Research in stability of periodic motions Quarterly progress report, 5 May - 4 Aug. 1966

Instability of periodic orbits in restricted and reduced three-body problems using mapping by fixed point metho

Das Heiligtum von Olympia im 2. Jahrhundert n. Chr.: alte und neue Impressionen

The Altis of Olympia in the time of Herodes Atticus

Das Heiligtum von Olympia im 2. Jahrhundert n. Chr.: alte und neue Impressionen

The Altis of Olympia in the time of Herodes Atticus

Cognitive function in soccer athletes determined by sleep disruption and self-reported health, yet not by decision-reinvestment

BackgroundSleep disruption (SD) increases sympathetic activity and cortisol secretion, and delays cognitive functions such as reaction-time (RT). Sympathetic activity of disturbed sleepers, is similar to those of so-called decision-reinvesters. Decision-reinvestment refers to traits in individuals with greater tendency to ruminate and reinvest in their decisions, with significant decrease in both motor-control and cognitive performance. Decision-making quality is a crucial attribute to athletic performance which relies on RT. Consequently, SD affects pitch-performance negatively, particularly in decision-reinvesters. This observational pilot-study examined the relationship between SD and cognitive function, perceived health, as well as reinvestment strategies. The hypothesis was that athletes with lower SD perceive their health better, report lower stress levels, perform better in cognitive tasks, and show lower tendency for decision-reinvestment.MethodsTwenty-one football player recorded their sleep with fit-trackers for 7 nights. Participants self-reported their mental and physical health, decision-reinvestment strategy, sleep behaviour, and perceived stress levels. Athletes then performed a set of cognitive tests to examine memory function (Backwards Corsi), selective attention (STROOP), and cognitive flexibility (Wisconsin Card Sorting Test, WCST). Normality was tested with a Shapiro-Wilk test, and analysed with a Pearson's or Spearman's correlation test.ResultsSignificant correlation appeared between extended sleep-interruptions and Backwards Corsi RT, r = 0.66, p = 0.010, as further in total sleep time and wellbeing r = 0.50, p = 0.029. A negative correlation exist in regard of pain scores and Backwards Corsi scores r = −0.57, p = 0.110. Physical health correlated with error-rates in the WCST, r = 0.69, p ≤ 0.001. Also, reinvestment negatively correlated with physical health, r = −0.80, p ≤ 0.001.ConclusionWellbeing relies on total sleep-time. Athletes with extended sleep-interruptions are slower in recalling memory, and those with greater reported pain have lower memory scores. Participants who rate physical health greater, have more error-rates in the WCST; indicating that cognitive flexibility is enhanced in individuals with inferior perceived health. However, individuals with lower physical health scores also have greater tendency to ruminate and reinvest in decisions, suggesting interrelation between reinvestment and physical health

Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste

[EN] The organic fraction of municipal solid waste was identified as an alternative phosphorus resource: hydrothermal carbonization provided phosphorus-rich hydrochar. Two alternative valorization pathways can be considered for the latter: the use as a fertilizer or as solid fuel after phosphorus extraction. By means of life cycle assessment (LCA) the environmental impact of extracting phosphorus and using the hydrochar as solid fuel was evaluated. Therefore, in a first step, phosphorus extraction with nitric acid, hydrochloric acid and sulfuric acid was experimentally investigated on laboratory scale. Nitric acid proved to be the most suitable because it offered high extraction efficiency and improved solid fuel properties such as lower ash content and lower levels of chlorine and sulfur. In contrast, hydrochloric acid increased the chlorine content and sulfuric acid only replaced phosphate by sulfate, but did not reduce the ash content of hydrochar. Then phosphorus can be precipitated and used as fertilizer. Although technically feasible, LCA points out that the separate use of hydrochar and phosphorus represents an overall environmental burden for wide range of impact categories, including climate change and resource depletion. Therefore, other applications for phosphorus-rich hydrochars, like agriculture and horticulture, should be considered.The authors are grateful for the financial support received from the Spanish Ministry of Economy and Competiveness under the RTC-2015-4017-3 of the state programme "Research, Development and Innovation Oriented to the Challenges of Society"Oliver-Tomás, B.; Hitzl, M.; Owsianiak, M.; Renz, M. (2019). Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste. Resources Conservation and Recycling. 147:111-118. https://doi.org/10.1016/j.resconrec.2019.04.023S11111814

Is loss in femorotibial cartilage thickness related to severity of contra-lateral radiographic knee osteoarthritis? – Longitudinal data from the Osteoarthritis Initiative

SummaryObjectiveAnti-catabolic disease modifying drugs (DMOADs) aim to reduce cartilage loss in knee osteoarthritis (KOA). Testing such drugs in clinical trials requires sufficient rates of loss in the study participants to occur, preferably at a mild disease stage where cartilage can be preserved. Here we analyze a “progression” model in mild radiographic KOA (RKOA), based on contra-lateral radiographic status.MethodsWe studied 837 participants (62.4 ± 9 yrs; 30 ± 4.9 kg/m²; 61.8% women) from the Osteoarthritis Initiative (OAI) with mild to moderate RKOA (Kellgren Lawrence grade [KLG] 2–3) and with/without Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing (JSN). These had quantitative measurements of subregional femorotibial cartilage thickness from magnetic resonance imaging (MRI) at baseline and 1-year follow-up. They were stratified by contra-lateral knee status: no (KLG 0/1), definite (KLG2) and moderate RKOA (KLG 3/4).ResultsKLG2 knees with JSN and moderate contra-lateral RKOA had (P = 0.008) greater maximum subregional cartilage loss −220 μm [95% confidence interval (CI) −255, −184 μm] than those without contra-lateral RKOA −164 μm [−187, −140 μm]. Their rate of subregional cartilage loss was similar and not significantly different (P = 0.61) to that in KLG 3 knees without contra-lateral RKOA (−232 μm; [−266; −198 μm]). The effect of contra-lateral RKOA status was less in KLG2 knees without JSN, and in KLG3 knees.ConclusionKLG2 knees with JSN and moderate contra-lateral RKOA, display relatively high rates of subregional femorotibial cartilage loss, despite being at a relatively mild stage of RKOA. They may therefore provide a unique opportunity for recruitment in clinical trials that explore the efficacy of anti-catabolic DMOADs on structural progression

Environmental Performance of Hydrothermal Carbonization of Four Wet Biomass Waste Streams at Industry-Relevant Scales

[EN] Hydrothermal carbonization (HTC) of green waste, food waste, organic fraction of municipal solid waste (MSW), and digestate is assessed using life cycle assessment as a potential technology to treat biowaste. Water content of the biowaste and composition of the resulting hydrochar are important parameters influencing environmental performance. Hydrochar produced from green waste performs best and second best in respectively 2 and 10 out of 15 impact categories, including climate change, mainly due to low transportation needs of the biowaste and optimized pumping efficiency for the feedstock. By contrast, hydrochar produced from the organic fraction of MSW performs best in 6 impact categories, but has high potential impacts on human health and ecosystems caused by emissions of toxic elements through ash disposal. The greatest potential for environmental optimization for the HTC technology is in the use of heat and electricity with increasing plant size, but its overall environmental performance is largely influenced in a given geographic location by the incumbent waste management system that it replaces. Impact scores are within the range of existing alternative treatment options, suggesting that despite being relatively immature technology, and depending on the geographic location of the plant, HTC may be an attractive treatment option for biowaste.This research was funded by the European Commission under the seventh framework program; SME-2013-2: NEWAPP, grant agreement 605178.Owsianiak, M.; Ryberg, MW.; Renz, M.; Hitzl, M.; Hauschildt, MZ. (2016). Environmental Performance of Hydrothermal Carbonization of Four Wet Biomass Waste Streams at Industry-Relevant Scales. ACS Sustainable Chemistry and Engineering. 4(12):6783-6791. https://doi.org/10.1021/acssuschemeng.6b01732S6783679141

Fuel and chemicals from wet lignocellulosic biomass waste streams by hydrothermal carbonization

[EN] Most valorization processes for biomass waste require dry raw material or at least a relatively low amount of residual humidity. In contrast, hydrothermal carbonization (HTC) is a valorization process for lignocellulosic biomass which uses water as a reaction medium. The product, hydrochar, can be used as dry solid fuel making the post-process drying procedure much more energy-efficient. Herein, three lignocellulosic biomass waste feedstocks, i.e. the organic fraction of municipal solid waste (OFMSW), orange peel waste (OPW) and the residues of a pepper plantation, were processed by HTC on a ton scale and the product evaluated as solid fuel in form of pellets for domestic use (EN ISO 17225). A critical property of the product is the ash content which has to be adjusted by post-treatment. Ash content below the established limit was achieved by acid treatment with sulfuric acid. An implementation of the treatment into the pilot plant is straightforward. An organic liquid fraction was obtained as an additional effluent in the pilot plant depending on the biomass feedstock. For instance, limonene in a mixture with other monoterpenes was separated when orange peel waste was processed, constituting approximately 3 wt% of the dry matter. It is further shown at laboratory scale that the monoterpene mixture can be directly used or can easily be transformed into para-cymene, a fragrance compound, by catalytic dehydrogenation. Therefore, the HTC process can be considered as a source for valuable apolar platform molecules derived from lignocellulosic biomass waste in addition to the production of hydrochar.Authors are grateful for financial support from the EU (FP7-SME-2013-605178-NEWAPP) and from the Spanish Ministry of Economy and Competitiveness (Innpacto Programme, IPT-2012-0023-120000). We thank our NEWAPP partners (http://newapp-project.eu/en/partners.html), especially M. Ryberg and M. Owsianiak from the Technical University of Denmark (DTU) and L. Doyle from TTZ Bremerhaven, for fruitful discussions and valuable suggestions.Burguete Llorens, PL.; Corma Canós, A.; Hitzl, M.; Modrego Latorre, R.; Ponce Ballester, E.; Renz, M. (2016). Fuel and chemicals from wet lignocellulosic biomass waste streams by hydrothermal carbonization. Green Chemistry. 18(4):1051-1060. https://doi.org/10.1039/C5GC02296GS1051106018