22 research outputs found

    Exploring Mondrian Compositions in Three-Dimensional Space

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    The dogmatic nature of Piet Mondrian’s neoplasticism manifesto initiated a discourse about translating aesthetic ideals from paintings to 3D structures. Mondrian rarely ventured into architectural design, and his unique interior design of “Salon de Madame B … à Dresden” was not executed. The authors discuss physical constraints and perceptual factors that conflict with neoplastic ideals. Using physical and virtual models of the salon, the authors demonstrate challenges with perspective projections and show how such distortions could be minimized in a cylinder. The paradoxical percept elicited by a “reverspective” Mondrian-like space further highlights the essential role of perceptual processes in reaching neoplastic standards of beauty. </jats:p

    Aortic stiffness is associated with cardiac function and cerebral small vessel disease in patients with type 1 diabetes mellitus: assessment by magnetic resonance imaging

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    To evaluate, with the use of magnetic resonance imaging (MRI), whether aortic pulse wave velocity (PWV) is associated with cardiac left ventricular (LV) function and mass as well as with cerebral small vessel disease in patients with type 1 diabetes mellitus (DM). We included 86 consecutive type 1 DM patients (49 male, mean age 46.9 +/- 11.7 years) in a prospective, cross-sectional study. Exclusion criteria included aortic/heart disease and general MRI contra-indications. MRI of the aorta, heart and brain was performed for assessment of aortic PWV, as a marker of aortic stiffness, systolic LV function and mass, as well as for the presence of cerebral white matter hyperintensities (WMHs), microbleeds and lacunar infarcts. Multivariate linear or logistic regression was performed to analyse the association between aortic PWV and outcome parameters, with covariates defined as age, gender, mean arterial pressure, heart rate, BMI, smoking, DM duration and hypertension. Mean aortic PWV was 7.1 +/- 2.5 m/s. Aortic PWV was independently associated with LV ejection fraction ( = -0.406, P = 0.006), LV stroke volume ( = -0.407, P = 0.001), LV cardiac output ( = -0.458, P = 0.001), and with cerebral WMHs (P < 0.05). There were no independent associations between aortic stiffness and LV mass, cerebral microbleeds or lacunar infarcts. Aortic stiffness is independently associated with systolic LV function and cerebral WMHs in patients with type 1 DM.Neuro Imaging Researc

    Bramwell-Hill modeling for local aortic pulse wave velocity estimation: a validation study with velocity-encoded cardiovascular magnetic resonance and invasive pressure assessment

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    <p>Abstract</p> <p>Background</p> <p>The Bramwell-Hill model describes the relation between vascular wall stiffness expressed in aortic distensibility and the pulse wave velocity (PWV), which is the propagation speed of the systolic pressure wave through the aorta. The main objective of this study was to test the validity of this model locally in the aorta by using PWV-assessments based on in-plane velocity-encoded cardiovascular magnetic resonance (CMR), with invasive pressure measurements serving as the gold standard.</p> <p>Methods</p> <p>Seventeen patients (14 male, 3 female, mean age ± standard deviation = 57 ± 9 years) awaiting cardiac catheterization were prospectively included. During catheterization, intra-arterial pressure measurements were obtained in the aorta at multiple locations 5.8 cm apart. PWV was determined regionally over the aortic arch and locally in the proximal descending aorta. Subsequently, patients underwent a CMR examination to measure aortic PWV and aortic distention. Distensibility was determined locally from the aortic distension at the proximal descending aorta and the pulse pressure measured invasively during catheterization and non-invasively from brachial cuff-assessment. PWV was determined regionally in the aortic arch using through-plane and in-plane velocity-encoded CMR, and locally at the proximal descending aorta using in-plane velocity-encoded CMR. Validity of the Bramwell-Hill model was tested by evaluating associations between distensibility and PWV. Also, theoretical PWV was calculated from distensibility measurements and compared with pressure-assessed PWV.</p> <p>Results</p> <p>In-plane velocity-encoded CMR provides stronger correlation (p = 0.02) between CMR and pressure-assessed PWV than through-plane velocity-encoded CMR (r = 0.69 versus r = 0.26), with a non-significant mean error of 0.2 ± 1.6 m/s for in-plane versus a significant (p = 0.006) error of 1.3 ± 1.7 m/s for through-plane velocity-encoded CMR. The Bramwell-Hill model shows a significantly (p = 0.01) stronger association between distensibility and PWV for local assessment (r = 0.8) than for regional assessment (r = 0.7), both for CMR and for pressure-assessed PWV. Theoretical PWV is strongly correlated (r = 0.8) with pressure-assessed PWV, with a statistically significant (p = 0.04) mean underestimation of 0.6 ± 1.1 m/s. This theoretical PWV-estimation is more accurate when invasively-assessed pulse pressure is used instead of brachial cuff-assessment (p = 0.03).</p> <p>Conclusions</p> <p>CMR with in-plane velocity-encoding is the optimal approach for studying Bramwell-Hill associations between local PWV and aortic distensibility. This approach enables non-invasive estimation of local pulse pressure and distensibility.</p

    Cross-ethnic assessment of body weight and height on the basis of faces

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    Previous research has revealed a strong relationship between mere visual facial cues and body weight. They can be exploited to validly judge the weight of the human body. We tested to what extent observers are able to judge body weight and height on the basis of same-ethnicity and different-ethnicity faces. Caucasian and Asian observers saw Caucasian and Asian faces and estimated the person’s weight and height – merely on the basis of greyscale photographs of the face. These height and weight estimates were influenced by ethnocentric specifics of familiar face proportion and face–body relationship. Ownethnicity weight estimations showed higher accuracy than foreign-ethnicity estimations. Observers ignored the changed base-rate for weight of other-culture faces in a culture-egocentric fashion. Height judgments, in contrast, reflect a higher degree of sophistication. A bias toward the own, familiar body proportion was visible here, especially for Japanese observers—however, the height judgments showed that observers were able to incorporate the other-ethnicity height proportion to some exten

    Molecular sex determination of 20 bird species protected in the Republic of Serbia

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    Considering that more than 50% of bird species are monomorphic, the identification of gender based on phenotypic characteristics is extremely difficult. The aim of this study is sex determination in species inhabiting the Republic of Serbia, all under the state protection and declared by IUCN as endangered. DNA was isolated from feathers. Sex determination was based on sex-specific CHD gene amplified by 2550F/2718R primer set. Sexing gave good results in all 91 samples from 20 species including 6 species where molecular sexing has not previously been successful. [Projekat Ministarstva nauke Republike Srbije, br. 46002
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