Comparison of Data Collection and Methods for the Approximation of Streambed Thermal Properties

When approximating heat transfer through a streambed, an understanding of the thermal properties of the sediments is essential (e.g., thermal conductivity, specific heat capacity, and density). Even though considerable research has been completed in this field, little has been done to establish appropriate standard data collection approaches or to compare modeling methods for approximating these properties. Three mixture models were selected for comparison against each other and against a bed conduction model (SEDMOD). Typical data collection approaches were implemented for use in the mixture models while numerous data collection approaches were employed for use within SEDMOD. Sediment samples were taken from the streambed to estimate the necessary parameters for the mixture models (e.g., sediment volume, density, porosity, etc.) and to identify the minerals present. To yield more accurate estimates of the thermal properties from SEDMOD, methods of obtaining sediment temperature profiles representing the influences of conduction only were developed through the use of a steel cylinder and different capping materials (e.g., using geo-fabric or aluminum). In comparison to laboratory measurements of the thermal properties, it was found that the mixture model that provided the best estimates of the thermal properties was a volume weighted average. The method that best isolated conductive heating from advective heating was the steel cylinder with an aluminum cap. Using this data to calibrate SEDMOD yielded thermal diffusivity values most similar to the laboratory measurements. Due to its ability to estimate both thermal diffusivity and reproduce sediment temperature profiles, SEDMOD is recommended in combination with the aluminum isolation technique

The Reverse Galeal Hinge Flap: Another Valuable Technique in the Repair of Scalp Defects Extending to the Calvarium

Over the last 30 years, the estimated incidence of nonmelanoma skin cancer (NMSC) has increased from 300,000 to greater than 2 million cases. Approximately 15% of these cancers occur on the scalp.1 Given the increasing incidence of NMSC and their predilection for the scalp, the demand for scalp repairs will continue to rise. It is important that the dermatologic surgeon is equipped to manage these cases, in particular defects that extend to the bone.The repair of large scalp defects extending to the calvarium is especially challenging for several reasons. The primary closure of any large scalp wound is complicated by the relative inelasticity of scalp tissue and the convexity of the scalp. Rotation flaps are the mainstay technique of re-approximating large scalp wounds but are often unable to completely close very large defects.2 Skin grafts can also be used to cover wounds primarily or in conjunction with other closure techniques.2 However, when scalp defects extend to the bone, the poor vascularity of the osseous tissue severely limits both skin grafting and xenografting. Various approaches to making exposed bone more suitable for grafting have been described in the recent literature, and these techniques and their limitations will be briefly discussed.3–5 The authors will also present two cases that outline a simple method of re-establishing a vascular bed on exposed bone using a reverse galeal hinge flap

Attributing decadal climate variability in coastal sea-level trends

Decadal sea-level variability masks longer-term changes due to natural and anthropogenic drivers in short-duration records and increases uncertainty in trend and acceleration estimates. When making regional coastal management and adaptation decisions, it is important to understand the drivers of these changes to account for periods of reduced or enhanced sea-level change. The variance in decadal sea-level trends about the global mean is quantified and mapped around the global coastlines of the Atlantic, Pacific, and Indian oceans from historical CMIP6 runs and a high-resolution ocean model forced by reanalysis data. We reconstruct coastal, sea-level trends via linear relationships with climate mode and oceanographic indices. Using this approach, more than one-third of the variability in decadal sea-level trends can be explained by climate indices at 24.6 % to 73.1 % of grid cells located within 25 km of a coast in the Atlantic, Pacific, and Indian oceans. At 10.9 % of the world's coastline, climate variability explains over two-thirds of the decadal sea-level trend. By investigating the steric, manometric, and gravitational components of sea-level trend independently, it is apparent that much of the coastal ocean variability is dominated by the manometric signal, the consequence of the open-ocean steric signal propagating onto the continental shelf. Additionally, decadal variability in the gravitational, rotational, and solid-Earth deformation (GRD) signal should not be ignored in the total. There are locations such as the Persian Gulf and African west coast where decadal sea-level variability is historically small that are susceptible to future changes in hydrology and/or ice mass changes that drive intensified regional GRD sea-level change above the global mean. The magnitude of variance explainable by climate modes quantified in this study indicates an enhanced uncertainty in projections of short- to mid-term regional sea-level trend

Compressive properties of additively manufactured materials compared to foams traditionally used for blunt force trauma protection

The aim of this study is to test currently available additive manufacturing (AM) materials against those used in personal protective clothing (PPC) in sport for blunt force trauma (BFT) protection in sport. Compression was identified as the primary mode of deflection during BFT therefore compression testing was chosen. Compressive stiffness and energy of AM polymers & rubber like materials were compared to those of traditional foam materials. This data will be used demonstrate the difference in behaviour between these materials and those used in AM during compression. Polymer and rubber like materials from three different AM processes were compared to three different foam materials in three different densities. Rubberlike materials absorbed the most energy while polymer samples absorbed very little. Some foam materials absorbed quantities of energy comparable to those absorbed by the rubber-like materials, however, they did so over a greater strain range

Genome-wide Profiling of RNA splicing in prostate tumor from RNA-seq data using virtual microarrays

BACKGROUND: Second generation RNA sequencing technology (RNA-seq) offers the potential to interrogate genome-wide differential RNA splicing in cancer. However, since short RNA reads spanning spliced junctions cannot be mapped contiguously onto to the chromosomes, there is a need for methods to profile splicing from RNA-seq data. Before the invent of RNA-seq technologies, microarrays containing probe sequences representing exon-exon junctions of known genes have been used to hybridize cellular RNAs for measuring context-specific differential splicing. Here, we extend this approach to detect tumor-specific splicing in prostate cancer from a RNA-seq dataset. METHOD: A database, SPEventH, representing probe sequences of under a million non-redundant splice events in human is created with exon-exon junctions of optimized length for use as virtual microarray. SPEventH is used to map tens of millions of reads from matched tumor-normal samples from ten individuals with prostate cancer. Differential counts of reads mapped to each event from tumor and matched normal is used to identify statistically significant tumor-specific splice events in prostate. RESULTS: We find sixty-one (61) splice events that are differentially expressed with a p-value of less than 0.0001 and a fold change of greater than 1.5 in prostate tumor compared to the respective matched normal samples. Interestingly, the only evidence, EST (BF372485), in the public database for one of the tumor-specific splice event joining one of the intron in KLK3 gene to an intron in KLK2, is also derived from prostate tumor-tissue. Also, the 765 events with a p-value of less than 0.001 is shown to cluster all twenty samples in a context-specific fashion with few exceptions stemming from low coverage of samples. CONCLUSIONS: We demonstrate that virtual microarray experiments using a non-redundant database of splice events in human is both efficient and sensitive way to profile genome-wide splicing in biological samples and to detect tumor-specific splicing signatures in datasets from RNA-seq technologies. The signature from the large number of splice events that could cluster tumor and matched-normal samples into two tight separate clusters, suggests that differential splicing is yet another RNA phenotype, alongside gene expression and SNPs, that can be exploited for tumor stratification

The Transient Sea Level response to external forcing in CMIP6 models

Earth is warming and sea levels are rising as land-based ice is lost to melt, and oceans expand due to accumulation of heat. The pace of ice loss and steric expansion is linked to the intensity of warming. How much faster sea level will rise as climate warms is, however, highly uncertain and difficult to model. Here, we quantify the transient sea level sensitivity (TSLS) of the sea level budget in both models and observations. Models show little change in sensitivity to warming between the first and second half of the 21st century for most contributors. The exception is glaciers and ice caps (GIC) that have a greater sensitivity pre-2050 (2.8±0.4 mm/yr/K) compared to later (0.7±0.1 mm/yr/K). We attribute this change to the short response time of glaciers and their changing area over time. Model sensitivities of steric expansion (1.5±0.2 mm/yr/K), and Greenland Ice Sheet mass loss (0.8±0.2 mm/yr/K) are greater than, but still compatible with, corresponding estimates from historical data (1.4±0.5 mm/yr/K and 0.4±0.2 mm/yr/K). Antarctic Ice Sheet (AIS) models tends to show lower rates of sea level rise with warming (-0.0±0.3 mm/yr/K) in contrast to historical estimates (0.4±0.2 mm/yr/K). This apparent low bias in AIS sensitivity is only partly able to account for a similar low bias identified in the sensitivity of GMSL excluding GIC (3.1±0.4 mm/yr/K vs 2.3±0.4 mm/yr/K). The balance temperature, where sea level rise is zero, lies close to the pre-industrial value, implying that sea level rise can only be mitigated by substantial global cooling

Energy coupling in short pulse laser solid interactions and its impact for space debris removal

Significant advances have been made over the last decade to improve the performance, efficiency, and contrast of high peak and average power laser systems, driven by their use in a wide variety of fields, from the industrial to the scientific. As the contrast of the lasers has improved, interactions with contrasts of 1012 are now routinely undertaken. At such high contrasts, there is negligible preplasma formation and the ionized surface layer created by subpicosecond-duration pulses typically forms a highly reflective "plasma mirror" capable of reflecting between 70% and 90% of the incident energy. Although such interactions are of significant interest for applications such as harmonic source production and to enable the underlying physics to be studied, their low absorption can limit their usefulness for applications such as space debris removal