Age related deviation of gait from normality in alkaptonuria.

Alkaptonuria is a rare metabolic disease leading to systemic changes including early and severe arthropathy which affects mobility. Due to unknown reasons, the onset of degenerative changes is delayed to around 30 years of age when both objective and subjective symptoms develop. In order to complement describing the structural changes in alkaptonuria with measures of movement function, clinical gait analysis was added to the list of assessments in 2013. The aim of this study was to describe the deviation of gait from normality as a function of age in patients with alkaptonuria. Three-dimensional movement of reflective markers attached to joints were captured during walking in 39 patients and 10 controls. Subsequent to processing the data to emphasise the shape of marker trajectories, the mean Movement Deviation Profile was generated for all participants. This single number measure gives the deviation of a patient’s gait from a distributed definition of gait normality. Results showed that gait deviation roughly follows a sigmoid profile with minimal increase of gait deviations in a younger patient group and an abrupt large increase around the second half of the 4th decade of life. Larger variations of gait deviations were found in the older group than in the younger group suggesting a complex interaction of multiple factors which determine gait function after symptoms manifest. Continued gait analysis of adults with AKU, extended to younger adults and children with AKU, is expected to complete understanding of both the natural history of alkaptonuria and how interventions can affect movement function

NLRP2 controls age-associated maternal fertility

Nucleotide-binding domain and leucine-rich repeat (NLR) proteins are well-known for their key roles in the immune system. Ectopically expressed NLRP2 in immortalized cell lines assembles an inflammasome and inhibits activation of the proinflammatory transcription factor NF-kappa B, but the physiological roles of NLRP2 are unknown. Here, we show that Nlrp2-deficient mice were born with expected Mendelian ratios and that Nlrp2 was dispensable for innate and adaptive immunity. The observation that Nlrp2 was exclusively expressed in oocytes led us to explore the role of Nlrp2 in parthenogenetic activation of oocytes. Remarkably, unlike oocytes of young adult Nlrp2-deficient mice, activated oocytes of mature adult mice developed slower and largely failed to reach the blastocyst stage. In agreement, we noted strikingly declining reproductive rates in vivo with progressing age of female Nlrp2-deficient mice. This work identifies Nlrp2 as a critical regulator of oocyte quality and suggests that NLRP2 variants with reduced activity may contribute to maternal age-associated fertility loss in humans

Primary and submovement control of aiming in C6 tetraplegics following posterior deltoid transfer

Background: Upper limb motor control in fast, goal-directed aiming is altered in tetraplegics following posterior-deltoid musculotendinous transfer. Specifically, movements have similar end-point accuracy but longer duration and lower peak velocity than those of age-matched, neurotypical controls. Here, we examine in detail the interplay between primary movement and submovement phases in five C6 tetraplegic and five control participants. Methods: Aiming movements were performed in two directions (20 cm away or toward), with or without vision. Trials that contained a submovement phase (i.e., discontinuity in velocity, acceleration or jerk) were identified. Discrete kinematic variables were then extracted on the primary and submovements phases. Results: The presence of submovements did not differ between the tetraplegic (68%) and control (57%) groups, and almost all submovements resulted from acceleration and jerk discontinuities. Tetraplegics tended to make a smaller amplitude primary movement, which had lower peak velocity and greater spatial variability at peak velocity. This was followed by a larger amplitude and longer duration secondary submovement. Peak velocity of primary movement was not related to submovement incidence. Together, the primary and submovement phases of both groups were equally effective in reducing end-point error. Conclusions: C6 tetraplegic participants exhibit some subtle differences in measures of motor behaviour compared to control participants, but importantly feedforward and feedback processes work effectively in combination to achieve accurate goal-directed aiming. Keywords: Tetraplegia, Aiming, Submovement, Upper-limb control, Muscle transfe

Manipulation of visual biofeedback during gait with a time delayed adaptive Virtual Mirror Box.

A mirror placed in the mid-sagittal plane of the body has been used to reduce phantom limb pain and improve movement function in medical conditions characterised by asymmetrical movement control. The mirrored illusion of unimpaired limb movement during gait might enhance the effect, but a physical mirror is only capable of showing parallel movement of limbs in real time typically while sitting. We aimed to overcome the limitations of physical mirrors by developing and evaluating a Virtual Mirror Box which delays the mirrored image of limbs during gait to ensure temporal congruency with the impaired physical limb

Interactive effects of elevated CO <inf>2</inf> and drought on nocturnal water fluxes in Eucalyptus saligna

Nocturnal water flux has been observed in trees under a variety of environmental conditions and can be a significant contributor to diel canopy water flux. Elevated atmospheric CO 2 (elevated [CO 2]) can have an important effect on day-time plant water fluxes, but it is not known whether it also affects nocturnal water fluxes. We examined the effects of elevated [CO 2] on nocturnal water flux of field-grown Eucalyptus saligna trees using sap flux through the tree stem expressed on a sapwood area (J s) and leaf area (E t) basis. After 19 months growth under well-watered conditions, drought was imposed by withholding water for 5 months in the summer, ending with a rain event that restored soil moisture. Reductions in J s and E t were observed during the severe drought period in the dry treatment under elevated [CO 2], but not during moderate- and post-drought periods. Elevated [CO 2] affected night-time sap flux density which included the stem recharge period, called 'total night flux' (19:00 to 05:00, J s,r), but not during the post-recharge period, which primarily consisted of canopy transpiration (23:00 to 05:00, J s,c). Elevated [CO 2] wet (EW) trees exhibited higher J s,r than ambient [CO 2] wet trees (AW) indicating greater water flux in elevated [CO 2] under well-watered conditions. However, under drought conditions, elevated [CO 2] dry (ED) trees exhibited significantly lower J s,r than ambient [CO 2] dry trees (AD), indicating less water flux during stem recharge under elevated [CO 2]. J s,c did not differ between ambient and elevated [CO 2]. Vapour pressure deficit (D) was clearly the major influence on night-time sap flux. D was positively correlated with J s,r and had its greatest impact on J s,r at high D in ambient [CO 2]. Our results suggest that elevated [CO 2] may reduce night-time water flux in E. saligna when soil water content is low and D is high. While elevated [CO 2] affected J s,r, it did not affect day-time water flux in wet soil, suggesting that the responses of J s,r to environmental factors cannot be directly inferred from day-time patterns. Changes in J s,r are likely to influence pre-dawn leaf water potential, and plant responses to water stress. Nocturnal fluxes are clearly important for predicting effects of climate change on forest physiology and hydrology. © 2011 The Author. Published by Oxford University Press. A ll rights reserved

An assessment of validity and responsiveness of generic measures of health-related quality of life in hearing impairment

This article is made available through the Brunel Open Access Publishing Fund. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Purpose: This review examines psychometric performance of three widely used generic preference-based measures, that is, EuroQol 5 dimensions (EQ-5D), Health Utility Index 3 (HUI3) and Short-form 6 dimensions (SF-6D) in patients with hearing impairments. Methods: A systematic search was undertaken to identify studies of patients with hearing impairments where health state utility values were measured and reported. Data were extracted and analysed to assess the reliability, validity (known group differences and convergent validity) and responsiveness of the measures across hearing impairments. Results: Fourteen studies (18 papers) were included in the review. HUI3 was the most commonly used utility measures in hearing impairment. In all six studies, the HUI3 detected difference between groups defined by the severity of impairment, and four out of five studies detected statistically significant changes as a result of intervention. The only study available suggested that EQ-5D only had weak ability to discriminate difference between severity groups, and in four out of five studies, EQ-5D failed to detected changes. Only one study involved the SF-6D; thus, the information is too limited to conclude on its performance. Also evidence for the reliability of these measures was not found. Conclusion: Overall, the validity and responsiveness of the HUI3 in hearing impairment was good. The responsiveness of EQ-5D was relatively poor and weak validity was suggested by limited evidence. The evidence on SF-6D was too limited to make any judgment. More head-to-head comparisons of these and other preference measures of health are required.Medical Research Counci

Rooting depth explains [CO <inf>2</inf>]× drought interaction in Eucalyptus saligna

Elevated atmospheric [CO 2] (eCa) often decreases stomatal conductance, which may delay the start of drought, as well as alleviate the effect of dry soil on plant water use and carbon uptake. We studied the interaction between drought and eCa in a whole-tree chamber experiment with Eucalyptus saligna. Trees were grown for 18 months in their Ca treatments before a 4-month dry-down. Trees grown in eCa were smaller than those grown in ambient Ca (aCa) due to an early growth setback that was maintained throughout the duration of the experiment. Pre-dawn leaf water potentials were not different between Ca treatments, but were lower in the drought treatment than the irrigated control. Counter to expectations, the drought treatment caused a larger reduction in canopy-average transpiration rates for trees in the eCa treatment compared with aCa. Total tree transpiration over the dry-down was positively correlated with the decrease in soil water storage, measured in the top 1.5 m, over the drying cycle; however, we could not close the water budget especially for the larger trees, suggesting soil water uptake below 1.5 m depth. Using neutron probe soil water measurements, we estimated fractional water uptake to a depth of 4.5 m and found that larger trees were able to extract more water from deep soil layers. These results highlight the interaction between rooting depth and response of tree water use to drought. The responses of tree water use to eCa involve interactions between tree size, root distribution and soil moisture availability that may override the expected direct effects of eCa. It is essential that these interactions be considered when interpreting experimental results. © 2011 The Author. Published by Oxford University Press. A ll rights reserved

Whole-tree chambers for elevated atmospheric CO<inf>2</inf> experimentation and tree scale flux measurements in south-eastern Australia: The Hawkesbury Forest Experiment

Resolving ecophysiological processes in elevated atmospheric CO2 (Ca) at scales larger than single leaves poses significant challenges. Here, we describe a field-based experimental system designed to grow trees up to 9m tall in elevated Ca with the capacity to control air temperature and simultaneously measure whole-tree gas exchange. In western Sydney, Australia, we established the Hawkesbury Forest Experiment (HFE) where we built whole-tree chambers (WTC) to measure whole-tree CO2 and water fluxes of an evergreen broadleaf tree, Eucalyptus saligna. A single E. saligna tree was grown from seedling to small tree within each of 12 WTCs; six WTCs were maintained at ambient Ca and six WTCs were maintained at elevated Ca, targeted at ambient Ca +240μmolmol-1. All 12 WTCs were controlled to track ambient outside air temperature (Tair) and air water vapour deficit (Dair). During the experimental period, Tair, Dair and Ca in the WTCs were within 0.5°C, 0.3kPa, and 15μmolmol-1 of the set-points for 90% of the time, respectively. Diurnal responses of whole-tree CO2 and water vapour fluxes are analysed, demonstrating the ability of the tree chamber system to measure rapid environmental responses of these fluxes of entire trees. The light response of CO2 uptake for entire trees showed a clear diurnal hysteresis, attributed to stomatal closure at high Dair. Tree scale CO2 fluxes confirm the hypothesised deleterious effect of chilling night-time temperatures on whole-tree carbon gain in this subtropical Eucalyptus. The whole-tree chamber flux data add an invaluable scale to measurements in both ambient and elevated Ca and allow us to elucidate the mechanisms driving tree productivity responses to elevated Ca in interaction with water availability and temperature. © 2010 Elsevier B.V