322 research outputs found
Homeostatic action selection for simultaneous multi-tasking
Mobile robots are rapidly developing and gaining in competence, but the potential
of available hardware still far outstrips our ability to harness. Domain-speciďŹc
applications are most successful due to customised programming tailored to a
narrow area of application. Resulting systems lack extensibility and autonomy,
leading to increased cost of development.
This thesis investigates the possibility of designing and implementing a general
framework capable of simultaneously coordinating multiple tasks that can be added
or removed in a plug and play manner. A homeostatic mechanism is proposed for
resolving the contentions inevitably arising between tasks competing for the use of
the same robot actuators.
In order to evaluate the developed system, demonstrator tasks are constructed to
reach a goal location, prevent collision, follow a contour around obstacles and
balance a ball within a spherical bowl atop the robot.
Experiments show preliminary success with the homeostatic coordination mechanism
but a restriction to local search causes issues that preclude conclusive evaluation.
Future work identiďŹes avenues for further research and suggests switching to a
planner with the sufďŹcient foresight to continue evaluation."This work was supported by the Engineering and Physical Sciences Research Council
[grant number EP/K503162/1]." -- Acknowledgement
Male Control and Female Resistance in American Roots Music Recordings of the Interwar Period
This thesis examines themes of male control and female resistance in commercially recorded American roots music of the interwar period, focusing primarily on recordings made in the years 1920-1940. It argues that much of the roots music recorded during this period communicated powerful messages about gendered and racial hierarchies to consumers. Rooted in close textual analysis of song lyrics and visual marketing materials for a plethora of commercially available roots music, the thesis deploys methodologies drawn from history, literary, cultural studies, and musicology. It questions why scholars have understudied themes of gendered power contestations and social control in commercially recorded roots music and the accompanying marketing materials during the interwar period.
Although scholars have acknowledged intersections of race, class, gender, and the construction of segregated roots music markets during the nascent stages of a rapidly-developing fledgling industry, this thesis contends that lyrical content and marketing materials also intersected with white supremacist and eugenic ideologies, reflecting ideas about social control of women during the interwar period. It advances extant scholarship on black and white female roots music artists active during the interwar period, underscoring and illuminating themes of female resistance to male control, inside and outside of the worlds created on commercial recordings
The genetic control of avascular area in mouse oxygen-induced retinopathy
Purpose:
The C57BL/6ByJ and BALB/cByJ inbred strains of mice are, respectively, susceptible and resistant to oxygen-induced retinopathy (OIR). The purpose of this work was to investigate the genetic control of the retinal avascular area in mouse OIR using a mapping cross.
Methods:
The central retinal avascular area was measured on postnatal day 16 (P16) in C57BL/6ByJ, BALB/cByJ, 101 (C57BL/6ByJ x BALB/cByJ)F2, and 116 (BALB/cByJ x C57BL/6ByJ)F2 mice that had been subjected to the OIR protocol. A genome-wide scan was performed of selected albino and non-albino mice to determine quantitative trait loci associated with weight and avascular area.
Results:
C57BL/6ByJ mice had significantly larger avascular areas than BALB/cByJ ones. Albino mice of the F2 generation had smaller avascular areas than the non-albino mice. Genotyping was performed at 856 informative single nucleotide polymorphisms approximately evenly distributed across the genome from each of 85 selected F2 mice. Weight, sex, and the paternal grandmother were found to act as additive covariates associated with the avascular area on P16; mapping analyses that used a model incorporating these covariates found a quantitative trait locus on chromosome 7 related to avascular area. Mapping analyses that used a model that did not incorporate covariates found a quantitative trait locus on chromosome 9 related to avascular area. A quantitative trait locus for bodyweight on P16 was mapped to chromosome 5.
Conclusions:
The retinal avascular area in the mouse OIR model is under genetic control. Revascularization in OIR is related to the weight, strain of paternal grandmother, sex, and albinism. Our data support the existence of a quantitative trait locus on chromosome 5 that influences weight after exposure to hyperoxia, as well as quantitative trait loci on chromosomes 7 and 9 that modify susceptibility to OIR
A Measurement of the Cosmic Optical Background and Diffuse Galactic Light Scaling from the R < 50 AU New Horizons-LORRI Data
Direct photometric measurements of the cosmic optical background (COB)
provide an important point of comparison to both other measurement
methodologies and models of cosmic structure formation, and permit a cosmic
consistency test with the potential to reveal additional diffuse sources of
emission. The COB has been challenging to measure from Earth due to the
difficulty of isolating it from the diffuse light scattered from interplanetary
dust in our solar system. We present a measurement of the COB using data taken
by the Long-Range Reconnaissance Imager (LORRI) on NASA's New Horizons mission,
considering all data acquired to 47 AU. We employ a blind methodology where our
analysis choices are developed against a subset of the full data set, which is
then unblinded. Dark current and other instrumental systematics are accounted
for, including a number of sources of scattered light. We fully characterize
and remove structured and diffuse astrophysical foregrounds including bright
stars, the integrated starlight from faint unresolved sources, and diffuse
galactic light. For the full data set, we find the surface brightness of the
COB to be 21.98 1.23 (stat.)
1.36 (cal.) nW m sr. This result supports recent
determinations that find a factor of 2 3 more light than
expected from the integrated light from galaxies and motivate new diffuse
intensity measurements with more capable instruments that can support spectral
measurements over the optical and near-IR.Comment: 36 pages, 22 figures, 8 tables; accepted for publication in Ap
Explaining science: integrating science literacy into a research-based undergraduate program
Science literacy, which we define as the writing, reading and information research skills required to practice science, is a central component of the Integrated Science Program (iSci) at McMaster University. Concepts developed in the interactive, collaboratively-taught science literacy classes support the research projects that form the basis of learning in iSci. The aim of the science literacy component is to prepare the next generation of professional scientists to communicate not only within academia, but also to the wider community. In this presentation, we will describe the format of iSci and the role of science literacy within it. We shall then discuss the various activities and techniques used to introduce professional skills throughout the four-year program. iSci students gain experience in writing for audiences through two main conduits. One is a science blog: an on-going, individual, low-stakes writing practice activity. The other is a series of research project assessed deliverables: high-stakes, collaborative writing tasks. These take the form of oral presentations, posters, debates, abstracts, lab reports, and papers. Students are supported in developing writing skills (from research notes, through drafting, review, and editing) by feedback from instructors, dedicated TAs, and their peers. Information literacy skills, including source evaluation and information retrieval, are developed from the start of the Program. iSci has strong links to the University Library and students are introduced to primary literature early in the course. We report on results from the first two years of the science literacy initiative, and outline plans for further developments and evaluations
The genetic control of avascular area in mouse oxygen-induced retinopathy
Purpose:
The C57BL/6ByJ and BALB/cByJ inbred strains of mice are, respectively, susceptible and resistant to oxygen-induced retinopathy (OIR). The purpose of this work was to investigate the genetic control of the retinal avascular area in mouse OIR using a mapping cross.
Methods:
The central retinal avascular area was measured on postnatal day 16 (P16) in C57BL/6ByJ, BALB/cByJ, 101 (C57BL/6ByJ x BALB/cByJ)F2, and 116 (BALB/cByJ x C57BL/6ByJ)F2 mice that had been subjected to the OIR protocol. A genome-wide scan was performed of selected albino and non-albino mice to determine quantitative trait loci associated with weight and avascular area.
Results:
C57BL/6ByJ mice had significantly larger avascular areas than BALB/cByJ ones. Albino mice of the F2 generation had smaller avascular areas than the non-albino mice. Genotyping was performed at 856 informative single nucleotide polymorphisms approximately evenly distributed across the genome from each of 85 selected F2 mice. Weight, sex, and the paternal grandmother were found to act as additive covariates associated with the avascular area on P16; mapping analyses that used a model incorporating these covariates found a quantitative trait locus on chromosome 7 related to avascular area. Mapping analyses that used a model that did not incorporate covariates found a quantitative trait locus on chromosome 9 related to avascular area. A quantitative trait locus for bodyweight on P16 was mapped to chromosome 5.
Conclusions:
The retinal avascular area in the mouse OIR model is under genetic control. Revascularization in OIR is related to the weight, strain of paternal grandmother, sex, and albinism. Our data support the existence of a quantitative trait locus on chromosome 5 that influences weight after exposure to hyperoxia, as well as quantitative trait loci on chromosomes 7 and 9 that modify susceptibility to OIR
Clinical diagnostic utility of IP-10 and LAM antigen levels for the diagnosis of tuberculous pleural effusions in a high burden setting
Background: Current tools for the diagnosis of tuberculosis pleural effusions are sub-optimal. Data about the value of new
diagnostic technologies are limited, particularly, in high burden settings. Preliminary case control studies have identified
IFN-Îł-inducible-10kDa protein (IP-10) as a promising diagnostic marker; however, its diagnostic utility in a day-to-day clinical
setting is unclear. Detection of LAM antigen has not previously been evaluated in pleural fluid.
Methods: We investigated the comparative diagnostic utility of established (adenosine deaminase [ADA]), more recent
(standardized nucleic-acid-amplification-test [NAAT]) and newer technologies (a standardized LAM mycobacterial antigendetection
assay and IP-10 levels) for the evaluation of pleural effusions in 78 consecutively recruited South African
tuberculosis suspects. All consenting participants underwent pleural biopsy unless contra-indicated or refused. The
reference standard comprised culture positivity for M. tuberculosis or histology suggestive of tuberculosis.
Principal Findings: Of 74 evaluable subjects 48, 7 and 19 had definite, probable and non-TB, respectively. IP-10 levels were
significantly higher in TB vs non-TB participants (p<0.0001). The respective outcomes [sensitivity, specificity, PPV, NPV %]
for the different diagnostic modalities were: ADA at the 30 IU/L cut-point [96; 69; 90; 85], NAAT [6; 93; 67; 28], IP-10 at the
28,170 pg/ml ROC-derived cut-point [80; 82; 91; 64], and IP-10 at the 4035 pg/ml cut-point [100; 53; 83; 100]. Thus IP-10,
using the ROC-derived cut-point, missed ~20% of TB cases and mis-diagnosed ~20% of non-TB cases. By contrast, when a
lower cut-point was used a negative test excluded TB. The NAAT had a poor sensitivity but high specificity. LAM antigendetection
was not diagnostically useful.
Conclusion: Although IP-10, like ADA, has sub-optimal specificity, it may be a clinically useful rule-out test for tuberculous
pleural effusions. Larger multi-centric studies are now required to confirm our findings
Validated instruments used to measure attitudes of healthcare students and professionals towards patients with physical disability: a systematic review
<p>Abstract</p> <p>Background</p> <p>Instruments to detect changes in attitudes towards people with disabilities are important for evaluation of training programs and for research. While we were interested in instruments specific for medical students, we aimed to systematically review the medical literature for validated survey instruments used to measure attitudes of healthcare students and professionals towards patients with physical disability.</p> <p>Methods</p> <p>We electronically searched Medline, EMBASE, PsycINFO, Health and Psychosocial Instruments. We included papers reporting on the development and/or validation of survey instruments to measure attitudes of healthcare students and professionals towards patients with physical disability. We excluded papers in which the attitudes were not measured in a provider-patient context. Two reviewers carried out titles and abstracts screening, full texts screening, and data abstraction in a duplicate and independent manner using standardized and pilot tested forms.</p> <p>Results</p> <p>We identified seven validated survey instruments used for healthcare students and professionals. These instruments were originally developed for the following target populations: general population (n = 4); dental students (n = 1); nursing students (n = 1); and rehabilitation professionals (n = 1). The types of validity reported for these instruments were content validity (n = 3), criterion-related validity (n = 1), construct validity (n = 2), face validity (n = 1), discriminant validity (n = 1), and responsiveness (n = 1). The most widely validated and used tool (ATDP) was developed in the late 1960s while the most recent instrument was developed in the early 1990s.</p> <p>Conclusion</p> <p>Of the seven identified validated instruments, less than half were specifically designed for healthcare students and professionals and none for medical students. There is a need to develop and validate a contemporary instrument specifically for medical students.</p
Breast cancer screening beliefs by practice location
BACKGROUND: This study examines variations in breast cancer screening among primary care clinicians by geographic location of clinical practice. METHODS: A cross-sectional survey design was used to examine approaches to breast cancer screening among physicians, nurse practitioners, and physician assistants involved in primary care practice. A summary index of beliefs about breast cancer screening was created by summing the total number of responses in agreement with each of four survey items; values for this summary variable ranged between zero and four. Respondents were classified into urban, rural and suburban categories based upon practise location. RESULTS: Among the 428 respondents, agreement with "correct" responses ranged from 50% to 71% for the individual survey items; overall, half agreed with three or more of the four breast cancer screening items. While no significant differences were noted by practice location, variation in responses were evident. Reported use of written breast cancer guidelines was less in both suburban (OR = 0.51) and urban areas (OR = 0.56) when compared to clinicians in rural areas. CONCLUSION: Development of an evidence-based consensus statement regarding breast cancer screening would support a single set of unambiguous guidelines for implementation in all primary care settings, thus decreasing variations in how breast cancer screening is approached across varied clinical settings
Rapid on-site identification of hazardous organic compounds at fire scenes using person-portable gas chromatography-mass spectrometry (GC-MS). Part 2: Water sampling and analysis
Building and factory fires pose a great risk to human and environmental health, due to the release of hazardous by-products of combustion. These hazardous compounds can dissipate into the environment through fire water run-off, and the impact can be immediate or chronic. Current laboratory-based methods do not report hazardous compounds released from a fire scene at the time and location of the event. Reporting of results is often delayed due to the complexities and logistics of laboratory-based sampling and analysis. These delays pose a risk to the health and wellbeing of the environment and exposed community. Recent developments in person-portable instrumentation have the potential to provide rapid analysis of samples in the field. A portable gas chromatograph-mass spectrometer (GC-MS) was evaluated for the on-site analysis of water samples for the identification of hazardous organic compounds at fire scenes. The portable GC-MS was capable of detecting and identifying a range of volatile and semi-volatile organic compounds in fire water run-off, and can be used in conjunction with conventional laboratory analysis methods for a comprehensive understanding of hazardous organics released at fire scenes. Deployment of this portable instrumentation provides first responders with a rapid, on-site screening tool to appropriately manage the run-off water from firefighting activities. This ensures that environmental and human health is proactively protected
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