XUV Frequency Combs via Femtosecond Enhancement Cavities

We review the current state of tabletop extreme ultraviolet (XUV) sources based on high harmonic generation (HHG) in femtosecond enhancement cavities (fsEC). Recent developments have enabled generation of high photon flux (1014 photons/sec) in the XUV, at high repetition rates (>50 MHz) and spanning the spectral region from 40 nm - 120 nm. This level of performance has enabled precision spectroscopy with XUV frequency combs and promises further applications in XUV spectroscopic and photoemission studies. We discuss the theory of operation and experimental details of the fsEC and XUV generation based on HHG, including current technical challenges to increasing the photon flux and maximum photon energy produced by this type of system. Current and future applications for these sources are also discussed.Comment: invited review article, 38 page

Fermion Helicity Flip Induced by Torsion Field

We show that in theories of gravitation with torsion the helicity of fermion particles is not conserved and we calculate the probability of spin flip, which is related to the anti-symmetric part of affine connection. Some cosmological consequences are discussed.Comment: 6 pages, to appear in Europhysics Letter

Advances, limitations and future perspectives in the diagnosis and management of dry eye in Sjogren's syndrome

Primary Sjogren's syndrome is a complex systemic autoimmune disorder that primarily affects exocrine glands such as the lacrimal glands. Dry eye disease is one of the most prevalent complications of Sjogren's syndrome, affecting most patients. It significantly impairs quality of life and management is often difficult and unsatisfactory, in part due to weak correlation between symptoms and signs and poor recognition of the three main subtypes aqueous-deficient, evaporative and neuropathic dry eye. This review provides an overview of key aspects of dry eye disease, such as its multifactorial aetiology and recent insights into pathophysiology. The uses and pitfalls of commonly-used diagnostic tests for dry eye are reviewed, as well as the increasing number of new imaging technologies and biomarkers to refine diagnosis. There are many current and emerging treatment options for dry eye in Sjogren's syndrome, but high-level evidence of efficacy is mostly lacking, as are evidence-based treatment algorithms. All these aspects make the management of dry eye in Sjogren's syndrome challenging

Spinless Matter in Transposed-Equi-Affine Theory of Gravity

We derive and discus the equations of motion for spinless matter: relativistic spinless scalar fields, particles and fluids in the recently proposed by A. Saa model of gravity with covariantly constant volume with respect to the transposed connection in Einstein-Cartan spaces. A new interpretation of this theory as a theory with variable Plank "constant" is suggested. We show that the consistency of the semiclassical limit of the wave equation and classical motion dictates a new definite universal interaction of torsion with massive fields.Comment: 29 pages, latex, no figures. New Section on semiclassical limit of wave equation added; old references rearranged; new references, remarks, comments, and acknowledgments added; typos correcte

Advances, limitations and future perspectives in the diagnosis and management of dry eye in Sjogren's syndrome

Primary Sjogren's syndrome is a complex systemic autoimmune disorder that primarily affects exocrine glands such as the lacrimal glands. Dry eye disease is one of the most prevalent complications of Sjogren's syndrome, affecting most patients. It significantly impairs quality of life and management is often difficult and unsatisfactory, in part due to weak correlation between symptoms and signs and poor recognition of the three main subtypes aqueous-deficient, evaporative and neuropathic dry eye. This review provides an overview of key aspects of dry eye disease, such as its multifactorial aetiology and recent insights into pathophysiology. The uses and pitfalls of commonly-used diagnostic tests for dry eye are reviewed, as well as the increasing number of new imaging technologies and biomarkers to refine diagnosis. There are many current and emerging treatment options for dry eye in Sjogren's syndrome, but high-level evidence of efficacy is mostly lacking, as are evidence-based treatment algorithms. All these aspects make the management of dry eye in Sjogren's syndrome challenging

Preferential Association of Segment Blocks in Polyurethane Nanocomposites

Submitted to MacromoleculesControlling the level of dispersion of silicate layers in polymer matrices through intermolecular interactions and exploiting these interactions to enhance thermomechanical behavior are key challenges in the field of polymer nanocomposites. In this investigation, unmodified Laponite platelets are dispersed in a segmented polyurethane containing polar, hydrophilic soft segments and a hydrophobic hard segment using a novel solvent exchange method and compared to polyurethane nanocomposites containing more hydrophobic hard and soft domains. It was determined that the silicate layers were preferentially, but not exclusively, attracted to the hydrophilic, polar soft domains. An apparent micro-phase segregated morphology was observed in transmission electron microscopy for this system, revealing regions of exfoliation and intercalation. According to polarizing optical microscopy, strain-induced alignment is inhibited for this polyurethane nanocomposite, which is reflected in dramatic reductions in tensile strength and ultimate extensibility. In comparison, the Laponite discs appear to be preferentially, but not exclusively, embedded to the hard domains in the segmented polyurethanes containing more hydrophobic hard and soft domains. Exfoliation of the clay platelets leads to enhanced modulus and toughness without a reduction in extensibility. This study provides clues for exploiting silicate-polymer interactions to tune material properties without chemical modification.Institute for Soldier Nanotechnology (ISN) at MI

Two new species of Prosorhynchoides (Digenea: Bucephalidae) from Tylosurus crocodilus (Belonidae) from the great barrier reef and French Polynesia

We surveyed 14 individuals of Tylosurus crocodilus Péron & Lesueur 1821 (Belonidae) collected from the waters around Lizard Island and Heron Island, Great Barrier Reef, Queensland, Australia, and the waters around Moorea, French Polynesia. We describe two new species of bucephaline trematodes from them, Prosorhynchoides galaktionovi n. sp. and P. kohnae n. sp. They are morphologically distinct from existing Prosorhynchoides spp., with molecular data from 28S and ITS-2 ribosomal DNA, as well as cox1 mitochondrial DNA, further supporting our morphological findings. Neither species has been observed in other belonid fishes. The new species fall into the clade of species of Prosorhynchoides from belonids previously identified in Australian waters. These findings strengthen the observation that groups of bucephaline species have radiated, at least in part, in tight association with host taxa. There are now five species of Prosorhynchoides known from two belonid species in Australian waters. We, therefore, predict further richness in the nine other belonid species present