Facile Preparation of Organic Nanoparticles by Interfacial Cross-Linking of Reverse Micelles and Template Synthesis of Subnanometer Au−Pt Nanoparticles

A single- and a double-tailed cationic surfactant with the triallylammonium headgroup formed reverse micelles (RMs) in heptane/chloroform containing a small amount of water. The reverse micelles were cross-linked at the interface upon UV irradiation in the presence of a water-soluble dithiol cross-linker and a photoinitiator. The resulting interfacially cross-linked reverse micelles (ICRMs) of the single-tailed surfactant aggregated in a solvent-dependent fashion, whereas those of the double-tailed were identical in size as the corresponding RMs. The ICRMs could extract anionic metal salts, such as AuCl4− and PtCl62−, from water into the organic phase. Au and Pt metal nanoparticles were produced upon reduction of metal salts. The covalent nature of the ICRMs made the template synthesis highly predictable, with the size of the metal particles controlled by the amount of the metal salt and the method of reduction. Nanoalloys were obtained by combining two metal precursors in the same reaction. Reduction of the ICRM-entrapped aurate also occurred without any external reducing agents, and the gold nanoparticles differed dramatically from those obtained through sodium borohydride reduction. The same template allowed the preparation of luminescent Au4, Au8, and Au13−Au23 clusters, as well as gold nanoparticles several nanometers in size, simply by using different amounts of gold precursor and reducing conditions

LXR Deficiency Confers Increased Protection against Visceral Leishmania Infection in Mice

Leishmania spp. are protozoan single-cell parasites that are transmitted to humans by the bite of an infected sand fly, and can cause a wide spectrum of disease, ranging from self-healing skin lesions to potentially fatal systemic infections. Certain species of Leishmania that cause visceral (systemic) disease are a source of significant mortality worldwide. Here, we use a mouse model of visceral Leishmania infection to investigate the effect of a host gene called LXR. The LXRs have demonstrated important functions in both cholesterol regulation and inflammation. These processes, in turn, are closely related to lipid metabolism and the development of atherosclerosis. LXRs have also previously been shown to be involved in protection against other intracellular pathogens that infect macrophages, including certain bacteria. We demonstrate here that LXR is involved in susceptibility to Leishmania, as animals deficient in the LXR gene are much more resistant to infection with the parasite. We also demonstrate that macrophages lacking LXR kill parasites more readily, and make higher levels of nitric oxide (an antimicrobial mediator) and IL-1β (an inflammatory cytokine) in response to Leishmania infection. These results could have important implications in designing therapeutics against this deadly pathogen, as well as other intracellular microbial pathogens

Chimpanzee Ethnography Reveals Unexpected Cultural Diversity

Human ethnographic knowledge covers hundreds of societies, whereas chimpanzee ethnography encompasses at most 15 communities. Using termite fishing as a window into the richness of chimpanzee cultural diversity, we address a potential sampling bias with 39 additional communities across Africa. Previously, termite fishing was known from eight locations with two distinguishable techniques observed in only two communities. Here, we add nine termite-fishing communities not studied before, revealing 38 different technical elements, as well as community-specific combinations of three to seven elements. Thirty of those were not ecologically constrained, permitting the investigation of chimpanzee termite-fishing culture. The number and combination of elements shared among individuals were more similar within communities than between them, thus supporting community-majority conformity via social imitation. The variation in community-specific combinations of elements parallels cultural diversity in human greeting norms or chopstick etiquette. We suggest that termite fishing in wild chimpanzees shows some elements of cumulative cultural diversity

Le collezioni museali naturalistiche come fondamentale risorsa nella ricerca scientifica: distribuzione spazio-temporale dei reperti di grandi vertebrati marini nei musei italiani

Il patrimonio culturale marino italiano ha per tradizione e storia un’imponente ricchezza di collezioni museali naturalistiche, con migliaia di reperti ossei e tassidermizzati di vertebrati marini, costruite in oltre due secoli di attività. I reperti museali rappresentano la conoscenza primaria ed unica della biodiversità organismica ed ecosistemica storica del Mediterraneo e costituiscono un ampio archivio di tessuti e dati scientifici potenzialmente sfruttabile grazie alle nuove tecnologie biomolecolari per comprendere pattern, processi e possibili cause della perdita di biodiversità, degrado degli ecosistemi e declino delle popolazioni. Con l’obiettivo di ricostruire le traiettorie evolutive ed ecologiche di specie e popolazioni di grandi predatori marini del Mediterraneo (cetacei ed elasmobranchi) abbiamo costituito un network di 25 collezioni osteologiche museali (universitarie e civiche) e private italiane, da cui abbiamo ottenuto oltre 500 campioni (fotografie geometriche e tessuti biologici di crani, rostri, mascelle, vertebre e denti) di individui storici di Delphinus delphis, Stenella coeruleoalba, Tursiops truncatus, Carcharodon carcharias, quattro specie di pesce sega dei generi Pristis e Anoxypristis, otto specie di cetacei mediterranei e la foca monaca (Monachus monachus). Il presente lavoro descrive i risultati, in termini di numero e di distribuzione, dei reperti di alcune specie di grandi predatori marini e mette in evidenza il valore storico, culturale e scientifico delle collezioni museali, in particolar modo per gruppi di organismi di particolare interesse conservazionistico