Soluble FAS and transforming growth factor beta 2 in infections with viral and bacterial zoonoses

Određivali smo razine sFas (signalna receptor molekula koja biva otpuštena tijekom apoptoze u cirkulirajućem obliku) i TGF-β2 (multifunkcionalni citokin) u bolesnika s različitim zoonozama. Serumi su dobiveni od bolesnika hospitaliziranih u Klinici za infektivne bolesti »Dr. Fran Mihaljević«, Zagreb, Hrvatska, s dijagnozama: hemoragijska vrućica s bubrežnim sindromom – HVBS (n=20), leptospiroza (n=9), borelioza (n=7) ili krpeljni meningoencefalitis – KME (n=7). Za mjerenje razina sFas i TGF-β2 u serumima koristili smo ELISA kitove prema uputama proizvođača. Značajno povišena razina sFas je nađena u svih bolesnika. Ipak, bolesnici s KME ili boreliozom imali su značajno niže razine nego bolesnici s leptospirozom. Nasuprot tome, bolesnici s KME ili boreliozom su imali značajno više razine TGF-β2 nego zdrave kontrole. Naši preliminarni podaci ukazuju da bi povišene razine sFas i TGF-β2 mogle imati ulogu u imunopatogenezi ispitivanih virusnih i bakterijskih zoonoza.We determined levels of sFas (signal receptor molecule released during apoptosis in a soluble circulating form) and TGF-β2 (multifunctional cytokine) in patients with different zoonoses. Serum samples were obtained from patients hospitalized at the University Hospital for Infectious Diseases, Zagreb, Croatia with diagnoses of hemorrhagic fever with renal syndrome – HFRS, (n=20), leptospirosis (n=9), Lyme borreliosis (n=7), or tick-borne encephalitis – TBE (n=7). In all sera samples the levels of sFAS or TGF-β2 levels were measured using ELISAkits according to the manufacturer\u27s protocol. Significant increase in the levels of sFas was found in all patients. However, the patients with TBE or Lyme borreliosis had significantly lower levels than patients with leptospirosis. In contrary, patients with TBE or Lyme borreliosis had significantly higher levels of TGF-β2 than healthy controls. Our preliminary data indicate that an increase of sFas and TGF-β2 levels may have a role in the immunopathogenesis of tested viral and bacterial zoonoses

Femtosecond x-ray diffraction from an aerosolized beam of protein nanocrystals

We demonstrate near-atomic-resolution Bragg diffraction from aerosolized single granulovirus crystals using an x-ray free-electron laser. The form of the aerosol injector is nearly identical to conventional liquid-microjet nozzles, but the x-ray-scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. This approach provides a route to study the weak diffuse or lattice-transform signal arising from small crystals. The high speed of the particles is particularly well suited to upcoming MHz-repetition-rate x-ray free-electron lasers

Narrow-band tunable terahertz emission from ferrimagnetic Mn3-xGa thin films

Narrow-band terahertz emission from coherently excited spin precession in metallic ferrimagnetic Mn3-xGa Heusler alloy nanofilms has been observed. The efficiency of the emission, per nanometer film thickness, is comparable or higher than that of classical laser-driven terahertz sources based on optical rectification. The center frequency of the emission from the films can be tuned precisely via the film composition in the range of 0.20-0.35 THz, making this type of metallic film a candidate for efficient on-chip terahertz emitters. Terahertz emission spectroscopy is furthermore shown to be a sensitive probe of magnetic properties of ultra-thin films. Published by AIP Publishing

The role of parasites in the invasion success of the exotic brine shrimp Artemia Franciscana in the Meditarranean region

Trabajo presentado en el Symposium for European Freshwater Science, celebardo en Girona del 27 de junio al 1 de julio de 2011.Biological invasions are main threats to biodiversity at global scale and increasing numbers of studies suggest that parasites may have a role. However, the mechanism through which parasites may influence the outcome of the invasion is poorly understood. Here we provide evidence supporting the role of parasites as potential agents mediating the competitive exclusion of Mediterranean brine shrimps Artemia (A. parthenogenetica and A. salina) by the exotic American A. franciscana, using different native and invasive populations from South Spain and South France. Our results revealed high rates of infection by cestodes in native brine shrimps, sometimes with extreme prevalences of up to 100%. In contrast, A. franciscana populations showed very low diversity, prevalence and burden of cestodes. The effect of parasites in native populations was multiple, ranging from reproduction and survival, to life history traits, microhabitat selection and diet. Infection strongly reduced host fitness by both, reducing fecundity (parasite castration) and indirectly increasing predation by birds final hosts as revealed by prey choice experiments. We found evidence that high rate of parasitism (particularly the castrating parasite Flamingolepis liguloides, the most prevalent cestode in natives but nearly absent in the exotic Artemia), indirectly affected the life-history strategy of non infected individuals, inducing for example earlier maturation. Moreover cestodes influenced spatial (vertical and horizontal) distribution of the host, altering the diet as revealed by isotopic analysis. Contrasting with the strong impact of parasites in native populations, we have never observed any pathology (castration, behavioural alteration, etc) associated with infection in the exotic species. Overall, the results of this study suggest that the large impact of cestode on the native, but not the invading species, is likely to confer a decisive competitive advantage to the invader, contributing to explain the demographic success of A. franciscana in the Mediterranean region.Peer reviewe

IPCC reasons for concern regarding climate change risks

The reasons for concern framework communicates scientific understanding about risks in relation to varying levels of climate change. The framework, now a cornerstone of the IPCC assessments, aggregates global risks into five categories as a function of global mean temperature change. We review the framework's conceptual basis and the risk judgments made in the most recent IPCC report, confirming those judgments in most cases in the light of more recent literature and identifying their limitations. We point to extensions of the framework that offer complementary climate change metrics to global mean temperature change and better account for possible changes in social and ecological system vulnerability. Further research should systematically evaluate risks under alternative scenarios of future climatic and societal conditions

Time and Money: Substitutes in Real Terms and Complements in Satisfactions

Time and money are basic commodities in the utility function and are substitutes in real terms. To a certain extent, having time and money is a matter of either/or, depending on individual preferences and budget constraints. However, satisfaction with time and satisfaction with money are typically complements, i.e., individuals tend to be equally satisfied with both domains. In this paper, we provide an explanation for this apparent paradox through the analysis of the simultaneous determination of economic satisfaction and leisure satisfaction. We test some hypotheses, including the hypothesis that leisure satisfaction depends on both the quantity and quality of leisure-where quality is proxied by good intensiveness and social intensiveness. Our results show that both the quantity and the quality of leisure are important determinants of leisure satisfaction, and, since having money contributes to the quality of leisure, this explains the empirical findings of the satisfactions being complementary at the same time as the domains are substitutes. Interestingly, gender matters. Intra-household effects and especially individual characteristics are more pronounced for women than for men for both domain satisfactions. Additionally, good intensiveness is more important for men (e.g., housing conditions), whereas social intensiveness is more important for women (e.g., the presence of children and participation in leisure-time activities)

Ferromagnetism in graphene nanoribbons: split versus oxidative unzipped ribbons

Two types of graphene nanoribbons: (a) potassium-split graphene nanoribbons (GNRs), and (b) oxidative unzipped and chemically converted graphene nanoribbons (CCGNRs) were investigated for their magnetic properties using the combination of static magnetization and electron spin resonance measurements. The two types of ribbons possess remarkably different magnetic properties. While the low temperature ferromagnet-like feature is observed in both types of ribbons, such room temperature feature persists only in potassium-split ribbons. The GNRs show negative exchange bias, but the CCGNRs exhibit a 'positive exchange bias'. Electron spin resonance measurements infer that the carbon related defects may responsible for the observed magnetic behaviour in both types of ribbons. Furthermore, proton hyperfine coupling strength has been obtained from hyperfine sublevel correlation experiments performed on the GNRs. Electron spin resonance provides no indications for the presence of potassium (cluster) related signals, emphasizing the intrinsic magnetic nature of the ribbons. Our combined experimental results may infer the coexistence of ferromagnetic clusters with anti-ferromagnetic regions leading to disordered magnetic phase. We discuss the origin of the observed contrast in the magnetic behaviours of these two types of ribbons

Search for dark matter annual modulation with DarkSide-50

Dark matter induced event rate in an Earth-based detector is predicted to show an annual modulation as a result of the Earth's orbital motion around the Sun. We searched for this modulation signature using the ionization signal of the DarkSide-50 liquid argon time projection chamber. No significant signature compatible with dark matter is observed in the electron recoil equivalent energy range above $40~{\rm eV_{ee}}$, the lowest threshold ever achieved in such a search.Comment: 8 pages, 4 figure

Search for dark matter-nucleon interactions via Migdal effect with DarkSide-50

Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ionization electron adds to the energy deposited by the recoiling nuclear system and allows for the detection of interactions of sub-GeV/c$^2$ mass dark matter. We present new constraints for sub-GeV/c$^2$ dark matter using the dual-phase liquid argon time projection chamber of the DarkSide-50 experiment with an exposure of (12306 $\pm$ 184) kg d. The analysis is based on the ionization signal alone and significantly enhances the sensitivity of DarkSide-50, enabling sensitivity to dark matter with masses down to 40 MeV/c$^2$. Furthermore, it sets the most stringent upper limit on the spin independent dark matter nucleon cross section for masses below $3.6$ GeV/c$^2$.Comment: 7 pages, 3 figure