AWG-DBR-based WDM transmitter fabricated in an InP generic foundry platform

We report a novel narrow-linewidth WDM transmitter operating at 10 Gbps per transmission channel with 275 kHz optical linewidth. The device, which integrates an AWG-based laser using selective DBR-mirrors with a Mach-Zehnder modulator array, has been fabricated in a multi-project wafer run in a generic InP-based foundry process.</p

Athermal colorless C-band optical transmitter system for passive optical networks

This paper reports an uncooled transmitter system using a digital super-mode (DS) distributed Bragg reflector (DBR) tunable laser, which is able to act as an athermal, wavelength agnostic transmitter suitable for wavelength division multiplexed (WDM) passive optical network (PON) applications. An open-loop laser current control algorithm is designed to compensate autonomously for wavelength drift, thus allowing constant operating wavelength to be achieved regardless of ambient temperature. An improved wavelength accuracy of ±3 GHz is achieved when using low bandwidth feedback from the central office using information from a centralized shared wavelength locker. The entire laser start-up, channel selection and subsequent wavelength control is autonomous and has been implemented on micro-controllers and field programmable gate arrays. We demonstrate a three channel WDM-PON system comprising an uncooled packaged DS-DBR laser in the presence of two neighboring interfering channels. Error free transmission over 40 km single mode fiber of 10 Gb/s externally modulated NRZ data, is achieved for each of 48 C-band channels on the 100 GHz ITU grid. Successful athermal operation is demonstrated by sweeping the ambient temperature of the laser from 15 to 70 °C with a maximum wavelength deviation for any channel of no more than 0.1 nm.This work has been supported by the Technology Strategy Board, UK and by the German ministry for education and research, through the EU ERA-NET+ projects PIANO+ IMPACT (BMBF grant: 13N11434) and TUCAN (BMBF grant: 13N11573). We also acknowledge the support of the UK Engineering and Physical Sciences Research Council via the INTERNET project.This is the final version of the article. It first appeared from IEEE via http://dx.doi.org/10.1109/JLT.2014.235405

Multiphysics simulation tools for designing motors for traction applications in hybrid and electric vehicles

Motor manufacturers are facing a difficult challenge in designing traction motors for the latest generation of hybrid and all-electric vehicles. The efficiency with which these motors can perform is critical, as it impacts on the vehicle range and battery life. Many of the issues involved in the motor design have a complex nature which requires multiple fields of physics such as electromagnetics (EM), mechanics and thermal analysis. All these physics are usually interdependent and have to be considered collectively in order to obtain optimal performance for a particular scenario. This paper presents a multiphysics simulation tool that was implemented to address this situation. The Opera FEA software suite [1] was developed to include a multiphysics analysis that can link several EM, thermal and stress analyses. Opera’s Machines Environment (parameterised template software for designing motors and generators) has been extended to allow easy setup of coupled multiphysics analyses such as EM to thermal and EM to stress. In order to further facilitate the coupling of different analyses, a link to the Python programming language was embedded in Opera FEA software. The embedded Python facility offers options to perform certain post-processing operations during the solving stage and hence allow data transfer between different stages of the multiphysics analysis. It also extends Opera’s capabilities to interact with other FEA software

Field demonstration of a tunable WDM-PON system with novel SFP+ modules and centralized wavelength control

We report on a demonstration of a novel tunable WDM-PON system over 25km of field deployed fiber. We show error-free operation at 1 GbE with sensitivity better than -30dBm and centralized control of the ONU wavelengths.This work has been supported by the EU ERA-NET+ projects PIANO+ IMPACT and PIANO+ TUCAN co-funded by the German BMBF, the UK Technology Strategy Board and the Austrian FFG. Also support from the UK EPSRC INTERNET project is acknowledged.This is the author accepted manuscript. The final version is available from OAS Publishing via http://dx.doi.org/10.1364/OFC.2015.M2A.

Evaluation of andrological indices and testicular histology following administration of varied doses of nicotine

This study is aimed at determining the effect of Nicotine on male fertility by evaluating some andrological parameters of male Wistar rat such as sperm parameters (spermatozoa count and motility), serum concentration of testosterone and testicular weight. Histopathology of the testis was also carried out on the effect of nicotine on testicular microstructure. 20 adult male rats were randomly divided into four groups, the test groups were administered with 0.2mg/100g, 0.4/100g and 0.6/100g body weight daily for 30 days while the control were administered with 2mls 0.9% physiological saline. Nicotine caused a significant reduction (P &lt; 0.05) and (P&lt; 0.01) in the mean values of sperm count, serum testosterone concentration and testicular weight in the test when compared with the control. Also, in the test group, the deleterious effect of nicotine on the sperm parameters and testosterone concentration was corroborated by histopathology which revealed a marked degeneration of germ cell layers in the seminiferous tubule and disruption of interstitial cells of the testis thereby interfering with spermatogenesis and testosterone secretion while there was no visible change in the control group. It was concluded that nicotine exerted toxic effect on the germ cell layers in seminiferous tubule with concomitant reduction in reproductive potentials of the male rat whilst showing no significant change in sperm motility. Nicotine and nicotine based products should therefore be taken with caution in cases of infertility. Key words: germ cells, testes, testosterone, fertility, spermatogenesis

Resuscitation with pre-hospital blood products in adults with trauma-related haemorrhagic shock:the RePHILL RCT

Background: The treatment of traumatic haemorrhagic shock has been transformed through better haemorrhage control, use of tranexamic acid and use of blood products. The improved survival seen from these strategies has stimulated an interest in pre-hospital transfusion.Objectives: To determine if the clinical effectiveness of resuscitation with red blood cells and lyophilised plasma was superior to 0.9% saline for improving tissue perfusion and reducing mortality in adults with haemorrhagic shock following major trauma.Design: A multi-centre, allocation concealed, open-label, parallel group, randomised controlled trial (with internal pilot).Setting: The trial was conducted in four civilian pre-hospital critical care services who operated within the National Health Service (NHS) England Major Trauma Networks.Participants: Adults (aged ≥16 years) who had sustained traumatic injuries, were attended by a pre-hospital emergency medical team and were hypotensive (systolic blood pressure &lt;90 mmHg or absence of radial pulse) as a consequence of traumatic haemorrhage were eligible for inclusion. The exclusion criteria were known or apparently &lt;16 years, blood administered on scene prior to the arrival of the RePHILL team, traumatic cardiac arrest where (1) the arrest occurred prior to arrival of the team and/or (2) the primary cause is not hypovolaemia, refusal of blood product administration, known Jehovah’s Witness, pregnancy, isolated head injury without evidence of external haemorrhage, prisoners in the custody of HM Prison and Probation Service.Interventions: Participants were randomised to receive up to either two units each of red blood cells and lyophilised plasma or up to 1 L 0.9% saline. Treatment was administered through the intravenous or intraosseous route.Main outcome measures: The primary outcome was a composite of episode mortality and/or impaired lactate clearance. The secondary outcomes included the individual components of the primary outcome.Results: From 6 December 2016 to 2 January 2021, pre-hospital medical teams randomised 432 participants to red blood cell/lyophilised plasma (n = 209) or 0.9% saline (n = 223) out of a target sample size of 490. Most participants were white (62%), males (82%), median age 38 (interquartile range 26 to 58), involved in a road traffic collision (62%) with severe injuries (median injury severity score 36, interquartile range 25 to 50). Prior to randomisation participants had received on average 430 ml crystalloid fluids and tranexamic acid (90%). The primary outcome occurred in 128/199 (64.3%) of participants randomised to red blood cell/lyophilised plasma and 136/210 (64.8%) randomised to 0.9% saline [adjusted risk difference –0.025% (95% confidence interval –9.0% to 9.0%), p = 0.996]. The event rates for the individual components of the primary outcome, episode mortality and lactate clearance were not statistically different between groups [adjusted average differences −3% (−12% to 7%); p = 0.57 and −5% (−14% to 5%), p = 0.33, respectively].Limitations: Recruitment stopped prematurely due to disruption caused by the COVID-19 pandemic.Future work: Identify the characteristics of patients who may benefit from pre-hospital blood products and whether alternative transfusion regimens are superior to standard care.Conclusions: The trial did not demonstrate that pre-hospital red blood cell/lyophilised plasma resuscitation was superior to 0.9% saline for trauma-related haemorrhagic shock.Trial registration: This trial is registered as ISRCTN62326938.Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (NIHR award ref: 14/152/14) and is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 2. See the NIHR Funding and Awards website for further award information.<br/

Randomised Controlled Trial of Particles Used in Uterine fibRoid Embolisation (PURE): Non-Spherical Polyvinyl Alcohol Versus Calibrated Microspheres.

PURPOSE: The PURE study is a randomised controlled trial (RCT) comparing the clinical and MRI outcomes of patients treated with non-spherical polyvinyl alcohol, ns-PVA (Contour PVA-Boston Scientific-355-500 & 500-700 microns) versus calibrated hydrogel microspheres (Embozene-Varian Inc-700 & 900 microns) for symptomatic uterine fibroids. MATERIALS AND METHODS: Prospective, ethically approved non-sponsored RCT in 84 patients in a single UK tertiary IR unit, ISRCTN registry trial number ISRCTN18191539 in 2013 and 2014. All patients with symptomatic fibroid disease were eligible. UAE followed a standardised protocol with UFS-QOL and contrast-enhanced MRI before and 6 months post UAE. Outcome measures included: (1) Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL). (2) Percentage total and dominant fibroid infarction. (3) Uterine and dominant fibroid volume reduction. (4) Volume of embolics. RESULTS: Sixty-three patients completed the QOL follow-up (33 ns-PVA vs 30 Embozenes), the groups were equivalent at baseline. Patients were followed up for 6 months following UAE. There was no significant difference in symptom scores or HR-QOL between ns-PVA and Embozenes, p = 0.67 and 0.21, respectively. 92.7% of patients treated with ns-PVA achieved > 90% dominant fibroid infarction versus 61.8% treated with Embozenes (p = 0.0016). 66% of patients treated with ns = PVA achieved > 90% total fibroid percentage infarction compared with 35% in the Embozene group (p = 0.011). The mean vials/syringes used were 5.2 with Embozenes versus 4.1 using PVA (p = 0.08). CONCLUSION: The PURE study informs IRs regarding the efficacy of embolic agents in UAE, with superior fibroid infarction on MRI using ns-PVA versus Embozenes however no significant difference in clinical outcomes at 6 months after UAE

Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.

types: Journal ArticleCopyright: © 2014 Voellmy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic) factors can influence predator-prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour), compared with control conditions (playback of recordings from the same harbours without ship noise), affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus) and the European minnow (Phoxinus phoxinus), which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.University of BristolBasler Stiftung für Biologische ForschungDefr

Acoustic risk balancing by marine mammals : anthropogenic noise can influence the foraging decisions by seals

Funding: Natural Environment Research Council (Grant Number(s): NE/J004251/1, NE/R015007/1)1. Avoidance of anthropogenic sounds has been measured in many species. The results, which are typically based on observations in limited exposure contexts, are frequently used to inform policy and the regulation of industrial activities. However, the occurrence and magnitude of avoidance may be a consequence of complex risk-balancing decisions made by animals. The importance of the factors in decision-making, such as perceived risks associated with the sounds or prey quantity and quality during sound exposure, is unknown. 2. Here we address this knowledge gap by measuring the relative influence of perceived –risk of a sound (silence, pile driving, and a tidal turbine) and prey patch quality on decision-making and foraging success in grey seals Halichoerus grypus. 3. Seals were given access to two underwater ‘prey patches’ in an experimental pool where fish were delivered at controlled rates to simulate a low-density (LD) and a high-density (HD) prey patch. Acoustic playbacks were made using an underwater speaker above one of the prey patches (randomised during the study), and three decision and foraging metrics (foraging duration, foraging effort allocation between the prey patches, and foraging success) were measured. 4. Foraging success was highest during silent controls and was similar regardless of speaker location (LD/HD). Under the tidal turbine and pile-driving treatments, foraging success was similar to the controls when the speaker was located at the HD prey patch but was significantly reduced (~16%–28% lower) when the speaker was located at the LD prey patch. Foraging decisions by the seals were consistent with a risk/profit balancing approach. Avoidance rates depend on the quality of the prey patch as well as the perceived risk. 5. Policy implications. The results suggest that foraging context is important when interpreting avoidance behaviour and should be considered when predicting the effects of anthropogenic activities. For example, sound exposure in different prey patch qualities may result in markedly different avoidance behaviour, potentially leading to contrasting predictions of impact in Environmental Assessments. We recommend future studies explicitly consider foraging context, and other contextual factors such as behavioural state (e.g. foraging or travelling) and habitat quality.Publisher PDFPeer reviewe