26,927 research outputs found
Targeting the protein-protein interactions of the HIV lifecycle
No full textThe human immunodeficiency virus (HIV), the causative agent of acquired immunodeficiency syndrome (AIDS), relies heavily on protein-protein interactions in almost every step of its lifecycle. Targeting these interactions, especially those between virus and host proteins, is increasingly viewed as an ideal avenue for the design and development of new therapeutics. In this tutorial review, we outline the lifecycle of HIV and describe some of the protein-protein interactions that control and regulate each step of this process, also detailing efforts to develop therapies that target these interactions
Comparison of HYPERION and ALI satellite imagery classification
No full textCelem przeprowadzonych badan było porównanie wyników klasyfikacji obrazów satelitarnych - hiperspektralnych: HYPERION i wielospektralnych: ALI, zarejestrowanych w zakresach spektralnych podobnych do obrazu: LANDSAT. Testy prowadzono na obszarze leżącym na wschód od aglomeracji krakowskiej, dla którego dysponowano obrazami z platformy EO – 1 zarejestrowanymi w 2006 roku, dzięki projektowi KBN (nr 3T 09D 09429). W badaniach wykorzystano oprogramowanie specjalistyczne (ENVI 4.1) dedykowane opracowaniom danych teletedetekcyjnych. Obrazy HYPERION zostały wstępnie przetworzone w celu usunięcia zakłóceń spowodowanych wpływem atmosfery i tzw. efektem „smiling”. Klasyfikacje przeprowadzono tylko metodami tradycyjnie wykorzystywanymi w przetwarzaniu obrazów wielospektralnych, czyli za pomocą klasyfikacji nienadzorowanej i nadzorowanej. Założenie metodyczne porównania wyników klasyfikacji polegało na wykorzystaniu dla obu obrazów tych samych uczących pól treningowych i podobnych pól kontrolnych wykorzystywanych do oceny dokładności. Ponadto wszystkie parametry zastosowanych algorytmów były równie_ identyczne dla obu obrazów. Pola treningowe i testowe wybierano manualnie z wykorzystaniem kompozycji barwnych. W trakcie prowadzenia testów zaistniała konieczność zredukowania liczby analizowanych kanałów obrazu HYPERION, ponieważ w przeciwnym razie nie uzyskiwano zadawalających wyników klasyfikacji. W takim przypadku dokładność klasyfikacji obrazu HYPERION była wyższa ni_ dokładność klasyfikacji obrazu ALI. Natomiast wynik klasyfikacji wszystkich kanałów obrazu HYPERION albo w ogóle był nie do zaakceptowania, albo wynik klasyfikacji był znacznie gorszy ni_ w przypadku ALI i ograniczonej liczby kanałów HYPERION.The main aim of the research was to compare the results of satellite image classification: HYPERION and ALI, recorded in a spectral range similar to LANDSAT. Analyses were performed using the test area to the east of Krakow. Satellite iamges were obtained in 2006 thanks to scientific project KBN (no. 3T 09D 09429). The image processed with ENVI. HYPERION was initially preprocessed to remove so-called atmospheric effects, and so-called “similing” effect. The classification was performed using conventional spectral methods: unsupervised and supervised classification. The background of the comparison was applied in the same training and control area, and the same parameters of classification. Training and control areas ware selected using colour compositions. In the research, a need to reduce the amount of HYPERION channels emerged, otherwise the classification results would not be possible to interpret. In such case, the accuracy of HYPERION channel reduction classification was higher than that of ALI. The result of classification of all HYPERION image channels, however, was either completely unacceptable, or the classification result was much worse than in the case of ALI and limited number of HYPERION channels
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
No full textFirst observations of the B0s
→ψ(2S)η, B0 →ψ(2S)π
+
π
− and B0s
→ψ(2S)π
+
π
− decays are made
using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in
proton–proton collisions at a centre-of-mass energy of
√
s = 7 TeV. The ratios of the branching fractions
of each of the ψ(2S) modes with respect to the corresponding J/ψ decays are
B(B0s
→ψ(2S)η)
÷
B(B0s
→J/ψη)
= 0.83± 0.14 (stat)±0.12 (syst) ±0.02 (B),
;
B(B0→ψ(2S)π
+
π
−
)
÷
B(B0→J/ψπ
+
π
−
)
= 0.56± 0.07 (stat)±0.05 (syst)± 0.01 (B),
;
B(B0s
→ψ(2S)π
+
π
−
)
÷
B(B0s
→J/ψπ
+
π
−
)
= 0.34± 0.04 (stat)±0.03 (syst)± 0.01 (B),
where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/ψ
and ψ(2S) meson decays
Measurement of the isospin asymmetry in B -> K(*) mu+mu- decays
No full textThe isospin asymmetries of B → K (∗) μ + μ − decays and the partial branching fractions of B 0 → K 0 μ + μ − and B + → K ∗+ μ + μ − are measured as a function of the di-muon mass squared q 2 using an integrated luminosity of 1.0 fb−1 collected with the LHCb detector. The B → Kμ + μ − isospin asymmetry integrated over q 2 is negative, deviating from zero with over 4 σ significance. The B → K ∗ μ + μ − decay measurements are consistent with the Standard Model prediction of negligible isospin asymmetry. The observation of the decay B 0 → K S μ + μ − is reported with 5.7 σ significance. Assuming that the branching fraction of B 0 → K 0 μ + μ − is twice that of B 0 → K S μ + μ −, the branching fractions of B 0 → K 0 μ + μ − and B → K ∗+ μ + μ − are found to be (0.31−0.06) × 10−6 and (1.16 ± 0.19) × 10−6, respectively
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Search for the b(b)over-bar decay of the standard model Higgs boson in associated (W/Z)H production with the ATLAS detector
No full textÇetin, Serkant Ali (Dogus Author)A search for the b (b) over bar decay of the Standard Model Higgs boson is performed with the ATLAS experiment using the full dataset recorded at the LHC in Run 1. The integrated luminosities used are 4.7 and 20.3 fb(-1) from pp collisions at root s = 7 and 8 TeV, respectively. The processes considered are associated (WIZ)H production, where W -> e nu/mu nu, Z -> ee/mu mu, and Z -> nu nu. The observed (expected) deviation from the backgroundonly hypothesis corresponds to a significance of 1.4 (2.6) standard deviations and the ratio of the measured signal yield to the Standard Model expectation is found to be mu = 0.52 +/- 0.32 (stat.) +/- 0.24 (syst.) for a Higgs boson mass of 125.36 GeV. The analysis procedure is validated by a measurement of the yield of (W/Z)Z production with Z -> b (b) over bar in the same final states as for the Higgs boson search, from which the ratio of the observed signal yield to the Standard Model expectation is found to be 0.74 +/- 0.09 (stat.) +/- 0.14 (syst.)
Feature composition - towards product lines of event-B models
No full textEvent-B is a formal language for modelling reactive systems, based on set theory and first-order logic. The RODIN toolkit provides comprehensive tool support for modelling and refinement in Event-B, analysis and verification using animator/model-checkers and theorem provers. We consider the need to support reuse, in particular product line reuse, in such a formal development method. Feature modelling is an established technique for reuse in product lines. We introduce concepts of feature modelling and composition in Event-B to support the reuse of formal models and developments. A prototype feature composition tool has been developed (as a RODIN plug-in) for Event-B, based on the Eclipse Modelling Framework (EMF). Using an MDD philosophy, the tool extends the Event-B language meta-model to a composition meta model, and implements prototype composition patterns for Event-B features. Thus, a required composite model can be constructed by selecting, specializing, and composing input features in a defined way. The tool is the first step towards full feature modelling for product line model reuse for Event-B. We describe future work required to meet this goal
Influence of Batch Cooling Crystallization on Mannitol Physical Properties and Drug Dispersion from Dry Powder Inhalers
No full textThis study provides, for the first time, an evaluation of the physicochemical properties of batch cooling crystallized mannitol particles combined with how these properties correlated with the inhalation performance from a dry powder inhaler (Aerolizer). The results showed that the type of polymorph changed from β-form (commercial mannitol) to mixtures of β- + δ-mannitol (cooling crystallized mannitol crystals). In comparison to mannitol particles, crystallized at a higher supersaturation degree, a lower degree of supersaturation favored the formation of mannitol crystals with a more regular and elongated habit, smoother surface, higher specific surface area, higher fine particle content, higher bulk density, and higher tap density. Cooling crystallized mannitol particles demonstrated considerably lower salbutamol sulfate–mannitol adhesion in comparison to commercial mannitol, with a linear reduction as surface roughness decreased and fines content increased. Also, mannitol crystals with smoother surfaces demonstrated a reduction in salbutamol sulfate content uniformity (expressed as %CV) within salbutamol sulfate–mannitol formulations. Despite the different physical properties, all mannitol products showed similar flow properties and similar emission of salbutamol sulfate upon inhalation. However, mannitol crystals grown from lower supersaturation (reduced roughness and increased fines) generated a finer aerodynamic size distribution and consequently deposited higher amounts of salbutamol sulfate on lower stages of the impactor. Regression analysis indicated linear relationships showing higher fine particle fraction of salbutamol sulfate in the case of mannitol particles having a more elongated shape, higher fines content, higher specific surface area, higher bulk density, and higher tap density. In conclusion, a cooling crystallization technique could be controlled to produce mannitol particles with controlled physical properties that could be used to influence aerosolization performance of a dry powder inhaler product
An investigation of factors influencing the spatial and temporal distribution of surface phytoplankton in the English Channel and Bay of Biscay in 2003 and 2004
No full textThroughout 2003 and 2004 continuous autonomous observations of surfacetemperature, conductivity and chlorophyll fluorescence were recorded on the P&O"Pride of Bilbao" ferry between Portsmouth, UK and Bilbao Spain. Different conditionsover the shelf, slope and deep waters along the route were detected and studied - fromeutrophic harbour waters to the southern Bay of Biscay, which is oligotrophic insummer. During the two years, 21 manned crossings on the ferry provided informationon nutrients, phytoplankton biomass and speciation. Measurements include chlorophylla concentrations (calibration of the fluorimeter is discussed), High Performance LiquidChromatography (HPLC) determined pigments concentrations, phytoplankton speciesabundance (biomass and identification) and nutrients. Data was also available fromsatellite images for estimates of chlorophyll (SeaWIFS), zooplankton abundance fromCPR (Continuous Plankton Recorder) tows, wind speed and direction and irradiance.This has enabled phytoplankton populations to be related to-: (1) nutrient supply (2)grazing pressure (3) fresh water influences, (4) hydrography and (5) climatic conditions.The distributions of hydrographic properties and of plankton were analysed on the basisof four generalised regions (i) well-mixed, (ii) northern summer stratified, and (iii)southern summer stratified on the shelf and (iv) oceanic region in the Bay of Biscaywater. There were differences between the two years in the timing of seasonal changesand in the abundance of phytoplankton species. Chlorophyll a values were generallyhigher in shelf waters compared to oceanic water in both years.The spring phytoplankton bloom reached its peak during March 2003 in the Bay ofBiscay and during April on the continental shelf with maximum chlorophyll values of 2-4 mg m-3. Whereas, the strong SW wind in Bay of Biscay in winter 2004 may havedelayed growth in this region. In the shelf regions in 2004 low salinity values offwestern France and high solar irradiance in the north are likely to have led to earlierphytoplankton biomass than in 2003. During early summer, the coccolithophore,Emiliania huxlyei (>1000 cells ml-1) was widespread in northern stratified regions, moreso in 2003 than in 2004. In the summer of 2003 an exceptional dinoflagellate bloomoccurred in the western English Channel. The bloom was composed of a monspecificsurface population of Karenia mikimotoi, giving cell densities up to 8000 cells ml-1 andchlorophyll a concentrations up to 70 mg m-3. Development of this dinoflagellate bloomin the western English Channel could be explained in terms of physical stability, andiilow wind speed together with sufficient light and a supply of inorganic nutrientsfavouring growth of the cells. By contrast, in 2004, the abundance of diatoms washigher than 2003 and K. mikimotoi was common but not at bloom levels (chlorophyll a~4.0 mg m-3). A mixed diatom-dinoflagellate community was the dominant the finalstage in the succession, as the summer thermocline was less well developed. Thephytoplankton biomass and composition in 2003 matches the classical model ofphytoplankton seasonal succession in temperate waters (Margalef, 1978; Smayda, 1980)but this was not obvious in 2004.In general, the FerryBox system on the Pride of Bilbao in 2003 and 2004 was successfuland improved understanding of the relationship between the phytoplankton populationand hydrographic regimes in 2003 and 2004 between Portsmouth and Bilbao.Improvements in future might include continuous observations of oxygen and nutrientsand more work can be done to link FerryBox data, satellite and CPR basedobservations
Search for W ' -> tb decays in the hadronic final state using pp collisions at root s=13 TeV with the ATLAS detector
No full textA search for W'-boson production in the W' -> t (b) over bar -> q (q) over bar 'b (b) over bar decay channel is presented using 36.1 fb(-1) of 13 TeV proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search is interpreted in terms of both a left-handed and a right-handed chiral W' boson within the mass range 1-5 TeV. Identification of the hadronically decaying top quark is performed using jet substructure tagging techniques based on a shower deconstruction algorithm. No significant deviation from the Standard Model prediction is observed and the results are expressed as upper limits on the W' -> t (b) over bar production cross-section times branching ratio as a function of the W'-boson mass. These limits exclude W' bosons with right-handed couplings with masses below 3.0 TeV and W' bosons with left-handed couplings with masses below 2.9 TeV, at the 95% confidence level. (C) 2018 The Author. Published by Elsevier B.V
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