Towards Debiasing Fact Verification Models

Fact verification requires validating a claim in the context of evidence. We show, however, that in the popular FEVER dataset this might not necessarily be the case. Claim-only classifiers perform competitively with top evidence-aware models. In this paper, we investigate the cause of this phenomenon, identifying strong cues for predicting labels solely based on the claim, without considering any evidence. We create an evaluation set that avoids those idiosyncrasies. The performance of FEVER-trained models significantly drops when evaluated on this test set. Therefore, we introduce a regularization method which alleviates the effect of bias in the training data, obtaining improvements on the newly created test set. This work is a step towards a more sound evaluation of reasoning capabilities in fact verification models.Comment: EMNLP IJCNLP 201

Non-Proportional Medical Interventions at the End of Life in a High Complexity Hospital in Colombia

Objetivo: Analizar las intervenciones realizadas en una cohorte de pacientes fallecidos en un hospital universitario de alta complejidad y definir la proporcionalidad terapéutica de las mismas, a partir del estudio de la prevalencia de “tratamientos no benéficos”. Metodología Estudio observacional descriptivo retrospectivo, basado en la revisión de historias clínicas de los pacientes fallecidos en el periodo de dos años en un hospital universitario de alta complejidad Resultados: Se analizaron 931 historias de pacientes fallecidos y en la categorización de acuerdo con el criterio de “proporcionalidad terapéutica” se encontró que en el 54,7% de los pacientes se realizaron intervenciones diagnosticas o terapéuticas clasificadas como “desproporcionadas” de acuerdo con la definición aplicada. Conclusión: En la práctica las intervenciones no proporcionales o no benéficas al final de la vida son prevalentes, lo que constituye un problema mayor y persistente, a pesar de sus repercusiones negativas sobre los pacientes, las familias, los profesionales de la salud y el sistema de saludPurpose: To analyze the interventions carried out in a cohort of patients who died in a university hospital of highcomplexity and define their therapeutic proportionality, based on the study of the prevalence of "non-beneficialtreatments". Methodology: Retrospective descriptive observational study, based on the review of medical records of patients who died in a two-year period in a highly complex university hospital. Results: 931 records of deceased patients were analyzed and categorized according to the criteria of “ therapeutic proportionality ”. It was found that 54.7% of the patients underwent diagnostic or therapeutic interventions classified as “disproportionate” according to the applied definition. Conclusion: In practice, non-proportional or non-beneficial end-of-lifeinterventions are prevalent, which is a major and persistent problem, despite the negative impact on patients,families, health professionals and the health system.Revista Nacional - Indexad

Anisotropic Material Properties of Wild-Type and Tectb−/− Tectorial Membranes

The tectorial membrane (TM) is an extracellular matrix that is directly coupled with the mechanoelectrical receptors responsible for sensory transduction and amplification. As such, the TM is often hypothesized to play a key role in the remarkable sensory abilities of the mammalian cochlea. Genetic studies targeting TM proteins have shown that changes in TM structure dramatically affect cochlear function in mice. Precise information about the mechanical properties of the TMs of wild-type and mutant mice at audio frequencies is required to elucidate the role of the TM and to understand how these genetic mutations affect cochlear mechanics. In this study, images of isolated TM segments are used to determine both the radial and longitudinal motions of the TM in response to a harmonic radial excitation. The resulting longitudinally propagating radial displacement and highly spatially dependent longitudinal displacement are modeled using finite-element models that take into account the anisotropy and finite dimensions of TMs. An automated, least-square fitting algorithm is used to find the anisotropic material properties of wild-type and Tectb−/− mice at audio frequencies. Within the auditory frequency range, it is found that the TM is a highly viscoelastic and anisotropic structure with significantly higher stiffness in the direction of the collagen fibers. Although no decrease in the stiffness in the fiber direction is observed, the stiffness of the TM in shear and in the transverse direction is found to be significantly reduced in Tectb−/− mice. As a result, TMs of the mutant mice tend to be significantly more anisotropic within the frequency range examined in this study. The effects of the Tectb−/− mutation on the TM’s anisotropic material properties may be responsible for the changes in cochlear tuning and sensitivity that have been previously reported for these mice.National Institutes of Health (Grant R01-DC000238

Age-related degradation of tectorial membrane dynamics with loss of CEACAM16

Studies of genetic disorders of sensorineural hearing loss have been instrumental in delineating mechanisms that underlie the remarkable sensitivity and selectivity that are hallmarks of mammalian hearing. For example, genetic modifications of TECTA and TECTB, which are principal proteins that comprise the tectorial membrane (TM), have been shown to alter auditory thresholds and frequency tuning in ways that can be understood in terms of changes in the mechanical properties of the TM. Here, we investigate effects of genetic modification targeting CEACAM16, a third important TM protein. Loss of CEACAM16 has been recently shown to lead to progressive reductions in sensitivity. Whereas age-related hearing losses have previously been linked to changes in sensory receptor cells, the role of the TM in progressive hearing loss is largely unknown. Here, we show that TM stiffness and viscosity are significantly reduced in adult mice that lack functional CEACAM16 relative to age-matched wild-type controls. By contrast, these same mechanical properties of TMs from juvenile mice that lack functional CEACAM16 are more similar to those of wild-type mice. Thus, changes in hearing phenotype align with changes in TM material properties and can be understood in terms of the same TM wave properties that were previously used to characterize modifications of TECTA and TECTB. These results demonstrate that CEACAM16 is essential for maintaining TM mechanical and wave properties, which in turn are necessary for sustaining the remarkable sensitivity and selectivity of mammalian hearing with increasing age