Since the global financial crisis, interest rate swap rates, which represent future uncollateralized interbank borrowing, have fallen below maturity-matched Treasury rates. This is surprising, ...because US Treasuries, which are deemed expensive because of superior liquidity and safety, should produce yields that are lower than those of swap rates. We show, by no-arbitrage, that sovereign default risk explains negative swap spreads even without frictions such as balance sheet constraints, convenience yield, and hedging demand. We support this explanation with an equilibrium model that jointly accounts for macroeconomic fundamentals and the term structures of interest and US credit default swap rates.
The rather few cases of humans infected by HIV-1 N, O, or P raise the question of their incomplete adaptation to humans. We hypothesized that early postentry restrictions may be relevant for the ...impaired spread of these HIVs. One of the best-characterized species-specific restriction factors is TRIM5α. HIV-1 M can escape human (hu) TRIM5α restriction by binding cyclophilin A (CYPA, also known as PPIA, peptidylprolyl isomerase A) to the so-called CYPA-binding loop of its capsid protein. How non-M HIV-1s interact with huTRIM5α is ill-defined. By testing full-length reporter viruses (Δ
) of HIV-1 N, O, P, and SIVgor (simian IV of gorillas), we found that in contrast to HIV-1 M, the nonpandemic HIVs and SIVgor showed restriction by huTRIM5α. Work to identify capsid residues that mediate susceptibility to huTRIM5α revealed that residue 88 in the capsid CYPA-binding loop was important for such differences. There, HIV-1 M uses alanine to resist, while non-M HIV-1s have either valine or methionine, which avail them for huTRIM5α. Capsid residue 88 determines the sensitivity to TRIM5α in an unknown way. Molecular simulations indicated that capsid residue 88 can affect
-to-
isomerization patterns on the capsids of the viruses we tested. These differential CYPA usages by pandemic and nonpandemic HIV-1 suggest that the enzymatic activity of CYPA on the viral core might be important for its protective function against huTRIM5α.
West Africa and the adjacent oceanic regions are very important locations for studying dust properties and their influence on weather and climate. The SHADOW (study of SaHAran Dust Over West Africa) ...campaign is performing a multiscale and multilaboratory study of aerosol properties and dynamics using a set of in situ and remote sensing instruments at an observation site located at the IRD (Institute for Research and Development) in Mbour, Senegal (14° N, 17° W). In this paper, we present the results of lidar measurements performed during the first phase of SHADOW (study of SaHAran Dust Over West Africa) which occurred in March–April 2015. The multiwavelength Mie–Raman lidar acquired 3β + 2α + 1δ measurements during this period. This set of measurements has permitted particle-intensive properties, such as extinction and backscattering Ångström exponents (BAE) for 355/532 nm wavelengths' corresponding lidar ratios and depolarization ratio at 532 nm, to be determined. The mean values of dust lidar ratios during the observation period were about 53 sr at both 532 and 355 nm, which agrees with the values observed during the SAMUM-1 and SAMUM-2 campaigns held in Morocco and Cabo Verde in 2006 and 2008. The mean value of the particle depolarization ratio at 532 nm was 30 ± 4.5 %; however, during strong dust episodes this ratio increased to 35 ± 5 %, which is also in agreement with the results of the SAMUM campaigns. The backscattering Ångström exponent during the dust episodes decreased to ∼ −0.7, while the extinction Ångström exponent, though negative, was greater than −0.2. Low values of BAE can likely be explained by an increase in the imaginary part of the dust refractive index at 355 nm compared to 532 nm. The dust extinction and backscattering coefficients at multiple wavelengths were inverted to the particle microphysics using the regularization algorithm and the model of randomly oriented spheroids. The analysis performed has demonstrated that the spectral dependence of the imaginary part of the dust refractive index may significantly influence the inversion results and should be taken into account.
Background
Multidrug‐resistant (MDR) bacteria are a growing concern worldwide. The aim of this study was to describe the epidemiology and risk factors of MDR bacteria detected in respiratory invasive ...samples during hospitalization in the intensive care unit (ICU) after lung transplantation (LT).
Methods
This study was based on a retrospective analysis of 176 patients hospitalized in the ICU after LT in 2006–2012. Respiratory invasive samples were performed according to a routine protocol. MDR pathogens were defined according to in vitro susceptibility tests.
Results
A total of 1176 bacteria were cultured. Susceptibility testing was performed on 1046 strains and 404 (39%) MDR were detected in 90 (51%) patients. Pseudomonas aeruginosa, coagulase‐negative staphylococci, and Enterobacteriaceae (mainly Enterobacter species) were the most common MDR pathogens. On multivariate analysis, an ICU stay >14 days, presence of a tracheostomy, and previous exposure to broad‐spectrum antibiotics were associated with MDR acquisition (odds ratio OR 3.7; 95% confidence interval 1.69–8.12; OR 3.28 1.05–10.28; and OR 2.25 1.17–4.34, respectively). We consistently observed an increasing emergence of resistance to several antibiotics, from week 1 to week 4 of ICU hospitalization: for ticarcillin, piperacillin–tazobactam, ceftazidime, imipenem/cilastatin, amikacin, and ciprofloxacin in P. aeruginosa; and for piperacillin–tazobactam, cefepime, and amikacin in Enterobacteriaceae.
Conclusion
A large proportion of MDR bacteria are detected on respiratory invasive samples in LT patients, and the risk of their emergence is mainly determined by the previous exposure to broad‐spectrum antibiotics and the length of ICU stay. Adequate treatment requires broad‐spectrum empiric antibiotic therapy.
The atmospheric composition measured at the Pic du Midi high-altitude observatory (2875 m MSL) in the French Pyrenees is frequently affected by upward transport of boundary layer air during anabatic ...circulations at different scales. The Pyrenean Platform for Observation of the Atmosphere (P2OA) includes two observatories located 28 km apart: at the Pic du Midi and at a low-altitude site (580 m MSL) located in the plain north of the mountain chain. From a 10-yr-long data series collected at P2OA, three different methods are used to detect thermally induced circulations. The methods are based on observations collected independently at three key locations in the plain–mountain circulation cell: within the altitude return flow above the plain, close to the surface in the plain, and at the mountaintop. The main aims are 1) to present and compare the three detection methods and 2) to evaluate the impact of thermally driven circulations on in situ air composition measurements at the Pic du Midi. The first method uses radar wind measurements at 3000 and 5000 m above the plain to detect the return flow of the plain–mountain circulation. The second, which is based on surface wind data from the plain site, reveals days during which surface thermally induced winds occur locally. The third method, which is based on surface data at the mountaintop, focuses on diurnal moisture cycles to rank days with decreasing anabatic influence. We then compare the three independent detection methods, discuss possible connections among thermal circulations at different scales and locations, and present an evaluation of their impact on in situ atmospheric composition measurements at Pic du Midi.
We study the influence of the large-scale atmospheric contribution to the dynamics of the convective boundary layer (CBL) in a situation observed during the Boundary Layer Late Afternoon and Sunset ...Turbulence (BLLAST) field campaign. We employ two modeling approaches, the mixed-layer theory and large-eddy simulation (LES), with a complete data set of surface and upper-air atmospheric observations, to quantify the contributions of the advection of heat and moisture, and subsidence. We find that by only taking surface and entrainment fluxes into account, the boundary-layer height is overestimated by 70%. Constrained by surface and upper-air observations, we infer the large-scale vertical motions and horizontal advection of heat and moisture. Our findings show that subsidence has a clear diurnal pattern. Supported by the presence of a nearby mountain range, this pattern suggests that not only synoptic scales exert their influence on the boundary layer, but also mesoscale circulations. LES results show a satisfactory correspondence of the vertical structure of turbulent variables with observations. We also find that when large-scale advection and subsidence are included in the simulation, the values for turbulent kinetic energy are lower than without these large-scale forcings. We conclude that the prototypical CBL is a valid representation of the boundary-layer dynamics near regions characterized by complex topography and small-scale surface heterogeneity, provided that surface- and large-scale forcings are representative for the local boundary layer.
Industrial waste landfills produce great impacts on soil and groundwater. There are many industrial waste landfills in Vale dos Sinos, Southern Brazil, which were inadequately planned and maintained ...since the industry started in the first half of the twentieth century. The largest industrial landfill in the Valley, which causes the most severe impacts on soil and groundwater, is the subject of this paper, which studies the environmental impacts and behavior of contaminants in soil. The landfill was carefully mapped on a scale of 1:1,000; 88 samples were collected from soil probes; the leachate of three samples was comprehensively analyzed; and soils mineralogy and chemistry were studied. Few studies have been made on this landfill. This study shows widespread contamination of soil in the surrounding areas of the landfill. Chromium, chloride and ammonium have the highest contamination levels, reflecting their high contents in landfill leachate. Contamination by petroleum hydrocarbons, cyanide and mercury is registered in more than 65% of soil samples with low concentrations. Lead, copper and barium show low contamination restricted to a few soil samples. Soil contamination occurs mainly in the unsaturated zone of the aquifer at the convergence points of stormwater, showing that the preferential transport of contaminants occurs on surface flow followed by soil infiltration. The results of leaching tests indicate high metal sorption capacity of soil. The remediation of contaminated soil must contain at least the following actions: sealing the top of the landfill, installation of geochemical barriers, removal of the liquid waste basins without sealing the base and collection and treatment of the rainwater drainage.
Apoptosis in Gingival Overgrowth Tissues Kantarci, A.; Augustin, P.; Firatli, E. ...
Journal of dental research,
09/2007, Letnik:
86, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Variations in the balance between cell proliferation and apoptosis could contribute to the etiology of gingival overgrowth. The aim of this study was to test the hypothesis that, in fibrotic gingival ...lesions, fibroblast proliferation is stimulated and apoptosis is decreased. Apoptotic index, caspase 3 expression, the proliferative index, FOXO1 expression, and histological inflammation were measured in situ. Analysis of data showed that apoptosis decreased in all forms of gingival overgrowth examined (p < 0.05), and inflammation caused a small but significant increase compared with non-inflamed tissues (p < 0.05). The greatest decrease of apoptosis occurred in the most fibrotic tissues. Cell proliferation was elevated in all forms of gingival overgrowth tested, independent of inflammation (p < 0.05). To identify potential mechanisms of transcriptional regulation of apoptosis, we assessed FOXO1 and caspase 3 expression levels and found them to correlate well with diminished apoptosis. Analysis of data suggests that increased fibroblast proliferation and a simultaneous decrease in apoptosis contribute to gingival overgrowth.
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