1,028 research outputs found
Effect of Milk Yield, Sward Height and Concentrate Supplementation Level on Herbage Intake and Grazing Behaviour of Set-Stocked Dairy Cattle in Spring
An experiment was carried out in spring over 42 days, with 48 multiparous Holstein Friesian cows, to examine the interrelationship of milk yield level, sward height and concentrate level. Two initial milk yield groups of 21.3 and 35.5 kg/day, two range of compressed sward heights of 3 to 5 cm, and 7 to 9 cm , and three concentrate levels of 0 and 6 kg/day and ad libitum were evaluated in a factorial design. Multiple regression analyses were carried out relating intake and behavioural dependent variables to the independent variables initial milk yield (IMY), sward height (SH) and concentrate intake (CI).Total DM intake was highest for the high yielding group (P\u3c0.001) (16.4 and 19.6 s.e.d 0.65), and rate of intake (g DM/min) was higher (P\u3c0.001) (21.8 and 27.9 s.e.d. 1.91). Concentrates reduced rate of intake ( 31.4, 25.8, and 20.7 g DM/min s.e.d. 2.34). The multiple regression coefficients indicated that the herbage intake increased by 0.61 kg/day per 1 cm increase in sward height, reduced by 0.69 kg/day per kg increase in concentrate, and increased by 0.21 kg/day per kg increase in initial milk yield
Influence of Giving a Choice of Grazing or Maize Silage Offered in the Field Simultaneously on Diet Selection of Lactating Dairy Cows
Changing the times of access to grazing and to maize silage (MS) offered indoors affects the relative intake of each feed, but has little effect on dairy cow performance (Hernandez-Mendo & Leaver, 2000). Offering the MS in the grazing paddock as an instantaneous alternative to grazing should give an insight into the factors influencing feed intake, and may provide a means of alleviating the high rate of decline in milk yield of grazing dairy cows. The objective of this study was to examine the response in diet preferences and performance of lactating dairy cows when grazing a perennial ryegrass sward and having access to maize silage ad libitum simultaneously in spring, at two concentrate levels (CL) and two sward heights (SH)
The management of common recurrent headaches by chiropractors: A descriptive analysis of a nationally representative survey
© 2018 The Author(s). Background: Headache management is common within chiropractic clinical settings; however, little is yet known about how this provider group manage headache sufferers. The aim of this study is to report on the prevalence of headache patients found within routine chiropractic practice and to assess how chiropractors approach key aspects of headache management applicable to primary care settings. Methods: A 31-item cross-sectional survey was distributed to a national sample of chiropractors (n = 1050) to report on practitioner approach to headache diagnosis, interdisciplinary collaboration, treatment and outcome assessment of headache patients who present with recurrent headache disorders. Results: The survey attracted a response rate of 36% (n = 381). One in five new patients present to chiropractors with a chief complaint of headache. The majority of chiropractors provide headache diagnosis for common primary (84.6%) and secondary (90.4%) headaches using formal headache classification criteria. Interdisciplinary referral for headache management was most often with CAM providers followed by GPs. Advice on headache triggers, stress management, spinal manipulation, soft tissue therapies and prescriptive neck exercises were the most common therapeutic approaches to headache management. Conclusion: Headache patients make up a substantial proportion of chiropractic caseload. The majority of chiropractors managing headache engage in headache diagnosis and interdisciplinary patient management. More research information is needed to understand the headache types and level of headache chronicity and disability common to chiropractic patient populations to further assess the healthcare needs of this patient population
Massive scalar field quasi-normal modes of higher dimensional black holes
We study quasinormal spectrum of massive scalar field in the -dimensional
black hole background. We found the qualitatively different dependence on the
field mass of the fundamental modes for . The behaviour of higher modes
is qualitatively the same for all . Thus for some particular values of mass
(of the field and of the black hole) the spectrum has two dominating
oscillations with a very long lifetime. Also we show that the asymptotically
high overtones do not depend on the field mass. In addition, we present the
generalisation of the Nollert improvement of the continued fraction technique
for the numerical calculation of quasi-normal frequencies of -dimensional
black holes.Comment: 8 pages, 4 figures, misprints corrected, version to appear in Phys.
Rev.
Selection Rules for Black-Hole Quantum Transitions
We suggest that quantum transitions of black holes comply with selection
rules, analogous to those of atomic spectroscopy. In order to identify such
rules, we apply Bohr's correspondence principle to the quasinormal ringing
frequencies of black holes. In this context, classical ringing frequencies with
an asymptotically vanishing real part \omega_R correspond to virtual quanta,
and may thus be interpreted as forbidden quantum transitions. With this
motivation, we calculate the quasinormal spectrum of neutrino fields in
spherically symmetric black-hole spacetimes. It is shown that \omega_R->0 for
these resonances, suggesting that the corresponding fermionic transitions are
quantum mechanically forbidden.Comment: 4 pages, 2 figure
The treatment of migraine patients within chiropractic: Analysis of a nationally representative survey of 1869 chiropractors
© 2017 The Author(s). Background: While the clinical role of manual therapies in migraine management is unclear, the use of chiropractors for this condition is considerable. The aim of this study is to evaluate the prevalence and characteristics of chiropractors who frequently manage patients with migraine. Methods: A national cross-sectional survey of chiropractors collected information on practitioner characteristics, clinical management characteristics and practice settings. A secondary analysis was conducted on 1869 respondents who reported on their migraine caseload to determine the predictors associated with the frequent management of patients with migraine. Results: A large proportion of chiropractors report having a high migraine caseload (HMC) (n = 990; 53.0%). The strongest factors predicting a chiropractor having a HMC include the frequent treatment of patients with axial neck pain (OR = 2.89; 95%CI: 1.18, 7.07), thoracic pain (referred/radicular) (OR = 2.52; 95%CI: 1.58, 3.21) and non-musculoskeletal disorders (OR = 3.06; 95%CI: 2.13, 4.39). Conclusions: Several practice-setting and clinical management characteristics are associated with chiropractors managing a HMC. These findings raise key questions about the therapeutic approach to chiropractic migraine management that deserves further examination. There is a need for more primary research to assess the approach to headache and migraine management provided by chiropractors and to understand the prevalence, burden and comorbidities associated with migraine found within chiropractic patient populations. This information is vital in helping to inform safe, effective and coordinated care for migraine sufferers within the wider health system
Quasi-Normal Modes of Brane-Localised Standard Model Fields II: Kerr Black Holes
This paper presents a comprehensive study of the fundamental quasinormal
modes of all Standard Model fields propagating on a brane embedded in a
higher-dimensional rotating black hole spacetime. The equations of motion for
fields with spin and 1 propagating in the induced-on-the-brane
background are solved numerically, and the dependence of their QN spectra on
the black hole angular momentum and dimensionality of spacetime is
investigated. It is found that the brane-localised field perturbations are
longer-lived when the higher-dimensional black hole rotates faster, while an
increase in the number of transverse-to-the-brane dimensions reduces their
lifetime. Finally, the quality factor , that determines the best oscillator
among the different field perturbations, is investigated and found to depend on
properties of both the particular field studied (spin, multipole numbers) and
the gravitational background (dimensionality, black hole angular momentum
number).Comment: 12 pages, 8 figures, typos corrected, version to appear in Phys. Rev.
Numerical evolutions of a black hole-neutron star system in full General Relativity: I. Head-on collision
We present the first simulations in full General Relativity of the head-on
collision between a neutron star and a black hole of comparable mass. These
simulations are performed through the solution of the Einstein equations
combined with an accurate solution of the relativistic hydrodynamics equations
via high-resolution shock-capturing techniques. The initial data is obtained by
following the York-Lichnerowicz conformal decomposition with the assumption of
time symmetry. Unlike other relativistic studies of such systems, no limitation
is set for the mass ratio between the black hole and the neutron star, nor on
the position of the black hole, whose apparent horizon is entirely contained
within the computational domain. The latter extends over ~400M and is covered
with six levels of fixed mesh refinement. Concentrating on a prototypical
binary system with mass ratio ~6, we find that although a tidal deformation is
evident the neutron star is accreted promptly and entirely into the black hole.
While the collision is completed before ~300M, the evolution is carried over up
to ~1700M, thus providing time for the extraction of the gravitational-wave
signal produced and allowing for a first estimate of the radiative efficiency
of processes of this type.Comment: 16 pages, 12 figure
Quasinormal Modes, the Area Spectrum, and Black Hole Entropy
The results of canonical quantum gravity concerning geometric operators and
black hole entropy are beset by an ambiguity labelled by the Immirzi parameter.
We use a result from classical gravity concerning the quasinormal mode spectrum
of a black hole to fix this parameter in a new way. As a result we arrive at
the Bekenstein - Hawking expression of for the entropy of a black
hole and in addition see an indication that the appropriate gauge group of
quantum gravity is SO(3) and not its covering group SU(2).Comment: 4 pages, 2 figure
Operation of EMEP ‘supersites’ in the United Kingdom. Annual report for 2008.
As part of its commitment to the UN-ECE Convention on Long-range Transboundary Air Pollution the United Kingdom operates two ‘supersites’ reporting data to the Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP).
This report provides the annual summary for 2008, the second full calendar year of operation of the first EMEP ‘supersite’ to be established in the United Kingdom. Detailed operational reports have been submitted to Defra every 3 months, with unratified data. This annual report contains a summary of the ratified data for 2008.
The EMEP ‘supersite’ is located in central southern Scotland at Auchencorth (3.2oW, 55.8oN), a remote rural moorland site ~20 km south-west of Edinburgh. Monitoring operations started formally on 1 June 2006.
In addition to measurements made specifically under this contract, the Centre for Ecology & Hydrology also acts as local site operator for measurements made under other UK monitoring networks: the Automated Urban and Rural Network (AURN), the UK Eutrophication and Acidification Network (UKEAP), the UK Hydrocarbons Network, and the UK Heavy Metals Rural Network. Some measurements were also made under the auspices of the ‘Air Pollution Deposition Processes’ contract. All these associated networks are funded by Defra.
This report summarises the measurements made between January and December 2008, and presents summary statistics on average concentrations.
The site is dominated by winds from the south-west, but wind direction data highlight potential sources of airborne pollutants (power stations, conurbations).
The average diurnal patterns of gases and particles are consistent with those expected for a remote rural site.
The frequency distributions are presented for data where there was good data capture throughout the whole period. Some components (e.g. black carbon) show log-normal frequency distributions, while other components (e.g. ozone) have more nearly normal frequency distributions.
A case study is presented for a period in June 2008, showing the influence of regional air pollutants at this remote rural site.
All the data reported under the contract are shown graphically in the Appendix
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