2,361 research outputs found
Letter: Faecal volatile organic metabolites, promising biomarkers in inflammatory bowel disease and Letter: Faecal volatile organic metabolites as novel diagnostic biomarkers in inflammatory bowel disease. Authors' reply
The aetiology of inflammatory bowel disease (IBD) remains poorly understood. Recent evidence suggests an important role of gut microbial dysbiosis in IBD, and this may be associated with changes in faecal volatile organic metabolites (VOMs).To describe the changes in the faecal VOMs of patients with IBD and establish their diagnostic potential as non-invasive biomarkers.Faecal samples were obtained from 117 people with Crohn's disease (CD), 100 with ulcerative colitis (UC), and 109 healthy controls. Faecal VOMs were extracted using solid-phase micro-extraction and analysed by gas chromatography mass spectrometry. Data analysis was carried out using partial least squares-discriminate analysis (PLS-DA) to determine class membership based on distinct metabolomic profiles.The PLS-DA model showed clear separation of active CD from inactive disease and healthy controls (P < 0.001). Heptanal, 1-octen-3-ol, 2-piperidinone and 6-methyl-2-heptanone were up-regulated in the active CD group [variable important in projection (VIP) score 2.8, 2.7, 2.6 and 2.4, respectively], while methanethiol, 3-methyl-phenol, short-chain fatty acids and ester derivatives were found to be less abundant (VIP score of 3.5, 2.6, 1.5 and 1.2, respectively). The PLS-DA model also separated patients with small bowel CD from healthy controls and those with colonic CD from UC (P < 0.001). In contrast, less distinct separation was observed between active UC, inactive UC and healthy controls.Analysis of faecal volatile organic metabolites can provide an understanding of gut metabolomic changes in IBD. It has the potential to provide a non-invasive means of diagnosing IBD, and can differentiate between UC and CD
âEthnic groupâ, the state and the politics of representation
The assertion, even if only by implication, that âethnic groupâ categories represent ârealâ tangible entities, indeed identities, is commonplace not only in the realms of political and policy discourse but also amongst contemporary social scientists. This paper, following Brubaker (2002), questions this position in a number of key respects: of these three issues will dominate the discussion that follows.
First, there is an interrogation of the proposition that those to whom the categories/labels refer constitute sociologically meaningful âgroupsâ as distinct from (mere) human collectivities. Secondly, there is the question of how these categories emerge, i.e. exactly what series of events, negotiations and contestations lie behind their construction and social acceptance. Thirdly, and as a corollary to the latter point, we explore the process of reification that leads to these categories being seen to represent âreal things in the worldâ (ibid.)
Razvojni prospekti bankarstva u novim i buduÄim zemljama Älanicama EU
Bank consolidation has substantially decreased the number of banks in European banking, which has had important implications for the banking sectors structure in all EU member countries. The consolidation processes have had a tremendous impact on the developments in banking sectors of new EU member countries, where
major structural changes have been initiated mostly by new entrant banks from the old EU member countries. The future banking development in new EU member countries will very likely follow some main patterns known from the old EU members. Rather speculative conjectures, which are based on a comparison with banking sectors in other EU member countries indicate, that the total-asset-to-GDP
ratio in new member countries should further improve in the future. The banking sector growth will be based mostly on the growth of the credit to non-banking sector, while banks are not expected anymore to use non-bank deposits as a predominant way of funding. Instead potentials for alternative funding possibilities should be activated. Although the non-bank financial intermediaries in new EU members
represent a serious competition to banks, their relative underdevelopment prevents them from impacting the developments in banking sectors as known from old EU member countries.Konsolidacija banaka znatno je smanjila broj banaka u europskom bankarstvu, ĆĄto ima znaÄajne implikacije na bankarski sektor u svim zemljama Älanicama EU. Konsolidacija banaka imala je veliki utjecaj na razvoj bankarskog sektora svih novih zemalja Älanica, gdje su najveÄe strukturalne promjene inicirane stvaranjem novih banaka uz sudioniĆĄtvo starih Älanica EU. BuduÄi bankarski razvoj u novim zemljama Älanicama EU vjerojatno Äe se temeljiti na onom starih Älanica. ViĆĄe spekulativna nagaÄanja, koja se temelje na usporedbi s bankarskim sektorima u drugim zemljama Älanicama, pokazuju da Äe se odnos kapitala prema BDP u novim zemljama Älanicama poveÄavati u buduÄnosti. Rast bankarskog sektora temeljit Äe se veÄim dijelom na rastu zajmova nebankarskim sektorima, a od banaka se oÄekuje da viĆĄe ne rabe nebankarske depozite kao glavni oblik financiranja. Umjesto toga, trebaju se aktivirati moguÄnosti za alternativnim financiranjem. Nebankarski financijski posrednici u novim zemljama Älanicama EU bankama predstavljaju ozbiljnu konkurenciju, meÄutim, njihova relativna nerazvijenost spreÄava ih da utjeÄu na razvoj u bankarskom sektoru kao ĆĄto je to bio sluÄaj u starim zemljama Älanicama EU
Peaks in the Hartle-Hawking Wave Function from Sums over Topologies
Recent developments in ``Einstein Dehn filling'' allow the construction of
infinitely many Einstein manifolds that have different topologies but are
geometrically close to each other. Using these results, we show that for many
spatial topologies, the Hartle-Hawking wave function for a spacetime with a
negative cosmological constant develops sharp peaks at certain calculable
geometries. The peaks we find are all centered on spatial metrics of constant
negative curvature, suggesting a new mechanism for obtaining local homogeneity
in quantum cosmology.Comment: 16 pages,LaTeX, no figures; v2: some changes coming from revision of
a math reference: wave function peaks sharp but not infinite; v3: added
paragraph in intro on interpretation of wave functio
A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7
Circinus X-1 is a bright and highly variable X-ray binary which displays
strong and rapid evolution in all wavebands. Radio flaring, associated with the
production of a relativistic jet, occurs periodically on a ~17-day timescale. A
longer-term envelope modulates the peak radio fluxes in flares, ranging from
peaks in excess of a Jansky in the 1970s to an historic low of milliJanskys
during the years 1994 to 2007. Here we report first observations of this source
with the MeerKAT test array, KAT-7, part of the pathfinder development for the
African dish component of the Square Kilometre Array (SKA), demonstrating
successful scientific operation for variable and transient sources with the
test array. The KAT-7 observations at 1.9 GHz during the period 13 December
2011 to 16 January 2012 reveal in temporal detail the return to the
Jansky-level events observed in the 1970s. We compare these data to
contemporaneous single-dish measurements at 4.8 and 8.5 GHz with the HartRAO
26-m telescope and X-ray monitoring from MAXI. We discuss whether the overall
modulation and recent dramatic brightening is likely to be due to an increase
in the power of the jet due to changes in accretion rate or changing Doppler
boosting associated with a varying angle to the line of sight.Comment: 7 pages, 5 figures, accepted for publication in MNRAS 14 May 201
Geometric Finiteness, Holography and Quasinormal Modes for the Warped AdS_3 Black Hole
We show that there exists a precise kinematical notion of holography for the
Euclidean warped black hole. This follows from the fact that the
Euclidean warped black hole spacetime is a geometrically finite
hyperbolic manifold. For such manifolds a theorem of Sullivan provides a
one-to-one correspondence between the hyperbolic structure in the bulk and the
conformal structure of its boundary. Using this theorem we obtain the
holographic quasinormal modes for the warped black hole.Comment: Latex file, 7 pages. Journal versio
Can the polarization of the strange quarks in the proton be positive ?
Recently, the HERMES Collaboration at DESY, using a leading order QCD
analysis of their data on semi-inclusive deep inelastic production of charged
hadrons, reported a marginally positive polarization for the strange quarks in
the proton. We argue that a non-negative polarization is almost impossible.Comment: 6 pages, latex, minor changes in the discussion after Eq. (9
A comparison of weak-turbulence and PIC simulations of weak electron-beam plasma interaction
Quasilinear theory has long been used to treat the problem of a weak electron
beam interacting with plasma and generating Langmuir waves. Its extension to
weak-turbulence theory treats resonant interactions of these Langmuir waves
with other plasma wave modes, in particular ion-sound waves. These are strongly
damped in plasma of equal ion and electron temperatures, as sometimes seen in,
for example, the solar corona and wind. Weak turbulence theory is derived in
the weak damping limit, with a term describing ion-sound wave damping then
added. In this paper we use the EPOCH particle-in-cell code to numerically test
weak turbulence theory for a range of electron-ion temperature ratios. We find
that in the cold ion limit the results agree well, but increasing ion
temperature the three-wave resonance becomes broadened in proportion to the
ion-sound wave damping rate. This may be important in, for example, the theory
of solar radio bursts, where the spectrum of Langmuir waves is critical.
Additionally we establish lower limits on the number of simulation particles
needed to accurately reproduce the electron and wave distributions in their
saturated states, and to reproduce their intermediate states and time
evolution.Comment: Accepted by PO
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