Decoding visual object categories in early somatosensory cortex

Neurons, even in the earliest sensory areas of cortex, are subject to a great deal of contextual influence from both within and across modality connections. In the present work, we investigated whether the earliest regions of somatosensory cortex (S1 and S2) would contain content-specific information about visual object categories. We reasoned that this might be possible due to the associations formed through experience that link different sensory aspects of a given object. Participants were presented with visual images of different object categories in 2 fMRI experiments. Multivariate pattern analysis revealed reliable decoding of familiar visual object category in bilateral S1 (i.e., postcentral gyri) and right S2. We further show that this decoding is observed for familiar but not unfamiliar visual objects in S1. In addition, whole-brain searchlight decoding analyses revealed several areas in the parietal lobe that could mediate the observed context effects between vision and somatosensation. These results demonstrate that even the first cortical stages of somatosensory processing carry information about the category of visually presented familiar objects

Construction and testing of self-drilled soil nails

Current standards and best practice guidance recognise that testing of self-drilled hollow bar soil nails can be problematic as conventional packers and debonded lengths cannot be constructed. As a result, this causes difficulty in testing and confirming the ultimate bond resistance within the passive zone of a soil-nailed slope, and thus the design soil nail lengths. This paper provides a summary and review of the various testing procedures adopted for a soil nail construction project in Scotland. The practical design considerations, and their validation through the installation and testing of 49 sacrificial test nails, are detailed. The construction issues associated with the nail installation and testing are also outlined and discussed in light of the results obtained using different testing approaches. The aim of this case study is to report on the experiences with installation and testing of hollow bar soil nails. The objectives are to develop an initial data base of available soil–grout bond strength of hollow bar soil nails based on the several practical installation procedures used in this project and to establish areas for improvement of installation, testing and quality control in order to perform comparable pullout tests on self-drilled hollow bar soil nails. </jats:p

Learning person-specific knowledge about new people.

Much progress has been made in the last twenty years or so on understanding the cognitive processes involved in familiar person recognition (see, for instance, Burton, Bruce, and Hancock, 1999). Indeed both Burton and colleagues (Burton et al., 1999) and Bredart and colleagues (Bredart, Valentine, Calder, Gassi, 1995) have proposed implemented models of several aspects of familiar person recognition. Yet models such as these presuppose the prior process of person familiarisation. A satisfactory theory of person processing needs to address not only familiar person processing but also unfamiliar person processing, and most critically, the familiarisation process which bridges the gap between these two categories. There is much evidence to suggest, moreover, that familiar and unfamiliar people are processed by the cognitive system in different ways. Yet studies investigating the gradual transition phase by which a person changes from being unfamiliar to being highly familiar are relatively rare. Some research has been carried out on the perceptual changes which accompany familiarisation (e.g. O’Donnell & Bruce, 2001). Perceptual change, however, is only one component of familiarisation. The other critical component is forming knowledge about the individual (i.e. semantic knowledge). There has hardly been any research on semantic familiarisation to date. The aim of this thesis is to obtain evidence pertaining to the issue of semantic familiarisation which should constrain future models of person processing. I review models of familiar person recognition in chapter one of the present thesis and further identify the gap existing in the literature with respect to semantic aspects of familiarisation. I also offer arguments as to the intrinsic importance of including familiarisation in any theory of person processing. The first experimental chapter investigates, by means of both verification and cued-recall tasks, whether a script-like representation of person-specific knowledge may prove more fruitful than current mechanisms of representing such knowledge in the course of learning about new people. I conclude that an explanation in terms of general memory theory best fits the results obtained in this chapter. The second experimental chapter moves away from the learning methodology used in first chapter to employ a much more ecologically valid learning paradigm. That is, as opposed to using one simple face image and a set of semantic properties I use an initially unfamiliar soap opera with which participants gradually become familiarised. I consider the structure of person-specific knowledge for both a set of famous people and further a set of characters from the soap opera. Results here suggest that occupations are the important category for famous persons but that, for a newly learned set of individuals, relational information is more important. I again examine these questions using both recall and verification tasks in this chapter. I argue that one critical factor in determining preferential representation of a given type of information in the representation of person-specific knowledge for some person is the co-occurrence frequency of encountering that person with that class of information. The final experimental chapter (Chapter 4) attempts to investigate the processes of semantic familiarisation in an on-line manner. I use a self-priming paradigm (see Calder & Young, 1996) to probe the development of participants’ semantic representations at regular intervals across a learning period. I report both within-domain and cross-domain experiments addressing this issue. Results indicate that after a relatively short interval newly learned persons behave comparably to famous persons in several important respects. Existing theories of general memory (e.g. Logan, 1988; McClelland & Chappell, 1998) account well for the perceptual familiarisation which occurs in the reported experiments. Further development is required, however, to account for the results on semantic familiarisation. I summarise and evaluate the experiments reported in the present thesis in the final chapter and also attempt some theoretical development which should provide useful for the creation of a unified theory of person processing

The Magnetic Field Gradiometer

Final Technical Report No. E723-1This report has two principal goals: First, to present a general review of magnetic field gradiometers and, second, to provide new data concerning these gradiometers, including new information about their response to magnetic dipole fields. A system of nomenclature is introduced that is consistent with the mathematical concept of gradient and which provides a basis for discussions of the different functions of magnetic field gradiometers and differential magnetometers. The distinction between component gradiometers and total field gradiometers is also stressed. An historical review provides an opportunity to describe the different characteristics of the many kinds of magnetic field gradiometers that have been developed since the first report of such a gradiometer in 1925: rotating induction loop, fixed induction loop, fluxgate, proton precession, optically pumped, and superconducting gradiometers are discussed. It is pointed out how the great sensitivity of superconducting gradiometers, and possibly other varieties of modern magnetic field gradiometers, may invalidate the popular 'source-free' asssumption under particular circumstances. Further, because these high sensitivities will make the gradiometers more susceptible to the geomagnetic field gradient, expressions are derived for the components of this gradient and some representative numerical values are calculated. The response of both component and total field gradiometers to dipole sources is considered for a number of different source-gradiometer configurations. On a more speculative note, two varieties of rotating component gradiometers are discussed, with particular attention being given to their possibly unique characteristics. The report ends by recapitulating the many applications of magnetic field gradiometers, particularly in such important areas as medicine, energy production, and defense, and by stressing the need for gradiometer-related basic research.Office of Naval TechnologyNaval Postgraduate SchoolOffice of Naval ResearchN00228-81-C-AB56Approved for public release; distribution is unlimited

The Magnetic Field Gradiometer

This report has two principal goals. First, to present a general review of magnetic field gradiometers and, second, to provide new data concerning these gradiometers, including new information about their response to magnetic dipole fields. A system of nomenclature is introduced that is consistent with the mathematical concept of gradient and which provides a basis for discussions of the different functions of magnetic field gradiometers and differential magnetometers. The distinction between component gradiometers and total field gradiometers is also stressed.Office of Naval TechnologyNaval Postgraduate SchoolOffice of Naval ResearchAdditional support for this work was provided by the Office of Naval Research through Contracts No.N00014-75-C-1095 and N00014-77-C-0292.Approved for public release; distribution unlimited

Pet owner and vet interactions: exploring the drivers of AMR

Background: Antimicrobial resistance (AMR) is a growing public health problem across the world. As the negative consequences of AMR become apparent at local, national and international levels, more attention is being focussed on the variety of mechanisms by which AMR is potentiated. We explore how interactions between pet owners and veterinarians represent a key arena in which AMR-related behaviours can be shaped. Methods: In depth semi-structured interviews were carried out with pet owners (n = 23) and vets (n = 16) across the UK in 2017. A thematic analysis approach was taken, with inductively gathered data analysed deductively using a behavioural framework to identified key behaviours emerging from participant accounts which were amenable to change. Results: Interactions between vets and pet owners were characterised by misunderstandings and misconceptions around antibiotics by pet owners, and a lack of clarity about the positions and intentions of the other party. Vets and pet owners had differing perceptions of where pressure to prescribe antibiotics inappropriately originated. Vets perceived it was mostly pet owners who pushed for inappropriate antibiotics, whereas pet owners reported they felt it was vets that overprescribed. Low levels of understanding of AMR in general were apparent amongst pet owners and understandings with regard to AMR in pets specifically were almost non-existent in the sample. Conclusions: Improved use of antibiotics could be assisted by educating the pet owning public and by guideline development for companion animal vets, concurrent development of mandatory legislation, increased consultation time to facilitate better communication, development of vet training on antimicrobial therapy and stewardship led interactions with pet owners, and increased levels of knowledge of pet-related AMR amongst pet owners

Characterizing the Catalytic Action of μ-Calpain on Myofibrillar Protein Structure

Solving the problem of inconsistent meat tenderness is a top priority of the meat industry. This requires a greater understanding of the processes that affect meat tenderness and the adoption of such information by the meat industry. It is essential that we understand the mechanism of meat tenderisation of which, the calpain protease system is believed to play a central role. This thesis focuses on three aspects; characterisation of calpain activity, the effect of porcine μ-calpain on myofibril degradation and the effect of μ-calpain on specific proteins desmin and troponin-T. To study the effect of calpain activity, fluorogenic assays were used to determine: μ-calpain concentration for optimal peptide cleavage; calcium requirements and the effect of chelating substances on the activity of μ-calpain. In addition, the affinity of μ-calpain for substrates CalS-I and CalS-III were assessed. The effect of μ-calpain on myofibril degradation was evaluated through the use of myofibrillar fragmentation index and density marker beads. Myofibrils were digested at three different temperatures for varying time periods. Conflicting results were displayed and it was concluded that these methods are not accurate, thus further research should be conducted to ensure inconsistencies are eliminated. Specific proteins desmin and troponin-T have previously been shown to exhibit degradation in the presence of calcium and μ-calpain. SDS-polyacrylamide electrophoresis, western blotting and densitometry measurements were utilized to investigate this effect. It was concluded that μ-calpain plays a significant role in the post mortem proteolysis of myofibrillar protein. This thesis provides information and strives to give a better understanding of the proteolytic changes that occur within muscle. Understanding how these mechanisms affect meat on a cellular level, can help to control the influence they inflict on meat quality

Identifying and detecting facial expressions of emotion in peripheral vision

Facial expressions of emotion are signals of high biological value. Whilst recognition of facial expressions has been much studied in central vision, the ability to perceive these signals in peripheral vision has only seen limited research to date, despite the potential adaptive advantages of such perception. In the present experiment, we investigate facial expression recognition and detection performance for each of the basic emotions (plus neutral) at up to 30 degrees of eccentricity. We demonstrate, as expected, a decrease in recognition and detection performance with increasing eccentricity, with happiness and surprised being the best recognized expressions in peripheral vision. In detection however, while happiness and surprised are still well detected, fear is also a well detected expression. We show that fear is a better detected than recognized expression. Our results demonstrate that task constraints shape the perception of expression in peripheral vision and provide novel evidence that detection and recognition rely on partially separate underlying mechanisms, with the latter more dependent on the higher spatial frequency content of the face stimulus