Model anisotropic quantum Hall states

Model quantum Hall states including Laughlin, Moore-Read and Read-Rezayi states are generalized into appropriate anisotropic form. The generalized states are exact zero-energy eigenstates of corresponding anisotropic two- or multi-body Hamiltonians, and explicitly illustrate the existence of geometric degrees of in the fractional quantum Hall effect. These generalized model quantum Hall states can provide a good description of the quantum Hall system with anisotropic interactions. Some numeric results of these anisotropic quantum Hall states are also presented.Comment: 10 pages, 5 figure

Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Moreover, these measurements can help to include the effect of shallow groundwater on surface energy balance within land surface models and climate studies, which broadens the methods that yield more reliable and informative results. To examine the capacity of MODIS in detecting the effect of shallow groundwater on land surface temperature and the surface energy balance in an area within Al-Balikh River basin in northern Syria, we studied the interrelationship between in-situ measured water table depths and land surface temperatures measured by MODIS. We, also, used the Surface Energy Balance System (SEBS) to calculate surface energy fluxes, evaporative fraction and daily evaporation, and inspected their relationships with water table depths. We found out that the daytime temperature increased while the nighttime temperature decreased when the depth of the water table increased. And, when the water table depth increased, net radiation, latent and ground heat fluxes, evaporative fraction and daily evaporation decreased, while sensible heat flux increased. This concords with the findings of a companion paper (Alkhaier et al., 2012). The observed clear relationships were the result of meeting both conditions that were concluded in the companion paper, i.e. high potential evaporation and big contrast in day-night temperature. Moreover, the prevailing conditions in this study area helped SEBS to yield accurate estimates. Under bare soil conditions and under the prevailing weather conditions, we conclude that MODIS is suitable for detecting the effect of shallow groundwater because it has proper imaging times and adequate sensor accuracy; nevertheless, its coarse spatial resolution is disadvantageous

Theory for Gossamer and Resonating Valence Bond Superconductivity

We use an effective Hamiltonian for two-dimensional Hubbard model including an antiferromagnetic spin-spin coupling term to study recently proposed gossamer superconductivity. We formulate a renormalized mean field theory to approximately take into account the strong correlation effect in the partially projected Gutzwiller wavefucntions. At the half filled, there is a first order phase transition to separate a Mott insulator at large Coulomb repulsion U from a gossamer superconductor at small U. Away from the half filled,the Mott insulator is evolved into an resonating valence bond state, which is adiabatically connected to the gossamer superconductor.Comment: 10 pages, 13 figure

Effects of hydrogen sulfide (H2S) on respiration control of state 3/4 in mitochondria from bovine heart

Hydrogen sulfide (H2S) could availably regulate electron transport in the inner membrane of mitochondria from bovine heart when succinate as substrate and rotenone as complex I inhibitor at 37°C were used. H2S increased to a certain extent the respiratory rate of state 4. It also increased first and then decreased the respiratory rate of state 3, respiratory control ratio and ADP/O ratio. In addition, it quicken first and then delayed recovery time from state 3 to state 4. The effects of H2S as aforementioned in normoxic condition were more obvious than those in hypoxic condition. Experimental results indicated that more than 10 µM H2S brought about uncoupling of mitochondrial electron transport and the opening of mitochondrial KATP channel located in complex III-IV, and less than 10 µM H2S unexpectedly facilitated this course, which might be via sulfide-quinone oxidoreductase. The finding that H2S was closely related with sulfide-quinone oxidoreductase, however, requires in depth investigation.Key words: Respiration, hydrogen sulfide, mitochondria, bovine heart

First- and Second-Order Phase Transitions, Fulde-Ferrel Inhomogeneous State and Quantum Criticality in Ferromagnet/Superconductor Double Tunnel Junctions

First- and second-order phase transitions, Fulde-Ferrel (FF) inhomogeneous superconducting (SC) state and quantum criticality in ferromagnet/superconductor/ferromagnet double tunnel junctions are investigated. For the antiparallel alignment of magnetizations, it is shown that a first-order phase transition from the homogeneous BCS state to the inhomogeneous FF state occurs at a certain bias voltage $V^{\ast}$; while the transitions from the BCS state and the FF state to the normal state at $V_{c}$ are of the second-order. A phase diagram for the central superconductor is presented. In addition, a quantum critical point (QCP), $$, is identified. It is uncovered that near the QCP, the SC gap, the chemical potential shift induced by the spin accumulation, and the difference of free energies between the SC and normal states vanish as $$ with the quantum critical exponents $z\nu =1/2$, 1 and 2, respectively. The tunnel conductance and magnetoresistance are also discussed.Comment: 5 pages, 4 figures, Phys. Rev. B 71, 144514 (2005

TSPO expression in brain tumours: is TSPO a target for brain tumour imaging?

Positron emission tomography (PET) alone or in combination with MRI is increasingly assuming a central role in the development of diagnostic and therapeutic strategies for brain tumours with the aim of addressing tumour heterogeneity, assisting in patient stratification, and contributing to predicting treatment response. The 18 kDa translocator protein (TSPO) is expressed in high-grade gliomas, while its expression is comparatively low in normal brain. In addition, the evidence of elevated TSPO in neoplastic cells has led to studies investigating TSPO as a transporter of anticancer drugs for brain delivery and a selective target for tumour tissue. The TSPO therefore represents an ideal candidate for molecular imaging studies. Knowledge of the biology of TSPO in normal brain cells, in-depth understanding of TSPO functions and biodistribution in neoplastic cells, accurate methods for quantification of uptake of TSPO tracers and pharmacokinetic data regarding TSPO-targeted drugs are required before introducing TSPO PET and TSPO-targeted treatment in clinical practice. In this review, we will discuss the impact of preclinical PET studies and the application of TSPO imaging in human brain tumours, the advantages and disadvantages of TSPO imaging compared to other imaging modalities and other PET tracers, and pathology studies on the extent and distribution of TSPO in gliomas. The suitability of TSPO as molecular target for treatment of brain tumours will also be the appraised

Evaluation of Embryotoxicity of Radix scutellariae Based on Embryonic Stem Test

Purpose: To determine the potential embryotoxicity of Radix scutellariae (RS) extract using an embryonic stem cell test (EST) and to evaluate its effect on the differentiation of mouse embryonic stem (ES) cells.Methods: All the test samples were obtained by water extraction method. The embryotoxicity of RS was assessed with cytotoxicity assays, namely, embryonic stem (ES) cells (IC50ES) and 3T3 fibroblasts (IC503T3), as well as cardiac differentiation inhibition assay (ID50ES). The expression of specific genes and proteins was analyzed by quantitative reverse transcription – polymerase chain reaction (RT-PCR) and Western blot.Results: RS was weakly embryotoxic with IC50ES, IC503T3 and ID50ES of 0.1524, 0.1061, and 0.4169 mg/ml, respectively. Also RS had discordant effects on the expression of tissue-specific genes and proteins in three germ layers, promoting differentiation of the ectoderm (⋆p < 0.05; ⋆⋆p < 0.01) and endoderm (⋆p < 0.05; ⋆⋆p < 0.01; ⋆⋆⋆p < 0.001), while inhibiting mesoderm differentiation (⋆p < 0.05; ⋆⋆p < 0.01; ⋆⋆⋆p < 0.001). The effect of RS on the embryonic development of the three germ layers was concentration-dependent.Conclusion: These results indicate that RS possesses weak embryotoxicity. The variability in the effects of RS may be responsible for its weak embryotoxicity.Keywords: Embryonic stem test, Radix scutellariae, Embryotoxicity, Cardiac differentiation inhibition assay, Ectoderm, Endoderm, Mesoder

Exploiting Cognitive Structure for Adaptive Learning

Adaptive learning, also known as adaptive teaching, relies on learning path recommendation, which sequentially recommends personalized learning items (e.g., lectures, exercises) to satisfy the unique needs of each learner. Although it is well known that modeling the cognitive structure including knowledge level of learners and knowledge structure (e.g., the prerequisite relations) of learning items is important for learning path recommendation, existing methods for adaptive learning often separately focus on either knowledge levels of learners or knowledge structure of learning items. To fully exploit the multifaceted cognitive structure for learning path recommendation, we propose a Cognitive Structure Enhanced framework for Adaptive Learning, named CSEAL. By viewing path recommendation as a Markov Decision Process and applying an actor-critic algorithm, CSEAL can sequentially identify the right learning items to different learners. Specifically, we first utilize a recurrent neural network to trace the evolving knowledge levels of learners at each learning step. Then, we design a navigation algorithm on the knowledge structure to ensure the logicality of learning paths, which reduces the search space in the decision process. Finally, the actor-critic algorithm is used to determine what to learn next and whose parameters are dynamically updated along the learning path. Extensive experiments on real-world data demonstrate the effectiveness and robustness of CSEAL.Comment: Accepted by KDD 2019 Research Track. In Proceedings of the 25th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining (KDD'19