61,263 research outputs found
Is rapid adaptive evolution important in successful invasions?
No full textEleanor E. Dormontt, Andrew J. Lowe and Peter J. Prenti
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
Full text linkFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied 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 sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
DNA barcoding of invasive species
No full textHugh B. Cross, Andrew J. Lowe and C. Frederico D. Gurgelhttp://trove.nla.gov.au/work/3781057
Lifecourse social position and D-dimer; findings from the 1958 British birth cohort
Full text linkThe aim is to examine the association of lifecourse socioeconomic position (SEP) on circulating levels of D-dimer. Data from the 1958 British birth cohort were used, social class was determined at three stages of respondents' life: at birth, at 23 and at 42 years. A cumulative indicator score of SEP (CIS) was calculated ranging from 0 (always in the highest social class) to 9 (always in the lowest social class). In men and women, associations were observed between CIS and D-dimer (P<0.05). Thus, the respondents in more disadvantaged social classes had elevated levels of D-dimer compared to respondents in less disadvantaged social class. In multivariate analyses, the association of disadvantaged social position with D-dimer was largely explained by fibrinogen, C-reactive protein and von Willebrand Factor in women, and additionally by smoking, alcohol consumption and physical activity in men. Socioeconomic circumstances across the lifecourse at various stages also contribute independently to raised levels of D-dimer in middle age in women only. Risk exposure related to SEP accumulates across life and contributes to raised levels of D-dimer. The association of haemostatic markers and social differences in health may be mediated by inflammatory and other markers
Study of the cell biological role of Lowe Syndrome protein OCRL1
No full textOculocerebrorenal syndrome of Lowe (OCRL) is caused by mutations in a
phosphatidylinositol 5-phosphatase, OCRL1, and is believed to lead to an
elevation of its preferred substrate, PI(4,5)P2. To date, much of the work on
OCRL1 has centred on its role at Golgi and endosomal membranes.
However, there is also evidence of plasma membrane activity for OCRL1,
where its PI(4,5)P2 substrate is known to be highly abundant. PI(4,5)P2
regulates a wide array of downstream cellular functions such as cytoskeletal
dynamics, membrane trafficking and signalling. The tight regulation of
PI(4,5)P2 levels and localisation, like other phosphoinositides, provides a
framework upon which many of these cellular processes work. In this thesis,
effects of OCRL1 loss have been tested through siRNA depletion of OCRL1,
focussing where possible on multiple PI(4,5)P2-dependent mechanisms, and
also focussing on cells forming polarised epithelia. Firstly, we have visualised
the localisation of PI(4,5)P2 in living HeLa cells lacking OCRL1 through
immunostaining for Annexin A2, which showed a marked translocation to the
plasma membrane. This change in distribution of Annexin A2 suggested that
OCRL1 depletion may have an effect on intracellular calcium dynamics as
well as PI(4,5)P2 localisation. We also used a GFP-chimera of the well
characterised PI(4,5)P2-binding pleckstrin homology domain of PLCδ1. This
showed no difference in localisation upon OCRL1 depletion. As OCRL1 is
highly enriched at the TGN, we fused the pleckstrin homology domain of
PLCδ1 to a mutated pleckstrin homology domain of OSBP known to bind ARF1 at the TGN, to act as a coincidence detector for PI(4,5)P2 at the TGN.
This construct also showed no reproducible effect of OCRL1 depletion.
Secondly we tested the effect of loss of OCRL1 on cytosolic calcium levels.
Using two phospholipase C (PLC) agonists, and a SERCA pump inhibitor, we
found no consistent differences in calcium handling upon depletion of OCRL1.
Thirdly, we have assessed the potential specialised role that OCRL1 has in
polarised epithelial cells, which might relate to the clinical picture in Lowe
Syndrome. We found that OCRL1 targets the tight junctions of immortalised
lines and primary cells. Through co-immunoprecipitation, we found OCRL1 in
complexes with the tight junction scaffold protein ZO-1. Most significantly, we
found that depletion of OCRL1 in human polarised epithelial cell lines
interfered with epithelial differentiation, reducing cell number and altering
morphology, to produce large flat cells. We attribute this phenotype, stronger
than any other so far described experimentally, to a defect in tight junction
maturation
Measurement of the B0–B0 oscillation frequency Δmd with the decays B0→D−π+ and B0→ J/ψK∗0
Full text linkThe B
0
–B
0
oscillation frequency Δmd is measured by the LHCb experiment using a dataset corresponding
to an integrated luminosity of 1.0 fb−1
of proton–proton collisions at √
s = 7 TeV, and is found to be
Δmd
=0.5156±0.0051 (stat.)±0.0033 (syst.) ps−1
. The measurement is based on results from analyses
of the decays B
0
→ D
−π
+ (D
−
→ K
+π
−π
−) and B
0
→ J/ψK
∗0
(J/ψ →μ
+μ
−,K
∗0
→ K
+π
−) and
their charge conjugated modes
Search for the rare decays J/y -> D-s(-) rho(+) and J/psi -> <(D)over bar(0)<(K)over bar*(0)
No full textA search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> D-S(-)rho(+) + c.c.) <1.3 x 10(-5) and beta(J/psi -
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
George Lowe and Dr. C. Q. Lynd
No full textPhotograph of Dr. J. Q. Lynd, Agronomy Department, Oklahoma A & M College (left) and George Lowe, WUC McAlester, OK (right) inspecting Bermuda grass on the Dowdy and Clauswitz Farm
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