Targeted Perfusion Therapy in Spinal Cord Trauma.

We review state-of-the-art monitoring techniques for acute, severe traumatic spinal cord injury (TSCI) to facilitate targeted perfusion of the injured cord rather than applying universal mean arterial pressure targets. Key concepts are discussed such as intraspinal pressure and spinal cord perfusion pressure (SCPP) at the injury site, respectively, analogous to intracranial pressure and cerebral perfusion pressure for traumatic brain injury. The concept of spinal cord autoregulation is introduced and quantified using spinal pressure reactivity index (sPRx), which is analogous to pressure reactivity index for traumatic brain injury. The U-shaped relationship between sPRx and SCPP defines the optimum SCPP as the SCPP that minimizes sPRx (i.e., maximizes autoregulation), and suggests that not only ischemia but also hyperemia at the injury site may be detrimental. The observation that optimum SCPP varies between patients and temporally in each patient supports individualized management. We discuss multimodality monitoring, which revealed strong correlations between SCPP and injury site metabolism (tissue glucose, lactate, pyruvate, glutamate, glycerol), monitored by surface microdialysis. Evidence is presented that the dura is a major, but unappreciated, cause of spinal cord compression after TSCI; we thus propose expansion duroplasty as a novel treatment. Monitoring spinal cord blood flow at the injury site has revealed novel phenomena, e.g., 3 distinct blood flow patterns, local steal, and diastolic ischemia. We conclude that monitoring from the injured spinal cord in the intensive care unit is a safe technique that appears to enable optimized and individualized spinal cord perfusion

Refugees, trauma and adversity-activated development

The nature of the refugee phenomenon is examined and the position of mental health professionals is located in relation to it. The various uses of the word 'trauma' are explored and its application to the refugee context is examined. It is proposed that refugees' response to adversity is not limited to being traumatized but includes resilience and Adversity-Activated Development (AAD). Particular emphasis is given to the distinction between resilience and AAD. The usefulness of the 'Trauma Grid' in the therapeutic process with refugees is also discussed. The Trauma Grid avoids global impressions and enables a more comprehensive and systematic way of identifying the individual refugee's functioning in the context of different levels, i.e. individual, family, community and society/culture. Finally, I discuss implications for therapeutic work with refugees

Patching DFT, T-duality and Gerbes

We clarify the role of the dual coordinates as described from the perspectives of the Buscher T-duality rules and Double Field Theory. We show that the T-duality angular dual coordinates cannot be identified with Double Field Theory dual coordinates in any of the proposals that have been made in the literature for patching the doubled spaces. In particular, we show with explicit examples that the T-duality angular dual coordinates can have non-trivial transition functions over a spacetime and that their identification with the Double Field Theory dual coordinates is in conflict with proposals in which the latter remain inert under the patching of the B-field. We then demonstrate that the Double Field Theory coordinates can be identified with some C-space coordinates and that the T-dual spaces of a spacetime are subspaces of the gerbe in C-space. The construction provides a description of both the local $O(d,d)$ symmetry and the T-dual spaces of spacetime.Comment: minor changes, references adde

Superstring dualities and p-brane bound states

We show that the M-theory/IIA and IIA/IIB superstring dualities together with the diffeomorphism invariance of the underlying theories require the presence of certain p-brane bound states in IIA and IIB superstring theories preserving 1/2 of the spacetime supersymmetry. We then confirm the existence of IIA and IIB supergravity solutions having the appropriate p-brane bound states interpretation.Comment: 21 pages, Phyzzx, Minor corrections, Version that will appear in Nucl. Phys.

AdS4 backgrounds with N>16 supersymmetries in 10 and 11 dimensions

We explore all warped $AdS_4\times_w M^{D-4}$ backgrounds with the most general allowed fluxes that preserve more than 16 supersymmetries in $D=10$- and $11$-dimensional supergravities. After imposing the assumption that either the internal space $M^{D-4}$ is compact without boundary or the isometry algebra of the background decomposes into that of AdS$_4$ and that of $M^{D-4}$, we find that there are no such backgrounds in IIB supergravity. Similarly in IIA supergravity, there is a unique such background with 24 supersymmetries locally isometric to $AdS_4\times \mathbb{CP}^3$, and in $D=11$ supergravity all such backgrounds are locally isometric to the maximally supersymmetric $AdS_4\times S^7$ solution.Comment: 53 pages. v2: minor changes and references added. v3: typos corrected and minor footnote added, published versio

Collective Resistance as a Means to Healing. a Collective Narrative Participatory Project With Black and Ethnic Minority LGBT Refugee & Asylum-Seeking People

The number of people in exile is rising. Forced migrant populations often navigate treacherous journeys, experiences of losses, and hostile realities in reception countries. Black and Minority Ethnic (BME) Lesbian, Gay, Bisexual, and Transgender (LGBT) refugee and asylum-seeking people present with special psychological and socio-economico-political challenges; yet little is still known about how services can support their healing. Existing literature investigating resilience and wellbeing cartographies in this population is sparse and has neglected to examine collective understandings of resources, alongside the performative aspects of local resistances. Hoping to offer valuable insights into how we can all ethically stand by this population’s needs, this study endorsed a collective narrative participatory design, to explore collective ways of resisting oppression amongst BME LGBT refugee and asylum-seeking people, through concerning itself with how such stories can be constitutive of healing. A social constructionist epistemology was appropriated. Purposeful sampling procedures were pursued in collaboration with a London-based charitable organisation to locate suitable participants. Data comprised participants’ story-telling, as captured over two sequences: individual and collective. Story-telling was aided through the co-construction of a novel metaphor: ‘The Passport of Life’. ‘Narrative Analysis’ was employed for the processing of the data, the direction of which was co-shaped with participants. Findings indicate that participants’ (collective) story-telling is crafted as a site for resistances to emerge and be re-affirmed. Resistance pathways are inextricably linked to participants’ diverse subjectivities, reflecting respective opportunities and constraints. Participants’ narrativisation of their intersectional subjectivities mirrors their multiple contextual realities and is indicative of an ‘ever-becoming’ process that challenges the fixedness of borders and dominant western identity conventions. Healing is constituted as a dynamic process, bound by discursive and physical configurations of spaces of togetherness and belonging, which have re-definitional, hope-inducing, and social justice properties. The results also support the use of participatory, narrative, and creative means (e.g. metaphors) for expanding people’s (untold) stories and supporting opportunities for healing and social justice

Deformations of generalized calibrations and compact non-Kahler manifolds with vanishing first Chern class

We investigate the deformation theory of a class of generalized calibrations in Riemannian manifolds for which the tangent bundle has reduced structure group U(n), SU(n), G_2 and Spin(7). For this we use the property of the associated calibration form to be parallel with respect to a metric connection which may have non-vanishing torsion. In all these cases, we find that if there is a moduli space, then it is finite dimensional. We present various examples of generalized calibrations that include almost hermitian manifolds with structure group U(n) or SU(n), nearly parallel G_2 manifolds and group manifolds. We find that some Hopf fibrations are deformation families of generalized calibrations. In addition, we give sufficient conditions for a hermitian manifold (M,g,J) to admit Chern and Bismut connections with holonomy contained in SU(n). In particular we show that any connected sum of $k \geq 3$ copies of $S^3 \times S^3$ admits a hermitian structure for which the restricted holonomy of a Bismut connection is contained in SU(3).Comment: 43 pages, Latex, typos corrected, reference added in section

Twistor Spaces for QKT Manifolds

We find that the target space of two-dimensional (4,0) supersymmetric sigma models with torsion coupled to (4,0) supergravity is a QKT manifold, that is, a quaternionic K\"ahler manifold with torsion. We give four examples of geodesically complete QKT manifolds one of which is a generalisation of the LeBrun geometry. We then construct the twistor space associated with a QKT manifold and show that under certain conditions it is a K\"ahler manifold with a complex contact structure. We also show that, for every 4k-dimensional QKT manifold, there is an associated 4(k+1)-dimensional hyper-K\"ahler one.Comment: 25 pages, phyzz

Covariantly constant forms on torsionful geometries from world-sheet and spacetime perspectives

The symmetries of two-dimensional supersymmetric sigma models on target spaces with covariantly constant forms associated to special holonomy groups are analysed. It is shown that each pair of such forms gives rise to a new one, called a Nijenhuis form, and that there may be further reductions of the structure group. In many cases of interest there are also covariantly constant one-forms which also give rise to symmetries. These geometries are of interest in the context of heterotic supergravity solutions and the associated reductions are studied from a spacetime point of view via the Killing spinor equations.Comment: 33 pages, minor modifications, version published in JHE

Acute Spinal Cord Injury: Correlations and Causal Relations Between Intraspinal Pressure, Spinal Cord Perfusion Pressure, Lactate-to-Pyruvate Ratio, and Limb Power.

BACKGROUND/OBJECTIVE: We have recently developed monitoring from the injury site in patients with acute, severe traumatic spinal cord injuries to facilitate their management in the intensive care unit. This is analogous to monitoring from the brain in patients with traumatic brain injuries. This study aims to determine whether, after traumatic spinal cord injury, fluctuations in the monitored physiological, and metabolic parameters at the injury site are causally linked to changes in limb power. METHODS: This is an observational study of a cohort of adult patients with motor-incomplete spinal cord injuries, i.e., grade C American spinal injuries association Impairment Scale. A pressure probe and a microdialysis catheter were placed intradurally at the injury site. For up to a week after surgery, we monitored limb power, intraspinal pressure, spinal cord perfusion pressure, and tissue lactate-to-pyruvate ratio. We established correlations between these variables and performed Granger causality analysis. RESULTS: Nineteen patients, aged 22-70 years, were recruited. Motor score versus intraspinal pressure had exponential decay relation (intraspinal pressure rise to 20 mmHg was associated with drop of 11 motor points, but little drop in motor points as intraspinal pressure rose further, R2 = 0.98). Motor score versus spinal cord perfusion pressure (up to 110 mmHg) had linear relation (1.4 motor point rise/10 mmHg rise in spinal cord perfusion pressure, R2 = 0.96). Motor score versus lactate-to-pyruvate ratio (greater than 20) also had linear relation (0.8 motor score drop/10-point rise in lactate-to-pyruvate ratio, R2 = 0.92). Increased intraspinal pressure Granger-caused increase in lactate-to-pyruvate ratio, decrease in spinal cord perfusion, and decrease in motor score. Increased spinal cord perfusion Granger-caused decrease in lactate-to-pyruvate ratio and increase in motor score. Increased lactate-to-pyruvate ratio Granger-caused increase in intraspinal pressure, decrease in spinal cord perfusion, and decrease in motor score. Causality analysis also revealed multiple vicious cycles that amplify insults to the cord thus exacerbating cord damage. CONCLUSION: Monitoring intraspinal pressure, spinal cord perfusion pressure, lactate-to-pyruvate ratio, and intervening to normalize these parameters are likely to improve limb power