Symbolic modeling of structural relationships in the Foundational Model of Anatomy

The need for a sharable resource that can provide deep anatomical knowledge and support inference for biomedical applications has recently been the driving force in the creation of biomedical ontologies. Previous attempts at the symbolic representation of anatomical relationships necessary for such ontologies have been largely limited to general partonomy and class subsumption. We propose an ontology of anatomical relationships beyond class assignments and generic part-whole relations and illustrate the inheritance of structural attributes in the Digital Anatomist Foundational Model of Anatomy. Our purpose is to generate a symbolic model that accommodates all structural relationships and physical properties required to comprehensively and explicitly describe the physical organization of the human body

A Survey on Negative Transfer

Transfer learning (TL) tries to utilize data or knowledge from one or more source domains to facilitate the learning in a target domain. It is particularly useful when the target domain has few or no labeled data, due to annotation expense, privacy concerns, etc. Unfortunately, the effectiveness of TL is not always guaranteed. Negative transfer (NT), i.e., the source domain data/knowledge cause reduced learning performance in the target domain, has been a long-standing and challenging problem in TL. Various approaches to handle NT have been proposed in the literature. However, this filed lacks a systematic survey on the formalization of NT, their factors and the algorithms that handle NT. This paper proposes to fill this gap. First, the definition of negative transfer is considered and a taxonomy of the factors are discussed. Then, near fifty representative approaches for handling NT are categorized and reviewed, from four perspectives: secure transfer, domain similarity estimation, distant transfer and negative transfer mitigation. NT in related fields, e.g., multi-task learning, lifelong learning, and adversarial attacks are also discussed

Facial attractiveness among rhesus macaques (Macaca mulatta) : manipulating and measuring preferences for conspecifics' facial characteristics

The face holds a central role in both human and nonhuman primate social interactions, through the communication of feelings and intentions via facial expressions and by acting as a means of recognising individuals. Humans, however, also employ their faces in mate attraction and assessment, an area that has received little attention in nonhuman primates. Many researchers have proposed that human aesthetic judgments of facial attractiveness have a biological basis, and these preferences have evolved via sexual selection processes during human evolution. The use of the face in attractiveness assessments need not be limited to humans. Rather, there is good reason to suggest that this may also apply to other nonhuman primates, based on homologies in the way in which primates use their faces, and on evidence that the face is a site of sexual selection for many primate species. It was the aim of this thesis to explore whether facial traits may also play a role in judgements of attractiveness in a nonhuman primate, the rhesus macaque( Macaca mulatta), in an effort to understand whether humans are unique in utilising the face as a mechanism of mate assessment. Three factors that are reported to influence facial attractiveness in humans are facial symmetry, sexual dimorphism, and averageness. To assess whether they also play a role in nonhuman primates, a series of experiments were conducted where digital images of adult male and female rhesus macaque faces were altered for these features. Opposite-sexed images were then displayed to adult males and females in a captive setting. Eye gaze measures were utilised to assess visual preference for, and the relative importance of, these traits. These experiments yielded mixed results. Increasing facial symmetry of opposite-sexed conspecifics positively influenced the dependent gaze measures employed here. Manipulating degree of facial sexual dimorphism had little influence on the visual gaze of either sex. Facial averageness positively influenced visual preferences for opposite-sexed conspecifics among both sexes, although increasing degree of averageness did not. The last topic to be explored was facial colouration. Rhesus macaques like, various other species of anthropoid primates, possess facial displays of red secondary sexual colouration. As above, animals viewed digitally altered pale and red versions of opposite-sexed conspecifics. Although females displayed preferences for red male faces, males displayed no clear preferences based on female facial colour. This raises the possibility that male and female facial colour may serve different roles in intraspecific signaling. While it cannot be concluded that visual preferences are indeed indicative of real-life preferences, the results do indicate that animals are not indifferent to variations in conspecific facial features. The present findings have important implications regarding the evolution of facial attractiveness, as they provide the first experimental evidence suggesting that facial features may serve as a mechanism for mate selection across primate taxa and that both human and nonhuman primates may employ similar criteria to appraise facial attractiveness

Nuclei & Glands Instance Segmentation in Histology Images: A Narrative Review

Instance segmentation of nuclei and glands in the histology images is an important step in computational pathology workflow for cancer diagnosis, treatment planning and survival analysis. With the advent of modern hardware, the recent availability of large-scale quality public datasets and the community organized grand challenges have seen a surge in automated methods focusing on domain specific challenges, which is pivotal for technology advancements and clinical translation. In this survey, 126 papers illustrating the AI based methods for nuclei and glands instance segmentation published in the last five years (2017-2022) are deeply analyzed, the limitations of current approaches and the open challenges are discussed. Moreover, the potential future research direction is presented and the contribution of state-of-the-art methods is summarized. Further, a generalized summary of publicly available datasets and a detailed insights on the grand challenges illustrating the top performing methods specific to each challenge is also provided. Besides, we intended to give the reader current state of existing research and pointers to the future directions in developing methods that can be used in clinical practice enabling improved diagnosis, grading, prognosis, and treatment planning of cancer. To the best of our knowledge, no previous work has reviewed the instance segmentation in histology images focusing towards this direction.Comment: 60 pages, 14 figure

Neural mechanisms of visual categorization

The ability to categorize is a fundamental cognitive skill for animals, including human beings. Our lives would be utterly confusing without categories. We would feel overwhelmed or miss out on important aspects of our environment if we would perceive every single entity as one-of-a-kind. Therefore, categorization is of great importance for perception, learning, remembering, decision making, performing an action, certain aspects of social interaction, and reasoning. The seemingly effortless and instantaneous ability to transform sensory information into meaningful categories determines the success for interacting with our environment. However, the apparent ease with which we use categorization and categories conceals the complexity of the underlying brain processing that makes categorization and categorical representations possible. Therefore, the question arises: how are categorical information encoded and represented in the brain

Visual Patterns in the Perception of Abstract and Social Stimuli

This thesis investigated with regard to the perception of abstract and social stimuli: (1) What constitutes a visual pattern? (2) Whether people possess a proclivity towards one particular pattern type. (3) When is patterning imposed or detected by the visual system? The abstract stimuli consisted of checkerboard patterns and the social stimuli consisted of faces or social groups. Initially the term "pattern" was defined as an image that contains redundant information. This was illustrated by a bias when defining patterns by members of the public towards images that contain both repeated and reflective symmetry, or a low number of possible variants and therefore reduced information content, i. e. more redundancy. Similarly reflective symmetry was identified as a key property in defining faces. The effect of symmetry type on early visual processing was investigated further in a series of backward masking experiments on both abstract and facial stimuli (Chapters 6& 7). The results of the masking experiments suggest a bias during early visual processing for patterns that contain symmetry (i. e. repetition or reflection), or share common fate compared with randomly generated patterns or distorted faces. A top-hemifield and LVF bias was observed in the early detection of patterns. Patterns that take advantage of these properties such as the eyes within the face were suggested as having a perceptual advantage. Patterning appears to be imposed at all stages of visual processing. At early stages of visual processing, repetition (and in the face the eyes) was observed as having an early perceptual advantage over reflection (and in the face the mouth). However at later stages of processing repetition appeared to be processed serially and no longer had a perceptual advantage over reflection (ISIs >42ms). Reflection was suggested as having a perceptual advantage post V1 (ISIs >96ms). Patterning continues throughout a visual scene from the local level to the global level, as such both the human face and human social groups can be perceived as patterns. This was illustrated by a series of experiments investigating the effect of patterning on the perception of images presented in the periphery of a scene (Chapter 8)