Imaging of the human fundus in the clinical setting:past present and future

The human fundus is a complex structure that can be easily visualized and the world of ophthalmology is going through a golden era of new and exciting fundus imaging techniques; recent advances in technology have allowed a significant improvement in the imaging modalities clinicians have available to formulate a diagnostic and treatment plan for the patient, but there is constant on-going work to improve current technology and create new ideas in order to gather as much information as possible from the human fundus. In this article we shall summarize the imaging techniques available in the standard medical retina clinic (i.e. not limited to the research lab) and delineate the technologies that we believe will have a significant impact on the way clinicians will assess retinal and choroidal pathology in the not too distant future.

Parabolic optical pulses under the action of the third-order dispersion

Recent developments in nonlinear optics reveal an interesting class of pulses with a parabolic intensity profile in the energy-containing core and a linear frequency chirp that can propagate in a fiber with normal group-velocity dispersion. Parabolic pulses propagate in a stable selfsimilar manner, holding certain relations (scaling) between pulse power, width, and chirp parameter. In the additional presence of linear amplification, they enjoy the remarkable property of representing a common asymptotic state (or attractor) for arbitrary initial conditions. Analytically, self-similar (SS) parabolic pulses can be found as asymptotic, approximate solutions of the nonlinear Schr¨odinger equation (NLSE) with gain in the semi-classical (largeamplitude/small-dispersion) limit. By analogy with the well-known stable dynamics of solitary waves - solitons, these SS parabolic pulses have come to be known as similaritons. In practical fiber systems, inherent third-order dispersion (TOD) in the fiber always introduces a certain degree of asymmetry in the structure of the propagating pulse, eventually leading to pulse break-up. To date, there is no analytic theory of parabolic pulses under the action of TOD. Here, we develop aWKB perturbation analysis that describes the effect of weak TOD on the parabolic pulse solution of the NLSE in a fiber gain medium. The induced perturbation in phase and amplitude can be found to any order. The theoretical model predicts with sufficient accuracy the pulse structural changes induced by TOD, which are observed through direct numerical NLSE simulations.

Existence and Uniqueness of Solutions for Partial Differential-Functional Equations of the First Order with Deviating Argument of the Derivative of Unknown Function

We consider the existence and uniqueness problem for partial differential-functional equations of the first order with the initial condition for which the right-hand side depends on the derivative of unknown function with deviating argument.

On the Equivalence of the Riemann-Liouville and the Caputo Fractional Order Derivatives in Modeling of Linear Viscoelastic Materials

Mathematics Subject Classification: 26A33

Foveation time measure in Congenital Nystagmus through second order approximation of the slow phases

Congenital Nystagmus (CN) is an ocular-motor disorder characterised by involuntary, conjugated ocular oscillations, and its pathogenesis is still unknown. The pathology is de fined as "congenital" from the onset time of its arise which could be at birth or in the first months of life. Visual acuity in CN subjects is often diminished due to nystagmus continuous oscillations, mainly on the horizontal plane, which disturb image fixation on the retina. However, during short periods in which eye velocity slows down while the target image is placed onto the fovea (called foveation intervals) the image of a given target can still be stable, allowing a subject to reach a higher visual acuity. In CN subjects, visual acuity is usually assessed both using typical measurement techniques (e.g. Landolt C test) and with eye movement recording in different gaze positions. The offline study of eye movement recordings allows physicians to analyse nystagmus main features such as waveform shape, amplitude and frequency and to compute estimated visual acuity predictors. This analytical functions estimates the best corrected visual acuity using foveation time and foveation position variability, hence a reliable estimation of this two parameters is a fundamental factor in assessing visual acuity. This work aims to enhance the foveation time estimation in CN eye movement recording, computing a second order approximation of the slow phase components of nystag-mus oscillations. About 19 infraredoculographic eye-movement recordings from 10 CN subjects were acquired and the visual acuity assessed with an acuity predictor was compared to the one measured in primary position. Results suggest that visual acuity measurements based on foveation time estimation obtained from interpolated data are closer to value obtained during Landolt C tests. © 2010 IEEE.

Classification of the Maximal Subsemigroups of the Semigroup of all Partial Order-Preserving Transformations

Илинка А. Димитрова, Цветелина Н. Младенова - Моноида P Tn от всички частични преобразования върху едно n-елементно множество относно операцията композиция на преобразования е изучаван в различни аспекти от редица автори. Едно частично преобразование α се нарича запазващо наредбата, ако от x ≤ y следва, че xα ≤ yα за всяко x, y от дефиниционното множество на α. Обект на разглеждане в настоящата работа е моноида P On състоящ се от всички частични запазващи наредбата преобразования. Очевидно P On е под-моноид на P Tn. Направена е пълна класификация на максималните подполугрупи на моноида P On. Доказано е, че съществуват пет различни вида максимални подполугрупи на разглеждания моноид. Броят на всички максимални подполугрупи на POn е точно 2^n + 2n − 2.

Explaining turn of the year order flow imbalance

The paper provides evidence of a turn of the year effect in the order flow imbalance of both retail and institutional investors. In December there is net selling pressure which is reversed in January. We examine high frequency intraday order flow information and find that the changes in order flow imbalance between December and January are related to firm risk factors and characteristics. We find that retail order flow imbalances are associated with a wide range of risk characteristics including beta, illiquidity and unsystematic risk. Imbalances in institutional order flow are associated with only a small number of risk variables. We show that these order flow changes are important because risk premiums are elevated in January. Our results are robust to the effects of decimalization.

The Asymptotic Behaviour of the First Eigenvalue of Linear Second-Order Elliptic Equations in Divergente Form

2000 Mathematics Subject Classification: 35J70, 35P15.

Bayesian and Frequentist Two-Sample Predictions of the Inverse Weibull Model Based on Generalized Order Statistics

2000 Mathematics Subject Classification: 62E16,62F15, 62H12, 62M20.

"Belonging” in the gentrified Golden Horn/Halic neighbourhoods of Istanbul

Mainstream gentrification research predominantly examines experiences and motivations of the middle-class gentrifier groups, while overlooking experiences of non-gentrifying groups including the impact of in situ local processes on gentrification itself. In this paper, I discuss gentrification, neighbourhood belonging and spatial distribution of class in Istanbul by examining patterns of belonging both of gentrifiers and non-gentrifying groups in historic neighbourhoods of the Golden Horn/Halic. I use multiple correspondence analysis (MCA), a methodology rarely used in gentrification research, to explore social and symbolic borders between these two groups. I show how gentrification leads to spatial clustering by creating exclusionary practices and eroding social cohesion, and illuminate divisions that are inscribed into the physical space of the neighbourhood.

Az ajánlati könyv statisztikai tulajdonságai (Statistical properties of the limit order book)

A pénzügyi modellek jelentős része feltételezi a piacok hatékony működését. Ennek következtében számos tudományos kutatás központi témája volt a piacok hatékonyságának tesztelése és ennek igazolása, esetleg cáfolata. Ezen próbálkozások azonban mind a mai napig eredménytelenül zárultak. A tesztelések nyomán a kutatások a termékek áralakulásából indultak ki, és a hozamokat ezen keresztül elemezték. Az elmúlt években azonban a fókusz átterelődött az árak alakulásáról egy elemibb tényezőre, az ajánlati könyvre. Ugyanis végső soron az ajánlatvezérelt piacokon az árakat az ajánlati könyvbe benyújtott megbízások alakulása fogja meghatározni. Mivel a tőzsdék jelentős része ajánlatvezérelt piacként működik, ezért érdemesnek tartották a kutatók, hogy inkább az ajánlati könyv alakulásának statisztikai jellemzőit elemezzék, hátha az eredményre vezet, és sikerül közelebb jutni a hatékony piacok elméletének igazolásához vagy cáfolatához. Jelen tanulmány célja az, hogy az eddig megjelent tudományos kutatások alapján ismertesse az ajánlati könyv alapvető statisztikai tulajdonságait, és rávilágítson arra: mindez valójában hozzájárult-e a hatékony piacok elméletének igazolásához? ______ Most of the fi nancial models assume that markets are effi cient. As a result, numerous scientifi c researchers were focused on testing the effi cient market hypothesis, and tried to prove, or deny it. However, all these attempts are still unsuccessful. During these researches, the analyses of the effi cient market hypothesis were based on the price evolution of a certain asset, and through this the returns were examined. In the recent years the research interest has changed, and instead of analyzing the returns, a more primary factor got into focus, namely the limit order book. The reason is that on order driven markets the prices and the order sizes in the limit order book infl uence the price evolution on the market. Since a notable number of stock markets operate as an order driven market, the researchers thought that it worth analyzing the statistical properties of the limit order book, because maybe it will get us closer to the proof of the effi cient market hypothesis. The purpose of this study is to summarize the statistical properties of the limit order book, based on the scientifi c works published so far. The study would like to highlight whether these studies contributed to the proof or disproof of the effi cient market hypothesis.

Obama és az új világrend a gazdasági válság tükrében (Obama and the new world order in light of the economic crisis)

Napjainkban a nemzetközi kapcsolatok meghatározó jelensége a gazdasági világválság, amelynek kezelése kapcsán egyre gyakrabban merül fel a politikusok és az elemzők szóhasználatában az „új világrend” fogalma. ____ In treating the current global economic crisis, politicians and analysts increasingly refer to a "new world order". The paper examines this concept, its different meanings and historical evolution, as well as the role it plays in the rhetoric of the Obamaadministration.

The analysis of the resort timesharing industry in order to determine the industry's familiarity with timesharing and the industry's conception of the present and future effects of timesharing

The purpose of the study is to examine the impactof the timesharing concept on the resort industry in order to determine the industry's familiarity with timesharing and the industry's conception of the present and future effects of timesharing. The study utilizes two methods of research, primarydata and secondary data, to examine the concept of timesharing. This section includes information on the different forms of timesharing, the legal aspects, the marketing, management, finance and future of timesharing in order to educate the public about the concept. The primary data takes the form of a survey thatquestions hotel/motel operators in the Fort Lauderdale Beach area to determine their attitudes towards the impact of timesharing on the resort industy.

The international legal thought of Carl Schmitt : towards a critique of the contemporary international order

The aim of the thesis is to develop a critique of current liberal conceptualizations of international order. In order to conduct this critique, this thesis revisits the arguments first put forth by the German legal and political theorist Carl Schmitt. Schmitt conceptualizes a tripartite unity between law, order, and place. This unity, established at the constituent moment of land-appropriation, forms a concrete nomos, which subsequently creates the contours of the legal and political order. The establishment of the concrete order is necessarily the construction of a territorial boundary that designates an inside and an outside of the polity. By speaking of a nomos of the earth, Schmitt globalized this understanding of concrete order by looking at the various historical developments that created a "line" between the concrete applicability of interstate norms and a region where the exceptional situation prevails. The critique presented in this thesis is concerned with the lack of concrete boundary conditions within the current international legal order. It is argued that this lack of a well-defined boundary condition is what results in extreme forms of violence that were traditionally bracketed.