Nigerians in poverty consume little wheat and wheat self-sufficiency programmes will not protect them from price shocks related to the Russia-Ukraine conflict.

The Russia-Ukraine conflict has prompted calls for resource diversification and wheat self-sufficiency programmes in import-dependent regions. Here we show that this approach would have minimal impact on poor Nigerians as wheat constitutes only 4% of their total food consumption and 8% of their starchy staple consumption. In contrast, millets, rice, cassava and tubers are ten times more important-highlighting the need for careful consideration of country-context consumption patterns in response to external food system shocks.

Dissipative self-assembly of a proline catalyst for temporal regulation of the aldol reaction.

The spatiotemporal regulation of chemical reactivity in biological systems permits a network of metabolic reactions to take place within the same cellular environment. The exquisite control of reactivity is often mediated by out-of-equilibrium structures that remain functional only as long as fuel is present to maintain the higher energy, active state. An important goal in supramolecular chemistry aims to develop functional, energy dissipating systems that approach the sophistication of biological machinery. The challenge is to create strategies that couple the energy consumption needed to promote a molecule to a higher energy, assembled state to a functional property such as catalytic activity. In this work, we demonstrated that the assembly of a spiropyran (SP) dipeptide (1) transiently promoted the proline-catalyzed aldol reaction in water when visible light was present as fuel. The transient catalytic activity emerged from 1 under light illumination due to the photoisomerization of the monomeric, O-protonated (1-MCH+) merocyanine form to the spiropyran (1-SP) state, which rapidly assembled into nanosheets capable of catalyzing the aldol reaction in water. When the light source was removed, thermal isomerization to the more stable MCH+ form caused the nanosheets to dissociate into a catalytically inactive, monomeric state. Under these conditions, the aldol reaction could be repeatedly activated and deactivated by switching the light source on and off.

Research and policy for the food-delivery revolution.

Implications for nutrition, environment, and work may be considerable.

Self-assembly of a 5-fluorouracil and camptothecin dual drug dipeptide conjugate.

Nano-formulated, combinatory therapeutics that control the spatiotemporal aspects of drug release have potential to overcome many of the challenges faced in cancer therapy. Herein, we describe a peptide nanotube functionalized with two anticancer drugs, 5-fluoruracil (5-FU) and camptothecin (CPT). The nanotube was formed via peptide self-assembly, which positioned 5-FU on the surface at the aqueous interface; whereas, CPT was sequestered within the hydrophobic walls. Thus, two different release profiles were observed: rapid release of 5-FU, followed by slower, sustained production of CPT. This profile emerged from the rapid hydrolytic cleavage of 5-FU at the aqueous/nanotube interface, which produced a smaller nanotube comprised of the peptide fragment.

From the laboratory to the consumer: Innovation, supply chain, and adoption with applications to natural resources.

We analyze the transition from innovative ideas to final marketed products. This transition occurs through two synergetic supply chains for innovation and products. Basic concepts are developed, tested, upscaled, and introduced to commercial use in the innovation supply chain. Then, the products are produced and delivered to the consumer through the product supply chain. We argue that product markets trace their birth to product innovations. These markets tend to start as noncompetitive, which rewards innovators. Credit access and risk determine the reliance on contracting and product diffusion over space and time. The innovation and product supply chains are encouraged and facilitated by public policies, such as support for research and education, intellectual property rights protection, low barriers to trade, science-based regulation, and well-functioning capital markets. We argue for multidisciplinary research incorporating knowledge from economics, business, and engineering to better understand the evolution of innovative companies and supply chains. This understanding will help the development of policies to address challenges of climate change and food security among others.

Prelimbic cortex drives discrimination of non-aversion via amygdala somatostatin interneurons.

The amygdala and prelimbic cortex (PL) communicate during fear discrimination retrieval, but how they coordinate discrimination of a non-threatening stimulus is unknown. Here, we show that somatostatin (SOM) interneurons in the basolateral amygdala (BLA) become active specifically during learned non-threatening cues and desynchronize cell firing by blocking phase reset of theta oscillations during the safe cue. Furthermore, we show that SOM activation and desynchronization of the BLA is PL-dependent and promotes discrimination of non-threat. Thus, fear discrimination engages PL-dependent coordination of BLA SOM responses to non-threatening stimuli.

COVID-19's impacts on incomes and food consumption in urban and rural areas are surprisingly similar: Evidence from five African countries.

African governments imposed mobility restrictions to suppress the spread of COVID-19. Many observers feared these measures would dramatically decrease incomes and increase food insecurity and anticipated that urban households would be much more impacted than rural ones. We use rural and urban survey data from 4000 households across five African countries to assess the pandemic's effect on incomes and food consumption. We find that a large share of the population saw incomes drop between March and July 2020. But these decreases were 43-63% smaller than predictions and early estimates, and highly correlated with the severity of restrictions. The income and food consumption impacts of the COVID-19 shock were widespread over both rural and urban areas. Policy making during a pandemic should recognize that restrictive measures will affect rural and urban, farming and non-farming, and richer and poorer households.

Light-driven dissipative self-assembly of a peptide hydrogel.

Light energy provides an attractive fuel source for energy dissipating systems because of the lack of waste production, wavelength tunability and the potential for spatial and temporal resolution. In this work, we describe a peptide-spiropyran conjugate that assembled into a transient nanofiber hydrogel in the presence of visible light, and dissociated when the light source was removed.

Quiet Revolution by SMEs in the midstream of value chains in developing regions: wholesale markets, wholesalers, logistics, and processing.

Small and medium enterprises (SMEs) in the midstream (processors, wholesalers and wholesale markets, and logistics) segments of transforming value chains have proliferated rapidly over the past several decades in Africa, Asia, and Latin America. Their spread has been most rapid in the long transitional stage between the traditional and modern stages, when value chains grow long and developed with urbanization but are still fragmented, before consolidation. Most of Sub-Saharan Africa and South Asia, and parts of the other regions, are in that stage. The midstream SMEs in output and input value chains are important to overall food security (moving about 65% of food consumed in Africa and South Asia), and to employment, farmers, poor consumers, and the environment. The midstream of value chains is neglected in the national and international debates as the "missing middle." We found that it is indeed not missing but rather hidden from the debate, hence "the hidden middle." The midstream SMEs grow quickly and succeed where enabling conditions are present. Our main policy recommendations are to support the SMEs further growth through a focus on infrastructure investment, in particular on wholesale markets and roads, a reduction of policy-related constraints such as excessive red tape, and regulation for food safety and good commercial practices.

"Pivoting" by food industry firms to cope with COVID-19 in developing regions: E-commerce and "copivoting" delivery intermediaries.

Coronavirus disease 2019 and related lockdown policies in 2020 shocked food industry firms' supply chains in developing regions. Firms "pivoted" to e-commerce to reach consumers and e-procurement to reach processors and farmers. "Delivery intermediaries" copivoted with food firms to help them deliver and procure. This was crucial to the ability of the food firms to pivot. The pandemic was a "crucible" that induced this set of fast-tracking innovations, accelerating the diffusion of e-commerce and delivery intermediaries, and enabling food industry firms to redesign, at least temporarily, and perhaps for the long term, their supply chains to be more resilient, and to weather the pandemic, supply consumers, and contribute to food security. We present a theoretical model to explain these firm strategies, and then apply the framework to classify firms' practical strategies. We focus on cases in Asia and Latin America. Enabling policy and infrastructural conditions allowed firms to pivot and copivot fluidly.

The Processed food revolution in African food systems and the Double Burden of Malnutrition.

African consumers have purchased increasing amounts of processed food over the past 50 years. The opportunity cost of time of women and men has increased as more of them work outside the home, driving them to buy processed food and food prepared away from home to save arduous home-processing and preparation labor. In the past several decades, this trend has accelerated with a surge on the supply side of the processing sector and small and medium enterprises (SMEs) and large private companies making massive aggregate investments. Packaged, industrialized, ultra-processed foods and sugar-sweetened beverages (SSBs) are a growing proportion of the processed food consumed. Also, in the past several decades, overweight and obesity have joined the long-standing high levels of stunting and wasting among children and extreme thinness among women of childbearing age. Together these phenomena have formed a double burden of malnutrition (DBM). The DBM has emerged as an important health problem in sub-Saharan Africa. The rise of the DBM and the increase in ultra-processed food consumption are linked. Policy makers face a dilemma. On the one hand, purchases of processed food are driven by long-term factors, such as urbanization, increased income, and employment changes, and thus policy cannot change the pursuit of convenience and labor-saving food. Moreover, much processed food, like packaged milk, is a boon to nutrition, and the processed food system is a major source of jobs for women. On the other hand, the portion (some 10-30%) of processed food that is ultra-processed is a public health challenge, and policy must address its detrimental effects on disease burden. The global experience suggests that double duty actions are most important as are selected policies focused on healthy weaning foods for addressing stunting and taxes on SSBs, nutrition labeling, and other measures can steer consumers away from unhealthy ultra-processed foods to addressing obesity and possibly child nutrition and stunting. We recommend that African governments consider these policy options, but note that the current extreme fragmentation of the processing sector, consisting of vast numbers of informal SMEs in sub-Saharan Africa, and the limited administrative/implementation capacity of many African governments require pursuing this path only gradually.

Sustainability standards in global agrifood supply chains.

Agrifood supply chains contribute to many environmental and social problems. Sustainability standards-rules that supply chain actors may follow to demonstrate their commitment to social equity and/or environmental protection-aim to mitigate such problems. We provide a narrative review of the effects of many distinct sustainability standards on different supply chain actors spanning multiple crops. Furthermore, we discuss five emerging questions-causality, exclusion, compliance and monitoring, excess supply and emerging country markets-and identify directions for future research. We find that, while sustainability standards can help improve the sustainability of production processes in certain situations, they are insufficient to ensure food system sustainability at scale, nor do they advance equity objectives in agrifood supply chains.

Agricultural input credit in Sub-Saharan Africa: Telling myth from facts.

Recent evidence shows that many Sub-Saharan African farmers use modern inputs, but there is limited information on how these inputs are financed. We use recent nationally representative data from four countries to explore input financing and the role of credit therein. A number of our results contradict "conventional wisdom" found in the literature. Our results consistently show that traditional credit use, formal or informal, is extremely low (across credit type, country, crop and farm size categories). Instead, farmers primarily finance modern input purchases with cash from nonfarm activities and crop sales. Tied output-labor arrangements (which have received little empirical treatment in the literature) appear to be the only form of credit relatively widely used for farming.

Development of a novel series of non-natural triaryl agonists and antagonists of the Pseudomonas aeruginosa LasR quorum sensing receptor.

Bacterial chemical communication, through a process called quorum sensing (QS), plays a central role in infection in numerous bacterial pathogens. Quorum sensing in Pseudomonas aeruginosa employs a series of small molecule receptors including the master QS regulator, LasR. In this study we investigate a non-natural triaryl series of LasR ligands using a combination of structure activity relationship studies and computational modeling. These studies have enabled the identification of key structural requirements for ligand binding and have revealed a new strategy for inducing the therapeutically relevant antagonism of LasR.

Simultaneous Denoising, Deconvolution, and Demixing of Calcium Imaging Data.

We present a modular approach for analyzing calcium imaging recordings of large neuronal ensembles. Our goal is to simultaneously identify the locations of the neurons, demix spatially overlapping components, and denoise and deconvolve the spiking activity from the slow dynamics of the calcium indicator. Our approach relies on a constrained nonnegative matrix factorization that expresses the spatiotemporal fluorescence activity as the product of a spatial matrix that encodes the spatial footprint of each neuron in the optical field and a temporal matrix that characterizes the calcium concentration of each neuron over time. This framework is combined with a novel constrained deconvolution approach that extracts estimates of neural activity from fluorescence traces, to create a spatiotemporal processing algorithm that requires minimal parameter tuning. We demonstrate the general applicability of our method by applying it to in vitro and in vivo multi-neuronal imaging data, whole-brain light-sheet imaging data, and dendritic imaging data.

Rabies Virus CVS-N2c(ΔG) Strain Enhances Retrograde Synaptic Transfer and Neuronal Viability.

Virally based transsynaptic tracing technologies are powerful experimental tools for neuronal circuit mapping. The glycoprotein-deletion variant of the SAD-B19 vaccine strain rabies virus (RABV) has been the reagent of choice in monosynaptic tracing, since it permits the mapping of synaptic inputs to genetically marked neurons. Since its introduction, new helper viruses and reagents that facilitate complementation have enhanced the efficiency of SAD-B19(ΔG) transsynaptic transfer, but there has been little focus on improvements to the core RABV strain. Here we generate a new deletion mutant strain, CVS-N2c(ΔG), and examine its neuronal toxicity and efficiency in directing retrograde transsynaptic transfer. We find that by comparison with SAD-B19(ΔG), the CVS-N2c(ΔG) strain exhibits a reduction in neuronal toxicity and a marked enhancement in transsynaptic neuronal transfer. We conclude that the CVS-N2c(ΔG) strain provides a more effective means of mapping neuronal circuitry and of monitoring and manipulating neuronal activity in vivo in the mammalian CNS.

The quiet revolution in Asia's rice value chains.

There is a rapid transformation afoot in the rice value chain in Asia. The upstream is changing quickly-farmers are undertaking capital-led intensification and participating in burgeoning markets for land rental, fertilizer and pesticides, irrigation water, and seed, and shifting from subsistence to small commercialized farms; in some areas landholdings are concentrating. Midstream, in wholesale and milling, there is a quiet revolution underway, with thousands of entrepreneurs investing in equipment, increasing scale, diversifying into higher quality, and the segments are undergoing consolidation and vertical coordination and integration. Mills, especially in China, are packaging and branding, and building agent networks in wholesale markets, and large mills are building direct relationships with supermarkets. The downstream retail segment is undergoing a "supermarket revolution," again with the lead in change in China. In most cases the government is not playing a direct role in the market, but enabling this transformation through infrastructural investment. The transformation appears to be improving food security for cities by reducing margins, offering lower consumer rice prices, and increasing quality and diversity of rice. This paper discusses findings derived from unique stacked surveys of all value chain segments in seven zones, more and less developed, around Bangladesh, China, India, and Vietnam.

Dendritic inhibition in the hippocampus supports fear learning.

Fear memories guide adaptive behavior in contexts associated with aversive events. The hippocampus forms a neural representation of the context that predicts aversive events. Representations of context incorporate multisensory features of the environment, but must somehow exclude sensory features of the aversive event itself. We investigated this selectivity using cell type-specific imaging and inactivation in hippocampal area CA1 of behaving mice. Aversive stimuli activated CA1 dendrite-targeting interneurons via cholinergic input, leading to inhibition of pyramidal cell distal dendrites receiving aversive sensory excitation from the entorhinal cortex. Inactivating dendrite-targeting interneurons during aversive stimuli increased CA1 pyramidal cell population responses and prevented fear learning. We propose subcortical activation of dendritic inhibition as a mechanism for exclusion of aversive stimuli from hippocampal contextual representations during fear learning.

Septo-hippocampal GABAergic signaling across multiple modalities in awake mice.

Hippocampal interneurons receive GABAergic input from the medial septum. Using two-photon Ca(2+) imaging of axonal boutons in hippocampal CA1 of behaving mice, we found that populations of septo-hippocampal GABAergic boutons were activated during locomotion and salient sensory events; sensory responses scaled with stimulus intensity and were abolished by anesthesia. We found similar activity patterns among boutons with common putative postsynaptic targets, with low-dimensional bouton population dynamics being driven primarily by presynaptic spiking.