Lens rigidity with trapped geodesics in two dimensions

We consider the scattering and lens rigidity of compact surfaces with boundary that have a trapped geodesic. In particular we show that the flat cylinder and the flat M\"obius strip are determined by their lens data. We also see by example that the flat M\"obius strip is not determined by it's scattering data. We then consider the case of negatively curved cylinders with convex boundary and show that they are lens rigid.Comment: 12 pages, 2 figure

Apolipoprotein E allele 4 effects on Single-Subject Gray Matter Networks in Mild Cognitive Impairment.

There is evidence that gray matter networks are disrupted in Mild Cognitive Impairment (MCI) and associated with cognitive impairment and faster disease progression. However, it remains unknown how these alterations are related to the presence of Apolipoprotein E isoform E4 (ApoE4), the most prominent genetic risk factor for late-onset Alzheimer's disease (AD). To investigate this topic at the individual level, we explore the impact of ApoE4 and the disease progression on the Single-Subject Gray Matter Networks (SSGMNets) using the graph theory approach. Our data sample comprised 200 MCI patients selected from the ADNI database, classified as non-Converters and Converters (will progress into AD). Each group included 50 ApoE4-positive ('Carriers', ApoE4 + ) and 50 ApoE4-negative ('non-Carriers', ApoE4-). The SSGMNets were estimated from structural MRIs at two-time points: baseline and conversion. We investigated whether altered network topological measures at baseline and their rate of change (RoC) between baseline and conversion time points were associated with ApoE4 and disease progression. We also explored the correlation of SSGMNets attributes with general cognition score (MMSE), memory (ADNI-MEM), and CSF-derived biomarkers of AD (Aβ42, T-tau, and P-tau). Our results showed that ApoE4 and the disease progression modulated the global topological network properties independently but not in their RoC. MCI converters showed a lower clustering index in several regions associated with neurodegeneration in AD. The SSGMNets' topological organization was revealed to be able to predict cognitive and memory measures. The findings presented here suggest that SSGMNets could indeed be used to identify MCI ApoE4 Carriers with a high risk for AD progression

El síndrome de masa - reporte de una familia

El síndrome de Masa, Síndrome de Bianchine-Lewis, Síndrome de Gareis- Masson, Síndrome de retardo mental ligado al X y pulgar incluido, retardo mental con pulgar en aducción o retardo mental con pulgar incluido congénito, Síndrome de CRASH; es una forma de retardo mental raro, de etiología recesiva ligada al X. Los criterios mayores de diagnóstico son: retardo mental, afasia, marcha arrastrando los pies y aducción de los pulgares, de donde viene su nombre por las siglas en ingles (Mental retardation, Aphasia, Shuffling gait, Adducted thumbs- MASA). Elgen mutado es L1CAM que codifica la Molécula de Adhesión Celular L1, y mapea en Xq28. Este gen es el mismo de la hidrocefalia ligada al X y de la Paraplejía Espástica Complicada tipo 1. La mayoría de los pacientes son varones, sin embargo existen familias con mujeres afectadas, peroen general las mujeres portadoras son asintomáticas. La variabilidad clínica inter e intra familiar de los afectados es amplia. Reportamos el caso de un paciente del sexo masculino de 10 meses de edad, producto del primer embarazo de una pareja joven, no consanguínea, que consulta por retraso del desarrollo sicomotor y aducción de ambos pulgares. En la Tomografía computarizada del cráneo se observa: ventrículos laterales muy agrandados y disgenesia del cuerpo calloso. Su estudio cromosómico es normal. Se trata de una familia en la cual dos hermanos de la madre y un hermano de la abuela materna también están afectados por retardo mental, pulgares en aducción y marcha arrastrada. En estos pacientes no se realizó el estudio cromosómico y no tenían diagnóstico hasta este momento. En este trabajo se resalta la importancia del diagnóstico certero de patologías genéticas en países subdesarrollados a través del conocimiento de las manifestaciones clínicas de las patologías, aunque no dispongamos de medios de diagnóstico más avanzados. En esta familia el diagnóstico recién fue realizado en el propósito y por lo tanto la misma no pudo beneficiarse de un correcto asesoramiento genético

Síndrome femoral facial en un hijo de madre con diabetes gestacional

El Síndrome Femoral Facial (SFF) o Síndrome de Hipoplasia Femoral, Facies Inusual (SHFFI), es una asociación rara de anomalías femorales y faciales. La diabetes materna ha sido implicada como agente causal. En este trabajo se describe a un niño con el síndrome de hipoplasia femoral, facies inusual. El mismo tiene las características faciales típicas, de fisuras palpebrales deinclinación mongoloide, filtrum largo con labio superior fino, alaenasi hipoplásicos y micrognatia. Presentaba también anomalias de miembros superiores, costillas, vértebras, y miembros inferiores. Insuficiencia de la válvula tricúspide y defecto de tubo neural. No hay antecedentes familiares. Se le diagnóstico diabetes gestacional a la madre, a las 20 semanas se reporta este caso para resaltar y reforzar la relación de la diabetes gestacional con el Síndrome Femoral Facial

Spatial resolution and imaging encoding fMRI settings for optimal cortical and subcortical motor somatotopy in the human brain

There is much controversy about the optimal trade-off between blood-oxygen-level-dependent (BOLD) sensitivity and spatial precision in experiments on brain’s topology properties using functional magnetic resonance imaging (fMRI). The sparse empirical evidence and regional specificity of these interactions pose a practical burden for the choice of imaging protocol parameters. Here, we test in a motor somatotopy experiment the impact of fMRI spatial resolution on differentiation between body part representations in cortex and subcortical structures. Motor somatotopy patterns were obtained in a block-design paradigm and visually cued movements of face, upper and lower limbs at 1.5, 2, and 3 mm spatial resolution. The degree of segregation of the body parts’ spatial representations was estimated using a pattern component model. In cortical areas, we observed the same level of segregation between somatotopy maps across all three resolutions. In subcortical areas the degree of effective similarity between spatial representations was significantly impacted by the image resolution. The 1.5 mm 3D EPI and 3 mm 2D EPI protocols led to higher segregation between motor representations compared to the 2 mm 3D EPI protocol. This finding could not be attributed to differential BOLD sensitivity or delineation of functional areas alone and suggests a crucial role of the image encoding scheme – i.e., 2D vs. 3D EPI. Our study contributes to the field by providing empirical evidence about the impact of acquisition protocols for the delineation of somatotopic areas in cortical and sub-cortical brain regions

Chaperone-Mediated Protein Disaggregation Triggers Proteolytic Clearance of Intra-nuclear Protein Inclusions

The formation of insoluble inclusions in the cytosol and nucleus is associated with impaired protein homeostasis and is a hallmark of several neurodegenerative diseases. Due to the absence of the autophagic machinery, nuclear protein aggregates require a solubilization step preceding degradation by the 26S proteasome. Using yeast, we identify a nuclear protein quality control pathway required for the clearance of protein aggregates. The nuclear J-domain protein Apj1 supports protein disaggregation together with Hsp70 but independent of the canonical disaggregase Hsp104. Disaggregation mediated by Apj1/Hsp70 promotes turnover rather than refolding. A loss of Apj1 activity uncouples disaggregation from proteasomal turnover, resulting in accumulation of toxic soluble protein species. Endogenous substrates of the Apj1/Hsp70 pathway include both nuclear and cytoplasmic proteins, which aggregate inside the nucleus upon proteotoxic stress. These findings demonstrate the coordinated activity of the Apj1/Hsp70 disaggregation system with the 26S proteasome in facilitating the clearance of toxic inclusions inside the nucleus

Insecurity for compact surfaces of positive genus

A pair of points in a riemannian manifold $M$ is secure if the geodesics between the points can be blocked by a finite number of point obstacles; otherwise the pair of points is insecure. A manifold is secure if all pairs of points in $M$ are secure. A manifold is insecure if there exists an insecure point pair, and totally insecure if all point pairs are insecure. Compact, flat manifolds are secure. A standing conjecture says that these are the only secure, compact riemannian manifolds. We prove this for surfaces of genus greater than zero. We also prove that a closed surface of genus greater than one with any riemannian metric and a closed surface of genus one with generic metric are totally insecure.Comment: 37 pages, 11 figure

Diagnóstico prenatal de ectrodactilia, por ecografía, en dos hermanos

La Ectrodactilia una malformación congénita rara caracterizada por la ausencia de dígitos y tiene una amplia variedad de expresión. Esta anomalía puede ser esporádica o asociada a síndromes genéticos y no genéticos, como la Ectrodactilia autosómica dominante y el Síndrome deEctrodactília y displasia ectodérmica y paladar hendido. En este trabajo presentamos los casos de dos hermanos con el diagnóstico prenatal de ectrodactilía por ecografía del 2º trimestre, en ambos casos. El primer embarazo resultó en un feto muerto con ectrodactilia de ambas manos y ambos pies y estenosis de cordón umbilical. El segundo embarazo, en el nacimiento de un niño de sexo masculino con agenesia de mano izquierda y ectrodactília de mano derecha y ambos pies. Se resalta la importancia de un examen exhaustivo de manos y pies fetales, en la ecografía del segundo trimestre para así realizar más y mayores diagnósticos de malformaciones de manos y pies

Treatment of heart failure with autologous skeletal myoblasts

The management of patients with heart failure is a daily challenge for cardiologists and cardiac surgeons. Pharmacotherapy, atrio-biventricular resynchronization, myocardial revascularization, valve repair techniques, latissimus dorsi cardiomyoplasty, acorn cardiac support device, heart transplantation and mechanical assist devices do not cover all the needs. The recent progress in cellular and molecular biology allows the development of new therapies for heart failure. Transplantation of Autologous Cells: One of the most innovative consists in the transplantation of autologous ex-vivo expanded cells into the myocardium for heart muscle regeneration. This approach is called “cellular cardiomyoplasty”