Implementation of an Anthropomorphic Phantom for the Evaluation of Proton Therapy Treatment Procedures

With an increasing number of institutions offering proton therapy, the number of multi-institutional clinical trials involving proton therapy will also increase in the coming years. The Radiological Physics Center monitors sites involved in clinical trials through the use of site visits and remote auditing with thermoluminescent dosimeters (TLD) and mailable anthropomorphic phantoms. Currently, there are no heterogeneous phantoms that have been commissioned to evaluate proton therapy. It was hypothesized that an anthropomorphic pelvis phantom can be designed to audit treatment procedures (patient simulation, treatment planning and treatment delivery) at proton facilities to confirm agreement between the measured dose and calculated dose within 5%/3mm with a reproducibility of 3%. A pelvis phantom originally designed for use with photon treatments was retrofitted for use in proton therapy. The relative stopping power (SP) of each phantom material was measured. Hounsfield Units (HU) for each phantom material were measured with a CT scanner and compared to the relative stopping power calibration curve. The tissue equivalency for each material was calculated. Two proton treatment plans were created; one which did not correct for material SP differences (Plan 1) and one plan which did correct for SP differences (Plan 2). Film and TLD were loaded into the phantom and the phantom was irradiated 3 times per plan. The measured values were compared to the HU-SP calibration curve and it was found that the stopping powers for the materials could be underestimated by 5-10%. Plan 1 passed the criteria for the TLD and film margins with reproducibility under 3% between the 3 trials. Plan 2 failed because the right-left film dose profile average displacement was -9.0 mm on the left side and 6.0 mm on the right side. Plan 2 was intended to improve the agreements and instead introduced large displacements along the path of the beam. Plan 2 more closely represented the actual phantom composition with corrected stopping powers and should have shown an agreement between the measured and calculated dose within 5%/3mm. The hypothesis was rejected and the pelvis phantom was found to be not suitable to evaluate proton therapy treatment procedures.

Ethnic Minority Children’s Active Commuting to School and Association with Physical Activity and Pedestrian Safety Behaviors

Background: Children's active commuting to school, i.e. walking or cycling to school, was associated with greater moderate-to-vigorous physical activity, although studies among ethnic minorities are sparse. Objectives: Among a low-income, ethnic minority sample of fourth grade students from eight public schools, we examined (1) correlates of active commuting to school and (2) the relationship between active commuting to school and moderate-to-vigorous physical activity. Methods: We conducted a cross-sectional analysis of baseline measurements from a sample of participants (n=149) aged 9-12 years from a walk to school intervention study in Houston, Texas. The primary outcome was the weekly rate of active commuting to school. Daily moderate-to-vigorous physical activity, measured by accelerometers, was a secondary outcome. Child self-efficacy (alpha=0.75), parent self-efficacy (alpha=0.88), and parent outcome expectations (alpha=0.78) were independent variables. Participant characteristics (age, gender, race/ethnicity, distance from home to school, acculturation, and BMI percentile) were independent sociodemographic variables. We used mixed-model regression analyses to account for clustering by school and a stepwise procedure with backward elimination of non-significant interactions and covariates to identify significant moderators and predictors. School-level observations of student pedestrians were assessed and compared using chi-square tests of independence. Results: Among our sample, which was 61.7% Latino, the overall rate of active commuting to school was 43%. In the mixed model for active commuting to school, parent self-efficacy (std. beta = 0.18, p=0.018) and age (std. beta = 0.18, p=0.018) were positively related. Latino students had lower rates of active commuting to school than non-Latinos ( 16.5%, p=0.040). Distance from home to school was inversely related to active commuting to school (std. beta = 0.29, p<0.001). In the mixed model for moderate-to-vigorous physical activity, active commuting to school was positively associated (std. beta = 0.31, p <0.001). Among the Latino subsample, child acculturation was negatively associated with active commuting to school (std. beta = -0.23, p=0.01). With regard to school-level pedestrian safety observations, 37% of students stopped at the curb and 2.6% looked left-right-left before crossing the street. Conclusion: Although still below national goals, the rate of active commuting was relatively high, while the rate of some pedestrian safety behaviors was low among this low-income, ethnic minority population. Programs and policies to encourage safe active commuting to school are warranted and should consider the influence of parents, acculturation, and ethnicity.

Time for actions in lucid dreams: effects of task modality, length, and complexity

The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for these condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.

Virtual tissue alignment and cutting plane definition--a new method to obtain optimal longitudinal histological sections.

Histomorphometric evaluation of the buccal aspects of periodontal tissues in rodents requires reproducible alignment of maxillae and highly precise sections containing central sections of buccal roots; this is a cumbersome and technically sensitive process due to the small specimen size. The aim of the present report is to describe and analyze a method to transfer virtual sections of micro-computer tomographic (CT)-generated image stacks to the microtome for undecalcified histological processing and to describe the anatomy of the periodontium in rat molars. A total of 84 undecalcified sections of all buccal roots of seven untreated rats was analyzed. The accuracy of section coordinate transfer from virtual micro-CT slice to the histological slice, right-left side differences and the measurement error for linear and angular measurements on micro-CT and on histological micrographs were calculated using the Bland-Altman method, interclass correlation coefficient and the method of moments estimator. Also, manual alignment of the micro-CT-scanned rat maxilla was compared with multiplanar computer-reconstructed alignment. The supra alveolar rat anatomy is rather similar to human anatomy, whereas the alveolar bone is of compact type and the keratinized gingival epithelium bends apical to join the junctional epithelium. The high methodological standardization presented herein ensures retrieval of histological slices with excellent display of anatomical microstructures, in a reproducible manner, minimizes random errors, and thereby may contribute to the reduction of number of animals needed.

Estudio Multimodal de la Funcionalidad Cortical en ratones Transgénicos con Síndrome X Frágil y la modulación del dolor

El dolor es un síntoma frecuente en la práctica médica. En España, un estudio realizado en el año 2000 demostró que cada médico atiende un promedio de 181 pacientes con dolor por mes, la mayoría de ellos con dolor crónico moderado1. Del 7%-8% de la población europea está afectada y hasta el 5% puede ser grave2-3, se estima, que afecta a más de dos millones de españoles4. En la consulta de Atención Primaria, los pacientes con dolor neuropático tienen tasas de depresión mucho mayores 5-6-7. El dolor neuropático8 es el dolor causado por daño o enfermedad que afecta al sistema somato-sensorial, es un problema de salud pública con un alto coste laboral, debido a que existe cierto desconocimiento de sus singularidades, tanto de su diagnóstico como de su tratamiento, que al fallar, el dolor se perpetúa y se hace más rebelde a la hora de tratarlo, en la mayoría de las ocasiones pasa a ser crónico. Los mecanismos fisiopatológicos son evolutivos, se trata de un proceso progresivo e integrado que avanza si no recibe tratamiento, ocasionando graves repercusiones en la calidad de vida de los pacientes afectados9. De acuerdo a Prusiner (premio nobel de medicina 1997), en todas las enfermedades neurodegenerativas hay algún tipo de proceso anormal de la función neuronal. Las enfermedades neurodegenerativas son la consecuencia de anormalidades en el proceso de ciertas proteínas que intervienen en el ciclo celular, por lo tanto da lugar al cúmulo de las mismas en las neuronas o en sus proximidades, disminuyendo o anulando sus funciones, como la enfermedad de Alzheimer y el mismo SXF. La proteína FMRP (Fragile Mental Retardation Protein), esencial para el desarrollo cognitivo normal, ha sido relacionada con la vía piramidal del dolor10-11-12. El Síndrome de X Frágil13-14 (SXF), se debe a la mutación del Gen (FMR-1). Como consecuencia de la mutación, el gen se inactiva y no puede realizar la función de sintetizar la proteína FMRP. Por su incidencia se le considera la primera causa de Deficiencia Mental Hereditaria sólo superada por el Síndrome de Down. La electroencefalografía (EEG) es el registro de la actividad bioeléctrica cerebral que ha traído el desarrollo diario de los estudios clínicos y experimentales para el descubrimiento, diagnóstico y tratamiento de un gran número de anormalidades neurológicas y fisiológicas del cerebro y el resto del sistema nervioso central (SNC) incluyendo el dolor. El objetivo de la presente investigación es por medio de un estudio multimodal, desarrollar nuevas formas de presentación diagnóstica mediante técnicas avanzadas de procesado de señal y de imagen, determinando así los vínculos entre las evaluaciones cognitivas y su correlación anatómica con la modulación al dolor presente en patologías relacionadas con proteína FMRP. Utilizando técnicas biomédicas (funcionalestructural) para su caracterización. Para llevar a cabo esta tarea hemos utilizado el modelo animal de ratón. Nuestros resultados en este estudio multimodal demuestran que hay alteraciones en las vías de dolor en el modelo animal FMR1-KO, en concreto en la modulación encefálica (dolor neuropático), los datos se basan en los resultados del estudio estructural (imagen histología), funcional (EEG) y en pruebas de comportamiento (Laberinto de Barnes). En la Histología se muestra una clara asimetría estructural en el modelo FMR1 KO con respecto al control WT, donde el hemisferio Izquierdo tiene mayor densidad de masa neuronal en KO hembras 56.7%-60.8%, machos 58.3%-61%, en WT hembras 62.7%-62.4%, machos 55%-56.2%, hemisferio derecho-izquierdo respectivamente, esto refleja una correlación entre hemisferios muy baja en los sujetos KO (~50%) con respecto a los control WT (~90%). Se encontró correlación significativa entre las pruebas de memoria a largo plazo con respecto a la asimetría hemisférica (r = -0.48, corregido <0,05). En el estudio de comportamiento también hay diferencias, los sujetos WT tuvieron 22% un de rendimiento en la memoria a largo plazo, mientras que en los machos hay deterioro de memoria de un 28% que se corresponden con la patología en humanos. En los resultados de EEG estudiados en el hemisferio izquierdo, en el área de la corteza insular, encuentran que la latencia de la respuesta al potencial evocado es menor (22vs32 15vs96seg), la intensidad de la señal es mayor para los sujetos experimentales FMR1 KO frente a los sujetos control, esto es muy significativo dados los resultados en la histología (140vs129 145vs142 mv). Este estudio multimodal corrobora que las manifestaciones clínicas del SXF son variables dependientes de la edad y el sexo. Hemos podido corroborar en el modelo animal que en la etapa de adulto, los varones con SXF comienzan a desarrollar problemas en el desempeño de tareas que requieren la puesta en marcha de la función ejecutiva central de la memoria de trabajo (almacenamiento temporal). En el análisis del comportamiento es difícil llegar a una conclusión objetiva, se necesitan más estudios en diferentes etapas de la vida corroborados con resultados histológicos. Los avances logrados en los últimos años en su estudio han sido muy positivos, de tal modo que se están abriendo nuevas vías de investigación en un conjunto de procesos que representan un gran desafío a problemas médicos, asistenciales, sociales y económicos a los que se enfrentan los principales países desarrollados, con un aumento masivo de las expectativas de vida y de calidad. Las herramientas utilizadas en el campo de las neurociencias nos ofrecen grandes posibilidades para el desarrollo de estrategias que permitan ser utilizadas en el área de la educación, investigación y desarrollo. La genética determina la estructura del cerebro y nuestra investigación comprueba que la ausencia de FMRP también podría estar implicada en la modulación del dolor como parte de su expresión patológica siendo el modelo animal un punto importante en la investigación científica fundamental para entender el desarrollo de anormalidades en el cerebro. ABSTRACT Pain is a common symptom in medical practice. In Spain, a study conducted in 2000 each medical professional treats an average of 181 patients with pain per month, most of them with chronic moderate pain. 7% -8% of the European population is affected and up to 5% can be serious, it is estimated to affect more than two million people in Spain. In Primary Care, patients with neuropathic pain have much higher rates of depression. Neuropathic pain is caused by damage or disease affecting the somatosensory system, is a public health problem with high labor costs, there are relatively unfamiliar with the peculiarities in diagnosis and treatment, failing that, the pain is perpetuated and becomes rebellious to treat, in most cases becomes chronic. The pathophysiological mechanisms are evolutionary, its a progressive, if untreated, causing severe impact on the quality of life of affected patients. According to Prusiner (Nobel Prize for Medicine 1997), all neurodegenerative diseases there is some abnormal process of neuronal function. Neurodegenerative diseases are the result of abnormalities in the process of certain proteins involved in the cell cycle, reducing or canceling its features such as Alzheimer's disease and FXS. FMRP (Fragile Mental Retardation Protein), is essential for normal cognitive development, and has been linked to the pyramidal tract pain. Fragile X Syndrome (FXS), is due to mutation of the gene (FMR-1). As a consequence of the mutation, the gene is inactivated and can not perform the function of FMRP synthesize. For its incidence is considered the leading cause of Mental Deficiency Hereditary second only to Down Syndrome. Electroencephalography (EEG) is the recording of bioelectrical brain activity, is a advancement of clinical and experimental studies for the detection, diagnosis and treatment of many neurological and physiological abnormalities of the brain and the central nervous system, including pain. The objective of this research is a multimodal study, is the development of new forms of presentation using advanced diagnostic techniques of signal processing and image, to determine the links between cognitive evaluations and anatomic correlation with pain modulation to this protein FMRP-related pathologies. To accomplish this task have used the mouse model. Our results in this study show alterations in multimodal pain pathways in FMR1-KO in brain modulation (neuropathic pain), the data are based on the results of the structural study (histology image), functional (EEG) testing and behavior (Barnes maze). Histology In structural asymmetry shown in FMR1 KO model versus WT control, the left hemisphere is greater density of neuronal mass (KO females 56.7% -60.8%, 58.3% -61% males, females 62.7% -62.4 WT %, males 55% -56.2%), respectively right-left hemisphere, this reflects a very low correlation between hemispheres in KO (~ 50%) subjects compared to WT (~ 90%) control. Significant correlation was found between tests of long-term memory with respect to hemispheric asymmetry (r = -0.48, corrected <0.05). In the memory test there are differences too, the WT subjects had 22% yield in long-term memory, in males there memory impairment 28% corresponding to the condition in humans. The results of EEG studied in the left hemisphere, in insular cortex area, we found that the latency of the response evoked potential is lower (22vs32 15vs96seg), the signal strength is higher for the experimental subjects versus FMR1 KO control subjects, this is very significant given the results on histology (140vs129 145vs142 mv). This multimodal study confirms that the clinical manifestations of FXS are dependent variables of age and sex. We have been able to corroborate in the animal model in the adult stage, males with FXS begin developing problems in the performance of tasks that require the implementation of the central executive function of working memory (temporary storage). In behavior analysis is difficult to reach an objective conclusion, more studies are needed in different life stages corroborated with histologic findings. Advances in recent years were very positive, being opened new lines of research that represent a great challenge to physicians, health care, social and economic problems facing the major developed countries, with a massive increase in life expectancy and quality. The tools used in the field of neuroscience offer us great opportunities for the development of strategies to be used in the area of education, research and development. Genetics determines the structure of the brain and our research found that the absence of FMRP might also be involved in the modulation of pain as part of their pathological expression being an important animal model in basic scientific research to understand the development of abnormalities in brain.

Análisis de imágenes del rostro humano

El objetivo general de este trabajo es el correcto funcionamiento de un sistema de reconocimiento facial compuesto de varios módulos, implementados en distintos lenguajes. Uno de dichos módulos está escrito en Python y se encargarí de determinar el género del rostro o rostros que aparecen en una imagen o en un fotograma de una secuencia de vídeo. El otro módulo, escrito en C++, llevará a cabo el reconocimiento de cada una de las partes de la cara (ojos, nariz, boca) y la orientación hacia la que está posicionada (derecha, izquierda). La primera parte de esta memoria corresponde a la reimplementación de todas las partes de un analizador facial, que constituyen el primer módulo antes mencionado. Estas partes son un analizador, compuesto a su vez por un reconocedor (Tracker) y un procesador (Processor), y una clase visor para poder visualizar los resultados. Por un lado, el reconocedor o "Tracker.es el encargado de encontrar la cara y sus partes, que serán pasadas al procesador o Processor, que analizará la cara obtenida por el reconocedor y determinará su género. Este módulo estaba dise~nado completamente en C y OpenCV 1.0, y ha sido reescrito en Python y OpenCV 2.4. Y en la segunda parte, se explica cómo realizar la comunicación entre el primer módulo escrito en Python y el segundo escrito en C++. Además, se analizarán diferentes herramientas para poder ejecutar código C++ desde programas Python. Dichas herramientas son PyBindGen, Cython y Boost. Dependiendo de las necesidades del programador se contará cuál de ellas es más conveniente utilizar en cada caso. Por último, en el apartado de resultados se puede observar el funcionamiento del sistema con la integración de los dos módulos, y cómo se muestran por pantalla los puntos de interés, el género y la orientación del rostro utilizando imágenes tomadas con una cámara web.---ABSTRACT---The main objective of this document is the proper functioning of a facial recognition system composed of two modules, implemented in diferent languages. One of these modules is written in Python, and his purpose is determining the gender of the face or faces in an image or a frame of a video sequence. The other module is written in C ++ and it will perform the recognition of each of the parts of the face (eyes, nose , mouth), and the head pose (right, left).The first part of this document corresponds to the reimplementacion of all components of a facial analyzer , which constitute the first module that I mentioned before. These parts are an analyzer , composed by a tracke) and a processor, and a viewer to display the results. The tracker function is to find and its parts, which will be passed to the processor, which will analyze the face obtained by the tracker. The processor will determine the face's gender. This module was completely written in C and OpenCV 1.0, and it has been rewritten in Python and OpenCV 2.4. And in the second part, it explains how to comunicate two modules, one of them written in Python and the other one written in C++. Furthermore, it talks about some tools to execute C++ code from Python scripts. The tools are PyBindGen, Cython and Boost. It will tell which one of those tools is better to use depend on the situation. Finally, in the results section it is possible to see how the system works with the integration of the two modules, and how the points of interest, the gender an the head pose are displayed on the screen using images taken from a webcam.

Entre: de repente, sin fin, lo innombrable

Etiquetamos para reducir nuestra incertidumbre; clasificamos en base a términos opuestos para poder entender. El universo y el espacio construido en particular, se explican desde una arquitectónica dual: dentro – fuera, arriba – abajo, derecha – izquierda, día – noche, hombre – mujer. Lo que nos diferencia como grupo, raza o género, distinguiendo los modos de vivir, las ideologías y las teorías, es la relación que establecemos entre los términos opuestos: entre lo individual y lo colectivo, lo privado y lo público, la imaginación y la realidad, la identidad y la otredad, el orden y el caos, el deseo y la saciedad. El afán clasificatorio dicotómico de la realidad que la modernidad lleva a su extremo, hiere la vida: la mutua exclusión de los opuestos elimina la distancia, el espacio-tiempo entre ambos, que es donde la vida se sitúa. La concepción dual que rige nuestro conocimiento contamina también la relación entre los arquitectos y la sociedad, siendo la causa del ambiente tóxico que envuelve al habitante que ya no se identifica con los lugares que habita. Puede que sea oportuno pasar del pensamiento binario a una lógica de lo intersticial que abandone la dualidad para instalarse en el Entre; los arquitectos serían mediadores entre el poder y la vida, sintiendo el Entre como el transcurso de la vida y la potencia de interacción: los lugares ambiguos e intermedios, es donde sucede el encuentro entre los términos, entre arquitectos y habitantes, entre la imaginación y la realidad, entre tú y yo. ABSTRACT We label to reduce our uncertainty; we classify based on opposites to understand. The universe and all constructed space in particular, are explained from a dual architecture: inside - out, up - down, right - left, day - night, male - female, black - white. What differentiate us as a group, race, gender, distinguishing the lifestyles, ideologies and theories, is how we draw the relation between the opposites: between the individual and the collective, private and public, imagination and reality , identity and otherness, order and disorder, desire and satiety. The dichotomous classification of reality that modernity carried to its extreme, hurts life: the mutual exclusion of opposites eliminates the distance, the space-time between the two, which is where life is located. The dual conception that governs our knowledge has also contaminated the relationship between architect and society, being the cause of the toxic environment that surrounds the inhabitant who no longer identify himself with the places he inhabit. It may be appropriate pass from binary thinking to a logic of the interstitial which abandon duality to settle in Between; architect then will be the mediator between authorities and life, sensing the Between as a flowing of life a potency of interaction rather than a separation between the extremes; ambiguous, in –between, places are where the encounter between opposites happens, between the architect and the inhabitant, between imagination and reality, between you and me.

Neural fate of seen and unseen faces in visuospatial neglect: A combined event-related functional MRI and event-related potential study

To compare neural activity produced by visual events that escape or reach conscious awareness, we used event-related MRI and evoked potentials in a patient who had neglect and extinction after focal right parietal damage, but intact visual fields. This neurological disorder entails a loss of awareness for stimuli in the field contralateral to a brain lesion when stimuli are simultaneously presented on the ipsilateral side, even though early visual areas may be intact, and single contralateral stimuli may still be perceived. Functional MRI and event-related potential study were performed during a task where faces or shapes appeared in the right, left, or both fields. Unilateral stimuli produced normal responses in V1 and extrastriate areas. In bilateral events, left faces that were not perceived still activated right V1 and inferior temporal cortex and evoked nonsignificantly reduced N1 potentials, with preserved face-specific negative potentials at 170 ms. When left faces were perceived, the same stimuli produced greater activity in a distributed network of areas including right V1 and cuneus, bilateral fusiform gyri, and left parietal cortex. Also, effective connectivity between visual, parietal, and frontal areas increased during perception of faces. These results suggest that activity can occur in V1 and ventral temporal cortex without awareness, whereas coupling with dorsal parietal and frontal areas may be critical for such activity to afford conscious perception.

Functional neuroimaging studies of encoding, priming, and explicit memory retrieval

Human functional neuroimaging techniques provide a powerful means of linking neural level descriptions of brain function and cognition. The exploration of the functional anatomy underlying human memory comprises a prime example. Three highly reliable findings linking memory-related cognitive processes to brain activity are discussed. First, priming is accompanied by reductions in the amount of neural activation relative to naive or unprimed task performance. These reductions can be shown to be both anatomically and functionally specific and are found for both perceptual and conceptual task components. Second, verbal encoding, allowing subsequent conscious retrieval, is associated with activation of higher order brain regions including areas within the left inferior and dorsal prefrontal cortex. These areas also are activated by working memory and effortful word generation tasks, suggesting that these tasks, often discussed as separable, might rely on interdependent processes. Finally, explicit (intentional) retrieval shares much of the same functional anatomy as the encoding and word generation tasks but is associated with the recruitment of additional brain areas, including the anterior prefrontal cortex (right > left). These findings illustrate how neuroimaging techniques can be used to study memory processes and can both complement and extend data derived through other means. More recently developed methods, such as event-related functional MRI, will continue this progress and may provide additional new directions for research.

Optics and Optoelectronics of Two-dimensional Semiconducting Monolayers and Heterostructures

Thesis (Ph.D.)--University of Washington, 2016-06

Shape of the posterior vitreous chamber in human emmetropia and myopia

PURPOSE - To compare posterior vitreous chamber shape in myopia to that in emmetropia. METHODS - Both eyes of 55 adult subjects were studied, 27 with emmetropia (MSE =-0.55; <+0.75D; mean +0.09 ±0.36D) and 28 with myopia (MSE -5.87 ±2.31D). Cycloplegic refraction was measured with a Shin Nippon autorefractor and anterior chamber depth and axial length with a Zeiss IOLMaster. Posterior vitreous chamber shapes were determined from T2-weighted MRI (3-Tesla) using procedures previously reported by our laboratory. 3-D surface model coordinates were assigned to nasal, temporal, superior and inferior quadrants and plotted in 2-D to illustrate the composite shape of respective quadrants posterior to the second nodal point. Spherical analogues of chamber shape were constructed to compare relative sphericity between refractive groups and quadrants. RESULTS - Differences in shape occurred in the region posterior to points of maximum globe width and were thus in general accord with an equatorial model of myopic expansion. Shape in emmetropia is categorised distinctly as that of an oblate ellipse and in myopia as an oblate ellipse of significantly less degree such that it approximates to a sphere. There was concordance between shape and retinotopic projection of respective quadrants into right, left, superior and inferior visual fields. CONCLUSIONS - The transition in shape from oblate ellipse to sphere with axial elongation supports the hypothesis that myopia may be a consequence of equatorial restriction associated with biomechanical anomalies of the ciliary apparatus. The synchronisation of quadrant shapes with retinotopic projection suggests that binocular growth is coordinated by processes that operate beyond the optic chiasm.

The Big Crunch : A Mapping of the Swedish Party System from 1991 to 2010

Previous research claims that there has been a narrowing of distance between the Swedish political parties. Typically, such research into political distance has primarily focused on studying voters rather than the political parties themselves. In this article, the author conducts a longitudinal analysis of Comparative Manifesto Project data to determine if, and to what extent, the political parties have converged ideologically on a Left-Right continuum in the period 1991-2010. After first unraveling the concept of political distance, the author moves on to explain why the ideological dispersion of political parties is an important and consequential characteristic within party systems. Furthermore, the author argues that the Left-Right ideological scale continues to be a highly useful model with which to conceptualize and study this characteristic. The author then discusses the methodological approach and explains why quantitative manifesto data, often overlooked in favor of voter interview data, is deemed a valid and reliable material for measuring the ideological positions of political parties. The findings are that there indeed have been over all tendencies of ideological convergence between the blocs and that, in terms of how political parties are dispersed on a Left- Right ideological continuum, by 2010, the Swedish party system (the Sweden Democrats excluded) had become much less polarized than it had been in 1991.

Odontometric analysis of molars for sex determination

Aim: To investigate the existence of sexual dimorphism between the first and second permanent molars. Methods: A cross-sectional, observational, blind study using comparative and statistical descriptive procedures. The sample included 50 pairs of plaster casts from undergraduate dental students (25 men/25 women) from the Federal University of Paraíba, João Pessoa/PB, Brazil, aged 20-26 years. Odontometric measurements of first and second maxillary/mandibular, right/left permanent molars were performed. Mesiodistal (MD) and buccolingual/palatal (BL/BP) widths and the distance between the lingual cusps of corresponding molars in opposite quadrants, were measured. The data were analyzed by Student’s t test and ANOVA with Bonferroni (p≤0.05). Results: The crowns of all first molars were statistically larger in men than in women (p<0.05). Maxillary and mandibular left second molars (#27 and #37) did not differ in their MD widths (p=0.66, p=0.75), whereas mandibular left and right second molars (#37 and #47) showed statistically different BL widths (p=0.007 and p=0.008). As to the distance between the lingual cusps, only the first left-to-right mandibular molars (#36-46) showed no sex dimorphism (p=0.107). Conclusions: Molars are larger in males than in females. Individually, first molars demonstrated higher evidence of sex distinction than second molars.

À contre-courant du progrès : une esquisse de la pensée de Christopher Lasch

En retraçant le parcours intellectuel de l’historien, moraliste et critique américain Christopher Lasch, ce mémoire vise à mettre en exergue la pertinence et les subtilités de sa pensée politique. Sur la base d’une analyse de ses principaux textes, nous démontrerons, qu’au-delà du pessimisme et du catastrophisme qui lui sont généralement attribués, Lasch porte un regard fécond sur la singularité de l’époque contemporaine. Nous soutiendrons que ses critiques acerbes sur la société et l’individu sont faites, avant tout, dans le but de remédier aux carences morales et sociétales qui auraient engendré un certain idéal libéral progressiste. Selon Lasch, le déploiement continu et illimité de cet idéal est en dissonance avec le caractère essentiellement contingent et conflictuel de la condition humaine. Parallèlement, nous présenterons les incidences psychiques qui se traduisent par une « culture du narcissisme » suscitée notamment par diverses composantes de la société contemporaine. À travers une relecture de la condition humaine, Lasch préconise un correctif idéologique qui est axé sur les notions de limites et d’espoir et qui se trouve au sein de la tradition agraire populiste américaine du 19e siècle. Nous démontrerons ainsi comment ce retour en arrière est entamé dans le but de susciter un renouveau politique et identitaire au sein de la société. L’étude se conclura par une discussion sur la plausibilité de l’idéal populiste, tel que l’entend Lasch, à l’ère du 21e siècle.

À contre-courant du progrès : une esquisse de la pensée de Christopher Lasch

En retraçant le parcours intellectuel de l’historien, moraliste et critique américain Christopher Lasch, ce mémoire vise à mettre en exergue la pertinence et les subtilités de sa pensée politique. Sur la base d’une analyse de ses principaux textes, nous démontrerons, qu’au-delà du pessimisme et du catastrophisme qui lui sont généralement attribués, Lasch porte un regard fécond sur la singularité de l’époque contemporaine. Nous soutiendrons que ses critiques acerbes sur la société et l’individu sont faites, avant tout, dans le but de remédier aux carences morales et sociétales qui auraient engendré un certain idéal libéral progressiste. Selon Lasch, le déploiement continu et illimité de cet idéal est en dissonance avec le caractère essentiellement contingent et conflictuel de la condition humaine. Parallèlement, nous présenterons les incidences psychiques qui se traduisent par une « culture du narcissisme » suscitée notamment par diverses composantes de la société contemporaine. À travers une relecture de la condition humaine, Lasch préconise un correctif idéologique qui est axé sur les notions de limites et d’espoir et qui se trouve au sein de la tradition agraire populiste américaine du 19e siècle. Nous démontrerons ainsi comment ce retour en arrière est entamé dans le but de susciter un renouveau politique et identitaire au sein de la société. L’étude se conclura par une discussion sur la plausibilité de l’idéal populiste, tel que l’entend Lasch, à l’ère du 21e siècle.