Signatures of four-particle correlations associated with exciton-carrier interactions in coherent spectroscopy on bulk GaAs

Transient four-wave mixing studies of bulk GaAs under conditions of broad bandwidth excitation of primarily interband transitions have enabled four-particle correlations tied to degenerate (exciton-exciton) and nondegenerate (exciton-carrier) interactions to be studied. Real two-dimensional Fourier-transform spectroscopy (2DFTS) spectra reveal a complex response at the heavy-hole exciton emission energy that varies with the absorption energy, ranging from dispersive on the diagonal, through absorptive for low-energy interband transitions to dispersive with the opposite sign for interband transitions high above band gap. Simulations using a multilevel model augmented by many-body effects provide excellent agreement with the 2DFTS experiments and indicate that excitation-induced dephasing (EID) and excitation-induced shift (EIS) affect degenerate and nondegenerate interactions equivalently, with stronger exciton-carrier coupling relative to exciton-exciton coupling by approximately an order of magnitude. These simulations also indicate that EID effects are three times stronger than EIS in contributing to the coherent response of the semiconductor

The rural mother's experience of caring for a child with a chronic health condition: An integrative review

© 2018 John Wiley & Sons Ltd Aims and objectives: To identify and review the literature on rural mothers’ experiences in caring for a child with a chronic health condition. Background: Families living with a child who has a chronic health condition experience many challenges; these are often amplified for families living in rural areas, where issues such as the distance from services add further challenges the family must manage. Like many children, rural children with chronic health conditions are primarily cared for by their mothers. The additional strain of geography creates its own unique experiences for mothers who need to access the high-quality care that their child requires. Design: Integrative literature review using the Equator PRISMA guidelines. Methods: A search of databases; Cochrane, CINAHL, Ovid, PubMed, ProQuest Health and Medicine, Informit and Scopus for studies published between 2005–2016 using an integrative review approach. A total of 1,484 studies were identified with an additional six studies found through snowballing. The search resulted in seven studies being meeting the inclusion criteria after using the Critical Appraisal Skills Programme. Results: Data from the seven articles were analysed, and the mothers’ experiences were synthesised into five themes: “struggling for resources,” “barriers in accessing services,” “strain of decision-making,” “mother's physical and emotional breakdown” and “the daily management of family activities”. These five themes formed the basis of this article. Conclusions: The findings indicate that mothers from rural areas face additional barriers related to their rurality, including transportation difficulties, socioeconomic status and social isolation, and are challenged by limited access to specialty medical services, educators and allied health professionals. The literature review outcome will assist in informing nursing practice through identifying and allocating resources to reduce these barriers; rural mother experience will assist in enabling the child to reach their full developmental potential. Relevance to clinical practice: There is a need for health professionals to understand the challenges and barriers rural mothers face in accessing services. Nurses can assist rural mothers to navigate and access the appropriate services in order to reduce health inequity, increase accessibility to services and reduce rural disadvantage for their child. Nurses and health professionals are in an ideal position to develop future models of care that optimise health outcomes and enable equity and access to services for rural children with chronic conditions similar to those experienced by their urban counterparts

Design of a Linear Time-Varying Cross-Coupled Iterative Learning Controller

In many manufacturing applications contour tracking is more important than individual axis tracking. Many control techniques, including iterative learning control (ILC), target individual axis error. Because individual axis error only indirectly relates to contour error, these approaches may not be very effective for contouring applications. Cross-coupled ILC (CCILC) is a variation on traditional ILC that targets the contour tracking directly. In contour trajectories with rapid changes, high frequency control is necessary in order to meet tracking requirements. This paper presents an improved CCILC that uses a linear time-varying (LTV) filter to provide high frequency control for short durations. The improved CCILC is designed for raster-scan tracking on a Cartesian robotic test platform. Analysis and experimental results are presented

Help Seeking and Access to Primary Care for People from “Hard-to-Reach” Groups with Common Mental Health Problems

Background. In the UK, most people with mental health problems are managed in primary care. However, many individuals in need of help are not able to access care, either because it is not available, or because the individual's interaction with care-givers deters or diverts help-seeking. Aims. To understand the experience of seeking care for distress from the perspective of potential patients from “hard-to-reach” groups. Methods. A qualitative study using semi-structured interviews, analysed using a thematic framework. Results. Access to primary care is problematic in four main areas: how distress is conceptualised by individuals, the decision to seek help, barriers to help-seeking, and navigating and negotiating services. Conclusion. There are complex reasons why people from “hard-to-reach” groups may not conceptualise their distress as a biomedical problem. In addition, there are particular barriers to accessing primary care when distress is recognised by the person and help-seeking is attempted. We suggest how primary care could be more accessible to people from “hard-to-reach” groups including the need to offer a flexible, non-biomedical response to distress

Crop Residue Effects on Surface Radiation and Energy Balance - Review

Crop residues alter the surface properties of soils. Both shortwave albedo and longwave emissivity are affected. These are linked to an effect of residue on surface evaporation and water content. Water content influences soil physical properties and surface energy partitioning. In summary, crop residue acts to soil as clothing acts to skin. Compared to bare soil, crop residues can reduce extremes of heat and mass fluxes at the soil surface. Managing crop residues can result in more favorable agronomic soil conditions. This paper reviews research results of the quantity, quality, architecture, and surface distribution of crop residues on soil surface radiation and energy balances, soil water content, and soil temperature

Being an Early-Career CMS Academic in the Context of Insecurity and ‘Excellence’: The Dialectics of Resistance and Compliance

Drawing on a dialectical approach to resistance, we conceptualise the latter as a multifaceted, pervasive and contradictory phenomenon. This enables us to examine the predicament in which early-career Critical Management Studies academics find themselves in the current times of academic insecurity and ‘excellence’, as gleaned through this group’s understandings of themselves as resisters and participants in the complex and contradictory forces constituting their field. We draw on 24 semi-structured interviews to map our participants’ accounts of themselves as resisters in terms of different approaches to tensions and contradictions between, on the one hand, the interviewees’ Critical Management Studies alignment and, on the other, the ethos of business school neoliberalism. Emerging from this analysis are three contingent and interlinked narratives of resistance and identity – diplomatic, combative and idealistic – each of which encapsulates a particular mode (negotiation, struggle, and laying one’s own path) of engaging with the relationship between Critical Management Studies and the business school ethos. The three narratives show how early-career Critical Management Studies academics not only use existing tensions, contradictions, overlaps and alliances between these positions to resist and comply with selected forces within each, but also contribute to the (re-)making of such overlaps, alliances, tensions and contradictions. Through this reworking of what it means to be both Critical Management Studies scholars and business school academics, we argue, early-career Critical Management Studies academics can be seen as active resisters and re-constituters of their complex field

Lidar technology measurements and technology: Report of panel

Lidar is ready to make an important contribution to tropospheric chemistry research with a variety of spaceborne measurements that complement the measurements from passive instruments. Lidar can now be considered for near-term and far-term space missions dealing with a number of scientifically important issues in tropospheric chemistry. The evolution in the lidar missions from space are addressed and details of these missions are given. The laser availability for space missions based upon the technical data is assessed

“Tales and Adventures”: G.A. Henty’s Union Jack and the Competitive World of Publishing for Boys in the 1880s’

In the competitive publishing environment of the late nineteenth century, writers and magazines had to distinguish themselves carefully from potential rivals. This article examines how G.A. Henty’s quality boys’ weekly, Union Jack (1880-83), attempted to secure a niche in the juvenile publishing market by deliberately distinguishing itself from other papers as a literary, imperialist and “healthy” publication. The article explores the design and marketing techniques of the magazine, its status as a fiction paper, the high calibre of its contributors, and its aggressive rhetoric in targeting an exclusively masculine audience. It argues that while Union Jack was marketed as a niche publication, it eventually failed to distinguish itself sufficiently to survive in an extremely competitive environment

Domestic groundwater abstraction in Lagos, Nigeria: a disjuncture in the Science-Policy-Practice Interface?

The rapid development of groundwater systems as part of urban water supplies around the globe is raising critical questions regarding the sustainable management of this essential resource. Yet, in many major cities, the absence of an effective policy regime means that the practice of groundwater exploitation is driven by the actions of domestic households and drilling contractors. Understanding what shapes the decisions and practices of these actors, their understandings of the groundwater resource and the extent to which scientific knowledge shapes this understanding, is an area of critical importance that is currently under-researched. Using a mixed-methods methodology, the paper explores domestic practices of groundwater abstraction in Lagos, Nigeria. It finds that there is a disjuncture between the households who are actively shaping exploitation of the groundwater resource on a day-to-day basis and science and state actors. This disjuncture results in household decisions that are influenced by commonly held, but potentially outdated, perceptions of the groundwater resource rather than scientific evidence or policy instruments. The unseen nature of groundwater resources effectively renders the scale of changing groundwater conditions invisible to households and the state, adding to the challenge of influencing practice. Addressing this disjuncture requires not just more scientific knowledge, but also the active construction of interfaces with, and between, non-state actors through which knowledge can be confronted, discussed and shared

Resilience in groundwater supply systems: integrating resource based approaches with agency, behaviour and choice

Access to safe and reliable water supplies is a key goal for households and governments across most of Africa. Groundwater reserves can play a critical role in achieving this, yet risks of contamination and over-abstraction threaten to undermine the resilience of this supply. A rapidly rising trend for privately-developed wells and boreholes raises additional concerns about the vulnerability of water supplies to natural or man-made environmental shocks. The potential scale of the situation is particularly marked in Nigeria where the use of boreholes has increased exponentially since 1999 (from 10% of the population to 38% in 2015), with most other forms of water supply, notably piped tap water, falling. Developing effective groundwater management approaches that build the resilience of communities is challenging, not least given the range of different actors involved, their competing interests and demands, and variations in the hydrogeological environment. Insights from resilience studies in social science emphasise how the resilience of ecological resources to shocks and change is critically linked to the adaptive capacity of social systems and their agents. Choices made now have long-lasting effects, yet these choices are little understood. Understanding the choices made by consumers, drillers and policy actors requires a strong interdisciplinary dimension and argues for new perspectives as to how the resilience of communities and societies might be built. The project brings together a unique interdisciplinary collaboration between academics from the UK and Nigeria working in the fields of economic geography, psychology, hydrogeology and journalism studies