Long-Term Effects of Concussion on Motor Performance Across the Lifespan.

This dissertation aims to provide critical insight into the possible long-term effects of concussion on motor and cognitive performance, through a set of cross-sectional investigations. To date, the elite athlete population has garnered most of the research and public attention, while the largest athletic population, high school athletes, has been largely overlooked. The hypotheses state that individuals with a concussion history will have worse cognitive and motor performance and that this trend will be divergent with age. That is, the previously concussed individuals will exhibit worse performance, and will be divergently worse from the control group with age. With this in mind, the three investigations focus on cognitive and motor performance in three age groups (i.e. 20, 40, and 60 year olds), in those with and without an adolescent concussion history. The first investigation assessed cognition between concussion history and control groups, within age groups. Using a standard computer-based, clinical concussion assessment, processing speed, attention, learning, working memory accuracy and working memory speed were quantified for each concussion group by age. There were no differences between the concussion history and control groups, within age. The second investigation assessed gait spatio-temporal, kinematic, and toe clearance variables. Again, no significant concussion history group differences were observed in the multivariate assessment for the gait spatio-temporal, kinematic, and toe clearance variables. In addition, there appeared to be no pattern suggesting that a concussion history adversely affects gait, across age. The final investigation assessed skill acquisition, implicit learning, and the internal timing mechanism between concussion history and control groups, within age. Again, there was no consistent pattern to suggest an adverse relationship between concussion history and motor performance, across age. Considering this set of observations, there does not appear to be a long-term, negative relationship between adolescent concussion history and cognition or motor performance in this population.PhDKinesiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113411/1/dnmart_1.pd

The Measurement of Eye Movements in Mild Traumatic Brain Injury: A Structured Review of an Emerging Area

Mild traumatic brain injury (mTBI), or concussion, occurs following a direct or indirect force to the head that causes a change in brain function. Many neurological signs and symptoms of mTBI can be subtle and transient, and some can persist beyond the usual recovery timeframe, such as balance, cognitive or sensory disturbance that may pre-dispose to further injury in the future. There is currently no accepted definition or diagnostic criteria for mTBI and therefore no single assessment has been developed or accepted as being able to identify those with an mTBI. Eye-movement assessment may be useful, as specific eye-movements and their metrics can be attributed to specific brain regions or functions, and eye-movement involves a multitude of brain regions. Recently, research has focused on quantitative eye-movement assessments using eye-tracking technology for diagnosis and monitoring symptoms of an mTBI. However, the approaches taken to objectively measure eye-movements varies with respect to instrumentation, protocols and recognition of factors that may influence results, such as cognitive function or basic visual function. This review aimed to examine previous work that has measured eye-movements within those with mTBI to inform the development of robust or standardized testing protocols. Medline/PubMed, CINAHL, PsychInfo and Scopus databases were searched. Twenty-two articles met inclusion/exclusion criteria and were reviewed, which examined saccades, smooth pursuits, fixations and nystagmus in mTBI compared to controls. Current methodologies for data collection, analysis and interpretation from eye-tracking technology in individuals following an mTBI are discussed. In brief, a wide range of eye-movement instruments and outcome measures were reported, but validity and reliability of devices and metrics were insufficiently reported across studies. Interpretation of outcomes was complicated by poor study reporting of demographics, mTBI-related features (e.g., time since injury), and few studies considered the influence that cognitive or visual functions may have on eye-movements. The reviewed evidence suggests that eye-movements are impaired in mTBI, but future research is required to accurately and robustly establish findings. Standardization and reporting of eye-movement instruments, data collection procedures, processing algorithms and analysis methods are required. Recommendations also include comprehensive reporting of demographics, mTBI-related features, and confounding variables

Using object-based image analysis to detect laughing gull nests

Remote sensing has long been used to study wildlife; however, manual methods of detecting wildlife in aerial imagery are often time-consuming and prone to human error, and newer computer vision techniques have not yet been extensively applied to wildlife surveys. We used the object-based image analysis (OBIA) software eCognition to detect laughing gull (Leucophaeus atricilla) nests in Jamaica Bay as part of an ongoing monitoring effort at the John F. Kennedy International Airport. Our technique uses a combination of high resolution 4-band aerial imagery captured via manned aircraft with a multispectral UltraCam Falcon M2 camera, LiDAR point cloud data, and land cover data derived from a bathymetric LiDAR point cloud to classify and extract laughing gull nests. Our ruleset uses the site (topographic position of nest objects), tone (spectral characteristic of nest objects), shape, size, and association (nearby objects commonly found with the objects of interest that help identify them) elements of image interpretation, as well as NDVI and a sublevel object examination to classify and extract nests. The ruleset achieves a producer’s accuracy of 98% as well as a user’s accuracy of 65% and a kappa of 0.696, indicating that it extracts a majority of the nests in the imagery while reducing errors of commission to only 35% of the final results. The remaining errors of commission are difficult for the software to differentiate without also impacting the number of nests successfully extracted and are best addressed by a manual verification of output results as part of a semi-automated workflow in which the OBIA is used to complete the initial search of the imagery and the results are then systematically verified by the user to remove errors. This eliminates the need to manually search entire sets of imagery for nests, resulting in a much more efficient and less error prone methodology than previous unassisted image interpretation techniques. Because of the extensibility of OBIA software and the increasing availability of imagery due to small unmanned aircraft systems (sUAS), our methodology and its benefits have great potential for adaptation to other species surveyed using aerial imagery to enhance wildlife population monitoring

Paisagens nas ruínas do desenvolvimento metropolitano : narrativas cartográficas entre os municípios de Triunfo (RS) e Montenegro (RS)

Esta pesquisa faz parte de uma experiência cartográfica vivida enquanto habitante e pesquisador, cujo objetivo foi apreender e refletir sobre as paisagens às margens da BR- 386, entre os municípios de Triunfo e Montenegro, a oeste da Região Metropolitana de Porto Alegre/RS (RMPA). Nesse contexto de estudo, próximo ao complexo industrial do III Pólo Petroquímico, são desenvolvidas atividades de comércio, serviço, extrativismo, silvicultura, indústria, logísticas, monoculturas, entre outras, que dão a ver as complexidades de um intenso processo de urbanização da paisagem metropolitana engendrado nas últimas décadas. Através da abordagem teórico-metodológica da narrativa, a paisagem é aqui entendida a partir de uma perspectiva contemporânea, onde as paisagens são um acontecer de vários aconteceres, visíveis e invisíveis, entrelaçados ao longo do tempo e do espaço, em meio a práticas cotidianas e histórias das e dos habitantes. A cartografia nesta pesquisa é entendida tanto como cartografia da ação social quanto como cartografia sentimental. Sendo assim, não se trata de representar uma paisagem emoldurada, mas de dar atenção aos materiais e às forças que se movem em meio à paisagem. Seguindo os rastros de dois grandes projetos de escala metropolitana e regional, a ampliação da BR-386 e o Aterro Industrial na localidade de Pesqueiro, produzo dois ensaios cartográficos inspirados pelas operações metodológicas da montagem, cuja disposição de fragmentos de um acervo narrativo em movimento faz emergir sintomas de uma paisagem arruinada. É através desses sintomas que busco emaranhar as estratégias dos empreendimentos, suas arenas políticas, as operações que mobilizam e seus impactos, ao mesmo tempo em que disponho as experiências cotidianas de vizinhas e vizinhos que narram sobre modos de resolver a vida que escapam e/ou interpelam as lógicas desse desenvolvimento metropolitano. Chego, por fim, à "paisagem brutalista" e à "paisagem de sacrifício", duas pistas que deslocam a paisagem da sua tradicional objetificação e convocam seu entendimento enquanto expressão de uma permanente disputa de forças, a ser incorporada nos estudos urbanos e regionais.This research is part of a cartographic experience lived as an inhabitant and researcher, whose objective was to apprehend and reflect on the landscapes on the roadsides of the BR-386 highway, between the municipalities of Triunfo and Montenegro, west of the Metropolitan Region of Porto Alegre/RS (RMPA). In this context of study, adjacent to the industrial structure of the III Petrochemical Complex, practices such as commerce, service, extractivism, forestry, industry, logistics and monoculture activities are developed, which reveal the complexities of an intense process of urbanization of the metropolitan landscape engendered along recent decades. Through a theoretical-methodological approach of the narrative, the landscape is understood here from a contemporary perspective, where landscapes are a happening of several happenings, visible and invisible, entangled over time and space, in the midst of everyday practices and stories of the inhabitants. The cartography in this research is understood both as a cartography of social action and as a sentimental cartography. Therefore, it is not a question of representing a framed, static landscape, but of paying attention to the materials and forces that act throughout a landscape. Following in the trails of two projects on a metropolitan and regional scale, the expansion of the BR-386 highway and the Industrial Landfill in the locality of Pesqueiro, I produce two cartographic essays inspired by the methodological operations of montage, whose arrangement of fragments of an ongoing narrative collection brings out symptoms of a ruined landscape. It is through these symptoms that I seek to entangle the strategies of the enterprises, their political stages, the operations they mobilize and their impacts, at the same time that I present the daily experiences of neighbors who tell stories about ways of solving life that escape and/or question the logics of this metropolitan development. Finally, I arrive at "brutalist landscape" and "sacrifice landscape", two landscape sayings that displace landscape from its traditional objectification and summon its understanding as an expression of a permanent dispute of forces, to be embodied in urban and regional studies

VARIATIONS IN PITCHING PERFORMANCE DURING A MAJOR LEAGUE BASEBALL GAME: WHAT CAN WE LEARN FROM BALL TRACKING DATA?

The aim of this study was to identify changes in pitching characteristics during nine innings of professional (MLB) baseball. Ball tracking data were obtained for 1,514,304 pitches thrown by 129 pitchers during the 2008–2014 MLB seasons and compared across the nine innings using linear mixed model analyses. Earlier innings contained significantly more hard (i.e., fast-type) pitches. A significant decrease in pitch speed and release height emerged before the sixth inning. These data revealed that aspects of a starting pitcher’s performance significantly change as early as the second or third inning of an MLB game, although these do not influence his effectiveness. Coaches may use these data to inform their decision to relieve a starting pitcher and/or direct in-game strategies to exploit trends in pitcher performance

Cortical activity during walking and balance tasks in older adults and in people with Parkinson’s disease: a structured review

An emerging body of literature has examined cortical activity during walking and balance tasks in older adults and in people with Parkinson’s disease, specifically using functional near infrared spectroscopy (fNIRS) or electroencephalography (EEG). This review provides an overview of this developing area, and examines the disease-specific mechanisms underlying walking or balance deficits. Medline, PubMed, PsychInfo and Scopus databases were searched. Articles that described cortical activity during walking and balance tasks in older adults and in those with PD were screened by the reviewers. Thirty-seven full-text articles were included for review, following an initial yield of 566 studies. This review summarizes study findings, where increased cortical activity appears to be required for older adults and further for participants with PD to perform walking and balance tasks, but specific activation patterns vary with the demands of the particular task. Studies attributed cortical activation to compensatory mechanisms for underlying age- or PD-related deficits in automatic movement control. However, a lack of standardization within the reviewed studies was evident from the wide range of study protocols, instruments, regions of interest, outcomes and interpretation of outcomes that were reported. Unstandardized data collection, processing and reporting limited the clinical relevance and interpretation of study findings. Future work to standardize approaches to the measurement of cortical activity during walking and balance tasks in older adults and people with PD with fNIRS and EEG systems is needed, which will allow direct comparison of results and ensure robust data collection/reporting. Based on the reviewed articles we provide clinical and future research recommendations

Simultaneous control of DNA and RNA processing efficiency using a nucleic acid calibration set.

PCR-based detection techniques enables reliable and sensitive nucleic acid target detection. However, quantitative determination methods often fail to control for the efficiency of nucleic acid extraction, reverse transcription, and PCR amplification. This problem is even more prominent when working with clinical samples due to target sequence loss during nucleic acid processing or the co-purification of PCR inhibitors (1,2). Handling processes are often assumed to approach 100% efficiency in the laboratory, even if practical experience shows that this efficiency can be much lower. This inability to ensure accuracy can lead to significant error in uncalibrated DNA sample quantitation. The additional need for reverse transcription of RNA may further increase the quantitative error rate, as yet another enzymatic process is involved. Nucleic acid controls have been developed based upon known sequences to calibrate either DNA or RNA handling; DNA calibrators have been used to control for the amplification of target sequences using realtime PCR methods (3–8), while RNA calibrators have been developed to test reverse transcription and amplification efficiencies (9–11). A nonpathogenic viral particle carrying a sequence for use as an external positive control of extraction and amplification has also been described (12). Unfortunately, most of the established processing controls are only suitable for limited applications (i.e., either DNA or RNA detection). Cross-contamination of biological samples or minute detection from natural sources reveals the need for completely synthetic sequences, with no homology to sequences in the nucleic acid databases. It is, therefore, beneficial to design an internal, synthetic calibration system that can control for both DNA and RNA processing steps in a single tube. This set includes both RNA and DNA targets with identical primer binding sites and, thus, primer binding efficiency, but easily distinguishable sequence characteristics, allowing for simultaneous detection, quantitation, and calibration of nucleic acid processing efficiency. A 150-bp randomly generated nucleic acid sequence was developed for use as a short control (SC). A GCrich 75-bp sequence was inserted in the middle of the 150-bp sequence to generate a 225-bp sequence, long control (LC). Besides size, the two sequences were designed to have easily distinguishable probe binding sites with a predicted product melting temperature difference of 4°C. Calibrator sequences have been published as GenBank® accession nos. EF143258 (DNA control, LC) and EF143257 (RNA control, SC). Simultaneous control of DNA and RNA processing efficiency using a nucleic acid calibration se

A molecular beacon, bead-based assay for the detection of nucleic acids by flow cytometry

Molecular beacons are dual-labelled probes that are typically used in real-time PCR assays, but have also been conjugated with solid matrices for use in microarrays or biosensors. We have developed a fluid array system using microsphere-conjugated molecular beacons and the flow cytometer for the specific, multiplexed detection of unlabelled nucleic acids in solution. For this array system, molecular beacons were conjugated with microspheres using a biotin-streptavidin linkage. A bridged conjugation method using streptavidin increased the signal-to-noise ratio, allowing for further discrimination of target quantitation. Using beads of different sizes and molecular beacons in two fluorophore colours, synthetic nucleic acid control sequences were specifically detected for three respiratory pathogens, including the SARS coronavirus in proof-of-concept experiments. Considering that routine flow cytometers are able to detect up to four fluorescent channels, this novel assay may allow for the specific multiplex detection of a nucleic acid panel in a single tube