Understanding of gravity sensing and response is critical to long-term human habitation in space and can provide new advantages for terrestrial agriculture. To this end, the altered gene expression ...profile induced by microgravity has been repeatedly queried by microarray and RNA-seq experiments to understand gravitropism. However, the quantification of altered protein abundance in space has been minimally investigated.
Proteomic (iTRAQ-labelled LC-MS/MS) and transcriptomic (RNA-seq) analyses simultaneously quantified protein and transcript differential expression of three-day old, etiolated Arabidopsis thaliana seedlings grown aboard the International Space Station along with their ground control counterparts. Protein extracts were fractionated to isolate soluble and membrane proteins and analyzed to detect differentially phosphorylated peptides. In total, 968 RNAs, 107 soluble proteins, and 103 membrane proteins were identified as differentially expressed. In addition, the proteomic analyses identified 16 differential phosphorylation events. Proteomic data delivered novel insights and simultaneously provided new context to previously made observations of gene expression in microgravity. There is a sweeping shift in post-transcriptional mechanisms of gene regulation including RNA-decapping protein DCP5, the splicing factors GRP7 and GRP8, and AGO4,. These data also indicate AHA2 and FERONIA as well as CESA1 and SHOU4 as central to the cell wall adaptations seen in spaceflight. Patterns of tubulin-α 1, 3,4 and 6 phosphorylation further reveal an interaction of microtubule and redox homeostasis that mirrors osmotic response signaling elements. The absence of gravity also results in a seemingly wasteful dysregulation of plastid gene transcription.
The datasets gathered from Arabidopsis seedlings exposed to microgravity revealed marked impacts on post-transcriptional regulation, cell wall synthesis, redox/microtubule dynamics, and plastid gene transcription. The impact of post-transcriptional regulatory alterations represents an unstudied element of the plant microgravity response with the potential to significantly impact plant growth efficiency and beyond. What's more, addressing the effects of microgravity on AHA2, CESA1, and alpha tubulins has the potential to enhance cytoskeletal organization and cell wall composition, thereby enhancing biomass production and growth in microgravity. Finally, understanding and manipulating the dysregulation of plastid gene transcription has further potential to address the goal of enhancing plant growth in the stressful conditions of microgravity.
Electrochemical carbon dioxide (CO2) reduction is a promising strategy to synthesize valuable multi-carbon products (C2+) while sequestering CO2 and utilizing intermittent renewable electricity. For ...industrial deployment, CO2 electrolyzers must remain stable while selectively producing concentrated C2+ products at high rates with modest cell voltages. Here, we present a membrane electrode assembly (MEA) electrolyzer that converts CO2 to C2+ products. We perform side-by-side comparisons of state-of-the-art electrolyzer systems and find that the MEA provides the most stable cell voltage and product selectivity. We then demonstrate an approach to release concentrated gas and liquid products from the cathode outlet. This strategy achieves ∼50% and ∼80% Faradaic efficiency for ethylene and C2+ products, respectively, with cathode outlet concentrations of ∼30% ethylene and the direct production of ∼4 wt % ethanol. We characterize stability by operating continuously for 100 h, the longest stable ethylene production at current densities >100 mA cm−2 among reported CO2 electrolyzers.
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•Membrane electrode assembly design enables stable CO2 electroreduction•∼50% Faradaic efficiency for ethylene and ∼80% Faradaic efficiency for C2+ products•>30% gas outlet concentration of ethylene and direct production of ∼4 wt % ethanol•Continuous 100 h operation at >100 mA cm−2
The advent of low-cost renewable electricity and rising atmospheric CO2 has led to a focus on electrochemical CO2 reduction as a means toward low-carbon-intensity fuels and chemical feedstocks. The conversion of CO2 into C2+ hydrocarbons and oxygenates (i.e., products containing two or more carbon atoms) is attractive in light of large global market demand for these high-energy-density products. A limited number of prior studies have focused on performance in the reaction rate regime above 100 mA cm−2 generally viewed as necessary for industrial deployment. In these works, gas diffusion electrodes are used in liquid electrolyte electrochemical flow cells, which suffer in system stability and/or energy efficiency. We overcome this issue by developing a membrane electrode assembly-based electrolyzer. The combined catalyst and system strategy produces concentrated gas and liquid products and maintains performance during long-term (100 h) uninterrupted operation.
Electrochemical CO2 reduction is a promising strategy to synthesize valuable multi-carbon products (C2+) while sequestering CO2 and utilizing intermittent renewable electricity. Here, we present a stable membrane electrode assembly (MEA) electrolyzer that converts CO2 to C2+ products. This strategy achieves ∼50% and ∼80% selectivity for ethylene and C2+ products, respectively, with cathode outlet concentrations of ∼30% ethylene and the direct production of ∼4 wt % ethanol. We characterize stability by operating continuously for 100 h with steady ethylene production.
Tropical savannas have a ground cover dominated by C4 grasses, with fire and herbivory constraining woody cover below a rainfall-based potential. The savanna biome covers 50% of the African ...continent, encompassing diverse ecosystems that include densely wooded Miombo woodlands and Serengeti grasslands with scattered trees. African savannas provide water, grazing and browsing, food and fuel for tens of millions of people, and have a unique biodiversity that supports wildlife tourism. However, human impacts are causing widespread and accelerating degradation of savannas. The primary threats are land cover-change and transformation, landscape fragmentation that disrupts herbivore communities and fire regimes, climate change and rising atmospheric CO2. The interactions among these threats are poorly understood, with unknown consequences for ecosystem health and human livelihoods. We argue that the unique combinations of plant functional traits characterizing the major floristic assemblages of African savannas make them differentially susceptible and resilient to anthropogenic drivers of ecosystem change. Research must address how this functional diversity among African savannas differentially influences their vulnerability to global change and elucidate the mechanisms responsible. This knowledge will permit appropriate management strategies to be developed to maintain ecosystem integrity, biodiversity and livelihoods.
The development and morphology of crop plants have been profoundly altered by evolution under cultivation, initially through unconscious selection, without deliberate foresight, and later by directed ...breeding. Wild wheats remain an important potential source of variation for modern breeders; however, the sequence and timing of morphological changes during domestication are not fully resolved.
We grew and measured 142 wheat accessions representing different stages in wheat evolution, including three independent domestication events, and compared their morphological traits to define the morphospace of each group.
The results show that wild and domesticated wheats have overlapping morphospaces, but each also occupies a distinct area of morphospace from one another. Polyploid formation in wheat increased leaf biomass and seed weight but had its largest effects on tiller loss. Domestication continued to increase the sizes of wheat leaves and seeds and made wheat grow taller, with more erect architecture. Associated changes to the biomass of domesticated wheats generated more grains and achieved higher yields. Landrace improvement subsequently decreased the numbers of tillers and spikes, to focus resource allocation to the main stem, accompanied by a thicker main stem and larger flag leaves. During the Green Revolution, wheat height was reduced to increase the harvest index and therefore yield. Modern wheats also have more erect leaves and larger flower biomass proportions than landraces.
Quantitative trait history in wheat differs by trait. Some trait values show progressive changes in the same direction (e.g. leaf size, grain weight), whereas others change in a punctuated way at particular stages (e.g. canopy architecture), and other trait values switch directions during wheat evolution (e.g. plant height, flower biomass proportion). Agronomically valued domestication traits arose during different stages of wheat history, such that modern wheats are the product of >10 000 years of morphological evolution.
Niger is highly vulnerable to rainfall variability, often with adverse socioeconomic consequences. This study examined observed subseasonal rainfall variability during Niger's monsoon season (May to ...September). Using k-means clustering of dekadal (ten-day) rainfall, a typology was developed for the annual evolution of the monsoon season. Year-to-year rainfall variability for each of the first few dekads of the season is modest, but the middle, or peak of the rainy season demonstrates large interannual variability. Clustering analysis of annual timeseries for each dekad of the season revealed two types of monsoon progression. The distinction between the two types is strongly dependent on differences during the latter half of the season. For the first and third ten-day periods in August, and the first ten days in September, the two groups of years are more distinct. These results imply that while reliable prediction of the timing of anomalous onsets will be challenging, due to the relatively narrow range of uncertainty historically, there are opportunities for further exploration of dynamic and or statistical predictors or precursors using this typology that could potentially provide better information for decision-makers, especially with respect to agriculture.
The Annotated Constitution of Japan: A Handbook for the first time makes the entirety of Japan's constitution accessible in English. The book consists of a historical and contextual overview of how ...the constitution came into being, followed by descriptions of each of its 103 articles; the meaning of the text, interpretive disputes, academic theories and leading cases arising under them. The book also points out the many subtle distinctions between the English version and the Japanese, some of which arose from the charter's unique provenance. With contributors representing a broad range of expertise in various areas of Japanese law, the book is written to appeal to academics, students and general readers alike. It is intended to be the first port of call for anyone needing to understand the fundamentals of Japanese constitutional law, whether from the perspective of Japanese studies, comparative law, or political science, but unable to access the text and related literature available in Japanese. Key reference documents in English and Japanese are included as appendices for ease of reference.
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