protaTETHER - A Method for the Incorporation of Variable Linkers in Protein Fusions Reveals Impacts of Linker Flexibility in a PKAc-GFP Fusion Protein

Protein fusions are of fundamental importance in the study of cellular biology and the elucidation of cell signaling pathways, and the importance of linkers for the proper function of protein fusions is well documented in the literature. However, there are few convenient methods available to experimentalists for the systematic implementation of linkers in protein fusions. In this work, we describe a universal approach to the creation and insertion of focused linker libraries into protein fusions. This process, deemed protaTETHER, utilizes reiterative oligomer design, PCR-mediated linker library generation, and restriction enzyme-free cloning methods in a straightforward, three-step cloning process. We utilize a fusion between the catalytic subunit of cAMP-dependent protein kinase A (PKAc) and green fluorescent protein (GFP) for the development of the protaTETHER method, implementing small linker libraries that vary by length, sequence, and predicted secondary structural elements. We analyze the impact of linker length and sequence on the expression, activity, and subcellular localization of the PKAc-GFP fusions, and use these results to select a PKAc-GFP fusion construct with robust expression and enzymatic activity. Based upon the results of both biochemical experiments and molecular modeling, we determine that linker flexibility is more important than linker length for optimal kinase activity and expression

Factor Structure of the Barriers to Physical Activity Scale for Youth with Visual Impairments

Youth with visual impairments (VI) often experience unique barriers to physical activity (PA) compared to their sighted peers (Armstrong et al., 2018). A psychometrically sound scale for assessing barriers to PA for youth with VI is needed to facilitate research. The purpose of this paper was to confirm the ability of the previously identified three-factor structure of the Physical Activity Barriers Questionnaire for youth with Visual Impairments (PABQ-VI) to produce scores considered to be valid and reliable (Armstrong et al., 2020; Armstrong et al., 2018) that perform equally well across age, VI severity, and gender. Our results supported the three-factor structure and that the PABQ-VI produces scores considered valid and reliable. Mean, variance, and correlation differences were found in personal, social, and environmental barriers for age and VI severity, but not gender. Researchers can use the PABQ-VI to test and evaluate ways to reduce barriers for this population

Corn Silage Yield and Quality, and Soil Health Metrics After Fall Cover Crop Grazing

Integrated crop-livestock systems can potentially produce more product per unit of land with minimal impacts on soil health and cash crop quality. In the Upper Midwest there is an opportunity to graze fall cover crops (CC) after winter wheat in a corn-wheat rotation. In East Lansing, Michigan, two CC treatments: 1) a pure brassica mixture (PURE), and 2) a complex mixture containing legumes, warm and cool season grasses, and brassicas (MIX) were planted after wheat, and grazed by lambs in the fall seasons of 2019 to 2021. The following year, soil health, corn yield and quality were measured from plots corresponding to a non-grazed control and plots grazed in October, November, and December. There was no significant effect on spring soil bulk density and penetration resistance (PR) regardless of CC mixture or the timing of grazing, although PR was numerically higher in the grazed plots. Corn crude protein, acid detergent fiber, and neutral detergent fiber were not different across graze date or CC treatments (P \u3e 0.05), although corn contained more starch when grown after MIX grazed in November (P=0.02). The difference in starch was possibly an artifact of spatial variability across the site. Corn dry matter yield was lower in the non-grazed control (15.35 Mg ha-1) when compared to the grazing treatments in October (17.37 Mg ha-1) and December (17.19 Mg ha-1) (P=0.03). Grazing cover crops in the fall may improve corn yield the following year without causing soil compaction or changing corn quality

The structural and functional coupling of two molecular machines, the ribosome and the translocon

Ribosomes synthesizing secretory and membrane proteins are bound to translocons at the membrane of the endoplasmic reticulum (ER). Both the ribosome and translocon are complex macromolecular machines whose structural and functional interactions are poorly understood. A new study by Pool (Pool, M.R. 2009. J. Cell Biol. 185:889–902) has now shown that the structure of the translocon is dictated by the identity of the protein being synthesized by the ribosome, thereby demonstrating that the two macromolecular machines are structurally coupled for functional purposes. The study also identifies an unexpected component in the apparent molecular linkage that connects the two machines, a discovery that shows the current view of translocon structure is oversimplified

The Political Ecology of Cereal Seed Development in Africa: A History of Selection

Agricultural history and the history of seeds in sub?Saharan Africa are an aggregate effect of individual day?to?day decisions by farmers. The role of seeds within an agricultural system can be a valuable indicator of both social and natural time since farmers' seed selections indicate both natural conditions – moisture, pests, soils – and short?term, season by season farm decisions about labour, potential yield vs risk and market potential. In the immediate future, international donors and African governments are planning that African farmers will receive their seeds from a global political structure that anticipates, perhaps wishfully, economic and political stability. Those expectations of development specialists are ones that failed at the end of the twentieth century. Will seed selection by African farmers in the twenty?first century take place in an ideal free market of infinite choice or in real?world conditions fraught with uncertainty of supply, climate fluctuations and unintended consequences within complex local ecologies

A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity

This work contributes to the UK-China Virtual Joint Centre N-Circle (grant number BB/N013484/1), SuperG (funded under EU Horizon 2020 programme) and ADVENT (grant number NE/M019691/1). DRC was supported by the UK-China Virtual joint Centre for Agricultural Nitrogen (CINAg, BB/N013468/1) and the UK-Brazil Virtual Joint Centre to deliver enhanced N-use efficiency via an integrated soil-plant systems approach (NUCLEUS), which are jointly supported by Newton fund via UK BBSRC and NERC. Jaak Truu received financing from Estonian Research Council (grant PRG548).Peer reviewedPublisher PD

Participatory, agroecological and gender-sensitive approaches to improved nutrition : a case study in Malawi

This paper examines a long-term participatory agriculture and nutrition program in northern Malawi that successfully improved child growth, crop diversity and food security through innovative educational strategies and sustainable agriculture. The farmer-led approaches used mobilized communities to apply agroecological methods and improved child feeding practices, as well as addressing unequal gender relations. Efforts to link agriculture to child health outcomes took time: 3 years before the goal was realized, with application of interdisciplinary approaches

Training compliance control yields improvements in drawing as a function of beery scores

Many children have difficulty producing movements well enough to improve in sensori-motor learning. Previously, we developed a training method that supports active movement generation to allow improvement at a 3D tracing task requiring good compliance control. Here, we tested 7–8 year old children from several 2nd grade classrooms to determine whether 3D tracing performance could be predicted using the Beery VMI. We also examined whether 3D tracing training lead to improvements in drawing. Baseline testing included Beery, a drawing task on a tablet computer, and 3D tracing. We found that baseline performance in 3D tracing and drawing co-varied with the visual perception (VP) component of the Beery. Differences in 3D tracing between children scoring low versus high on the Beery VP replicated differences previously found between children with and without motor impairments, as did post-training performance that eliminated these differences. Drawing improved as a result of training in the 3D tracing task. The training method improved drawing and reduced differences predicted by Beery scores

Maize yield and profitability tradeoffs with social, human and environmental performance: is sustainable intensification feasible?

Sustainable intensification (SI) has been regarded as the basis for environmentally sound and equitable agricultural development. Field based assessment of technologies needs to move beyond production and economic performance to include environment, social and human condition. In this study we systematically consider all five domains of SI based on participatory action research (PAR) initiated in 2012 at three Central Malawi sites that varied in agroecology from low to high potential. Fifteen SI indicators were assessed for four technologies: sole maize (Zea mays L.) with 0 and recommended fertilization (69 kg N ha−1 and 9 kg P ha−1), pigeonpea (Cajanus Cajun (L.) Millsp.)-maize intercrop (half rate fertilizer), and doubled up legume rotation (DLR, a pigeonpea- groundnut intercrop) sequenced with maize at half rate fertilizer in that phase. Through radar charts SI performance and tradeoffs were visualized, and causal loop analysis allowed identification of research gaps. SI indicator assessments included crop performance from on-farm trials, profitability, modeled probability of food sufficiency, risk of crop failure and ratings of technologies by women farmers who were engaged in evaluation of technologies through participatory research. The PAR included six mother trials, 236 baby trial farmers and a survey that was carried out with 324 farmers (baby trial farmers plus control farmers) to document socioeconomic factors and management practices on focal fields. Replicated mother trials further provided the basis for simulation modeling (APSIM) of weather-associated crop failure risk and slow processes such as soil carbon (C) accrual. Radar charts were used to visualize SI performance of the technologies. Environmental performance of the two pigeonpea-diversified technologies was variable, but generally high compared with sole maize systems, due to gains in vegetative biomass, duration of cover and biological nitrogen (N) fixation. Maize production and economic assessment varied by site, and with steeper tradeoffs for legume diversification in the mesic site, less so in the marginal site. The domains of social and human capacity building were superior for legume integration, notably in terms of diverse diet, food security and farmer preferences (notably, female farmers generally favored legume crops). Performance varied by site with legume systems most beneficial at the most marginal site, including less risk of crop failure than unfertilized maize. Causal loop analyses identified regulators of SI that require further attention, notably: crop-livestock conflicts and opportunities, male-female control of legume crop production, and residue management. Overall, the SI indicators framework provided a systematic means to consider tradeoffs and opportunities associated with novel crop combinations and management practices

Perennial grain crops in the West Soudanian Savanna of Mali: perspectives from agroecology and gendered spaces

Perennial grain crops may play an important role in environmentally sound and socially just food systems for Africa. We study the future possibility of integrating perennial grains into Malian farming systems from the perspective of agroecology, and more specifically using a gendered space approach. We interviewed 72 farmers across the sorghum-growing region of Mali. We found that perennial grains offer a vision for transforming human relations with nature that mirrors the resource sharing of customary land tenure, including patterns of extensive and intensive land use in time and space. Women interviewees identified a broad set of potential advantages and challenges to perennial grain production. Advantages include reduced labour, saving seed, and improving food security. Women farmers were concerned about livestock, water access, and resource limitations. We argue that perennial grains may increase access to land and natural resources for women farmers. Perennial grains may improve soil quality, reduce labour early in the rainy season, and provision more resources from fallow lands. Pastoralists stand to benefit from improved pastures in the dry season. We conclude that investments are needed to develop viable crop types in consideration of the complexity of West African farming systems and the local needs of women farmers and pastoralists