137 research outputs found

    Determining the ages of sub-fossil cetacean remains, found in the Carse of Stirling, Scotland

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    During the 19th and early 20th centuries, sub-fossil cetacean remains were often discovered in the Firth of Forth, Central Scotland. These bones and skeletons of "Whales" were excavated from a recent, estuarine deposit (named "carse clay") and, within the biological and geological sciences, were not judged to be important. That palaeontological evidence is re-evaluated in this thesis. These cetacean remains have been preserved in an unusual marine environment and form an exceptional fossil assemblage, with almost no geological precedents. Why is it there? Whatever caused exceptional preservation in the Firth of Forth in the early Holocene (c. 9.5 – 2.5ka cal BP) can be best identified with chronological data. The ages of six sets of cetacean remains are determined in this thesis, by radiocarbon dating and stratigraphic inference. To reconstruct where a bone or skeleton had been found in the "carse" and then to identify any surviving elements in modern museum collections, archaic textual sources had to be thoroughly investigated. Radiocarbon dates from marine organisms require correction for "reservoir effects" and those applicable to mysticete cetaceans require careful consideration. The absolute dating evidence shows that no two "Whales" are the same age and that each died, and was then preserved, over the period 9.5 – 7.0ka cal BP. Therefore, a "disaster" (e.g. tsunami) or mass mortality is unlikely to have caused these remains to accumulate. A combination of physical processes and stable environmental conditions are more likely responsible, and might still permit exceptional preservation in the modern Firth of Forth. Actualistic experiment (observing if, and how, a cetacean carcass is preserved or dispersed on a modern tidal foreshore) would allow further insights into this cryptic palaeontological assemblage

    As in Life, So in Death? Identity, Gender, and Age in Neolithic Britain

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    Interpretive models for identity for the British Neolithic have been heavily focussed on group identities e.g., ancestor veneration, relational personhood, and house societies. While these theoretical frameworks for social organisation are undoubtedly important, they do not consider individual identity and the taxonomies which create it such as gender, age, and ethnicity. As identity taxonomies are deeply intertwined with social, cultural, and political factors then research into these could be crucial in improving understandings of British Neolithic society. One of the key reasons for this neglect of individual identities is the general nature of most British Neolithic funerary assemblages, i.e., commingled and disarticulated. This creates certain challenges when attempting to develop ideas regarding individual identity because specific individuals are difficult to recognise. The lack of attention to individual identities and their associated taxonomies for the period means that there is a large gap in knowledge in areas such as gender, age, status, kinship, etc. This blind spot for individual identity in the British Neolithic is what this thesis aims to rectify. The research focuses on the two key identity taxonomies of gender and age. To access elements of individual identity within the funerary record an innovative approach was developed for analysing it. The British Neolithic funerary record in its entirety was collated into a database and data from this was separated into two areas, lifeways, and demographic representation. This enabled comparative analyses to be conducted, which assessed divergences in the health, diet, mobility, and funerary rites between males, females, and different age groups. The results of this allowed new insights to be established regarding the lifeways and deathways of different demographic groups. This was then used to propose new interpretations regarding how biological sex and age may have affected individual identities during the British Neolithic

    Past, Present, and Future of Human Chemical Communication Research

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    Although chemical signaling is an essential mode of communication in most vertebrates, it has long been viewed as having negligible effects in humans. However, a growing body of evidence shows that the sense of smell affects human behavior in social contexts ranging from affiliation and parenting to disease avoidance and social threat. This article aims to (a) introduce research on human chemical communication in the historical context of the behavioral sciences; (b) provide a balanced overview of recent advances that describe individual differences in the emission of semiochemicals and the neural mechanisms underpinning their perception, that together demonstrate communicative function; and (c) propose directions for future research toward unraveling the molecular principles involved and understanding the variability in the generation, transmission, and reception of chemical signals in increasingly ecologically valid conditions. Achieving these goals will enable us to address some important societal challenges but are within reach only with the aid of genuinely interdisciplinary approaches

    Deconstructing Decapitation in Late Roman Gloucestershire and Oxfordshire, UK

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    The Roman conquest in Britain (AD 43) led to significant changes in indigenous settlements and agricultural systems, population diversity, social organization, economic activities, and funerary traditions. Archaeological investigations of burials from the first to fifth centuries AD in Britain have revealed a complex array of burial treatments and attitudes toward the dead, including decapitation burials, which are the most common form of differential burial represented in this period. Traditional interpretations of these burials have included infanticide, punitive execution, trophy taking, fear of the dead, and veneration practices. This project investigates a sample of decapitation burials from Gloucestershire and Oxfordshire dating to the Late Roman Period (3rd-5th c. AD) using quantitative and qualitative comparisons of skeletal remains, grave goods and other associated materials. The multi-scalar analysis of bioarchaeological and mortuary treatments demonstrated that no specific variable automatically distinguished a decapitated individual as an outlier or social deviant, reinforcing the need for the systematic application of contextual analysis, including osteological profiles, in our methodological assessments of lived experiences and the expression of identity in Late Romano-British society. This project contributes to the growing cross-disciplinary literature on how ancient populations utilized the body as an instrument in the performance of ritual violence, allowing a more nuanced interpretation of the culturally constructed body as a salient material object category in the Roman Iron Age

    The impact of genotype on the cellular architecture of dilated and arrhythmogenic cardiomyopathies

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    Herzinsuffizienz ist ein klinisches Syndrom, welches durch funktionelle und strukturelle Anomalien des Herzens verursacht wird, und ist weltweit die häufigste Todesursache. Die dilatative Kardiomyopathie, welche durch eine Vergrößerung der linken Herzkammer definiert ist, und die arrhythmogene Kardiomyopathie, welche im Gegensatz durch eine Dysfunktion der rechten Herzkammer definiert ist, sind eine der häufigsten Ursachen für Herzinsuffizienz. Trotz vieler Bemühungen die molekularen Veränderungen der Herzinsuffizienz zu charakterisieren, sind Zelltypzusammensetzung, Genexpressionsänderungen, und zelluläre Interaktionen unter pathologischen Bedingungen unbekannt. Um diese Fragen zu adressieren wurde ein Protokoll zur Isolation intakter Zellkerne entwickelt um Einzelkernsequenzierung im Herzen durchzuführen. Anschließend wurde mit dem entwickelten Protokoll die zelluläre Zusammensetzung des erwachsenen gesunden menschlichen Herzens charakterisiert. Hier war mein Fokus die Charakterisierung und Identifikation von Subformen von Fibroblasten, und deren Genexpressionsunterschiede in den linken und rechten Vorhöfen und Herzkammern. Basierend auf dieser Annotation wurden die Zelltypen und Subtypen von ungefähr 900.000 Zellkernen von 61 nicht-ischämischen Herzinsuffizienzpatienten mit unterschliedlichen pathogenen Varianten in DCM- und ACM-assoziierten Genen oder idiopathischen Erkrankungen charakterisiert und mit 18 gesunden Spenderherzen verglichen. Dieser Datensatz zeigte spezifische Unterschiede des linken und rechten Ventrikels mit differenziell regulierten Genen und Signalwegen, and Veränderungen in der Zusammensetzung der verschiedenen Zelltypen und Subtypen. Um genotyp-spezifische Antworten unabhängig zu bestätigen wurden Algorithmen des maschinellen Lernens angewendet, welche die zugehörige Genotyp-Untergruppe des Patienten mit hoher Genauigkeit vorhersagten. Zusammenfassend stellen die in dieser Arbeit veröffentlichten Daten das vorherrschende Dogma in Frage, dass Herzinsuffizienz auf einen gemeinsamen finalen Signalweg zurückzuführen ist.Heart failure is a clinical syndrom and leading cause of death worldwide, caused by functional and structural abnormalities of the heart. Dilated Cardiomyopathy, defined by a left ventricular enlargement, and arrhythmogenic cardiomyopathy, defined by a right ventricular dysfunction, are leading causes of heart failure. Despite previous efforts to characterise molecular changes in the failing heart, little is known on cell-type specific abundance and expression changes under pathological conditions, and how individual cell-types interact during heart failure and cardiac remodelling. To address this question, a protocol for the isolation of intact nuclei was firstly established to perform robust single-nucleus RNA sequencing in the heart. Next, the cell-type composition of the healthy adult human heart was characterised. Here my focus was on the fibroblast nieche by characterising fibroblast states, their composition and their atria- and ventricle-specific expression patterns. Cell type and state annotation was then used to characterize the transcriptome of roughly 900,000 nuclei from 61 failing, non-ischemic human hearts with distinct pathogenic variants in DCM and ACM genes or idiopathic disease and compared those to 18 healthy donor hearts. This dataset revealed distinct responses of the right and left ventricle with differently regulated genes and pathways, and compositional changes across cell types and states. To independently confirm genotype-specific responses, machine learning approaches were applied, predicting genotype subgroups with high accuracy. Taken together, the findings published in this thesis upend the prevalent dogma that heart failure results in a final common pathway

    Livestock-associated methicillin-resistant Staphylococcus aureus – studies on prevention of zoonotic transmission

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    Antimicrobial resistance is a major global concern driven especially by the misuse and overuse of antimicrobials both in humans and in animals. Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) are major causes of nosocomial infections. As these multiresistant bacteria are increasingly found in livestock, the role of livestock as a reservoir for human infections deserves attention. MRSA has been causing healthcare-related infections since the 1960s and community-associated infections since the 1990s. In 2004, new MRSA strains were detected in humans in Europe that were shown to be related to contact with pigs. These strains were later shown to belong to MRSA clonal complex 398 and are called livestock-associated MRSA (LA-MRSA). Prevalence of LA-MRSA in Europe is highest in pigs and veal calves, but it has also been found in other livestock, horses and companion animals. From asymptomatic, colonized animals, LA-MRSA may be transmitted especially to people working in close contact with livestock such as farmers and veterinarians, who in turn may transmit it further to healthcare facilities. ESBL-PE species are found in livestock, horses and companion animals. In Europe, prevalence is highest in pigs and broilers. Evidence on the zoonotic transmission of ESBL-PE is contradictory. People working on European pig and broiler farms have in some studies been shown to have higher ESBL-/AmpC-producing Escherichia coli prevalence rates than the general population. Infection prevention and control (IPC) practices including proper hand hygiene and the use of personal protective equipment are important to prevent the spread of multiresistant bacteria and other pathogens in healthcare settings. Studies on IPC practices in the veterinary setting have mostly concentrated on companion animal clinics. Ambulatory veterinarians work on several farms a day and transport their equipment and medications from farm to farm. Hand hygiene facilities are offered by the farm or stable owner. There are several studies on the eradication of LA-MRSA from pig farms. A less studied approach is the use of bacteriophages, viruses that infect bacteria, which have been studied as an alternative to antimicrobial agents. Studies on bacteriophage treatment against S. aureus infections in livestock are few and the results have been inconclusive. The aim of this study was to study 1) the carriage of multiresistant zoonotic bacteria in veterinarians in Finland, 2) LA-MRSA colonization and genomic diversity in Finnish pigs, 3) the practices of ambulatory livestock and equine veterinarians to prevent zoonotic transmission, and 4) bacteriophage treatment as a possible way to eradicate LA-MRSA from colonized pigs. MRSA and ESBL-PE prevalence was studied in veterinarians in Finland using both phenotypic and genotypic methods to characterize the isolates. A questionnaire was used to collect important background information on risk factors. To study the adherence of ambulatory livestock and/or equine veterinarians to IPC measures, the replies to the questionnaire of a subset of the respondents were analysed using statistical methods. Quantity and colonization patterns of LA-MRSA in Finnish pigs were studied on two farms – farm 1 and farm 2 (10 pigs per farm) – and in a controlled facility (9 pigs). The strains were further compared with sequences from Finnish Food Authority surveillance and infection samples using core genome multilocus sequence typing (cgMLST). The suitability of bacteriophages for the eradication of LA-MRSA from healthy carrier pigs was investigated in an open, controlled study. A cocktail containing three Staphylococcus bacteriophages was administered to the study group pigs (n=10) and a placebo solution to the control group pigs (n=9) three times. Phage and MRSA levels were observed for 22 days. In addition, phage antibodies in pig sera were monitored. Prevalence of LA-MRSA in veterinarians in Finland was 0.3% (1/320) and the strain found belonged to spa type t011 and multilocus sequence type (ST)398. Virulence genes and resistance genes were typical for LA-MRSA strains found in Finnish pigs. ESBL-producing E. coli were carried by 3.0% of veterinarians (9/297) and one of the strains was also an AmpC producer. Several STs, blaESBL/AmpC genes and plasmid types were found, with ST131 being the most prevalent ST. Travelling and use of antibiotics during the past 12 months was as common as among the average Finnish population. Ambulatory livestock and equine veterinarians (n=129) did not conform adequately to hygiene guidelines. Handwashing facilities were often adequate on farms according to 66.9% of the veterinarians but in stables only according to 21.4% (p<.001). When moving to the next farm or stable, 75.0% always washed their hands or used hand sanitizer in livestock practice but only 42.5% in equine practice (p<.001). In livestock practice a protective coat or overalls were always used by 91.6%, whereas in equine practice only by 27.7% (p<0.001). Altogether, 30.0% of the veterinarians reported cleaning their stethoscope less frequently than once a week. Quantities of LA-MRSA in pigs were low. On farm 1, MRSA was detected in all three samplings in the nares of all 10 pigs. On farm 2, MRSA was detected only in one sampling in three pigs. Quantities in the nasal samples were between 101 and 103 CFU/swab and in the skin samples between 101 and 102 CFU/swab. In the controlled facility, the nasal samples of all nine pigs were MRSA-positive at least once, and the trend was declining. Persistent low levels were detected on the skin. The strains and all sequences from the Finnish Food Authority but one clustered into one cluster in the cgMLST analysis. Bacteriophage treatment did not reduce LA-MRSA levels in healthy carrier pigs. Phages were detected in the samples the day following application. No side effects were observed in the pigs, and no bacteriophage antibodies were detected in the pig sera. In conclusion, prevalence of MRSA and ESBL-PE in veterinarians was low despite frequent animal contact. However, LA-MRSA was detected for the first time in a veterinarian in Finland, which, regarding the high prevalence in Finnish pigs, underlines the importance of protecting people working in close contact with pigs also in Finland. Ambulatory livestock and equine veterinarians’ adherence to IPC guidelines varied significantly between practice types. This may be partly explained by the poor availability of proper handwashing facilities in stables compared with farms as reported by the veterinarians. In addition, further education of both veterinarians and farm or stable owners is necessary. Low levels of LA-MRSA were observed in pigs on two farms and in the controlled facility. The declining trend in nasal samples in the clean environment of the controlled facility may indicate that air contamination could have been an important factor upholding the nasal carriage of LA-MRSA in pigs. The close relatedness of LA-MRSA t034 strains at the national level raises the question of which factors facilitate the spread of this successful clone. Possibly, due to the low levels of LA-MRSA in the pigs in the bacteriophage treatment trial, eradication of LA-MRSA using bacteriophages did not succeed. Further studies on the LA-MRSA t034 clone circulating in Finnish pigs as well as factors related to pig management that may explain the lower LA-MRSA prevalence in alternative farming systems may help to find ways to curb the spread of LA-MRSA in Finnish pigs.Useille antibiooteille vastustuskykyiset metisilliiniresistentti Staphylococcus aureus (MRSA) ja laajakirjoisia betalaktamaaseja (ESBL) tuottavat enterobakteerit ovat yleistyneet eläimillä ja ihmisillä. Viime vuosina niiden zoonoottinen leviäminen eläimistä ihmisiin on herättänyt kasvavaa huolta. Tuotantoeläimiin liitetty MRSA (LA-MRSA), jota Suomessa on todettu erityisesti sioilla, on uhka tuotantoeläinten kanssa työskenteleville ja voi heidän kauttaan levitä myös terveydenhuoltoon. Keski-Euroopassa sika- ja broileritiloilla työskentelevillä on todettu muuta väestöä korkeampi ESBL-bakteerien esiintyvyys. Väitöskirjan tavoitteena oli tutkia keinoja erityisesti LA-MRSA:n zoonoottisen leviämisen ehkäisemiseksi. Ensimmäisessä osatutkimuksessa selvitettiin MRSA- ja ESBL-bakteerien esiintyvyyttä eläinlääkäreillä. Esiintyvyys eläinlääkäreillä oli lukuisista eläinkontakteista huolimatta matala eikä poikennut muusta väestöstä. LA-MRSA:ta todettiin kuitenkin eläinlääkärillä Suomessa ensimmäistä kertaa. Tutkimuksen perusteella on tärkeää suojella sikojen parissa työskenteleviä tartunnalta. Talleilla ja maatiloilla eläimiä hoitavien eläinlääkärien hygieniakäytäntöjä selvittäneessä kyselytutkimuksessa todettiin, ettei erityisesti talleilla ollut riittäviä käsienpesumahdollisuuksia. Eläinlääkärit myös noudattivat hygieniasuosituksia talleilla huonommin kuin tiloilla. Havainnon perusteella eläinten omistajien ja eläinlääkärien infektiontorjunnan opastus on ensiarvoisen tärkeää zoonoottisten taudinaiheuttajien leviämisen torjunnassa. LA-MRSA-kantajuutta kartoittaneessa tutkimuksessa bakteeripitoisuudet sekä sikojen sieraimissa että iholla olivat hyvin matalia. Sioista eristettyjä kantoja verrattiin geneettisesti toisiinsa sekä Ruokaviraston sioilta seurantatutkimuksissa ja infektionäytteistä eristämiin kantoihin vuosilta 2008–2017. Tulosten perusteella suomalaisissa sioissa on kiertänyt useiden vuosien ajan sama LA-MRSA-klooni, jonka menestyksen syytä olisi tärkeä selvittää tarkemmin. LA-MRSA:n esiintyvyyttä yritettiin kokeellisesti vähentää sioissa bakteriofagien eli faagien avulla. Faagit ovat luonnossa esiintyviä bakteereja infektoivia viruksia, jotka lisääntymiskiertonsa päätteeksi tappavat bakteerin. Kokeessa faagit eivät vähentäneet LA-MRSA:n pitoisuuksia tai esiintyvyyttä tutkituissa sioissa, mikä voi selittyä oireettoman kantajuuden alhaisilla bakteeripitoisuuksilla. Tutkimuksessa saatiin kuitenkin tärkeää tietoa myöhempiä faagitutkimuksia varten. Väitöskirja tuo uutta tietoa LA-MRSA:sta ja sen torjunnasta Suomessa. Eläinten kanssa työskentelevien valistus ja LA-MRSA-kantojen tarkempi tuntemus ovat tässä avainasemassa

    Coastal fishes of the western Indian Ocean

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    The primary purpose of this book is to provide a means of identifying the more than 3 200 species of coastal fishes known to occur in the Western Indian Ocean (WIO). Coastal fishes are those that inhabit waters generally less than ~200 m deep, the waters over continental and insular shelves, and upper continental slopes. The book also includes some oceanic species and species that live in deeper water, but are sometimes caught in trawls in less than 200 m, or that migrate into shallower waters at night to feed. The Western Indian Ocean (WIO), as treated in these volumes, is the area between Cape Point, South Africa, and 77°34' E, at Kanyakumari (formerly Cape Cormorin), the southernmost point of India, and to 40° S, just south of St Paul Island. Although considered as separate water bodies, the Red Sea and Persian/Arabian Gulf have been included. Some contributors have also chosen to include species from Sri Lanka. The region thus encompasses the entire east and southern coasts of Africa, Madagascar and the various island clusters of the Comoros, the Seychelles, the Maldive and Lakshadweep islands, the Chagos Archipelago and the islands and sea mounts of the Mascarene Plateau, to as far as 40° S, and thus some fishes from St Paul and Amsterdam Islands have been included. This large expanse, stretching from tropical waters of the northwestern Indian Ocean to the warm temperate waters of False Bay, South Africa, includes a number of poorly known biogeographic areas. A map of the entire Indian Ocean is placed on the inside front cover of each printed volume, with some areas in greater detail on the inside back cover. The book does not include distribution maps for species, but gives localities from which species are known, with emphasis on WIO localities; our understanding of distributions of many species is often incomplete. Fishes are the most abundant and diverse group of vertebrates and have colonised every aquatic habitat on Earth: the oceans, lakes, rivers and caves, from polar seas at –2 °C to hot, freshwater springs at 44 °C, and from tropical reefs and mangrove forests to the deepest ocean depths. Fishes are also the most poorly known group of vertebrates. In the 2006 edition of Joseph Nelson’s Fishes of the World the estimate of the number of species of extant fishes worldwide stood at about 23 000. This number is growing annually, and was thought to be about 33 460 species at the end of 2016 (www.fishwisepro.com). Between the years 2000 and 2015 an average of 150 new species of marine fishes were described each year – of which 10% of the total (156 species) were from the WIO. The WIO is home to about 15% of all the marine fish species in the world’s oceans. Another measure of the diversity of fishes of this area is its relatively high level of endemicity, particularly around southern Africa and in the Red Sea. About 13% of southern African marine fishes are endemic, most of these in only five families: Clinidae with about 44 endemic species, Gobiidae with 28, Sparidae with 28, Pentanchidae with 6, and Batrachoididae with 7 endemic species. In the Red Sea at least 170 of the more than 1100 species are endemic. The WIO region is also home to a large human population, representing a wide range of ethnic and cultural backgrounds. The area includes the countries of South Africa, Mozambique, Tanzania, Kenya, Somalia, Eritrea, Sudan, Egypt, Israel, Jordan, Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, Iran, Pakistan, India and Sri Lanka, as well as the many island nations and territories. Many of the people living in coastal areas are dependent on fish catches and other marine resources for both sustenance and often a livelihood, as highly diversified artisanal fisheries make up the bulk of the fishing effort in the region. And, as elsewhere in the world, many of the fish resources have been compromised by commercial interests (including those of other countries), often leaving fish stocks in a poor state. This book has a number of purposes, all of which coalesce around providing users with a better understanding of the area’s fishes and their environment. Accordingly, it includes a number of background chapters covering subjects as diverse as the oceanography of the region, and the history and evolution of the bony fishes. In recent years genetic analysis has proved to be a powerful tool for taxonomists. In many instances molecular results have caused taxonomists to rethink both the definitions of certain taxa and the interrelationships of taxa. In some instances, what were long considered cohesive (monophyletic) taxa were found to include groups of fishes that are in fact not closely related (paraphyletic), while in other instances taxa thought to be distinct were found not to be, meriting their merging with other existing taxa. At times, long-accepted family groups have been divided into two or more distinct families, or separate families have been combined into a single one. Where possible such changes in our understanding of the relationships of fishes are reflected in these volumes. Where some contributors have taken a more conservative approach by awaiting more research and not adopting these changes, alternative taxonomies are noted (see also the introductory chapter on Naming organisms and determining their relationships). For each species in the book, the literature pertinent to that species in the WIO is given: the original species description reference, synonyms for the region and other important taxonomic and biological references. For many commercially important species or fishes of interest to anglers there is additional information on life history, size and capture, and for some but not all species, their IUCN conservation status if Near Threatened, Vulnerable, Endangered or Critically Endangered (in the first instance, valid at the time of writing. See www.iucnredlist.org for current information. Note: we have not included the IUCN conservation status where species are of Least Concern or Data Deficient). Most species are illustrated with photographs, drawings or paintings. Colour photographs and paintings are provided on plates for each volume.1st Editio

    Treatise on Hearing: The Temporal Auditory Imaging Theory Inspired by Optics and Communication

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    A new theory of mammalian hearing is presented, which accounts for the auditory image in the midbrain (inferior colliculus) of objects in the acoustical environment of the listener. It is shown that the ear is a temporal imaging system that comprises three transformations of the envelope functions: cochlear group-delay dispersion, cochlear time lensing, and neural group-delay dispersion. These elements are analogous to the optical transformations in vision of diffraction between the object and the eye, spatial lensing by the lens, and second diffraction between the lens and the retina. Unlike the eye, it is established that the human auditory system is naturally defocused, so that coherent stimuli do not react to the defocus, whereas completely incoherent stimuli are impacted by it and may be blurred by design. It is argued that the auditory system can use this differential focusing to enhance or degrade the images of real-world acoustical objects that are partially coherent. The theory is founded on coherence and temporal imaging theories that were adopted from optics. In addition to the imaging transformations, the corresponding inverse-domain modulation transfer functions are derived and interpreted with consideration to the nonuniform neural sampling operation of the auditory nerve. These ideas are used to rigorously initiate the concepts of sharpness and blur in auditory imaging, auditory aberrations, and auditory depth of field. In parallel, ideas from communication theory are used to show that the organ of Corti functions as a multichannel phase-locked loop (PLL) that constitutes the point of entry for auditory phase locking and hence conserves the signal coherence. It provides an anchor for a dual coherent and noncoherent auditory detection in the auditory brain that culminates in auditory accommodation. Implications on hearing impairments are discussed as well.Comment: 603 pages, 131 figures, 13 tables, 1570 reference

    The Infrasonic Impact: Exploring the cognitive impact of frequencies below the hearing threshold during short term exposure

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    Infrasonic sound or sound below the generally accepted audible threshold is a persistent part of most modern environments and human beings have a near-constant exposure to it as it exists both naturally and from mechanical sources. While infrasonic sound frequencies are below the hearing threshold (20 to 20,000 Hz), studies show that they are still perceived by the human auditory system. Despite this evidence, studies determining the potential impact of infrasonic sound or the perception of the existence of infrasonic sound on cognition are scarce due to the challenges surrounding the delivery of infrasonic frequencies in a controlled environment such as replicating a non-audible sound, delivering this to participants and avoiding other overlap with other frequencies. There is rigorous discussion around what impact the placebo effect may have on infrasonic sound, with schools of thought vacillating between the placebo effect having no impact at all and it being the sole cause of any reported symptoms including changes to concentration abilities and diminished memory in subjects. As there remains no conclusive explanation for the relation between priming in the form of created expectation and the actual effect of infrasound, this leads to the question of whether infrasound may be able to affect cognitive functioning in any way. Determining the affect, and then studying the applications or mitigations needed to achieve a beneficial outcome to improve cognition by enhancing or inhibiting infrasonic sound are the focal point of this study. This project explores the influence of infrasound on cognition by testing reaction time to stimuli and working memory in the presence and absence of exposure to infrasonic frequencies, using an advanced technical setup alongside tools like the Simon test and the n-back test. This approach creates a system to deliver infrasonic sound discreetly (without participant knowledge in all instance, unless briefed) and study the impact on short-term exposure patterns. In contrast, most research to date has investigated the possible effects that long-term exposure to infrasound (spanning months to years) may have on sleep 4 patterns and biological functions, with mixed findings. A number of studies have attempted to detect any correlation or investigate the relationship between reported symptoms (irritability, trouble with concentration/attention, dizziness, anxiousness, extreme fatigue and other self reported health concerns) in those exposed to constant infrasound generated by wind turbines, with some arguing a relationship between this exposure and perceived negative effects (the validity of which remains uncertain) and others unable to find evidence of a clear link between sound and symptomatology. While exposure to infrasonic frequencies is a temperamental process due to the complexity of the technical set up needed and variation in exposure and delivery (and the reported effects are being debated), functional magnetic resonance imaging (fMRI) studies have been able to map the neural changes based on cerebral blood flow. Certain fMRI studies make note of brain stimulation on exposure to infrasonic sound, and are consistent with a potential effect on cognitive performance. This project aims to explore whether exposure to infrasonic sound can influence cognitive function using measures of accuracy, and reaction times as outcome measures in tests of reaction times and working memory intended to determine whether this could enhance or inhibit cognitive functioning. While long-term exposure could have a number of variables that may not be noticed, short term exposure limits any potential long lasting negative effects and allows us to take a closer look at immediate impact. This project additionally intends to further explore the impact of positive and negative expectation on individuals exposed to infrasound, by creating positive/negative impressions prior to exposure using media created for the purpose of creating expectation. The concepts of placebo and nocebo, or the impact of positive and negative expectation, are argued to be contributory to the real and imagined impacts of infrasonic sound. If infrasonic sound has a genuine impact on human cognitive performance, then the level to which this can be exploited or inhibited may have a proportional relationship with individual expectation of impact. 5 This research intends to further provide insight into the impact of infrasound on cognitive functioning and the relationship that awareness of infrasound (in the form of expectation) has on this outcome. The outcome of this study showed that accuracy when conducting cognitive tasks is not affected by the presence of infrasonic frequencies in a significant way. However, there was an observed negative impact on simple reaction times (time taken between the observation of a stimulus and the response to the stimulus as set out by the task) in the presence of infrasonic frequencies. This suggests an impact on cognition due to the presence of infrasonic frequencies in an environment requiring computer-based information processing tasks. This outcome has practical implications for drug free methodology for cognitive enhancement, potentially creating a context within which we can purposefully prevent deterioration of memory recall and reaction time using the controlled absence of infrasonic sound

    Experience-dependent reshaping of body processing: from perception to clinical implications

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    Starting from the moment we come into the world, we are compelled to pay large attention to the body and its representation, which can be considered as a set of cognitive structures that have the function of tracing and coding our state (de Vignemont, 2010). However, we cannot consider body aside from its image, which can determine the way we emotionally perceive ourselves and other people as well as the way we experience the world. With a brief look to the body, we can identify a persons’ identity, thus catching distinctive elements such as her age or gender; further, by means of body posture and movements we can understand the affective state of others and appropriately shape our social interaction and communication. Several socially significant cues can be detected and provided through the body, but this thesis principally aims to increase the knowledge about how we perceive gender from bodily features and shape. Specifically, I report on a series of behavioral studies designed to investigate the influence of the visual experience on the detection of gender dimension, considering the contribution of brain networks which may also have a role in the development of mental disorders related to body misperception (i.e. Eating Disorders; ED). In the first chapter, I provide evidence for the interdependence of morphologic and dynamic cues in shaping gender judgment. By manipulating various characteristics of virtual-human body stimuli, the experiment I carried out demonstrates the association between stillness and femininity rating, addressing the evolutionary meaning of sexual selection and the influence of cultural norms (D’Argenio et al., 2020). In the second chapter, I present a study that seeks to define the relative role of parvo- and magnocellular visual streams in the identification of both morphologic and dynamic cues of the body. For these experiments, I used the differential tuning of the two streams to low- (LSF) and high-spatial frequencies (HSF) and I tested how the processing of body gender and postures is affected by filtering images to keep only the LSF or HSF (D’Argenio et al., submitted). The third chapter is dedicated to a series of experiments aimed at understanding how gender perception can be biased by the previous exposure to specific body models. I utilized a visual adaptation paradigm to investigate the mechanisms that drives the observers’ perception to a masculinity or femininity judgement (D’Argenio et al., 2021) and manipulates the spatial frequency content of the bodies in order to account for the contribution of parvo- and magnocellular system in in this process. In conclusion, in the last two chapters, I briefly report the preliminary results emerging from two visual adaptation studies. The first one, which is described in the fourth chapter, explored the role of cortical connections in body gender adaptation by means of Transcranial Magnetic Stimulation (TMS), with the aim to investigate neural correlates of dysfunctional body perception. The second represents the intent to explain, at least partially, body misperception disorders by applying adaptation paradigms to ED clinical population. Results were discussed in the fifth chapter.Starting from the moment we come into the world, we are compelled to pay large attention to the body and its representation, which can be considered as a set of cognitive structures that have the function of tracing and coding our state (de Vignemont, 2010). However, we cannot consider body aside from its image, which can determine the way we emotionally perceive ourselves and other people as well as the way we experience the world. With a brief look to the body, we can identify a persons’ identity, thus catching distinctive elements such as her age or gender; further, by means of body posture and movements we can understand the affective state of others and appropriately shape our social interaction and communication. Several socially significant cues can be detected and provided through the body, but this thesis principally aims to increase the knowledge about how we perceive gender from bodily features and shape. Specifically, I report on a series of behavioral studies designed to investigate the influence of the visual experience on the detection of gender dimension, considering the contribution of brain networks which may also have a role in the development of mental disorders related to body misperception (i.e. Eating Disorders; ED). In the first chapter, I provide evidence for the interdependence of morphologic and dynamic cues in shaping gender judgment. By manipulating various characteristics of virtual-human body stimuli, the experiment I carried out demonstrates the association between stillness and femininity rating, addressing the evolutionary meaning of sexual selection and the influence of cultural norms (D’Argenio et al., 2020). In the second chapter, I present a study that seeks to define the relative role of parvo- and magnocellular visual streams in the identification of both morphologic and dynamic cues of the body. For these experiments, I used the differential tuning of the two streams to low- (LSF) and high-spatial frequencies (HSF) and I tested how the processing of body gender and postures is affected by filtering images to keep only the LSF or HSF (D’Argenio et al., submitted). The third chapter is dedicated to a series of experiments aimed at understanding how gender perception can be biased by the previous exposure to specific body models. I utilized a visual adaptation paradigm to investigate the mechanisms that drives the observers’ perception to a masculinity or femininity judgement (D’Argenio et al., 2021) and manipulates the spatial frequency content of the bodies in order to account for the contribution of parvo- and magnocellular system in in this process. In conclusion, in the last two chapters, I briefly report the preliminary results emerging from two visual adaptation studies. The first one, which is described in the fourth chapter, explored the role of cortical connections in body gender adaptation by means of Transcranial Magnetic Stimulation (TMS), with the aim to investigate neural correlates of dysfunctional body perception. The second represents the intent to explain, at least partially, body misperception disorders by applying adaptation paradigms to ED clinical population. Results were discussed in the fifth chapter
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