergalactic He II absorption. At redshifts $z<2.8$, individual absorbers are found to be ionised mainly by a hard quasar continuum, but their ionisation states vary considerably and the ionising radiation field may have contributions from a soft stellar continuum. The He II opacity increases significantly at $z\sim 2.8$, suggesting a possible end of the general reionisation of intergalactic He II. Using the massive SDSS database and UV selection with HST and GALEX, we have found new quasars at $z>3.5$, with detected He II absorption. Future observations will pinpoint the epoch of reionisation of the intergalactic He II.
In universal relaxation, a material's complex dielectric susceptibility follows a fractional power law f1-n where 0 < n < 1 over multiple decades of frequency. In a variety of materials, including Ba0.5Sr0.5Ti03, dielectric relaxation has been observed to follow this universal relaxation model with values of n close to 1. In this work we have shown that the universal relaxation model can be used to calculate dielectric loss even when n is very close to 1. Our calculated Q-factors agree with measured values at 1 MHz; this agreement suggests that this technique may be used for higher frequencies where network analyzer measurements and electrode parasitics complicate Q-factor determination.