The effect of temporally variable environmental stimuli and group size on emergence behavior

How animals trade-off food availability and predation threats is a strong determinant of animal activity and behavior; however, the majority of work on this topic has been on individual animals, despite the modulating effect the presence of conspecifics can have on both foraging and predation risk. Although these environmental factors (food and predation threat) vary spatially within habitats, they also vary temporally, and in marine habitats, this can be determined by not only the diel cycle but also the tidal cycle. Humbug damselfish, Dascyllus aruanus, live in small groups of unrelated individuals within and around branching coral heads, which they collectively withdraw into to escape a predation threat. In this study, we measured the proportion of individuals in the colony that were outside the coral head before and after they were scared by a fright stimulus and compared the responses at high tide (HT) and low tide (LT). We found that a greater proportion of the shoal emerged after the fright stimulus at HT and in larger groups than at LT or in smaller groups. We also quantified the pattern of emergence over time and discovered the rate of emergence was faster in larger shoals as time progressed. We show that shoals of fish change their behavioral response to a predation threat in accordance with the tide, exemplifying how temporally variable environmental factors can shape group movement decisions

Initiation and spread of escape waves within animal groups

The exceptional reactivity of animal collectives to predatory attacks is thought to be due to rapid, but local, transfer of information between group members. These groups turn together in unison and produce escape waves. However, it is not clear how escape waves are created from local interactions, nor is it understood how these patterns are shaped by natural selection. By startling schools of fish with a simulated attack in an experimental arena, we demonstrate that changes in the direction and speed by a small percentage of individuals that detect the danger initiate an escape wave. This escape wave consists of a densely packed band of individuals that causes other school members to change direction. In the majority of cases this wave passes through the entire group. We use a simulation model to demonstrate that this mechanism can, through local interactions alone, produce arbitrarily large escape waves. In the model, when we set the group density to that seen in real fish schools, we find that the risk to the members at the edge of the group is roughly equal to the risk of those within the group. Our experiments and modelling results provide a plausible explanation for how escape waves propagate in Nature without centralised control

Cultural Resources Investigations of the Concho River Veribest Pipeline Replacement Project, San Angelo, Tom Green County, Texas

Raba Kistner Environmental, Inc. (RKEI), was contracted by Kleinfelder (CLIENT), on behalf of Valley Proteins, Inc., to perform cultural resources investigations for a pipeline rehabilitation and replacement project east of San Angelo in Tom Green County, Texas. The pipeline targeted for replacement is located within the channel of the Concho River, approximately 18 feet below the current banks. Archaeological investigations of this lower terrace focused on areas that may be impacted by the project, which includes laydown and equipment staging areas, as well as ingress and egress areas. Ashley E. Jones acted as Principal Investigator and Rhiana D. Ward served as Project Archaeologist. Rhiana D. Ward and Chris Matthews completed field investigations, which resulted in negative findings. All work was conducted under Texas Antiquities Committee Permit No. 8286. Although the pipeline is controlled by a privately-owned wastewater company, the project is located within and adjacent to lands owned by the City of San Angelo, a political subdivision of the state. As such, the project was subject to review under the jurisdiction of the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191). Furthermore, because the proposed project will directly impact the Concho River, compliance with Section 106 of the National Historic Preservation Act (54 United States Code 306108) and its implementing regulations (36 Code of Federal Regulations 800) will be required. A preliminary review conducted by the Texas Historical Commission (THC) and the U. S. Army Corp of Engineers-Fort Worth Division (USACE-FW) determined that archaeological investigations were required for the project due to its proximity to the Concho River, as well as its location within the boundaries of known archaeological site 41TG307. Site 41TG307 is designated as eligible for listing as a National Register of Historic Places (NRHP) property and was designated as a State Antiquities Landmark (SAL) in 1996. Archaeological investigations for the San Angelo Veribest Pipeline Replacement Project were conducted on January 24-25, 2018. Investigations consisted of an intensive pedestrian survey augmented with shovel testing of the 1.26-acre Area of Potential Effects (APE). Twelve shovel tests (STs) were excavated, with eight on the western side of the Concho River and four on the eastern side. Excavations encountered compact to very hard silty clay soils with modern refuse identified as deep as 50 centimeters below surface (cmbs) (ST 5 and ST 10). STs were excavated to a depth of 60 cmbs, except in locations where bedrock was shallowly buried beneath the soil. Compact soils and the presence of modern refuse indicated that the APE has been impacted, likely from the construction of Farm to Market 380 and the existing pipeline right-of-way. Additional disturbances documented include multiple sewer manholes near the western APE terminus, and an underground electric cable to the north of the APE. Approximately 0.27-acres of the western APE is located within the site boundaries of 41TG307. Site 41TG307 is a prehistoric open campsite recorded in 1991 atop an upper terrace of the Concho River. During a revisit in 1996, the site tested positive for multiple occupational components that date as early as the Early Archaic (5170-8210 B.C.). The artifact assemblage consists of burned rock, mussel shell fragments, lithic chert flakes at ground surface, and one possible rock-lined hearth feature. Site 41TG307 was designated as eligible for listing as a NRHP property and listed as an SAL in 1996 (THC 2018). Investigations conducted a total of five shovel tests (ST 1-5) within the known site boundaries of 41TG307, none of which identified any evidence of cultural materials or features. The portion of the site within the APE has been impacted from road and utility construction, evidenced by compact soils and the presents of modern materials (two aluminum pull tabs) at 20 to 40 cmbs within ST 5. Given this conclusion, RKEI does not recommend further archaeological investigations for the documented site located within the boundaries of the APE. Furthermore, no further work is recommended for the remaining APE. However, should changes be made to the project area, it is recommended that additional testing be conducted to determine the extent and significance of cultural deposits beyond the currently defined boundaries. Furthermore, because site 41TG307 is designated as eligible for listing as a NRHP property and is listed as an SAL, avoidance measures are recommended to prevent impacts of any cultural deposits that might not have been identified during investigations. The regulating agencies have required avoidance measures of the site and request the use of timber mats or other protective materials to prevent ground disturbance within the laydown area within the site boundary

Chapter 10 Telepractice in adult speech-language pathology during COVID-19

This collection is the first of its kind to examine the impact of the COVID-19 pandemic on the caseloads and clinical practice of speech-language pathologists. The volume synthesises existing data on the wide-ranging effects of COVID-19 on the communication, swallowing, and language skills of individuals with COVID infection. Featuring perspectives of scholars and practitioners from around the globe, the book examines the ways in which clinicians have had to modify their working practices to prioritise patient and clinician safety, including the significant increase in the use of telepractice during the pandemic. The volume also reflects on changes in training and education which have seen educators in the field redesign their clinical practicum in order to best prepare students for professional practice in an age of COVID-19 and beyond, as the field continues to grapple with the long-term effects of the pandemic. Offering a holistic treatment of the impact of COVID-19 on the work of speech-language pathologists, this book will be of interest to students, researchers, and clinicians working in the discipline

Escape path complexity and its context dependency in Pacific blue-eyes (Pseudomugil signifer)

The escape trajectories animals take following a predatory attack appear to show high degrees of apparent 'randomness' - a property that has been described as 'protean behaviour'. Here we present a method of quantifying the escape trajectories of individual animals using a path complexity approach. When fish (Pseudomugil signifer) were attacked either on their own or in groups, we find that an individual's path rapidly increases in entropy (our measure of complexity) following the attack. For individuals on their own, this entropy remains elevated (indicating a more random path) for a sustained period (10 seconds) after the attack, whilst it falls more quickly for individuals in groups. The entropy of the path is context dependent. When attacks towards single fish come from greater distances, a fish's path shows less complexity compared to attacks that come from short range. This context dependency effect did not exist, however, when individuals were in groups. Nor did the path complexity of individuals in groups depend on a fish's local density of neighbours. We separate out the components of speed and direction changes to determine which of these components contributes to the overall increase in path complexity following an attack. We found that both speed and direction measures contribute similarly to an individual's path's complexity in absolute terms. Our work highlights the adaptive behavioural tactics that animals use to avoid predators and also provides a novel method for quantifying the escape trajectories of animals.Comment: 9 page

Echoes in a Changing Urban Landscape: Memories and Place Identity in Durham, North Carolina

As former manufacturing cities attempt to participate in a modern economy no longer dependent upon manufacturing, aging infrastructure like factory warehouses become a potential asset. Rather than demolishing historic buildings, some cities are taking advantage of tax incentives and a public shift toward hip urban spaces, and remaking their city to fit a Creative Class culture. The process of remaking place incorporates the historic legacy of the place, the collective identity of its residents, and the contemporary ideal of a creative urban space. Much of the literature discussing place remaking or the rise of the Creative Class city focuses upon the recent transformation of demographics, culture, and economy. Often overlooked is the historic context and the role of the place's collective identity. Demonstrated here are the benefits of incorporating historic context. Also demonstrated are the important role played by residents' collective identity and how this identity is an intimate contributor to the landscape. The renovation of the historic landscape is efficient for cities and it is an attraction for the Creative Class, but it is also a critical period for people who are attached to historic sites. Through the use of oral histories, I am able to examine the complex nature of these relationships, discovering intricacies in the process of place remaking that are otherwise difficult to determine. GIS mapping technology is used to further investigate historic trends and their role in current identity making. Three major points regarding collective identity and place remaking are uncovered. First, the oral histories reveal that the formation of a collective identity connected to a particular place is not dependent upon a shared, identical experience. Second, a collective understanding about the quality of a place can be generated based upon the unique circumstances of one group. The creation of a shared place identity is not only dependent upon the agents involved in the place making, but also the bystanders (or witnesses) to such efforts. Finally, when the integrity of place is honored and sites retain meaning, the function of the place can be fluid. Place is not static.Doctor of Philosoph

The hygiene hypothesis and childhood asthma in Orange County, North Carolina

This thesis examines childhood asthma in Orange County, North Carolina and its relationship to the Hygiene Hypothesis. The Hygiene Hypothesis challenges traditionally held views on hygiene and asserts that decreased exposures to microbes during an infant’s first year of life results in the poor development of the immune system. According to this hypothesis, the lack of development in the immune system is at least partially responsible for the increasing number of autoimmune disorders, asthma being one of them. In addition to the cross-sectional analysis, spatial analysis is used to determine spatial patterning or clustering of childhood asthma cases in the county. A cross-sectional study was conducted including 427 households (1000 children). First and fourth grade households were surveyed via the Orange County School System. Geographic information was voluntarily collected on each household that participated. The results of the survey demonstrate that the primary factors impacting childhood asthma in Orange County are genetics, premature birth, daycare attendance, and urban/suburban living. Spatial analysis reveals areas of high prevalence in the county but clusters of questionable significance

In Society\u27s Shadow: Identifying Structural Violence in MUNA, a Burial Community from Late Intermediate Period (1100 - 1470 CE) Pachacamac, Peru.

Structural violence (SV) highlights how social structures harm communities via inequities in health, risk of trauma, and post-mortem treatment, however its applicability outside of Euroamerican capitalist contexts is unclear. Fifty-nine individuals from the MUNA cemetery (Pachacamac, Perú) from the Late Intermediate to Late Horizon Periods (1100-1532 CE) were analysed for evidence of SV. Nonspecific stress markers, osteoarthritis, pathological dental conditions, and physical trauma were recorded and compared as they related to age, sex and/or status and then contextualised using the Spanish Chronicles, ethnographic, and archaeological research. Inequities in resource or labour distribution but not amount to SV, but SV did operate through physical trauma; two nonadults were victims of human sacrifice and tinku. Analytically, SV is useful in non-Euromerican contexts, but its effectiveness will be negatively impacted by the amount and type of contextual evidence available, and social complexity will determine where SV will develop

Engineering of decellularised porcine bladder patches

For patients with end-stage bladder disease for which other treatment options have failed, the patient is treated surgically with either urinary diversion or bladder augmentation. Enterocystoplasty is the most common of these options, and it involves augmenting the bladder using a section of the patient's own intestine. However, there are several problems associated with the use of intestine for augmenting the bladder, and therefore an alternative augmentation material may be of benefit to patients. Numerous approaches have been used to develop tissue-engineered scaffolds capable of successfully augmenting bladders. Some of these approaches have involved the use of acellular tissue-derived materials, whereby the tissues are decellularised in order to remove immunogenic material and therefore prevent an immune reaction when transplanted allogeneically or xenogeneically. Decellularisation protocols typically involve a variety of chemical and physical processes which remove cells and other immunogenic material from the tissues. A protocol was previously developed to decellularise full-thickness porcine bladders. This material may have utility in bladder augmentation. The process involved distending the bladders with, and placing them in, a series of solutions. It was demonstrated that distending the whole organs was a necessary step in the decellularisation process. It was thought that this procedure applied biaxial strain to the wall of the tissue and reduced its thickness sufficiently for the solutions to penetrate the entire wall of the tissue. However, the method of distending whole bladders was not compatible with a scalable manufacturing process, and therefore the biomaterial was not able to be developed further. The overall aim of this project was to develop a novel method of manipulating bladder tissue which would enable bladder tissue to be decellularised in a way which would be compatible with a commercial manufacturing process. The original bladder decellularisation process used 500 ml of solutions to distend bladders. Preliminary experiments demonstrated that this volume was not always adequate to decellularise larger bladders. Filling experiments were performed to find relationships between bladder size and bladder capacity. A relationship between bladder capacity and bladder width*length was found to have a high correlation. Bladders were decellularised when filled to capacities calculated using the relationship. No signs of cellular material were observed in histological sections of these bladders, and DNA quantification indicated a removal of more than 99% of the DNA relative to native tissue. In order to determine the state of mechanical deformation of bladders during decellularisation, markers were placed on the surface of twelve bladders which were immersed in isotonic solution and slowly filled. Images taken of the bladders and markers during filling were used to calculate the strain of the tissues during the tests. The previously found relationships for bladder capacity were used to calculate the capacity of these bladders. The stress, strain and thickness of the bladders were calculated at the point the bladders were filled to their respective capacities. These strains were invariant with bladder capacity, and were equal to 2.0 and 1.4 in the circumferential and longitudinal directions respectively. Applying these strains to three bladders during decellularisation appeared to result in a complete removal of cellular material. It was thought that applying the required strains to bladder tissue deformed in a flat sheet configuration would be compatible with a manufacturing process. In order to apply biaxial strain to this highly compliant material, it was recognised that it would be appropriate to deform it using discrete points, placed along the edges of the tissue. The stretching of flat sheets of bladder using this method was modelled using finite element modelling to find an optimal stretching regime. The models demonstrated that deforming the tissue using five discrete points along each edge of the material would be adequate to ensure that the required strains would be applied to the tissue for decellularisation to occur. So that flat sheets of bladder could be decellularised, a piece of equipment was designed to hold pieces of bladder in the state of deformation which was previously modelled. The equipment took the form of a 3D-printed frame. A procedure was developed to stretch bladder tissue onto the frame. To test the hypothesis that bladder tissue could be decellularised in a flat sheet configuration, six bladders were stretched onto the frames and subject to the decellularisation process. Histological sections taken from decellularised bladder samples demonstrated a complete removal of cellular material, and a DNA extraction and quantification assay demonstrated that 99% of the DNA had been removed relative to the native controls. Bladders decellularised using the original process were transported in transport medium and processed within 4 h of bladder collection. A manufacturing process would require the tissue to be stored before processing. It was also recognised that it may not be necessary to transport bladders---which are destined for decellularisation---in transport medium, which was developed in order to maintain viable urothelial cells. To test the effects of freezing and transportation without transport medium, bladders were collected from the abattoir, transported without transport medium and subject to either one (six bladders) or two (six bladders) freeze-thaw cycles. Twelve fresh bladders were transported with transport medium. Bladders were immersed in solution and mechanically tested by distension, and their stress--strain curves calculated. There was no statistical difference between the toe region modulus and the transition stress of fresh, once-frozen and twice frozen bladders. There was a small but significant increase in the linear region modulus and transition stress of fresh bladders compared to the once- and twice-frozen bladders. No significant differences were found between once-frozen and twice-frozen bladders. To determine the effect of this revised transportation regime on bladder decellularisation, six bladders were transported without transport medium, subject to two freeze-thaw cycles and subject to the decellularisation process. Samples taken from these bladders for histological analysis and DNA quantification exhibited a complete removal of cellular material. In conclusion, this study demonstrated that applying suitable strains to flat sheets of bladder tissue was a viable method of deforming bladder tissue in order for it to be decellularised. Freezing the tissue up to two times before decellularisation resulted in some small but significant changes to the mechanical properties of the tissue, but did not affect the efficacy of the decellularisation process. It therefore may now be feasible to commercially produce decellularised full-thickness porcine bladder tissue

Analysis of Mantle Heterogeneity through Array Observations of Multipathing and its Expansion to a Global Scale

Many mysteries remain about the inner workings of the Earth from what the origins of lower mantle structures to when did plate tectonics begin. Seismology provides observations of the Earth’s interior by analysing phenomena such as the reflections of waves or anomalous timings of waves arriving at the recording stations. Through analysis of these phenomena, information such as the morphology, location and velocity perturbation of mantle heterogeneity has been constrained. Information about the velocity gradients, how quickly the seismic velocity of material changes with distance, at the boundaries of mantle heterogeneities has not been analysed to the same extent and can aid our understanding of its thermal and chemical properties. When a wave interacts with a sufficiently strong velocity gradient, the wave moves at two different speeds over a short distance leading to multiple arrivals arriving at the recording station. This phenomenon, called multipathing, has been analysed through the waveform complexity it creates and has led to estimations of the velocity gradients at the boundaries of mantle heterogeneity. In addition to the waveform complexity, the multiple arrivals should arrive with different directions and horizontal speeds through diffraction of the wave by the velocity gradient. The direction and horizontal speeds have seldom been used to analyse multipathed arrivals and could give more information about the heterogeneities. In this thesis, I use array seismology methods to analyse multipathing and diffraction of the wavefield by measuring the direction and speeds of the arrivals and expand the analysis to a global scale. First, I analyse multipathing caused by the African Large Low-Velocity Province (LLVP), a continent-sized anomaly at the core-mantle boundary beneath Africa, and show multipathing is frequency dependent and can be caused by relatively weak velocity gradients. Then, I develop a method to automate the identification of multipathing with array methods using cluster analysis which also provides uncertainty estimates of the measurements. Finally, this automated method is used to create a multi-regional map of SKS multipathing which motivates future studies analysing the conditions needed for multipathing and for comparison with other investigations into the Earth’s current state and evolution