Does Group Contact Shape Styles of Pictorial Representation? A Case Study of Australian Rock Art.

Image-making is a nearly universal human behavior, yet the visual strategies and conventions to represent things in pictures vary greatly over time and space. In particular, pictorial styles can differ in their degree of figurativeness, varying from intersubjectively recognizable representations of things to very stylized and abstract forms. Are there any patterns to this variability, and what might its ecological causes be? Experimental studies have shown that demography and the structure of interaction of cultural groups can play a key role: the greater the degree of contact with other groups, the more recognizable and less abstract are the representations. Here we test this hypothesis on a real-world dataset for the first time. We constructed a balanced database of Indigenous Australian rock art motifs from both isolated and contact Aboriginal groups (those often in contact with other groups). We then ran a survey asking participants to judge the recognizability of the motifs and to provide interpretations. Results show that motifs from contact Aboriginal groups were more likely to be judged as inter-subjectively recognizable and also elicited more convergent descriptions than motifs from isolated groups. This is consistent with the idea that intergroup contact is likely to be an important factor in the cultural evolution of pictorial representation. We discuss the implications of these findings for the archaeology and anthropology of art, and the parallels with language evolution.

Mooney-Rivlin biomechanical modeling of lung with Inhomogeneous material.

In this study, the Mooney-Rivlin material with hyperelastic strain energy was proposed for biomechanical modeling of the lung. We modeled the lung as an inhomogeneous Mooney-Rivlin material with uncoupled deviatoric and volumetric behavior. The proposed method was evaluated on the lungs of eight lung cancer patients. For each patient, the lung was segmented from the 4D-CT images and tetrahedral volume mesh of the lung in phase 50% was created by using the adaptive mesh generation toolkit. The demons deformable registration algorithm was used to extract the displacement vector fields (DVFs). The Jacobian of the deformation gradient was calculated from DVFs, and the lung strain energy function was optimized to improve the tumor center of mass (TCM) motion simulation accuracy between respiratory phase 50% and 0%. The average TCM motion simulation error for the proposed strategy is 1.95 mm for eight patients. We observed 13% improvement in the TCM position prediction compared with the homogeneous Mooney-Rivlin modeling.

Evaluation of different stimulation and measurement patterns based on internal electrode: application in cardiac impedance tomography.

The conductivity distribution around the thorax is altered during the cardiac cycle due to the blood perfusion, heart contraction and lung inflation. Previous studies showed that these bio-impedance changes are appropriate for non-invasive cardiac function imaging using Electrical Impedance Tomography (EIT) techniques. However, the spatial resolution is presently low. One of the main obstacles in cardiac imaging at the heart location is the large impedance variation of the lungs by respiration and muscles on the dorsal and posterior side of the body. In critical care units there is a potential to insert an internal electrode inside the esophagus directly behind the heart in the same plane of the external electrodes. The aim of the present study is to evaluate different current stimulation and measurement patterns with both external and internal electrodes. Analysis is performed with planar arrangement of 16 electrodes for a simulated 3D cylindrical tank and pig thorax model. In our study we evaluated current injection patterns consisting of adjacent, diagonal, trigonometric, and radial to the internal electrode. The performance of these arrangements was assessed using quantitative methods based on distinguishability, sensitivity and GREIT (Graz consensus Reconstruction algorithm for Electrical Impedance Tomography). Our evaluation shows that an internal electrode configuration based on the trigonometric injection patterns has better performance and improves pixel intensity of the small conductivity changes related to heart near 1.7 times in reconstructed images and also shows more stability with different levels of added noise. For the internal electrode, when we combined radial or adjacent injection with trigonometric injection pattern, we found an improvement in amplitude response. However, the combination of diagonal with trigonometric injection pattern deteriorated the shape deformation (correlation coefficient r=0.344) more than combination of radial and trigonometric injection (correlation coefficient r=0.836) for the perturbations in the area close to the center of the cylinder. We also find that trigonometric stimulation pattern performance is degraded in a realistic thorax model with anatomical asymmetry. For that reason we recommend using internal electrodes only for voltage measurements and as a reference electrode during trigonometric stimulation patterns in practical measurements.

Modelling of an oesophageal electrode for cardiac function tomography.

There is a need in critical care units for continuous cardiopulmonary monitoring techniques. ECG gated electrical impedance tomography is able to localize the impedance variations occurring during the cardiac cycle. This method is a safe, inexpensive and potentially fast technique for cardiac output imaging but the spatial resolution is presently low, particularly for central locations such as the heart. Many parameters including noise deteriorate the reconstruction result. One of the main obstacles in cardiac imaging at the heart location is the high impedance of lungs and muscles on the dorsal and posterior side of body. In this study we are investigating improvements of the measurement and initial conductivity estimation of the internal electrode by modelling an internal electrode inside the esophagus. We consider 16 electrodes connected around a cylindrical mesh. With the random noise level set near 0.05% of the signal we evaluated the Graz consensus reconstruction algorithm for electrical impedance tomography. The modelling and simulation results showed that the quality of the target in reconstructed images was improved by up to 5 times for amplitude response, position error, resolution, shape deformation and ringing effects with perturbations located in cardiac related positions when using an internal electrode.

Mental illness and criminal violence.

This article examines the relationship between criminal violence and mental illness. Our data suggest that mentally ill persons tend to have an increased risk for committing violent offenses, and that the violent offending by these individuals tends to be recidivistic. Our findings suggest that parents who have both committed violent offenses and experienced a psychiatric hospitalization increase the risk of violent offending among their offspring. We propose the hypothesis that mentally ill parents transmit a biological characteristic which may genetically predispose their child towards criminal violence. Prenatal disturbances during critical periods of fetal development may provide clues regarding the etiology of criminal violence.

Analysis of endoproteinase Arg C action on adrenocorticotrophic hormone by capillary electrophoresis and reversed-phase high-performance liquid chromatography.

The specificity and rate of cleavage of adrenocorticotrophic hormone (ACTH) peptide bonds by endoproteinase Arg C were analyzed using capillary electrophoresis (CE) and reversed-phase (C18) high-performance liquid chromatography (HPLC). Acidic cleavage products were readily resolved by CE in uncoated capillaries using low ionic strength electrolytes. However, products predicted to have a net positive charge greater than 2 or more than 4 positively charged groups per peptide did not migrate out from the capillary at low ionic strength. Addition of salts and zwitterions to the electrolyte decreased capillary-peptide interactions such that all of the ACTH peptides examined were eluted with high efficiency separation by CE. Commercially obtained endoproteinase Arg C preparations exhibited peptidase activity at Lys-15-Lys16 and at Lys16-Arg17 in addition to the expected cleavage at Arg-X bonds. ACTH peptide bond cleavage rates for Arg8-Trp9, Arg17-Arg-18, Lys15-Lys16, and Lys16-Arg17 were 1.46, 0.096, 0.57, and 0.029 mumol min-1 mg-1 respectively. CE separations generally exhibited better resolution and were accomplished in shorter times than C18 HPLC separations. These properties make CE a particularly appropriate method for kinetic analysis of proteolytic enzyme action on peptide substrates.

Antibodies in calves on feed supplemented with chlortetracycline after vaccination with Brucella abortus strain 19.

Twenty dairy heifers each consumed 350 mg of chlortetracycline/day in their feed. Four tests were performed on serum specimens from these and 20 control calves after vaccination with Brucella abortus strain 19. The numbers of positive test results on the card test and mean titers on the tube and rivanol agglutination and complement-fixation tests were compared in the 2 groups. Using the rivanol and complement-fixation tests, there were differences in the mean titers at weeks 5 and 6 after vaccination, but by week 10, differences were not found. The results suggest that addition of low concentration of chlortetracycline in feeds have minimal effects on postvaccinal serologic reactions determined after strain-19 inoculation.

Blood pressure, electrocardiogram and echocardiogram measurements in the growing pony foal.

Twelve newborn pony foals underwent cardiovascular examinations (auscultation, arterial blood pressure measurements, electrocardiograms and M-mode echocardiograms) on their first day of life and then on Days 7, 14, 21, 30, 60 and 90. An age dependent, statistically significant, rapid increase of the arterial blood pressure in the first month was documented together with a slower decrease of the resting heart rate after two and three months of life. Innocent soft systolic murmurs were audible over the left heart base in a large number of the foals. The electrocardiograms showed age dependent increases of the PR-, QRS- and QT- intervals and a trend of the mean electrical axis in the frontal plane to rotate towards the left side. The ventricular dimensions, measured by M-mode echocardiography, increased with the growth of the pony foals. Linear regression equations were calculated for the right and left ventricular internal dimensions in relation to body weight (bwt). The other echocardiographic parameter had low correlations with bwt.