1,162 research outputs found

    Reworked Middle Pleistocene deposits preserved in the core region of the Fennoscandian Ice Sheet

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    Publisher Copyright: © 2020 The AuthorsDuring successive Pleistocene ice ages, Finnish Lapland lay under the cold-based centre of the Fennoscandian Ice Sheet (FIS). This area largely escaped deep glacial erosion by the fast-flowing wet-based ice streams that developed toward the periphery of successive ice sheets. Low erosion is evident from the preservation of Neogene weathered bedrock and a significant record of tills of the pre-Weichselian sediments. To date, some 250 locations are known where sediments occur beneath and within last glaciation deposits (Weichselian). An ongoing challenge is to determine absolute ages for old sediments and to establish regional stratigraphic correlations from one site to another. At Äältövittikot, lacustrine silts and rippled sands are found as rafts and inter-till layers within the Weichelian tills. The results indicate an age range of 190–235 ka identifying a likely MIS 7 age i.e., an early or mid Saalian Stage for the older sediments and a couple of younger OSL ages representing Weichselian interstadials as an indication for the multiphase deposition of the Äältövittikot sediment complex. Overlying Weichselian tills contain large amounts of glaciotectonically-deformed and reworked Saalian material. The reworking of Saalian sediment in an up-ice position from the headward erosion zone of the Salla ice stream is important for understanding the polycyclic origins of tills found in similar locations and for interpretation of tracer minerals found in mineral exploration surveys in similar glaciated terrains.Peer reviewe

    Physioacoustic Therapy: Placebo Effect on Recovery From Exercise-Induced Muscle Damage

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    We evaluated claims that physioacoustic therapy can enhance muscle healing following damaging exercise. Untrained subjects were randomly assigned to control (C), placebo (P) or treatment (T) groups. All groups performed 70 eccentric triceps contractions followed by; no treatment (C), sham physioacoustic treatment (P), or actual physioacoustic therapy (T) on days 1–4 post-exercise. Muscle soreness and isometric and concentric triceps peak torque were determined preexercise and on days 1–4 and 7 post-exercise. The T group received physioacoustic therapy for 30 min/day on the treatment days. The P group believed they received physioacoustic therapy, although the chairs were turned off. Peak torques were depressed (P \u3c 0.05) on days 1–3 in all groups and returned to pre-exercise values by days 4–7 in both P and T groups. C group peak torques remained depressed (P \u3c 0.05) through day 7. Soreness was elevated (P \u3c 0.05) in all groups on days 1–2 post-exercise. P and T groups reported no soreness by day 3 while the C group remained sore (P \u3c 0.05) through days 3–4. The T group recovered soreness and force faster than C but at a similar rate to the P group. The effectiveness of physioacoustic therapy in enhancing post-exercise muscle healing may be attributable to a placebo effect

    Physioacoustic Therapy: Placebo Effect on Recovery From Exercise-Induced Muscle Damage

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    We evaluated claims that physioacoustic therapy can enhance muscle healing following damaging exercise. Untrained subjects were randomly assigned to control (C), placebo (P) or treatment (T) groups. All groups performed 70 eccentric triceps contractions followed by; no treatment (C), sham physioacoustic treatment (P), or actual physioacoustic therapy (T) on days 1–4 post-exercise. Muscle soreness and isometric and concentric triceps peak torque were determined preexercise and on days 1–4 and 7 post-exercise. The T group received physioacoustic therapy for 30 min/day on the treatment days. The P group believed they received physioacoustic therapy, although the chairs were turned off. Peak torques were depressed (P \u3c 0.05) on days 1–3 in all groups and returned to pre-exercise values by days 4–7 in both P and T groups. C group peak torques remained depressed (P \u3c 0.05) through day 7. Soreness was elevated (P \u3c 0.05) in all groups on days 1–2 post-exercise. P and T groups reported no soreness by day 3 while the C group remained sore (P \u3c 0.05) through days 3–4. The T group recovered soreness and force faster than C but at a similar rate to the P group. The effectiveness of physioacoustic therapy in enhancing post-exercise muscle healing may be attributable to a placebo effect

    External training loads and smartphone-derived heart rate variability indicate readiness to train in elite soccer

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    Player readiness can affect the ability to perform and tolerate prescribed training load (TL); therefore, in a time-efficient and practice compatible manner, practitioners need objective evidence to inform readiness to train. Six male professional footballers (mean ± standard deviation [SD]; 26 ± 2 years, 79.0 ± 4.9 kg, 1.82 ± 0.05 m) participated. Heart rate variability (HRV) was recorded using a smartphone application prior to the daily training sessions (247 training sessions [41.17 ± 7.41 per player]). External TL was monitored during training using global positioning system devices. Linear mixed models were used to examine variations in HRV and TL across the study period and to determine relationships between HRV and TL. Differences in TL and HRV were expressed as standardised effect sizes (ES) ± 90% confidence limits. Changes in HRV (outcome) were expressed as the expected change for a 2-SD change in TL (predictor). Across the study period, all external TL measures varied substantially, demonstrating weekly fluctuations in load (ES range = 0.00–7.40). The relationship between morning HRV and external TL ranged from −0.10 for distance and 1.89 for equivalent distance index (EDI). Overall, EDI demonstrated the strongest relationship with morning HRV; therefore, EDI and smartphone-derived HRV may provide an indicator of readiness to train within elite soccer

    Assessing Peracetic Acid Application Methodology and Impacts on Fluidized Sand Biofilter Performance

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    Nitrifying biofilters oxidize harmful ammonia excreted by fish into less toxic nitrate within recirculating aquaculture systems (RAS). Biofilter performance and resulting RAS water quality largely depend on a robust microbiome that effectively converts nitrogenous wastes; however, occasional use of water disinfectants may also be necessary to reduce or eliminate specific fish pathogens. Disinfectants and sanitizers such as peracetic acid (PAA) work by disrupting microbial activity and could unintentionally alter the microbially-driven nitrification biofiltration process if allowed to circulate within an RAS. Furthermore, the target concentration and application method of PAA may influence the level of biofilter disruption. For this study, 12 replicated experimental-scale fluidized sand biofilters were dosed with PAA to achieve target concentrations ranging from 1.0-–2.5 mg/L, a typical low-dose treatment range to reduce or eliminate opportunistic pathogens. Two application methods were compared, including (i) a single pulse of PAA added every other day for five days, and (ii) smaller doses of PAA added every five minutes over four hours. The PAA decay was monitored and predosing and postdosing water quality parameters were assessed. Regardless of the target concentration or application method, PAA addition within the tested range did not cause significant disruption to the biofilters’ nitrification processes. This research demonstrates that PAA may be a viable water sanitizer for the RAS industry, although further research to refine safe application protocols is necessary.Assessing Peracetic Acid Application Methodology and Impacts on Fluidized Sand Biofilter PerformancepublishedVersio

    Providing security for wireless community networks

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    This paper describes a new Internet access paradigm based on Lowest Cost Denominator Networking - the Public Access WiFi Service (PAWS) - that utilises the unused capacity of home broadband connections and provides users who are unable to afford paying for the service with Less-than-Best-Effort access to these resources. We identify the security and architectural challenges faced by the project and propose our solution that enables free internet connectivity to public services for the local community, in a secure and scalable manner
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