Evidence for a perception memory continuum: an EEG study in a healthy population

In line with current memory theories of a perception-memory continuum along the ventral visual pathway, there is evidence that the specific profile of enhanced memory in special populations (e.g. synaesthesia) is based on increased perceptual sensitivity. The main goal of this study was to test in a more general population, if increased perceptual sensitivity is indeed associated with enhanced memory performance. We measured ERPs in response to simple perceptual stimuli biasing either the ventral or the dorsal route and established if perceptual sensitivity in response to ventrally (but not dorsally) processed stimuli is associated with visual short term memory performance in a change detection task. Preliminary results confirm the hypothesis and strengthen the assumption of a perceptual-memory-continuum.

Racial Disparities in Access to and Outcomes of Kidney Transplantation in Children, Adolescents, and Young Adults: Results From the ESPN/ERA-EDTA (European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association) Registry.

BACKGROUND Racial disparities in kidney transplantation in children have been found in the United States, but have not been studied before in Europe. STUDY DESIGN Cohort study. SETTING & PARTICIPANTS Data were derived from the ESPN/ERA-EDTA Registry, an international pediatric renal registry collecting data from 36 European countries. This analysis included 1,134 young patients (aged�����19 years) from 8 medium- to high-income countries who initiated renal replacement therapy (RRT) in 2006 to��2012. FACTOR Racial background. OUTCOMES & MEASUREMENTS Differences between racial groups in access to kidney transplantation, transplant survival, and overall survival on RRT were examined using Cox regression analysis while adjusting for age at RRT initiation, sex, and country of residence. RESULTS 868 (76.5%) patients were white; 59 (5.2%), black; 116 (10.2%), Asian; and 91 (8.0%), from other racial groups. After a median follow-up of 2.8 (range, 0.1-3.0) years, we found that black (HR, 0.49; 95% CI, 0.34-0.72) and Asian (HR, 0.54; 95% CI, 0.41-0.71) patients were less likely to receive a kidney transplant than white patients. These disparities persisted after adjustment for primary renal disease. Transplant survival rates were similar across racial groups. Asian patients had higher overall mortality risk on RRT compared with white patients (HR, 2.50; 95% CI, 1.14-5.49). Adjustment for primary kidney disease reduced the effect of Asian background, suggesting that part of the association may be explained by differences in the underlying kidney disease between racial groups. LIMITATIONS No data for socioeconomic status, blood group, and HLA profile. CONCLUSIONS We believe this is the first study examining racial differences in access to and outcomes of kidney transplantation in a large European population. We found important differences with less favorable outcomes for black and Asian patients. Further research is required to address the barriers to optimal treatment among racial minority groups.

The role of sensory neuron outgrowth in long-term sensitization of the tail-elicited tail-siphon withdrawal reflex of Aplysia

Neuronal outgrowth has been proposed in many systems as a mechanism underlying memory storage. For example, sensory neuron outgrowth is widely accepted as an underlying mechanism of long-term sensitization of defensive withdrawal reflexes in Aplysia. The hypothesis is that learning leads to outgrowth and consequently to the formation of new synapses, which in turn strengthen the neural circuit underlying the behavior. However, key experiments to test this hypothesis have never been performed. ^ Four days of sensitization training leads to outgrowth of siphon sensory neurons mediating the siphon-gill withdrawal response in Aplysia . We found that a similar training protocol produced robust outgrowth in tail sensory neurons mediating the tail siphon withdrawal reflex. In contrast, 1 day of training, which effectively induces long-term behavioral sensitization and synaptic facilitation, was not associated with neuronal outgrowth. Further examination of the effect of behavioral training protocols on sensory neuron outgrowth indicated that this structural modification is associated only with the most persistent forms of sensitization, and that the induction of these changes is dependent on the spacing of the training trials over multiple days. Therefore, we suggest that neuronal outgrowth is not a universal mechanism underlying long-term sensitization, but is involved only in the most persistent forms of the memory. ^ Sensory neuron outgrowth presumably contributes to long-term sensitization through formation of new synapses with follower motor neurons, but this hypothesis has never been directly tested. The contribution of outgrowth to long-term sensitization was assessed using confocal microscopy to examine sites of contact between physiologically connected pairs of sensory and motor neurons. Following 4 days of training, the strength of both the behavior and sensorimotor synapse and the number of appositions with follower neurons was enhanced only on the trained side of the animal. In contrast, outgrowth was induced on both sides of the animal, indicating that although sensory neuron outgrowth does appear to contribute to sensitization through the formation of new synapses, outgrowth alone is not sufficient to account for the effects of sensitization. This indicates that key regulatory steps are downstream from outgrowth, possibly in the targeting of new processes and activation of new synapses. ^

Salvaging Historic Shipwrecks

The salvage of historic shipwrecks involves a debate between profit-oriented salvagers, who wish to maximize profit, and archeologists, who wish to maximize historical value. We use a principal-agent model to derive the optimal reward scheme for salvagers, including a minimum duty of care in conducting the salvage operation. A review of U.S. and international law suggests that, while there is an emerging recognition of the need to devote greater care to salvaging those wrecks that are located, current doctrines provide inadequate incentives to locate historic wrecks in the first place.

Diagnosing the Prodromal State of Alzheimer's Disease

Mild Cognitive Impairment- Amnestic Subtype (MCIa) is a putative prodromal stage of Alzheimer���s Disease (AD) characterized by focal deficits in episodic verbal memory. Less is known about relative deficits in visuospatial learning, although there is ample evidence indicating involvement of the hippocampus in visuospatial learning, as well as hippocampal degeneration in early AD. The aim of this study was to better characterize the components of working memory dysfunction in people with MCIa to increase the ability to reliably diagnose this disease. Fifty-six elderly adults diagnosed with MCIa and 94 healthy elderly completed a hidden maze learning task. Results indicated similar functioning between groups on measures of reasoning, problem solving, and accuracy. However, MCIa subjects were less efficient at learning the hidden path, making more errors per second on average (Cohen���s d= -.78) and requiring a longer time to complete the maze (Cohen���s d=.77). The learning curve between the first two trials was four times as steep for healthy elderly compared to MCIa (slopes = 4.9 vs. 1.24, respectively), indicating that MCIa subjects exhibited relative difficulty in holding and making effective use of an internal spatial map in order to improve performance. Our results suggest that MCIa patients have focal deficits in visuospatial working memory, with relative preservation of functioning on other more global measures of cognitive functioning. This particular pattern of results may be specific to the amnestic variant of MCI.

STUDIES ON CHOLINERGIC FUNCTION AND MEMORY IN MICE (CHOLINOTOXINS, WORKING, REFERENCE MEMORY, RADIAL ARM MAZE)

Considerable evidence suggests that central cholinergic neurons participate in either acquisition, storage or retrieval of information. Experiments were designed to evaluate information processing in mice following either reversible or irreversible impairment in central cholinergic activity. The cholinergic receptor antagonists, atropine and methylatropine were used to reversibly inhibit cholinergic transmission. Irreversible impairment in central cholinergic function was achieved by central administration of the cholinergic-specific neurotoxins, N-ethyl-choline aziridinium (ECA) and N-ethyl-acetylcholine aziridinium (EACA).^ ECA and EACA appear to act by irreversible inhibition of high affinity choline uptake (proposed rate-limiting step in acetylcholine synthesis). Intraventricular administration of ECA or EACA produced persistent reduction in hippocampal choline acetyltransferase activity. Other neuronal systems and brain regions showed no evidence of toxicity.^ Mice treated with either ECA or EACA showed behavioral deficits associated with cholinergic dysfunction. Passive avoidance behavior was significantly impaired by cholinotoxin treatment. Radial arm maze performance was also significantly impaired in cholinotoxin-treated animals. Deficits in radial arm maze performance were transient, however, such that rapid and apparent complete behavioral recovery was seen during retention testing. The centrally active cholinergic receptor antagonist atropine also caused significant impairment in radial arm maze behavior, while equivalent doses of methylatropine were without effect.^ The relative effects of cholinotoxin and receptor antagonist treatment on short-term (working) memory and long-term (reference) memory in radial arm maze behavior were examined. Maze rotation studies indicated that there were at least two different response strategies which could result in accurate maze performance. One strategy involved the use of response algorithms and was considered to be a function of reference memory. Another strategy appeared to be primarily dependent on spatial working memory. However, all behavioral paradigms with multiple trails have reference memory requirements (i.e. information useful over all trials). Performance was similarly affected following either cholinotoxin or anticholinergic treatment, regardless of the response strategy utilized. In addition, rates of behavioral recovery following cholinotoxin treatment were similar between response groups. It was concluded that both cholinotoxin and anticholinergic treatment primarily resulted in impaired reference memory processes. ^

Biblioclast��a y bibliotecolog��a : Recuerdos que resisten en la ciudad de La Plata

La biblioclast��a fue definida como la compulsi��n humana por destruir libros. Desde tiempos inmemoriales el hombre ha querido imponer sus ideas a trav��s de la destrucci��n de aquellas que se contrapon��an a las propias y los libros han sido objeto de esa "pulsi��n bibliocl��stica" durante toda la historia de la humanidad. La ��ltima dictadura militar que sufri�� nuestro pa��s dej�� importantes secuelas en la sociedad. Mediante la censura e intervenci��n en diferentes ��mbitos (educaci��n, cine, teatro, literatura, entre otros) se construyeron un discurso, un lenguaje y unas pr��cticas que hoy se reconocen como propias de ese tiempo hist��rico. Igual que pas�� con la desaparici��n de las personas y sus cuerpos, la represi��n en el ��mbito de la cultura fue parte de un plan sistem��tico, pensado, calculado y llevado a cabo por dependencias del Estado argentino destinadas a tal fin y por funcionarios (militares y civiles) que fueron parte de ese plan. Se considera de especial importancia que los bibliotecarios, como parte de aqu��llos profesionales que contribuyen d��a a d��a a la preservaci��n de la memoria, abordemos este tipo de problem��ticas y reflexionemos en torno de la mismas. Este trabajo se enmarca en las investigaciones sobre el pasado reciente, teniendo como eje la Declaraci��n Universal de los Derechos Humanos y su postura frente a la libertad de expresi��n. Intenta reconstruir los mecanismos censorios y c��mo se plasmaron en las vivencias de diferentes actores relacionados con el ��mbito del libro y del movimiento cultural y pol��tico platense, con el objetivo de contribuir a la memoria social de nuestra ciudad.

Haiti : The 'invisibility' of a territory to build projects that strengthen their autonomy

Haiti, conocida en la ��poca colonial como 'la Perla de las Antillas', su econom��a se organiz�� entorno a la producci��n de az��car que prove��an a trav��s de Francia al resto de Europa. De este modo 70de la producci��n de az��car era consumido en Europa y m��s del 60del caf��. Con una l��gica que persegu��a obtener los m��ximos rindes, buscaron mano de obra esclava en el ��frica Subsahariana, poblaci��n que directamente reemplaz�� a la originaria. As�� comienza a plantearse el desarrollo de un tipo de econom��a en Haiti, que traer��a graves consecuencias ambientales hasta la actualidad. Hoy es el pa��s m��s pobre de Am��rica, con una esperanza de vida de alrededor de 60 a��os, y la tasa de analfabetismo del 52. Ubicado en un ��rea tropical, es frecuente que sufra el impacto de las tormentas tropicales y ciclones que, como consecuencia de una tala desmedida de laforestaci��n originaria, las inundaciones acent��an los problemas, a lo que se suman los problemas sanitarios inherentes a un nivel de vida con tantas carencias; y a la preponderancia de minifundios en el ��rea rural, llevan a conformar un escenario de enorme vulnerabilidad. En el a��o 2010, una triste noticia pondr��a a Ha��ti en el centro de la escena mundial: el terremoto de marzo de ese a��o que afectara el ��rea de Puerto Pr��ncipe dejando alrededor de 300.000 muertos y m��s de un mill��n de damnificados. En la actualidad la presencia debarrios enteros viviendo en carpas en espacios p��blicos, son una expresi��n de la vigencia de dicho evento. Sin embargo, desde mediados de la d��cada pasada tienen lugar proyectos que intentan territorializar una experiencia argentina de reconocido impacto en procura de atender las necesidades de la poblaci��n con mayor vulnerabilidad que habita en los espacios rurales. Se trata del Programa Pro Huerta, que desde hace m��s de veinte a��os se desarrolla en Argentina y se propuso en el ��mbito de este pa��s desde la perspectiva de la cooperaci��n internacional. De este modo, en distintos departamentos de Haiti con el trabajo en conjunto de diversos pa��ses ponen en marcha un proyecto social de seguridad alimentaria. La finalidad es el an��lisis de la territorializaci��n de la experiencia Pro Huerta Haiti a partir del enfoque de cooperaci��n internacional del cual Argentina participa junto con Canad�� y Haiti. Entre los resultados y aportes de esta investigaci��n, se pudo constatar que en Ha��t�� se fortalecen las redes sociales, la familia, el trabajo solidario, la salud y en conjunto contribuyen a fortalecer la soberan��a alimentaria, en un pa��s con grandes carencias y gran vulnerabilidad. Asimismo, es interesante resaltar que el modelo de Cooperaci��n Sur-Sur que la Argentina desarrolla, desde una visi��n horizontal donde nuestro pa��s camina junto a Hait�� y Canad�� en el aprendizaje cotidiano del crecimiento conjunto, donde cada pa��s tiene mucho por seguir aprendiendo

"Palo a Pique": Anales de la Sociedad Rural

La presente comunicaci��n analiza la posici��n de la Sociedad Rural de Gualeguaych�� ante diversas pol��ticas p��blicas destinadas al agro entre 1979 y 1982 a trav��s de la publicaci��n vocera de la entidad, la revista Palo a Pique , nacida en 1979 con el subt��tulo de Anales de la Sociedad Rural. La revista que trata diversas cuestiones vinculadas al sector agr��cola, tiene la funci��n de informar y educar al productor, al tiempo que pretende reflejar sus demandas frente al Estado nacional y provincial, cuando ��stos aplican medidas de car��cter tributario que atentan -seg��n la publicaci��n- contra el normal desarrollo de las actividades rurales.

��El museo como forma de "conocer la Historia"? El p��blico interpreta la inmigraci��n

El trabajo analiza c��mo la exposici��n presentada en el Museo Nacional de la Inmigraci��n fue aprehendida e interpretada por su p��blico visitante. Dependiente de la Direcci��n Nacional de Migraciones, el Museo funcion�� entre los a��os 2001 y 2009 en el edificio del antiguo Hotel de Inmigrantes (en Retiro). Para este estudio utilizamos m��s de 700 mensajes registrados en el Libro de Visitas del Museo, que fueron clasificados en nueve categor��as, de acuerdo a los aspectos comunes que expresaban. A lo largo del an��lisis, el concepto de memoria se volvi�� fundamental para comprender los sentimientos y deseos expresados por el p��blico que visit�� la instituci��n. Dentro de los temas que aparecieron en los mensajes, pudimos verificar la importancia que le atribu��an los visitantes al Estado argentino por la construcci��n del Hotel, la recepci��n de los inmigrantes y, actualmente, por la preservaci��n de su memoria y patrimonio; tambi��n se evidenci�� un agradecimiento a los inmigrantes, cuya "fuerza" y "esperanza" contribuyeron al desarrollo del pa��s

Exilio y autotraducci��n en la narrativa testimonial concentracionaria argentina : El caso de The Little School. Tales of Disappearance and Survival in Argentina, de Alicia Partnoy (1986)

Algunos escritores exiliados a partir de la ��ltima dictadura militar argentina (1976-1983) tradujeron ellos mismos sus textos para publicarlos en el pa��s de exilio. Un ejemplo es el de Alicia Partnoy, autora de The Little School. Tales of Disappearance & Survival in Argentina, quien habiendo escrito un testimonio en espa��ol sobre su paso por el campo de concentraci��n La Escuelita, ubicado en Bah��a Blanca, se dedic�� a traducirlo al ingl��s para su publicaci��n en Estados Unidos en 1986. Sus numerosas ediciones, primero en el extranjero y m��s tarde en Argentina, lo ubican entre una de las obras m��s importantes de la narrativa testimonial concentracionaria argentina. Una forma de abordarlo reside en el an��lisis sobre el proceso y el resultado de la autotraducci��n, lo cual permite aportar elementos de reflexi��n acerca de la necesidad de los supervivientes exiliados de dar a conocer su experiencia en el exilio, algo que sobrepasa, incluso, las barreras ling����sticas

Incidencia de la mecanizaci��n agraria en la estructura comercial local entrerriana. La Ferreter��a "Irigoyen" de Gualeguaych��, 1953-1960

Este trabajo de investigaci��n estudia la incidencia en la estructura comercial que produce la mecanizaci��n del campo, impulsada desde el gobierno nacional en la mitad del siglo XX. Las demandas de los productores de la zona de Gualeguaych��, Entre R��os, provocan el esfuerzo del comercio local por satisfacerlas. Muestra clara de este proceso es el desenvolvimiento desarrollado por la firma "Ferreter��a Irigoyen", debiendo adaptarse a los nuevos tiempos. El an��lisis de la documentaci��n del comercio, de los diarios locales y del testimonio oral, nos permite reflejar el impacto que caus�� la transformaci��n agropecuaria en la estructura comercial de la firma.

"Palo a Pique": Anales de la Sociedad Rural

La presente comunicaci��n analiza la posici��n de la Sociedad Rural de Gualeguaych�� ante diversas pol��ticas p��blicas destinadas al agro entre 1979 y 1982 a trav��s de la publicaci��n vocera de la entidad, la revista Palo a Pique , nacida en 1979 con el subt��tulo de Anales de la Sociedad Rural. La revista que trata diversas cuestiones vinculadas al sector agr��cola, tiene la funci��n de informar y educar al productor, al tiempo que pretende reflejar sus demandas frente al Estado nacional y provincial, cuando ��stos aplican medidas de car��cter tributario que atentan -seg��n la publicaci��n- contra el normal desarrollo de las actividades rurales.

��El museo como forma de "conocer la Historia"? El p��blico interpreta la inmigraci��n

El trabajo analiza c��mo la exposici��n presentada en el Museo Nacional de la Inmigraci��n fue aprehendida e interpretada por su p��blico visitante. Dependiente de la Direcci��n Nacional de Migraciones, el Museo funcion�� entre los a��os 2001 y 2009 en el edificio del antiguo Hotel de Inmigrantes (en Retiro). Para este estudio utilizamos m��s de 700 mensajes registrados en el Libro de Visitas del Museo, que fueron clasificados en nueve categor��as, de acuerdo a los aspectos comunes que expresaban. A lo largo del an��lisis, el concepto de memoria se volvi�� fundamental para comprender los sentimientos y deseos expresados por el p��blico que visit�� la instituci��n. Dentro de los temas que aparecieron en los mensajes, pudimos verificar la importancia que le atribu��an los visitantes al Estado argentino por la construcci��n del Hotel, la recepci��n de los inmigrantes y, actualmente, por la preservaci��n de su memoria y patrimonio; tambi��n se evidenci�� un agradecimiento a los inmigrantes, cuya "fuerza" y "esperanza" contribuyeron al desarrollo del pa��s