19 research outputs found
Analysis and Overall Evaluation of Latin American Trade Policies
Development thlnking and practive in Latin America have been strongly influenced by the centre-periphery approach with its heavy emphasis on international trade, considered the most important variable in the analytical explanation of the origin of underdevelopment as well as in the strategy recommended for its elimination
Denoising diffusion-based MR to CT image translation enables whole spine vertebral segmentation in 2D and 3D without manual annotations
Background: Automated segmentation of spinal MR images plays a vital role
both scientifically and clinically. However, accurately delineating posterior
spine structures presents challenges.
Methods: This retrospective study, approved by the ethical committee,
involved translating T1w and T2w MR image series into CT images in a total of
n=263 pairs of CT/MR series. Landmark-based registration was performed to align
image pairs. We compared 2D paired (Pix2Pix, denoising diffusion implicit
models (DDIM) image mode, DDIM noise mode) and unpaired (contrastive unpaired
translation, SynDiff) image-to-image translation using "peak signal to noise
ratio" (PSNR) as quality measure. A publicly available segmentation network
segmented the synthesized CT datasets, and Dice scores were evaluated on
in-house test sets and the "MRSpineSeg Challenge" volumes. The 2D findings were
extended to 3D Pix2Pix and DDIM.
Results: 2D paired methods and SynDiff exhibited similar translation
performance and Dice scores on paired data. DDIM image mode achieved the
highest image quality. SynDiff, Pix2Pix, and DDIM image mode demonstrated
similar Dice scores (0.77). For craniocaudal axis rotations, at least two
landmarks per vertebra were required for registration. The 3D translation
outperformed the 2D approach, resulting in improved Dice scores (0.80) and
anatomically accurate segmentations in a higher resolution than the original MR
image.
Conclusion: Two landmarks per vertebra registration enabled paired
image-to-image translation from MR to CT and outperformed all unpaired
approaches. The 3D techniques provided anatomically correct segmentations,
avoiding underprediction of small structures like the spinous process.Comment: 35 pages, 7 figures, Code and a model weights available
https://doi.org/10.5281/zenodo.8221159 and
https://doi.org/10.5281/zenodo.819869
Europa y América Latina en la crisis mundial
A deep crisis has shaken the world economy since the early 1970s; even the recent improvements in the situation in some countries accentuate the extension of the crisis and the basic structural inequalities that characterize the world economy. This work is divided into four parts that deal with the causes of the crisis, its effects in Europe and Latin America, and, finally, how it has affected relations between Europe and Latin America. We argue that both regions have reached a crossroads and are faced with a great challenge: Europe can be helped by, and in turn can help, Latin America, since if Latin America's hope for independence today passes through Europe, the economic future of Europe also passes through Latin America.Una profunda crisis ha sacudido la economía mundial desde principios de la década de los años 70; aún las recientes mejorías en la situación de algunos países acentúan la extensión de la crisis y las desigualdades estructurales básicas que caracterizan la economía mundial. Este trabajo está dividido en cuatro partes que tratan las causas de la crisis, sus efectos en Europa y América Latina, y, finalmente, cómo esta ha afectado las relaciones entre Europa y América Latina. Sostenemos que ambas regiones han llegado a una encrucijada y se ven enfrentadas a un gran desafío: Europa puede ser ayudada por, y a su vez puede ayudar a América Latina, ya que si la esperanza de América Latina de independizarse hoy día pasa a través de Europa, el futuro económico de Europa también pasa a través de América Latina
The World economy : the crisis in financial markets and the risk of a global depression
The risk of a new Great Depression is greater now than at any time during the last two decades. Although the immediate cause of the risk is the Asian crisis, its deeper causes are rooted in the economic system that prevails in most countries and the related global network that increasingly embraces them all. The current globalisation was preceded by a similar phenomenon at the turn of the present century, a phenomenon that ended under the forces of growing inequality and destructive competition. Both cases of globalisation are characterised by fundamentally flawed banking systems: a series of financial panics in South America and Central Europe brought to an end the first, those in Asia and Russia are undermining the second. The identification and analysis of the process that has shaped the world economy and brought it to the present crossroad is essential for moving away from the brink of a new disaster. The main instruments to achieve this objective are found to be the state, and its revamped role, and regionalism