The effect of incipient presbyopia on the correspondence between accommodation and vergence

Purpose: To investigate the accommodation-convergence relationship during the incipient phase of presbyopia. The study aimed to differentiate between the current theories of presbyopia and to explore the mechanisms by which the oculomotor system compensates for the change in the accommodation-convergence relationship contingent on a declining amplitude of accommodation. Methods: Using a Canon R-1 open-view autorefractor and a haploscope device, measurements were made of the stimulus and response accommodative convergence/accommodation ratios and the convergence accommodation/convergence ratio of 28 subjects aged 35-45 years at the commencement of the study. Amplitude of accommodation was assessed using a push-down technique. The measurements were repeated at 4-monthly intervals over a 2-year period. Results: The results showed that with the decline in the amplitude of accommodation there is an increase in the accommodative convergence response per unit of accommodative response and a decrease in the convergence accommodation response per unit of convergence. Conclusions: The results of this study fail to support the Hess-Gullstrand theory of presbyopia in that the ciliary muscle effort required to produce a unit change in accommodation increases, rather than stays constant, with age. Data show that the near vision response is limited to the maximum vergence response that can be tolerated and, despite being within the amplitude of accommodation, a stimulus may still appear blurred because the vergence component determines the proportion of available accommodation utilised during near vision.

Correspondence between muscle motion and EMG activity during whole body vibration

The aim of this study is to highlight the relation between muscle motion and electromyographyc activity during whole body vibration. This treatment is accounted for eliciting a reflex muscle activity in response to vibratory stimulation. Simultaneous recordings from quadriceps Rectus Femoris EMG and 3D muscle accelerations on fifteen subjects undergoing vibration treatments were collected. In our study vibrations were delivered via a sinusoidal oscillating platform at different frequencies (10-45 Hz), with a constant amplitude. Muscle motion was estimated by processing accelerometer data. Displacements revealed a mechanical resonant-like behaviour of the muscle; resonance frequencies and dumping factors depended on subject. Large EMG motion artifacts were removed using sharp notch filters centred at the vibration frequency and its superior harmonics. RMS values of artifact-free EMG were found correlated to the actual muscle displacement. The results were in accordance to the hypothesis of a proprioceptive response during vibration treatment. Nevertheless, motion artifacts produced an overestimation of muscle activity, therefore its removal was essential. © 2009 Springer Berlin Heidelberg.

Mathematical competence for information visualization by correspondence analysis methods

Report published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, May, 2016

Katalónia a következő független állam Európában? (Will Catalonia be the next independent state?)

A Katalóniában tapasztalható függetlenségi törekvések nem minősülnek csupán spanyol belügynek, komoly uniós és nemzetközi jogi vonatkozással bírnak. Különösen érdekes megvizsgálni, hogy egyes elemzők hogyan közelítik meg a potenciális függetlenedés közgazdasági összefüggéseit, előnyeit és hátrányait. A téma személyesen is érint, mivel 2012 júliusa és 2013 januárja között a barcelonai Universitat Abat Oliba CEU egyetem vendégoktatója és kutatója voltam, így első kézből tapasztaltam a téma érzékenységét. _____ The independence of Catalonia is not just simple Spanish “internal affair”, since it has serious international and European legal aspects. It is very interesting to analyse the different approaches of the parties and experts about the economic pros and cons of the potential independence. The topic is affecting me personally; because I was guest professor and researcher of the Universitat Abat Oliba CEU in Barcelona in a turbulent period from July 2012 until January 2013, so I could experience the sensitiveness of the subject.

A note on the axiomatization of the Nash equilibrium correspondence

A new axiomatization of the Nash equilibrium correspondence for n-person games based on independence of irrelevant strategies is given. Using a flexible general model, it is proved that the Nash equilibrium correspondence is the only solution to satisfy the axioms of non-emptiness, weak one-person rationality, independence of irrelevant strategies and converse independence of irrelevant strategies on the class of subgames of a fixed finite n-person game which admit at least one Nash equilibrium. It is also shown that these axioms are logically independent.

Correspondence of historic salinity fluctuations in Florida Bay, USA, to atmospheric variability and anthropogenic changes

Florida Bay is a highly dynamic estuary that exhibits wide natural fluctuations in salinity due to changes in the balance of precipitation, evaporation and freshwater runoff from the mainland. Rapid and large-scale modification of freshwater flow and construction of transportation conduits throughout the Florida Keys during the late nineteenth and twentieth centuries reshaped water circulation and salinity patterns across the ecosystem. In order to determine long-term patterns in salinity variation across the Florida Bay estuary, we used a diatom-based salinity transfer function to infer salinity within 3.27 ppt root mean square error of prediction from diatom assemblages from four ~130 year old sediment records. Sites were distributed along a gradient of exposure to anthropogenic shifts in the watershed and salinity. Precipitation was found to be the primary driver influencing salinity fluctuations over the entire record, but watershed modifications on the mainland and in the Florida Keys during the late-1800s and 1900s were the most likely cause of significant shifts in baseline salinity. The timing of these shifts in the salinity baseline varies across the Bay: that of the northeastern coring location coincides with the construction of the Florida Overseas Railway (AD 1906–1916), while that of the east-central coring location coincides with the drainage of Lake Okeechobee (AD 1881–1894). Subsequent decreases occurring after the 1960s (east-central region) and early 1980s (southwestern region) correspond to increases in freshwater delivered through water control structures in the 1950s–1970s and again in the 1980s. Concomitant increases in salinity in the northeastern and south-central regions of the Bay in the mid-1960s correspond to an extensive drought period and the occurrence of three major hurricanes, while the drop in the early 1970s could not be related to any natural event. This paper provides information about major factors influencing salinity conditions in Florida Bay in the past and quantitative estimates of the pre- and post-South Florida watershed modification salinity levels in different regions of the Bay. This information should be useful for environmental managers in setting restoration goals for the marine ecosystems in South Florida, especially for Florida Bay.

Correspondence course for travel counsellors : hospitality industry project

The purpose of this paper is to produce a travel counselling course which could be subscribed to by students from Canada and abroad, which, upon completion, would qualify them to work in a travel agency.

Lesbian Herstory historians and archivists

General note: Title and date provided by Bettye Lane.

Ink Under the Fingernails: Making Print in Nineteenth-Century Mexico City

This dissertation examines Mexico City’s material politics of print—the central actors engaged in making print, their activities and relationships, and the legal, business, and social dimensions of production—across the nineteenth century. Inside urban printshops, a socially diverse group of men ranging from manual laborers to educated editors collaborated to make the printed items that fueled political debates and partisan struggles in the new republic. By investigating how print was produced, regulated, and consumed, this dissertation argues that printers shaped some of the most pressing conflicts that marked Mexico’s first formative century: over freedom of expression, the role of religion in government, and the emergence of liberalism. Printers shaped debates not only because they issued texts that fueled elite politics but precisely because they operated at the nexus where new liberal guarantees like freedom of the press and intellectual property intersected with politics and patronage, the regulatory efforts of the emerging state, and the harsh realities of a post-colonial economy.

Historians of Mexico have typically approached print as a vehicle for texts written by elites, which they argue contributed to the development of a national public sphere or print culture in spite of low literacy levels. By shifting the focus to print’s production, my work instead reveals that a range of urban residents—from prominent printshop owners to government ministers to street vendors—produced, engaged, and deployed printed items in contests unfolding in the urban environment. As print increasingly functioned as a political weapon in the decades after independence, print production itself became an arena in struggles over the emerging contours of politics and state formation, even as printing technologies remained relatively unchanged over time.

This work examines previously unexplored archival documents, including official correspondence, legal cases, business transactions, and printshop labor records, to shed new light on Mexico City printers’ interactions with the emerging national government, and reveal the degree to which heated ideological debates emerged intertwined with the most basic concerns over the tangible practices of print. By delving into the rich social and cultural world of printing—described by intellectuals and workers alike in memoirs, fiction, caricatures and periodicals— it also considers how printers’ particular status straddling elite and working worlds led them to challenge boundaries drawn by elites that separated manual and intellectual labors. Finally, this study engages the full range of printed documents made in Mexico City printshops not just as texts but also as objects with particular visual and material qualities whose uses and meanings were shaped not only by emergent republicanism but also by powerful colonial legacies that generated ambivalent attitudes towards print’s transformative power.

Conjuring Canadas: Historians and the Quest to Define a Canadian Nation and its Past, 1920-1967

This dissertation examines the various ways in which Canadian historical researchers confronted the “Canada question,” namely the challenge of defining the basis of a unified national community. In doing so, it follows the scholarship and activities of a network of historians and intellectuals centred on the Canadian Historical Review, a quarterly publication founded in 1920. This study examines their scholarship with the aim of identifying not only the various solutions they posed to the problem, but also the philosophical undercurrents that informed their reasoning in the process. It also traces the rise of a rival network in the Revue d’histoire de l’Amérique française, a French-language historical publication founded in 1947 that by its very existence posed a significant challenge to the definition of the nation at the core of the Canadian Historical Review. This dissertation argues that the network bound together by the Review was engaged in a hegemonic project, one that sought to present a particular definition of Canada through a historical narrative that rested upon a liberal logic. Yet the greatest sustained challenge they faced in this endeavour emerged from Francophone historical scholars, who, although proposing vastly different Canadas to those imagined at the Canadian Historical Review, came under the sway of a number of liberal currents of thought as well. A detailed summary of the key traits of these liberal Canadas is found in the conclusion.