Modulated Backscatter for Low-Power High-Bandwidth Communication

<p>This thesis re-examines the physical layer of a communication link in order to increase the energy efficiency of a remote device or sensor. Backscatter modulation allows a remote device to wirelessly telemeter information without operating a traditional transceiver. Instead, a backscatter device leverages a carrier transmitted by an access point or base station.</p><p>A low-power multi-state vector backscatter modulation technique is presented where quadrature amplitude modulation (QAM) signalling is generated without running a traditional transceiver. Backscatter QAM allows for significant power savings compared to traditional wireless communication schemes. For example, a device presented in this thesis that implements 16-QAM backscatter modulation is capable of streaming data at 96 Mbps with a radio communication efficiency of 15.5 pJ/bit. This is over 100x lower energy per bit than WiFi (IEEE 802.11).</p><p>This work could lead to a new class of high-bandwidth sensors or implantables with power consumption far lower than traditional radios.</p>Dissertatio

A gender perspective on entrepreneurial leadership:female leaders in Kazakhstan

The paper proposes a conceptual model to understand female entrepreneurial leadership through an exploration of the perceptions and experiences of women entrepreneurs within their leadership roles. The paper addresses an existing knowledge gap on entrepreneurial leadership by bringing together three key constructs of gender, leadership and entrepreneurship. We apply Stewart's model of role demands-constraints-choices (DCC) to women entrepreneurs in Kazakhstan in order to understand their perceptions of the demands, constraints and choices they experience within their leadership roles. The results of in-depth interviews with women entrepreneurs present deeper conceptualization of their leadership enactment as a co-developing, co-constructed relational activity between leaders and others in their wider business environments and context

Aptamer-based multiplexed proteomic technology for biomarker discovery

Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Does home oxygen therapy (HOT) in addition to standard care reduce disease severity and improve symptoms in people with chronic heart failure? A randomised trial of home oxygen therapy for patients with chronic heart failure

Background: Home oxygen therapy (HOT) is commonly used for patients with severe chronic heart failure(CHF) who have intractable breathlessness. There is no trial evidence to support its use.Objectives: To detect whether or not there was a quality-of-life benefit from HOT given as long-termoxygen therapy (LTOT) for at least 15 hours per day in the home, including overnight hours, comparedwith best medical therapy (BMT) in patients with severely symptomatic CHF.Design: A pragmatic, two-arm, randomised controlled trial recruiting patients with severe CHF. It includeda linked qualitative substudy to assess the views of patients using home oxygen, and a free-standingsubstudy to assess the haemodynamic effects of acute oxygen administration.Setting: Heart failure outpatient clinics in hospital or the community, in a range of urban andrural settings.Participants: Patients had to have heart failure from any aetiology, New York Heart Association (NYHA)class III/IV symptoms, at least moderate left ventricular systolic dysfunction, and be receiving maximallytolerated medical management. Patients were excluded if they had had a cardiac resynchronisation therapydevice implanted within the past 3 months, chronic obstructive pulmonary disease fulfilling the criteria forLTOT or malignant disease that would impair survival or were using a device or medication that wouldimpede their ability to use LTOT.Interventions: Patients received BMT and were randomised (unblinded) to open-label LTOT, prescribed for15 hours per day including overnight hours, or no oxygen therapy.Main outcome measures: The primary end point was quality of life as measured by the Minnesota Livingwith Heart Failure (MLwHF) questionnaire score at 6 months. Secondary outcomes included assessing theeffect of LTOT on patient symptoms and disease severity, and assessing its acceptability to patientsand carers.Results: Between April 2012 and February 2014, 114 patients were randomised to receive either LTOT orBMT. The mean age was 72.3 years [standard deviation (SD) 11.3 years] and 70% were male. Ischaemicheart disease was the cause of heart failure in 84%; 95% were in NYHA class III; the mean left ventricularejection fraction was 27.8%; and the median N-terminal pro-B-type natriuretic hormone was 2203 ng/l.The primary analysis used a covariance pattern mixed model which included patients only if they provided datafor all baseline covariates adjusted for in the model and outcome data for at least one post-randomisationtime point (n = 102: intervention, n = 51; control, n = 51). There was no difference in the MLwHF questionnairescore at 6 months between the two arms [at baseline the mean score was 54.0 (SD 18.4) for LTOT and54.0 (SD 17.9) for BMT; at 6 months the mean score was 48.1 (SD 18.5) for LTOT and 49.0 (SD 20.2) forBMT; adjusted mean difference –0.10, 95% confidence interval (CI) –6.88 to 6.69; p = 0.98]. At 3 months,the adjusted mean MLwHF questionnaire score was lower in the LTOT group (–5.47, 95% CI –10.54 to–0.41; p = 0.03) and breathlessness scores improved, although the effect did not persist to 6 months.There was no effect of LTOT on any secondary measure. There was a greater number of deaths in the BMTarm (n = 12 vs. n = 6). Adherence was poor, with only 11% of patients reporting using the oxygenas prescribed.Conclusions: Although the study was significantly underpowered, HOT prescribed for 15 hours per dayand subsequently used for a mean of 5.4 hours per day has no impact on quality of life as measured bythe MLwHF questionnaire score at 6 months. Suggestions for future research include (1) a trial of patientswith severe heart failure randomised to have emergency oxygen supply in the house, supplied by cylindersrather than an oxygen concentrator, powered to detect a reduction in admissions to hospital, and (2) astudy of bed-bound patients with heart failure who are in the last few weeks of life, powered to detectchanges in symptom severity.Trial registration: Current Controlled Trials ISRCTN60260702.Funding: This project was funded by the NIHR Health Technology Assessment programme and will bepublished in full in Health Technology Assessment; Vol. 19, No. 75. See the NIHR Journals Library websitefor further project information

Proceedings of Patient Reported Outcome Measure’s (PROMs) Conference Oxford 2017: Advances in Patient Reported Outcomes Research

A33-Effects of Out-of-Pocket (OOP) Payments and Financial Distress on Quality of Life (QoL) of People with Parkinson’s (PwP) and their Carer

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11–1.70] ng/mL vs 0.24 [0.10–0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51–.60]).</jats:p