Democratization in a passive dendritic tree : an analytical investigation

One way to achieve amplification of distal synaptic inputs on a dendritic tree is to scale the amplitude and/or duration of the synaptic conductance with its distance from the soma. This is an example of what is often referred to as “dendritic democracy”. Although well studied experimentally, to date this phenomenon has not been thoroughly explored from a mathematical perspective. In this paper we adopt a passive model of a dendritic tree with distributed excitatory synaptic conductances and analyze a number of key measures of democracy. In particular, via moment methods we derive laws for the transport, from synapse to soma, of strength, characteristic time, and dispersion. These laws lead immediately to synaptic scalings that overcome attenuation with distance. We follow this with a Neumann approximation of Green’s representation that readily produces the synaptic scaling that democratizes the peak somatic voltage response. Results are obtained for both idealized geometries and for the more realistic geometry of a rat CA1 pyramidal cell. For each measure of democratization we produce and contrast the synaptic scaling associated with treating the synapse as either a conductance change or a current injection. We find that our respective scalings agree up to a critical distance from the soma and we reveal how this critical distance decreases with decreasing branch radius

The impact of a pharmacist on post-take ward round prescribing and medication appropriateness

Background Medication communication and prescribing on the post-take ward round following patient admission to hospital can be suboptimal leading to worse patient outcomes. Objective To evaluate the impact of clinical pharmacist participation on the post-take ward round on the appropriateness of medication prescribing, medication communication, and overall patient health care outcomes. Setting Tertiary referral teaching hospital, Brisbane, Australia. Method A pre-post intervention study was undertaken that compared the addition of a senior clinical pharmacist attending the post-take ward was compared to usual wardbase pharmacist service, with no pharmacist present of the post-take ward round. We assessed the proportion of patients with an improvement in medication appropriateness from admission to discharge, using the START/STOPP checklists. Medication communication was assessed by the mean number of brief and in-depth discussions, with health care outcomes measured by comparing length of stay and 28-day readmission rates. Main outcome measures: Medication appropriateness according to the START/STOPP list, number and type of discussions with team members and length of stay and readmission rate. Results Two hundred and sixty patients were recruited (130 pre- and 130-post-intervention), across 23 and 20 post-take ward rounds, respectively. Post-intervention, there was increase in the proportion of patients who had an improvement medication appropriateness (pre-intervention 25.4%, post-intervention 36.9%; p = 0.004), the number of in-depth discussions about patients’ medication (1.9 ± 1.7 per patient pre-intervention, 2.7 ± 1.7 per patient post-, p < 0.001), and the number relating to high-risk medications (0.71 ± 1.1 per patient pre-intervention, to 1.2 ± 1.2 per patient post-, p < 0.05). Length of stay and 28-day mortality were unchanged. Conclusion Clinical pharmacist participation on the post-take ward round leads to improved medication-related communication and improved medication appropriateness but did not significantly improve health care outcomes

Robustness and Enhancement of Neural Synchronization by Activity-Dependent Coupling

We study the synchronization of two model neurons coupled through a synapse having an activity-dependent strength. Our synapse follows the rules of Spike-Timing Dependent Plasticity (STDP). We show that this plasticity of the coupling between neurons produces enlarged frequency locking zones and results in synchronization that is more rapid and much more robust against noise than classical synchronization arising from connections with constant strength. We also present a simple discrete map model that demonstrates the generality of the phenomenon.Comment: 4 pages, accepted for publication in PR

Awareness and knowledge of HPV and cervical cancer in female students: A survey (with a cautionary note)

We conducted a survey to explore levels of awareness and knowledge of human papillomavirus (HPV) and cervical cancer in 170 female students and whether mode of data collection (online vs. paper) affected the results. 27% of women named HPV as a cause of cervical cancer with online respondents more likely to do so. 75% of women had heard of HPV. More online respondents had heard of HPV than paper respondents. 127 women reported having heard of HPV, with a mean knowledge score of 2.989 (standard deviation [SD] 1.599). Online respondents scored higher (3.57, SD 1.316) than paper respondents (2.688, SD 1.591). Knowledge and awareness of HPV and its link to cervical cancer appear to have increased which may be related to the HPV vaccination programme. However, there is still a considerable number of women with little to no knowledge of HPV. Online surveys may result in an inflated estimation of awareness and knowledge