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The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.
To examine whether mothers’ perceived neighbourhood food access is associated with their own and their young children’s consumption of animal-flesh food, fruits and vegetables in peri-urban areas of Cambodia.
A cross-sectional survey measured food consumption frequency and perceived neighbourhood food access, the latter including six dimensions of food availability, affordability, convenience, quality, safety and desirability. Multivariate logistic regression was used to assess the association between perceived food access and food consumption.
Peri-urban districts of Phnom Penh and Siem Reap, Cambodia
198 mothers of children between 6 and 24 months old.
Over 25 % of the mothers and 40 % of the children had low consumption (< once a day) of either animal-flesh food or fruits and vegetables. Compared with perceived high food access, perceived low food access was associated with an adjusted 5·6-fold and 4·3-fold greater odds of low animal-flesh food consumption among mothers (95 % CI 2·54, 12·46) and children (95 % CI 2·20, 8·60), respectively. Similarly, relative to perceived high food access, perceived low food access was associated with 7·6-times and 5·1-times higher adjusted odds of low fruits and vegetables consumption among mothers (95 % CI 3·22, 18·02) and children (95 % CI 2·69, 9·83), respectively.
Mothers’ perceived neighbourhood food access was an important predictor of their own and their young children’s nutrient-rich food consumption in peri-urban Cambodia. Future work is needed to confirm our findings in other urban settings and examine the role of neighbourhood food environment in the consumption of both nutrient-rich and nutrient-poor food.
There is a need for accurate, inexpensive and field-friendly methods to assess body composition in children. Bioelectrical impedance analysis (BIA) is a promising approach; however, there have been limited validation and use among young children in resource-poor settings. We aim to develop and validate population-specific prediction equations for estimating total fat mass (FM), fat free-mass (FFM) and percentage body fat (PBF) in Vietnamese children (4–7 years) using reactance and resistance from BIA, anthropometric variables and demographic information. We conducted a cross-sectional survey of 120 children. Body composition was measured using dual-energy X-ray absorptiometry (DXA), BIA and anthropometry. To develop prediction equations, we split all data into development (70 %) and validation datasets (30 %). The model performance was evaluated using predicted residual error sum of squares, root mean squared error (RMSE), mean absolute error (MAE) and R2. We identified a top performing model with the least number of parameters (age, sex, weight and resistance index or resistance and height), low RMSE (FM 0·70, FFM 0·74, PBF 3·10), low MAE (FM 0·55, FFM 0·62, PBF 2·49), high R2 (FM 0·95, FFM 0·92, PBF 0·82) and the least difference between predicted values and actual values from DXA (FM 0·03 kg or 0·01 sd, FFM 0·06 kg or 0·02 sd, PBF 0·27 % or 0·04 sd). In conclusion, we developed the first valid and highly predictive equations to estimate FM, FFM and PBF in Vietnamese children using BIA. These findings have important implications for future research on the double burden of disease and risks associated with overweight and obesity in young children.
Research demonstrates the importance of nutrition for early brain development. Few studies have examined the effectiveness of multiple micronutrient powders (MNP) on child development. This study examined the impacts of home fortification with MNP on motor and mental development, executive function and memory of children living in Bihar. This two-arm cluster-randomised effectiveness trial selected seventy health sub-centres to receive either MNP and nutrition counselling (intervention) or nutrition counselling alone (control) for 12 months. Front-line health workers delivered the intervention to all households in study communities with a child aged 6–18 months. Data were collected using cross-sectional surveys at baseline and endline by selecting households from intervention (baseline, n 2184; endline, n 2170) and control (baseline, n 2176; endline, n 2122) communities using a two-stage cluster-randomised sampling strategy. Children in the intervention group had a significantly larger improvement from baseline to endline compared with those in the control group on scores for motor and mental development (Cohen’s d, motor=0·12; 95 % CI 0·03, 0·22; mental=0·15; 95 % CI 0·06, 0·25). Greater impacts of MNP on motor and mental development were observed in children from households with higher stimulation scores at baseline compared with those with lower stimulation (Cohen’s d, motor=0·20 v. 0·09; mental=0·22 v. 0·14; Pinteraction<0·05). No significant treatment differences were seen for executive function or memory. Home fortification with MNP through the existing health infrastructure in Bihar was effective in improving motor and mental development and should be considered in combination with other child development interventions such as stimulation.
The extracellular portions of the chains that comprise
the human type I interferon receptor, IFNAR1 and IFNAR2,
have been expressed and purified as recombinant soluble
His-tagged proteins, and their interactions with each other
and with human interferon-β-1a (IFN-β-1a) were
studied by gel filtration and by cross-linking. By gel
filtration, no stable binary complexes between IFN-β-1a
and IFNAR1, or between IFNAR1 and IFNAR2 were detected.
However, a stable binary complex formed between IFN-β-1a
and IFNAR2. Analysis of binary complex formation using
various molar excesses of IFN-β-1a and IFNAR2 indicated
that the complex had a 1:1 stoichiometry, and reducing
SDS-PAGE of the binary complex treated with the cross-linking
reagent dissucinimidyl glutarate (DSG) indicated that the
major cross-linked species had an apparent M>r
consistent with the sum of its two individual components.
Gel filtration of a mixture of IFNAR1 and the IFN-β-1a/IFNAR2
complex indicated that the three proteins formed a stable
ternary complex. Analysis of ternary complex formation
using various molar excesses of IFNAR1 and the IFN-β-1a/IFNAR2
complex indicated that the ternary complex had a 1:1:1
stoichiometry, and reducing SDS-PAGE of the ternary complex
treated with DSG indicated that the major cross-linked
species had an apparent Mr consistent
with the sum of its three individual components. We conclude
that the ternary complex forms by the sequential association
of IFN-β-1a with IFNAR2, followed by the association
of IFNAR1 with the preformed binary complex. The ability
to produce the IFN-β-1a/IFNAR2 and IFN-β-1a/IFNAR1/IFNAR2
complexes make them attractive candidates for X-ray crystallography
studies aimed at determining the molecular interactions
between IFN-β-1a and its receptor.
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