Can the theory of "whitening" explain the center-surround properties of retinal ganglion cell receptive fields?

To account for the spatial and temporal response properties of the retina, a number of studies have proposed that these properties serve to "whiten" the visual input. In particular, it has been argued that the sensitivity of retinal ganglion cells is matched to the spatial frequency spectrum of natural scenes, resulting in a flattened or "whitened" response spectrum across a range of frequencies. However, we argue that there are two distinct hypotheses regarding the flattening of the spectrum.

Postoperative endophthalmitis: caution is the watchword.

Postoperative endophthalmitis is the most feared complication following cataract surgery. It can be caused by infection entering the eye during surgery or by inadequately cleaned instruments. Sterile phaco handpieces might retain remnants of soft lens matter or visco-elastic which might later contaminate other patients, causing inflammation in their eyes.

Cost-effectiveness of neonatal extracorporeal membrane oxygenation based on 7-year results from the United Kingdom Collaborative ECMO Trial.

Objective: To assess the long-term cost-effectiveness of extracorporeal membrane oxygenation (ECMO) for mature newborn infants with severe respiratory failure.

Methods: A prospective economic evaluation was conducted alongside a pragmatic randomized, controlled trial in which 185 infants were randomly allocated to ECMO (n = 93) or conventional management (n = 92) and then followed up to 7 years of age. Information about their use of health services during the follow-up period was combined with unit costs (pound sterling, 2002-2003 prices) to obtain a net cost per child.

United Kingdom collaborative randomized trial of neonatal extracorporeal membrane oxygenation: follow-up to age 7 years.

Objective: The UK Collaborative ECMO trial provided an opportunity to describe mortality and morbidity associated with a neonatal ECMO policy compared with conventional management. The improved survival in the ECMO group was not offset by an increase in disability at 4 years, but the children were too young to assess educational and other longer-term impacts. The objective of this study was to assess the longer-term impact of these policies at age 7 years.

The influence of prior choices on current choice.

Three pigeons chose between random-interval (RI) and tandem, continuous-reinforcement, fixed-interval (crf-FI) reinforcement schedules by pecking either of two keys. As long as a pigeon pecked on the RI key, both keys remained available. If a pigeon pecked on the crf-FI key, then the RI key became unavailable and the crf-FI timer began to time out.

Socioeconomic inequalities in very preterm birth rates.

Aims: To investigate the extent of socioeconomic inequalities in the incidence of very preterm birth over the past decade.

Methods: Ecological study of all 549 618 births in the former Trent health region, UK, from 1 January 1994 to 31 December 2003. All singleton births of 22(+0) to 32(+6) weeks gestation (7 185 births) were identified from population surveys of neonatal services and stillbirths.

What image properties regulate eye growth?

The growth of the eye, unlike other parts of the body, is not ballistic. It is guided by visual feedback with the eventual aim being optimal focus of the retinal image or emmetropization . It has been shown in animal models that interference with the quality of the retinal image leads to a disruption to the normal growth pattern, resulting in the development of refractive errors and defocused retinal images .

Performance evaluation of the immature granulocyte parameter on the Sysmex XE-2100 automated hematology analyzer.

Recently, St. Anthony's Medical Center Laboratory (SAMC) in St. Louis, Missouri, installed a new automated hematology analyzer, the Sysmex XE-2100.

Follow up of infants following discharge from the neonatal unit: structure and process.

Reviewing high risk infants after discharge to provide ongoing clinical care and to monitor later outcomes is an important role for neonatologists and paediatricians. Clinical need is the primary reason for such follow up but the process does provide additional opportunities, for example collecting information on later outcomes is vital for health care commissioning, and to determine the longer term effects of new medical treatments. Parents welcome the early identification of any problems in their infant and the opportunity for early intervention may improve outcomes in some circumstances.

A dose response study of inhaled nitric oxide in hypoxic respiratory failure in preterm infants.

Background: Inhaled nitric oxide (iNO) is used widely in newborn infants with hypoxic respiratory failure, despite the known and theoretical toxicity of iNO, and a relative lack of information about appropriate doses.

Aim: To determine whether a dose-response relationship existed for iNO in preterm infants.

Design: A four-period, four-dose, cross-over design was used with iNO given for 15 min in a randomised sequence in concentrations of 5, 10, 20 and 40 parts per million (ppm), with a minimum 5 min wash-out period.

Planktonic foraminifera of the California Current reflect 20th-century warming.

It is currently unclear whether observed pelagic ecosystem responses to ocean warming, such as a mid-1970s change in the eastern North Pacific, depart from typical ocean variability. We report variations in planktonic foraminifera from varved sediments off southern California spanning the past 1400 years. Increasing abundances of tropical/subtropical species throughout the 20th century reflect a warming trend superimposed on decadal-scale fluctuations.

The perception of emotion from body movement in point-light displays of interpersonal dialogue.

We examined whether it is possible to identify the emotional content of behaviour from point-light displays where pairs of actors are engaged in interpersonal communication. These actors displayed a series of emotions, which included sadness, anger, joy, disgust, fear, and romantic love. In experiment 1, subjects viewed brief clips of these point-light displays presented the right way up and upside down.

Developmental outcome in newborn infants treated for acute respiratory failure with extracorporeal membrane oxygenation: present experience.

Objective: To describe the later health status of newborn infants who received extracorporeal membrane oxygenation (ECMO) for acute respiratory failure in the era after the UK ECMO trial.

Design: Prospective follow up study of newborn infants who received ECMO at a single centre between January 1997 and January 2001.

Setting: Departments of ECMO and Paediatric Intensive Care, University Hospitals of Leicester.

Cytokine imbalance in infants receiving extracorporeal membrane oxygenation for respiratory failure.

Background: It is likely that the imbalance between the pro- and anti-inflammatory cytokines will determine the outcome in infants with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO).

Aims: We determined if there was an imbalance between pro- and anti-inflammatory cytokines in serial bronchoalveolar lavage (BAL) fluid obtained from survivors and non-survivors of ECMO.

Methods: We therefore measured the cellular changes and the molar ratios of pro-inflammatory and anti-inflammatory cytokines in serial BAL fluid obtained from survivors and non-survivors of ECMO.

Bioinformatics and data management support for environmental genomics.

The UK Natural Environment Research Council has funded the creation of a dedicated bioinformatics centre as part of a £26m Environmental Genomics initiative.

Comparison of glyburide and insulin for the management of gestational diabetes in a large managed care organization.

Objective: This study was undertaken to compare the use of glyburide with insulin for the treatment of gestational diabetes mellitus (GDM) unresponsive to diet therapy.

Study Design: A retrospective study was performed among women with singleton pregnancies who had GDM diagnosed, with fasting plasma glucose 140 mg/dL or less on glucose tolerance testing, between 12 and 34 weeks who failed diet therapy from 1999 to 2002. We identified 584 women and compared those treated with insulin between 1999 and 2000 with women treated with glyburide between 2001 and 2002.

Databases and software for the comparison of prokaryotic genomes.

The explosion in the number of complete genomes over the past decade has spawned a new and exciting discipline, that of comparative genomics. To exploit the full potential of this approach requires the development of novel algorithms, databases and software which are sophisticated enough to draw meaningful comparisons between complete genome sequences and are widely accessible to the scientific community at large. This article reviews progress towards the development of computational tools and databases for organizing and extracting biological meaning from the comparison of large collections of genomes.

How close are we to understanding v1?

A wide variety of papers have reviewed what is known about the function of primary visual cortex. In this review, rather than stating what is known, we attempt to estimate how much is still unknown about V1 function. In particular, we identify five problems with the current view of V1 that stem largely from experimental and theoretical biases, in addition to the contributions of nonlinearities in the cortex that are not well understood.

Neonatal Ventilation With Inhaled Nitric Oxide Versus Ventilatory Support Without Inhaled Nitric Oxide for Preterm Infants With Severe Respiratory Failure: the INNOVO multicentre randomised controlled trial (ISRCTN 17821339).

Background: Although inhaled nitric oxide (iNO) may be a promising treatment for newborn infants with severe respiratory failure, the results from 3 previous small trials were inconclusive.

Methods: Infants of <34 weeks' gestation, <28 days old, and with severe respiratory failure requiring ventilatory support were randomized to receive or not receive iNO. The study was not blinded.

Analysis of local orientation gradients in deformed single crystals.

Grain fragmentation and local orientation gradients in deformed single crystals are characterized using electron backscatter diffraction (EBSD) to obtain statistically reliable information. Interrogation of the dislocation substructure is accomplished by extracting information gleaned from small point-to-point misorientations as measured by EBSD. Along with an estimate of the geometrically necessary dislocation (GND) content, the point-to-point deviation from an average grain orientation is described by an orientation difference vector defined in Rodrigues space.