Numerical optimisation in spot detector design

Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned with parameters. This paper addresses the problem of how to select the parameters. We propose to use carefully designed test images, a performance measure, and numerical optimisation techniques to solve this problem. Several optimisation methods are compared, and their adequacy for spot detector design is tested

Small variations in early-life environment can affect coping behaviour in response to foraging challenge in the three-spined stickleback

CONTEXT:An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change. STUDY DESIGN:This study on the three-spined stickleback (Gasterosteus aculeatus) is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400) were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds), and one year later offspring (F1, N = 652) were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water. FINDINGS:Our findings show that a) differences in early-life environment appear to affect stickleback feeding behaviour later in life; b) this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c) effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human-induced habitat disturbance may occur rapidly (within one generation) and vary strongly based on the system's (starting) conditions. This has important implications for the variability in animal behaviour, which may be much larger than expected from studying laboratory systems, as well as for the validity of predictions of population responses to change

SoftVoice improves speech recognition and reduces listening effort in cochlear implant users

Objectives:The ability to perceive soft speech by cochlear implant (CI) users is restricted in part by the inherent system noise produced by the speech processor, and in particular by the microphone(s). The algorithm "SoftVoice" (SV) was developed by Advanced Bionics to enhance the perception of soft speech by reducing the system noise in speech processors. The aim of this study was to examine the effects of SV on speech recognition and listening effort.Design:Seventeen adult Advanced Bionics CI recipients were recruited and tested in two sessions. The effect of SV on speech recognition was tested by determining the SRT in quiet using the Matrix test. Based on the individual subjects' SRTs, we investigated speech-recognition scores at fixed speech levels, namely SRT -5 dB, SRT +0 dB, SRT +5 dB, and SRT +10 dB, again in quiet and using the Matrix test. Listening effort was measured at each of these speech levels subjectively by using a rating scale, and objectively by determining pupil dilation with pupillometry. To verify whether SoftVoice had any negative effects on speech perception in noise, we determined the SRT in steady state, speech-weighted noise of 60 dBA.Results:Our results revealed a significant improvement of 2.0 dB on the SRT in quiet with SoftVoice. The average SRT in quiet without SoftVoice was 38 dBA. SoftVoice did not affect the SRT in steady state, speech-weighted noise of 60 dB. At an average speech level of 33 dBA (SRT -5 dB) and 38 dBA (SRT +0 dB) in quiet, significant improvements of 17% and 9% on speech-recognition scores were found with SoftVoice, respectively. At higher speech levels, SoftVoice did not significantly affect speech recognition. Pupillometry did not show significant effects of SoftVoice at any speech level. However, subjective ratings of listening effort indicated a decrease of listening effort with SoftVoice at a speech level of 33 dBA.Conclusions:We conclude that SoftVoice substantially improves recognition of soft speech and lowers subjective listening effort at low speech levels in quiet. However, no significant effect of SoftVoice was found on pupil dilation. As SRTs in noise were not statistically significantly affected by SoftVoice, we conclude that SoftVoice can be used in noisy listening conditions with little negative impact on speech recognition, if any. The increased power demands of the algorithm are considered to be negligible. It is expected that SoftVoice will reduce power consumption at low ambient sound levels. These results support the use of SoftVoice as a standard feature of Advanced Bionics CI fittings for everyday use.Disorders of the head and nec

Patterning and Conductivity Modulation of Conductive Polymers by UV Light Exposure

A novel patterning technique of conductive polymers produced by vapor phase polymerization is demonstrated. The method involves exposing an oxidant film to UV light which changes the local chemical environment of the oxidant and subsequently the polymerization kinetics. This procedure is used to control the conductivity in the conjugated polymer poly(3,4-ethylenedioxythiophene): tosylate by more than six orders of magnitude in addition to producing high-resolution patterns and optical gradients. The mechanism behind the modulation in the polymerization kinetics by UV light irradiation as well as the properties of the resulting polymer are investigated.Funding Agencies|Knut and Alice Wallenberg Foundation [KAW 2011.0050, KAW 2014.0041, KAW 2012.0302]</p

Interferentie door icodextrine bij POC-glucosemetingen

Een belangrijk deel van de dialysepatiënten verkiest peritoneaaldialyse boven hemo-dialyse. Bij een deel van de peritoneaaldialysepatiënten wordt icodextrine, een glucose-polymeer, als osmotisch agens aan de dialysevloeistof toegevoegd, omdat dit langer dan glucose een osmotische gradiënt over het peritoneum kan handhaven en derhalve een langere dialyseduur mogelijk maakt. Het blijkt echter dat een deel van het icodextrine via het lymfestelsel in de bloedbaan terechtkomt, waar het wordt gehydrolyseerd tot onder andere maltose en maltotriose. Deze glucose-oligomeren hopen zich op in het bloed en blijken in een aantal POC (point-of-care) glucosemeters aanleiding te geven tot significante overschattingen van de glucosewaarde met mogelijk dramatische gevolgen. Dit effect is voor een serie POC-glucosemeters bestudeerd, zowel door het bloed van peritoneaaldialysepatiënten te analyseren, als door in-vitro te kijken naar de kwantitatieve effecten van (commercieel) maltose en maltotriose: voornamelijk de POC-meters die gebruik maken van bacterieel geproduceerd glucosedehydrogenase lijken glucosespecificiteit te ontberen

Interferentie door icodextrine bij POC-glucosemetingen

Een belangrijk deel van de dialysepatiënten verkiest peritoneaaldialyse boven hemo-dialyse. Bij een deel van de peritoneaaldialysepatiënten wordt icodextrine, een glucose-polymeer, als osmotisch agens aan de dialysevloeistof toegevoegd, omdat dit langer dan glucose een osmotische gradiënt over het peritoneum kan handhaven en derhalve een langere dialyseduur mogelijk maakt. Het blijkt echter dat een deel van het icodextrine via het lymfestelsel in de bloedbaan terechtkomt, waar het wordt gehydrolyseerd tot onder andere maltose en maltotriose. Deze glucose-oligomeren hopen zich op in het bloed en blijken in een aantal POC (point-of-care) glucosemeters aanleiding te geven tot significante overschattingen van de glucosewaarde met mogelijk dramatische gevolgen. Dit effect is voor een serie POC-glucosemeters bestudeerd, zowel door het bloed van peritoneaaldialysepatiënten te analyseren, als door in-vitro te kijken naar de kwantitatieve effecten van (commercieel) maltose en maltotriose: voornamelijk de POC-meters die gebruik maken van bacterieel geproduceerd glucosedehydrogenase lijken glucosespecificiteit te ontberen

Resveratrol and Pterostilbene Inhibit SARS-CoV-2 Replication in Air-Liquid Interface Cultured Human Primary Bronchial Epithelial Cells

The current COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has an enormous impact on human health and economy. In search for therapeutic options, researchers have proposed resveratrol, a food supplement with known antiviral, anti-inflammatory, and antioxidant properties as an advantageous antiviral therapy for SARS-CoV-2 infection. Here, we provide evidence that both resveratrol and its metabolically more stable structural analog, pterostilbene, exhibit potent antiviral properties against SARS-CoV-2 in vitro. First, we show that resveratrol and pterostilbene antiviral activity in African green monkey kidney cells. Both compounds actively inhibit virus replication within infected cells as reduced virus progeny production was observed when the compound was added at post-inoculation conditions. Without replenishment of the compound, antiviral activity was observed up to roughly five rounds of replication, demonstrating the long-lasting effect of these compounds. Second, as the upper respiratory tract represents the initial site of SARS-CoV-2 replication, we also assessed antiviral activity in air–liquid interface (ALI) cultured human primary bronchial epithelial cells, isolated from healthy volunteers. Resveratrol and pterostilbene showed a strong antiviral effect in these cells up to 48 h post-infection. Collectively, our data indicate that resveratrol and pterostilbene are promising antiviral compounds to inhibit SARS-CoV-2 infection. Because these results represent laboratory findings in cells, we advocate evaluation of these compounds in clinical trials before statements are made whether these drugs are advantageous for COVID-19 treatment

Recurrence and survival after laparoscopy versus laparotomy without lymphadenectomy in early-stage endometrial cancer:Long-term outcomes of a randomised trial

Background: Laparoscopic hysterectomy is accepted worldwide as the standard treatment option for early-stage endometrial cancer. However, there are limited data on long-term survival, particularly when no lymphadenectomy is performed. We compared the survival outcomes of total laparoscopic hysterectomy (TLH) and total abdominal hysterectomy (TAH), both without lymphadenectomy, for early-stage endometrial cancer up to 5 years postoperatively. Methods: Follow-up of a multi-centre, randomised controlled trial comparing TLH and TAH, without routine lymphadenectomy, for women with stage I endometrial cancer. Enrolment was between 2007 and 2009 by 2:1 randomisation to TLH or TAH. Outcomes were disease-free survival (DFS), overall survival (OS), disease-specific survival (DSS), and primary site of recurrence. Multivariable Cox regression analyses were adjusted for age, stage, grade, and radiotherapy with adjusted hazard ratios (aHR) and 95% confidence intervals (95%CI) reported. To test for significance, non-inferiority margins were defined. Results: In total, 279 women underwent a surgical procedure, of whom 263 (94%) had follow-up data. For the TLH (n = 175) and TAH (n = 88) groups, DFS (90.3% vs 84.1%; aHR[recurrence], 0.69; 95%CI, 0.31–1.52), OS (89.2% vs 82.8%; aHR[death], 0.60; 95%CI, 0.30–1.19), and DSS (95.0% vs 89.8%; aHR[death], 0.62; 95%CI, 0.23–1.70) were reported at 5 years. At a 10% significance level, and with a non-inferiority margin of 0.20, the null hypothesis of inferiority was rejected for all three outcomes. There were no port-site or wound metastases, and local recurrence rates were comparable. Conclusion: Disease recurrence and 5-year survival rates were comparable between the TLH and TAH groups and comparable to studies with lymphadenectomy, supporting the widespread use of TLH without lymphadenectomy as the primary treatment for early-stage, low-grade endometrial cancer