Powdery mildew of cucumber – causal agents, disease management and introduction of a web application for disease assessment

Der Echte Mehltau an Cucurbitaceen ist weltweit verbreitet. In Europa treten als Erreger im Wesentlichen zwei Arten auf, Podosphaera xanthii (syn. Sphaerotheca fuliginea, S. fusca) und Golovinomyces orontii (syn. Erysiphe cichoracearum). Im vorliegenden Beitrag wird der Stand der Forschung zur Bekämpfung des Gurkenmehltaus mit alternativen Agenzien wie Salzen, Mikroorganismen und anderen Naturstoffen anhand der Literatur kurz beschrieben. Weiterhin wird ein Überblick über die Möglichkeiten zur Regulierung des Gurkenmehltaus in der Praxis gegeben. Im letzten Teil wird eine neue Internetanwendung zur Befallsschätzung des Echten Mehltaus auf Gurkenblättern vorgestellt. Sie ermöglicht das Erlernen des Schätzens des Befalls in drei Gruppen: geringer (bis 15%), mittlerer (10–40%) und stärkerer Befall (mehr als 30%) anhand zufällig ausgewählter Befallsbilder. Des Weiteren kann ein Verlauf der Krankheit angedeutet werden, indem die 67 einzeln konstruierten Befallsbilder nacheinander wie ein Film ablaufen. Die Webanwendung für Gurkenmehltau ergänzt zehn bereits vorhandene, gleichartige Webanwendungen zur Befallsschätzung wichtiger Getreidekrankheiten. Die Webanwendungen sind im Internet über die URL http://prozentualer-befall.jki.bund aufrufbar.Powdery mildew of cucurbits is distributed worldwide. In Europe, the disease is mainly caused by the two species Podosphaera xanthii (syn. Sphaerotheca fuliginea, S. fusca) and Golovinomyces orontii (syn. Erysiphe cichoracearum). In this contribution, the current state of research on alternative agents for control of cucumber powdery mildew like salts, microorganisms and other agents of natural origin is shortly reviewed. In addition, an overview is given on measures available for regulation of cucumber powdery mildew in practical horticulture. Finally, a new web application for assessment of powdery mildew on cucumber leaves is introduced. It facilitates the training of disease assessment by random presentation of 67 computer-constructed drawings belonging to one of three classes, low (up to 15%), medium (10–40%) and high (more than 30%) disease severity. Furthermore, the disease progress can be simulated by presenting a film-like sequence of the 67 computer-constructed drawings in the order of increasing disease severity. The web application for powdery mildew of cucumber is presented under the URL http://prozentualer-befall.jki.bund.de, together with ten already existing equivalent schemes for cereal diseases

Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in Kongsfjorden on the west coast of Spitsbergen (Norway), in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a), peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured as high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2-related shifts in nutrient flow into different phytoplankton groups (mainly dinoflagellates, prasinophytes and haptophytes) could have consequences for future organic matter flow to higher trophic levels and export production, with consequences for ecosystem productivity and atmospheric CO2.publishedVersio

Assessing Site Specificity of Osteoarthritic Gait Kinematics with Wearable Sensors and Their Association with Patient Reported Outcome Measures (PROMs): Knee versus Hip Osteoarthritis

There is a great need for quantitative outcomes reflecting the functional status in patients with knee or hip osteoarthritis (OA) to advance the development and investigation of interventions for OA. The purpose of this study was to determine if gait kinematics specific to the disease-i.e., knee versus hip OA-can be identified using wearable sensors and statistical parametric mapping (SPM) and whether disease-related gait deviations are associated with patient reported outcome measures. 113 participants (N = 29 unilateral knee OA; N = 30 unilateral hip OA; N = 54 age-matched asymptomatic persons) completed gait analysis with wearable sensors and the Knee/Hip Osteoarthritis Outcome Score (KOOS/HOOS). Data were analyzed using SPM. Knee and hip kinematics differed between patients with knee OA and patients with hip OA (up to 14°, p < 0.001 for knee and 8°, p = 0.003 for hip kinematics), and differences from controls were more pronounced in the affected than unaffected leg of patients. The observed deviations in ankle, knee and hip kinematic trajectories from controls were associated with KOOS/HOOS in both groups. Capturing gait kinematics using wearables has a large potential for application as outcome in clinical trials and for monitoring treatment success in patients with knee or hip OA and in large cohorts representing a major advancement in research on musculoskeletal diseases

Impact of total hip arthroplasty on pain, walking ability, and cardiovascular fitness

We tested the hypothesis that total hip arthroplasty (THA) patients have less pain and are able to walk longer post-operatively than pre-operatively, and that THA patients before and after have higher heart rates and compromised gas exchange determinants at rest and following exercise compared to healthy subjects with a post-operative improvement. Fifty-two patients completed questionnaires and an incremental walking stress test pre-operatively and 6-months after THA. Twenty-four age-matched control subjects completed the same stress test. Fifty-one patients had less pain 6-months after THA compared to pre-operative levels. Forty-three patients showed an improvement of at least one walking duration category. Patients had compromised cardiovascular fitness compared to the control group with a tendency to improve after THA. Hence, 6-months following THA, deficits exist other than reduced strength as reported in the literature. Prior to THA, the ability to walk longer is compromised by pain and not by poor cardiovascular fitness. Studies on specific rehabilitation programs of varying intensities may demonstrate opportunities to improve the cardiovascular fitness of this population

The role of muscle degeneration and spinal balance in the pathophysiology of lumbar spinal stenosis: Study protocol of a translational approach combining in vivo biomechanical experiments with clinical and radiological parameters.

ObjectiveTo describe a study protocol for investigating the functional association between posture, spinal balance, ambulatory biomechanics, paraspinal muscle fatigue, paraspinal muscle quality and symptoms in patients with symptomatic lumbar spinal stenosis (sLSS) before and 1-year after elective surgical intervention.DesignSingle-centre prospective, experimental, multimodal (clinical, biomechanical, radiological) study with three instances of data collection: baseline (study visit 1), 6-month follow-up (remote) and 1-year follow-up (study visit 2). Both study visits include an in vivo experiment aiming to elicit paraspinal muscle fatigue for postural assessment in a non-fatigued and fatigued state.Experimental protocolAt baseline and 1-year follow-up, 122 patients with sLSS will be assessed clinically, perform the back-performance scale assessment and complete several patient-reported outcome measure (PROMs) questionnaires regarding overall health, disease-related symptoms and kinesiophobia. Posture and biomechanical parameters (joint kinematics, kinetics, surface electromyography, back curvature) will be recorded using an optoelectronic system and retroreflective markers during different tasks including overground walking and movement assessments before and after a modified Biering-Sørensen test, used to elicit paraspinal muscle fatigue. Measurements of muscle size and quality and the severity of spinal stenosis will be obtained using magnetic resonance imaging (MRI) and sagittal postural alignment data from EOS radiographies. After each study visit, physical activity level will be assessed during 9 days using a wrist-worn activity monitor. In addition, physical activity level and PROMs will be assessed remotely at 6-month follow-up.ConclusionThe multimodal set of data obtained using the study protocol described in this paper will help to expand our current knowledge on the pathophysiology, biomechanics, and treatment outcome of degenerative sLSS. The results of this study may contribute to defining and/or altering patient treatment norms, surgery indication criteria and post-surgery rehabilitation schedules.Trial registrationThe protocol was approved by the regional ethics committee and has been registered at clinicaltrials.gov (NCT05523388)