RF phase sensitive amplifier with 70 dB phase sensitive dynamic range

© 2018 In this paper, a novel microwave photonic phase sensitive amplifier is proposed and demonstrated. A theoretical model is developed and compared to the results obtained from a simulation. Using efficient mixing in second order nonlinear materials such as periodically poled lithium niobate, the resultant amplifier exhibits over 70dB of phase dependent gain variation. This RF phase sensitivity can be used to reduce phase noise and therefore finds applications in PSK phase regeneration and phase noise reduction

Optimal rate adaptation for energy efficiency with MQAM and MFSK

© 2014 National Institute of Information and Communicatio. In this paper we analyse the energy efficiency of MQAM and MFSK for short range wireless transmissions, up to a few 100's of meters, and propose optimum rate adaptation to minimize the energy dissipation during transmissions under different channel environment. Energy consumed for transmitting the data over a distance to maintain a prescribed error probability together with the circuit energy have been considered in our work. Our results indicate that the energy efficiency can be significantly improved by performing optimal rate adaptation given the radio and channel parameters, and furthermore we identify the maximum distance where optimal rate adaptation can be performed beyond which the optimum rate then becomes the same as the minimum data rate

Energy efficiency of cellular base stations with ternary-state transceivers

The energy efficiency of cellular base stations is known to be improved by having the base station in sleep modes whenever possible. In this paper we present our study on ternary state transceivers for cellular base stations for further improving the energy efficiency. We consider transceivers that are capable of switching between sleep, stand-by and active modes whenever required. the ternary state transceiver is modeled as a three-state Markov process and we present an algorithm to intelligently change the states of the transceivers based on the offered traffic to the base station whilst maintaining a prescribed minimum rate per user. We present simulation results considering a typical macro base station with state changeable transceivers. Our results show that it is possible to significantly improve the energy efficiency of the base station using the proposed algorithm and further show that the algorithm approaches steady state conditions for the range of parametric values that we consider in our study. © 2015 IEEE

Community pharmacists’ role in preventing opioid substitution therapy-related deaths: a qualitative investigation into current UK practice

© 2019, The Author(s). Background Opioid substitution therapy involves prescribing of medical substitutes like methadone and buprenorphine to patients who are addicted to opioids. The majority of opioid substitution therapy dispensing in the UK is done by community pharmacists and they often see the patients on daily basis. It is unknown to what extent community pharmacists implement the policy to prevent overdose in patients receiving such treatment. Objective To explore what UK community pharmacists think about their role in preventing opium substitution-related deaths, their understanding of the risks associated with this substitution therapy and their views on what else community pharmacists could do to reduce such deaths. Setting Twenty four community pharmacists from two areas in UK (Worcestershire and Bath and North East Somerset). Method Between January and March 2013, community pharmacists providing opoin substitution therapy were interviewed in their pharmacy, using semi-structured interviews. Interpretative Phenomenology Analysis was used to analyse the data. Main outcome measure Thematically organised description of professional practice as reported by the participants against the clinical/practice guidance for opioid substitution therapy in UK. Results While participants felt their role to be essential in providing the service, they did not feel part of an integrated system. Participants’ ability to act in risk situations was affected by their knowledge, confidence in intervening in such situation, as well as the support they receive in providing the service. Conclusion Participants reported large differences in how ‘opioid substitution therapy’ services are provided in community pharmacy. Lack of knowledge among some pharmacists and lack of support in providing the service resulted in some patients at high risk not having their risks acted upon

An MDP-based energy efficient and delay aware handover algorithm

This paper presents a novel energy efficient and delay aware handover decision policy based on Markov decision process (MDP) for a two-tier (macro-femto) wireless network. We propose a novel reward function and formulate a novel transition probability matrix to be used in MDP in order to take optimal handover decision. Simulation results reveal that, compared to other competitive handover policies, the proposed policy can significantly reduce the power consumption as well as handover delay at the mobile terminals

Energy efficient and delay aware ternary-state transceivers for aerial base stations

In recent times, Aerial Base Stations(AeBSs) are being investigated to provide wireless coverage to terrestrial radio terminals. There are many advantages of using aerial platforms to provide wireless coverage, including larger coverage in remote areas and better line-of-sight conditions, etc. Energy is a scarce resource for the AeBSs, hence the wise management of energy is quite beneficial for the aerial network. In this context, we study the means of reducing the total energy consumption by designing and implementing an energy efficient AeBSs as presented in this paper. Implementing the sleep mode in the Base Stations (BSs) has been proven to be a very good approach for improving the energy efficiency and we propose a novel strategy for further improving energy efficiency by considering ternary state transceivers for AeBSs. Using the three state model, we propose a Markov Decision Process (MDP) based algorithm, which intelligently switches among three states of the transceivers based on the offered traffic meanwhile maintaining a prescribed minimum channel rate per user. We define a reward function for the MDP, which helps us to get an optimal policy for selecting a particular mode for the transceivers of the AeBS. Considering an AeBS with transceivers whose states are changeable, we perform simulations to analyse the performance of the algorithm. Our results show that, compared with the always active model, around 40% gain in the energy efficiency is achieved by using our proposed MDP algorithm together with the three-state transceivers model. We also show the energy-delay tradeoff in order to design an efficient AeBS. © 2018 Chongqing University of Posts and Telecommunication

Think sociology

With an engaging visual design and just 15 chapters, THINK Sociology is the Australian Sociology text your students will want to read. This text thinks their thoughts, speaks their language, grapples with the current-day problems they face, and grounds sociology in real world experiences

A quantitative assessment of termination of sexual violence-related pregnancies in eastern Democratic Republic of Congo.

BACKGROUND: Sexual violence is prevalent in eastern Democratic Republic of Congo (DRC), and has resulted in sexual violence-related pregnancies (SVRPs). Despite restrictive laws, women may seek to terminate SVRPs; however, there are limited data on termination of SVRPs. METHODS: A mixed methods study was conducted in 2012 in Bukavu, DRC. Adult women who self-reported an SVRP and termination of that SVRP were recruited using respondent-driven sampling (RDS). Trained female interviewers verbally administered a quantitative survey to all participants and a semi-structured qualitative survey to a subset. Quantitative data on characteristics and complications of pregnancy termination, including mental health outcomes, were analyzed using SAS. RESULTS: In total, 86 women completed quantitative surveys. Most SVRPs (93 %) involved two or more assailants; 73 % occurred while in captivity. Most women (82 %) terminated the SVRPs at 3 months gestation or earlier; 79 % reported one attempt at pregnancy termination and 21 % more than one attempt. The most common methods of termination were an oral medicine (55 %) or herb (35 %); cimpokolo (31 %) and quinine (18 %) were most frequently reported. These methods were accessed through friends (37 %), healthcare providers (18 %), family (16 %), or self-obtained (12 %). Following the termination, 79 % of women reported subsequent physical symptoms, including abdominal pain (74 %), bleeding (47 %), vaginal discharge (35 %) and fever (18 %); 44 % sought medical care for their symptoms. Varied emotional responses to the termination were reported and included relief (34 %), anxiety (21 %), anger (19 %), guilt (19 %), and regret (10 %). At the time of the study, many women met symptom criteria for post-traumatic stress disorder (57 %), depression (50 %), and generalized anxiety disorder (33 %). CONCLUSION: Most women terminated SVRPs using medications or herbs not recognized as evidence-based methods of pregnancy termination and sought these methods outside of the formal healthcare sector. These data suggest that access to safe abortion methods is needed for women with SVRPs in DRC. Physical symptoms and emotional reactions related to the termination varied. While it is not possible to differentiate the impacts of sexual violence, SVRP, and pregnancy termination on mental health outcomes, the findings highlight the complex needs of women with SVRPs and opportunities for integrative health services

A cross-sectional exploration of the clinical characteristics of disengaged (NEET) young people in primary mental healthcare

Objective: Youth with mental health problems often have difficulties engaging in education and employment. In Australia, youth mental health services have been widely established with a key aim of improving role functioning; however, there is little knowledge of those who are not engaged in employment, education or training (NEET) and the factors which may influence this. This study aimed to examine NEET status and its correlates in a sample of such youth. Design: Cross-sectional data from a longitudinal cohort study. Setting: Between January 2011 and August 2012, young people presenting to one of the four primary mental health centres in Sydney or Melbourne were invited to participate. Participants: Young adults (N=696) aged between 15 and 25 years (M=19.0, SD=2.8), 68% female, 58% (n=404) attended headspace in Sydney. Measures: Individuals 'Not in any type of Education, Employment or Training' in the past month were categorised as NEET. Demographic, psychological and clinical factors alongside disability and functioning were assessed using clinical interview and self-report. Results: A total of 19% (n=130/696) were NEET. NEETs were more likely to be male, older, have a history of criminal charges, risky cannabis use, higher level of depression, poorer social functioning, greater disability and economic hardship, and a more advanced stage of mental illness than those engaged in education, training or work. Demographics such as postsecondary education, immigrant background and indigenous background, were not significantly associated with NEET status in this sample. Conclusions: One in five young people seeking help for mental health problems were not in any form of education, employment and training. The commonly observed risk factors did not appear to influence this association, instead, behavioural factors such as criminal offending and cannabis use appeared to require targeted intervention

Preventing depression in final year secondary students: School-based randomized controlled trial

Background: Depression often emerges for the first time during adolescence. There is accumulating evidence that universal depression prevention programs may have the capacity to reduce the impact of depression when delivered in the school environment. Objective: This trial investigated the effectiveness of SPARX-R, a gamified online cognitive behavior therapy intervention for the prevention of depression relative to an attention-matched control intervention delivered to students prior to facing a significant stressor-final secondary school exams. It was hypothesized that delivering a prevention intervention in advance of a stressor would reduce depressive symptoms relative to the control group. Methods: A cluster randomized controlled trial was conducted in 10 government schools in Sydney, Australia. Participants were 540 final year secondary students (mean 16.7 [SD 0.51] years), and clusters at the school level were randomly allocated to SPARX-R or the control intervention. Interventions were delivered weekly in 7 modules, each taking approximately 20 to 30 minutes to complete. The primary outcome was symptoms of depression as measured by the Major Depression Inventory. Intention-to-treat analyses were performed. Results: Compared to controls, participants in the SPARX-R condition (n=242) showed significantly reduced depression symptoms relative to the control (n=298) at post-intervention (Cohen d=0.29) and 6 months post-baseline (d=0.21) but not at 18 months post-baseline (d=0.33). Conclusions: This is the first trial to demonstrate a preventive effect on depressive symptoms prior to a significant and universal stressor in adolescents. It demonstrates that an online intervention delivered in advance of a stressful experience can reduce the impact of such an event on the potential development or exacerbation of depression