Neuronal Basis of the Motion Aftereffect Reconsidered

AbstractSeveral fMRI studies have reported MT+ response increases correlated with perception of the motion aftereffect (MAE). However, attention can strongly affect MT+ responses, and subjects may naturally attend more to the MAE than control trials without MAE. We found that requiring subjects to attend to motion on both MAE and control trials produced equal levels of MT+ response, suggesting that attention may have confounded the interpretation of previous experiments; in our data, attention accounts for the entire effect. After eliminating this confound, we observed that direction-selective motion adaptation produced a direction-selective imbalance in MT+ responses (and earlier visual areas), and yielded a corresponding asymmetry in speed discrimination thresholds. These findings provide physiological evidence that population level response imbalances underlie the MAE, and quantify the relative proportions of direction-selective neurons across human visual areas

A Model for Transient Oxygen Delivery in Cerebral Cortex

Popular hemodynamic brain imaging methods, such as blood oxygen-level dependent functional magnetic resonance imaging (BOLD fMRI), would benefit from a detailed understanding of the mechanisms by which oxygen is delivered to the cortex in response to brief periods of neural activity. Tissue oxygen responses in visual cortex following brief visual stimulation exhibit rich dynamics, including an early decrease in oxygen concentration, a subsequent large increase in concentration, and substantial late-time oscillations (“ringing”). We introduce a model that explains the full time-course of these observations made by Thompson et al. (2003). The model treats oxygen transport with a set of differential equations that include a combination of flow and diffusion in a three-compartment (intravascular, extravascular, and intracellular) system. Blood flow in this system is modeled using the impulse response of a lumped linear system that includes an inertive element; this provides a simple biophysical mechanism for the ringing. The model system is solved numerically to produce excellent fits to measurements of tissue oxygen. The results give insight into the dynamics of cerebral oxygen transfer, and can serve as the starting point to understand BOLD fMRI measurements

An enhanced platform for cell electroporation: controlled delivery and electrodes functionalization

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Low expression of the putative tumour suppressor spinophilin is associated with higher proliferative activity and poor prognosis in patients with hepatocellular carcinoma

BACKGROUND: Spinophilin, a multifunctional intracellular scaffold protein, is reduced in certain types of cancer and is regarded as a novel putative tumour suppressor protein. However, the role of spinophilin in hepatocellular carcinoma (HCC) has never been explored before. METHODS: In this study, we determined for the first time the expression pattern of spinophilin in human HCC by immunohistochemistry and quantitative reverse transcriptase–PCR analysis. In addition, we performed immunohistochemical analysis of p53, p14(ARF) and the proliferation marker Ki-67. Kaplan–Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome. Small interfering RNA (siRNA) was used to silence spinophilin and to explore the effects of reduced spinophilin expression on cellular growth. RESULTS: In our study, complete loss of spinophilin immunoreactivity was found in 44 of 104 HCCs (42.3%) and reduced levels were found in an additional 37 (35.6%) cases. After adjusting for other prognostic factors, multivariate Cox regression analysis identified low expression of spinophilin as an independent prognostic factor with respect to disease-free (hazard ratio (HR)=1.8; 95% confidence interval (CI)=1.04–3.40; P=0.043) and cancer-specific survival (HR=2.0; CI=1.1–3.8; P=0.025). Reduced spinophilin expression significantly correlated with higher Ki-67 index in HCC (P=0.014). Reducing spinophilin levels by siRNA induced a higher cellular growth rate and increased cyclin D2 expression in tumour cells (P<0.05). CONCLUSION: This is the first study of the expression pattern and distribution of spinophilin in HCC. According to our data, the loss of spinophilin is associated with higher proliferation and might be useful as a prognostic marker in patients with HCC

Increased neutrophil-lymphocyte ratio is a poor prognostic factor in patients with primary operable and inoperable pancreatic cancer

Background: The neutrophil-lymphocyte ratio (NLR) has been proposed as an indicator of systemic inflammatory response. Previous findings from small-scale studies revealed conflicting results about its independent prognostic significance with regard to different clinical end points in pancreatic cancer (PC) patients. Therefore, the aim of our study was the external validation of the prognostic significance of NLR in a large cohort of PC patients. Methods: Data from 371 consecutive PC patients, treated between 2004 and 2010 at a single centre, were evaluated retrospectively. The whole cohort was stratified into two groups according to the treatment modality. Group 1 comprised 261 patients with inoperable PC at diagnosis and group 2 comprised 110 patients with surgically resected PC. Cancer-specific survival (CSS) was assessed using the Kaplan–Meier method. To evaluate the independent prognostic significance of the NLR, the modified Glasgow prognostic score (mGPS) and the platelet-lymphocyte ratio univariate and multivariate Cox regression models were applied. Results: Multivariate analysis identified increased NLR as an independent prognostic factor for inoperable PC patients (hazard ratio (HR)=2.53, confidence interval (CI)=1.64–3.91, P<0.001) and surgically resected PC patients (HR=1.61, CI=1.02–2.53, P=0.039). In inoperable PC patients, the mGPS was associated with poor CSS only in univariate analysis (HR=1.44, CI=1.04–1.98). Conclusion: Risk prediction for cancer-related end points using NLR does add independent prognostic information to other well-established prognostic factors in patients with PC, regardless of the undergoing therapeutic modality. Thus, the NLR should be considered for future individual risk assessment in patients with PC

REDIENTE: historia clínica odontológica ubicua con indicadores de calidad de servicios y evaluación epidemiológica

REDIENTE es un registro clínico en una base de datos accesible en internet, con vocación nacional y manejo local por parte de los odontólogos en sus consultorios individuales o en instituciones. Un carnet REDIENTE con copia de la historia clínica queda en poder del paciente que une todos los eventos en un hilo documental coherente. Las variables de la Historia Clínica Odontológica (HCO) son las indispensables para certificar una buena atención. Los indicadores de REDIENTE sobre poblaciones permiten describir situaciones de salud bucal, evaluar calidad de atención y hacer el seguimiento docente. REDIENTE respeta la legislación sobre protección de datos personales del paciente.REDIENTE is an interdisciplinary solution for a multifaceted problem: standardization of dental care documentation, creation of a teaching supervision tool and designing a management application for dental care quality assurance. Distribution of data and information are addressed by giving the patient a copy of the basic record, the Dental Clinical Record (HCO for the Spanish “Historia Clínica Odontológica”) and by designing a web application. HCO contains the skeleton of dental care record including items of procedures performed, complications, office dates and periodic odontogram. REDIENTE displays quality of care and learning indicators as selective queries to the database. www.rediente.org.uy.Sociedad Argentina de Informática e Investigación Operativ

REDIENTE: historia clínica odontológica ubicua con indicadores de calidad de servicios y evaluación epidemiológica

REDIENTE es un registro clínico en una base de datos accesible en internet, con vocación nacional y manejo local por parte de los odontólogos en sus consultorios individuales o en instituciones. Un carnet REDIENTE con copia de la historia clínica queda en poder del paciente que une todos los eventos en un hilo documental coherente. Las variables de la Historia Clínica Odontológica (HCO) son las indispensables para certificar una buena atención. Los indicadores de REDIENTE sobre poblaciones permiten describir situaciones de salud bucal, evaluar calidad de atención y hacer el seguimiento docente. REDIENTE respeta la legislación sobre protección de datos personales del paciente.REDIENTE is an interdisciplinary solution for a multifaceted problem: standardization of dental care documentation, creation of a teaching supervision tool and designing a management application for dental care quality assurance. Distribution of data and information are addressed by giving the patient a copy of the basic record, the Dental Clinical Record (HCO for the Spanish “Historia Clínica Odontológica”) and by designing a web application. HCO contains the skeleton of dental care record including items of procedures performed, complications, office dates and periodic odontogram. REDIENTE displays quality of care and learning indicators as selective queries to the database. www.rediente.org.uy.Sociedad Argentina de Informática e Investigación Operativ

REDIENTE: historia clínica odontológica ubicua con indicadores de calidad de servicios y evaluación epidemiológica

REDIENTE es un registro clínico en una base de datos accesible en internet, con vocación nacional y manejo local por parte de los odontólogos en sus consultorios individuales o en instituciones. Un carnet REDIENTE con copia de la historia clínica queda en poder del paciente que une todos los eventos en un hilo documental coherente. Las variables de la Historia Clínica Odontológica (HCO) son las indispensables para certificar una buena atención. Los indicadores de REDIENTE sobre poblaciones permiten describir situaciones de salud bucal, evaluar calidad de atención y hacer el seguimiento docente. REDIENTE respeta la legislación sobre protección de datos personales del paciente.REDIENTE is an interdisciplinary solution for a multifaceted problem: standardization of dental care documentation, creation of a teaching supervision tool and designing a management application for dental care quality assurance. Distribution of data and information are addressed by giving the patient a copy of the basic record, the Dental Clinical Record (HCO for the Spanish “Historia Clínica Odontológica”) and by designing a web application. HCO contains the skeleton of dental care record including items of procedures performed, complications, office dates and periodic odontogram. REDIENTE displays quality of care and learning indicators as selective queries to the database. www.rediente.org.uy.Sociedad Argentina de Informática e Investigación Operativ

Visual Clutter Causes High-Magnitude Errors

Perceptual decisions are often made in cluttered environments, where a target may be confounded with competing “distractor” stimuli. Although many studies and theoretical treatments have highlighted the effect of distractors on performance, it remains unclear how they affect thequality of perceptual decisions. Here we show that perceptual clutter leads not only to an increase in judgment errors, but also to an increase in perceived signal strength and decision confidence on erroneous trials. Observers reported simultaneously the direction and magnitude of the tilt of a target grating presented either alone, or together with vertical distractor stimuli. When presented in isolation, observers perceived isolated targets as only slightly tilted on error trials, and had little confidence in their decision. When the target was embedded in distractors, however, they perceived it to be strongly tilted on error trials, and had high confidence of their (erroneous) decisions. The results are well explained by assuming that the observers' internal representation of stimulus orientation arises from a nonlinear combination of the outputs of independent noise-perturbed front-end detectors. The implication that erroneous perceptual decisions in cluttered environments are made with high confidence has many potential practical consequences, and may be extendable to decision-making in general