625 research outputs found
Nanoantennas and Nanoradars: The Future of Integrated Sensing and Communication at the Nanoscale
Nanoantennas, operating at optical frequencies, are a transformative
technology with broad applications in 6G wireless communication, IoT, smart
cities, healthcare, and medical imaging. This paper explores their fundamental
aspects, applications, and advancements, aiming for a comprehensive
understanding of their potential in various applications. It begins by
investigating macroscopic and microscopic Maxwell's equations governing
electromagnetic wave propagation at different scales. The study emphasizes the
critical role of Surface Plasmon Polariton (SPP) wave propagation in enhancing
light-matter interactions, contributing to high data rates, and enabling
miniaturization. Additionally, it explores using two-dimensional materials like
graphene for enhanced control in terahertz communication and sensing. The paper
also introduces the employment of nanoantennas as the main building blocks of
Nano-scale Radar (NR) systems for the first time in the literature. NRs,
integrated with communication signals, promise accurate radar sensing for
nanoparticles inside a nano-channel, making them a potential future application
in integrated sensing and communication (ISAC) systems. These nano-scale radar
systems detect and extract physical or electrical properties of nanoparticles
through transmitting, receiving, and processing electromagnetic waves at
ultra-high frequencies in the optical range. This task requires nanoantennas as
transmitters/receivers/transceivers, sharing the same frequency band and
hardware for high-performance sensing and resolution
The human CNOT1-CNOT10-CNOT11 complex forms a structural platform for protein-protein interactions
The evolutionary conserved CCR4-NOT complex functions in the cytoplasm as the main mRNA deadenylase in both constitutive mRNA turnover and regulated mRNA decay pathways. The versatility of this complex is underpinned by its modular multi-subunit organization, with distinct structural modules actuating different functions. The structure and function of all modules are known, except for that of the N-terminal module. Using different structural approaches, we obtained high-resolution data revealing the architecture of the human N-terminal module composed of CNOT1, CNOT10, and CNOT11. The structure shows how two helical domains of CNOT1 sandwich CNOT10 and CNOT11, leaving the most conserved domain of CNOT11 protruding into solvent as an antenna. We discovered that GGNBP2, a protein identified as a tumor suppressor and spermatogenic factor, is a conserved interacting partner of the CNOT11 antenna domain. Structural and biochemical analyses thus pinpoint the N-terminal CNOT1-CNOT10-CNOT11 module as a conserved protein-protein interaction platform
Collaborative Broadcast in O(log log n) Rounds
We consider the multihop broadcasting problem for nodes placed uniformly
at random in a disk and investigate the number of hops required to transmit a
signal from the central node to all other nodes under three communication
models: Unit-Disk-Graph (UDG), Signal-to-Noise-Ratio (SNR), and the wave
superposition model of multiple input/multiple output (MIMO). In the MIMO
model, informed nodes cooperate to produce a stronger superposed signal. We do
not consider the problem of transmitting a full message nor do we consider
interference. In each round, the informed senders try to deliver to other nodes
the required signal strength such that the received signal can be distinguished
from the noise. We assume sufficiently high node density . In the unit-disk graph model, broadcasting needs
rounds. In the other models, we use an Expanding Disk Broadcasting Algorithm,
where in a round only triggered nodes within a certain distance from the
initiator node contribute to the broadcasting operation. This algorithm
achieves a broadcast in only rounds in the
SNR-model. Adapted to the MIMO model, it broadcasts within rounds. All bounds are asymptotically tight and hold with high
probability, i.e. .Comment: extended abstract accepted for ALGOSENSORS 201
Gravitational hedgehog, stringy hedgehog and stringy sphere
We investigate the solutions of Einstein equations such that a hedgehog
solution is matched to different exterior or interior solutions via a spherical
shell. In the case where both the exterior and the interior regions are
hedgehog solutions or one of them is flat, the resulting spherical shell
becomes a stringy shell. We also consider more general matchings and see that
in this case the shell deviates from its stringy character.Comment: 11 page
A Computational Approach for Designing Tiger Corridors in India
Wildlife corridors are components of landscapes, which facilitate the
movement of organisms and processes between intact habitat areas, and thus
provide connectivity between the habitats within the landscapes. Corridors are
thus regions within a given landscape that connect fragmented habitat patches
within the landscape. The major concern of designing corridors as a
conservation strategy is primarily to counter, and to the extent possible,
mitigate the effects of habitat fragmentation and loss on the biodiversity of
the landscape, as well as support continuance of land use for essential local
and global economic activities in the region of reference. In this paper, we
use game theory, graph theory, membership functions and chain code algorithm to
model and design a set of wildlife corridors with tiger (Panthera tigris
tigris) as the focal species. We identify the parameters which would affect the
tiger population in a landscape complex and using the presence of these
identified parameters construct a graph using the habitat patches supporting
tiger presence in the landscape complex as vertices and the possible paths
between them as edges. The passage of tigers through the possible paths have
been modelled as an Assurance game, with tigers as an individual player. The
game is played recursively as the tiger passes through each grid considered for
the model. The iteration causes the tiger to choose the most suitable path
signifying the emergence of adaptability. As a formal explanation of the game,
we model this interaction of tiger with the parameters as deterministic finite
automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201
Network 'small-world-ness': a quantitative method for determining canonical network equivalence
Background: Many technological, biological, social, and information networks fall into the broad class of 'small-world' networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction ('small/not-small') rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network's small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model-the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified.
Methodology/Principal Findings: We defined a precise measure of 'small-world-ness' S based on the trade off between high local clustering and short path length. A network is now deemed a 'small-world' if S. 1-an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process.
Conclusions/Significance: We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing
Evolution of the -ray strength function in neodymium isotopes
The experimental gamma-ray strength functions (gamma-SFs) of 142,144-151Nd
have been studied for gamma-ray energies up to the neutron separation energy.
The results represent a unique set of gamma-SFs for an isotopic chain with
increasing nuclear deformation. The data reveal how the low-energy enhancement,
the scissors mode and the pygmy dipole resonance evolve with nuclear
deformation and mass number. The data indicate that the mechanisms behind the
low-energy enhancement and the scissors mode are decoupled from each other.Comment: 14 pages and 10 figure
Control of developmentally primed erythroid genes by combinatorial co-repressor actions
How transcription factors (TFs) cooperate within large protein complexes to allow rapid modulation of gene expression during development is still largely unknown. Here we show that the key haematopoietic LIM-domain-binding protein-1 (LDB1) TF complex contains several activator and repressor components that together maintain an erythroid-specific gene expression programme primed for rapid activation until differentiation is induced. A combination of proteomics, functional genomics and in vivo studies presented here identifies known and novel co-repressors, most notably the ETO2 and IRF2BP2 proteins, involved in maintaining this primed state. The ETO2-IRF2BP2 axis, interacting with the NCOR1/SMRT co-repressor complex, suppresses the expression of the vast majority of archetypical erythroid genes and pathways until its decommissioning at the onset of terminal erythroid differentiation. Our experiments demonstrate that multimeric regulatory complexes feature a dynamic interplay between activating and repressing components that determines lineage-specific gene expression and cellular differentiation
- …