A search for factors controlling the formation and maintenance of connections between the thelamus and cortex in vitro

Although the development of the nervous system is continuous, the neurones that constitute the nervous system proceed through specific developmental stages. Such stages included: birth, differentiation, migration, the formation of efferent and afferent connections, and the organisation of these connections based on exogenous and endogenous cues. Alternatively, a neuron may undergo "natural occurring" cell death at various points during development.When considering the complexity of the nervous system, it is not surprising that our knowledge, as to the factors that control these development stages, is limited One significant obstacle for experimentally addressing these questions, for practical and/or ethical reasons, has been the animal itself. Thus, the advent of tissue culture techniques has greatly facilitated research in this area.In addition to in vivo Dil tract-tracing experiments, I have used three different in vitro techniques: (i) co-cultures of organotypic explants on a two-dimensional collagen substrate, (ii) organotypic explants co-cultured within a three-dimensional collagen gel, and (iii) co-cultures of dissociated cells. Because serum is known to contain many trophic factors, only serum-free medium was used for all of these experiments. Using the above in vitro techniques, I investigated questions concerning the development of connections between the thalamus and cortex.These experiments yielded the following results, (i) When thalamocortical and corticothalamic efferent fibres began to grow in vivo at embryonic day 15 (El5), conserved diffusible target-derived factors enhanced their neurite elongation in vitro, (ii) The survival of El 5 thalamic and cortical neurones was independent from target-derived iii trophic support, since both the thalamus and cortex promoted their own survival in vitro. possibly through the production of endogenous trophic factors. However (iii), between E17 and postnatal day 2, a time coincident with the arrival of their fibres to their target, the survival of thalamocortical and corticothalamic neurones was dependent on factors released from their target, (iv) The production of growth promoting factors within the cortex increased with postnatal age and was at least partially regulated by afferent activity. And finally (v), it seems that the recognition/stop-signalling molecules expressed within these targets are also highly conserved since they were recognised in inter-species co-culture experiments. Thus, in general, the development of both thalamocortical and corticothalamic efferents are highly influenced by factors produced by their target cells in vitro. In vivo, these factors may play various roles during the different developmental stages from promoting neurite outgrowth and cell survival, to regulating the reorganisation of connection

Congenital cardiac surgery and parental perception of risk: a qualitative study

Introduction: The way risk is interpreted by parents of children undergoing congenital cardiac surgery is poorly documented. Literature suggests clinicians have concerns that parents may not understand the complexity of procedures. Conversely, some parents perceive an unnecessary over-emphasise of risks. Aim: To explore how risk is encountered by parents of children who are undergoing cardiac surgery, in order to deliver effective and compassionate care. Methods: A qualitative approach was adopted. Interviews were undertaken with eighteen parents (mothers n=10 fathers n=8). Recordings were transcribed verbatim and analyzed using a constant comparative based approach. Findings: Three themes emerged from the data: the nature of risk, reflecting the complexity of parental perception of risk and the influence of the doctor-parent relationship; presenting risk, highlighting the way in which risk is presented to and interpreted by parents; and risk and responsibility, examining the way in which parents engaged with risk and the impact of this on their relationship. Conclusions: The way in which risk is perceived by parents is complex and multifactorial. The doctor-parent relationship is key to parental engagement. However, parents manage risk and uncertainty through a number of mechanisms, including those perceived as being not rational. This can cause tension, particularly when required to engage in informed decision-making

GEOMATICS FOR SMART CITIES: OBTAINING THE URBAN PLANNING BAF INDEX FROM EXISTING DIGITAL MAPS

The urban analytics expression is spreading out. To our understanding, it deals with the capability of measuring cities and their communities, as a support to their effective planning and management. In other words, being an analytically well-known city is a precondition for pursuing smartness. Urban planning is a very important item for city management and is interrelated with many layers, including urban environmental quality, air quality and well-being. Effective urban planning is based on the knowledge of quantitative parameters such as the biotope area factor (BAF), which was originally proposed for the city of Berlin and is currently used in other cities. The BAF index is used to evaluate the degree of soil permeability and measures, to a certain extent and from a specific point of view, how a city is eco-friendly. The usual way of evaluating the BAF is based on the manual construction of dedicated maps, using existing orthophotos and oblique imagery as a support. But this method is expensive, time-consuming and non-objective, as it is prone to different interpretations. The paper presents a newly-developed methodology for calculating the BAF. It is based on the use of existing digital cartography and on the application of geoprocessing techniques from GIS science: it is therefore fully automated and objective. The Pavia city (Northern Italy) is used as a testsite and a careful validation of the developed methodology is carried out, by comparison to 12 manually surveyed test areas, corresponding to 5% of the built-up areas of the municipality

What Are Lightness Illusions and Why Do We See Them?

Lightness illusions are fundamental to human perception, and yet why we see them is still the focus of much research. Here we address the question by modelling not human physiology or perception directly as is typically the case but our natural visual world and the need for robust behaviour. Artificial neural networks were trained to predict the reflectance of surfaces in a synthetic ecology consisting of 3-D “dead-leaves” scenes under non-uniform illumination. The networks learned to solve this task accurately and robustly given only ambiguous sense data. In addition—and as a direct consequence of their experience—the networks also made systematic “errors” in their behaviour commensurate with human illusions, which includes brightness contrast and assimilation—although assimilation (specifically White's illusion) only emerged when the virtual ecology included 3-D, as opposed to 2-D scenes. Subtle variations in these illusions, also found in human perception, were observed, such as the asymmetry of brightness contrast. These data suggest that “illusions” arise in humans because (i) natural stimuli are ambiguous, and (ii) this ambiguity is resolved empirically by encoding the statistical relationship between images and scenes in past visual experience. Since resolving stimulus ambiguity is a challenge faced by all visual systems, a corollary of these findings is that human illusions must be experienced by all visual animals regardless of their particular neural machinery. The data also provide a more formal definition of illusion: the condition in which the true source of a stimulus differs from what is its most likely (and thus perceived) source. As such, illusions are not fundamentally different from non-illusory percepts, all being direct manifestations of the statistical relationship between images and scenes

Framing the ultimatum game: the contribution of simulation

It has now become widely accepted that economic decisions are influenced by cognitive and emotional processes. In the present study, we aimed at disentangling the neural mechanisms associated with the way in which the information is formulated, i.e., framing effect, in terms of gain or loss, which influences people\u2019s decisions. Participants played a fMRI version of the Ultimatum Game (UG) where we manipulated bids through two different frames: the expression \u201cI give you\u201d (gain) focusing on money the respondent would receive if she/he agreed with the proponent, and the expression \u201cI take\u201d (loss) focusing on the money that would be removed from the respondent in the event that she/he accepted the offer. Neuroimaging data revealed a frame by response interaction, showing an increase of neural activity in the right rolandic operculum/insular cortex, the anterior cingulate, among other regions, for accepting the frame \u201cI take\u201d vs. rejecting, as compared to accepting the frame \u201cI give you\u201d vs. rejecting. In addition, the left occipito-temporal junction was activated for \u201cI take\u201d vs. \u201cI give you\u201d for offer 5, corresponding to the equal offer made unpleasant by the presence of the frame \u201cI take,\u201d where is the proposer that takes the money. Our data extend the current understanding of the neural substrates of social decision making, by disentangling the structures sensitive to the way in which the information is formulated (i.e., framing effect), in terms of gain or loss

Clinical decision making in paramedic practice. A qualitative study exploring the challenges of responding to mental health needs.

The paramedic service responds to emergency calls for a variety of reasons with many relating to mental health concerns. This qualitative study aims to explore the views and experiences of student paramedics in relation to clinical decision making for mental health calls. Focus groups were utilised to investigate the participants’ perspectives. Thematic analysis was used to organise data and identify key issues. Findings suggested some disparity between what paramedic students were prepared for and the reality of public need. Clinical decision-making in relation to those with mental health problems was significantly influenced by the current provision of mental health services and the lack of mental health specific education for student paramedics. Current changes to the paramedic programme make this an opportune time for a review of curriculum content

VSD exposure by tricuspid valve chordal detachment - a retrospective matched study

Background: Transatrial approach is the standard method in repairing ventricular septal defect in pediatric population. However, tricuspid valve (TV) apparatus might obscure the inferior border of the VSD risking the adequacy of repair by leaving residual VSD or heart block. Detachment of the TV chordae has been described as an alternative technique to TV leaflet detachment. Aim of this study is to investigate the safeness of such technique. Methods: Retrospective review of patients who underwent VSD repair between 2015 and 2018. Group A (n=25) had VSD repair with TV chordae detachment were matched for age and weight to group B (n=25) without tricuspid chordal or leaflet detachment. ECG and echocardiogram at discharge and at 3 years of follow-up were reviewed to identify new ECG changes, residual VSD and TV regurgitation. Results: Median age in group A and B were 6.13 (IQR 4.33-7.91) and 6.33 (4.77- 7.2) months. New onset right bundle branch block (RBBB) was diagnosed at discharge in 28% (n=7) of group A versus 56% (n=14) in group B (p= 0.044), while the incidence dropped to 16% (n=4) in group A versus 40% (n=10) in group B (p= 0.059) in the 3 years follow-up ECG. Echocardiogram at discharge showed moderate tricuspid regurgitation in 16% (n=4) in group A and 12% (n=3) in group B (p=0.867). 3 years follow-up echocardiography revealed no moderate or severe tricuspid regurgitation and no significant residual VSD in either group. Conclusion: No significant difference in operative time was observed between the 23 two techniques. TV chordal detachment technique reduces the incidence of 24 postoperative RBBB without increasing the incidence of TV regurgitation at discharge

Grid services for the MAGIC experiment

Exploring signals from the outer space has become an observational science under fast expansion. On the basis of its advanced technology the MAGIC telescope is the natural building block for the first large scale ground based high energy gamma-ray observatory. The low energy threshold for gamma-rays together with different background sources leads to a considerable amount of data. The analysis will be done in different institutes spread over Europe. Therefore MAGIC offers the opportunity to use the Grid technology to setup a distributed computational and data intensive analysis system with the nowadays available technology. Benefits of Grid computing for the MAGIC telescope are presented.Comment: 5 pages, 1 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200

Congenital Cardiac Surgery and Parental Perception of Risk: A Quantitative Analysis

Introduction: Interpretation of risk by parents of children undergoing congenital cardiac surgery is poorly documented. The available evidence highlights a dichotomy, where clinicians suggest parents may not grasp the complexity and risk associated with procedures, whilst some parents suggest risk is unnecessarily over-emphasised. Aim: To quantify how risk is perceived by parents Methods: 106 parents of children undergoing cardiac surgery were recruited and completed a Likert scale from 1 (perceived low-risk) to 6 (perceived high-risk), at five points: arrival at pre-admission; post discussion with anaethetist/surgeon; day of surgery; discharge from intensive care; at outpatient follow up. The surgical sample was stratified according to risk adjustment in congenital heart surgery. Analysis: Data was analysed using Wilcoxon rank tests for differences in distributions of scores, and Krippendorff's Alpha to examine level of agreement. Results: Median parental risk scores varied over time, with no consistent risk scores observed. Maternal scores were consistently higher than paternal scores at every time point (p<0.001). Postoperative complications resulted in a persistent rise in risk perception at follow up (p<0.001). Analysis of parental risk scores, and objective measures of surgical risk highlighted poor agreement that was particularly marked at the extremes of risk. Conclusions: Parents perceived higher risk scores than those reported by the clinical team. Mothers reported statistically significant higher scores than their partners, highlighting potential tensions. In addition, the changing perception of risk over time emphasizes the need for flexible levels of support and information as parents navigate uncertainty

GEOMATICS FOR SMART CITIES: OBTAINING THE URBAN PLANNING BAF INDEX FROM EXISTING DIGITAL MAPS

The urban analytics expression is spreading out. To our understanding, it deals with the capability of measuring cities and their communities, as a support to their effective planning and management. In other words, being an analytically well-known city is a precondition for pursuing smartness. Urban planning is a very important item for city management and is interrelated with many layers, including urban environmental quality, air quality and well-being. Effective urban planning is based on the knowledge of quantitative parameters such as the biotope area factor (BAF), which was originally proposed for the city of Berlin and is currently used in other cities. The BAF index is used to evaluate the degree of soil permeability and measures, to a certain extent and from a specific point of view, how a city is eco-friendly. The usual way of evaluating the BAF is based on the manual construction of dedicated maps, using existing orthophotos and oblique imagery as a support. But this method is expensive, time-consuming and non-objective, as it is prone to different interpretations. The paper presents a newly-developed methodology for calculating the BAF. It is based on the use of existing digital cartography and on the application of geoprocessing techniques from GIS science: it is therefore fully automated and objective. The Pavia city (Northern Italy) is used as a testsite and a careful validation of the developed methodology is carried out, by comparison to 12 manually surveyed test areas, corresponding to 5% of the built-up areas of the municipality