The macrophage at the intersection of immunity and metabolism in obesity

Obesity is a worldwide pandemic representing one of the major challenges that societies face around the globe. Identifying the mechanisms involved in its development and propagation will help the development of preventative and therapeutic strategies that may help control its rising rates

Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer

Oxalic and other small dicarboxylic acids have been reported as important water-soluble organic constituents of atmospheric aerosols from different environments. Their molecular distributions are generally characterized by the predominance of oxalic acid (C2) followed by malonic (C3) and/or succinic (C4) acids. In this study, we collected marine aerosols from the Arctic Ocean during late summer in 2009 when sea ice was retreating. The marine aerosols were analyzed for the molecular distributions of dicarboxylic acids as well as ketocarboxylic acids and α-dicarbonyls to better understand the source of water-soluble organics and their photochemical processes in the high Arctic marine atmosphere. We found that diacids are more abundant than ketoacids and α-dicarbonyls, but their concentrations are generally low (< 30ng m^[-3]), except for one sample (up to 70ng m^[-3]) that was collected near the mouth of Mackenzie River during clear sky condition. Although the molecular compositions of diacids are in general characterized by the predominance of oxalic acid, a depletion of C2 was found in two samples in which C4 became the most abundant. Similar depletion of oxalic acid has previously been reported in the Arctic aerosols collected at Alert after polar sunrise and in the summer aerosols from the coast of Antarctica. Because the marine aerosols that showed a depletion of C2 were collected under the overcast and/or foggy conditions, we suggest that a photochemical decomposition of oxalic acid may have occurred in aqueous phase of aerosols over the Arctic Ocean via the photo dissociation of oxalate-Fe (III) complex. We also determined stable carbon isotopic compositions (δ13C) of bulk aerosol carbon and individual diacids. The δ13C of bulk aerosols showed -26.5‰ (range: -29.7 to -24.7‰), suggesting that marine aerosol carbon is derived from both terrestrial and marine organic materials. In contrast, oxalic acid showed much larger δ13C values (average: -20.9‰, range: -24.7‰ to -17.0‰) than those of bulk aerosol carbon. Interestingly, δ13C values of oxalic acid were higher than C3 (av. -26.6‰) and C4 (-25.8‰) diacids, suggesting that oxalic acid is enriched with 13C due to its photochemical processing (aging) in the marine atmosphere

Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer

Oxalic and other small dicarboxylic acids have been reported as important water-soluble organic constituents of atmospheric aerosols from different environments. Their molecular distributions are generally characterized by the predominance of oxalic acid (C&lt;sub&gt;2&lt;/sub&gt;) followed by malonic (C&lt;sub&gt;3&lt;/sub&gt;) and/or succinic (C&lt;sub&gt;4&lt;/sub&gt;) acids. In this study, we collected marine aerosols from the Arctic Ocean during late summer in 2009 when sea ice was retreating. The marine aerosols were analyzed for the molecular distributions of dicarboxylic acids as well as ketocarboxylic acids and α-dicarbonyls to better understand the source of water-soluble organics and their photochemical processes in the high Arctic marine atmosphere. We found that diacids are more abundant than ketoacids and α-dicarbonyls, but their concentrations are generally low (&lt; 30 ng m&lt;sup&gt;−3&lt;/sup&gt;), except for one sample (up to 70 ng m&lt;sup&gt;−3&lt;/sup&gt;) that was collected near the mouth of Mackenzie River during clear sky condition. Although the molecular compositions of diacids are in general characterized by the predominance of oxalic acid, a depletion of C&lt;sub&gt;2&lt;/sub&gt; was found in two samples in which C&lt;sub&gt;4&lt;/sub&gt; became the most abundant. Similar depletion of oxalic acid has previously been reported in the Arctic aerosols collected at Alert after polar sunrise and in the summer aerosols from the coast of Antarctica. Because the marine aerosols that showed a depletion of C&lt;sub&gt;2&lt;/sub&gt; were collected under the overcast and/or foggy conditions, we suggest that a photochemical decomposition of oxalic acid may have occurred in aqueous phase of aerosols over the Arctic Ocean via the photo dissociation of oxalate-Fe (III) complex. We also determined stable carbon isotopic compositions (&amp;delta;&lt;sup&gt;13&lt;/sup&gt;C) of bulk aerosol carbon and individual diacids. The &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C of bulk aerosols showed −26.5&amp;permil; (range: −29.7 to −24.7&amp;permil;, suggesting that marine aerosol carbon is derived from both terrestrial and marine organic materials. In contrast, oxalic acid showed much larger &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C values (average: −20.9&amp;permil;, range: −24.7&amp;permil; to −17.0&amp;permil;) than those of bulk aerosol carbon. Interestingly, &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C values of oxalic acid were higher than C&lt;sub&gt;3&lt;/sub&gt; (av. −26.6&amp;permil;) and C&lt;sub&gt;4&lt;/sub&gt; (−25.8&amp;permil;) diacids, suggesting that oxalic acid is enriched with &lt;sup&gt;13&lt;/sup&gt;C due to its photochemical processing (aging) in the marine atmosphere

Multicolor photochromic films deposited on flexible substrates by reactive magnetron sputtering

International audienc

Standard methods for Nosema

Methods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity test