Low Frequency Fatigue in Human Quadriceps is Fatigue Dependent and Not Task Dependent

It is well accepted that a low intensity/long duration isometric contraction induces more low frequency fatigue (LFF) compared to a high-intensity/short-duration contraction. However, previous reports examined the intensity/duration of the contraction but did not control the level of fatigue when concluding fatigue is task dependent. The purpose of this study was to determine whether a long duration/low intensity fatiguing contraction would induce greater LFF than a short duration/high-intensity contraction when the quadriceps muscle was fatigued to similar levels. Eighteen healthy male subjects performed quadriceps contractions sustained at 35% and 65% of maximal voluntary contraction (MVC) on separate days, until the tasks induced a similar amount of fatigue (force generating capacity = 45% MVC). Double pulse torque to single pulse torque ratio (D/S ratio) was obtained before, immediately and 5 min after fatigue along with the electromyographic (EMG) signal from vastus medialis (VM) and rectus femoris (RF). The D/S ratio significantly (p \u3c 0.05) increased by 8.7 ± 8.5% (mean ± SD) and 10.2 ± 9.2% after 35% and 65% tasks, respectively, and remained elevated 5 min into recovery; however, there was no significant difference in ratio between the two sessions immediately or 5 min post-fatigue (p \u3e 0.05) even though the endurance time for the 35% fatigue task (124 ± 39.68 s) was significantly longer (p = 0.05) than that of the 65% task (63 ± 17.73 s). EMG amplitude and median power frequency (MPF) analysis also did not reveal any significant differences between these two sessions after fatigue. These findings indicate that LFF fatigue is fatigue dependent as well as task intensity/duration dependent. These findings assist us in understanding task dependency and muscle fatigue

A nucleosomal function for IκB kinase-α in NF-κB-dependent gene expression

NF-κB is a principal transcriptional regulator of diverse cytokine-mediated processes and is tightly controlled by the IκB kinase complex (IKK-α/β/γ). IKK-β and IKK-γ are critical for cytokine-induced NF-κB function, whereas IKK-α is thought to be involved in other regulatory pathways. However, recent data suggest a role for IKK-α in NF-κB-dependent gene expression in response to cytokine treatment. Here we demonstrate nuclear accumulation of IKK-α after cytokine exposure, suggesting a nuclear function for this protein. Consistent with this, chromatin immunoprecipitation (ChIP) assays reveal that IKK-α was recruited to the promoter regions of NF-κB-regulated genes on stimulation with tumour-necrosis factor-α. Notably, NF-κB-regulated gene expression is suppressed by the loss of IKK-α and this correlates with a complete loss of gene-specific phosphorylation of histone H3 on serine 10, a modification previously associated with positive gene expression. Furthermore, we show that IKK-α can directly phosphorylate histone H3 in vitro, suggesting a new substrate for this kinase. We propose that IKK-α is an essential regulator of NF-κB-dependent gene expression through control of promoter-associated histone phosphorylation after cytokine exposure. These findings provide additional insight into the role of the IKK complex in NF-κB-regulated gene expression

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Information, Advocacy and Signposting as a Low-Level Support for Adults with High-Functioning Autism Spectrum Disorder: An Example from the UK

‘Low-level’ support is championed to support adults with high functioning autism spectrum disorder (HFASD) to achieve good quality health and social care, yet research in the area is sparse. Drawing on semi-structured interview data, this paper considers the efficacy of an intervention to provide low-level support to adults with HFASD with little or no funded support. The intervention led to a number of perceived positive outcomes for adults with HFASD, their families, and service providers in the city, including increased access to education, volunteering, support and information, socialising, improved health and wellbeing, and managing day-to-day. Although many of life’s difficulties still persisted, the intervention helped service users overcome barriers to availing further support, possibly leading to beneficial outcomes down the line

Shaping 3D root system architecture

Plants are sessile organisms rooted in one place. The soil resources that plants require are often distributed in a highly heterogeneous pattern. To aid foraging, plants have evolved roots whose growth and development are highly responsive to soil signals. As a result, 3D root architecture is shaped by myriad environmental signals to ensure resource capture is optimised and unfavourable environments are avoided. The first signals sensed by newly germinating seeds — gravity and light — direct root growth into the soil to aid seedling establishment. Heterogeneous soil resources, such as water, nitrogen and phosphate, also act as signals that shape 3D root growth to optimise uptake. Root architecture is also modified through biotic interactions that include soil fungi and neighbouring plants. This developmental plasticity results in a ‘custom-made’ 3D root system that is best adapted to forage for resources in each soil environment that a plant colonises