327 research outputs found
review of paediatric liver resections in Johannesburg: Experiences and preferred technique
Background. Liver resections are widely performed in paediatric surgery. Many techniques exist to achieve vascular control, minimise bleeding and complete the parenchymal division.Methods. We retrospectively reviewed all liver resections performed in the Department of Paediatric Surgery at our institution between January 2005 and June 2012. Data pertaining to basic demographics, indications for surgery, parenchymal transection techniques, morbidity, mortality and histology were collated.Results. Twenty-one resections were performed in children aged 6 weeks - 11 years; 18 for malignant liver disease (including 9 hepatoblastomas), and 3 for benign disease. We describe 1 perioperative mortality secondary to torsion of the liver remnant, and no surgical morbidity. Three cases underwent total hepatic vascular exclusion with sharp parenchymal transection. The remaining patients underwent selective vascular inflow and outflow control using the Cavitron Ultra Sonic Aspirator and Harmonic Scalpel to divide the parenchyma.Conclusion. Care for these patients should be multidisciplinary.High-volume units and access to liver transplantation offer optimal results. No technique is proven superior to the ‘clamp crush’ technique of parenchymal transection. Knowledge of hepatic anatomy is key to minimising morbidity, and surgeons should be familiar with and have the flexibility to use all techniques of vascular control
A new methodology to simulate subglacial deformation of water-saturated granular material
The dynamics of glaciers are to a large degree governed by processes
operating at the iceābed interface, and one of the primary
mechanisms of glacier flow over soft unconsolidated sediments is
subglacial deformation. However, it has proven difficult to
constrain the mechanical response of subglacial sediment to the
shear stress of an overriding glacier. In this study, we present
a new methodology designed to simulate subglacial deformation using
a coupled numerical model for computational experiments on
grain-fluid mixtures. The granular phase is simulated on a per-grain
basis by the discrete element method. The pore water is modeled as
a compressible Newtonian fluid without inertia. The numerical
approach allows close monitoring of the internal behavior under
a range of conditions.
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Our computational experiments support the findings of previous studies
where the rheology of a slowly deforming water-saturated granular bed in the
steady state generally conforms to the rate-independent plastic rheology.
Before this so-called critical state, deformation is in many cases accompanied
by volumetric changes as grain rearrangement in active shear zones changes the
local porosity. For previously consolidated beds porosity
increases can cause local pore-pressure decline, dependent on till
permeability and shear rate. We observe that the pore-water pressure reduction
strengthens inter-granular contacts, which results in increased shear strength
of the granular material. In contrast, weakening takes place when shear
deformation causes consolidation of dilated sediments or during rapid fabric
development. Both processes of strengthening and weakening depend inversely on
the sediment permeability and are transient phenomena tied to the porosity
changes during the early stages of shear.
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We find that the transient strengthening and weakening in turn influences the
distribution of shear strain in the granular bed. Dilatant strengthening has
the ability to distribute strain during early deformation to large depths, if
sediment dilatancy causes the water pressure at the iceābed interface to
decline. Oppositely, if the iceābed interface is hydrologically stable the
strengthening process is minimal and instead causes shallow deformation. The
depth of deformation in subglacial beds thus seems to be governed by not only
local grain and pore-water feedbacks but also larger-scale hydrological
properties at the ice base
Dealing with a traumatic past: the victim hearings of the South African truth and reconciliation commission and their reconciliation discourse
In the final years of the twentieth and the beginning of the twenty-first century, there has been a worldwide tendency to approach conflict resolution from a restorative rather than from a retributive perspective. The South African Truth and Reconciliation Commission (TRC), with its principle of 'amnesty for truth' was a turning point. Based on my discursive research of the TRC victim hearings, I would argue that it was on a discursive level in particular that the Truth Commission has exerted/is still exerting a long-lasting impact on South African society. In this article, three of these features will be highlighted and illustrated: firstly, the TRC provided a discursive forum for thousands of ordinary citizens. Secondly, by means of testimonies from apartheid victims and perpetrators, the TRC composed an officially recognised archive of the apartheid past. Thirdly, the reconciliation discourse created at the TRC victim hearings formed a template for talking about a traumatic past, and it opened up the debate on reconciliation. By discussing these three features and their social impact, it will become clear that the way in which the apartheid past was remembered at the victim hearings seemed to have been determined, not so much by political concerns, but mainly by social needs
The role of age and mode of delivery in the STEPS intervention: a longitudinal pilot-study in treatment of posttraumatic stress symptoms in Danish survivors of sexual assault
Background: The STEPS programme has been succesfully implemented as a group-based treatment of trauma symptoms after rape for adolescents. The STEPS intervention was translated from Dutch to Danish and offered to adults in addition to adolescents as well as an individual intervention in addition to a group-based intervention at a Danish Centre for Rape Victims through 2011 to 2014. The programme was translated from Dutch to Danish and expanded to adults in addition to adolescents as well as to an individual intervention in addition to a group-based intervention at a Danish Centre for Rape Victims through 2011 to 2014. Objective: The present study observesĀ development in trauma symptoms and ICD-11 diagnostic status during an adapted version of the intervention programme āSTEPSā for survivors of sexual assault. Methods: A prospective uncontrolled study was conducted, monitoring symptoms of posttraumatic stress and other trauma-related symptomatology before treatment, after treatment and at 6 and 12 months' follow up for 103 referrals receiving individual or group-based STEPS. Tentative diagnoses of posttraumatic stress disorder (PTSD) and complex PTSD were assigned to participants according to the ICD-11 to observe the development in diagnostic status across time, and multilevel modelling was used to assess the development of symptom severity and to assess the moderating effect of age-group and mode of delivery. Results: A loglinear function representing large and statistically significant decline in symptomatology over time provided the best fit for all measures of trauma-related symptomatology. The decline was not moderated by age-group or mode of intervention. Dropout rates were independent of mode of intervention and age. Conclusion: The adaption of the STEPS programme to adults and as an individual intervention is feasible and maintains effect sizes comparable to those observed in the original intervention. Further research using randomized controlled trials is needed to ascribe the observed effect to the STEPS programme
The racist bodily imaginary: the image of the body-in-pieces in (post)apartheid culture
This paper outlines a reoccurring motif within the racist imaginary of (post)apartheid culture: the black body-in-pieces. This disturbing visual idiom is approached from three conceptual perspectives. By linking ideas prevalent in Frantz Fanonās description of colonial racism with psychoanalytic concepts such as Lacanās notion of the corps morcelĆ©, the paper offers, firstly, an account of the black body-in-pieces as fantasmatic preoccupation of the (post)apartheid imaginary. The role of such images is approached, secondly, through the lens of affect theory which eschews a representational āreadingā of such images in favour of attention to their asignifying intensities and the role they play in effectively constituting such bodies. Lastly, Judith Butlerās discussion of war photography and the conditions of grievability introduces an ethical dimension to the discussion and helps draw attention to the unsavory relations of enjoyment occasioned by such images
First report of the presence of hepatitis E virus in Scottish harvested shellfish purchased at retail level
Lichens facilitate seedling recruitment in alpine heath
Abstract Questions How do mat thickness, physical structure and allelopathic properties of terricolous mat-forming lichens affect recruitment of vascular plants in dwarf-shrub and lichen heath vegetation?. Location The mountains of Dovrefjell, central Norway. Methods In autumn, seeds of ten vascular plant species were collected and sown in a common garden experiment with mats of six lichen species and bare-soil controls as experimental treatments. We recorded growing season soil temperature and moisture, and seedling recruitment and growth after one year. The effect of lichen secondary compounds on germination was tested in a growth chamber experiment and compared to the lichen-plant interactions detected under field conditions. Results The lichen mats buffered extreme soil temperatures and soil drying in dry weather, with soils below the thickest mats (Cladonia stellaris and C. rangiferina) experiencing the lowest temperature fluctuations. Seedling recruitment and seedling growth in the field and seed germination in the lab were species-specific. Seedling recruitment rates were overall higher within lichen mats than on bare soil, but the c. 6.5 cm thick mats of C. stellaris reduced recruitment of many species. The lab experiment suggested no overall strong effect of lichen allelopathy on seed germination, and effects on seed germination were only moderately correlated with the lichen-plant interactions observed for seedling recruitment in the field. Conclusions In harsh environments like alpine dwarf-shrub and lichen heaths, the presence of lichens and the resulting amelioration of the microclimate seems more important for vascular plant recruitment than are allelopathic effects often reported in lab experiments. We might therefore expect most terricolous lichens, depending on the plant species in focus, to facilitate rather than hamper the early stages of plant recruitment into lichen-dominated arctic-alpine heath vegetation. This article is protected by copyright. All rights reserved.Peer reviewe
Investigation of the properties of fully reacted unstoichiometric polydimethylsiloxane networks and their extracted network fractions
B cell immune profiles in dysbiotic vermiform appendixes of pancreatic cancer patients
Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest solid tumors and is resistant to immunotherapy. B cells play an essential role in PDAC progression and immune responses, both locally and systemically. Moreover, increasing evidence suggests that microbial compositions inside the tumor, as well as in the oral cavity and the gut, are important factors in shaping the PDAC immune landscape. However, the gut-associated lymphoid tissue (GALT) has not previously been explored in PDAC patients. In this study, we analyzed healthy vermiform appendix (VA) from 20 patients with PDAC and 32 patients with colon diseases by gene expression immune profiling, flow cytometry analysis, and microbiome sequencing. We show that the VA GALT of PDAC patients exhibits markers of increased inflammation and cytotoxic cell activity. In contrast, B cell function is decreased in PDAC VA GALT based on gene expression profiling; B cells express significantly fewer MHC class II surface receptors, whereas plasma cells express the immune checkpoint molecule HLA-G. Additionally, the vermiform appendix microbiome of PDAC patients is enriched with Klebsiella pneumoniae, Bifidobacterium animalis, and Adlercreutzia equolifaciens, while certain commensals are depleted. Our findings may suggest impaired B cell function within the GALT of PDAC patients, which could potentially be linked to microbial dysbiosis. Additional investigations are imperative to validate our observations and explore these potential targets of future therapies.</p
B cell immune profiles in dysbiotic vermiform appendixes of pancreatic cancer patients
Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest solid tumors and is resistant to immunotherapy. B cells play an essential role in PDAC progression and immune responses, both locally and systemically. Moreover, increasing evidence suggests that microbial compositions inside the tumor, as well as in the oral cavity and the gut, are important factors in shaping the PDAC immune landscape. However, the gut-associated lymphoid tissue (GALT) has not previously been explored in PDAC patients. In this study, we analyzed healthy vermiform appendix (VA) from 20 patients with PDAC and 32 patients with colon diseases by gene expression immune profiling, flow cytometry analysis, and microbiome sequencing. We show that the VA GALT of PDAC patients exhibits markers of increased inflammation and cytotoxic cell activity. In contrast, B cell function is decreased in PDAC VA GALT based on gene expression profiling; B cells express significantly fewer MHC class II surface receptors, whereas plasma cells express the immune checkpoint molecule HLA-G. Additionally, the vermiform appendix microbiome of PDAC patients is enriched with Klebsiella pneumoniae, Bifidobacterium animalis, and Adlercreutzia equolifaciens, while certain commensals are depleted. Our findings may suggest impaired B cell function within the GALT of PDAC patients, which could potentially be linked to microbial dysbiosis. Additional investigations are imperative to validate our observations and explore these potential targets of future therapies.</p
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