394 research outputs found
Self-locking clamping tool with swivel jaws
A plier-like tool (11) having two plier-like members (13, 15) pivotally joined togther intermediate of their ends and having handle portions (17, 18) and swivel jaw members (29,30). An automatic locking mechanism (27) extending between the members permits an user to clamp the handle portions together so as to clamp the jaw members on an object (25) but holds the position so reached if the clamping action of the user is removed. A release device (65) is provided so that the jaw members may be opened up again. A compression spring (23) extending between the members (19, 20) assists in the opening of the jaw members. The swivel jaw members (29, 30) permit the user to rotate the plier-like members (13,15) relative to the object (25) being grasped
Consumer\u27s choice in protective eyewear
Seventeen pairs of racquetball eyewear were tested for distortion and loss of field. Four of the seventeen eyewear produced twenty five percent or greater loss of field. Two of the eyewears produced less than one percent loss of field. None produced measurable distortion utilized by our measurement techniques
The Utility of MRI in Cervical Spine Clearance in Alert Blunt Trauma Patients with Cervical Spine Tenderness and Negative CT Scan
Study Objective: To evaluate the utility of MRI of the cervical spine in alert blunt trauma patients with a GCS of 15 without any neurological deficits who have cervical spine tenderness and a negative CT scan
The Trouble with Knowing: Wikipedian consensus and the political design of encyclopedic media
Encyclopedias are interfaces between knowing and the unknown. They are devices that negotiate the middle ground between incompatible knowledge systems while also performing as dream machines that explore the political outlines of an enlightened society. Building upon the insights from critical feminist theory, media archaeology, and science and technology studies, the dissertation investigates how utopian and impossible desires of encyclopedic media have left a wake of unresolvable epistemological crises.
In a 2011 survey of editors of the online encyclopedia Wikipedia, it was reported that 87 per cent of Wikipedians identified as men. This statistic flew in the face of Wikipedias utopian promise that it was an encyclopedia that anyone can edit. Despite the early optimism and efforts to reduce this disparity, Wikipedias parent organization acknowledged its inability to significantly make Wikipedia more equitable. This matter of concern raised two questions: What kinds of knowing subjects is Wikipedia designed to cultivate and what does this conflict over who is included and excluded within Wikipedia tell us about the utopian dreams that are woven into encyclopedic media? This dissertation argues that answering these troubling questions requires an examination of the details of the present, but also the impossible desires that Wikipedia inherited from its predecessors.
The analysis of these issues begins with a genealogy of encyclopedias, encyclopedists, encyclopedic aesthetics, and encyclopedisms. It is followed by an archeology of the twentieth century deployment of consensus as an encyclopedic and political program. The third part examines how Wikipedia translated the imaginary ideal of consensus into a cultural technique. Finally, the dissertation mobilizes these analyses to contextualize how consensus was used to limit the dissenting activities of Wikipedia's Gender Gap Task Force. The dissertation demonstrates that the desire and design of encircling knowledge through consensus cultivated Wikipedias gender gap. In this context, if encyclopedic knowledge is to remain politically and culturally significant in the twenty-first century, it is necessary to tell a new story about encyclopedic media. It must be one where an attention to utopian imaginaries, practices, and techniques not only addresses how knowledge is communicated but also enables a sensitivity to the question of who can know
Low cost autonomous sensing platforms for the direct determination of nutrients in water
There is a growing need for low cost, remote sensing systems which can be deployed in situ in sufficiently large numbers to ensure that data on key water quality parameters is readily available. The challenges facing this ideal of monitoring include the cost of these platforms and the inability to “deploy and forget” due to limited long term stability and maintenance requirements. Microfluidic technology has great potential as a solution to the increasing demand for environmental monitoring, by producing autonomous chemical sensing platforms at a price level that creates a significant impact on the existing market. The development of sensing platforms for ammonia and nitrate in water and wastewater are being investigated. Our approach is to combine microfluidics with simplified colorimetric chemical assays; low cost LED/photodiode-based optical detection systems; and wireless communications. In order to drive down the cost of these devices, it is vital to keep the fluidic handling requirement as simple as possible, as multistage methods are expensive to implement as well as being less reliable in long-term deployments. Colorimetric methods for nitrate and ammonia have been modified eliminating several steps previously associated with the methods to facilitate their implementation into an autonomous platform, resulting in a rapid and simple measurement procedure
The development of an autonomous sensing platform for the monitoring of ammonia in water using a simplified Berthelot method
This study demonstrates that by combining a modified version of the Berthelot method with microfluidic technologies and LED based optical detection systems, a low cost monitoring system for detection of ammonia in fresh water and wastewater can be developed. The assay developed is a variation on the Berthelot method, eliminating several steps previously associated with the method to create a nontoxic and simple colorimetric assay. The previous Berthelot method required the addition of three reagents, mixed sequentially with the sample, which complicates the microfluidic system design. With the modified method, comparable results were attained using a single reagent addition step at a 1:1 v/v reagent to sample ratio, which significantly simplifies the fluidic handling requirement for integration into an autonomous sensing platform. The intense colour generated in the presence of ammonia is detected at a wavelength of 660 nm. The method allows for ammonia determination up to 12 mg/L NH4+ with a limit of detection of 0.015 mg/L NH4+. Validation was achieved by analysing split water samples by the modified method and by ion chromatography, resulting in an excellent correlation coefficient of 0.9954. The method was then implemented into a fully integrated sensing platform consisting of a sample inlet with filter, storage units for the Berthelot reagent and standards for self-calibration, pumping system which controls the transport and mixing of the sample, a microfluidic mixing and detection chip, and waste storage. The optical detection system consists of a LED light source with a photodiode detector, which enables sensitive detection of the coloured complex formed. The robustness and low cost of the microfluidic platform coupled with integrated wireless communications makes it an ideal platform for in-situ environmental monitoring. This is the first demonstration of a fully functional microfluidic platform employing this modified version of the Berthelot method
Evidence for spatially-responsive neurons in the rostral thalamus
Damage involving the anterior thalamic and adjacent rostral thalamic nuclei may result in a severe anterograde amnesia, similar to the amnesia resulting from damage to the hippocampal formation. Little is known, however, about the information represented in these nuclei. To redress this deficit, we recorded units in three rostral thalamic nuclei in freely-moving rats (the parataenial nucleus, the anteromedial nucleus and nucleus reuniens). We found units in these nuclei possessing previously unsuspected spatial properties. The various cell types show clear similarities to place cells, head direction cells, and perimeter/border cells described in hippocampal and parahippocampal regions. Based on their connectivity, it had been predicted that the anterior thalamic nuclei process information with high spatial and temporal resolution while the midline nuclei have more diffuse roles in attention and arousal. Our current findings strongly support the first prediction but directly challenge or substantially moderate the second prediction. The rostral thalamic spatial cells described here may reflect direct hippocampal/parahippocampal inputs, a striking finding of itself, given the relative lack of place cells in other sites receiving direct hippocampal formation inputs. Alternatively, they may provide elemental thalamic spatial inputs to assist hippocampal spatial computations. Finally, they could represent a parallel spatial system in the brain
Timing of ibuprofen use and musculoskeletal adaptations to exercise training in older adults
AbstractProstaglandins (PGs) increase in bone in response to mechanical loading and stimulate bone formation. Inhibition of cyclooxygenase (COX), the enzyme responsible for PG synthesis, by non-steroidal anti-inflammatory drugs (NSAIDs) impairs the bone formation response to loading in animals when administered before, but not after, loading. The aim was to determine whether the timing of ibuprofen use (400mg before versus after exercise sessions) is a significant determinant of the adaptive response of BMD to exercise training in older adults. We hypothesized that taking ibuprofen before exercise would attenuate the improvements in total hip and lumbar spine BMD in response to 36weeks of training when compared with placebo or with ibuprofen use after exercise. Untrained women and men (N=189) aged 60 to 75years were randomly assigned to 1 of 3 treatment arms: placebo before and after exercise (PP); ibuprofen before and placebo after exercise (IP); and placebo before and ibuprofen after exercise (PI).The difference between groups in the change in BMD was not significant when IP was compared with either PP (hip, −0.5% (−1.4, 0.4); spine, 0.1% (−0.9, 1.2)) or PI (hip, 0.3% (−0.6, 1.2); spine, 0.5% (−0.5, 1.5)). Ibuprofen use appeared to have more adverse effects on BMD in women than men. The study demonstrated that ibuprofen use did not significantly alter the BMD adaptations to exercise in older adults, but this finding should be interpreted cautiously. It had been expected that the inhibition of bone formation by ibuprofen would be more robust in men than in women, but this did not appear to be the case and may have limited the power to detect the effects of ibuprofen. Further research is needed to understand whether NSAID use counteracts, in part, the beneficial effects of exercise on bone
Default mode network segregation and social deficits in autism spectrum disorder: Evidence from non-medicated children DMN in children with ASD
AbstractFunctional pathology of the default mode network is posited to be central to social-cognitive impairment in autism spectrum disorders (ASD). Altered functional connectivity of the default mode network's midline core may be a potential endophenotype for social deficits in ASD. Generalizability from prior studies is limited by inclusion of medicated participants and by methods favoring restricted examination of network function. This study measured resting-state functional connectivity in 22 8–13 year-old non-medicated children with ASD and 22 typically developing controls using seed-based and network segregation functional connectivity methods. Relative to controls the ASD group showed both under- and over-functional connectivity within default mode and non-default mode regions, respectively. ASD symptoms correlated negatively with the connection strength of the default mode midline core—medial prefrontal cortex–posterior cingulate cortex. Network segregation analysis with the participation coefficient showed a higher area under the curve for the ASD group. Our findings demonstrate that the default mode network in ASD shows a pattern of poor segregation with both functional connectivity metrics. This study confirms the potential for the functional connection of the midline core as an endophenotype for social deficits. Poor segregation of the default mode network is consistent with an excitation/inhibition imbalance model of ASD
Identification of a novel population of muscle stem cells in mice: potential for muscle regeneration
Three populations of myogenic cells were isolated from normal mouse skeletal muscle based on their adhesion characteristics and proliferation behaviors. Although two of these populations displayed satellite cell characteristics, a third population of long-time proliferating cells expressing hematopoietic stem cell markers was also identified. This third population comprises cells that retain their phenotype for more than 30 passages with normal karyotype and can differentiate into muscle, neural, and endothelial lineages both in vitro and in vivo. In contrast to the other two populations of myogenic cells, the transplantation of the long-time proliferating cells improved the efficiency of muscle regeneration and dystrophin delivery to dystrophic muscle. The long-time proliferating cells' ability to proliferate in vivo for an extended period of time, combined with their strong capacity for self-renewal, their multipotent differentiation, and their immune-privileged behavior, reveals, at least in part, the basis for the improvement of cell transplantation. Our results suggest that this novel population of muscle-derived stem cells will significantly improve muscle cell–mediated therapies
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