Ground-penetrating radar surveys and ice volume estimates of Wedel Jarlsberg Land glaciers, Svalbard

We present volume calculations, with detailed error estimates, for eight glaciers on Wedel Jarlsberg Land, southern Spitsbergen, Svalbard, and compare them to those obtained from area-volume scaling relationships. The volume estimates are based upon a dense net of GPR-retrieved ice thickness data collected over several field campaigns spanning the period 2004-2011.

Ice volume estimates from ground-penetrating radar surveys, Wedel Jarlsberg Land glaciers, Svalbard

We present ground-penetrating radar (GPR)—based volume calculations, with associated error estimates, for eight glaciers on Wedel Jarlsberg Land, southwestern Spitsbergen, Svalbard, and compare them with those obtained from volume-area scaling relationships. The volume estimates are based upon GPR ice-thickness data collected during the period 2004–2013. The total area and volume of the ensemble are 502.91 ± 18.60 km2 and 91.91 ± 3.12 km3, respectively. The individual areas, volumes, and average ice thickness lie within 0.37–140.99 km2, 0.01–31.98 km3, and 28–227 m, respectively, with a maximum recorded ice thickness of 619 ± 13 m on Austre Torellbreen. To estimate the ice volume of unsurveyed tributary glaciers, we combine polynomial cross-sections with a function providing the best fit to the measured ice thickness along the center line of a collection of 22 surveyed tributaries. For the time-to-depth conversion of GPR data, we test the use of a glacierwide constant radio-wave velocity chosen on the basis of local or regional common midpoint measurements, versus the use of distinct velocities for the firn, cold ice, and temperate ice layers, concluding that the corresponding volume calculations agree with each other within their error bounds.

Structure–activity analysis of buforin II, a histone H2A-derived antimicrobial peptide: The proline hinge is responsible for the cell-penetrating ability of buforin II

Buforin II is a 21-aa potent antimicrobial peptide that forms, in a hydrophobic medium, an amphipathic structure consisting of an N-terminal random coil region (residues 1–4), an extended helical region (residues 5–10), a hinge (residue 11), and a C-terminal regular α-helical region (residues 12–21). To elucidate the structural features of buforin II that are required for its potent antimicrobial activity, we synthesized a series of N- and C-terminally truncated or amino acid-substituted synthetic buforin II analogs and examined their antimicrobial activity and mechanism of action. Deletion of the N-terminal random coil region increased the antibacterial activity ≈2-fold, but further N-terminal truncation yielded peptide analogs with progressively decreasing activity. Removal of four amino acids from the C-terminal end of buforin II resulted in a complete loss of antimicrobial activity. The substitution of leucine for the proline hinge decreased significantly the antimicrobial activity. Confocal fluorescence microscopic studies showed that buforin II analogs with a proline hinge penetrated the cell membrane without permeabilization and accumulated in the cytoplasm. However, removal of the proline hinge abrogated the ability of the peptide to enter cells, and buforin II analogs without a proline hinge localized on the cell surface, permeabilizing the cell membrane. In addition, the cell-penetrating efficiency of buforin II and its truncated analogs, which depended on the α-helical content of the peptides, correlated linearly with their antimicrobial potency. Our results demonstrate clearly that the proline hinge is responsible for the cell-penetrating ability of buforin II, and the cell-penetrating efficiency determines the antimicrobial potency of the peptide.

Chronic myeloid leukemia gene therapy delivered by cell penetrating peptides : from bench to clinic

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Lamellar keratoplasty in the dog;

Investigations made at the New York State Veterinary College.

An inquiry into the process of nature in repairing injuries of the intestines: illustrating the treatment of penetrating wounds and strangulated hernia.

Mode of access: Internet.

Radiations and living cells; an introduction to radiation biology, in which the action of penetrating radiations on the living cells is described, with special reference to the effect on cell division in human tissues.

Mode of access: Internet.

Locating a strand of the Seattle Fault Zone in southeast Seattle, Washington through topographic analysis, borehole analysis and ground penetrating radar

Contributing to the evaluation of seismic hazards, a previously unmapped strand of the Seattle Fault Zone (SFZ), cutting across the southwest side of Lake Washington and southeast Seattle, is located and characterized on the basis of bathymetry, borehole logs, and ground penetrating radar (GPR). Previous geologic mapping and geophysical analysis of the Seattle area have generally mapped the locations of some strands of the SFZ, though a complete and accurate understanding of locations of all individual strands of the fault system is still incomplete. A bathymetric scarp-like feature and co-linear aeromagnetic anomaly lineament defined the extent of the study area. A 2-dimensional lithology cross-section was constructed using six boreholes, chosen from suitable boreholes in the study area. In addition, two GPR transects, oblique to the proposed fault trend, served to identify physical differences in subsurface materials. The proposed fault trace follows the previously mapped contact between the Oligocene Blakeley Formation and Quaternary deposits, and topographic changes in slope. GPR profiles in Seward Park and across the proposed fault location show the contact between the Blakeley Formation and unconsolidated glacial deposits, but it does not constrain an offset. However, north-dipping beds in the Blakely Formation are consistent with previous interpretations of P-wave seismic profiles on Mercer Island and Bellevue, Washington. The profiles show the mapped location of the aeromagnetic lineament in Lake Washington and the inferred location of the steeply-dipping, high-amplitude bedrock reflector, representing a fault strand. This north-dipping reflector is likely the same feature identified in my analysis. I characterize the strand as a splay fault, antithetic to the frontal fault of the SFZ. This new fault may pose a geologic hazard to the region.

Perforated corneal hydrops treated with sulfur hexafluoride (SF6) gas and tissue adhesive

Purpose: To report a case of a perforated acute hydrops in a mentally retarded patient that was successfully managed with intracameral sulfur hexafluoride gas and cyanoacrylate tissue adhesive. Methods: Interventional case report. Results: A 14-year-old mentally retarded male patient with keratoconus presented with a perforated acute hydrops. A bandage contact lens was applied. However, following a large emesis 2 days later, the aqueous leak worsened with shallowing of the anterior chamber. Under general anesthesia, sulfur hexafluoride was injected to reform the anterior chamber and cyanoacrylate tissue adhesive was applied to the perforated site and covered by a bandage contact lens and temporary tarsorrhaphy. A follow-up examination at 1 month showed a formed anterior chamber with tissue adhesive in situ and no aqueous leak. Conclusions: The successful use of intracameral sulfur hexafluoride and tissue adhesive in the management of perforated acute hydrops may avoid emergency tectonic penetrating keratoplasty and reduce potential complications in the poorly cooperative patient.

Fitting an MSD (Mini Scleral Design) rigid contact lens in advanced keratoconus with INTACS

Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients. © 2011 British Contact Lens Association.

Geophysical Analysis of a Central Florida Karst Terrain using Light Detection and Ranging (LIDAR) and Ground Penetrating Radar (GPR) Derived Surfaces

Airborne LIDAR (Light Detecting and Ranging) is a relatively new technique that rapidly and accurately measures micro-topographic features. This study compares topography derived from LIDAR with subsurface karst structures mapped in 3-dimensions with ground penetrating radar (GPR). Over 500 km of LIDAR data were collected in 1995 by the NASA ATM instrument. The LIDAR data was processed and analyzed to identify closed depressions. A GPR survey was then conducted at a 200 by 600 m site to determine if the target features are associated with buried karst structures. The GPR survey resolved two major depressions in the top of a clay rich layer at ~10m depth. These features are interpreted as buried dolines and are associated spatially with subtle (< 1m) trough-like depressions in the topography resolved from the LIDAR data. This suggests that airborne LIDAR may be a useful tool for indirectly detecting subsurface features associated with sinkhole hazard.