Computational analyses of dynamics of architectural space

Although space is the central element of architecture, questions of space are hardly addressed in computational research in architecture. On the other hand, current mainstream practice in computational design research in architecture tends to focus on efficiency of architectural procedures, entailing optimisation of form, structure, performance, data management or workflow, etc. Such focus utilises computation to handle quantitative data of tangible properties in architecture. However, architectural space is filled with abstract qualitative properties, one of which is its dynamics. Dynamic properties of architectural space have been discussed in diverse disciplines from diverse perspectives since the nineteenth century, but it is only in the past decades that some of the theories are revisited due to discoveries in neuroscience. Such reappraisal of past theories by new technologies anticipates further rediscovery of qualitative properties of architectural space, such as spatial dynamics, that have been investigated largely through speculative descriptive methods using phenomenological approaches. Hence, the research explores the idea of architectural space as dynamic field structures by reexamining theories since the nineteenth century in multiple disciplines, and develops a system of computational inquiries to investigate dynamics of architectural space. The computational procedures produce visual spatial data that are analysed and calibrated in comparison to the past studies of architectural space based on descriptive methods. The correlations observed between the two approaches substantiate potentials of the computational approach as ways to study abstract properties of architectural space further.Peer reviewe

Mercury emissions in volcanic gases from Mt. Etna, Italy.

Mercury is a global pollutant that can be found in different forms and different ecosystems. Special attention has recently been devoted to mercury due to its high chemical reactivity, its global spreading, its biogeochemical cycling, its transformations in the environment, its ability for biomagnification and its high toxicity. Beside anthropogenic sources, mercury can also be of natural origin. Among natural Hg sources, volcanoes can be important. Volcanic gas emissions may be rich in elemental gaseous mercury (Hg0), reactive gaseous mercury (HgII) and other mercury forms. Mt. Etna (Sicily, Italy) is one of the most active volcanoes in the world and one of the largest contributors of magmatic volatiles to the environment; consequently, we tried to estimate its contribution to regional and global Hg budgets and tested the eligibility of Hg as a tool for volcano monitoring. Mercury concentrations have been measured on Mt. Etna during several campaigns carried out between 2004 and 2007 in fumaroles, mofettes and diffuse degassing areas, as well as in the air inside and across the volcanic plume. In addition, Hg fluxes have been measured by flux chamber technique. Mercury concentrations measured in air below the volcanic plume in November 2004 ranged between 4 and 30 ng m-3 at low altitude, and between 65 and 132 ng m-3 close to the summit craters. A profile of Hg in the air below the volcanic plume carried out on helicopter on November 2006 showed Hg concentrations up to 60 ng m-3. Hg contents in fumarole gases reached 64,200 ng m-3, and soil gas Hg showed temporal variations that reached the highest values (up to 240 ng m-3) in fall 2005. The highest Hg fluxes were measured in bubbling gas from mud volcanoes at the SW foot of Etna, reaching 1300 ng m-2 h-1. Mercury contents were found highly correlated both with water/mud temperature at mud volcanoes and with concurrent soil CO2 effluxes. In the latter case, hydrothermal gases showed higher values and a higher correlation than “cold”gases. Our results, therefore, look promising for the use of mercury in geochemical monitoring of volcanic activity

Further systematic computations on the summatory function of the Möbius function

In the past, the Mertens function M(x), i.e. the sum of the Moebius function ?(n) for 1 <= n <= x, has been computed for x <= 1013. We describe the results obtained by extending this range to x <= 1014, and discuss the prospects of such computations for even larger ranges

Statically motivated formfinding based on extended graphical statics

Abstract. In the 19 th century it was common to use graphical methods for study the relationship between form and force. The central element of all drawing methods for representing the inner flow of forces was the investigation of the dependence of equilibrium and force polygons, as well as their representation in two geometrically dependent diagrams with different units. This research is part of an on going project to extend the methods of &apos;graphical statics&apos; of Carl Culmann (1866) to the third dimension in order to overcome some of the 2D-limitations of this approach. It is focused on the construction of resulting force within 3D and the utilization within discrete space frames (tetrahedrons) in equilibrium. The objective of the EGS is to focus on constructing in contrast to calculating. That means that the logic of the inner force flow leads to a process-oriented and visible approach of design, which gets computationally accessible. With the use of digital tools and increasing importance of performative methods of form-finding a renewed interest in these vector-based geometric methods of construction of force flow has occurred. This maybe will give the possibility to get an alternative to the common form finding methods by relaxation processes and analysis by FEM

The prolate-to-oblate shape transition of phospholipid vesicles in response to frequency variation of an AC electric field can be explained by the dielectric anisotropy of a phospholipid bilayer

The external electric field deforms flaccid phospholipid vesicles into spheroidal bodies, with the rotational axis aligned with its direction. Deformation is frequency dependent: in the low frequency range (~ 1 kHz), the deformation is typically prolate, while increasing the frequency to the 10 kHz range changes the deformation to oblate. We attempt to explain this behaviour with a theoretical model, based on the minimization of the total free energy of the vesicle. The energy terms taken into account include the membrane bending energy and the energy of the electric field. The latter is calculated from the electric field via the Maxwell stress tensor, where the membrane is modelled as anisotropic lossy dielectric. Vesicle deformation in response to varying frequency is calculated numerically. Using a series expansion, we also derive a simplified expression for the deformation, which retains the frequency dependence of the exact expression and may provide a better substitute for the series expansion used by Winterhalter and Helfrich, which was found to be valid only in the limit of low frequencies. The model with the anisotropic membrane permittivity imposes two constraints on the values of material constants: tangential component of dielectric permittivity tensor of the phospholipid membrane must exceed its radial component by approximately a factor of 3; and the membrane conductivity has to be relatively high, approximately one tenth of the conductivity of the external aqueous medium.Comment: 17 pages, 6 figures; accepted for publication in J. Phys.: Condens. Matte

Murine Surf4 is essential for early embryonic development

Newly synthesized proteins co-translationally inserted into the endoplasmic reticulum (ER) lumen may be recruited into anterograde transport vesicles by their association with specific cargo receptors. We recently identified a role for the cargo receptor SURF4 in facilitating the secretion of PCSK9 in cultured cells. To examine the function of SURF4 in vivo, we used CRISPR/Cas9-mediated gene editing to generate mice with germline loss-of-function mutations in Surf4. Heterozygous Surf4+/- mice exhibit grossly normal appearance, behavior, body weight, fecundity, and organ development, with no significant alterations in circulating plasma levels of PCSK9, apolipoprotein B, or total cholesterol, and a detectable accumulation of intrahepatic apoliprotein B. Homozygous Surf4-/- mice exhibit embryonic lethality, with complete loss of all Surf4-/- offspring between embryonic days 3.5 and 9.5. In contrast to the milder murine phenotypes associated with deficiency of known SURF4 cargoes, the embryonic lethality of Surf4-/- mice implies the existence of additional SURF4 cargoes or functions that are essential for murine early embryonic development

IgE autoantibodies in serum and skin of non-bullous and bullous pemphigoid patients

Background Non-bullous pemphigoid (NBP) is a pemphigoid variant which frequently resembles other pruritic skin diseases. In contrast with bullous pemphigoid (BP), blisters are absent. In BP, previous studies showed that IgE autoantibodies may be involved in its pathogenesis. IgE-activated mast cells, basophils and eosinophils may participate in BP by inducing pruritus and possibly blister formation, although the differential role of IgE in NBP compared with BP has not yet been described. Objective To assess IgE in serum and skin of NBP and BP patients. Methods We examined total IgE and pemphigoid-specific IgE in the serum of 68 NBP and 50 BP patients by enzyme-linked immunosorbent assay (ELISA). Sera of 25 pemphigus patients and 25 elderly patients with pruritus were included as controls. Skin biopsies of 14 NBP and 14 BP patients with the highest IgE titres to NC16A were stained for IgE by immunofluorescence techniques. Results Total IgE was elevated in 63% of NBP and 60% of BP patients, and in 20% of pemphigus controls, as well as 60% of elderly controls. IgE ELISAs were more frequently positive in BP than in NBP (NC16A 18% vs. 9%, P = 0.139; BP230 34% vs. 22%, P = 0.149). IgE ELISAs for NC16A and BP230 were positive in 8% and 20% of elderly controls, respectively, while all pemphigus controls were negative. Two of 28 biopsies (7%; one NBP, one BP) showed linear IgE along the basement membrane zone, while in most biopsies (71% NBP; 86% BP) IgE was bound to dermal cells. Conclusion Since IgE was present in the serum and skin of both NBP and BP patients, this supports IgE-dependent mechanisms common to both diseases, such as pruritus. However, it remains to be elucidated whether IgE contributes to blister formation in BP

An Unusual Transmission Spectrum for the Sub-Saturn KELT-11b Suggestive of a Sub-Solar Water Abundance

We present an optical-to-infrared transmission spectrum of the inflated sub-Saturn KELT-11b measured with the Transiting Exoplanet Survey Satellite (TESS), the Hubble Space Telescope (HST) Wide Field Camera 3 G141 spectroscopic grism, and the Spitzer Space Telescope (Spitzer) at 3.6 $\mu$m, in addition to a Spitzer 4.5 $\mu$m secondary eclipse. The precise HST transmission spectrum notably reveals a low-amplitude water feature with an unusual shape. Based on free retrieval analyses with varying molecular abundances, we find strong evidence for water absorption. Depending on model assumptions, we also find tentative evidence for other absorbers (HCN, TiO, and AlO). The retrieved water abundance is generally $\lesssim 0.1\times$ solar (0.001--0.7$\times$ solar over a range of model assumptions), several orders of magnitude lower than expected from planet formation models based on the solar system metallicity trend. We also consider chemical equilibrium and self-consistent 1D radiative-convective equilibrium model fits and find they too prefer low metallicities ($[M/H] \lesssim -2$, consistent with the free retrieval results). However, all the retrievals should be interpreted with some caution since they either require additional absorbers that are far out of chemical equilibrium to explain the shape of the spectrum or are simply poor fits to the data. Finally, we find the Spitzer secondary eclipse is indicative of full heat redistribution from KELT-11b's dayside to nightside, assuming a clear dayside. These potentially unusual results for KELT-11b's composition are suggestive of new challenges on the horizon for atmosphere and formation models in the face of increasingly precise measurements of exoplanet spectra.Comment: Accepted to The Astronomical Journal. 31 pages, 20 figures, 7 table

Transmembrane potential induced on the internal organelle by a time-varying magnetic field: a model study

<p>Abstract</p> <p>Background</p> <p>When a cell is exposed to a time-varying magnetic field, this leads to an induced voltage on the cytoplasmic membrane, as well as on the membranes of the internal organelles, such as mitochondria. These potential changes in the organelles could have a significant impact on their functionality. However, a quantitative analysis on the magnetically-induced membrane potential on the internal organelles has not been performed.</p> <p>Methods</p> <p>Using a two-shell model, we provided the first analytical solution for the transmembrane potential in the organelle membrane induced by a time-varying magnetic field. We then analyzed factors that impact on the polarization of the organelle, including the frequency of the magnetic field, the presence of the outer cytoplasmic membrane, and electrical and geometrical parameters of the cytoplasmic membrane and the organelle membrane.</p> <p>Results</p> <p>The amount of polarization in the organelle was less than its counterpart in the cytoplasmic membrane. This was largely due to the presence of the cell membrane, which "shielded" the internal organelle from excessive polarization by the field. Organelle polarization was largely dependent on the frequency of the magnetic field, and its polarization was not significant under the low frequency band used for transcranial magnetic stimulation (TMS). Both the properties of the cytoplasmic and the organelle membranes affect the polarization of the internal organelle in a frequency-dependent manner.</p> <p>Conclusions</p> <p>The work provided a theoretical framework and insights into factors affecting mitochondrial function under time-varying magnetic stimulation, and provided evidence that TMS does not affect normal mitochondrial functionality by altering its membrane potential.</p

High-frequency irreversible electroporation (H-FIRE) for non-thermal ablation without muscle contraction

<p>Abstract</p> <p>Background</p> <p>Therapeutic irreversible electroporation (IRE) is an emerging technology for the non-thermal ablation of tumors. The technique involves delivering a series of unipolar electric pulses to permanently destabilize the plasma membrane of cancer cells through an increase in transmembrane potential, which leads to the development of a tissue lesion. Clinically, IRE requires the administration of paralytic agents to prevent muscle contractions during treatment that are associated with the delivery of electric pulses. This study shows that by applying high-frequency, bipolar bursts, muscle contractions can be eliminated during IRE without compromising the non-thermal mechanism of cell death.</p> <p>Methods</p> <p>A combination of analytical, numerical, and experimental techniques were performed to investigate high-frequency irreversible electroporation (H-FIRE). A theoretical model for determining transmembrane potential in response to arbitrary electric fields was used to identify optimal burst frequencies and amplitudes for <it>in vivo </it>treatments. A finite element model for predicting thermal damage based on the electric field distribution was used to design non-thermal protocols for <it>in vivo </it>experiments. H-FIRE was applied to the brain of rats, and muscle contractions were quantified via accelerometers placed at the cervicothoracic junction. MRI and histological evaluation was performed post-operatively to assess ablation.</p> <p>Results</p> <p>No visual or tactile evidence of muscle contraction was seen during H-FIRE at 250 kHz or 500 kHz, while all IRE protocols resulted in detectable muscle contractions at the cervicothoracic junction. H-FIRE produced ablative lesions in brain tissue that were characteristic in cellular morphology of non-thermal IRE treatments. Specifically, there was complete uniformity of tissue death within targeted areas, and a sharp transition zone was present between lesioned and normal brain.</p> <p>Conclusions</p> <p>H-FIRE is a feasible technique for non-thermal tissue ablation that eliminates muscle contractions seen in IRE treatments performed with unipolar electric pulses. Therefore, it has the potential to be performed clinically without the administration of paralytic agents.</p