1,137 research outputs found

    Depopulation of dense α-synuclein aggregates is associated with rescue of dopamine neuron dysfunction and death in a new Parkinson's disease model.

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    Parkinson's disease (PD) is characterized by the presence of α-synuclein aggregates known as Lewy bodies and Lewy neurites, whose formation is linked to disease development. The causal relation between α-synuclein aggregates and PD is not well understood. We generated a new transgenic mouse line (MI2) expressing human, aggregation-prone truncated 1-120 α-synuclein under the control of the tyrosine hydroxylase promoter. MI2 mice exhibit progressive aggregation of α-synuclein in dopaminergic neurons of the substantia nigra pars compacta and their striatal terminals. This is associated with a progressive reduction of striatal dopamine release, reduced striatal innervation and significant nigral dopaminergic nerve cell death starting from 6 and 12 months of age, respectively. In the MI2 mice, alterations in gait impairment can be detected by the DigiGait test from 9 months of age, while gross motor deficit was detected by rotarod test at 20 months of age when 50% of dopaminergic neurons in the substantia nigra pars compacta are lost. These changes were associated with an increase in the number and density of 20-500 nm α-synuclein species as shown by dSTORM. Treatment with the oligomer modulator anle138b, from 9 to 12 months of age, restored striatal dopamine release, prevented dopaminergic cell death and gait impairment. These effects were associated with a reduction of the inner density of large α-synuclein aggregates and an increase in dispersed small α-synuclein species as revealed by dSTORM. The MI2 mouse model recapitulates the progressive dopaminergic deficit observed in PD, showing that early synaptic dysfunction is associated to fine behavioral motor alterations, precedes dopaminergic axonal loss and neuronal death that become associated with a more consistent motor deficit upon reaching a certain threshold. Our data also provide new mechanistic insight for the effect of anle138b's function in vivo supporting that targeting α-synuclein aggregation is a promising therapeutic approach for PD

    Achilles tendon moment arm length is smaller in children with cerebral palsy than in typically developing children

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    When studying muscle and whole-body function in children with cerebral palsy (CP), knowledge about both internal and external moment arms is essential since they determine the mechanical advantage of a muscle over an external force. Here we asked if Achilles tendon moment arm (MAAT) length is different in children with CP and age-matched typically developing (TD) children, and if MAAT can be predicted from anthropometric measurements. Sixteen children with CP (age: 10y 7 m ± 3y, 7 hemiplegia, 12 diplegia, GMFCS level: I (11) and II (8)) and twenty TD children (age: 10y 6 m ± 3y) participated in this case-control study. MAAT was calculated at 20° plantarflexion by differentiating calcaneus displacement with respect to ankle angle. Seven anthropometric variables were measured and related to MAAT. We found normalized MAAT to be 15% (∼7 mm) smaller in children with CP compared to TD children (p = 0.003). MAAT could be predicted by all anthropometric measurements with tibia length explaining 79% and 72% of variance in children with CP and TD children, respectively. Our findings have important implications for clinical decision making since MAAT influences the mechanical advantage about the ankle, which contributes to movement function and is manipulated surgically

    Learning To Be Affected: Social suffering and total pain at life’s borders.

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    The practice of Live Sociology in situations of pain and suffering is the author’s focus. An outline of the challenges of understanding pain is followed by a discussion of Bourdieu’s ‘social suffering’ (1999) and the palliative care philosophy of ‘total pain’. Using examples from qualitative research on disadvantaged dying migrants in the UK, attention is given to the methods that are improvised by dying people and care practitioners in attempts to bridge intersubjective divides, where the causes and routes of pain can be ontologically and temporally indeterminate and/or withdrawn. The paper contends that these latter phenomena are the incitement for the inventive bridging and performative work of care and Live Sociological methods, both of which are concerned with opposing suffering. Drawing from the ontology of total pain, I highlight the importance of (i) an engagement with a range of materials out of which attempts at intersubjective bridging can be produced, and which exceed the social, the material, and the temporally linear; and (ii) an empirical sensibility that is hospitable to the inaccessible and non-relational

    Sociological stalking? Methods, ethics and power in longitudinal criminological research

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    Scholarship on criminal careers and desistance from crime employing longitudinal methodologies has paid scant attention to sociological and anthropological debates regarding epistemology, reflexivity and researcher positionality. This is surprising in light of a recent phenomenological turn in desistance research wherein (former) lawbreakers’ identity, reflexivity, and self-understanding have become central preoccupations. In this article I interrogate aspects of the methodological ‘underside’ (Gelsthorpe, 2007) of qualitative longitudinal research with criminalised women through an examination of the surveillant position of the researcher. Focusing on methods, ethics and power, I examine some contradictions of feminist concerns to ‘give women voice’ in research involving re-tracing an over-surveilled and highly stigmatised population. I reflect on the effects of researcher positionality through a conceptualisation of re-tracing methods as, at worst, a form of sociological stalking

    Feminist phenomenology and the woman in the running body

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    Modern phenomenology, with its roots in Husserlian philosophy, has been taken up and utilised in a myriad of ways within different disciplines, but until recently has remained relatively under-used within sports studies. A corpus of sociological-phenomenological work is now beginning to develop in this domain, alongside a longer standing literature in feminist phenomenology. These specific social-phenomenological forms explore the situatedness of lived-body experience within a particular social structure. After providing a brief overview of key strands of phenomenology, this article considers some of the ways in which sociological, and particularly feminist phenomenology, might be used to analyse female sporting embodiment. For illustrative purposes, data from an autophenomenographic project on female distance running are also included, in order briefly to demonstrate the application of phenomenology within sociology, as both theoretical framework and methodological approach

    In-vivo monitoring for electrical expression of plant living parameters by an impedance lab system

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    We present a complete in-lab system to monitor the plant and its surrounding environment. The plant impedance is directly measured in a continuous manner, while, simultaneously surrounding environment parameters known to affect plant status, are monitored. This is done combining a new in-vivo direct measurement of the plant together with an embedded system using available sensor technology and a designated interface for continuous data acquisition. Furthermore, the next versions this system can be deployed as a field monitoring device, with simple adaptations

    Applying Stretch to Evoke Hyperreflexia in Spasticity Testing: Velocity vs. Acceleration

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    \ua9 Copyright \ua9 2021 Sloot, Weide, van der Krogt, Desloovere, Harlaar, Buizer and Bar-On. In neurological diseases, muscles often become hyper-resistant to stretch due to hyperreflexia, an exaggerated stretch reflex response that is considered to primarily depend on the muscle\u27s stretch velocity. However, there is still limited understanding of how different biomechanical triggers applied during clinical tests evoke these reflex responses. We examined the effect of imposing a rotation with increasing velocity vs. increasing acceleration on triceps surae muscle repsonse in children with spastic paresis (SP) and compared the responses to those measured in typically developing (TD) children. A motor-operated ankle manipulator was used to apply different bell-shaped movement profiles, with three levels of maximum velocity (70, 110, and 150\ub0/s) and three levels of maximum acceleration (500, 750, and 1,000\ub0/s2). For each profile and both groups, we evaluated the amount of evoked triceps surae muscle activation. In SP, we evaluated two additional characteristics: the intensity of the response (peak EMG burst) and the time from movement initiation to onset of the EMG burst. As expected, the amount of evoked muscle activation was larger in SP compared to TD (all muscles: p < 0.001) and only sensitive to biomechanical triggers in SP. Further investigation of the responses in SP showed that peak EMG bursts increased in profiles with higher peak velocity (lateral gastrocnemius: p = 0.04), which was emphasized by fair correlations with increased velocity at EMG burst onset (all muscles: r > 0.33–0.36, p ≤ 0.008), but showed no significant effect for acceleration. However, the EMG burst was evoked faster with higher peak acceleration (all muscles p < 0.001) whereas it was delayed in profiles with higher peak velocity (medial gastrocnemius and soleus: p < 0.006). We conclude that while exaggerated response intensity (peak EMG burst) seems linked to stretch velocity, higher accelerations seem to evoke faster responses (time to EMG burst onset) in triceps surae muscles in SP. Understanding and controlling for the distinct effects of different biological triggers, including velocity, acceleration but also length and force of the applied movement, will contribute to the development of more precise clinical measurement tools. This is especially important when aiming to understand the role of hyperreflexia during functional movements where the biomechanical inputs are multiple and changing

    Pine cone scale-inspired motile origami

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    Stimuli-sensitive hydrogels have received attention because of their potential applications in various fields. Stimuli-directed motion offers many practical applications, such as in drug delivery systems and actuators. Directed motion of asymmetric hydrogels has long been designed; however, few studies have investigated the motion control of symmetric hydrogels. We designed a pine cone scale-inspired movable temperature-sensitive symmetric hydrogel that contains Fe3O4. Alignment of Fe3O4 along the magnetic force is key in motion control in which Fe3O4 acts like fibers in a pine cone scale. Although a homogeneous temperature-sensitive hydrogel cannot respond to a temperature gradient, the Fe3O4-containing hydrogel demonstrates considerable bending motion. Varying degrees and directions of motion are easily facilitated by controlling the amount and alignment angle of the Fe3O4. The shape of the hydrogel layer also influences the morphological structure. This study introduced facile and low-cost methods to control various bending motions. These results can be applied to many fields of engineering, including industrial engineering.111Ysciescopu

    Western men and Eastern arts: The significance of Eastern martial arts disciplines in British men's narratives of masculinity

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    Previous Western sociological research on Eastern martial arts has identified a tension between ‘traditional’ Eastern forms of practice and ‘modernized’ Western methods of training and competition. In particular, the ‘sportization’ of Eastern styles, where combat-centred arts based upon moral philosophies have transformed more or less into competitive activities following Western models of rationalized sport, has been an important theme. However, it is also suggested that Eastern martial arts hold special significance in the West for their seemingly esoteric nature. In this regard, such martial arts are considered significant because they are not ‘sports’, but rather disciplines, with fairly different connotations for practitioners. Drawing on interview data, this paper explores how Western practitioners of Eastern martial arts articulate this difference, principally by examining the place of martial artistry in British men's narratives of masculinity. Comparing themselves favourably to assumed, typical visions of Western sporting masculinity, such men draw upon the imagined uniqueness of their martial arts to construct a sense of moral superiority over other men. In so doing, they contribute to a rejection of what they believe to be ‘mainstream’ sporting Western masculinity, thus indicating the role that ‘alternative’ visions of physical culture can play in men's active constructions of gender
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