Holographic superconductor in a deformed four-dimensional STU model

In this paper, we consider deformed STU model in four dimensions including both electric and magnetic charges. Using AdS/CFT correspondence, we study holographic superconductor and obtain transport properties like electrical and thermal conductivities. We obtain transport properties in terms of the black hole magnetic charge and interpret it as magnetic monopole of dual field theory. We find that presence of magnetic charge is necessary to have maximum conductivities, and existence of magnetic monopole with a critical charge (137 e) to reach the maximum superconductivity is important. Also, we show that thermal conductivity increases with increasing of magnetic charge. It may be concluded that the origin of superconductivity is magnetic monopole.Comment: 19 pages, 8 Figures. Accepted for publication in EPJ

Aharonov-Bohm differential conductance modulation in defective metallic single-wall carbon nanotubes

Using a perturbative approach, the effects of the energy gap induced by the Aharonov-Bohm (AB) flux on the transport properties of defective metallic single-walled carbon nanotubes (MSWCNTs) are investigated. The electronic waves scattered back and forth by a pair of impurities give rise to Fabry-Perot oscillations which constitutes a coherent backscattering interference pattern (CBSIP). It is shown that, the CBSIP is aperiodically modulated by applying a magnetic field parallel to the nanotube axis. In fact, the AB-flux brings this CBSIP under control by an additional phase shift. As a consequence, the extrema as well as zeros of the CBSIP are located at the irrational fractions of the quantity $\Phi_\rho={\Phi}/{\Phi_0}$, where $\Phi$ is the flux piercing the nanotube cross section and $\Phi_{0}=h/e$ is the magnetic quantum flux. Indeed, the spacing between two adjacent extrema in the magneto-differential conductance (MDC) profile is decreased with increasing the magnetic field. The faster and higher and slower and shorter variations is then obtained by metallic zigzag and armchair nanotubes, respectively. Such results propose that defective metallic nanotubes could be used as magneto-conductance switching devices based on the AB effect.Comment: 11 pages, 4 figure

The feasibility of correlation between superconductivity and magnetic monopole: Establishment of semi-classical electrodynamics projection, TKH topological theory and dynamic vortex models

In this paper, a feasibility of semi-classical electromagnetic description together with experimental data, T-K-H topological and dynamic models and theory of vortex considered to justify the relation between superconductivity phenomena and magnetic monopole. We find that the electromagnetic energy of magnetic monopole is in agreement with vortex energy in topological theory and it can get close to thermal energy at room temperature. Indeed, these models suggest that the origin of the hot superconductivity may be magnetic monopoles with QM-Cl = 137 e (magnetic charge in classical approach) or QM-Q =137/2 e (magnetic charge in quantum approach), and the electrical conductivity is related to the mobile monopole or vortices. This research shows that the electrical permittivity ({\epsilon}) and magnetic permeability ({\mu}) of matter have a key role in the superconductive properties. We propose that this model may justify the hot superconductivity properties.Comment: 24 pages, 5 figure

Environmental, developmental, and genetic factors controlling root system architecture

A better understanding of the development and architecture of roots is essential to develop strategies to increase crop yield and optimize agricultural land use. Roots control nutrient and water uptake, provide anchoring and mechanical support and can serve as important storage organs. Root growth and development is under tight genetic control and modulated by developmental cues including plant hormones and the environment. This review focuses on root architecture and its diversity and the role of environment, nutrient, and water as well as plant hormones and their interactions in shaping root architecture

Evaluation of urban infrastructure on the basis of architectural design and landscape ecology

Ideology for landscape Ecology design must be maintained during the design of urban infrastructure and landscape ecology infrastructure can improve the quality of urban environment. Cities and biological complexes are the outcome of human interaction process in various aspects of social, economic, technological, etc., today, with the increasing development of knowledge; the human manipulation in the environment is increasing. And so humans by destroying the natural resources should face several problems, and that’s why different specialties are arise in order to solve the problems. Landscape architecture, including expertise that despite the long history of its use in human life has not much experience in academia environments as an independent field of study. Achievements of this specialty Activities, since it is rooted in nature by enjoying its talent in various aspects such as social issues, ecological and environmental role and could have a strong position for the city dwellers. This article due to needs of ecology design is focused on the effects of infrastructure production in terms of performance, the structure and materials, etc. And creating reasonable rules for ecological planning and landscape architecture in order to establish the foundations for the future development of ecology design methods for infrastructure.Keywords: landscape architecture; ecology; urban infrastructure

Effects of upper-body, lower-body, or combined resistance training on the ratio of follistatin and myostatin in middle-aged men.

PURPOSE:Due to the mechanistic role of myostatin and follistatin in modulating muscle mass, shifts in the follistatin to myostatin ratio (F:M) may help explain changes in muscular size in response to resistance training (RT). The present study examined whether differential responses in follistatin and myostatin occur based on the amount of active musculature in a RT program in middle-aged men. METHODS:Forty middle-aged men (age = 46.5 ± 3.1 years) were randomly assigned to 1 of 4 groups, upper-body RT (UB; n = 10), lower-body RT (LB; n = 10), combined RT (UB + LB; n = 10) or control (C; n = 10). The training protocol consisted of three exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 h after the final session of the training program. RESULTS:Muscle mass significantly increased (p < 0.05) following UB = 0.76 ± 0.46 kg, LB = 0.90 ± 0.29 kg, UB + LB = 1.38 ± 0.70 kg, compared to no changes after control. Serum follistatin increased in the LB = 0.24 ± 0.06 ng mL-1, UB = 0.27 ± 0.17 ng mL-1, UB + LB = 0.50 ± 0.18 ng mL-1, while serum myostatin decreased in the LB = - 0.11 ± 0.08 ng mL-1 and UB + LB = - 0.34 ± 0.23 ng mL-1, but not UB = 0.07 ± 0.16 ng mL-1. Further, change in concentration following training was larger between UB + LB and either LB or UB alone for both follistatin and myostatin. CONCLUSIONS:Both UB and LB increase muscle mass and alter the F: M ratio; however, the change in these endocrine markers is approximately twice as large if UB and LB is combined. The endocrine response to RT of myostatin and follistatin may depend on the volume of muscle mass activated during training

Neutron spectroscopic study of crystal field excitations in Tb2Ti2O7 and Tb2Sn2O7

We present time-of-flight inelastic neutron scattering measurements at low temperature on powder samples of the magnetic pyrochlore oxides Tb2Ti2O7 and Tb2Sn2O7. These two materials possess related, but different ground states, with Tb2Sn2O7 displaying "soft" spin ice order below Tn~0.87 K, while Tb2Ti2O7 enters a hybrid, glassy spin ice state below Tg~0.2 K. Our neutron measurements, performed at T=1.5 K and 30 K, probe the crystal field states associated with the J=6 states of Tb3+ within the appropriate Fd\bar{3}m pyrochlore environment. These crystal field states determine the size and anisotropy of the Tb3+ magnetic moment in each material's ground state, information that is an essential starting point for any description of the low-temperature phase behavior and spin dynamics in Tb2Ti2O7 and Tb2Sn2O7. While these two materials have much in common, the cubic stanate lattice is expanded compared to the cubic titanate lattice. As our measurements show, this translates into a factor of ~2 increase in the crystal field bandwidth of the 2J+1=13 states in Tb2Ti2O7 compared with Tb2Sn2O7. Our results are consistent with previous measurements on crystal field states in Tb2Sn2O7, wherein the ground state doublet corresponds primarily to m_J=|\pm 5> and the first excited state doublet to mJ=|\pm 4>. In contrast, our results on Tb2Ti2O7 differ markedly from earlier studies, showing that the ground state doublet corresponds to a significant mixture of mJ=|\pm 5>, |\mp 4>, and |\pm 2>, while the first excited state doublet corresponds to a mixture of mJ=|\pm 4>, |\mp 5>, and |\pm 1>. We discuss these results in the context of proposed mechanisms for the failure of Tb2Ti2O7 to develop conventional long-range order down to 50 mK.Comment: 12 pages, 6 figures. Version is the same as the published one, except for figure placement on page

A study of 4−4-cycle systems

A $4-$cycle system is a partition of the edges of the complete graph $K_n$ into $4-$cycles. Let ${ C}$ be a collection of cycles of length 4 whose edges partition the edges of $K_n$. A set of 4-cycles $T_1 \subset C$ is called a 4-cycle trade if there exists a set $T_2$ of edge-disjoint 4-cycles on the same vertices, such that $({C} \setminus T_1)\cup T_2$ also is a collection of cycles of length 4 whose edges partition the edges of $K_n$. We study $4-$cycle trades of volume two (double-diamonds) and three and show that the set of all 4-CS(9) is connected with respect of trading with trades of volume 2 (double-diamond) and 3. In addition, we present a full rank matrix whose null-space is containing trade-vectors

Polymorphism and synergism of angiotensin-converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) genes in coronary artery disease

Introduction: Among the genetic factors for coronary artery diseases, PAI-1 4G/5G and ACE I/D polymorphisms can be noted. This study was carried out to investigate the association of these two polymorphisms and their synergism in coronary artery disease (CAD) from a sample of the Iranian population. Materials and methods: Sixty-one patients with a history of CAD and 92 healthy controls participated in our study. After DNA extraction from leukocytes, PCR was performed to characterize PAI-1 4G/5G and ACE I/D polymorphisms, using an amplification refractory mutation system technique. Results: In the studied patients, PAI-1 polymorphisms were 24.6, 45.9, and 29.5 for 4G/4G, 4G/5G and 5G/5G, respectively; the values for controls were 20.7, 42.2 and 37.0. The distribution rates of genotypes I/I, I/D and D/D in patients accounted for 29.5, 45.9 and 24.6; in the control group these figures were estimated to be 40.2, 40.2 and 19.6. Conclusion: Single and multivariate analyses showed a significant difference for the conventional risk factors, including hypertension, diabetes, hyperlipidemia, smoking and family history, for CAD between patients and controls (p value 0.001). However, no significant correlation was demonstrated considering ACE and PAI-1 polymorphisms either in association with 4G/4G or D/D genotypes or a combination of them in the Iranian population in the current study. © 2015 The Author(s)