5,631 research outputs found
Oscillating Neutrinos from the Galactic Center
It has recently been demonstrated that the -ray emission spectrum of
the EGRET-identified, central Galactic source 2EG J1746-2852 can be well fitted
by positing that these photons are generated by the decay of 's produced
in p-p scattering at or near an energizing shock. Such scattering also produces
charged pions which decay leptonically.The ratio of -rays to neutrinos
generated by the central Galactic source may be accurately determined and a
well-defined and potentially-measurable high energy neutrino flux at Earth is
unavoidable. An opportunity, therefore, to detect neutrino oscillations over an
unprecedented scale is offered by this source. In this paper we assess the
prospects for such an observation with the generation of neutrino \v{C}erenkov
telescopes now in the planning stage. We determine that the next generation of
detectors may find an oscillation signature in the Galactic Center (GC) signal.Comment: 45 pages, LaTeX, uses ApJ style, some minor revisions, this final
version to be published in ApJ
Comparing the Galactic Bulge and Galactic Disk Millisecond Pulsars
The Galactic Center Excess (GCE) is an extended gamma-ray source in the
central region of the Galaxy found in Fermi Large Area Telescope (Fermi-LAT)
data. One of the leading explanations for the GCE is an unresolved population
of millisecond pulsars (MSPs) in the Galactic bulge. Due to differing star
formation histories it is expected that the MSPs in the Galactic bulge are
older and therefore dimmer than those in the Galactic disk. Additionally,
correlations between the spectral parameters of the MSPs and the spin-down rate
of the corresponding neutron stars have been observed. This implies that the
bulge MSPs may be spectrally different from the disk MSPs. We perform detailed
modelling of the MSPs from formation until observation. Although we confirm the
correlations, we do not find they are sufficiently large to significantly
differentiate the spectra of the bulge MSPs and disk MSPs when the
uncertainties are accounted for. Our results demonstrate that the population of
MSPs that can explain the gamma-ray signal from the resolved MSPs in the
Galactic disk and the unresolved MSPs in the boxy bulge and nuclear bulge can
consistently be described as arising from a common evolutionary trajectory for
some subset of astrophysical sources common to all these different
environments. We do not require that there is anything unusual about inner
Galaxy MSPs to explain the GCE. Additionally, we use a more accurate geometry
for the distribution of bulge MSPs and incorporate dispersion measure estimates
of the MSPs' distances. We find that the elongated boxy bulge morphology means
that some the bulge MSPs are closer to us and so easier to resolve. We identify
three resolved MSPs that have significant probabilities of belonging to the
bulge population.Comment: 37 pages, 20 figures, V3: Minor grammatical
corrections/clarifications. Reflects version to appear in JCAP. V4: Minor
typos correcte
Pathogenesis-Related Proteins in Wine and White Wine Protein Stabilization
Protein stabilisation in white wine is of great concern to winemakers as denaturation of wine proteins may cause haze formation, which is usually considered a wine fault. Pathogenesis-related (PR) proteins derived from grapes are the major soluble proteins remaining in the finished wine, which are mainly responsible for haze formation. The development of PR proteins in grapes during ripening and the extraction of PR proteins from grapes into juice can largely affect the concentration of PR proteins in the final wine, which consequently influence wine protein stability. Bentonite fining is the most common method to remove proteins in white wine before bottling, but it can cause the loss of wine volume and the removal of beneficial aromas. Thus, a number of alternative methods have been proposed for their potential to replace bentonite fining
Effect of a national primary care pay for performance scheme on emergency hospital admissions for ambulatory care sensitive conditions: controlled longitudinal study.
OBJECTIVE: To estimate the impact of a national primary care pay for performance scheme, the Quality and Outcomes Framework in England, on emergency hospital admissions for ambulatory care sensitive conditions (ACSCs).
DESIGN: Controlled longitudinal study.
SETTING: English National Health Service between 1998/99 and 2010/11.
PARTICIPANTS: Populations registered with each of 6975 family practices in England.
MAIN OUTCOME MEASURES: Year specific differences between trend adjusted emergency hospital admission rates for incentivised ACSCs before and after the introduction of the Quality and Outcomes Framework scheme and two comparators: non-incentivised ACSCs and non-ACSCs.
RESULTS: Incentivised ACSC admissions showed a relative reduction of 2.7% (95% confidence interval 1.6% to 3.8%) in the first year of the Quality and Outcomes Framework compared with ACSCs that were not incentivised. This increased to a relative reduction of 8.0% (6.9% to 9.1%) in 2010/11. Compared with conditions that are not regarded as being influenced by the quality of ambulatory care (non-ACSCs), incentivised ACSCs also showed a relative reduction in rates of emergency admissions of 2.8% (2.0% to 3.6%) in the first year increasing to 10.9% (10.1% to 11.7%) by 2010/11.
CONCLUSIONS: The introduction of a major national pay for performance scheme for primary care in England was associated with a decrease in emergency admissions for incentivised conditions compared with conditions that were not incentivised. Contemporaneous health service changes seem unlikely to have caused the sharp change in the trajectory of incentivised ACSC admissions immediately after the introduction of the Quality and Outcomes Framework. The decrease seems larger than would be expected from the changes in the process measures that were incentivised, suggesting that the pay for performance scheme may have had impacts on quality of care beyond the directly incentivised activities
Effect of a national primary care pay for performance scheme on emergency hospital admissions for ambulatory care sensitive conditions: controlled longitudinal study.
OBJECTIVE: To estimate the impact of a national primary care pay for performance scheme, the Quality and Outcomes Framework in England, on emergency hospital admissions for ambulatory care sensitive conditions (ACSCs). DESIGN: Controlled longitudinal study. SETTING: English National Health Service between 1998/99 and 2010/11. PARTICIPANTS: Populations registered with each of 6975 family practices in England. MAIN OUTCOME MEASURES: Year specific differences between trend adjusted emergency hospital admission rates for incentivised ACSCs before and after the introduction of the Quality and Outcomes Framework scheme and two comparators: non-incentivised ACSCs and non-ACSCs. RESULTS: Incentivised ACSC admissions showed a relative reduction of 2.7% (95% confidence interval 1.6% to 3.8%) in the first year of the Quality and Outcomes Framework compared with ACSCs that were not incentivised. This increased to a relative reduction of 8.0% (6.9% to 9.1%) in 2010/11. Compared with conditions that are not regarded as being influenced by the quality of ambulatory care (non-ACSCs), incentivised ACSCs also showed a relative reduction in rates of emergency admissions of 2.8% (2.0% to 3.6%) in the first year increasing to 10.9% (10.1% to 11.7%) by 2010/11. CONCLUSIONS: The introduction of a major national pay for performance scheme for primary care in England was associated with a decrease in emergency admissions for incentivised conditions compared with conditions that were not incentivised. Contemporaneous health service changes seem unlikely to have caused the sharp change in the trajectory of incentivised ACSC admissions immediately after the introduction of the Quality and Outcomes Framework. The decrease seems larger than would be expected from the changes in the process measures that were incentivised, suggesting that the pay for performance scheme may have had impacts on quality of care beyond the directly incentivised activities
Interactions of Vitis vinifera L. cv. Pinot Noir grape anthocyanins with seed proanthocyanidins and their effect on wine color and phenolic composition
The initial concentration of anthocyanin and proanthocyanidin in wine affects the development of SO₂-resistant pigments, as well as color and non-color contributing polymeric fractions. However, the effect of extracted monomeric Pinot Noir (Vitis vinifera L. cv.) grape anthocyanins with seed proanthocyanidins are poorly studied. In model ferments, the reaction of purified Vitis vinifera L. cv. Pinot noir monomeric anthocyanins with seed proanthocyanidins extract were investigated at high and low concentrations of each reactant. During wine aging, monomeric anthocyanins decreased whereas SO₂-resistant pigments increased. Higher anthocyanin concentrations retained more soluble tannins in model ferments during aging, while those with higher anthocyanin and lower proanthocyanidin concentrations had the highest MCP-tannin concentration in model ferments. HPLC analysis showed that the color contributing polymeric fractions are dependent upon the initial concentration of anthocyanin/proanthocyanidin ratios and more inclined towards high anthocyanin/low proanthocyanidin concentrations. Wine color parameters were measured in the form of L*, a*, b*, C (chroma) and H (hue) values and showed a decrease in hue and chroma in model wines after aging. The color data supported the HPLC findings that the initial anthocyanin/proanthocyanidin ratio was critical for the establishment of a color contributing polymeric fractions and stable deep red color in wines
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