A Coherent Through-Wall MIMO Phased Array Imaging Radar based on Time-Duplexed Switching

Through-the-Wall (TW) radar sensors are gaining increasing interest for security, surveillance and search and rescue applications. Additionally, the integration of Multiple-Input, Multiple-Output (MIMO) techniques with phased array radar is allowing higher performance at lower cost. In this paper we present a 4-by-4 TW MIMO phased array imaging radar operating at 2.4 GHz with 200 MHz bandwidth. To achieve high imaging resolution in a cost-effective manner, the 4 Tx and 4 Rx elements are used to synthesize a uniform linear array (ULA) of 16 virtual elements. Furthermore, the transmitter is based on a single-channel 4-element time-multiplexed switched array. In transmission, the radar utilizes frequency modulated continuous wave (FMCW) waveforms that undergo de-ramping on receive to allow digitization at relatively low sampling rates, which then simplifies the imaging process. This architecture has been designed for the short-range TW scenarios envisaged, and permits sufficient time to switch between antenna elements. The paper first outlines the system characteristics before describing the key signal processing and imaging algorithms which are based on traditional Fast Fourier Transform (FFT) processing. These techniques are implemented in LabVIEW software. Finally, we report results from an experimental campaign that investigated the imaging capabilities of the system and demonstrated the detection of personnel targets. Moreover, we show that multiple targets within a room with greater than approximately 1 meter separation can be distinguished from one another

Numerical Analysis of the Changes in Dense Medium Feed Solids on Dense Medium Cyclone Performance

Numerical simulations of changes in feed medium solids on dense medium cyclone performance were performed using a multi-phase mixture CFD (Computational Fluid Dynamics) model for medium and air-core coupled with Lagrangian model for coal particles for a 350mm DSM cyclone. The turbulence was resolved using Large Eddy Simulation (LES). The mixture model considered the interactions between water and solid phases in terms of hindered settling, lift and Bagnold forces at high feed medium solid loadings. The medium properties were modified by changing the particle size distribution and concentration. Three different medium sizes (ultrafine, superfine and fine) were used in the simulations. The effect of medium stability and rheology on DMC performance is related to feed medium size in terms of density differential and medium segregation. The simulations predicted low Ep (Ecort probability) values with finer medium which gives high separation efficiency on density. A reduction in cyclone efficiency observed for a given feed medium solids distribution at higher feed medium concentrations due to an increase in slurry viscosit

2-Axis Electric Off-Road Bucket Seat Bases

Off-road vehicle bucket seats are currently restricted to a single position relative to the floor of the vehicle. Drivers and riders desire the ability to adjust their seat position to increase comfort and allow for a greater size range of riders to fit safely within the cabin or roll cage. To develop a viable solution, the team has gone through an extensive design process and has constructed a functioning prototype. This Final Design Report encapsulates the entire design process and concludes with recommendations for changes we would make looking both back in review as well as moving forward with further iterations of the product

Initiating Patient Discussions about Oocyte Cryopreservation: Attitudes of Obstetrics and Gynaecology Resident Physicians

This study examined the attitudes of obstetrics and gynaecology (OB/GYN) resident physicians to initiating patient discussions regarding medical and elective oocyte cryopreservation (OC). The study used a cross-sectional online survey of OB/GYN medical residents in the USA, sampled from residency programmes approved by the American Council for Graduate Medical Education. In total, 208 medical residents, distributed evenly between postgraduate years 1–4, participated in the study. Residents\u27 fertility knowledge and attitudes to initiating discussions about OC were gathered. Forty percent (n = 83) believed that OB/GYN residents should initiate discussions about OC with patients (initiators), while 60% (n = 125) did not (non-initiators). Initiators were less likely to overestimate the age at which a woman\u27s fertility begins to decline, and were more likely to believe that discussions about OC and age-related fertility decline should take place during a well-woman annual examination. Initiators and non-initiators did not differ in their attitudes towards discussing OC with patients undergoing cancer treatments; however, initiators were significantly more likely to discuss elective OC with patients who were currently unpartnered or who wished to delay childbearing to pursue a career. Given the increasing age of childbearing among women, and the fact that women prefer to receive reproductive information from their healthcare providers, it is critical that such topics are discussed in consultations to assist patients in making more informed reproductive decisions. Further research is needed to assess the existing barriers to these discussions from both physician and patient perspectives

Knowledge, Attitudes, and Intentions Toward Fertility Awareness and Oocyte Cryopreservation Among Obstetrics and Gynecology Resident Physicians

STUDY QUESTION What knowledge, attitudes and intentions do US obstetrics and gynecology (OB/GYN) residents have toward discussing age-related fertility decline and oocyte cryopreservation with their patients? SUMMARY ANSWER Most OB/GYN residents believe that age-related fertility decline, but not oocyte cryopreservation, should be discussed during well-woman annual exams; furthermore, nearly half of residents overestimated the age at which female fertility markedly declines. WHAT IS KNOWN ALREADY Oocyte cryopreservation can be utilized to preserve fertility potential. Currently, no studies of US OB/GYN residents exist that question their knowledge, attitudes, and intentions toward discussing age-related fertility decline and oocyte cryopreservation with patients. STUDY DESIGN, SIZE, DURATION A cross-sectional online survey was conducted during the fall of 2014 among residents in American Council for Graduate (ACOG) Medical Education-approved OB/GYN residency programs. Program directors were emailed via the ACOG Council on Resident Education in Obstetrics and Gynecology server listing and asked to solicit resident participation. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants included 238 residents evenly distributed between post-graduate years 1–4 with varied post-residency plans; 90% of residents were women and 75% were 26–30 years old. The survey was divided into three sections: demographics, fertility awareness, and attitudes toward discussing fertility preservation options with patients. Descriptive and inferential statistics were conducted. MAIN RESULTS AND THE ROLE OF CHANCE A strong majority of residents (83%) believed an OB/GYN should initiate discussions about age-related fertility decline with patients (mean patient age 31.8), and 73% percent believed these discussions should be part of an annual exam. One third of residents overestimated the age at which there is a slight decline in female fertility, while nearly half of residents overestimated the age at which female fertility markedly declines. Over three-quarters of residents (78.4%) also overestimated the likelihood of success using assisted reproductive treatments (ARTs). Residents were likely to support oocyte cryopreservation in cancer patients irrespective of the woman\u27s age, but much less likely to support elective oocyte cryopreservation. For elective oocyte cryopreservation, 40% believed OB/GYNs should initiate discussions with patients (mean age 31.1), while only 20% believed this topic should be part of an annual exam. LIMITATIONS, REASONS FOR CAUTION Because the study invitation was sent through US OB/GYN residency program directors rather than directly to residents, it is possible that some residents did not receive the invitation to participate. This limits the generalizability of the findings. WIDER IMPLICATIONS OF THE FINDINGS Within the USA, there appears to be a critical need for improved education on fertility decline in OB/GYN residency programs. To promote informed reproductive decision-making among patients, efforts should be made to help OB/GYNs provide comprehensive fertility education to all women, while also respecting patient choices

Feasibility and acceptability of a home-based physical activity program for postnatal women with depressive symptoms: A pilot study

Background Most postnatal women are inactive. Since new mothers, particularly those with heightened depressive symptoms experience several challenges to being active such as lack of time and childcare, home-based programs using hired exercise equipment may help overcome these barriers. This study tested the feasibility and acceptability of a home based treadmill intervention among postpartum women with heightened depressive symptoms. Methods Participants were 11 new mothers (3–9 months postpartum) who at baseline were insufficiently active and experiencing heightened depressive symptoms (based on the Edinburgh Postnatal Depression Scale). Following participation in a 12-week physical activity support program (which included free treadmill hire and access to a purposely designed smartphone web-app), semi-structured interviews were conducted with participants. Depressive symptoms were assessed at weeks 4 and 8 and change in depressive symptoms was analysed using repeated-measures analysis of variance (ANOVA). Thematic analyses were used to identify key themes in qualitative data. Results Quantitative data showed that there was a significant change over time with depressive symptoms decreasing from weeks 0–4 (mean difference = −5.9, 95% CI = −8.7, −5.5) and overall from weeks 0–8 (mean difference = −7.6, 95% CI = −9.8, −3.1). Postpartum women perceived the program to be convenient, flexible and acceptable. Women suggested that the program was useful in overcoming key barriers to physical activity and perceived that the program increased their physical activity and improved psychological health. Conclusion A home-based physical activity program involving cost-free exercise equipment hire was feasible and well accepted by postpartum women. The effectiveness of this program for increasing physical activity and improving mental health in this population should be further tested

An Acoustic Charge Transport Imager for High Definition Television Applications: Low-Voltage SAW Amplifiers on Multilayer GaAs/ZnO Substrates

This thesis addresses the acoustoelectric issues concerning the amplification of surface acoustic waves (SAWs) and the reflection of SAWs from slanted reflector gratings on GaAs, with application to a novel acoustic charge transport (ACT) device architecture. First a simple model of the SAWAMP was developed, which was subsequently used to define the epitaxially grown material structure necessary to provide simultaneously high resistance and high electron mobility. In addition, a segmented SAWAMP structure was explored with line widths on the order of an acoustic wavelength. This resulted in the demonstration of SAWAMPS with an order of magnitude less voltage and power requirements than previously reported devices. A two-dimensional model was developed to explain the performance of devices with charge confinement layers less then 0.5 mm, which was experimentally verified. This model was extended to predict a greatly increased gain from the addition of a ZnO overlay. These overlays were experimentally attempted, but no working devices were reported due to process incompatibilities. In addition to the SAWAMP research, the reflection of SAWs from slanted gratings on GaAs was also studied and experimentally determined reflection coefficients for both 45 deg grooves and Al stripes on GaAs have been reported for the first time. The SAWAMp and reflector gratings were combined to investigate the integrated ring oscillator for application to the proposed ACT device and design parameters for this device have been provided

Clinical effectiveness of baclofen for the treatment of alcohol dependence: A review

Baclofen, an agonist at the B subunit of gaba-aminobutyric acid receptor, possesses pharmacologic properties that may confer utility for the treatment of alcohol dependence. Research suggests that not only can it be useful in promoting maintenance of alcohol abstinence but also it may play a key role in decreasing alcohol cravings and anxiety often associated with alcohol dependence. To assess the benefit of baclofen for alcohol dependence, a review of the literature was conducted to identify published data investigating this off-label treatment. Four randomized controlled trials to date have been published and were included in this review. Although primary outcomes differ between studies, patients randomized to baclofen experience higher rates of abstinence from alcohol than those taking placebo in two of the trials. Secondary analyses indicate that baclofen is safe in patients with alcohol dependence, including those with moderate to severe liver cirrhosis, and may provide beneficial anxiolytic effects. Despite some positive data, the largest available randomized controlled trial failed to find any differences between baclofen and placebo. In all studies, individuals with severe medical comorbidities, seizure disorders, and psychiatric disorders were excluded from trials, which may limit external validity. In summary, there may be beneficial effects from using baclofen for the treatment of alcohol dependence; however, limited conclusions can be drawn from the small number of studies currently available for review. Larger well-designed trials are needed to further define baclofen’s role for the treatment of alcohol dependence

Neutrino signals from electroweak bremsstrahlung in solar WIMP annihilation

Bremsstrahlung of $W$ and $Z$ gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced in processes such as $\chi\chi\rightarrow \bar{\nu}\nu Z$ and $\chi\chi\rightarrow \bar{\nu}\ell W$, and secondary neutrinos produced via the decays of gauge bosons and charged leptons. After dealing with the neutrino propagation and flavour evolution in the Sun, we consider the prospects for detection in neutrino experiments on Earth. By comparing our signal with that for annihilation to $W^+W^-$, we show that the detection prospects for the bremsstrahlung annihilation channel are favourable.Comment: 18 pages, 5 figures. Discussion expanded; matches published versio

Public attitudes towards privacy in COVID-19 times in the Republic of Ireland: a pilot study

This research focuses on designing methods aimed at assessing Irish public attitudes regarding privacy in COVID-19 times and their influence on the adoption of COVID-19 spread control technology such as the COVID tracker app. The success of such technologies is dependent on their adoption rate and privacy concerns may be a factor delaying or preventing thus adoption. An online questionnaire was built to collect: demographic data, participant's general privacy profile using the Privacy Segmentation Index (PSI) which classifies individuals into 3 groups (privacy fundamentalists, pragmatists, and unconcerned), and the attitudes toward privacy in COVID-19 times. The questionnaire was shared via websites and social networks. The data was collected between 27/08/2020 to 27/9/2020. We received and analysed 258 responses. The initial pilot study found that almost 73% of the respondents were pragmatists or unconcerned about privacy when it came to sharing their private data. Comparable results were obtained with other privacy studies that have employed PSI. The pilot indicates a huge increase, from 12% pre-pandemic to 61% during the pandemic, of people willing to share their data. The questionnaire developed following this study is further used in a national survey on privacy in COVID-19 times