Multiple flat bands and localized states in photonic super-Kagome lattices

We demonstrate multiple flat bands and compact localized states (CLSs) in a photonic super-Kagome lattice (SKL) that exhibits coexistence of singular and nonsingular flat bands within its unique band structure. Specifically, we find that the upper two flat bands of an SKL are singular - characterized by singularities due to band touching with their neighboring dispersive bands at the Brillouin zone center. Conversely, the lower three degenerate flat bands are nonsingular, and remain spectrally isolated from other dispersive bands. The existence of such two distinct types of flat bands is experimentally demonstrated by observing stable evolution of the CLSs with various geometrical shapes in a laser-written SKL. We also discuss the classification of the flat bands in momentum space, using band-touching singularities of the Bloch wave functions. Furthermore, we validate this classification in real space based on unit cell occupancy of the CLSs in a single SKL plaquette. These results may provide insights for the study of flatband transport, dynamics, and nontrivial topological phenomena in other relevant systems.Comment: 5 pages,4 figure

Phylogenetics and Biogeography of Lilium ledebourii from the Hyrcanian Forest

ilium ledebourii (Baker) Boiss is one of the most endangered lilies, restricted to only a few small and fragmented areas in the Hyrcanian forest. This study aimed at evaluating the taxonomy of this unique Iranian lily and reconstructing divergence time from other species of the genus Lilium to address the role of this region in its diversification. Phylogenetic trees based on nuclear ITS and chloroplastic matK strongly supported the monophyly of the genus Lilium and division into subclades hardly matching prior morphological classifications. Biogeographic analyses using S-DIVA revealed East Asia as the ancestral range from where Lilium presented a multidirectional expansion towards North America, West-Central Asia, North Asia, and Europe. Diverging from ancestral Lilium during the beginning of Eocene (50 Ma; 95% HDP: 68.8–36.8). Specific members of Lilium colonized Iran (Western Asia) separated from the Clade IV (West-Central Asia and Europe lineage), and then yielded the Iranian L.ledebourri. Accordingly, the north of Iran appears to have promoted both long-term persistence and migration of Lily species from Asia to the Europe

Shoot Organogenesis and Plant Regeneration from Leaf Explants of Lysionotus serratus

The gesneriaceous perennial plant, Lysionotus serratus, has been used in traditional Chinese medicine. It also has a great development potential as an ornamental plant with its attractive foliage and beautiful flowers. An efficient propagation and regeneration system via direct shoot organogenesis from leaf explant was established in this study. High active cytokinin (6-benzyladenine (BA) or thidiazuron (TDZ)) was effective for direct organogenesis of initial induction. Murashige and Skoog (MS) growth media containing 0.5 mg L−1 BA alone or with combination of 0.1 mg L−1  α-Naphthaleneacetic acid (NAA) were the most effective for shoot proliferation. High BA concentration (1.0 mg L−1) in the media caused high percentage of vitrified shoots though they introduced high shoot proliferation rate. Histological observation indicated that adventitious shoot regeneration on the medium containing 0.5 mg L−1 BA alone occurred directly from leaf epidermal cells without callus formation. Regenerated shoots rooted well on medium containing half-strength MS medium with 0.5 mg L−1 indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA), and the plantlets successfully acclimatized and grew vigorously in the greenhouse with a 94.2% and 92.1% survival rate

Realization of robust boundary modes and non-contractible loop states in photonic Kagome lattices

Corbino-geometry has well-known applications in physics, as in the design of graphene heterostructures for detecting fractional quantum Hall states or superconducting waveguides for illustrating circuit quantum electrodynamics. Here, we propose and demonstrate a photonic Kagome lattice in the Corbino-geometry that leads to direct observation of non-contractible loop states protected by real-space topology. Such states represent the "missing" flat-band eigenmodes, manifested as one-dimensional loops winding around a torus, or lines infinitely extending to the entire flat-band lattice. In finite (truncated) Kagome lattices, however, line states cannot preserve as they are no longer the eigenmodes, in sharp contrast to the case of Lieb lattices. Using a continuous-wave laser writing technique, we experimentally establish finite Kagome lattices with desired cutting edges, as well as in the Corbino-geometry to eliminate edge effects. We thereby observe, for the first time to our knowledge, the robust boundary modes exhibiting self-healing properties, and the localized modes along toroidal direction as a direct manifestation of the non-contractible loop states

Automatic and Selective Single Cell Manipulation in a Pressure-Driven Microfluidic Lab-On-Chip Device

A microfluidic lab-on-chip device was developed to automatically and selectively manipulate target cells at the single cell level. The device is composed of a microfluidic chip, mini solenoid valves with negative-pressurized soft tubes, and a LabView®-based data acquisition device. Once a target cell passes the resistive pulse sensing gate of the microfluidic chip, the solenoid valves are automatically actuated and open the negative-pressurized tubes placed at the ends of the collecting channels. As a result, the cell is transported to that collecting well. Numerical simulation shows that a 0.14 mm3 volume change of the soft tube can result in a 1.58 mm/s moving velocity of the sample solution. Experiments with single polystyrene particles and cancer cells samples were carried out to demonstrate the effectiveness of this method. Selectively manipulating a certain size of particles from a mixture solution was also achieved. Due to the very high pressure-driven flow switching, as many as 300 target cells per minute can be isolated from the sample solution and thus is particularly suitable for manipulating very rare target cells. The device is simple, automatic, and label-free and particularly suitable for isolating single cells off the chip one by one for downstream analysis

Biodiversity arks in the Anthropocene

The Anthropocene proposal suggested that the Earth may have entered a new geological epoch, in which human activity and climate change are influencing the environment at global scale. Arrival of the Anthropocene is bringing an unprecedented challenge to the biodiversity that is essential to humans, and enhancing many benefits of nature to human being. However, biodiversity loss is aggravating in the rhythm of inevitable change in the Anthropocene, and the adaptation of biodiversity to the anthropogenic disturbance seems unable to keep pace with the human activity and climate change. Therefore, re-examination of the assumptions and practices upon the current conservation endeavor are needed. We suggested that biodiversity conservation should be paid more attention to the response from biodiversity to the human activity and climate change in the Anthropocene. Thus, the concept of biodiversity arks in the Anthropocene is proposed, that is, biodiversity arks in the Anthropocene are the areas where vulnerable biodiversity is sheltered to alleviate human activity and buffered from climate change under the anthropogenic disturbance. The concept should be implemented for biodiversity conservation to fill gaps between our knowledge and build on successful conservation and sustainability in the Anthropocene. It will be certainly important to conservation policy instruction and management under climate change, especially the implementation of climate buffering zones preserving biodiversity in the face of warming climate

Host Cyanobacteria Killing by Novel Lytic Cyanophage YongM: A Protein Profiling Analysis

Cyanobacteria are autotrophic prokaryotes that can proliferate robustly in eutrophic waters through photosynthesis. This can lead to outbreaks of lake “water blooms”, which result in water quality reduction and environmental pollution that seriously affect fisheries and aquaculture. The use of cyanophages to control the growth of cyanobacteria is an important strategy to tackle annual cyanobacterial blooms. YongM is a novel lytic cyanophage with a broad host spectrum and high efficiency in killing its host, cyanobacteria FACHB-596. However, changes in cyanophage protein profile during infestation and killing of the host remains unknown. To characterize the proteins and its regulation networks involved in the killing of host cyanobacteria by YongM and evaluate whether this strain YongM could be used as a chassis for further engineering to be a powerful tool in dealing with cyanobacterial blooms, we herein applied 4D label-free high-throughput quantitative proteomics to analyze differentially expressed proteins (DEPs) involved in cyanobacteria host response infected 1 and 8 h with YongM cyanophage. Metabolic pathways, such as photosynthesis, photosynthesis-antennal protein, oxidative phosphorylation, ribosome, carbon fixation, and glycolysis/glycol-isomerization were significantly altered in the infested host, whereas DEPs were associated with the metabolic processes of photosynthesis, precursor metabolites, energy production, and organic nitrogen compounds. Among these DEPs, key proteins involved in YongM-host interaction may be photosystem I P700 chlorophyll-a apolipoprotein, carbon dioxide concentration mechanism protein, cytochrome B, and some YongM infection lysis-related enzymes. Our results provide comprehensive information of protein profiles during the invasion and killing of host cyanobacteria by its cyanophage, which may shed light on future design and manipulation of artificial cyanophages against water blooms