Segmentation and kinematics of the North America-Caribbean plate boundary offshore Hispaniola

We explored the submarine portions of the Enriquillo–Plantain Garden Fault zone (EPGFZ) and the Septentrional–Oriente Fault zone (SOFZ) along the Northern Caribbean plate boundary using high-resolution multibeam echo-sounding and shallow seismic reflection. The bathymetric data shed light on poorly documented or previously unknown submarine fault zones running over 200 km between Haiti and Jamaica (EPGFZ) and 300 km between the Dominican Republic and Cuba (SOFZ). The primary plate-boundary structures are a series of strike-slip fault segments associated with pressure ridges, restraining bends, step overs and dogleg offsets indicating very active tectonics. Several distinct segments 50–100 km long cut across pre-existing structures inherited from former tectonic regimes or bypass recent morphologies formed under the current strike-slip regime. Along the most recent trace of the SOFZ, we measured a strike-slip offset of 16.5 km, which indicates steady activity for the past ~1.8 Ma if its current GPS-derived motion of 9.8 ± 2 mm a−1 has remained stable during the entire Quaternary.

Classifying image analysis techniques from their output

In this paper we discuss some main image processing techniques in order to propose a classification based upon the output these methods provide. Because despite a particular image analysis technique can be supervised or unsupervised, and can allow or not the existence of fuzzy information at some stage, each technique has been usually designed to focus on a specific objective, and their outputs are in fact different according to each objective. Thus, they are in fact different methods. But due to the essential relationship between them they are quite often confused. In particular, this paper pursues a clarification of the differences between image segmentation and edge detection, among other image processing techniques.

Employment status and health in Spain before and after the Great Recession

This article analyzes the relationship between employment status (ES), on one hand, and self-rated health and psychological distress, on the other, in the context of the Great Recession beginning in 2008. For this purpose, it is necessary to move beyond the employment/unemployment dichotomy characteristics of previous theories and research concerning the relationship between the labor market, recession, and health. The authors use data from the Spanish National Health Surveys in 2006 (n = 15,128), before the crisis, and in 2012 (n = 11,124), when its consequences had taken effect. The results of the regression analysis indicate a structural change in the relationship between ES and health. Health inequality patterns changed during the crisis, with increased deterioration in the health of unemployed, especially the long-term unemployed, and self-employed workers. Health inequalities were reduced for temporary workers. The results support the idea that the structure of the association between ES and health varies according to the economic cycle. The association between recession, ES, and health would be directly related to the specific characteristics of the economic and employment contexts under study. In the Spanish case, labor market segmentation processes based on numerical flexibility—a key feature of the Mediterranean Variety of Capitalism—may explain the results obtained.

A methodology for hierarchical image segmentation evaluation

This paper proposes a method to evaluate hierarchical image segmentation procedures, in order to enable comparisons between different hierarchical algorithms and of these with other (non-hierarchical) segmentation techniques (as well as with edge detectors) to be made. The proposed method builds up on the edge-based segmentation evaluation approach by considering a set of reference human segmentations as a sample drawn from the population of different levels of detail that may be used in segmenting an image. Our main point is that, since a hierarchical sequence of segmentations approximates such population, those segmentations in the sequence that best capture each human segmentation level of detail should provide the basis for the evaluation of the hierarchical sequence as a whole. A small computational experiment is carried out to show the feasibility of our approach.