Heterogeneous response dynamics in retinal ganglion cells: the interplay of predictive coding and adaptation.

To make efficient use of their limited signaling capacity, sensory systems often use predictive coding. Predictive coding works by exploiting the statistical regularities of the environment--specifically, by filtering the sensory input to remove its predictable elements, thus enabling the neural signal to focus on what cannot be guessed. To do this, the neural filters must remove the environmental correlations.

Physicians' awareness and attitudes toward decision aids for patients with cancer.

Purpose: Patient decision aids are interventions designed to help patients make deliberative choices about their treatment options and have been shown to significantly improve patient outcomes. Although considered optimal, decision aids are not widely used in clinical practice for cancer treatment. The objectives of this study are to determine physicians' awareness and use of decision aids, physicians' perceptions of the major barriers to the use of decision aids, and physician characteristics predictive of use of decision aids in clinical practice.

Maternal immunization with ovalbumin prevents neonatal allergy development and up-regulates inhibitory receptor Fc gamma RIIB expression on B cells.

Background: Preconception allergen immunization prevents neonatal allergen sensitization in mice by a complex interaction between regulatory cells/factors and antibodies. The present study assessed the influence of maternal immunization with ovalbumin (OVA) on the immune response of 3 day-old and 3 week-old offspring immunized or non-immunized with OVA and evaluated the effect of IgG treatment during fetal development or neonatal period.

Results: Maternal immunization with OVA showed increased levels of Fc gamma RIIb expression in splenic B cells of neonates, which were maintained for up to 3 weeks and not affected by additional postnatal OVA immunization.

Transcription within condensed chromatin: Steric hindrance facilitates elongation.

During eukaryotic transcription, RNA-polymerase activity generates torsional stress in DNA, having a negative impact on the elongation process. Using our previous studies of chromatin fiber structure and conformational transitions, we suggest that this torsional stress can be alleviated, thanks to a tradeoff between the fiber twist and nucleosome conformational transitions into an activated state named "reversome". Our model enlightens the origin of polymerase pauses, and leads to the counterintuitive conclusion that chromatin-organized compaction might facilitate polymerase progression.

Quality improvement capacity: a survey of hospital quality managers.

Background Skilled managers are an important component of quality improvement (QI) infrastructure, but there has been little evaluation of QI infrastructure, which is needed to guide enhancement of this capacity. Methods Quality managers at 97 acute care hospitals in Ontario, Canada, were surveyed by mail to describe how their roles were integrated with QI performance objectives. Binary and scaled responses were analysed quantitatively, and open-ended responses were analysed thematically.

Tobacco-related medical education and physician interventions with parents who smoke: Survey of Canadian family physicians and pediatricians.

Objective: To examine the relationship between physicians' tobacco-related medical training and physicians' confidence in their tobacco-related skills and smoking-related interventions with parents of child patients.

Design: Mailed survey.

Setting: Canada.

Effect of human rotavirus vaccine on severe diarrhea in African infants.

Background: Rotavirus is the most common cause of severe gastroenteritis among young children worldwide. Data are needed to assess the efficacy of the rotavirus vaccine in African children.

Methods: We conducted a randomized, placebo-controlled, multicenter trial in South Africa (3166 infants; 64.

CpG-induced Th1-type response in the downmodulation of early development of allergy and inhibition of B7 expression on T cells of newborn mice.

Introduction: Several differences have been described between neonatal and adult immune responses. The predisposition in early life to Th2-type response or tolerance makes it a susceptible period for infections and allergic sensitization.

Objective: The aim of this work was to evaluate the effects of CpG-containing oligodeoxynucleotides on neonatal and adult immunization with ovalbumin and Blomia tropicalis extract and compare the CpG effects on B and T cells of neonatal and adult mice.

Long-term stability of visual pattern selective responses of monkey temporal lobe neurons.

Many neurons in primate inferotemporal (IT) cortex respond selectively to complex, often meaningful, stimuli such as faces and objects. An important unanswered question is whether such response selectivity, which is thought to arise from experience-dependent plasticity, is maintained from day to day, or whether the roles of individual cells are continually reassigned based on the diet of natural vision. We addressed this question using microwire electrodes that were chronically implanted in the temporal lobe of two monkeys, often allowing us to monitor activity of individual neurons across days.

Self-directed learning needs, patterns, and outcomes among general surgeons.

Introduction: To explore the relationship between self-directed learning (SDL) needs, patterns, barriers, and outcomes among nonacademic general surgeons.

Methods: Participants dictated details of SDL episodes associated with cancer patient management from October 2007 to March 2008. Transcripts were coded thematically.

Influenza-associated cystic fibrosis pulmonary exacerbations.

Background: Although cystic fibrosis (CF) is the most common inherited respiratory disease, the burden of influenza among individuals with CF is not well characterized.

Methods: We used the CF Foundation Patient Registry to determine the relationship between pulmonary exacerbation incidence rate and influenza virus season from July 2003 through June 2007. The outcome of interest, pulmonary exacerbation, was defined as treatment of a respiratory illness with IV antibiotics.

Predictive validity and measurement issues in documenting quit intentions in population surveillance studies.

Introduction: Discrete classification of smokers by intention to quit is desirable in many public health and clinical settings.

Methods: Two methodological studies examine measurement properties of measures of discrete-time intention to quit smoking used in population-based tobacco surveillance surveys: an ecological comparison of rates of positive intention in relation to the form of measure used and a prospective analysis examining predictive validity of self-reported quit intentions using multiple possible points of dichotomization of an ordinal measure of intention to quit. The prospective analysis used a repeated measures design and follow-up to 1 year for 2,047 smokers in the Ontario Tobacco Survey cohort.

Sepsis is a major predictor of failure after ileal pouch-anal anastomosis.

Purpose: This study aimed to determine the risk of ileal pouch-anal anastomosis failure and factors predictive of failure overall and in patients with septic complications.

Methods: Patients were identified through a prospectively maintained patient registry. All patients registered in the Mount Sinai Hospital Inflammatory Bowel Disease database who had an ileal pouch-anal anastomosis for more than 12 months were included in the study.

Subpopulations of neurons in visual area v2 perform differentiation and integration operations in space and time.

The interconnected areas of the visual system work together to find object boundaries in visual scenes. Primary visual cortex (V1) mainly extracts oriented luminance boundaries, while secondary visual cortex (V2) also detects boundaries defined by differences in texture. How the outputs of V1 neurons are combined to allow for the extraction of these more complex boundaries in V2 is as of yet unclear.

The influence of muscle load on tibiofemoral knee kinematics.

A comparative kinematics study was conducted on six cadaver limbs, comparing tibiofemoral kinematics in five conditions: unloaded, under a constant 130 N ankle load with a variable quadriceps load, with and without a simultaneous constant 50 N medial and lateral hamstrings load. Kinematics were described as translation of the projected centers of the medial (MFT) and lateral femoral condyles (LFT) in the horizontal plane of the tibia, and tibial axial rotation (TR) as a function of flexion angle. In passive conditions, the tibia rotated internally with increasing flexion to an average of -16 degrees (range: -12/-20 degrees , SD = 3.

Assessment of variation throughout the year in the incidence of idiopathic sudden sensorineural hearing loss.

Objective: This study was conducted to determine whether the incidence of idiopathic sudden sensorineural hearing loss (ISSHL) varies throughout the year.

Study Design: This study is a retrospective case review.

Setting: This study was conducted at a tertiary referral center within a teaching hospital.

Treatment of symptomatic cartilage defects of the knee: characterized chondrocyte implantation results in better clinical outcome at 36 months in a randomized trial compared to microfracture.

Background: Damaged articular cartilage has limited capacity for self-repair. Autologous chondrocyte implantation using a characterized cell therapy product results in significantly better early structural repair as compared with microfracture in patients with symptomatic joint surface defects of the femoral condyles of the knee.

Purpose: To evaluate clinical outcome at 36 months after characterized chondrocyte implantation (CCI) versus microfracture (MF).

Vendor compliance with Ontario's tobacco point of sale legislation.

Objective: On May 31, 2006, Ontario joined a small group of international jurisdictions to implement legislative restrictions on tobacco point of sale promotions. This study compares the presence of point of sale promotions in the retail tobacco environment from three surveys: one prior to and two following implementation of the legislation.

Method: Approximately 1,575 tobacco vendors were randomly selected for each survey.

Rotavirus vaccines for infants in developing countries in Africa and Asia: considerations from a world health organization-sponsored consultation.

The World Health Organization (WHO) and its international partners have prioritized the development of rotavirus vaccines for the past 3 decades. In November 2005, the WHO's Strategic Advisory Group of Experts first reviewed the clinical efficacy data from 2 new live attenuated oral rotavirus vaccines, which demonstrated excellent protective efficacy against severe rotavirus disease in regions where they were evaluated. Despite these successes, the WHO has urged the clinical evaluation of these vaccines in populations of Africa and Asia, where most of the deaths due to rotavirus occur, and has emphasized the need for ongoing postlicensure safety monitoring in countries introducing vaccines.

Laminar and orientation-dependent characteristics of spatial nonlinearities: implications for the computational architecture of visual cortex.

A full understanding of the computations performed in primary visual cortex is an important yet elusive goal. Receptive field models consisting of cascades of linear filters and static nonlinearities may be adequate to account for responses to simple stimuli such as gratings and random checkerboards, but their predictions of responses to complex stimuli such as natural scenes are only approximately correct. It is unclear whether these discrepancies are limited to quantitative inaccuracies that reflect well-recognized mechanisms such as response normalization, gain controls, and cross-orientation suppression or, alternatively, imply additional qualitative features of the underlying computations.

Comparative efficacy of inactivated and live attenuated influenza vaccines.

Background: The efficacy of influenza vaccines may vary from year to year, depending on a variety of factors, and may differ for inactivated and live attenuated vaccines.

Methods: We carried out a randomized, double-blind, placebo-controlled trial of licensed inactivated and live attenuated influenza vaccines in healthy adults during the 2007-2008 influenza season and estimated the absolute and relative efficacies of the two vaccines.

Results: A total of 1952 subjects were enrolled and received study vaccines in the fall of 2007.

Balance between early life tolerance and sensitization in allergy: dependence on the timing and intensity of prenatal and postnatal allergen exposure of the mother.

Allergens can be maternally transferred to the fetus or neonate, though it is uncertain how this initial allergen exposure may impact the development of allergy responses. To evaluate the roles of timing and level of maternal allergen exposure in the early life sensitization of progeny, female BALB/c mice were given ovalbumin (OVA) orally during pregnancy, lactation or weekly at each stage to investigate the immunoglobulin E (IgE) antibody production and cellular responsiveness of their offspring. Exposure to OVA during pregnancy was also evaluated in OVA-specific T-cell receptor (TCR) transgenic (DO11.

In vivo kinematics after a cruciate-substituting TKA.

Unlabelled: Patterns of motion in the native knee show substantial variability. Guided motion prosthetic designs offer stability but may limit natural variability. To assess these limits, we therefore determined the in vivo kinematic patterns for patients having a cruciate-substituting TKA of one design and determined the intersurgeon variability associated with a guided-motion prosthetic design.