An Iron Refractory Phenotype in Obese Adipose Tissue Macrophages Leads to Adipocyte Iron Overload

Adipocyte iron overload is a maladaptation associated with obesity and insulin resistance. The objective of the current study was to determine whether and how adipose tissue macrophages (ATMs) regulate adipocyte iron concentrations and whether this is impacted by obesity. Using bone marrow-derived macrophages (BMDMs) polarized to M0, M1, M2, or metabolically activated (MMe) phenotypes, we showed that MMe BMDMs and ATMs from obese mice have reduced expression of several iron-related proteins. Furthermore, the bioenergetic response to iron in obese ATMs was hampered. ATMs from iron-injected lean mice increased their glycolytic and respiratory capacities, thus maintaining metabolic flexibility, while ATMs from obese mice did not. Using an isotope-based system, we found that iron exchange between BMDMs and adipocytes was regulated by macrophage phenotype. At the end of the co-culture, MMe macrophages transferred and received more iron from adipocytes than M0, M1, and M2 macrophages. This culminated in a decrease in total iron in MMe macrophages and an increase in total iron in adipocytes compared with M2 macrophages. Taken together, in the MMe condition, the redistribution of iron is biased toward macrophage iron deficiency and simultaneous adipocyte iron overload. These data suggest that obesity changes the communication of iron between adipocytes and macrophages and that rectifying this iron communication channel may be a novel therapeutic target to alleviate insulin resistance.     

Evolution of corrosion products and metal release from Galvalume coatings on steel during short and long-term atmospheric exposures

Non-treated Galvalume (55% Al, 43.4% Zn and 1.6% Si by weight) coatings have been studied through a combination of surface, near surface and bulk analysis after exposure at marine conditions, and for comparison also in an urban test site and in successively more complex short-term laboratory exposures. Slightly polished Galvalume surfaces exhibit dendritic aluminum-rich areas with higher Volta potential compared with interdendritic zinc-rich areas. These effects were not observed on bare as-received surfaces due to the overall presence of aluminum oxide. As a result, preferential corrosion occurred initially in interdendritic areas. The zinc release rate followed the same time-dependence as the surface coverage of zinc-containing phases at the marine exposure condition with zinc predominantly released compared to aluminum. Short term laboratory exposures generated the same main phases as formed at marine conditions. This confirms that the evolution of corrosion products and time dependence of zinc release rates can be explained by the uniform formation of less soluble Al₂O₃, AlOOH and Al(OH)₃ compared to observed zinc-containing phases, e.g. ZnO, zinc hydroxycarbonate and zinc hydroxychloride. The same underlying mechanism is believed to operate also during exposure of Galvalume in the urban site studied.     

Circumventing the blocked rotor test when evaluating model elementsof three phase induction motors

The paper proposes a method that may be used in lieu of the traditional but awkward blocked rotor test to evaluate the AC resistances and the leakage reactances of a polyphase motor. The method provides the element values of the five-element-per-phase Steinmetz model and the six-element-per-phase model of IEEE Standard 112-84. The test procedure is conducted with a freely-rotating motor operated at rated voltage, normal power line frequency and at power levels that may be a fraction of rated load of the machine being tested. Model elements are evaluated from the circular impedance locus of the Steinmetz model or a variation thereof adapted for the six-element-model. Data points on the locus are obtained with the machine operating as a motor and as an asynchronous generator     

Design and characterization of finite-length fiber gratings

A rigorous analysis of the response of fiber Bragg gratings of finite length is presented. For the discrete grating model, we find necessary and sufficient conditions for the response to be realizable as a grating of finite length. These conditions are used to develop a general method for designing gratings with a prescribed length. The design process is divided into two parts. First, we find a realizable reflection spectrum which approximates the target spectrum. Once the spectrum is found, one can determine the associated grating profile by straightforward layer-peeling inverse-scattering or transfer matrix factorization methods. As an example, a dispersionless bandpass filter is designed and compared to the results when the layer-peeling algorithm is applied directly to a windowed impulse response. We also discuss potential applications to grating characterization including regularization and finding the absolute reflection spectrum from a measured, normalized version.     

Mould contaminants on Jarlsberg and Norvegia cheese blocks from four factories.

Visible mould from 225 blocks of the Norwegian semi-hard cheeses Jarlsberg and Norvegia from four factories were subcultured and identified. Altogether 23 different fungal species were detected. The two most important contaminating species were Penicillium commune and P. palitans, constituting 21.4% and 17.9% of the total isolates, respectively. The other dominating contaminants were P. roqueforit spp. roqueforti, Geotrichum candidum, P. solitum and P. crustosum. These species, together with P. commune and P. palitans, represented 80.9% of the total isolates. P. commune, P. palitans, P. roqueforti spp. roqueforti and P. solitum were most common contaminants on cheese produced in all four factories, while G. candidum was found to be important on Jarlsberg cheese from only one factory. P. crustosum was one of the dominating species on Norvegia cheese.     

Empirical Mode Decomposition: Real-Time Implementation and Applications

This paper presents the development of the time-frequency technique, known as the Hilbert–Huang Transform (HHT) into a real-time analysis environment. By looking at the intrinsic elements of the transform we develop a novel strategy for computationally efficient and accurate real-time analysis. Test signals, as well as analysis on EEG and ECG signals for detecting relevant features are presented in support of our methodology. Additional unique insight is shown in some of the intrinsic elements of the algorithm, including some known errors in the use of the popular cubic spline method. Discussions of the primary design considerations and trade-offs are described throughout, aiming at a rounded view of what a real-time HHT implementation involves.     

Release rates of chromium and nickel from 304 and 316 stainless steel during urban atmospheric exposure—a combined field and laboratory study

Release rates of chromium and nickel from pickled and skin passed 304 and 316 stainless steel have been determined during a one-year field exposure in an urban environment (Stockholm, Sweden) and through complementary exposures in artificial rain. Measured annual release rates from 304 stainless steel are 0.25-0.3 mg Cr/m² and 0.3-0.4 mg Ni/m², and slightly higher from 316 stainless steel, 0.35-0.4 mg Cr/m² and 0.7-0.8 mg Ni/m². The release rates decrease as the rain pH increases and exhibit no direct influence by rain intensity. Variations in release rates are thought to be a result of a non-uniformly attack.     

An autonomous vision-based mobile robot

This paper describes the theoretical development and experimental implementation of a complete navigation procedure for use in an autonomous mobile robot for structured environments. Estimates of the vehicle's position and orientation are based on the rapid observation of visual cues located at discrete positions within the environment. The extended Kalman filter is used to combine these visual observations with sensed wheel rotations to produce optimal estimates continuously. The complete estimation procedure, as well as the control algorithm, developed are time independent. A naturally suitable quantity involving wheel rotations is used as the independent variable. One consequence of this choice is that the vehicle speed can be specified independently of the estimation and control algorithms. Reference paths are “taught” by manually leading the vehicle through the desired path. Estimates produced by the extended Kalman filter during this teaching session are then used to represent the geometry of the path. The tracking of taught reference paths is accomplished by controlling the position and orientation of the vehicle relative to the reference path. Time-independence path tracking has necessitated the development of a novel, geometry-based means for advancing along the reference path     

Reviews

Michal Kokowski, Copernicus’s Originality: Towards Integration of Contemporary Copernican Studies (Warsaw: Wydawnictwa Ihn Pan, 2004). 314 pp. pb. ISBN 83‐86062‐27‐4. Sharon E. Kingsland, The Evolution of American Ecology 1890–2000 (Baltimore: Johns Hopkins University Press, 2005). 313 pp. hc. $50. ISBN 0‐8018‐8171‐4. Graeme J.N. Gooday. The Morals of Measurement: Accuracy, Irony, and Trust in Late Victorian Electrical Practice (Cambridge: Cambridge University Press, 2004). xxv, 285 pp. hc. £55. ISBN 0‐521‐43098. Joan Vernet; Ramon Parés (eds.), La Ciència en la Història del Països Catalans. Vol. 1. Dels Àrabs al Renaixement (Valencia: University of Valencia, 2004). 630 pp. hc. €50. ISBN 84‐370‐ 6047‐8. Giuliano Pancaldi, Volta. Science and Culture in the Age of Enlightenment (Princeton and Oxford: Princeton University Press, 2003). 381 pp. hc. £32.50. ISBN 0‐691‐09685‐6. Wolfgang Lefèvre; Jürgen Renn; Urs Schoepfin (eds.), The Power of Images in Early Modern Science (Basel: Birkhäuser Verlag, 2003). 320 pp. pb. CHF 184, € 118. ISBN 3‐7643‐2434‐1. Olivier Darrigol, Worlds of Flow: A History of Hydrodynamics from the Bernoullis to Prandtl (Oxford: Oxford University Press, 2005). 356 pp. hc. L35.00. ISBN 0‐19‐856843‐6. Ad Meskens, Joannes della Faille s.j.: Mathematics, Modesty and Missed Opportunities (Brussel: Institut Historique Belge de Rome, 2005). 175 pp. hc. ISBN 90‐74461‐53‐0. Aant Elzinga; Torgny Nordin; David Turner; Urban Wråkberg (eds.), Antarctic Challenges. Historical and Current Perspectives on Otto Nordenskjöld’s Antartic Expedition 1901–1903 (Göteborg: Royal Society of Arts and Sciences, 2004). 330 pp. hc. $93. ISBN 91‐85252‐64‐6. Klaus‐Heinrich Peters, Schönheit, Exaktheit, Wahrheit: Der Zusammenhang von Mathematik und Physik am Beispiel der Geschichte der Distributionen (Berlin: GNT‐Verlag, 2005). 272 pp. pb. € 32.00. ISBN 3‐928186‐74‐4.