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Description
The interaction between visual fixations during planning and performance in a

dexterous task was analyzed. An eye-tracking device was affixed to subjects during

sequences of null (salient center of mass) and weighted (non salient center of mass) trials

with unconstrained precision grasp. Subjects experienced both expected and unexpected

perturbations, with the task of minimizing

The interaction between visual fixations during planning and performance in a

dexterous task was analyzed. An eye-tracking device was affixed to subjects during

sequences of null (salient center of mass) and weighted (non salient center of mass) trials

with unconstrained precision grasp. Subjects experienced both expected and unexpected

perturbations, with the task of minimizing object roll. Unexpected perturbations were

controlled by switching weights between trials, expected perturbations were controlled by

asking subjects to rotate the object themselves. In all cases subjects were able to

minimize the roll of the object within three trials. Eye fixations were correlated with

object weight for the initial context and for known shifts in center of mass. In subsequent

trials with unexpected weight shifts, subjects appeared to scan areas of interest from both

contexts even after learning present orientation.
ContributorsSmith, Michael David (Author) / Santello, Marco (Thesis advisor) / Buneo, Christopher (Committee member) / Schaefer, Sydney (Committee member) / Arizona State University (Publisher)
Created2017
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Description
The human hand is a complex biological system. Humans have evolved a unique ability to use the hand for a wide range of tasks, including activities of daily living such as successfully grasping and manipulating objects, i.e., lifting a cup of coffee without spilling. Despite the ubiquitous nature of hand

The human hand is a complex biological system. Humans have evolved a unique ability to use the hand for a wide range of tasks, including activities of daily living such as successfully grasping and manipulating objects, i.e., lifting a cup of coffee without spilling. Despite the ubiquitous nature of hand use in everyday activities involving object manipulations, there is currently an incomplete understanding of the cortical sensorimotor mechanisms underlying this important behavior. One critical aspect of natural object grasping is the coordination of where the fingers make contact with an object and how much force is applied following contact. Such force-to-position modulation is critical for successful manipulation. However, the neural mechanisms underlying these motor processes remain less understood, as previous experiments have utilized protocols with fixed contact points which likely rely on different neural mechanisms from those involved in grasping at unconstrained contacts. To address this gap in the motor neuroscience field, transcranial magnetic stimulation (TMS) and electroencephalography (EEG) were used to investigate the role of primary motor cortex (M1), as well as other important cortical regions in the grasping network, during the planning and execution of object grasping and manipulation. The results of virtual lesions induced by TMS and EEG revealed grasp context-specific cortical mechanisms underlying digit force-to-position coordination, as well as the spatial and temporal dynamics of cortical activity during planning and execution. Together, the present findings provide the foundation for a novel framework accounting for how the central nervous system controls dexterous manipulation. This new knowledge can potentially benefit research in neuroprosthetics and improve the efficacy of neurorehabilitation techniques for patients affected by sensorimotor impairments.
ContributorsMcGurrin, Patrick M (Author) / Santello, Marco (Thesis advisor) / Helms-Tillery, Steve (Committee member) / Kleim, Jeff (Committee member) / Davare, Marco (Committee member) / Arizona State University (Publisher)
Created2017
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Description

The human hand has so many degrees of freedom that it may seem impossible to control. A potential solution to this problem is “synergy control” which combines dimensionality reduction with great flexibility. With applicability to a wide range of tasks, this has become a very popular concept. In this review,

The human hand has so many degrees of freedom that it may seem impossible to control. A potential solution to this problem is “synergy control” which combines dimensionality reduction with great flexibility. With applicability to a wide range of tasks, this has become a very popular concept. In this review, we describe the evolution of the modern concept using studies of kinematic and force synergies in human hand control, neurophysiology of cortical and spinal neurons, and electromyographic (EMG) activity of hand muscles. We go beyond the often purely descriptive usage of synergy by reviewing the organization of the underlying neuronal circuitry in order to propose mechanistic explanations for various observed synergy phenomena. Finally, we propose a theoretical framework to reconcile important and still debated concepts such as the definitions of “fixed” vs. “flexible” synergies and mechanisms underlying the combination of synergies for hand control.

ContributorsSantello, Marco (Author) / Baud-Bovy, Gabriel (Author) / Jorntell, Henrik (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created2013-04-08
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Description

Insulin-like growth factor 1 (IGF1) is an important biomarker for the management of growth hormone disorders. Recently there has been rising interest in deploying mass spectrometric (MS) methods of detection for measuring IGF1. However, widespread clinical adoption of any MS-based IGF1 assay will require increased throughput and speed to justify

Insulin-like growth factor 1 (IGF1) is an important biomarker for the management of growth hormone disorders. Recently there has been rising interest in deploying mass spectrometric (MS) methods of detection for measuring IGF1. However, widespread clinical adoption of any MS-based IGF1 assay will require increased throughput and speed to justify the costs of analyses, and robust industrial platforms that are reproducible across laboratories. Presented here is an MS-based quantitative IGF1 assay with performance rating of >1,000 samples/day, and a capability of quantifying IGF1 point mutations and posttranslational modifications. The throughput of the IGF1 mass spectrometric immunoassay (MSIA) benefited from a simplified sample preparation step, IGF1 immunocapture in a tip format, and high-throughput MALDI-TOF MS analysis. The Limit of Detection and Limit of Quantification of the resulting assay were 1.5 μg/L and 5 μg/L, respectively, with intra- and inter-assay precision CVs of less than 10%, and good linearity and recovery characteristics. The IGF1 MSIA was benchmarked against commercially available IGF1 ELISA via Bland-Altman method comparison test, resulting in a slight positive bias of 16%. The IGF1 MSIA was employed in an optimized parallel workflow utilizing two pipetting robots and MALDI-TOF-MS instruments synced into one-hour phases of sample preparation, extraction and MSIA pipette tip elution, MS data collection, and data processing. Using this workflow, high-throughput IGF1 quantification of 1,054 human samples was achieved in approximately 9 hours. This rate of assaying is a significant improvement over existing MS-based IGF1 assays, and is on par with that of the enzyme-based immunoassays. Furthermore, a mutation was detected in ∼1% of the samples (SNP: rs17884626, creating an A→T substitution at position 67 of the IGF1), demonstrating the capability of IGF1 MSIA to detect point mutations and posttranslational modifications.

ContributorsOran, Paul (Author) / Trenchevska, Olgica (Author) / Nedelkov, Dobrin (Author) / Borges, Chad (Author) / Schaab, Matthew (Author) / Rehder, Douglas (Author) / Jarvis, Jason (Author) / Sherma, Nisha (Author) / Shen, Luhui (Author) / Krastins, Bryan (Author) / Lopez, Mary F. (Author) / Schwenke, Dawn (Author) / Reaven, Peter D. (Author) / Nelson, Randall (Author) / Biodesign Institute (Contributor)
Created2014-03-24
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Description

Pure coconut oil, lanolin, and acetaminophen were vaporized at rates of 1–50 mg/min, using a porous network exhibiting a temperature gradient from 5000 to 5500 K/mm, without incurring noticeable chemical changes due to combustion, oxidation, or other thermally-induced chemical structural changes. The newly coined term “ereptiospiration” is used here to

Pure coconut oil, lanolin, and acetaminophen were vaporized at rates of 1–50 mg/min, using a porous network exhibiting a temperature gradient from 5000 to 5500 K/mm, without incurring noticeable chemical changes due to combustion, oxidation, or other thermally-induced chemical structural changes. The newly coined term “ereptiospiration” is used here to describe this combination of thermal transpiration at high temperature gradients since the process can force the creation of thermal aerosols by rapid heating in a localized zone. Experimental data were generated for these materials using two different supports for metering the materials to the battery powered coil: namely, a stainless steel fiber bundle and a 3-D printed steel cartridge. Heating coconut oil, lanolin, or acetaminophen in a beaker to lower temperatures than those achieved at the surface of the coil showed noticeable and rapid degradation in the samples, while visual and olfactory observations for ereptiospiration showed no noticeable degradation in lanolin and coconut oil while HPLC chromatograms along with visual observation confirm that within the limit of detection, acetaminophen remains chemically unaltered by ereptiospiration.

ContributorsWoolley, Christine (Author) / Garcia, Antonio (Author) / Santello, Marco (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created2017-04-12
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Description

Contemporary human populations conform to ecogeographic predictions that animals will become more compact in cooler climates and less compact in warmer ones. However, it remains unclear to what extent this pattern reflects plastic responses to current environments or genetic differences among populations. Analyzing anthropometric surveys of 232,684 children and adults

Contemporary human populations conform to ecogeographic predictions that animals will become more compact in cooler climates and less compact in warmer ones. However, it remains unclear to what extent this pattern reflects plastic responses to current environments or genetic differences among populations. Analyzing anthropometric surveys of 232,684 children and adults from across 80 ethnolinguistic groups in sub-Saharan Africa, Asia and the Americas, we confirm that body surface-to-volume correlates with contemporary temperature at magnitudes found in more latitudinally diverse samples (Adj. R2 = 0.14-0.28). However, far more variation in body surface-to-volume is attributable to genetic population structure (Adj. R2 = 0.50-0.74). Moreover, genetic population structure accounts for nearly all of the observed relationship between contemporary temperature and body surface-to-volume among children and adults. Indeed, after controlling for population structure, contemporary temperature accounts for no more than 4% of the variance in body form in these groups. This effect of genetic affinity on body form is also independent of other ecological variables, such as dominant mode of subsistence and household wealth per capita. These findings suggest that the observed fit of human body surface-to-volume with current climate in this sample reflects relatively large effects of existing genetic population structure of contemporary humans compared to plastic response to current environments.

ContributorsHruschka, Daniel (Author) / Hadley, Craig (Author) / Brewis, Alexandra (Author) / Stojanowski, Christopher (Author) / College of Liberal Arts and Sciences (Contributor)
Created2015-03-27
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Description

Background: The transition from the home to college is a phase in which emerging adults shift toward more unhealthy eating and physical activity patterns, higher body mass indices, thus increasing risk of overweight/obesity. Currently, little is understood about how changing friendship networks shape weight gain behaviors. This paper describes the recruitment,

Background: The transition from the home to college is a phase in which emerging adults shift toward more unhealthy eating and physical activity patterns, higher body mass indices, thus increasing risk of overweight/obesity. Currently, little is understood about how changing friendship networks shape weight gain behaviors. This paper describes the recruitment, data collection, and data analytic protocols for the SPARC (Social impact of Physical Activity and nutRition in College) study, a longitudinal examination of the mechanisms by which friends and friendship networks influence nutrition and physical activity behaviors and weight gain in the transition to college life.

Methods: The SPARC study aims to follow 1450 university freshmen from a large university over an academic year, collecting data on multiple aspects of friends and friendship networks. Integrating multiple types of data related to student lives, ecological momentary assessments (EMAs) are administered via a cell phone application, devilSPARC. EMAs collected in four 1-week periods (a total of 4 EMA waves) are integrated with linked data from web-based surveys and anthropometric measurements conducted at four times points (for a total of eight data collection periods including EMAs, separated by ~1 month). University databases will provide student card data, allowing integration of both time-dated data on food purchasing, use of physical activity venues, and geographical information system (GIS) locations of these activities relative to other students in their social networks.

Discussion: Findings are intended to guide the development of more effective interventions to enhance behaviors among college students that protect against weight gain during college.

ContributorsBruening, Meg (Author) / Ohri-Vachaspati, Punam (Author) / Brewis, Alexandra (Author) / Laska, Melissa (Author) / Todd, Michael (Author) / Hruschka, Daniel (Author) / Schaefer, David (Author) / Whisner, Corrie (Author) / Dunton, Genevieve (Author) / College of Health Solutions (Contributor)
Created2016-08-30
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Description
Ethnic groups experience different societal and economic circumstances that contribute to their well-being. Life satisfaction and happiness are commonly used as a measure of well-being; but they are not often used to evaluate well-being in lower income countries. This study focuses on the self-reported life satisfaction and happiness of members

Ethnic groups experience different societal and economic circumstances that contribute to their well-being. Life satisfaction and happiness are commonly used as a measure of well-being; but they are not often used to evaluate well-being in lower income countries. This study focuses on the self-reported life satisfaction and happiness of members of ethnic groups from low- and middle-income countries and its correlation with ethnic privilege, gender opportunity, and income. Using two self-reported measures of well-being—life satisfaction and happiness—among 110,391 women in 27 countries (ages 15-49) surveyed in Multiple Indicator Cluster Surveys, this study examines how country-level indicators of gender opportunity, ethnic-level indicators of privilege and household-level measures of wealth are associated with well-being. Our findings indicate a significant relationship between ethnic privilege, gender opportunity and income on life satisfaction. The results from this study provide valuable data and implications for lower income countries to identify and reduce modifiable risk factors that affect a population’s well-being.
ContributorsChavez Lopez, Giselle (Co-author, Co-author) / Hruschka, Daniel (Thesis director) / Gonzales, Angela (Committee member) / School of Molecular Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
The lonely, empty face panhandling on the street corner has a story to tell. At first glance, most people write the homeless off as less than worthy. However, there is a deeper connection and understanding of relationships and a sense of community unseen by the majority of passer-byers. Amidst the

The lonely, empty face panhandling on the street corner has a story to tell. At first glance, most people write the homeless off as less than worthy. However, there is a deeper connection and understanding of relationships and a sense of community unseen by the majority of passer-byers. Amidst the humdrum beat of every day life, there is toil to find basic necessities such as food, water, sanitation, and a place to rest. At the same time, there is laughter and friendship as they help one another through the hostilities of their circumstances. Combining the creative elements of photojournalism and qualitative interviewing, the basic daily needs and struggles of the homeless will be delved into to answer how friendship is pertinent to survival on the streets.
ContributorsFisher, Meghan (Author) / Hruschka, Daniel (Thesis director) / Hita, Liza (Committee member) / Newland, Judy (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12
Description
Examining the effect of various factors such as class, gender, and status on health inequalities in India is crucial for improving access to health services. However, most research on castes in India is done using broad, government-defined categories, including “Scheduled Castes,” “Scheduled Tribes,” “Forward Classes,” and “Other Backwards Classes.” These

Examining the effect of various factors such as class, gender, and status on health inequalities in India is crucial for improving access to health services. However, most research on castes in India is done using broad, government-defined categories, including “Scheduled Castes,” “Scheduled Tribes,” “Forward Classes,” and “Other Backwards Classes.” These general categories erase the experiences that more specific caste groups have in their health and their livelihood. Using the 2015-2016 Demographic and Health Survey of India, this study analyzes data on 699,686 women aged 15-49 to investigate the association of socioeconomic status, assessed by wealth, education, and community status on two types of contraceptive use–sterilization and other modern methods. Those with secondary education or higher were much less likely to be sterilized and more likely to use non-sterilization forms of modern contraception. Interestingly, those with greater household wealth were more likely to be sterilized but had no different chance of using non-sterilization forms of modern contraception. After controlling for other socioeconomic factors, members of Scheduled Castes and Backward Classes are more likely to be sterilized. However, there was additional heterogeneity between groups, with Muslim groups and Northeastern tribes much less likely to be sterilized, and Southern tribes more likely to be sterilized. Moreover, Muslim groups as well as Northern and Northeastern tribes were more likely to use non-sterilizations forms of contraception, whereas Southern tribes were less likely to use non-sterilization forms of contraception. These findings illustrate that in addition to differences by major caste categories, there is still religious and regional variation in the likelihood of using different forms of contraception. Future research should examine how unique community factors erased within the already present government caste system can affect health. In addition, more research should be done on the various effects of discrimination faced by these communities and how this discrimination affects their health education, access, and autonomy.
ContributorsChandra, Natasha (Author) / Hruschka, Daniel (Thesis director) / Drake, Alexandria (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of International Letters and Cultures (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2024-05