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The deepwater oxygen deficit in stratified shallow seas is mediated by diapycnal mixing
Get PDFSeasonally stratified shelf seas are amongst the most biologically productive on the planet. A consequence is that the deeper waters can become oxygen deficient in late summer. Predictions suggest global warming will accelerate this deficiency. Here we integrate turbulence timeseries with vertical profiles of water column properties from a seasonal stratified shelf sea to estimate oxygen and biogeochemical fluxes. The profiles reveal a significant subsurface chlorophyll maximum and associated mid-water oxygen maximum. We show that the oxygen maximum supports both upward and downwards O2 fluxes. The upward flux is into the surface mixed layer, whilst the downward flux into the deep water will partially off-set the seasonal O2 deficit. The results indicate the fluxes are sensitive to both the water column structure and mixing rates implying the development of the seasonal O2 deficit is mediated by diapcynal mixing. Analysis of current shear indicate that the downward flux is supported by tidal mixing, whilst the upwards flux is dominated by wind driven near-inertial shear. Summer storminess therefore plays an important role in the development of the seasonal deep water O2 deficit
Parallel Adaptive Equalizer for Alamouti-Coded Signals Recovery in Simplified Coherent PON
Get PDFA simple single-polarization heterodyne optical network unit (ONU) receiver with Alamouti-coding based polarization diversity at the optical line terminal (OLT) side is a promising solution for passive optical networks (PON) beyond 50 Gbps. The special equalizer required for data recovery of such system has been demonstrated for 200 Gbps PON downstream using offline processing of serial data. In this letter, we extend such equalizer implementation with parallel processing that is required for real-time implementation. The proof-of-concept experiment for 200 Gbps downstream transmission is demonstrated to show the effectiveness of the proposed digital signal proccesing (DSP). The impact of phase noise and limitation of degree of parallelism are further investigated via numerical simulations
Selection on the joint actions of pairs leads to divergent adaptation and coadaptation of care-giving parents during pre-hatching care
Get PDFThe joint actions of animals in partnerships or social groups evolve under both natural selection from the wider environment and social selection imposed by other members of the pair or group. We used experimental evolution to investigate how jointly expressed actions evolve upon exposure to a new environmental challenge. Our work focused on the evolution of carrion nest preparation by pairs of burying beetles Nicrophorus vespilloides, a joint activity undertaken by the pair but typically led by the male. In previous work, we found that carrion nest preparation evolved to be faster in experimental populations without post-hatching care (No Care: NC lines) than with post-hatching care (Full Care: FC lines). Here, we investigate how this joint activity evolved. After 15 generations of experimental evolution, we created heterotypic pairs (NC females with FC males and NC males with FC females) and compared their carrion nest making with homotypic NC and FC pairs. We found that pairs with NC males prepared the nest more rapidly than pairs with FC males, regardless of the female's line of origin. We discuss how social coadaptations within pairs or groups could act as a post-mating barrier to gene flow. </p
Digital Remote Monitoring Using an mHealth Solution for Survivors of Cancer: Protocol for a Pilot Observational Study
Get PDFBACKGROUND: Healthy lifestyle interventions have a positive impact on multiple disease trajectories, including cancer-related outcomes. Specifically, appropriate habitual physical activity, adequate sleep, and a regular wholesome diet are of paramount importance for the wellness and supportive care of survivors of cancer. Mobile health (mHealth) apps have the potential to support novel tailored lifestyle interventions.OBJECTIVE: This observational pilot study aims to assess the feasibility of mHealth multidimensional longitudinal monitoring in survivors of cancer. The primary objective is to test the compliance (user engagement) with the monitoring solution. Secondary objectives include recording clinically relevant subjective and objective measures collected through the digital solution.METHODS: This is a monocentric pilot study taking place in Bangor, Wales, United Kingdom. We plan to enroll up to 100 adult survivors of cancer not receiving toxic anticancer treatment, who will provide self-reported behavioral data recorded via a dedicated app and validated questionnaires and objective data automatically collected by a paired smartwatch over 16 weeks. The participants will continue with their normal routine surveillance care for their cancer. The primary end point is feasibility (eg, mHealth monitoring acceptability). Composite secondary end points include clinically relevant patient-reported outcome measures (eg, the Edmonton Symptom Assessment System score) and objective physiological measures (eg, step counts). This trial received a favorable ethical review in May 2023 (Integrated Research Application System 301068).RESULTS: This study is part of an array of pilots within a European Union funded project, entitled "GATEKEEPER," conducted at different sites across Europe and covering various chronic diseases. Study accrual is anticipated to commence in January 2024 and continue until June 2024. It is hypothesized that mHealth monitoring will be feasible in survivors of cancer; specifically, at least 50% (50/100) of the participants will engage with the app at least once a week in 8 of the 16 study weeks.CONCLUSIONS: In a population with potentially complex clinical needs, this pilot study will test the feasibility of multidimensional remote monitoring of patient-reported outcomes and physiological parameters. Satisfactory compliance with the use of the app and smartwatch, whether confirmed or infirmed through this study, will be propaedeutic to the development of innovative mHealth interventions in survivors of cancer.INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/52957.</p
Optical injection effects in electrically pumped semiconductor nano-laser arrays
Get PDFA theoretical analysis is performed on the response of electrically pumped nano-laser arrays to external optical injection. The response to both continuous wave and modulated optical injection is explored. Continuous wave injection is shown to excite several varieties of dynamical behaviour in the array elements including regular dynamics and quasi-periodic behaviour. The strength of the optical injection, the frequency detuning between the injected light and the target laser, and the magnitude of the Purcell spontaneous emission enhancement factor are shown to markedly affect the dynamics. When subject to modulated optical injection, the effects of frequency detuning and optical injection strength are the focus of attention. It is shown that the elements of the array subject to modulated optical injection exhibit oscillatory behaviour over broad regimes determined by the optical injection strength and the frequency detuning
