The mesoproterozoic-paleozoic tectonic evolution of Northeast Queensland, Australia

Alexander investigated the tectonic setting and mineralization potential of several key regions across northeast Queensland during the Mesoproterozoic-Paleozoic times. The key findings of this study indicate that collisional tectonics contributed significantly to continent growth across north Queensland

Structural and functional basis for p38-MK2 activated Rsk signalling in Toll-Like receptor-stimulated dendritic cells

Rsk kinases play important roles in several cellular processes such as proliferation, metabolism, and migration. Until recently, Rsk activation was thought to be exclusively initiated by Erk1/2, but in dendritic cells (DC) Rsk is also activated by p38 mitogen-activated protein (MAP) kinase via its downstream substrates, MK2/3. How and why this noncanonical configuration of the MAP kinase pathway is adopted by these key immune cells are not known. We demonstrate that the Erk1/2-activated C-terminal kinase domain of Rsk is dispensable for p38-MK2/3 activation and show that compared with fibroblasts, a greater fraction of p38 and MK2/3 is located in the cytosol of DC prior to stimulation, suggesting a partial explanation for the operation of the noncanonical pathway of Rsk activation in these cells. p38/MK2/3-activated Rsk phosphorylated downstream targets and is physiologically important because in plasmacytoid DC (pDC) stimulated with Toll-like receptor 7 (TLR7) agonists, Erk1/2 activation is very weak relative to p38. As a result, Rsk activation is entirely p38 dependent. We show that this unusual configuration of MAP kinase signaling contributes substantially to production of type I interferons, a hallmark of pDC activation

Evaluation and Validity of a Predictive Equation for Measuring Core Temperature during Exercise in Heat Stress

Exercising in the heat is very common yet can pose significant health risks such as heat exhaustion and heat stroke when core temperature exceeds 38°C and 40°C, respectively. However, current methods of core temperature measurement are invasive and impractical. Recent research indicates that core temperature can be predicted with two non-invasive inputs, heart rate (HR) and skin temperature. PURPOSE: The objective of this study was to assess the validity and reliability of this predictive equation against the direct measurement of core temperature. METHODS: Participants (n = 11) cycled in an environmental chamber (40°C, 40% humidity) at 75% of maximal HR for 45 minutes. Measurements included HR, scapular skin and core temperature, blood pressure, and rating of perceived exertion. Exercise stopped if core temperature exceeded 38.5°C for two consecutive measurements or volitional fatigue. Agreement between predicted and actual core temperature was assessed with Bland–Altman analysis. RESULTS: There was a low correlation (r2 = 0.2) between the direct measure and predicted core temperatures. The Bland–Altman analysis for core minus predicted temperatures showed a bias of 0.14°C and limits of agreement ranging from 0.72°C to −0.45°C. In addition, a large proportion of measurements (40.5%) of the total scores had a difference in temperature greater than ±0.3°C. The predictive equation overpredicted as mean temperature increased from the average core temperature (37°C). CONCLUSION: Based on the narrow temperature range the human body must stay within to prevent heat-related issues, we’ve concluded that the predictive equation lacks sufficient validity and reliability

Seebeck Nanoantennas for Infrared Detection and Energy Harvesting Applications

In this letter we introduce a new type of infrared sensor, based on thermocouple nanoantennas, which enables the energy detection and gathering in the mid-infrared region. The proposed detector combines the Seebeck effect, as a transduction mechanism, with the functionalities of the optical antennas for optical sensing. By using finite-element numerical simulations we evaluate the performance and optical-to-electrical conversion efficiency of the proposed device, unveiling its potential for optical sensing and energy harvesting applications.Comment: 4 pages, 3 figures, Invited paper at EUCAP 201

Determination of Inter-Phase Line Tension in Langmuir Films

A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two co-existing fluid phases driven by an inter-phase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study an 8CB Langmuir film via digitally-imaged Brewster Angle Microscopy (BAM) in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin tether which then slowly relaxes to a circular domain which minimizes the interfacial energy of the system. We process the digital images of the experiment to extract the domain shapes. We then use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics and compare the subsequent images of the experiment to the numerical simulation. The numerical evolutions first verify that our hydrodynamical model can reproduce the observed dynamics. They also allow us to deduce the magnitude of the line tension in the system, often to within 1%. We find line tensions in the range of 200-600 pN; we hypothesize that this variation is due to differences in the layer depths of the 8CB fluid phases.Comment: See (http://www.math.hmc.edu/~ajb/bola/) for related movie

Electric Field Controlled Magnetic Anisotropy in a Single Molecule

We have measured quantum transport through an individual Fe$_4$ single-molecule magnet embedded in a three-terminal device geometry. The characteristic zero-field splittings of adjacent charge states and their magnetic field evolution are observed in inelastic tunneling spectroscopy. We demonstrate that the molecule retains its magnetic properties, and moreover, that the magnetic anisotropy is significantly enhanced by reversible electron addition / subtraction controlled with the gate voltage. Single-molecule magnetism can thus be electrically controlled

The PDK1-Rsk signaling pathway controls Langerhans cell proliferation and patterning

Langerhans cells (LC), the dendritic cells of the epidermis, are distributed in a distinctive regularly spaced array. In the mouse, the LC array is established in the first few days of life from proliferating local precursors, but the regulating signaling pathways are not fully understood. We found that mice lacking the kinase phosphoinositide-dependent kinase 1 selectively lack LC. Deletion of the phosphoinositide-dependent kinase 1 target kinases, ribosomal S6 kinase 1 (Rsk1) and Rsk2, produced a striking perturbation in the LC network: LC density was reduced 2-fold, but LC size was increased by the same magnitude. Reduced LC numbers in Rsk1/2?/? mice was not due to accelerated emigration from the skin but rather to reduced proliferation at least in adults. Rsk1/2 were required for normal LC patterning in neonates, but not when LC were ablated in adults and replaced by bone marrow–derived cells. Increased LC size was an intrinsic response to reduced LC numbers, reversible on LC emigration, and could be observed in wild type epidermis where LC size also correlated inversely with LC density. Our results identify a key signaling pathway needed to establish a normal LC network and suggest that LC might maintain epidermal surveillance by increasing their “footprint” when their numbers are limite