Exploring the Effects of Offline Paradigms and Feature Extraction Techniques on Performance of Motor Imagery Brain-Computer Interface: Longitudinal Pilot Study.

Motor Imagery (MI) Brain-Computer Interface (BCI) is a popular way of allowing disabled and healthy individuals to use brain signals to communicate with their environment, despite the technical and human factor challenges that affect MI BCI classification performance. This study explored the influence of paradigm choice and phase synchronization-based features on classification performance by comparing primary datasets to older supplemental datasets. Area Under the Curve (AUC) Receiver Operating Characteristics (ROC) curve was the metric for classification performance. Results showed that using both advanced paradigms and features significantly improved both classification and usability; TD-CSP-wPLI (16-30Hz) and S-CSP-wPLI (12-15Hz) frequency bands produced the most noticeable change in performance.

The effect of chronic corticosterone on fear learning and memory depends on dose and the testing protocol.

Chronic exposure to the stress hormone corticosterone (CORT) is known to alter plasticity within hippocampal and amygdalar circuits that mediate fear learning and memory. The purpose of this experiment was to clarify the effects of chronic CORT on Pavlovian fear conditioning, which is dependent on intact hippocampal and amygdalar activity. In particular, we assessed whether the effect of chronic CORT on fear learning and memory is influenced by two factors-the dose of CORT and the order in which rats are tested for freezing to context versus tone cues. Male Long-Evans rats received low-dose CORT (5mg/kg), high-dose CORT (40mg/kg), or vehicle injections once daily for 21days. On day 22, the rats were trained in a fear-conditioning paradigm. On days 23 and 24, the rats were tested for the retrieval of fear memories to context and tone cues in a counterbalanced way-half the rats received context testing on day 23 and then tone testing on day 24 and half the rats received tone testing on day 23 followed by context testing on day 24. Our results revealed dose-dependent effects of CORT on memory retrieval: Rats injected with high-dose CORT froze significantly more than control rats to both context and tone cues regardless of what testing day these cues were presented. However, rats injected with low-dose CORT froze significantly more than control rats to tone cues only. We also found an order effect in that the effects of CORT on freezing were greater on the second day of testing, regardless of whether that testing was to context or tones cues. This order effect may be due to a lack of extinction in the CORT rats. Overall, these results suggest a relationship between stress intensity and testing conditions that should be taken into account when assessing the effect of stress on fear memories.

Limited value of testing for intrinsic factor antibodies with negative gastric parietal cell antibodies in pernicious anaemia.

BACKGROUND: The appropriate testing strategy for diagnosing pernicious anaemia using gastric parietal cell (GPC) and/or intrinsic factor antibodies (IFA) is controversial. Intrinsic factor antibodies are found in only about 70% of cases. Indirect immunofluorescence screening for gastric parietal cell antibodies is more sensitive, labour intensive, and less specific. METHODS: The frequency of antibody positivity (IFA and/or GPC) was retrospectively examined in patients tested for both autoantibodies over a three-year period. It was investigated whether B12 levels were related to antibody status. These findings were validated in a prospective study of IFA in 91 GPC negative patients with low B12 levels. RESULTS: Of 847 samples identified in the retrospective study, 4 (0.47%) were positive for only intrinsic factor antibodies, 731 (86.3%) positive for GPC alone, and 112 (13.2%) for both. Student t test on log-transformed data showed B12 levels had no bearing on autoantibody status. 91 consecutive patients with low B12 levels were tested for both autoantibodies; all were negative for gastric parietal cell antibodies. Only one sample was positive for intrinsic factor antibody using the porcine intrinsic factor assay, but was negative by a human recombinant intrinsic factor-based ELISA. CONCLUSIONS: This study provides evidence that testing for gastric parietal cell antibodies is an appropriate screening test for pernicious anaemia, with intrinsic factor antibodies reserved for confirmatory testing or in patients with other autoantibodies that mask the GPC pattern; B12 levels are not related to autoantibody status.

Supratentorial juvenile pilocytic astrocytoma in a young adult with Silver-Russell syndrome.

Silver-Russell syndrome is a rare genetically heterogeneous disorder in which patients demonstrate intrauterine and postnatal growth retardation, triangular facies, excessive sweating during early childhood, late closure of the anterior fontanelle and skeletal asymmetry. An association with malignancy exists and only one previous intracranial tumour has been reported, a craniopharyngioma. We report the first case of Silver-Russell syndrome associated with a supratentorial juvenile pilocytic astrocytoma.

Paediatric empyema: a case report and literature review.

OBJECTIVE: To present a case of bilateral parapneumonic effusions in a child with Pneumococcal pneumonia and bacteraemia managed aggressively with early thoracotomies. The literature from peer reviewed journals is summarized and the different management strategies are discussed. METHODS: Articles and reviews from peer reviewed journals on the management of empyema in children and adults. RESULTS: Staging of parapneumonic pleural effusions is difficult to assess clinically and radiologically. Most cases can be successfully managed with simple chest tube drainage, plus appropriate antibiotic therapy. However, based on the available evidence for children, thoracotomy with decortication and direct drainage may provide the most effective treatment in terms of length of hospital stay and duration of chest tube insertion, when compared with video assisted thoracoscopic surgery (VATS) or chest tube drainage, with or without intrapleural fibrinolytic therapy. CONCLUSIONS: More conservative approaches to treatment of empyema may be appropriate initially to avoid the cosmetic and other disadvantages of thoracotomy. However, delayed surgical drainage increases morbidity and may potentially increase mortality.

Clostridium difficile associated severe enterocolitis: a feature of Hirschsprung's disease in a neonate presenting late.

We report a case of Hirschsprung's disease presenting late in the newborn period with severe enterocolitis and Clostridium difficile toxin detectable in the stool. Enterocolitis associated with Hirschsprung's disease is a potentially fatal complication that may occur at presentation or later in the life of an affected child. Its association with toxin-producing Clostridium difficile growth in the bowel may be under recognized, especially in newborns.

Reflections from organization science on the development of primary health care research networks.

In the UK, policy changes in primary health care research and development have led to the establishment of primary care research networks. These organizations aim to increase research culture, capacity and evidence base in primary care. As publicly funded bodies, these networks need to be accountable. Organizational science has studied network organizations including why and how they develop and how they function most effectively. This paper draws on organizational science to reflect on why primary care research networks appear to be appropriate for primary care research and how their structures and processes can best enable the achievement of their aims.

The productivity of primary care research networks.

Primary care research networks are being publicly funded in the United Kingdom to promote a culture of research and development in primary care. This paper discusses the organisational form of these networks and how their productivity can be evaluated, drawing on evidence from management science. An evaluation of a research network has to take account of the complexity of the organisation, the influence of its local context, and its stage of development. Output measures, such as number of research papers, and process measures, such as number of research meetings, may contribute to an evaluation. However, as networking relies on the development of informal, trust-based relationships, the quality of interactions within a network is of paramount importance for its success. Networks can audit and reflect on their success in promoting such relationships and a more formal qualitative evaluation by an independent observer can document their success to those responsible for funding.

Vocal symptoms in Parkinson disease treated with levodopa. A case report.

This is a report of a patient with unusually severe hoarseness in the absence of vocal fold pathology demonstrating Parkinson disease as one of the neurological diseases in which vocal symptoms occur. Although it is classifiably a severe, progressive, degenerative disorder, the popularity of pharmacotherapy for Parkinson disease during the past decade has resulted in improved functionality for an undetermined course of time in most patients. The classically described deterioration of speech ad voice may develop in a variant manner difficult to distinguish as disease-related, as this case report illustrates. An explanation of the hoarseness based on dyssynchronous vocal fold motion related to the disease is suggested by the acoustic methods (spectrography, waveform analysis) used in this study, and supported by strobe light laryngoscopy. This conclusion is important because of the extremely high incidences of varying degrees of hoarseness reported in recent studies of Parkinson disease.

25-hydroxycholecalciferol 1 alpha-hydroxylase activity in the kidney of the fetal, neonatal and adult guinea pig.

Homogenates of fetal, newborn and maternal kidney and placenta have been compared with homogenates of non-pregnant adult kidney for their ability to hydroxylate 25-hydroxycholecalciferol. The activity in the fetal kidney near term is similar to that in the mother and 4--5 times that in the non-pregnant adult. These differences from the non-pregnant adult are significant (p less than 0.05 and 0.1 fetus and newborn, respectively). Even higher levels are present in some newborn 12--24 h after birth, but these values fall towards the non-pregnant level in the following 21 days. Significant hydroxylating activity is present in the near-term placenta.

The supply of citrate to the sheep fetus.

In situ placental perfusion has been used to study the role of the sheep placenta in fetal citrate metabolism. The perfusate citrate concentrations rose steadily to values higher than in fetal plasma. This rise was not influenced by intravenous administration of citrate to the ewe. Concentration and electropotential gradients indicate that transplacental passage is unlikely and the rise is probably due to placental synthesis. However, the quantity of citrate supplied to the fetus was calculated to be small compared with the fetal metabolic rate. Comparison with the guinea pig shows close similarity in fetal plasma concentrations and the amount of citrate formed per unit weight of fetus.

Technique for in situ perfusion of the guinea pig placenta.

A simple technique is described for perfusing the guinea pig placenta in situ through the umbilical circulation. Flow rates, perfusion pressures, and transplacental electrical potential gradients were maintained for the duration of the perfusions (1--2h) at values reported for the exteriorised fetus. Terminally, the placentae were shown to be uniformly perfused and of normal weight.

A study of the permeability of the guinea pig placenta to citrate using recirculating placental perfusion technique.

The role of the guinea pig placenta in fetal citrate metabolism has been studied by perfusing the placenta in situ. The initial citrate concentrations in the perfusate plasma were lower than in the maternal plasma but rose progressively until, in some cases, they exceeded those in the mother. The rise was uninfluenced by intravenous administration of citrate to the mother. Citrate therefore does not enter the perfusate by simple diffusion from the maternal compartment. It may be synthesised within the placenta. From the rate of accumulation of citrate in the perfusate, the supply to the fetus was calculated to be small compared to the fetal metabolic rate. Citrate added to the perfusate became distributed in a space similar to the extracellular space and no change occurred in maternal citrate concentrations. Thus, the placenta does not appear to metabolise citrate or allow transport to the mother.