Case report: corrected bladder exstrophy - caesarean birth

We present a case of 26 yrs old Primigravida, who was presented at the antenatal clinic of Kenyatta National Hospital at 20 weeks gestation. She was a known case of congenital bladder exstrophy. Patient was diagnosed with bladder exstrophy at birth and underwent a total of 3 bladder surgeries, has had suprapubic catheter for the last 15 years and underwent vaginoplasty and vaginal dilatation for vaginal atresia, and she has conceived naturally

Corrected bladder exstrophy- Caesarean birth

Case Summary: We present a case of 26 yrs old Primigravida, who presented at the antenatal clinic of Kenyatta National Hospital at 20 weeks gestation, she was a known case of congenital bladder exstrophy. Patient was diagnosed with bladder exstrophy at birth and underwent a total of 3 bladder surgeries, has had suprapubic catheter for the last 15 years and underwent vaginoplasty and vaginal dilatation for vaginal atresia, and she has conceived naturally

The 8.2 ka cooling event caused by Laurentide ice saddle collapse

The 8.2 ka event was a period of abrupt cooling of 1–3 °C across large parts of the Northern Hemisphere, which lasted for about 160 yr. The original hypothesis for the cause of this event has been the outburst of the proglacial Lakes Agassiz and Ojibway. These drained into the Labrador Sea in ∼0.5–5 yr and slowed the Atlantic Meridional Overturning Circulation, thus cooling the North Atlantic region. However, climate models have not been able to reproduce the duration and magnitude of the cooling with this forcing without including additional centennial-length freshwater forcings, such as rerouting of continental runoff and ice sheet melt in combination with the lake release. Here, we show that instead of being caused by the lake outburst, the event could have been caused by accelerated melt from the collapsing ice saddle that linked domes over Hudson Bay in North America. We forced a General Circulation Model with time varying meltwater pulses (100–300 yr) that match observed sea level change, designed to represent the Hudson Bay ice saddle collapse. A 100 yr long pulse with a peak of 0.6 Sv produces a cooling in central Greenland that matches the 160 yr duration and 3 °C amplitude of the event recorded in ice cores. The simulation also reproduces the cooling pattern, amplitude and duration recorded in European Lake and North Atlantic sediment records. Such abrupt acceleration in ice melt would have been caused by surface melt feedbacks and marine ice sheet instability. These new realistic forcing scenarios provide a means to reconcile longstanding mismatches between proxy data and models, allowing for a better understanding of both the sensitivity of the climate models and processes and feedbacks in motion during the disintegration of continental ice sheets

A novel pathway for efficient characterisation of additively manufactured thermoplastic elastomers

Thermoplastic elastomers (TPE) are commonly used to fabricate structures for application in repeatable, energy absorption environments. The emergence of additive manufacturing (AM) means scope now exists to design and build complex TPE components that can mechanically outperform traditionally manufactured equivalents. The ability to efficiently characterize these new TPE AM materials is, however, a barrier preventing wider industrial uptake. This study aims to establish a novel pathway for efficiently characterizing materials used in transient, dynamic applications, to ultimately enable accurate finite element (FE) simulation. A laser sintered TPE powder was characterised by performing low, intermediate and high rate uniaxial tension tests, plus planar and equibiaxial loading states. These data demonstrated significantly different behaviour across strain rates and deformation modes, necessitating fit of an augmented hyperelastic and linear viscoelastic model. FE software was then used to calibrate material model coefficients, with their validity evaluated by comparing the simulated and experimental behaviour of the material in isolated (uniaxial tensile) and mixed modal (lattice-based impact) deformation states. Close correlation demonstrated this novel approach efficiently generated valid material model coefficients, removing a barrier to industry adopting these materials. This creates opportunity to exploit these new technologies for the design optimization and fabrication of high-performance component

Simulating the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk revision 3298)

Simulating the demise of the Laurentide Ice Sheet covering Hudson Bay in the Early Holocene (10–7 ka) is important for understanding the role of accelerated changes in ice sheet topography and melt in the 8.2 ka event, a century long cooling of the Northern Hemisphere by several degrees. Freshwater released from the ice sheet through a surface mass balance instability (known as the saddle collapse) has been suggested as a major forcing for the 8.2 ka event, but the temporal evolution of this pulse has not been constrained. Dynamical ice loss and marine interactions could have significantly accelerated the ice sheet demise, but simulating such processes requires computationally expensive models that are difficult to configure and are often impractical for simulating past ice sheets. Here, we developed an ice sheet model setup for studying the Laurentide Ice Sheet's Hudson Bay saddle collapse and the associated meltwater pulse in unprecedented detail using the BISICLES ice sheet model, an efficient marine ice sheet model of the latest generation which is capable of refinement to kilometre-scale resolutions and higher-order ice flow physics. The setup draws on previous efforts to model the deglaciation of the North American Ice Sheet for initialising the ice sheet temperature, recent ice sheet reconstructions for developing the topography of the region and ice sheet, and output from a general circulation model for a representation of the climatic forcing. The modelled deglaciation is in agreement with the reconstructed extent of the ice sheet, and the associated meltwater pulse has realistic timing. Furthermore, the peak magnitude of the modelled meltwater equivalent (0.07–0.13 Sv) is compatible with geological estimates of freshwater discharge through the Hudson Strait. The results demonstrate that while improved representations of the glacial dynamics and marine interactions are key for correctly simulating the pattern of Early Holocene ice sheet retreat, surface mass balance introduces by far the most uncertainty. The new model configuration presented here provides future opportunities to quantify the range of plausible amplitudes and durations of a Hudson Bay ice saddle collapse meltwater pulse and its role in forcing the 8.2 ka event

Encryption Modes with Almost Free Message Integrity

We define a new mode of operation for block encryption which in addition to assuring confidentiality also assures message integrity. In contrast, previously for message integrity a separate pass was required to compute a cryptographic message authentication code (MAC). The new mode of operation, called Integrity Aware CBC (IACBC), requires a total of m + log m block encryptions on a plaintext of length m blocks. The well known CBC (cipher block chaining) mode requires

Effective Mixing of Dissimilar Fluids in Asymmetric Confined Impinging Jets Mixers

The industrial applications of Confined Impinging Jets (CIJ) mixers typically involve the mixing of two dissimilar fluids. Previous fundamental studies on the flow dynamics in CIJ mixers have only reported mixing fluids with a viscosity ratio up to 2 in mixers with similar nozzle diameters. In this paper, the onset of a self-sustainable chaotic flow regime was visualised for mixing of dissimilar fluids with a viscosity ratio range from 2 to 9 and for chambers with different injector diameters. Experimental and numerical results show that CIJ mixing chambers are able to efficiently mix fluids with different viscosities. The two sufficient conditions to effectively mix in a chaotic flow regime are the operation above the critical Reynolds number defined by the more viscous fluid and the balance of jets that makes them imping at the mixing chamber axis