1,934 research outputs found
Orbital density wave induced by electron-lattice coupling in orthorhombic iron pnictides
In this paper we explore the magnetic and orbital properties closely related
to a tetragonal-orthorhombic structural phase transition in iron pnictides
based on both two- and five-orbital Hubbard models. The electron-lattice
coupling, which interplays with electronic interaction, is self-consistently
treated. Our results reveal that the orbital polarization stabilizes the spin
density wave (SDW) order in both tetragonal and orthorhombic phases. However,
the ferro-orbital density wave (F-ODW) only occurs in the orthorhombic phase
rather than in the tetragonal one. Magnetic moments of Fe are small in the
intermediate Coulomb interaction region for the striped antiferromangnetic
phase in the realistic five orbital model. The anisotropic Fermi surface in the
SDW/ODW orthorhombic phase is well in agreement with the recent angle-resolved
photoemission spectroscopy experiments. These results suggest a scenario that
the magnetic phase transition is driven by the ODW order mainly arising from
the electron-lattice coupling.Comment: 21 pages, 10 figure
CLIP-Hand3D: Exploiting 3D Hand Pose Estimation via Context-Aware Prompting
Contrastive Language-Image Pre-training (CLIP) starts to emerge in many
computer vision tasks and has achieved promising performance. However, it
remains underexplored whether CLIP can be generalized to 3D hand pose
estimation, as bridging text prompts with pose-aware features presents
significant challenges due to the discrete nature of joint positions in 3D
space. In this paper, we make one of the first attempts to propose a novel 3D
hand pose estimator from monocular images, dubbed as CLIP-Hand3D, which
successfully bridges the gap between text prompts and irregular detailed pose
distribution. In particular, the distribution order of hand joints in various
3D space directions is derived from pose labels, forming corresponding text
prompts that are subsequently encoded into text representations.
Simultaneously, 21 hand joints in the 3D space are retrieved, and their spatial
distribution (in x, y, and z axes) is encoded to form pose-aware features.
Subsequently, we maximize semantic consistency for a pair of pose-text features
following a CLIP-based contrastive learning paradigm. Furthermore, a
coarse-to-fine mesh regressor is designed, which is capable of effectively
querying joint-aware cues from the feature pyramid. Extensive experiments on
several public hand benchmarks show that the proposed model attains a
significantly faster inference speed while achieving state-of-the-art
performance compared to methods utilizing the similar scale backbone.Comment: Accepted In Proceedings of the 31st ACM International Conference on
Multimedia (MM' 23
Physiological Responses in a Variable Environment: Relationships between Metabolism, Hsp and Thermotolerance in an Intertidal-Subtidal Species
Physiological responses to temperature reflect the evolutionary adaptations of organisms to their thermal environment and the capability of animals to tolerate thermal stress. Contrary to conventional metabolism theory, increasing environmental temperatures have been shown to reduce metabolic rate in rocky–eulittoral-fringe species inhabiting highly variable environments, possibly as a strategy for energy conservation. To study the physiological adaptations of an intertidal-subtidal species to the extreme and unpredictable heat stress of the intertidal zone, oxygen consumption rate and heat shock protein expression were quantified in the sea cucumber Apostichopus japonicus. Using simulate natural temperatures, the relationship between temperature, physiological performance (oxygen consumption and heat shock proteins) and thermotolerance were assessed. Depression of oxygen consumption rate and upregulation of heat shock protein genes (hsps) occurred in sequence when ambient temperature was increased from 24 to 30°C. Large-scale mortality of the sea cucumber occurred when temperatures rose beyond 30°C, suggesting that the upregulation of heat shock proteins and mortality are closely related to the depression of aerobic metabolism, a phenomenon that is in line with the concept of oxygen- and capacity-limited thermal tolerance (OCLTT). The physiologically-related thermotolerance of this sea cucumber should be an adaptation to its local environment
Molecular cloning and characterization of a novel Cys2/His2-type zinc finger protein gene from chrysanthemum
A novel member of the Cys2/His2-type zinc finger protein gene family, designated DgZFP3, was isolated from chrysanthemum by rapid amplification of cDNA ends (RACE). The DgZFP3 encodes a protein of 248 amino acids, including two conserved Cys2/His2-type zinc finger motifs with a plant-specific QALGGH motif in each zinc finger domain, a B-box (KXKRSKRXR) domain in the N-terminal region as a putative nuclear localization signal (NLS), a L-box (EXEXXAXCLXXL) and an EAR-box (DLNL) at C-terminus. Subcellular localization showed the presence of DgZFP3 in the nucleus. The transcript of DgZFP3 was enriched in roots and leaves than in stems and flowers of the adult chrysanthemum plants. Expression patterns revealed that DgZFP3 was strongly induced by NaCl, drought, cold and abscisic acid (ABA) treatment in the seedlings. We argued that DgZFP3 is a new member of the Cys2/His2-type zinc finger protein gene family, and it may be involved in the plant responses to various stresses.Keywords: Chrysanthemum, DgZFP3, gene expression, Cys2/His2-type zinc finger protei
Analytic solutions of relativistic dissipative spin hydrodynamics with radial expansion in Gubser flow
We have derived the analytic solutions of dissipative relativistic spin
hydrodynamics with Gubser expansion. Following the standard strategy of
deriving the solutions in a Gubser flow, we take the Weyl rescaling and obtain
the energy-momentum and angular momentum conversation equations in the
space-time. We then derive the analytic solutions of
spin density, spin potential and other thermodynamic in
space-time and transform them back into Minkowski
space-time . In the Minkowski space-time, the spin density
and spin potential including the information of radial expansion decay as and in large limit, with
being proper time and being the characteristic length of the system,
respectively. Moreover, we observe the non-vanishing spin corrections to the
energy density and other dissipative terms in the Belinfante form of
dissipative spin hydrodynamics. Our results can also be used as test beds for
future simulations of relativistic dissipative spin hydrodynamics.Comment: 28 pages; 1 table and 1 figure are adde
GammaE: Gamma Embeddings for Logical Queries on Knowledge Graphs
Embedding knowledge graphs (KGs) for multi-hop logical reasoning is a
challenging problem due to massive and complicated structures in many KGs.
Recently, many promising works projected entities and queries into a geometric
space to efficiently find answers. However, it remains challenging to model the
negation and union operator. The negation operator has no strict boundaries,
which generates overlapped embeddings and leads to obtaining ambiguous answers.
An additional limitation is that the union operator is non-closure, which
undermines the model to handle a series of union operators. To address these
problems, we propose a novel probabilistic embedding model, namely Gamma
Embeddings (GammaE), for encoding entities and queries to answer different
types of FOL queries on KGs. We utilize the linear property and strong boundary
support of the Gamma distribution to capture more features of entities and
queries, which dramatically reduces model uncertainty. Furthermore, GammaE
implements the Gamma mixture method to design the closed union operator. The
performance of GammaE is validated on three large logical query datasets.
Experimental results show that GammaE significantly outperforms
state-of-the-art models on public benchmarks
Causality and stability analysis for the minimal causal spin hydrodynamics
We perform the linear analysis of causality and stability for a minimal
extended spin hydrodynamics up to second order of the gradient expansion. The
first order spin hydrodynamics, with a rank-3 spin tensor being antisymmetric
for only the last two indices, are proved to be acausal and unstable. We then
consider the minimal causal spin hydrodynamics up to second order of the
gradient expansion. We derive the necessary causality and stability conditions
for this minimal causal spin hydrodynamics. Interestingly, the satisfaction of
the stability conditions relies on the equations of state for the spin density
and chemical potentials. Moreover, different with the conventional relativistic
dissipative hydrodynamics, the stability of the theory seems to be broken at
the finite wave-vector when the stability conditions are fulfilled at small and
large wave-vector limits. It implies that the behavior in small and large
wave-vector limits may be insufficient to determine the stability conditions
for spin hydrodynamics in linear mode analysis.Comment: 45 pages, 2 figures, typos corrected, published versio
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