New approaches in urban simulation and city planning using virtual reality tools

Peer Reviewe

La fuerza creativa de la determinación. La obra creativa de María Antonia de Paz y Figueroa

La expulsión de la orden religiosa de los Jesuitas de América Latina en el siglo XVIII tuvo diferentes consecuencias políticas y religiosas en la sociedad de la época. E influyó, así mismo, en la determinación y en las acciones de la Beata María Antonia de Paz en Argentina, que desarrolló una serie de ejercicios espirituales y una red de solidaridad en torno a ellos intentando suplir la ausencia de la orden. El presente artículo intenta analizar los ejercicios religiosos, implantación en Argentina y sus consecuencias tanto en las comunidades religiosas y laicas de América, como en las europeas. El trabajo se centra en la correspondencia de esta mujer religiosa con los Jesuitas expulsados y en el rigor y la disciplina que manifestó ante la crisis y que permitieron la reforma de distintos conventos en Europa. El artículo, desde una perspectiva histórica, muestra la lucidez de la Beata consistente en detectar un espacio de déficit espiritual y asumir el poder vacante desde la partida de los Jesuitas

Characteristics of Mesoscale and Submesoscale Eddies in the Labrador Sea: Observations vs. Model

Mesoscale eddies play an important role in lateral property fluxes. Observational studies often use sea level anomaly maps from satellite altimetry to estimate eddy statistics (incl. eddy kinetic energy). Recent findings suggest that altimetry derived eddy characteristics may suffer from the low spatial resolution of past and current satellite-tracks in high-latitude oceans associated with small Rossby radii. This study presents results of an eddy reconstruction that provides an alternative perspective on the eddy field based on a nonlinear, damping Gauss-Newton optimisation algorithm using ship-based current profiler observations from two research expeditions in the Labrador Sea in 2014 and 2018. The derived eddy characteristics are compared to the high-resolution submesoscale permitting NATL60 model (1/60°). Overall, a total of 14 eddies with radii ranging from 7 to 35km and azimuthal velocities ranging from 20 to 60 cm s−1 were detected, of which 3 eddies were identified as Irminger rings. Irminger rings are characterised by a warm, salty lens either surface trapped or overlaid by a cold, fresh cap of water. The modelled eddies are on average 25% smaller in radius and 20% higher in azimuthal velocity accompanied by increased nonlinearity. The inner ring velocity structure for observations and NATL60 suggests solid-body rotation for 1/2 to 2/3 of the radius. The eddy boundary and outer ring velocity structure follows a more Gaussian-like shape, best described by a exp(−r2) dependency. Furthermore, the maximum azimuthal velocity may deviate from solid-body rotation by more than 30% for the observations and 50% for the model. In order to verify the skill of eddy reconstruction, the NATL60 served as a reference data set for the skill assessment of the Gauss-Newton method. It is shown that the eddy characteristics are affected by the location of the ship track through the velocity field. In most cases, however, the derived properties are not expected to deviate by more than 10%. Spectral analysis of the horizontal velocity implies that the mesoscale regime is well represented in NATL60 compared with the observations. The representation of the submesoscale flow decreases in the model with increasing depth. In particular, observations and model spectra diverge in the pycnocline by roughly one order of magnitude at scales smaller than 50km. Besides, the transition of power spectra slopes from k−2 to k−3 in ship-based measurements and model suggests a weak seasonal signal

New approaches in urban simulation and city planning using virtual reality tools

Peer Reviewe

Investigation of hypoxia in syngeneic rat prostate tumors after irradiation with photons or carbon ions by multimodal imaging and histology

Tumor hypoxia has been widely recognized as a significant factor that increases treatment resistance and promotes malignant progression. High linear energy transfer (LET) radiotherapy (RT), e.g. with carbon ions (12C-ions), is expected to overcome this resistance factors as its lethality is less dependent on tumor oxygenation as compared to conventional low LET photon irradiation. However, the exact interplay between irradiation response, vascular changes, perfusion, and hypoxia is still not well understood, especially with respect to high LET RT. In the present thesis, the hypoxic status of syngeneic Dunning R3327 rat prostate tumor model sublines was characterized prior to and after irradiation with either low LET photons or high LET 12C-ions by multimodal imaging and histology. The initial oxygenation status of three subcutaneously transplanted Dunning tumor sublines (H, HI and AT1) was determined by photoacoustic imaging (PAI) which included the development and validation of a new PAI analysis protocol. The new protocol enabled the distinction of the three sublines based on their oxygenation profiles and their response towards external changes in oxygen supply. Subsequently, the effects of curative and sub-curative single dose irradiations with either photons or 12C-ions on the two hypoxic tumor sublines (HI and AT1) were investigated by pharmacokinetic modeling of longitudinal dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data. For this, a novel method for estimating the contrast agent’s arrival time was developed in cooperation with the group for Image Analysis and Learning of the Interdisciplinary Center for Scientific Computing of Heidelberg University. It enables a delay correction of the contrast agent arrival time which improves fit accuracy and the reliability of the pharmacokinetic modeling results. The moderately differentiated HI-tumor showed increased vascular permeability 7 days after irradiation without any modality or dose dependency, while the anaplastic and chronic hypoxic AT1-tumor revealed an earlier and stronger treatment response after 12C-ion irradiation as compared to the more delayed response after photon irradiation. Again, no dose dependency was detected. Finally, a longitudinal histology study after irradiation of the AT1-tumor with curative doses of either photons or 12C-ions revealed that hypoxia developed slightly faster after 12C-ion than after photon irradiation. Furthermore, this study validated the relative biological effectiveness (RBE) for 12C-ions, which was determined previously for the endpoint local tumor control, on a microscopic level within the first 10 days. Additionally, reasonable time points for a future multimodal imaging study with PAI, sequential positron emission tomography (PET) and DCE-MRI measurements as well as histology were determined. In conclusion, this thesis proved PAI and the novel analysis protocol to be a feasible method for the characterization of the three Dunning tumor sublines with respect to their oxygenation. The different sensitivities of the HI- and AT1-tumors towards the two irradiation modalities indicate that the irradiation-induced vascular response depends on the structural-functional status of the tumor vasculature. The dose-independent response of both tumor sublines towards the two irradiation modalities suggests that the initial vascular response only plays a minor role with respect to local tumor control at high single doses