Bottom-up and top-down effects of browning and warming on shallow lake food webs

Productivity and trophic structure of aquatic ecosystems result from a complex interplay of19 bottom-up and top-down forces that operate across benthic and pelagic food web compartments.20 Projected global changes urge the question how this interplay will be affected by browning21 (increasing input of terrestrial dissolved organic matter), nutrient enrichment and warming. We22 explored this with a process-based model of a shallow lake food web consisting of benthic and23 pelagic components (abiotic resources, primary producers, grazers, carnivores), and compared24 model expectations with the results of a browning and warming experiment in nutrient-poor25 ponds harboring a boreal lake community. Under low nutrient conditions, the model makes three26 major predictions. (1) Browning reduces light and increases nutrient supply; this decreases27 benthic and increases pelagic production, gradually shifting productivity from the benthic to the28 pelagic habitat. (2) Because of active habitat choice, fish exert top-down control on grazers and29 benefit primary producers primarily in the more productive of the two habitats. (3) Warming30 relaxes top-down control of grazers by fish and decreases primary producer biomass, but effects31 of warming are generally small compared to effects of browning and nutrient supply.32 Experimental results were consistent with most model predictions for browning: light penetration,33 benthic algal production, and zoobenthos biomass decreased, and pelagic nutrients and pelagic34 algal production increased with browning. Also consistent with expectations, warming had35 negative effects on benthic and pelagic algal biomass and weak effects on algal production and36 zoobenthos and zooplankton biomass. Inconsistent with expectations, browning had no effect on37 zooplankton and warming effects on fish depended on browning. The model is applicable also to38 nutrient-rich systems, and we propose that it is a useful tool for the exploration of the39 consequences of different climate change scenarios for productivity and food web dynamics in40 shallow lakes, the worldwide most common lake type.Fil: Rivera Vasconcelos, Francisco. Umea University. Department of Ecology and Environmental Science; SueciaFil: Diehl, Sebastian. Umea University. Department of Ecology and Environmental Science; SueciaFil: Rodriguez, Patricia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Hedström, Per. Umea University. Department of Ecology and Environmental Science; SueciaFil: Karlsson, Jan. Umea University. Department of Ecology and Environmental Science; SueciaFil: Byström, Pär. Umea University. Department of Ecology and Environmental Science; Sueci

Colorectal cancer treatment and early response evaluation, how do we best evaluate treatment response?

Colorectal cancer (CRC) is common, being responsible for around 12% of new cancers in Sweden, and contributing heavily to the large numbers of cancer deaths yearly. CRC is the second most common cause of cancer death not only in Sweden but also worldwide. In a large (n=567) multicentre, phase III study, the Nordic VI study, two different ways of giving 5-FU, bolus (FLv) and protracted infusion (Lv5FU2), together with irinotecan, in patients with metastatic (m)CRC was tested without any differences in progression-free survival (PFS) [9 months] or overall survival (OS) [19 months]. Fewer objective responses were seen in the FLIRI group (35% versus 49%, p = 0.001), but the metastatic resection rate did not differ (4% versus 6%, p = 0.3). In the same study a subset (n=51) of the population was evaluated for early metabolic treatment response with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). The mean baseline standard uptake value (SUV) for all tumor lesions per patient was higher in non-responders than in responders (mean 7.4 versus 5.6, p = 0.02). There was a strong correlation between metabolic response (changes in SUV) and objective response (p = 0.00001), with a sensitivity of 77% and a specificity of 76%. There was no significant correlation between metabolic response and PFS (P = 0.5) or OS (p = 0.1). In the Nordic VI study, selected tumor markers at baseline and during treatment were evaluated for their ability to predict response rate (RR), PFS and OS in two sub-studies. In the first one (n=90), low levels of tissue inhibitor of metallo-protease 1 (TIMP-1) levels at baseline were correlated to a higher probability of obtaining an objective response (P =0.007). Plasma TIMP-1scored as a continuous variable on a log scale (loge) was significantly associated with OS (P < 0.0001) and PFS (p =0.048).In the second sub-study (n=106) a significant correlation to OS was seen for baseline levels of all selected markers. In multivariate analyses with clinical parameters, TPA, CRP, SAA and TIMP-1 provided independent information. Changes during treatment, recorded as the slope gave with the exception of CA19-9 for OS less information about outcomes. The best correlation to response was seen for CEA, CA19-9 and TPA with AUC values of 0.78, 0.83 and 0.79, respectively, using a combined model based upon an interaction between the slope and the baseline value. Health related quality of life (HRQoL) was also evaluated in a subset of the Nordic VI population (n=220). There were no differences in HRQoL between the two treatment groups at any time point. Emotional functioning and pain improved, and diarrhea worsened with time. Most baseline QoL subscales correlated with OS. Independent information on OS, but not PFS or RR was seen for physical functioning (p=.000), appetite (p=.028) and constipation (p=.041) together with hemoglobin level. A summary score, based on the sum of all scale items, was independently related to OS (p=.000) and PFS (p=.006) but not to RR. Most patients with an objective tumor response or a long (≥ 4 months) disease stabilisation had a favourable HRQoL outcome; however, a minor portion did not. No significant correlations were seen between changes in QoL parameters during treatment and RR, PFS and OS

A corrector for wind power estimation and its usage in estimating icing losses

Upprättat; 2008; Bibliografisk uppgift: Homola, M.C., J. Byström, P.J. Nicklasson and P.A. Sundsbø (2008). A corrector for wind power estimation and its usage in estimating icing losses. Winterwind 2008, Norrköping, Sweden; 20110215 (johanb

The impact of corneal guttata on the results of cataract surgery

Purpose: To study the impact of corneal guttata on postoperative visual acuity and patients' self-assessed visual function after cataract surgery. Setting: Patient data from 49 Swedish cataract surgery units. Design: Retrospective cross-sectional register-based study. Methods: Data from patients who had cataract surgery from 2010 to 2017 and completed the Catquest-9SF questionnaire were obtained from the Swedish National Cataract Register. Logistic proportional odds regression was used to model the impact of corneal guttata on the visual acuity and self-assessed visual function. Adjustments were made for age, sex, ocular comorbidities, days to follow-up, preoperative corrected distance visual acuity (CDVA) and preoperative Rasch person score. The main outcome measures were postoperative CDVA and Rasch person score calculated from the Catquest-9SF questionnaire. Results: The study comprised data from 33 741 patients. Cataract surgery greatly improved CDVA and self-assessed visual function in patients both with and without corneal guttata. Still, corneal guttata was significantly associated with a poorer visual acuity and a worse self-assessed visual function after cataract surgery. The negative effect of corneal guttata on visual acuity was most prominent during the first 3 weeks postoperatively, but it persisted at least 3 months postoperatively. Conclusions: Patients with corneal guttata benefit substantially from cataract surgery but have an additional risk for inferior results compared with patients without corneal guttata. These findings could serve as valuable tools in clinical practice, in particular, when deciding to perform cataract surgery and how to inform the patient about surgical benefits and risks.Reply: Viberg, Andreas MD; Liv, Per PhD; Behndig, Anders MD, PhD; Lundström, Mats MD, PhD; Byström, Berit MD, PhD Impact of corneal guttata on cataract surgery results, Journal of Cataract &amp; Refractive Surgery: November 2019 - Volume 45 - Issue 11 - p 1692-1693 doi: 10.1016/j.jcrs.2019.08.049</p

Attack rate (l s⁻¹±1SE) of char (obtained from [31]) and ninespine stickleback when feeding on zooplankton (<i>Daphnia sp.</i>).

<p>Attack rate (l s⁻¹±1SE) of char (obtained from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070404#pone.0070404-Bystrm4" target="_blank">[31]</a>) and ninespine stickleback when feeding on zooplankton (<i>Daphnia sp.</i>).</p

Summary of conducted predation experiments of Arctic char feeding on char and sticklebacks, showing; number of replicates for treatments with predators and controls for background mortality, number of piscivorous char used per enclosure, numbers and density of prey species introduced, mean predator and prey sizes ±1 SD, duration of experiments, time (month) when experiments were conducted, average temperature based on mean of start and end temperatures of experiments.

<p>Average temperature is not available for experiment 3.</p