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ABSTRACT IntroductionCurcumin is a naturally occurring compound with anti‐inflammatory, cholesterol‐lowering, antidiabetic, and antioxidant properties. Curcumin can be biosynthesized in microbial hosts despite being found natively inCurcuma longaroots. ObjectivesIt is unclear whether curcumin is transported out of microbial cells, binds to the inner or outer cell membrane, or accumulates inside. This study aims to gain a better understanding of curcumin's behavior after its formation in the host, which could lead to the development of new approaches to improve curcumin production. Material and MethodsAdvanced imaging techniques, including SEM, TEM, SHS, and TPF, were utilized to understand the behavior of curcumin within and outside of engineeredEscherichia colicells. ResultsCurcumin was biosynthesized from ferulic acid in engineeredE. coliBL21(DE3) by coexpressing 4‐coumarate: CoA ligase and curcuminoid synthase. Second harmonic scattering (SHS) spectroscopy experiments utilized curcumin as a probe to investigate the surface binding of curcumin onto livingE. colicells with experimentally determined adsorption free energy,ΔG, values of −14.0 kcal/mol. By employing second harmonic and two‐photon fluorescence imaging methods, the spatial distribution of curcumin aggregates was determined. Electron microscopy images revealed the presence of curcumin aggregates within the cells, at the surface, and in the media. ConclusionThese experiments demonstrate that curcumin biosynthesis from ferulic acid leads to significant product aggregation within the cells, which could ultimately halt production by inducing cell death. Understanding the localization, transport, and removal of curcumin is crucial in developing more efficient biosynthetic pathways to enhance its production in microbial systems. 

Abstract An overview is presented of our current understanding and open questions related to magnetic reconnection in solar flares and the near-sun (within around 20$$R_{s}$$ $R_s$) solar wind. The solar-flare-related topics include the mechanisms that facilitate fast energy release and that control flare onset, electron energization, ion energization and abundance enhancement, electron and ion transport, and flare-driven heating. Recent observations and models suggesting that interchange reconnection of multipolar magnetic fields within coronal holes could provide the energy required to drive the fast solar wind are also discussed. Recentin situobservations that reconnection in the heliospheric current sheet close to the sun drives energetic ions are also presented. The implications ofin situobservations of reconnection in the Earth space environment for understanding flares are highlighted. Finally, the impact of emerging computational and observational tools for understanding flare dynamics are discussed. 

Abstract We report observations of direct evidence of energetic protons being accelerated above ∼400 keV within the reconnection exhaust of a heliospheric current sheet (HCS) crossing by NASA’s Parker Solar Probe (PSP) at a distance of ∼16.25 solar radii (R_s) from the Sun. Inside the exhaust, both the reconnection-generated plasma jet and the accelerated protons up to ∼400 keV propagated toward the Sun, unambiguously establishing their origin from HCS reconnection sites located antisunward of PSP. Within the core of the exhaust, PSP detected stably trapped energetic protons up to ∼400 keV, which is ≈1000 times greater than the available magnetic energy per particle. The differential energy spectrum of the accelerated protons behaved as a pure power law with spectral index of ∼−5. Supporting simulations using thekglobalmodel suggest that the trapping and acceleration of protons up to ∼400 keV in the reconnection exhaust are likely facilitated by merging magnetic islands with a guide field between ∼0.2 and 0.3 of the reconnecting magnetic field, consistent with the observations. These new results, enabled by PSP’s proximity to the Sun, demonstrate that magnetic reconnection in the HCS is a significant new source of energetic particles in the near-Sun solar wind. Our findings of in situ particle acceleration via magnetic reconnection at the HCS provide valuable insights into this fundamental process, which frequently converts the large magnetic field energy density in the near-Sun plasma environment and may be responsible for heating the Sun’s atmosphere, accelerating the solar wind, and energizing charged particles to extremely high energies in solar flares. 

Today's robotic laboratories for drones are housed in a large room. At times, they are the size of a warehouse. These spaces are typically equipped with permanent devices to localize the drones, e.g., Vicon Infrared cameras. Significant time is invested to fine-tune the localization apparatus to compute and control the position of the drones. One may use these laboratories to develop a 3D multimedia system with miniature sized drones configured with light sources. As an alternative, this brave new idea paper envisions shrinking these room-sized laboratories to the size of a cube or cuboid that sits on a desk and costs less than 10K dollars. The resulting Dronevision (DV) will be the size of a 1990s Television. In addition to light sources, its Flying Light Specks (FLSs) will be network-enabled drones with storage and processing capability to implement decentralized algorithms. The DV will include a localization technique to expedite development of 3D displays. It will act as a haptic interface for a user to interact with and manipulate the 3D virtual illuminations. It will empower an experimenter to design, implement, test, debug, and maintain software and hardware that realize novel algorithms in the comfort of their office without having to reserve a laboratory. In addition to enhancing productivity, it will improve safety of the experimenter by minimizing the likelihood of accidents. This paper introduces the concept of a DV, the research agenda one may pursue using this device, and our plans to realize one. 

Abstract We survey 20 reconnection outflow events observed by Magnetospheric MultiScale in the low-βand high-Alfvén-speed regime of the Earth’s magnetotail to investigate the scaling of ion bulk heating produced by reconnection. The range of inflow Alfvén speeds (800–4000 km s⁻¹) and inflow ionβ(0.002–1) covered by this study is in a plasma regime that could be applicable to the solar corona and flare environments. We find that the observed ion heating increases with increasing inflow (upstream) Alfvén speed,V_A, based on the reconnecting magnetic field and the upstream plasma density. However, ion heating does not increase linearly as a function of available magnetic energy per particle, ${{\mathit{m}}_{\mathrm{i}}{\mathit{V}}_{\mathrm{A}}}^2$. Instead, the heating increases progressively less as ${{\mathit{m}}_{\mathrm{i}}{\mathit{V}}_{\mathrm{A}}}^2$rises. This is in contrast to a previous study using the same data set, which found that electron heating in this high-Alfvén-speed and low-βregime scales linearly with ${{\mathit{m}}_{\mathrm{i}}{\mathit{V}}_{\mathrm{A}}}^2$, with a scaling factor nearly identical to that found for the low-V_Aand high-βmagnetopause. Consequently, the ion-to-electron heating ratio in reconnection exhausts decreases with increasing upstreamV_A, suggesting that the energy partition between ions and electrons in reconnection exhausts could be a function of the available magnetic energy per particle. Finally, we find that the observed difference in ion and electron heating scaling may be consistent with the predicted effects of a trapping potential in the exhaust, which enhances electron heating, but reduces ion heating. 

Abstract We report observations of multiple subscale reconnecting current sheets embedded inside a large-scale heliospheric current sheet (HCS) reconnection exhaust. The discovery was made possible by the unusual skimming trajectory of Parker Solar Probe through a sunward-directed HCS exhaust, sampling structures convecting with the exhaust outflows for more than 3 hr during Encounter 14, at a radial distance of ∼17 solar radii. A large number of subscale current sheets (SCSs) were detected inside the HCS exhaust. Remarkably, five SCSs showed direct evidence for reconnection, displaying near-Alfvénic outflow jets and bifurcated current sheets. The reconnecting SCSs all had small magnetic shears (27°–81°), i.e., strong guide fields. The thickness of the subscale reconnecting current sheets ranged from ∼60 km to ∼5000 km (∼20–2000 ion inertial lengths). The SCS exhausts were directed predominantly in the normal or out-of-plane direction of the HCS, i.e., nearly orthogonal to the HCS exhaust direction. The presence of multiple low-magnetic-shear reconnecting current sheets inside a large-scale exhaust could be associated with coalescence of multiple large flux ropes inside the HCS exhaust. The orientation of some SCS exhausts was partly in the ecliptic plane of the HCS, which may indicate that the coalescence process is highly three-dimensional. Since the coalescence process is likely short-lived, the detection of five such events inside a single HCS crossing could imply the common occurrence of flux rope coalescence in large-scale HCS reconnection exhausts. 

Abstract We have surveyed 21 reconnection exhaust events observed by Magnetospheric MultiScale in the low-plasma-βand high-Alfvén-speed regime of the Earth’s magnetotail to investigate the scaling of electron bulk heating produced by reconnection. The ranges of inflow Alfvén speed and inflow electronβ_ecovered by this study are 800–4000 km s⁻¹and 0.001–0.1, respectively, and the observed heating ranges from a few hundred electronvolts to several kiloelectronvolts. We find that the temperature change in the reconnection exhaust relative to the inflow, ΔT_e, is correlated with the inflow Alfvén speed,V_Ax,in, based on the reconnecting magnetic field and the inflow plasma density. Furthermore, ΔT_eis linearly proportional to the inflowing magnetic energy per particle, ${m_{\mathrm{i}}{V}_{\mathrm{Ax},\mathrm{in}}}^2$, and the best fit to the data produces the empirical relation ΔT_e= 0.020 ${m_{\mathrm{i}}{V}_{\mathrm{Ax},\mathrm{in}}}^2$, i.e., the electron temperature increase is on average ∼2% of the inflowing magnetic energy per particle. This magnetotail study extends a previous magnetopause reconnection study by two orders of magnitude in both magnetic energy and electronβ, to a regime that is comparable to the solar corona. The validity of the empirical relation over such a large combined magnetopause–magnetotail plasma parameter range ofV_A∼ 10–4000 km s⁻¹andβ_e∼ 0.001–10 suggests that one can predict the magnitude of the bulk electron heating by reconnection in a variety of contexts from the simple knowledge of a single parameter: the Alfvén speed of the ambient plasma.