139 research outputs found
Collateral Pathways from the Ventromedial Hypothalamus Mediate Defensive Behaviors
SummaryThe ventromedial hypothalamus (VMH) was thought to be essential for coping with threat, although its circuit mechanism remains unclear. To investigate this, we optogenetically activated steroidogenic factor 1 (SF1)-expressing neurons in the dorsomedial and central parts of the VMH (VMHdm/c), and observed a range of context-dependent somatomotor and autonomic responses resembling animals’ natural defensive behaviors. By activating independent pathways emanating from the VMHdm/c, we demonstrated that VMHdm/c projection to the dorsolateral periaqueductal gray (dlPAG) induces inflexible immobility, while the VMHdm/c to anterior hypothalamic nucleus (AHN) pathway promotes avoidance. Consistent with the behavior changes induced by VMH to AHN pathway activation, direct activation of the AHN elicited avoidance and escape jumping, but not immobility. Retrograde tracing studies revealed that nearly 50% of PAG-projecting VMHdm/c neurons send collateral projection to the AHN and vice versa. Thus, VMHdm/c neurons employ a one-to-many wiring configuration to orchestrate multiple aspects of defensive behaviors
Micro Deep Drawing of C1100 Conical-cylindrical Cups
AbstractMicro deep drawing was prompted by the rapid development of micro electro mechanical systems, electron industries, new energy, and biomedical in recent years because of its mass production, high efficiency, high precision, low cost and no pollution. However, most researches concentrated on micro cylindrical cups, few studies were reported on other shaped parts. Micro deep drawing of micro conical-cylindrical cups was investigated in this study by using a micro blanking-deep drawing multiple operation mould. The specimen material was pure copper C1100 with a thickness of 50μm which was thermally treated in vacuum condition at 723K for 1h. Micro deep drawing experiments were carried out at room temperature on a universal testing machine at a drawing velocity of 0.05mm/s with the lubrication of polyethylene (PE) film. The results showed that micro conical-cylindrical cups with internal conical bottom diameter of only 0.4mm were well formed. The drawing force and limiting drawing ratio (LDR) micro conical-cylindrical cups were also discussed at the end of this paper
Design of multifunctional color routers with Kerker switching using generative adversarial networks
To achieve optoelectronic devices with high resolution and efficiency, there
is a pressing need for optical structural units that possess an ultrasmall
footprint yet exhibit strong controllability in both the frequency and spatial
domains. For dielectric nanoparticles, the overlap of electric and magnetic
dipole moments can scatter light completely forward or backward, which is
called Kerker theory. This effect can expand to any multipoles and any
directions, re-named as generalized Kerker effect, and realize controllable
light manipulation at full space and full spectrum using well-designed
dielectric structures. However, the complex situations of multipole couplings
make it difficult to achieve structural design. Here, generative artificial
intelligence (AI) is utilized to facilitate multi-objective-oriented structural
design, wherein we leverage the concept of "combined spectra" that consider
both spectra and direction ratios as labels. The proposed generative
adversarial network (GAN) is named as DDGAN (double-discriminator GAN) which
discriminates both images and spectral labels. Using trained networks, we
achieve the simultaneous design for scattering color and directivities, RGB
color routers, as well as narrowband light routers. Notably, all generated
structures possess a footprint less than 600x600 nm indicating their potential
applications in optoelectronic devices with ultrahigh resolution
Poly[[chloridodimethanol(μ3-pyridine-2,3-dicarboxylato)europium(III)] methanol monosolvate]
The asymmetric unit of the title compound, {[Eu(C7H3NO4)Cl(CH3OH)2]·CH3OH}n, contains one EuIII ion, one pyridine 2,3-dicarboxylate dianion (PDC), two CH3OH molecules coordinating to the metal atom, one coordinating chloride and one lattice occluded CH3OH molecule. In the crystal, each PDC anion coordinates to three adjacent EuIII ions by the pyridine N and O atoms of the carboxylate groups. The EuIII cation is eightfold coordinated by four carboxylate O atoms, one pyridine N atom, two MeOH and one chloride anion in the form of a distorted polyhedron. Extended coordination of the PDC ligand lead to the formation of a two-dimensional coordination polymer parallel to (10-1)
Optimal Design of Plant Canopy Based on Light Interception: A Case Study With Loquat
Canopy architecture determines the light distribution and light interception in the canopy. Reasonable shaping and pruning can optimize tree structure; maximize the utilization of land, space and light energy; and lay the foundation for achieving early fruiting, high yield, health and longevity. Due to the complexity of loquat canopy architecture and the multi-year period of tree growth, the variables needed for experiments in canopy type training are hardly accessible through field measurements. In this paper, we concentrated on exploring the relationship between branching angle and light interception using a three-dimensional (3D) canopy model in loquat (Eriobotrya japonica Lindl). First, detailed 3D models of loquat trees were built by integrating branch and organ models. Second, the morphological models of different loquat trees were constructed by interactive editing. Third, the 3D individual-tree modeling software LSTree integrated with the OpenGL shadow technique, a radiosity model and a modified rectangular hyperbola model was used to calculate the silhouette to total area ratio, the distribution of photosynthetically active radiation within canopies and the net photosynthetic rate, respectively. Finally, the influence of loquat tree organ organization on the light interception of the trees was analyzed with different parameters. If the single branch angle between the level 2 scaffold branch and trunk is approximately 15° and the angles among the level 2 scaffold branches range from 60 to 90°, then a better light distribution can be obtained. The results showed that the branching angle has a significant impact on light interception, which is useful for grower manipulation of trees, e.g., shoot bending (scaffold branch angle). Based on this conclusion, a reasonable tree structure was selected for intercepting light. This quantitative simulation and analytical method provides a new digital and visual method that can aid in the design of tree architecture
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