613 research outputs found
Decarbonising Urban Freight Transport: Experimentations in European Research Projects
One of the objectives of European research programs is to decarbonize freight transport while maintaining its competitiveness and economic strength, reduce negative externalities such as pollutant emissions, congestion and accidents, and foster innovation. Multiple initiatives have started in Europe to reach these objectives and this paper reviews some of these schemes in the field of urban freight transport. It is based mainly on 3 EC-funded projects (BESTFACT (2016), SOLUTION (2015) and SMARTFUSION (2016)). These 3 projects are either testing (Smartfusion) or examining and disseminating European ‘new solutions’ or ‘best practices’ in freight transport. The paper mainly focuses on the most decarbonizing solutions
Chiral recognition for the complexation dynamics of β-cyclodextrin with the enantiomers of 2-naphthyl-1-ethanol
The focus of this study is to understand the origin of the chiral recognition for a host–guest system containing complexes with different stoichiometries. Each enantiomer of 2-naphthyl-1-ethanol forms two different 1:1 complexes with β-cyclodextrin, leading to the formation of three different 2:2 complexes. One of these 2:2 complexes leads to excimer emission of the guest. Fluorescence studies were employed to determine the binding isotherms for the 1:1 and 2:2 complexes. No chiral discrimination was directly observed for the formation of the 1:1 complexes, while higher equilibrium constants (29% from binding isotherms and 40% from kinetic studies) were observed for the formation of the 2:2 complexes with (R)-2-naphthyl-1-ethanol when compared to the formation of the 2:2 complexes formed from (S)-2-naphthyl-1-ethanol. The relaxation kinetics was studied using stopped-flow experiments. The formation of the 2:2 complexes was followed by detecting the excimer emission from one of the 2:2 complexes. The relaxation kinetics was faster for (S)-2-naphthyl-1-ethanol, where a higher dissociation rate constant, by 47%, was observed, suggesting that the chiral discrimination occurs because the interaction between two cyclodextrins is more favorable for the complexes containing (R)-2-naphthyl-1-ethanol when compared to (S)-2-naphthyl-1-ethanol. The same overall equilibrium constants were observed for the 1:1 complexes with both enantiomers showing that at a given cyclodextrin concentration the sum of the two types of 1:1 complexes is the same for both enantiomers. However, analysis of the binding isotherms indicates that the ratio between the two different 1:1 complexes for each enantiomer was different for (R)- and (S)-2-naphthyl-1-ethanol
Nanogranular MgB2 thin films on SiC buffered Si substrates prepared by in-situ method
MgB2 thin films were deposited on SiC buffered Si substrates by sequential
electron beam evaporation of B-Mg bilayer followed by in-situ annealing. The
application of a SiC buffer layer enables the maximum annealing temperature of
830 C. The Transmission Electron Microscopy analysis confirms the growth of a
nanogranular MgB2 film and the presence of a Mg2Si compound at the surface of
the film. The 150-200 nm thick films show a maximum zero resistance critical
temperature TC0 above 37 K and a critical current density JC ~ 106 A/cm2 at
11K.Comment: 7 pages, 6 figures, submitted to Applied Physics Letter
Germination of phagocytosed E. cuniculi spores does not significantly contribute to parasitophorous vacuole formation in J774 cells
The obligate intracellular microsporidia have developed a unique invasion mechanism to infect their host cells. Spores explosively evert a tube-like structure and extrude the infectious spore content through this organelle into the host cell. Spores from species of the genus Encephalitozoon were also shown to be efficiently internalized by phagocytosis, which led to the hypothesis that spore germination from inside a phagosome might contribute to the infection process. Here, we challenge this hypothesis by quantifying Encephalitozoon cuniculi infection rates of J774 cells that were incubated with the phagocytosis inhibitor cytochalasin D. We demonstrate that the invasion rate in cytochalasin D-treated cells is identical to untreated controls, although phagocytic uptake of E. cuniculi spores was less than 10% of control samples. This study suggests that germination of phagocytosed spores is not a significant infection mode for E. cuniculi
Quasi-fission reactions as a probe of nuclear viscosity
Fission fragment mass and angular distributions were measured from the
^{64}Ni+^{197}Au reaction at 418 MeV and 383 MeV incident energy. A detailed
data analysis was performed, using the one-body dissipation theory implemented
in the code HICOL. The effect of the window and the wall friction on the
experimental observables was investigated. Friction stronger than one-body was
also considered. The mass and angular distributions were consistent with
one-body dissipation. An evaporation code DIFHEAT coupled to HICOL was
developed in order to predict reaction time scales required to describe
available data on pre-scission neutron multiplicities. The multiplicity data
were again consistent with one-body dissipation. The cross-sections for touch,
capture and quasi-fission were also obtained.Comment: 25 pages REVTeX, 3 tables, 13 figures, submitted to Phys. Rev
Excited States in 52Fe and the Origin of the Yrast Trap at I=12+
Excited states in 52Fe have been determined up to spin 10\hbar in the
reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the
GASP array. The excitation energy of the yrast 10+ state has been determined to
be 7.381 MeV, almost 0.5 MeV above the well known \beta+-decaying yrast 12+
state, definitely confirming the nature of its isomeric character. The mean
lifetimes of the states have been measured by using the Doppler Shift
Attenuation method. The experimental data are compared with spherical shell
model calculations in the full pf-shell.Comment: 9 pages, RevTeX, 7 figures include
Spectroscopic factors for bound s-wave states derived from neutron scattering lengths
A simple and model-independent method is described to derive neutron
single-particle spectroscopic factors of bound s-wave states in nuclei from neutron scattering lengths. Spectroscopic factors
for the nuclei ^{13}C, ^{14}C, ^{16}N, ^{17}O, ^{19}O, ^{23}Ne, ^{37}Ar, and
^{41}Ar are compared to results derived from transfer experiments using the
well-known DWBA analysis and to shell model calculations. The scattering length
of ^{14}C is calculated from the ^{15}C_{g.s.} spectroscopic factor.Comment: 9 pages (uses revtex), no figures, accepted for publication in PRC,
uuencoded tex-files and postscript-files available at
ftp://is1.kph.tuwien.ac.at/pub/ohu/Thermal.u
Reaction rates for Neutron Capture Reactions to C-, N- and O-isotopes to the neutron rich side of stability
The reaction rates of neutron capture reactions on light nuclei are important
for reliably simulating nucleosynthesis in a variety of stellar scenarios.
Neutron capture reaction rates on neutron-rich C-, N-, and O-isotopes are
calculated in the framework of a hybrid compound and direct capture model. The
results are tabulated and compared with the results of previous calculations as
well as with experimental results.Comment: 33 pages (uses revtex) and 9 postscript figures, accepted for
publication in Phys. Rev.
Predicting temporary threshold shifts in a bottlenose dolphin (Tursiops truncatus) : the effects of noise level and duration
Author Posting. © Acoustical Society of America, 2009. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 125 (2009): 1816-1826, doi:10.1121/1.3068456.Noise levels in the ocean are increasing and are expected to affect marine mammals. To examine the auditory effects of noise on odontocetes, a bottlenose dolphin (Tursiops truncatus) was exposed to octave-band noise (4–8 kHz) of varying durations (<2–30 min) and sound pressures (130–178 dB re 1 µPa). Temporary threshold shift (TTS) occurrence was quantified in an effort to (i) determine the sound exposure levels (SELs) (dB re 1 µPa2 s) that induce TTS and (ii) develop a model to predict TTS onset. Hearing thresholds were measured using auditory evoked potentials. If SEL was kept constant, significant shifts were induced by longer duration exposures but not for shorter exposures. Higher SELs were required to induce shifts in shorter duration exposures. The results did not support an equal-energy model to predict TTS onset. Rather, a logarithmic algorithm, which increased in sound energy as exposure duration decreased, was a better predictor of TTS. Recovery to baseline hearing thresholds was also logarithmic (approximately −1.8 dB/doubling of time) but indicated variability including faster recovery rates after greater shifts and longer recoveries necessary after longer duration exposures. The data reflected the complexity of TTS in mammals that should be taken into account when predicting odontocete TTS.This work was funded by the
Office of Naval Research Grant No. 00014-098-1-687 to
P.E.N. and the support of Bob Gisiner and Mardi Hasting is
noted. Additional support came from SeaSpace to T.A.M
Identification of the Microsporidian Encephalitozoon cuniculi as a New Target of the IFNγ-Inducible IRG Resistance System
The IRG system of IFNγ-inducible GTPases constitutes a powerful resistance mechanism in mice against Toxoplasma gondii and two Chlamydia strains but not against many other bacteria and protozoa. Why only T. gondii and Chlamydia? We hypothesized that unusual features of the entry mechanisms and intracellular replicative niches of these two organisms, neither of which resembles a phagosome, might hint at a common principle. We examined another unicellular parasitic organism of mammals, member of an early-diverging group of Fungi, that bypasses the phagocytic mechanism when it enters the host cell: the microsporidian Encephalitozoon cuniculi. Consistent with the known susceptibility of IFNγ-deficient mice to E. cuniculi infection, we found that IFNγ treatment suppresses meront development and spore formation in mouse fibroblasts in vitro, and that this effect is mediated by IRG proteins. The process resembles that previously described in T. gondii and Chlamydia resistance. Effector (GKS subfamily) IRG proteins accumulate at the parasitophorous vacuole of E. cuniculi and the meronts are eliminated. The suppression of E. cuniculi growth by IFNγ is completely reversed in cells lacking regulatory (GMS subfamily) IRG proteins, cells that effectively lack all IRG function. In addition IFNγ-induced cells infected with E. cuniculi die by necrosis as previously shown for IFNγ-induced cells resisting T. gondii infection. Thus the IRG resistance system provides cell-autonomous immunity to specific parasites from three kingdoms of life: protozoa, bacteria and fungi. The phylogenetic divergence of the three organisms whose vacuoles are now known to be involved in IRG-mediated immunity and the non-phagosomal character of the vacuoles themselves strongly suggests that the IRG system is triggered not by the presence of specific parasite components but rather by absence of specific host components on the vacuolar membrane.Grants from the Deutsche Forschungsgemeinschaft: SFB635, 670, 680, SPP1399
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