Magnetic resonance imaging kinematics of the Posterior Cruciate deficient knee

The aim of this thesis is to compare the sagittal plane articulation of the Tibiofemoral joint of the Posterior Cruciate Ligament (PCL) deficient knee with the healthy knee and the contralateral uninjured knee. Difference in the articulation profile may help to explain the predominance of medial compartment degeneration seen arthroscopically in PCL injured knees. Analysis of the kinematics of the contralateral knee may help elicit predisposing kinematic abnormalities to PCL injuries and also test the validity of using the contralateral knee as a control. Magnetic resonance was used to generate sagittal images of ten healthy knees and ten knees with isolated PCL injuries. The subjects performed a supine leg press against a 150N load. Images were generated at 15 degree intervals as the knee flexed from 0 to 900. The Tibiofemoral Contact (TFC) and the Flexion Facet Centre (FFC) were measured from the posterior tibial cortex. The contact pattern and FFC was significantly more anterior in the injured knee from 45 to 900 of knee flexion in the medial compartment compared to the healthy knee. The greatest difference between the mean TFC points of both groups occurred at 75 and 900, the difference being 4 mm and 5 mm respectively. The greatest difference between the mean FFC of both groups occurred at 750 of flexion, which was 3 mm. There was no significant difference in the contact pattern and FFC between the injured and healthy knees in the lateral compartment. There was no significant difference in the TFC and FFC between the healthy knee and contralateral knee of subjects with acute and chronic PCL injuries in the medial and lateral compartments of the knee. The study demonstrates that there is a significant difference in the medial compartment sagittal plane articulation of the tibiofemoral joint in subjects with an isolated PCL injury. Further, this study suggests there is no predisposing articulation abnormality to PCL injury. That is, in the setting of chronic injury the contralateral knee does not modify its articulation profile and the contralateral knee can be used as a valid control when evaluating the articulation of the PCL deficient knee

Our future in space: The physical and virtual opening-up of parliaments to publics

Parliaments are physical symbols of nationhood and democracy. Public access to these spaces is often strictly regulated, yet it remains highly influential to public experiences of parliament (and their engagement with it). Drawing on data collected for the Inter-Parliamentary Union’s 2022 Global Parliamentary Report, this article discusses ways in which parliamentary ‘space’ can be utilised to encourage public engagement. This encompasses the effective use of physical space, virtual reality and augmented reality for the purpose of public engagement. In doing so, we show the most important and effective strategy for (re)using, and opening up, parliamentary spaces: the complementary use of physical and virtual methods in not only bringing publics to parliament, but also bringing parliament to publics

Statistical evaluation of motorist and pedestrian behavior at signalized intersections in Las Vegas

This study examines the effect of a law enforcement program implemented to check illegal and unsafe motorist and pedestrian behavior. A case study involving eight selected intersections in Las Vegas (four control and four treatment) was carried out over a period of seven months in conjunction with the pedestrian law enforcement program conducted during March and April of 1996. Pedestrian and motorist behaviors were video taped in 120 minute segments. The tapes were then reviewed to count vehicle violations, pedestrian violations, conflicts, total vehicles and total pedestrians. Violations and conflict rates for pre and during enforcement, and pre and post enforcement phases were compared using the Wilcoxon signed rank test - matched pairs. Regression analyses were then conducted to determine the effect of intersection design characteristics on violations and conflicts; The results from the nonparametric statistical tests suggest that the law enforcement program did not have any long term impact on reducing pedestrian violations, vehicle violations and conflicts. The results from the regression analysis identified pedestrian volume as a significantly consistent explanatory variable for the dependent variable pedestrian violations . Likewise vehicle violations and with signal outside crosswalk violations showed up as significantly consistent explanatory variables for the dependent variable conflicts

Prevention of Casuality in Automobiles due to Air conditioners

Now a day the rate of deaths are increased because of sleeping in the automobiles with Air conditioner. In our project we have proposed a concept to prevent the death during such situations. The causes of death are because of the presence of carbon monoxide and R134A [Refrigerant] in air conditioning. Here we are using two different gas sensors to measure the values of both the gases in safer levels. We are using Arduino to control the levels of gases which won’t cause any death. The control of gases is done by indication the people through alarm / buzzer at minimum level were people will be in conscious state and by opening the power windows at maximum level when they are in unconscious state

Usability evaluation of a Self-levelling robotic wheelchair for tip prevention in outdoor environments

Tips and falls are the most prominent causes of wheelchair accidents in the US when driving on uneven terrains and non-accessible environments. The Mobility Enhancement Robotic Wheelchair (MEBot) was designed to tackle these environmental challenges and address the mobility limitations of conventional electric-powered wheelchairs (EPW). MEBot offers a self-leveling application to maintain a stable seat in uneven terrains with the use of position sensors at each wheel and an attitude sensor to move each wheel accordingly. The self-leveling application can be enabled/disabled via a switch. The goal of the study was to perform a usability evaluation of MEBot’s self-leveling application in terms of the wheelchair’s performance and the participant’s perception. Ten participants were asked to drive their own EPW and MEBot through a driving course that simulated outdoor environmental obstacles for five times in each device. The wheelchair’s performance hypotheses included MEBot’s ability to be safe by maintaining a lower change in seat angle change than participants’ EPWs and MEBot’s self-leveling time would be within or lower than an average person’s walking speed. Additionally, it was hypothesized that participants would score better on the NASA-TLX and QUEST assessment tools for MEBot than their own EPW. Results showed that MEBot has lower angle change when going up and down a 10° slope; MEBot (5.6° ± 1.6°, 6.6° ± 0.5°) than their own wheelchair (14.6° ± 2.6°, 12.1° ± 2.6°) absolute deviation going up and down the slope, respectively. This contrasts with the participants’ EPWs when ascending and descending both slopes as MEBot required a longer time (7.8 ± 3.0 seconds) with a greater angle change when driving over an obstacle. The participant’s perception towards each EPW favored MEBot with respect to the NASA TLX and QUEST than their own wheelchair based upon the interpretation of the written feedback. The results demonstrated that the self-leveling application can work effectively but it is hindered by mechanical limitations. Future work will involve a redesign with electro-hydraulic actuators to mitigate this mechanical limitation and similar usability evaluation to evaluate MEBot improvements

Nanoscale patterning with block copolymers

The self-assembly processes of block copolymers offer interesting strategies to create patterns on nanometer length scales. The polymeric constituents, substrate surface properties, and experimental conditions all offer parameters that allow the control and optimization of pattern formation for specific applications. We review how such patterns can be obtained and discuss some potential applications using these patterns as (polymeric) nanostructures or templates, e.g. for nanoparticle assembly. The method offers interesting possibilities in combination with existing high-resolution lithography methods, and could become of particular interest in microtechnology and biosensing

Enhancing Memory by Enactment: Does Meaning Underlie the Advantage of Producing or Observing an Action?

Enactment is an encoding strategy in which performing an action depicting a word (relative to reading) enhances its memorability. Precisely how this motor activity aids recall is unclear. In our Experiments, we investigated whether actions needed to convey meaningful information about the verbal target to confer a memory benefit. In Experiment 1 (Chapter 2), participants were asked to either a) enact, b) perform unrelated motoric gestures, or c) passively read forty-five visually-presented action verbs shown sequentially, and intermixed during encoding, in a within-subjects design. We found that enacted words were recalled significantly better than words read or gestured at encoding. In Experiment 2 (Chapter 2), to control for ambiguity in gesture initiation, participants were specifically instructed to write target words in the air on “unrelated gesture” encoding trials. Results were similar to Experiment 1. In Experiment 3, we aimed to replicate the results of Experiment 2 using an online platform to be able to video record the onset time of actions initiated in response to verbal targets, as a measure of action planning. Chapter 2 experiments showed 1) that meaningful or task-related action produced at encoding is critical to the enactment effect, and that 2) planning of meaningful actions may also contribute to the memory performance. In Experiment 4 (Chapter 3), we asked whether the performed action needed to be semantically relevant, and whether it needed to be performed by the subject (relative to observing the action of an experimenter), to confer a memory benefit. As in our previous experiments, the semantic relevance of actions to items was found to be important for the memory benefit. Importantly, the magnitude of the enactment benefit was greater when participants performed rather than observed the actions of a researcher. Results from Chapter 3 suggest that a social presence may contribute to the magnitude of past reported effects of action observation. Overall, this thesis shows that (1) semantic relevance of actions produced at encoding is critical for the observed memory boost, and (2) planning of task-relevant actions highlights another key component by which enactment benefit memory