Evolution of spiral and scroll waves of excitation in a mathematical model of ischaemic border zone

Abnormal electrical activity from the boundaries of ischemic cardiac tissue is recognized as one of the major causes in generation of ischemia-reperfusion arrhythmias. Here we present theoretical analysis of the waves of electrical activity that can rise on the boundary of cardiac cell network upon its recovery from ischaemia-like conditions. The main factors included in our analysis are macroscopic gradients of the cell-to-cell coupling and cell excitability and microscopic heterogeneity of individual cells. The interplay between these factors allows one to explain how spirals form, drift together with the moving boundary, get transiently pinned to local inhomogeneities, and finally penetrate into the bulk of the well-coupled tissue where they reach macroscopic scale. The asymptotic theory of the drift of spiral and scroll waves based on response functions provides explanation of the drifts involved in this mechanism, with the exception of effects due to the discreteness of cardiac tissue. In particular, this asymptotic theory allows an extrapolation of 2D events into 3D, which has shown that cells within the border zone can give rise to 3D analogues of spirals, the scroll waves. When and if such scroll waves escape into a better coupled tissue, they are likely to collapse due to the positive filament tension. However, our simulations have shown that such collapse of newly generated scrolls is not inevitable and that under certain conditions filament tension becomes negative, leading to scroll filaments to expand and multiply leading to a fibrillation-like state within small areas of cardiac tissue.Comment: 26 pages, 13 figures, appendix and 2 movies, as accepted to PLoS ONE 2011/08/0

A Comparison of the Effects of Child Management and Planned Activities Training in Five Parenting Environments

This study compared the effects of two procedures designed to enhance the extra training effects of behavioral parent training. Twenty parents of oppositional children were randomly assigned to either a child management training condition or a combined child management plus planned activities condition. A further 10 non-problem children and their parents served as a social validation group. Observations of both parent and child behavior were conducted in each of five home observation settings (breakfast time, kindy (kindergarten) or school exit, a structured playtime, bathtime, and bedtime). Both training procedures resulted in changes in both child oppositional and parent aversive behavior in all observation settings. In addition, desired positive parenting behaviors also improved in all settings. Treatment effects were maintained in all settings at 3-month follow-up. Comparisons between oppositional children following treatment and children in the social validation group showed that they each displayed similarly low levels of oppositional behavior in all settings. The implications of the results for facilitating generalized changes in behavioral parent training are discussed

Supporting parents of youths with intellectual disabilities and psychopathology

Background: Parents of children and adolescents with both intellectual disabilities (ID) and psychopathology often experience high levels of parenting stress. To support these parents, information is required regarding the types of support they need and whether their needs are met. Method: In a sample of 745 youths (aged 10-24 years) with moderate to borderline ID, 289 parents perceived emotional and/or behavioural problems in their child. They were asked about their needs for support and whether these needs were met. Logistic regression analysis revealed the variables associated with both needing and receiving specific types of support. In addition, we asked those parents who had refrained from seeking support about their reasons. Results: Most parents (88.2%) needed some supports, especially a friendly ear, respite care, child mental health care and information. Parents who perceived both emotional and behavioural problems in their child needed support the most. In addition, parents whose child had any of these problems before the past year, who worried most about their child and suffered from psychopathology themselves, more often needed support. Parents of children with moderate ID or physical problems especially needed 'relief care', that is, respite care, activities for the child and practical/material help. The need for a friendly ear was met most often (75.3%), whereas the need for parental counselling was met least often (35.5%). Not receiving support despite having a need for it was primarily related to the level of need. Parents who indicated to have a stronger need for support received support more often than parents who had a relatively low need for support. The parents' main reasons for not seeking support concerned their evaluation of their child's problems (not so serious or temporary), not knowing where to find support or wanting to solve the problems themselves first. Conclusions: Most parents had various support needs that were frequently unmet. Service providers should especially aim at providing information, activities, child mental health care and parental counselling. Furthermore, parents need to be informed about where and how they can obtain what kind of support. A case manager can be of help in this

Social work students as community partners in a family intervention programme

Summary: This paper describes the findings from the evaluation of a UK initiative which engaged social work students as community partners within an educational based family intervention programme. Fourteen social work students in the first year of a BA (Hons) were placed in the programme to meet the volunteering requirements of their 'Community Project'. By engaging with the community-based family programme at an early stage in their education, students experienced the benefits of interventions, focussing on sustainability, citizenship and parent participation. We describe the approach and discuss the evaluation outcomes to illustrate the potential of utilising co-learning with families in social work education. In taking up the role of community partners, students observed first-hand the value of incorporating horizontal relationships into their learning and experienced direct knowledge exchange with service users at an early stage in their training. Findings: The findings suggest that this experience enabled students to connect with conceptualisations of macro alongside micro practice in their professional development as social workers. Further, connecting critical social theories with the direct experience of families promoted the learners own empowerment and conscientization. Application: This provided a means of embedding social work values and aspirations towards social justice in their future practice orientation

Controlling magnetic anisotropy in La_0.7Sr_0.3MnO₃ nanostructures

We have developed a chlorine based dry etching process for nanopatterning the ferromagnetic oxide La<sub>0.7</sub>Sr<sub>0.3</sub>MnO<sub>3</sub> (LSMO). Large arrays of millions of identical structures have been fabricated from thin LSMO films by electron-beam lithography and reactive ion etching. SQUID magnetometry demonstrates that patterned nanostructures with lateral dimensions down to 100 nm retain their full magnetization and the Curie temperature of the bulk layer. In addition, their shape anisotropy is sufficient to overcome the crystalline anisotropy of the bulk. High resolution scanning transmission electron microscopy shows that crystallinity is preserved even at the edges of the nanostructures

Reperfusion therapy for ST elevation acute myocardial infarction 2010/2011: current status in 37 ESC countries

Aims Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion therapy in ST-elevation myocardial infarction (STEMI). We conducted this study to evaluate the contemporary status on the use and type of reperfusion therapy in patients admitted with STEMI in the European Society of Cardiology (ESC) member countries. Methods and results A cross-sectional descriptive study based on aggregated country-level data on the use of reperfusion therapy in patients admitted with STEMI during 2010 or 2011. Thirty-seven ESC countries were able to provide data from existing national or regional registries. In countries where no such registries exist, data were based on best expert estimates. Data were collected on the use of STEMI reperfusion treatment and mortality, the numbers of cardiologists, and the availability of PPCI facilities in each country. Our survey provides a brief data summary of the degree of variation in reperfusion therapy across Europe. The number of PPCI procedures varied between countries, ranging from 23 to 884 per million inhabitants. Primary percutaneous coronary intervention and thrombolysis were the dominant reperfusion strategy in 33 and 4 countries, respectively. The mean population served by a single PPCI centre with a 24-h service 7 days a week ranged from 31 300 inhabitants per centre to 6 533 000 inhabitants per centre. Twenty-seven of the total 37 countries participated in a former survey from 2007, and major increases in PPCI utilization were observed in 13 of these countries. Conclusion Large variations in reperfusion treatment are still present across Europe. Countries in Eastern and Southern Europe reported that a substantial number of STEMI patients are not receiving any reperfusion therapy. Implementation of the best reperfusion therapy as recommended in the guidelines should be encourage

Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life

Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PALand PPOpathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future

Public Library-Based Social Work Field Placements: Guidance for Public Libraries Planning to Become a Social Work Practicum Site

Public libraries are increasingly faced with patron psychosocial needs, including mental health problems, substance use, homelessness, or poverty-related needs. Since library staff are often not trained to address these needs, many are choosing to host on-site social work practicum students to provide information and referrals for patrons presenting with psychosocial needs. However, little existing guidance is available about initiating a social work practicum placement, which can leave libraries unprepared and often “reinventing the wheel”. This manuscript provides guidance on the steps that should be considered by libraries intending to host their first social work practicum student

Probing the Roughness of Porphyrin Thin Films with X-ray Photoelectron Spectroscopy

Thin-film growth of molecular systems is of interest for many applications, such as for instance organic electronics. In this study, we demonstrate how X-ray photoelectron spectroscopy (XPS) can be used to study the growth behavior of such molecular systems. In XPS, coverages are often calculated assuming a uniform thickness across a surface. This results in an error for rough films, and the magnitude of this error depends on the kinetic energy of the photoelectrons analyzed. We have used this kinetic-energy dependency to estimate the roughnesses of thin porphyrin films grown on rutile TiO2(110). We used two different molecules: cobalt (II) monocarboxyphenyl-10,15,20-triphenylporphyrin (CoMCTPP), with carboxylic-acid anchor groups, and cobalt (II) tetraphenylporphyrin (CoTPP), without anchor groups. We find CoMCTPP to grow as rough films at room temperature across the studied coverage range, whereas for CoTPP the first two layers remain smooth and even; depositing additional CoTPP results in rough films. Although, XPS is not a common technique for measuring roughness, it is fast and provides information of both roughness and thickness in one measurement.Fil: Kataev, Elmar. Universitat Erlangen-Nuremberg; AlemaniaFil: Wechsler, Daniel. Universitat Erlangen-Nuremberg; AlemaniaFil: Williams, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; ArgentinaFil: Köbl, Julia. Universitat Erlangen-Nuremberg; AlemaniaFil: Tsud, Natalia. Karlova Univerzita (cuni); República ChecaFil: Franchi, Stefano. Istituto di Struttura della Materia; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Steinruck, Hans Peter. Universitat Erlangen-Nuremberg; AlemaniaFil: Lytken, Ole. Universitat Erlangen-Nuremberg; Alemani