Effective grain size distribution analysis for interpretation of tidal–deltaic facies: West Bengal Sundarbans

Research over the past two decades on the Holocene sediments from the tide dominated west side of the lower Ganges delta has focussed on constraining the sedimentary environment through grain size distributions (GSD). GSD has traditionally been assessed through the use of probability density function (PDF) methods (e.g. log-normal, log skew-Laplace functions), but these approaches do not acknowledge the compositional nature of the data, which may compromise outcomes in lithofacies interpretations. The use of PDF approaches in GSD analysis poses a series of challenges for the development of lithofacies models, such as equifinal distribution coefficients and obscuring the empirical data variability. In this study a methodological framework for characterising GSD is presented through compositional data analysis (CODA) plus a multivariate statistical framework. This provides a statistically robust analysis of the fine tidal estuary sediments from the West Bengal Sundarbans, relative to alternative PDF approaches

Younger Dryas glaciers and climate in the Mourne Mountains, Northern Ireland

Here, we present evidence to suggest that the Mourne Mountains, Northern Ireland, were last occupied by glaciers during the Younger Dryas Stadial. The margins of these glaciers are marked by moraines, chronologically constrained to the Younger Dryas by Schmidt hammer exposure dating. Reconstructions indicate that these glaciers had equilibrium-line altitudes (ELAs) ranging from 356 ± 33 m (a.s.l.) to 570 ± 9 m (a.s.l.), with a mean of 475 ± 36 m (a.s.l.). ELAs rise from west to east, probably reflecting the contribution of windblown snow and ice to the accumulation of Younger Dryas glaciers in the western Mournes. Taking this into consideration, a mean ‘climatic’ ELA of 529 ± 4 m (a.s.l.) is calculated for the mountains as a whole. Assuming a mean annual sea level air temperature of −8 °C, and an annual temperature range of 34 °C, degree-day modelling suggests that during the Younger Dryas, accumulation at the ‘climatic’ ELA of glaciers in the Mournes was 846–990 mm a−1. This suggests increased aridity, relative to present, and is consistent with other parts of NW Europe, where reduced precipitation alongside notable cooling is thought to reflect increased North Atlantic sea ice extent during the Younger Dryas.</p

Augmentation cystoplasty and extracellular matrix scaffolds: an ex vivo comparative study with autogenous detubularised Ileum

Background: Augmentation cystoplasty (AC) with autogenous ileum remains the current gold standard surgical treatment for many patients with end-stage bladder disease. However, the presence of mucus-secreting epithelium within the bladder is associated with debilitating long-term complications. Currently, decellularised biological materials derived from porcine extracellular matrix (ECM) are under investigation as potential augmentation scaffolds. Important biomechanical limitations of ECMs are decreased bladder capacity and poor compliance after implantation. Methodology/Principal Findings: In the present ex vivo study a novel concept was investigated where a two-fold increase in ECM scaffold surface-area relative to the resected ileal segment was compared in ovine bladder models after AC. Results showed that bladder capacity increased by 4064% and 37611% at 10 mmHg and compliance by 40.464% and 39.766% (DP = 0–10 mmHg) after AC with ileum and porcine urinary bladder matrix (UBM) respectively (p,0.05). Comparative assessment between ileum and UBM demonstrated no significant differences in bladder capacity or compliance increases after AC (p.0.05). Conclusions: These findings may have important clinical implications as metabolic, infective and malignant complications precipitated by mucus-secreting epithelium are potentially avoided after augmentation with ECM scaffolds

Augmentation Cystoplasty and Extracellular Matrix Scaffolds: An Ex Vivo Comparative Study with

Background: Augmentation cystoplasty (AC) with autogenous ileum remains the current gold standard surgical treatment for many patients with end-stage bladder disease. However, the presence of mucus-secreting epithelium within the bladder is associated with debilitating long-term complications. Currently, decellularised biological materials derived from porcine extracellular matrix (ECM) are under investigation as potential augmentation scaffolds. Important biomechanical limitations of ECMs are decreased bladder capacity and poor compliance after implantation. Methodology/Principal Findings: In the present ex vivo study a novel concept was investigated where a two-fold increase in ECM scaffold surface-area relative to the resected ileal segment was compared in ovine bladder models after AC. Results showed that bladder capacity increased by 4064 % and 37611 % at 10 mmHg and compliance by 40.464 % and 39.766% (DP = 0–10 mmHg) after AC with ileum and porcine urinary bladder matrix (UBM) respectively (p,0.05). Comparative assessment between ileum and UBM demonstrated no significant differences in bladder capacity or compliance increases after AC (p.0.05). Conclusions: These findings may have important clinical implications as metabolic, infective and malignant complications precipitated by mucus-secreting epithelium are potentially avoided after augmentation with ECM scaffolds

Comparative illustration of bladder capacity (ml) at baseline and after AC with ileum (A) and UBM (B).

<p>AC, augmentation cystoplasty.</p

Bladder capacity characteristics before and after AC with ileum (5×5 cm) at increasing pressures.

<p>AC, augmentation cystoplasty.</p><p>Volumetric increases after ileocystoplasty ranged from 51±9 ml at 2 mmHg to 96±13 ml at 10 mmHg (*p<0.01, n = 6).</p