Portable tensiomyography and myotonometry devices have been developed to measure mechanical and contractile properties of skeletal muscle.The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris muscle (BF) as a result of change in knee joint angle (i.e. muscle length).BF responses were assessed in sixteen young participants (23.4±4.9 years), at three knee joint angles (0, 45, and 90 degrees), for maximal isometric torque (MIT) along with myoelectrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the tensiomyography and myotonometry was also assessed.MIT changed significantly (p<0.01) across the three angles, so did stiffness and other parameters measured with myotonometry (p<0.01). Conversely, tensiomyography could detect changes only at two knee angles (0 and 45 deg, p<0.01), when there is enough tension in the muscle. Reliability was overall insufficient for tensiomyography whilst absolute reliability was excellent (CV < 5%) for myotonometry.The ability of myotonometry more than tensiomyography to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

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The biological health of soil is an important aspect of soil quality because of the many critical functions performed by organisms in soil. Various indicators of soil quality have been proposed, but measurements of microbial biomass are most commonly used. During decomposition of plant residues in soil the relative intensities of the O-alkyl-C signal decreases and the alkyl-C signal increases in nuclear magnetic resonance (NMR) spectra. This leads to the suggestion that the alkyl-C to O-alkyl-C ratio of a soil may indicate the degree of decomposition. Consequently, the overall resource quality of soil C as a substrate for heterotrophic microorganisms may be inversely related to the alkyl-C to O-alkyl-C ratio. Our hypothesis is that a relationship exists between the size of the soil microbial community (microbial biomass) and the quality of soil carbon as a resource for microorganisms. New data have been combined with previously published data to show that there was a significant, negative correlation between the biomass C to total C (Cmic, to Corg) ratio and the alkyl-C to O-alkyl-C ratio (p < 0.01), which supports our hypothesis.

Severe fires in 1957 and 1976 removed the vegetation and soil organic matter from the litter layers and organic horizons of soils at two adjacent moorland sites leaving exposed the uppermost mineral horizon of the soil. In the period since, plant recolonization and soil organic matter reaccumulation have occurred to give a chronosequence. Assuming no major changes in the carbon and nitrogen content of the unburned soil since 1957, the rates of accumulation of soil C and N were estimated to be 0.035 kg C m–2 y–1 and 0.001 kg N m–2 y–1 over the first 19 years, and 0.50 kg C m–2 y–1 and 0.023 kg N m–2 y–1 over the period from 19 to 38 years after burning. Solid‐state 13C NMR (cross‐polarization, magic angle spinning 13C nuclear magnetic resonance spectroscopy) showed that the ratio of alkyl‐ and methyl‐C‐to‐O‐alkyl‐C increased with stage of decomposition and in the unburned soil with decreasing particle‐size. For the organic matter that had reaccumulated in the 1957‐burned soil, the alkyl‐C‐to‐O‐alkyl‐C ratio of the > 2000 μm and 2000–250 μm particle‐size fractions were greater than those of the corresponding size fractions from the unburned soil, indicating that the reaccumulated soil organic matter was subject to decomposition but limited fragmentation or comminution.