Intraocular Chemotherapy for Vitreoretinal Lymphoma: a review

© 2019 Royal Australian and New Zealand College of OphthalmologistsVitreoretinal lymphomas are rare ocular cancers, and the subset of primary central nervous system lymphomas that are based in the posterior eye. These tumours are challenging to treat, and today management generally involves a multispecialty team coordinating a treatment protocol that may include intraocular chemotherapy, ocular irradiation, systemic chemotherapy and/or autologous stem cell transplantation. The ophthalmologist has specific responsibility for the intraocular chemotherapy, which is delivered to the eye by intravitreal injection. The most commonly injected drugs are methotrexate—an anti‐metabolite—and rituximab—an anti‐human B cell monoclonal antibody. A range of intraocular chemotherapy treatment schedules have been described in the medical literature, although to date there have been no randomized clinical trials of these schedules. In this article, we review the development and current status of intraocular chemotherapy for vitreoretinal lymphoma

A new approach to spherically symmetric junction surfaces and the matching of FLRW regions

We investigate timelike junctions (with surface layer) between spherically symmetric solutions of the Einstein-field equation. In contrast to previous investigations this is done in a coordinate system in which the junction surface motion is absorbed in the metric, while all coordinates are continuous at the junction surface. The evolution equations for all relevant quantities are derived. We discuss the no-surface layer case (boundary surface) and study the behaviour for small surface energies. It is shown that one should expect cases in which the speed of light is reached within a finite proper time. We carefully discuss necessary and sufficient conditions for a possible matching of spherically symmetric sections. For timelike junctions between spherically symmetric space-time sections we show explicitly that the time component of the Lanczos equation always reduces to an identity (independently of the surface equation of state). The results are applied to the matching of FLRW models. We discuss `vacuum bubbles' and closed-open junctions in detail. As illustrations several numerical integration results are presented, some of them indicate that the junction surface can reach the speed of light within a finite time.Comment: new version - corrected boundary surface discussion, improved presentation, and corrected reference 22 pages, many figure

Neuromuscular fatigue and recovery after strenuous exercise depends on skeletal muscle size and stem cell characteristics

Hamstring muscle injury is highly prevalent in sports involving repeated maximal sprinting. Although neuromuscular fatigue is thought to be a risk factor, the mechanisms underlying the fatigue response to repeated maximal sprints are unclear. Here, we show that repeated maximal sprints induce neuromuscular fatigue accompanied with a prolonged strength loss in hamstring muscles. The immediate hamstring strength loss was linked to both central and peripheral fatigue, while prolonged strength loss was associated with indicators of muscle damage. The kinematic changes immediately after sprinting likely protected fatigued hamstrings from excess elongation stress, while larger hamstring muscle physiological cross-sectional area and lower myoblast:fibroblast ratio appeared to protect against fatigue/damage and improve muscle recovery within the first 48 h after sprinting. We have therefore identified novel mechanisms that likely regulate the fatigue/damage response and initial recovery following repeated maximal sprinting in humans.</p

Theory and simulation of quantum photovoltaic devices based on the non-equilibrium Green's function formalism

This article reviews the application of the non-equilibrium Green's function formalism to the simulation of novel photovoltaic devices utilizing quantum confinement effects in low dimensional absorber structures. It covers well-known aspects of the fundamental NEGF theory for a system of interacting electrons, photons and phonons with relevance for the simulation of optoelectronic devices and introduces at the same time new approaches to the theoretical description of the elementary processes of photovoltaic device operation, such as photogeneration via coherent excitonic absorption, phonon-mediated indirect optical transitions or non-radiative recombination via defect states. While the description of the theoretical framework is kept as general as possible, two specific prototypical quantum photovoltaic devices, a single quantum well photodiode and a silicon-oxide based superlattice absorber, are used to illustrated the kind of unique insight that numerical simulations based on the theory are able to provide.Comment: 20 pages, 10 figures; invited review pape

Invariant construction of solutions to Einstein's field equations - LRS perfect fluids II

The properties of LRS class II perfect fluid space-times are analyzed using the description of geometries in terms of the Riemann tensor and a finite number of its covariant derivatives. In this manner it is straightforward to obtain the plane and hyperbolic analogues to the spherical symmetric case. For spherically symmetric static models the set of equations is reduced to the Tolman-Oppenheimer-Volkoff equation only. Some new non-stationary and inhomogeneous solutions with shear, expansion, and acceleration of the fluid are presented. Among these are a class of temporally self-similar solutions with equation of state given by $p=(\gamma-1)\mu, 1<\gamma<2$, and a class of solutions characterized by $\sigma=-\Theta/6$. We give an example of geometry where the Riemann tensor and the Ricci rotation coefficients are not sufficient to give a complete description of the geometry. Using an extension of the method, we find the full metric in terms of curvature quantities.Comment: 24 pages, 1 figur

Territorial Self-Governance and Proportional Representation:Reducing the Risk of Territory-Centred Intrastate Violence

After decades of scholarship, there is still little agreement about the usefulness of territorial self-governance in managing territory-centred conflicts. We argue that the effectiveness of territorial self-governance as a tool of territory-centred conflict management increases when combined with a proportional representation (PR) electoral system for the national legislature in basically open political regimes, but not when combined with a parliamentary form of government at the centre. We propose that the combination of territorial self-governance and PR in at least minimally democratic regimes has most conflict-reducing potential, as both institutions follow a logic of widening the input side of representative politics. We find empirical support for this proposition using binary time-series cross-section analysis is found. Our findings highlight the need to consider not just the number but, more importantly, the type of power-sharing institutions that are combined with each other when looking for ways to reduce the risk of territory-centred intrastate violence

The underlying causes of military outsourcing in the USA and UK: bridging the persistent gap between ends, ways and means since the beginning of the Cold War

This article reappraises the two most-studied country cases of military outsourcing: the USA and the UK. It argues that the contemporary wave of military contracting stretches back to the beginning of the cold war and not only to the demobilisation of armies in the 1990s or the neoliberal reforms introduced since the 1980s. It traces the political, technological and ideational developments that laid the groundwork for these reforms and practices since the early cold war and account for its endurance today. Importantly, it argues that a persistent gap between strategic objectives and resources, i.e. the challenge to reconcile ends and means, is an underlying driver of military contracting in both countries. Contemporary contracting is thus most closely tied to military support functions in support of wider foreign and defence political objectives. Security services in either state may not have been outsourced so swiftly, if at all, without decades of experience in outsourcing military logistics functions and the resultant vehicles, processes and familiarities with public-private partnerships. The article thus provides a wider and deeper understanding of the drivers of contractualisation, thereby improving our understanding of both its historical trajectory and the determinants of its present and potential futures

Collapsing shear-free perfect fluid spheres with heat flow

A global view is given upon the study of collapsing shear-free perfect fluid spheres with heat flow. We apply a compact formalism, which simplifies the isotropy condition and the condition for conformal flatness. This formalism also presents the simplest possible version of the main junction condition, demonstrated explicitly for conformally flat and geodesic solutions. It gives the right functions to disentangle this condition into well known differential equations like those of Abel, Riccati, Bernoulli and the linear one. It yields an alternative derivation of the general solution with functionally dependent metric components. We bring together the results for static and time- dependent models to describe six generating functions of the general solution to the isotropy equation. Their common features and relations between them are elucidated. A general formula for separable solutions is given, incorporating collapse to a black hole or to a naked singularity.Comment: 26 page

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing.

Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage