1,538 research outputs found
A STOCHASTIC SIMULATION-BASED HYBRID INTERVAL FUZZY PROGRAMMING APPROACH FOR OPTIMIZING THE TREATMENT OF RECOVERED OILY WATER
In this paper, a stochastic simulation-based hybrid interval fuzzy programming (SHIFP) approach
is developed to aid the decision-making process by solving fuzzy linear optimization problems.
Fuzzy set theory, probability theory, and interval analysis are integrated to take into account the
effect of imprecise information, subjective judgment, and variable environmental conditions. A
case study related to oily water treatment during offshore oil spill clean-up operations is conducted
to demonstrate the applicability of the proposed approach. The results suggest that producing a
random sequence of triangular fuzzy numbers in a given interval is equivalent to a normal
distribution when using the centroid defuzzification method. It also shows that the defuzzified
optimal solutions follow the normal distribution and range from 3,000-3,700 tons, given the
budget constraint (CAD 110,000-150,000). The normality seems to be able to propagate
throughout the optimization process, yet this interesting finding deserves more in-depth study
and needs more rigorous mathematical proof to validate its applicability and feasibility. In
addition, the optimal decision variables can be categorized into several groups with different
probability such that decision makers can wisely allocate limited resources with higher
confidence in a short period of time. This study is expected to advise the industries and
authorities on how to distribute resources and maximize the treatment efficiency of oily
water in a short period of time, particularly in the context of harsh environments
Radio-frequency spectroscopy of weakly bound molecules in spin-orbit coupled atomic Fermi gases
We investigate theoretically radio-frequency spectroscopy of weakly bound
molecules in an ultracold spin-orbit-coupled atomic Fermi gas. We consider two
cases with either equal Rashba and Dresselhaus coupling or pure Rashba
coupling. The former system has been realized very recently at Shanxi
University [Wang et al., arXiv:1204.1887] and MIT [Cheuk et al.,
arXiv:1205.3483]. We predict realistic radio-frequency signals for revealing
the unique properties of anisotropic molecules formed by spin-orbit coupling.Comment: 11 pages, 7 figure
医学生创新思维和临床实践能力培养的医学遗传学教学改革与实践研究
To improve medical students' autonomous learning, clinical thinking and problem analysis and problem solving, and clinical practice skills, TBL teaching and clinical practice and case analysis are introduced in medical genetics teaching. The students could promote autonomous learning and independent study through consulting data, group discussion, and social practice. The whole process of heuristic, participatory teaching, could fully mobilize the enthusiasm and initiative of students, making students become the subject of learning, and interaction between teachers and students, students interaction and group discussion, as one of the social practice teaching mode. In this teaching model, students get horizontal contact of knowledge, vertical infiltration, which make the basic medical knowledge and clinical medical knowledge effectively integrate, achieving good teaching effect.为提高医学生自主学习、临床思维、分析问题和解决问题及临床实践技能,将TBL教学法及临床实践和病例分析引入医学遗传学教学中,学生通过查阅资料、团队讨论、社会实践等途径自主学习、自主研究,整个教学过程中贯穿着启发式、参与式教学,充分调动了学生学习的积极性和主观能动性,让学生成为学习的主体,集师生互动、同学互动和团队讨论、社会实践为一体的教学模式。在该教学模式中,学生对所学知识进行横向联系,纵向渗透,使基础医学知识和临床医学知识有效整合,取得了良好的教学效果
Fermi Gases with Synthetic Spin-Orbit Coupling
We briefly review recent progress on ultracold atomic Fermi gases with
different types of synthetic spin-orbit coupling, including the one-dimensional
(1D) equal weight Rashba-Dresselhaus and two-dimensional (2D) Rasbha spin-orbit
couplings. Theoretically, we show how the single-body, two-body and many-body
properties of Fermi gases are dramatically changed by spin-orbit coupling. In
particular, the interplay between spin-orbit coupling and interatomic
interaction may lead to several long-sought exotic superfluid phases at low
temperatures, such as anisotropic superfluid, topological superfluid and
inhomogeneous superfluid. Experimentally, only the first type - equal weight
combination of Rasbha and Dresselhaus spin-orbit couplings - has been realized
very recently using a two-photon Raman process. We show how to characterize a
normal spin-orbit coupled atomic Fermi gas in both non-interacting and
strongly-interacting limits, using particularly momentum-resolved
radio-frequency spectroscopy. The experimental demonstration of a
strongly-interacting spin-orbit coupled Fermi gas opens a promising way to
observe various exotic superfluid phases in the near future.Comment: 35 pages, 29 fiugres. Invited review paper for Annual Review of Cold
Atoms and Molecules (Volume 2) (2014
Phase Separation in two-Species Atomic Bose-Einstein Condensate with Interspecies Feshbach Resonance
We consider a mixture of two-species atomic Bose-Einstein codensates coupled
to a bound molecular state at zero temperature via interspecies Feshbach
resonance. The interspecies Feshbach coupling precludes the possibility of
doubly mixed phases while enables not only the pure molecular superfluid but
also the pure atomic superfluids to exist as distinct phases. We show that this
system is able to support a rich set of phase separations, including that
between two distinct mixed atom-molecule phases. We pay particular attention to
the effects of the Feschbach coupling and the particle collisions on the
miscibility of this multi-component condensate system.Comment: 9 pages, 3 figure
Understanding the quantum Rabi ring using analogies to quantum magnetism
We map a quantum Rabi ring, consisting of cavities arranged in a ring
geometry, into an effective magnetic model containing the XY exchange and the
Dzyaloshinskii Moriya (DM) interactions. The analogue of the latter is induced
by an artificial magnetic field, which modulates photon hopping between
nearest-neighbor cavities with a phase. The mean-field behavior of both systems
is almost identical, facilitating the description of the different phases in
the quantum optical model through simple arguments of competing magnetic
interactions. For the square geometry () the rich phase diagram exhibits
three superradiant phases denoted as ferro-superradiant, antiferro-superradiant
and chiral superradiant. In particular, the DM interaction is responsible for
the chiral phase in which the energetically degenerate configurations of the
order parameters are similar to the in-plane magnetizations of skyrmions with
different helicities. The antiferro-superradiant phase is suppressed in the
triangle geometry () as geometric frustration contributes to stabilize the
chiral phase even for small values of the DM interaction. The chiral phases for
odd and even show a different scaling behavior close to the phase
transition. The equivalent behavior on both systems opens the possibility of
simulating chiral magnetism in a few-body quantum optical platform, as well as
understanding one system using the insights gained from the other.Comment: 14 pages, 6 figure
Syntaxin 1B Mediates Berberine’s Roles in Epilepsy-Like Behavior in a Pentylenetetrazole-Induced Seizure Zebrafish Model
Epilepsy is a neuronal dysfunction syndrome characterized by transient and diffusely abnormal discharges of neurons in the brain. Previous studies have shown that mutations in the syntaxin 1b (stx1b) gene cause a familial, fever-associated epilepsy syndrome. It is unclear as to whether the stx1b gene also correlates with other stimulations such as flashing and/or mediates the effects of antiepileptic drugs. In this study, we found that the expression of stx1b was present mainly in the brain and was negatively correlated with seizures in a pentylenetetrazole (PTZ)-induced seizure zebrafish model. The transcription of stx1b was inhibited by PTZ but rescued by valproate, a broad-spectrum epilepsy treatment drug. In the PTZ–seizure zebrafish model, stx1b knockdown aggravated larvae hyperexcitatory swimming and prompted abnormal trajectory movements, particularly under lighting stimulation; at the same time, the expression levels of the neuronal activity marker gene c-fos increased significantly in the brain. In contrast, stx1b overexpression attenuated seizures and decreased c-fos expression levels following PTZ-induced seizures in larvae. Thus, we speculated that a deficiency of stx1b gene expression may be related with the onset occurrence of clinical seizures, particularly photosensitive seizures. In addition, we found that berberine (BBR) reduced larvae hyperexcitatory locomotion and abnormal movement trajectory in a concentration-dependent manner, slowed down excessive photosensitive seizure-like swimming, and assisted in the recovery of the expression levels of STX1B. Under the downregulation of STX1B, BBR’s roles were limited: specifically, it only slightly regulated the levels of the two genes stx1b and c-fos and the hyperexcitatory motion of zebrafish in dark conditions and had no effect on the overexcited swimming behavior seen in conjunction with lighting stimulation. These findings further demonstrate that STX1B protein levels are negatively correlated with a seizure and can decrease the sensitivity of the photosensitive response in a PTZ-induced seizure zebrafish larvae; furthermore, STX1B may partially mediate the anticonvulsant effect of BBR. Additional investigation regarding the relationship between STX1B, BBR, and seizures could provide new cues for the development of novel anticonvulsant drugs
Comparative Study of Different Diets-Induced NAFLD Models of Zebrafish
Dietary composition has important impact on nonalcoholic fatty liver disease (NAFLD). The purpose of this study was to explore the relationship between NAFLD and major dietary components using zebrafish larvae fed different diets. Zebrafish larvae fed with high cholesterol (HC), high fructose (HF) and extra feeding (EF) diets for 10 days displayed varying degrees steatosis. The incidence and degree of steatosis were the most severe in the EF group. A HC diet severely promoted lipid deposits in the caudal vein. The triglyceride and glucose contents of zebrafish significantly increased in the HF and EF groups compared with the control group. Moreover, the mRNA expression of oxidative stress gene gpx1a, endoplasmic reticulum stress genes ddit3 and grp78, inflammatory genes tnfa, glucose metabolism genes irs2, glut1 and glut2, and lipid metabolism genes cidec, chrebp, ppara and cpt1a were significantly increased in the HF group. The HC diet was associated with upregulation of grp78, and downregulation of irs2, glut1 and glut2. The mRNA expression of lipogenesis and glucose metabolism associated genes were decreased in the EF group. In addition, the autophagy associated genes atg3, atg5, atg7, and atg12, and protein expression of ATG3 and LC3BII were reduced and P62 were elevated in the HC group. We also performed comparative transcriptome analysis of the four groups. A total of 2,492 differentially expressed genes were identified, and 24 statistically significant pathways were enriched in the diet treatment groups. This study extends our understanding of the relationships between diet ingredients and host factors that contribute to the pathogenesis of NAFLD, which may provide new ideas for the treatment of NAFLD
Radio-frequency spectroscopy of a strongly interacting spin-orbit coupled Fermi gas
We investigate experimentally and theoretically radio-frequency spectroscopy
and pairing of a spin-orbit-coupled Fermi gas of K atoms near a Feshbach
resonance at G. Experimentally, the integrated spectroscopy is
measured, showing characteristic blue and red shifts in the atomic and
molecular responses, respectively, with increasing spin-orbit coupling.
Theoretically, a smooth transition from atomic to molecular responses in the
momentum-resolved spectroscopy is predicted, with a clear signature of
anisotropic pairing at and below resonance. Our many-body prediction agrees
qualitatively well with the observed spectroscopy near the Feshbach resonance.Comment: 7 pages, 4 figures. Supercedes 1302.055
- …