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Morphological and anatomical measurements of Solanum lycopersicum L. seedlings grown with diluted seawater in the greenhouse were analyzed to understand the effects of non-conventional water on the growth and development of the species. The salinity of the non-conventional water ranged from 8.15mS/cm to 9.85mS/cm which corresponds to 0.5% to 2.0% seawater (v/v) in freshwater dilution. The results indicate that no significant difference exists in anatomical and morphological growth and development of the species compared to those grown with freshwater. The study concludes that adoption of this type of non-conventional water resource in greenhouse crop production will save between 415,000 to 1,660,000 liters of freshwater for the United States fresh harvest-producing greenhouses per day. It further concludes that the results represent an effective freshwater conservation strategy for the United States and the world at large. 

Inorganic fertilizers are often used in the United States in golf courses putting green maintenance. We used milled plant biomass on putting greens to test the hypothesis that organic biostimulants used in putting green maintenance can achieve similar results as inorganic fertilizers. Dilapidated putting greens, #4 and #14, with conspicuous patches at the L.E. Ramey Golf Course in Kingsville, TX, were selected for the study. Each green was split in half with one half selected for treatment and the other half maintained as the control and treated with NPK. Milled Medicago sativa L. mixed with milled high auxin-containing plant species in a ratio of 10:1 was used to test the hypothesis. The mixture was applied in the bio-treated section of the two greens while the golf course management continued to apply inorganic fertilizers on the control section of the study greens. Patch count on the greens was conducted once a week utilizing a randomly placed 1 by 1 m quadrant. Also, soil moisture measurement was taken twice a week on the greens to understand soil moisture retention due to the treatments. Patch count indicates that the bio-treated sections grew and filled significantly faster than the sections treated with inorganic fertilizers. Regression analysis of data collected between July 13th and July 27th indicates a strong linear biostimulant/patch growth relationship (R2 = 0.75 and 0.92) on Greens #4 and #14 respectively. Also, soil moisture data indicates significantly higher moisture retention on the putting green sections treated with the biostimulant. 

Tuning the properties of magnetic topological materials is of interest to realize exotic physical phenomena, new quantum phases and quasiparticles, and topological spintronic devices. However, current topological materials exhibit Curie temperature (TC) values far below those needed for practical applications. In recent years, significant progress has been made to control and optimize TC, particularly through defect-engineering of these structures. Most recently, we reported TC values up to 80 K for (MnSb2Te4)x(Sb2Te3)1−x when 0.7 ≤ x ≤ 0.85 by controlling the composition x and the Mn content in these structures during molecular beam epitaxy growth. In this study, we show further enhancement of the TC, as high as 100 K, by maintaining high Mn content and reducing the growth rate from 0.9 nm/min to 0.5 nm/min. Derivative curves of the Hall resistance and the magnetization reveal the presence of two TC components contributing to the overall value and suggest TC1 and TC2 have distinct origins: excess Mn in MnSb2Te4 septuple layers (SLs) and high Mn content in Sb2−yMnyTe3 quintuple layer (QL) alloys, respectively. To elucidate the mechanisms promoting higher TC values in this system, we show evidence of enhanced structural disorder due to the excess Mn that occupies not only Sb sites but also Te sites, leading to the formation of a new crystal structure for these materials. Learning to control defects that enhance desired magnetic properties and understanding the mechanisms that promote high TC in magnetic topological materials such as (Mn1+ySb2−yTe4)x(Sb2−yMnyTe3)1−x is of great importance to achieve practical quantum devices. 

An efficient photovoltaic power converter is a critical element in laser power beaming systems for maximizing the end-to-end power transfer efficiency while minimizing beam reflections from the receiver for safety considerations. We designed a multilayer absorber that can efficiently trap monochromatic light from broad incident angles. The proposed design is built on the concept of a one-way coherent absorber with inverse-designed aperiodic multilayer front- and back-reflectors that enable maximal optical absorption in a thin-film photovoltaic material for broad angles. We argue that the broad bandwidth is achieved through an optimization search process that automatically engineers the modal content of the cavity to create multiple overlapping resonant modes at the desired angle or frequency range. A realistic design is provided based on GaAs thin films with inverse-designed multilayer binary AlAs/AlGaAs mirrors. The proposed device can pave the way for efficient optical power beaming systems. 

Abstract Elemental sulfur (S₈⁰)‐oxidising Sulfolobales (Archaea) dominate high‐temperature acidic hot springs (>80°C, pH <4). However, genomic analyses of S₈⁰‐oxidising members of the Sulfolobales reveal a patchy distribution of genes encoding sulfur oxygenase reductase (SOR), an S₈⁰disproportionating enzyme attributed to S₈⁰oxidation. Here, we report the S₈⁰‐dependent growth of two Sulfolobales strains previously isolated from acidic hot springs in Yellowstone National Park, one of which associated with bulk S₈⁰during growth and one that did not. The genomes of each strain encoded different sulfur metabolism enzymes, with only one encoding SOR. Dialysis membrane experiments showed that direct contact is not required for S₈⁰oxidation in the SOR‐encoding strain. This is attributed to the generation of hydrogen sulfide (H₂S) from S₈⁰disproportionation that can diffuse out of the cell to solubilise bulk S₈⁰to form soluble polysulfides (S_x²⁻) and/or S₈⁰nanoparticles that readily diffuse across dialysis membranes. The Sulfolobales strain lacking SOR required direct contact to oxidise S₈⁰, which could be overcome by the addition of H₂S. High concentrations of S₈⁰inhibited the growth of both strains. These results implicate alternative strategies to acquire and metabolise sulfur in Sulfolobales and have implications for their distribution and ecology in their hot spring habitats. 

Abstract Despite over a century of study, it is unknown if continental hydrothermal fields support high-temperature subsurface biospheres. Cinder Pool is among the deepest hot springs in Yellowstone and is widely studied due to unique sulfur geochemistry that is attributed to hydrolysis of molten elemental sulfur at ∼18 m depth that promotes several chemical reactions that maintain low sulfide, low oxygen, and a moderate pH of ∼4.0. Following ∼100 years of stability, Cinder Pool underwent extreme visual and chemical change (acidification) in 2018. Here, we show that depth-resolved geochemical and metagenomic-based microbial community analyses pre- (2016) and post-acidification (2020) indicate the changes are likely attributable to feedbacks between geological/geochemical processes, sulfur oxidation by subsurface Sulfolobales Archaea, and the disappearance of molten sulfur at depth. These findings underscore the dynamic and rapid feedback between the geosphere and biosphere in continental hydrothermal fields and suggest subsurface biospheres to be more prevalent in these systems than previously recognized. 

Abstract BackgroundComputational approaches in STEM foster creative extrapolations of ideas that extend the bounds of human perception, processing, and sense-making. Inviting teachers to explore computational approaches in STEM presents opportunities to examine shifting relationships to inquiry that support transdisciplinary learning in their classrooms. Similarly, play has long been acknowledged as activity that supports learners in taking risks, exploring the boundaries and configurations of existing structures, and imagining new possibilities. Yet, play is often overlooked as a crucial element of STEM learning, particularly for adolescents and adults. In this paper, we explorecomputational playas an activity that supports teachers’ transdisciplinary STEM learning. We build from an expansive notion of computational activity that involves jointly co-constructing and co-exploring rule-based systems in conversation with materials, collaborators, and communities to work towards jointly defined goals. We situate computation within STEM-rich making as a playful context for engaging in authentic, creative inquiry. Our research asksWhat are the characteristics of play and computation within computational play? And, in what ways does computational play contribute to teachers’ transdisciplinary learning? ResultsTeachers from grades 3–12 participated in a professional learning program that centered playful explorations of materials and tools using computational approaches: making objects based on rules that produce emergent behaviors and iterating on those rules to observe the effects on how the materials behaved. Using a case study and descriptions of the characteristics of computational play, our results show how familiarity of materials and the context of play encouraged teachers to engage in transdisciplinary inquiry, to ask questions about how materials behave, and to renegotiate their own relationships to disciplinary learning as they reflected on their work. ConclusionsWe argue computational play is a space of wonderment where iterative conversations with materials create opportunities for learners to author forms of transdisciplinary learning. Our results show how teachers and students can learn together in computational play, and we conclude this work can contribute to ongoing efforts in the design of professional and transdisciplinary learning environments focused on the intersections of materiality, play, and computation. 

Abstract Forbs (“wildflowers”) are important contributors to grassland biodiversity but are vulnerable to environmental changes. In a factorial experiment at 94 sites on 6 continents, we test the global generality of several broad predictions: (1) Forb cover and richness decline under nutrient enrichment, particularly nitrogen enrichment. (2) Forb cover and richness increase under herbivory by large mammals. (3) Forb richness and cover are less affected by nutrient enrichment and herbivory in more arid climates, because water limitation reduces the impacts of competition with grasses. (4) Forb families will respond differently to nutrient enrichment and mammalian herbivory due to differences in nutrient requirements. We find strong evidence for the first, partial support for the second, no support for the third, and support for the fourth prediction. Our results underscore that anthropogenic nitrogen addition is a major threat to grassland forbs, but grazing under high herbivore intensity can offset these nutrient effects.