1,829 research outputs found

    Appearance of symmetry, beauty, and health in human faces

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    Symmetry is an important concept in biology, being related to mate selection strategies, health, and survival of species. In human faces, the relevance of left-right symmetry to attractiveness and health is not well understood. We compared the appearance of facial attractiveness, health, and symmetry in three separate experiments. Participants inspected front views of faces on the computer screen and judged them on a 5-point scale according to their attractiveness in Experiment 1, health in Experiment 2, and symmetry in Experiment 3. We found that symmetry and attractiveness were not strongly related in faces of women or men while health and symmetry were related. There was a significant difference between attractiveness and symmetry judgments but not between health and symmetry judgments. Moreover, there was a significant difference between attractiveness and health. Facial symmetry may be critical for the appearance of health but it does not seem to be critical for the appearance of attractiveness, not surprisingly perhaps because human faces together with the human brain have been shaped by adaptive evolution to be naturally asymmetrical

    Operating Islamic Jurisprudence in Non-Muslim Jurisdictions: Traditional Islamic Precepts and Contemporary Controversies in the United States

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    With the recent public furor in the United States regarding “Shari‘a,” studies into the content of Islamic jurisprudence concerning Muslims living under non-Muslim jurisdiction are more pertinent than ever in the U.S. context. As “anti-Shari‘a” rhetoric has increased in fervency, informed input into the debates could go some way in correcting the peddled misconceptions. The paper begins by assessing how Muslim scholars viewed a Muslim’s travel to and residence in non-Muslim lands, and the obligation to abide by the laws of the land. It will focus on the jihad (siyar) section in Islamic jurisprudence and the section on judiciary (qaḍā’/adab al-qāḍī), and overlapping discussions of relevance pertaining to criminal law and financial law. The section on jihad assesses the issue of jurisdiction in terms of whether Islamic law can be applied to crimes committed in non-Muslim lands. A study of the section on judiciary will show how Islamic jurisprudence provides a means for Muslims to adjudicate among themselves in a non-Muslim polity. While much of the focus is on the Ḥanafī School of jurisprudence, comparisons will be made to other schools where possible, discerning areas of convergence and points of departure. Once this has been discovered, the actual intersection of Shari‘a and the American legal system will identify the fallacy of anti-Shari‘a propaganda. In doing so, I argue that a common sense approach is required that recognizes the accommodating principles in both legal traditions

    Glutathione-S-Transferase and Thiol Stress in patients with acute renal failure

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    Introduction: Tubular damage is common finding in acute renal failure (ARF). Various etiologies have been put forth to explain the tubular damage in ARF, one important mechanism among them is oxidative damage to renal tubules. Several biomolecules including low-molecular weight peptides and enzymes in urine have been proposed as early markers of renal failure. Current study has been undertaken to study the thiol stress and glutathione-S-transferase (GST) levels in ARF patients. Method: 58 ARF patients and 55 healthy controls were selected based on inclusion and exclusion criteria. Serum thiols, GST, malanoldehyde (MDA) and urine thiols were determined by spectrophotometer based methods. Results: Serum thiols and urine thiols were significantly decreased (p<0.0001), and serum GST and MDA levels were significantly increased (p<0.0001) in ARF patients compared to healthy controls. Serum GST and MDA correlated positively in ARF cases (r2 = 0.6938, p<0.0001). Conclusion: There is significant thiol stress and increased lipid peroxidation in ARF patients which leads to tubular cell membrane damage and release of GST into blood stream and into urine. This may be possible mechanism for the increased presence of GST in urine (enzymuria) found in other studie

    Phase field theory modeling of CH4/CO2 gas hydrates in gravity fields

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    Natural gas hydrates in reservoirs are thermodynamically unstable due to the interactions with surrounding fluids (aqueous, gas) and mineral surfaces. Depending on the local flow hydrate will dissociate as well as reform. If the dissociation rate is faster than the capacity of the surrounding fluids to dissolve the released gas, the gas will form bubbles. Depending on the rate of released gas and possible fracture patterns this may lead to venting of gas. The proper implementation of hydrodynamics will provide a deeper insight of the hydrate kinetics involved during dissociation and formation processes which involve hydrate former phase as smaller or larger bubbles or even continuous gas phase. In this work the phase field theory coupled with hydrodynamics model is implemented with variable density using the relative composition, phase field parameter and flow, which is an extension of our previous work which considers a constant density.publishedVersio

    String tension in gonihedric 3D Ising models

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    For the 3D gonihedric Ising models defined by Savvidy and Wegner the bare string tension is zero and the energy of a spin interface depends only on the number of bends and self-intersections, in antithesis to the standard nearest-neighbour 3D Ising action. When the parameter kappa weighting the self-intersections is small the model has a first order transition and when it is larger the transition is continuous. In this paper we investigate the scaling of the renormalized string tension, which is entirely generated by fluctuations, using Monte Carlo simulations This allows us to obtain an estimate for the critical exponents alpha and nu using both finite-size-scaling and data collapse for the scaling function.Comment: Latex + postscript figures. 8 pages text plus 7 figures, spurious extra figure now removed

    The Phase Diagram of Crystalline Surfaces

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    We report the status of a high-statistics Monte Carlo simulation of non-self-avoiding crystalline surfaces with extrinsic curvature on lattices of size up to 1282128^2 nodes. We impose free boundary conditions. The free energy is a gaussian spring tethering potential together with a normal-normal bending energy. Particular emphasis is given to the behavior of the model in the cold phase where we measure the decay of the normal-normal correlation function.Comment: 9 pages latex (epsf), 4 EPS figures, uuencoded and compressed. Contribution to Lattice '9

    Scaling laws for the 2d 8-state Potts model with Fixed Boundary Conditions

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    We study the effects of frozen boundaries in a Monte Carlo simulation near a first order phase transition. Recent theoretical analysis of the dynamics of first order phase transitions has enabled to state the scaling laws governing the critical regime of the transition. We check these new scaling laws performing a Monte Carlo simulation of the 2d, 8-state spin Potts model. In particular, our results support a pseudo-critical beta finite-size scaling of the form beta(infinity) + a/L + b/L^2, instead of beta(infinity) + c/L^d + d/L^{2d}. Moreover, our value for the latent heat is 0.294(11), which does not coincide with the latent heat analytically derived for the same model if periodic boundary conditions are assumed, which is 0.486358...Comment: 10 pages, 3 postscript figure

    Cold atoms in non-Abelian gauge potentials: From the Hofstadter "moth" to lattice gauge theory

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    We demonstrate how to create artificial external non-Abelian gauge potentials acting on cold atoms in optical lattices. The method employs nn internal states of atoms and laser assisted state sensitive tunneling. Thus, dynamics are communicated by unitary n×nn\times n-matrices. By experimental control of the tunneling parameters, the system can be made truly non-Abelian. We show that single particle dynamics in the case of intense U(2) vector potentials lead to a generalized Hofstadter butterfly spectrum which shows a complex ``moth''-like structure. We discuss the possibility to employ non-Abelian interferometry (Aharonov-Bohm effect) and address methods to realize matter dynamics in specific classes of lattice gauge fields.Comment: 5 pages, 3 figure

    On the Logarithmic Triviality of Scalar Quantum Electrodynamics

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    Using finite size scaling and histogram methods we obtain numerical results from lattice simulations indicating the logarithmic triviality of scalar quantum electrodynamics, even when the bare gauge coupling is chosen large. Simulations of the non-compact formulation of the lattice abelian Higgs model with fixed length scalar fields on L4L^{4} lattices with LL ranging from 66 through 2020 indicate a line of second order critical points. Fluctuation-induced first order transitions are ruled out. Runs of over ten million sweeps for each LL produce specific heat peaks which grow logarithmically with LL and whose critical couplings shift with LL picking out a correlation length exponent of 0.50(5)0.50(5) consistent with mean field theory. This behavior is qualitatively similar to that found in pure λϕ4\lambda\phi^{4}.Comment: 9 page
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