A general description of Loran-C: Present and potential applications

Loran-C is a low frequency (100 kHz) pulse navigation system. The pulse format and phase stability of the system are of paramount importance for both navigation and time synchronization using this system. Present Loran-C installations operated by the U. S. Coast Guard cover much of the northern hemisphere. A recent government-wide decision has declared that Loran-C will be the U. S. Coastal confluence navigation system for the immediate future. Therefore, Loran-C stations are presently being installed or planned to cover the entire U. S. coastline

Diagnosis and management of eosinophilic asthma: a US perspective.

Eosinophilic asthma is now recognized as an important subphenotype of asthma based on the pattern of inflammatory cellular infiltrate in the airway. Eosinophilic asthma can be associated with increased asthma severity, atopy, late-onset disease, and steroid refractoriness. Induced sputum cell count is the gold standard for identifying eosinophilic inflammation in asthma although several noninvasive biomarkers, including fractional exhaled nitric oxide and periostin, are emerging as potential surrogates. As novel therapies and biologic agents become increasingly available, there is an increased need for specific phenotype-directed treatment strategies. Greater recognition and understanding of the unique immunopathology of this asthma phenotype has important implications for management of the disease and the potential to improve patient outcomes. The present review provides a summary of the clinical features, pathogenesis, diagnosis, and management of eosinophilic asthma

Type 2 Innate Lymphoid Cells in Allergic Disease.

Type II innate lymphoid cells (ILC2) are a novel population of lineage-negative cells that produce high levels of Th2 cytokines IL-5 and IL-13. ILC2 are found in human respiratory and gastrointestinal tissue as well as in skin. Studies from mouse models of asthma and atopic dermatitis suggest a role for ILC2 in promoting allergic inflammation. The epithelial cytokines IL-25, IL-33, and TSLP, as well as the lipid mediator leukotriene D4, have been shown to potently activate ILC2 under specific conditions and supporting the notion that many separate pathways in allergic disease may result in stimulation of ILC2. Ongoing investigations are required to better characterize the relative contribution of ILC2 in allergic inflammation as well as mechanisms by which other cell types including conventional T cells regulate ILC2 survival, proliferation, and cytokine production. Importantly, therapeutic strategies to target ILC2 may reduce allergic inflammation in afflicted individuals. This review summarizes the development, surface marker profile, cytokine production, and upstream regulation of ILC2, and focuses on the role of ILC2 in common allergic diseases

Network Synthesis of Linear Dynamical Quantum Stochastic Systems

The purpose of this paper is to develop a synthesis theory for linear dynamical quantum stochastic systems that are encountered in linear quantum optics and in phenomenological models of linear quantum circuits. In particular, such a theory will enable the systematic realization of coherent/fully quantum linear stochastic controllers for quantum control, amongst other potential applications. We show how general linear dynamical quantum stochastic systems can be constructed by assembling an appropriate interconnection of one degree of freedom open quantum harmonic oscillators and, in the quantum optics setting, discuss how such a network of oscillators can be approximately synthesized or implemented in a systematic way from some linear and non-linear quantum optical elements. An example is also provided to illustrate the theory.Comment: Revised and corrected version, published in SIAM Journal on Control and Optimization, 200

Robust quantum parameter estimation: coherent magnetometry with feedback

We describe the formalism for optimally estimating and controlling both the state of a spin ensemble and a scalar magnetic field with information obtained from a continuous quantum limited measurement of the spin precession due to the field. The full quantum parameter estimation model is reduced to a simplified equivalent representation to which classical estimation and control theory is applied. We consider both the tracking of static and fluctuating fields in the transient and steady state regimes. By using feedback control, the field estimation can be made robust to uncertainty about the total spin number

Obesity and the Ageing Brain: Could Leptin Play a Role in Neurodegeneration?

Obesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer's disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer's disease suggesting that it may be an important research target in the quest for strategies to prevent, halt, or cure this condition

Niche Partitioning Among Arbuscular Mycorrhizal Fungi and Consequences for Host Plant Performance

We understand little about the factors that determine and maintain local species diversity of arbuscular mycorrhizal fungi (AMF), the reasons why a single plant has multiple AMF partners, and how that diversity influences host plant performance. The extent to which co-occurring AMF species occupy different niche space, based on their ability to tolerate different soil conditions or differentially promote host plant growth in those differing conditions, offers possible explanations for the maintenance of diversity. AMF community composition was examined in relation to soil variability in a naturally metalliferous serpentine grassland and along a Cu, Cd, Pb, and Zn soil contamination gradient. Both field surveys demonstrated that AMF community composition is strongly influenced by soil factors and provide evidence that local diversity of AMF communities is at least partially maintained by environmental niche partitioning among fungal species. Because there is some evidence that AMF species can be non-additive in their effects on plant growth, the appropriate measure of AMF function may be how much plant growth is affected when that particular AMF species is deleted from the community. Greenhouse experiments using this deletion approach, and the traditional approach of evaluating host plant growth with a single AMF species, were performed. The experiments involved two grass species: Andropogon gerardii and Sorhastrum nutans and a subset of their natural AMF community grown in soils differing in nitrogen, phosphorus, and nickel, which is naturally high in the plants\u27 native serpentine soils. This deletion method revealed that functional redundancy, with regards to host plant growth promotion, was the most common consequence of multiple species infecting one root. Functional complementarity and functional synergy, which may help explain why plants support multiple partners, were also demonstrated. Each of these interactions was found to be soil context dependent for most fungal species. These results demonstrate that the composition of the AMF community colonizing a host plant is important for plant performance and the consequences of colonization change with soil condition. They also suggest an explanation for why any one plant species supports several species of these fungi

A Blueprint for Promoting Innovation, Interdisciplinary Teamwork, and Collaboration

In response to the myriad of pressures we are experiencing across the higher education landscape, many colleges and universities are exploring different ways to manage and drive change within their institutions. Centres for Teaching and Learning (CTLs) are well-positioned to be high-impact drivers of change in this evolving educational arena. With this comes the expectation that they will emulate and promote innovative practices and creative approaches when addressing many of our most complex academic challenges. Increased agility, cooperation, and strategic foresight within these centres are necessary to detect, respond, and adapt to anticipated future changes and disruptions. However, coordinating such a broad array of resources among CTL departments coupled with interpersonal implications often associated with organizational change and transformation can pose ongoing challenges for leadership. This Organizational Improvement Plan (OIP) will address these issues within the context of a teaching and learning centre at a mid-sized college in Southern Alberta. It will focus specifically on the fluctuating demands and functionality of the centre and the need for increased agility, cooperation, and collaboration among CTL departments to respond more effectively to our continuously shifting circumstances. This is accomplished by exploring the relational and systemic nature of the problem through the lens of complexity leadership theory and its three entangled leadership models: adaptive leadership, enabling leadership, and administrative leadership. The outcome is a strategy theoretically grounded in social cognition theory and a leadership model for cultivating adaptive capacity and leadership competence in strategic foresight