The Chiral Potts Spin Glass in d=2 and 3 Dimensions

The chiral spin-glass Potts system with q=3 states is studied in d=2 and 3 spatial dimensions by renormalization-group theory and the global phase diagrams are calculated in temperature, chirality concentration p, and chirality-breaking concentration c, with determination of phase chaos and phase-boundary chaos. In d=3, the system has ferromagnetic, left-chiral, right-chiral, chiral spin-glass, and disordered phases. The phase boundaries to the ferromagnetic, left- and right-chiral phases show, differently, an unusual, fibrous patchwork (microreentrances) of all four (ferromagnetic, left-chiral, right-chiral, chiral spin-glass) ordered ordered phases, especially in the multicritical region. The chaotic behavior of the interactions, under scale change, are determined in the chiral spin-glass phase and on the boundary between the chiral spin-glass and disordered phases, showing Lyapunov exponents in magnitudes reversed from the usual ferromagnetic-antiferromagnetic spin-glass systems. At low temperatures, the boundaries of the left- and right-chiral phases become thresholded in p and c. In the d=2, the chiral spin-glass system does not have a spin-glass phase, consistently with the lower-critical dimension of ferromagnetic-antiferromagnetic spin glasses. The left- and right-chirally ordered phases show reentrance in chirality concentration p.Comment: 9 pages, 7 figures, 19 phase diagrams. Final published versio

Successively Thresholded Domain Boundary Roughening Driven by Pinning Centers and Missing Bonds: Hard-Spin Mean-Field Theory Applied to d=3 Ising Magnets

Hard-spin mean-field theory has recently been applied to Ising magnets, correctly yielding the absence and presence of an interface roughening transition respectively in $d=2$ and $d=3$ dimensions and producing the ordering-roughening phase diagram for isotropic and anisotropic systems. The approach has now been extended to the effects of quenched random pinning centers and missing bonds on the interface of isotropic and anisotropic Ising models in $d=3$. We find that these frozen impurities cause domain boundary roughening that exhibits consecutive thresholding transitions as a function interaction of anisotropy. For both missing-bond and pinning-center impurities, for moderately large values the anisotropy, the systems saturate to the "solid-on-solid" limit, exhibiting a single universal curve for the domain boundary width as a function of impurity concentration.Comment: Published version, 4 pages, 5 figure

Phase Transitions between Different Spin-Glass Phases and between Different Chaoses in Quenched Random Chiral Systems

The left-right chiral and ferromagnetic-antiferromagnetic double spin-glass clock model, with the crucially even number of states q=4 and in three dimensions d=3, has been studied by renormalization-group theory. We find, for the first time to our knowledge, four different spin-glass phases, including conventional, chiral, and quadrupolar spin-glass phases, and phase transitions between spin-glass phases. The chaoses, in the different spin-glass phases and in the phase transitions of the spin-glass phases with the other spin-glass phases, with the non-spin-glass ordered phases, and with the disordered phase, are determined and quantified by Lyapunov exponents. It is seen that the chiral spin-glass phase is the most chaotic spin-glass phase. The calculated phase diagram is also otherwise very rich, including regular and temperature-inverted devil's staircases and reentrances.Comment: 7 pages, 4 figures, 12 chaotic trajectories. Final published version. arXiv admin note: text overlap with arXiv:1612.0333

Discovery of Escherichia coli methionyl-tRNA synthetase mutants for efficient labeling of proteins with azidonorleucine in vivo

Incorporation of noncanonical amino acids into cellular proteins often requires engineering new aminoacyl-tRNA synthetase activity into the cell. A screening strategy that relies on cell-surface display of reactive amino acid side-chains was used to identify a diverse set of methionyl-tRNA synthetase (MetRS) mutants that allow efficient incorporation of the methionine (Met) analog azidonorleucine (Anl). We demonstrate that the extent of cell-surface labeling in vivo is a good indicator of the rate of Anl activation by the MetRS variant harbored by the cell. By screening at low Anl concentrations in Met-supplemented media, MetRS variants with improved activities toward Anl and better discrimination against Met were identified

A Cost-Effective and Simplified Integration of Simulations and Hands-on Experiments in the Teaching of Electronic Instrumentation and Measurement Laboratory Course

To develop students into effective engineers upon graduation, it is important to bridge the gap between theory and practice. This is achieved through hands-on laboratory experiments, which form an important part of engineering education especially electronic circuits-related courses within the undergraduate level of education. Hence, it is important to develop well-outlined laboratory experiments that reflect the theoretical part of a course. Equally important is comparing simulation and measurement data, to better appreciate the theory. This work presents integrated simulation and hands-on experiments in teaching electronic instrumentation and measurement laboratory course, using low-cost off-the-shelf components. A no-cost circuit simulator software (LTspice) and low-cost breadboard with readily available off-the-shelf circuit components can be used both at home (self-paced) and in the laboratory to motivate students and align results for an improved learning approach. The advantage of this integrated laboratory is that no specialized or expensive teaching kit is required, which improves accessibility and course delivery. In addition, based on the feedback received, students are satisfied with this simplified and low-cost integrated laboratory

Determination of normal splenic volume in relation to age, gender and body habitus: a stereological study on computed tomography

Background: The aim of this study is to assess and document the dimensions of the normal spleen measured on computed tomography (CT) images with the normal splenic volume measured by Cavalieri principle on CT images and thereby serve as a baseline for comparison in cases of splenomegaly using abdominal CT. To investigate the relationship between these changes and body mass index, gender, abdominal diameters.Materials and methods: We retrospectively reviewed abdominal CT examinations of 212 adults between the ages of 20 and 88 years. There were seven groups of patients. The spleen volume (SV) measurements using abdominal CT images of each patient on the Image Information Systems were performed with Cavalieri principle.Results: The mean SV and splenic length (SL), width (SW), and thickness (ST) for the total study population of 212 patients was 198 ± 88 cm3, 9.96 ± 2.1 cm, 8.87 ±± 1.6 cm and 4.58 ± 0.8 cm, respectively. There was a strong correlation between SV and ST (r = 0.752, p < 0.001), SL (r = 0.735, p < 0.001), SW (r = 0.681,p < 0.001) mean values of total study population. Comparison between mean splenic dimension parameters for males and females showed a statistically significant difference (p = 0.032 for SV, p = 0.04 for ST) but no statistically significant difference with SL and SW. Also there was a positive correlation between SV and body height, sagittal abdominal diameter and transvers abdominal diameter in mean of total groups and female groups, there was no correlation in males.Conclusions: The normal reference ranges for SV and size given in this study canserve as a standard to judge whether splenomegaly is present in patients

Tracking Flanker Task Dynamics: Evidence for Continuous Attentional Selectivity

A central research goal in the cognitive sciences has been to understand the processes that underlie selective attention, or the ability to focus on goal-relevant information. Two opposing theories have been proposed in an effort to explain how selective attention emerges: one suggests that attention improves continuously over time, whereas the other proposes that attention improves at a discrete time point. While outcome-based data (e.g., reaction time) have successfully provided evidence for both accounts, there has been no empirical evidence to differentiate them. In this study, we used mouse-tracking in a flanker task that provided time sensitive measures associated with selective attention. Specifically, we recorded the path of real-time movement trajectories to assess characteristics of continuous and discrete shifts in selective attention. Our results strongly suggested that selective attention increased gradually over time, as opposed to at a discrete point, thus providing support for a continuous account of selective attention

Volumetric evaluation of fat in the renal sinus in normal subjects using stereological method on computed tomography images and its relationship with body composition

Background: The aim of the study was: to describe a simple, accurate and practical technique for estimating the volume of adipose tissue within the renal sinus (RS) using stereological method on computed tomography (CT) images; to establish a population database for volume of fat within the RS from 21 to 80 years of age; to investigate the effect of age, gender, body mass index (BMI) and abdominal diameters on RS fat volume in normal subjects.Materials and methods: We retrospectively reviewed abdominal CT examinations of 240 patients without renal pathology between the ages of 21 and 80 years. There were 6 groups of patients, with 40 patients for each decade.Results: RS fat volumes in the left and right kidney were 5.70 ± 2.87 cm3 and 4.15 ± 2.39 cm3, respectively, in males and 3.51 ± 2.67 cm3 and 2.49 ± 2.16 cm3, respectively, in females. RS fat volume and age were positively correlated for both kidneys (left: r = 0.46; right: r = 0.44; p < 0.001, both), though it appeared to decline after age 70.Conclusions: Quantitative data may allow clinicians to better estimate the age-related RS fat volume changes and help them in decision making