Properties of input-output Hammerstein-bilinear structure with application to an industrial air handling unit

When developing mathematical models, especially for control, the practical interest lies in relatively simple extensions of linear structures that offer improved modelling capabilities. In this paper a discrete-time input-output Hammerstein-bilinear structure is introduced and its properties are discussed in detail. It consists of a cascade connection of a static nonlinearity followed by a dynamic bilinear system. By combining advantages of constituent subsystems the Hammerstein-bilinear structure allows for both an input dependant dynamic behaviour (particular property of bilinear systems) and an increased flexibility of the steady-state characteristic (particular property of Hammerstein models) to be obtained simultaneously. Modelling capabilities of such structure are evaluated on an air-handling unit that is a part of an industrial heating, ventilation and air-conditioning system

Bond graph modelling of chemoelectrical energy transduction

Energy-based bond graph modelling of biomolecular systems is extended to include chemoelectrical transduction thus enabling integrated thermodynamically-compliant modelling of chemoelectrical systems in general and excitable membranes in particular. Our general approach is illustrated by recreating a well-known model of an excitable membrane. This model is used to investigate the energy consumed during a membrane action potential thus contributing to the current debate on the trade-off between the speed of an action potential event and energy consumption. The influx of Na+ is often taken as a proxy for energy consumption; in contrast, this paper presents an energy based model of action potentials. As the energy based approach avoids the assumptions underlying the proxy approach it can be directly used to compute energy consumption in both healthy and diseased neurons. These results are illustrated by comparing the energy consumption of healthy and degenerative retinal ganglion cells using both simulated and in vitro data

Enrollment Decision-Making by Students in Forestry and Related Natural Resource Degree Programmes Globally

A survey of 396 undergraduate and graduate students from 51 countries on 5 continents currently enrolled in Forestry or Related Natural Resource (FRNR) degree programmes was conducted of attendees to the International Union of Forest Research Organizations\u27 (IUFRO) conference in Salt Lake City, Utah, 2014. These perspectives come from some of the most active students in their respective fields. We explored the motivating reasons for enrolling in their current FRNR programme, and conversely why they may have been hesitant to do so. Results indicate that enjoyment of nature was the most important factor on average driving the decision to enroll, closely followed by job satisfaction, concern for the environment, enjoyment of outdoor recreation, being outdoors, and an interest in subject material. Hesitancy factors included earning potential, availability of funding/scholarships, and politically contentious issues. A number of significant differences were found across demographic categories. Of particular note was the greater hesitancy on the part of women and people of color to enroll in FRNR degree programmes compared to their white male counterparts. We discuss the limitations of our study arising from its international scope and imbalance of responses among countries and regions. HIGHLIGHTS Forestry and Related Natural Resources (FRNR) students from 51 countries report that enjoyment of nature was the most important factor driving their decision to enroll. Decision factors that caused hesitation included earning potential, availability of funding, and political issues. Importance factors differed significantly between genders, race/ethnicity, academic standing, world region, and social background (i.e. urban vs rural). Women and people of color from multiple world regions had a greater hesitancy to enroll in an FRNR programme than their white male counterparts. Implications for recruitment and retention include the need for continual diversity and inclusion efforts and a balance between personal preferences and employability

A Slow Axon Antidromic Blockade Hypothesis for Tremor Reduction via Deep Brain Stimulation

Parkinsonian and essential tremor can often be effectively treated by deep brain stimulation. We propose a novel explanation for the mechanism by which this technique ameliorates tremor: a reduction of the delay in the relevant motor control loops via preferential antidromic blockade of slow axons. The antidromic blockade is preferential because the pulses more rapidly clear fast axons, and the distribution of axonal diameters, and therefore velocities, in the involved tracts, is sufficiently long-tailed to make this effect quite significant. The preferential blockade of slow axons, combined with gain adaptation, results in a reduction of the mean delay in the motor control loop, which serves to stabilize the feedback system, thus ameliorating tremor. This theory, without any tuning, accounts for several previously perplexing phenomena, and makes a variety of novel predictions

Re-visiting Meltsner: Policy Advice Systems and the Multi-Dimensional Nature of Professional Policy Analysis

10.2139/ssrn.15462511-2

Computerised interpretation of fetal heart rate during labour (INFANT) : a randomised controlled trial

Background: Continuous electronic fetal heart-rate monitoring is widely used during labour, and computerised interpretation could increase its usefulness. We aimed to establish whether the addition of decision-support software to assist in the interpretation of cardiotocographs affected the number of poor neonatal outcomes. Methods: In this unmasked randomised controlled trial, we recruited women in labour aged 16 years or older having continuous electronic fetal monitoring, with a singleton or twin pregnancy, and at 35 weeks' gestation or more at 24 maternity units in the UK and Ireland. They were randomly assigned (1:1) to decision support with the INFANT system or no decision support via a computer-generated stratified block randomisation schedule. The primary outcomes were poor neonatal outcome (intrapartum stillbirth or early neonatal death excluding lethal congenital anomalies, or neonatal encephalopathy, admission to the neonatal unit within 24 h for >= 48 h with evidence of feeding difficulties, respiratory illness, or encephalopathy with evidence of compromise at birth), and developmental assessment at age 2 years in a subset of surviving children. Analyses were done by intention to treat. This trial is completed and is registered with the ISRCTN Registry, number 98680152. Findings: Between Jan 6, 2010, and Aug 31, 2013, 47 062 women were randomly assigned (23 515 in the decision-support group and 23 547 in the no-decision-support group) and 46 042 were analysed (22 987 in the decision-support group and 23 055 in the no-decision-support group). We noted no difference in the incidence of poor neonatal outcome between the groups-172 (0.7%) babies in the decision-support group compared with 171 (0.7%) babies in the no-decision-support group (adjusted risk ratio 1.01, 95% CI 0.82-1.25). At 2 years, no significant differences were noted in terms of developmental assessment. Interpretation: Use of computerised interpretation of cardiotocographs in women who have continuous electronic fetal monitoring in labour does not improve clinical outcomes for mothers or babies

Antibody in breastmilk following Pertussis vaccination in three-time windows in pregnancy

Background: Pertussis-containing vaccines are routinely offered in the UK at 16-32 weeks of gestation and have been shown to be safe and effective, but there remains debate about the best timing for vaccination. Most research into this has focused on serologic immunity, but breastmilk is also important in infant immunity, and the amount of IgA in breastmilk may impact mucosal immunity. It is important to understand if the timing of vaccination in pregnancy affects the concentration of IgA in breastmilk. Methods: Participants recruited as part of the MAMA (Maternal Antibody in Milk After Vaccination) and OpTIMUM (Optimizing the Timing of Whooping Cough Immunisations in Mums) trials received a pertussis-containing vaccine during pregnancy, either before 24 weeks, between 24 and 27+6 weeks or between 28 and 31+6 weeks. Samples of colostrum within 24 hours of delivery and breastmilk at 14 days were collected. Pertussis toxin, pertactin, tetanus toxoid and diphtheria toxoid specific-IgA levels were measured using a multiplex immunoassay. Results: There was no difference in specific IgA levels against pertussis toxin, pertactin, tetanus toxoid and diphtheria toxoid between the groups vaccinated within different time periods. For all antigens, there was decay in antigen-specific IgA levels between colostrum and breastmilk at 14 days. Conclusion: Our results suggest that the timing of administration of a pertussis-containing vaccine in pregnancy does not impact on antigen-specific IgA concentration in colostrum or breastmilk at 14 days

Parkinson’s disease mouse models in translational research

Animal models with high predictive power are a prerequisite for translational research. The closer the similarity of a model to Parkinson’s disease (PD), the higher is the predictive value for clinical trials. An ideal PD model should present behavioral signs and pathology that resemble the human disease. The increasing understanding of PD stratification and etiology, however, complicates the choice of adequate animal models for preclinical studies. An ultimate mouse model, relevant to address all PD-related questions, is yet to be developed. However, many of the existing models are useful in answering specific questions. An appropriate model should be chosen after considering both the context of the research and the model properties. This review addresses the validity, strengths, and limitations of current PD mouse models for translational research