1,437 research outputs found
Evaluation of milk yield losses associated with Salmonella antibodies in bulk-tank milk in bovine dairy herds
The effect of Salmonella on milk production is not well established in cattle. The objective of this study was to investigate whether introduction of Salmonella into dairy cattle herds was associated with reduced milk yield and the duration of any effect. Longitudinal data from 2005 through 2009 were used, with data from 12 months before until 18 months after the estimated date of infection. Twenty-eight case herds were selected based on an increase in the level of Salmonella specific antibodies in bulk-tank milk from < 10 corrected optic density percentage (ODC%) to â„ 70 ODC% between two consecutive 3-monthly measurements in the Danish Salmonella surveillance program. All selected case herds were conventional Danish Holstein herds. Control herds (n = 40) were selected randomly from Danish Holstein herds with Salmonella antibody levels consistently < 10
ODC%. A date of herd infection was randomly allocated to the control herds. Hierarchical mixed effect models with the outcome test day energy corrected milk yield (ECM)/cow were used to investigate the daily milk yield before and after the estimated herd infection date for cows in parity 1, 2 and 3+. Control herds were used to evaluate whether the effects in the case herds could be reproduced in herds without Salmonella infection. Herd size, days in milk, somatic cell count, season, and year were included in the models. The key results were that first parity cow yield was reduced by a mean of 1.4 kg (95% CI: 0.5 to 2.3) ECM/cow per day from seven to 15 months after the estimated herd infection date, compared with first parity cows in the same herds in the 12 months before the estimated herd infection date. Yield for parity 3+ was reduced by a mean of 3.0 kg (95% CI: 1.3 to 4.8) ECM/cow per day from seven to 15 months after herd infection compared with parity 3+ cows in the 12 months before the estimated herd infection. There were minor differences in yield in second parity cows before and after herd infection, and no difference between cows in control herds before and after the simulated infection date. There was a significant drop in milk yield in affected herds and the reduction was detectable several months after the increase in bulk-tank milk Salmonella antibodies. It took more than a year for milk yield to return to pre- infection levels
BioConcens: Biomass and bioenergy production agriculture â consequences for soil fertility, environment, spread of animal parasites and socio-economy
The research programme called âinternational research cooperation and organic integrityâ was commenced for a period 2006-2010. It is coordinated by DARCOF (The Danish Research Centre for Organic Farming). The whole programme, with acronym DARCOF III, consists of 15 projects (http://www.darcof.dk/research/darcofiii/index.html). One of them is BIOCONCENS - Biomass and bioenergy production in organic farming â consequences for soil fertility, environment, spread of animal parasites and socio-economy (http://www.bioconcens.elr.dk/uk/). The production of bioenergy in organic agriculture (OA) can reduce its dependency of fossil fuels and decrease green house gasses emission; consequently it will increase sustainability of organic farms. Biorefinery concept based on co-production of biogas, bioethanol and protein fodder in organic farming will be developed within the BIOCONCENS project and the background for the project and the different work packages will be presented in this paper
Hemp raw materials: The effect of cultivar, growth conditions and pretreatment on the chemical composition of the fibres
Sward structure measurements to monitor the effect of grazing in nature management situations
In Denmark private farmers under contract with the society manage many nature conservation areas on low-lying organic soil. In the contract the grazing system is poorly difined in relation to the goals and there is a lack of monitoring intruments for practical use in natural areas. Thus there is a need to define grazing system indicators, which should make it possible toevaluate effect from grazing and provide a feed-back to the goals. To describe the effect of grazing on the vegetation structure, detailed measurements of sward heights, species composition, species phenology, distance to flowering speecimens of Juncus effeusus I. or J. conglomeratus I. were carried out in paddocks grazed by 1st year steers at two different levels of plant species diversity and at two levels of grazing intensity. The aim was to identify variables able to ecpose the effect of the different treatments
Order from disorder in lattice QCD at high density
We investigate the properties of the ground state of strong coupling lattice
QCD at finite density. Our starting point is the effective Hamiltonian for
color singlet objects, which looks at lowest order as an antiferromagnet, and
describes meson physics with a fixed baryon number background. We concentrate
on uniform baryon number backgrounds (with the same baryon number on all
sites), for which the ground state was extracted in an earlier work, and
calculate the dispersion relations of the excitations. Two types of Goldstone
boson emerge. The first, antiferromagnetic spin waves, obey a linear dispersion
relation. The others, ferromagnetic magnons, have energies that are quadratic
in their momentum. These energies emerge only when fluctuations around the
large-N_c ground state are taken into account, along the lines of ``order from
disorder'' in frustrated magnetic systems. Unlike other spectrum calculations
in order from disorder, we employ the Euclidean path integral. For comparison,
we also present a Hamiltonian calculation using a generalized
Holstein-Primakoff transformation. The latter can only be constructed for a
subset of the cases we consider.Comment: 24 pages, 6 figures, 1 tabl
Historical TOC concentration minima during peak sulfur deposition in two Swedish lakes
International audienceDecadal-scale variations in total organic carbon (TOC) concentration in lake water since AD 1200 in two small lakes in southern Sweden were reconstructed based on visibleânear-infrared spectroscopy (VNIRS) of their recent sediment successions. In order to assess the impacts of local land-use changes, regional variations in sulfur, and nitrogen deposition and climate variations on the inferred changes in TOC concentration, the same sediment records were subjected to multi-proxy palaeolimnological analyses. Changes in lake-water pH were inferred from diatom analysis , whereas pollen-based land-use reconstructions (Landscape Reconstruction Algorithm) together with geochemical records provided information on catchment-scale environmental changes, and comparisons were made with available records of climate and population density. Our long-term reconstructions reveal that inferred lake-water TOC concentrations were generally high prior to AD 1900, with additional variability coupled mainly to changes in forest cover and agricultural land-use intensity. The last century showed significant changes, and unusually low TOC concentrations were inferred at AD 1930â1990, followed by a recent increase , largely consistent with monitoring data. Variations in sulfur emissions, with an increase in the early 1900s to a peak around AD 1980 and a subsequent decrease, were identified as an important driver of these dynamics at both sites, while processes related to the introduction of modern forestry and recent increases in precipitation and temperature may have contributed, but the effects differed between the sites. The increase in lake-water TOC concentration from around AD 1980 may therefore reflect a recovery process. Given that the effects of sulfur deposition now subside and that the recovery of lake-water TOC concentrations has reached pre-industrial levels, other forcing mechanisms related to land management and climate change may become the main drivers of TOC concentration changes in boreal lake waters in the future
Biomass and bioenergy production in organic agriculture. Consequences for soil fertility, environment, spread of animal parasites and socio-economy. BioConcnes, a 4-year interdisciplinary project.
Energy production and energy use in organic agriculture (OA) need to be addressed in order to reduce the reliance on non-renewable fossil fuels and minimize greenhouse gas (GHG) emissions. Thus, there is an obligation to find consensus between the apparent opposing aims of renewable (bio) energy production and soil fertility in OA. This project aims at designing and evaluate a combined concept for biomass and bio-energy production in OA, while considering soil fertility
Non-negative Wigner functions in prime dimensions
According to a classical result due to Hudson, the Wigner function of a pure,
continuous variable quantum state is non-negative if and only if the state is
Gaussian. We have proven an analogous statement for finite-dimensional quantum
systems. In this context, the role of Gaussian states is taken on by stabilizer
states. The general results have been published in [D. Gross, J. Math. Phys.
47, 122107 (2006)]. For the case of systems of odd prime dimension, a greatly
simplified proof can be employed which still exhibits the main ideas. The
present paper gives a self-contained account of these methods.Comment: 5 pages. Special case of a result proved in quant-ph/0602001. The
proof is greatly simplified, making the general case more accessible. To
appear in Appl. Phys. B as part of the proceedings of the 2006 DPG Spring
Meeting (Quantum Optics and Photonics section
Efficacy and toxicity of adjuvant chemotherapy in elderly patients with colorectal cancer:the ACCORE study
BACKGROUND: Elderly patients with primary colorectal cancer (CRC) are less frequently treated with adjuvant chemotherapy than younger patients due to concerns regarding toxicity and efficiency. We investigated how age, performance status (PS) and comorbidity influence treatment outcomes. PATIENTS AND METHODS: A retrospective single-centre study of 529 patients with stages IIâIII CRC treated with adjuvant chemotherapy (5-fluorouracil/capecitabine+/Ă·oxaliplatin) from 2001 to 2011 at Herlev Hospital, Denmark. Baseline characteristics, chemotherapy and outcome were analysed with respect to age after adjusting for PS and comorbidity. RESULTS: Elderly patients (>70â
years) had significantly more comorbidity (p<0.001) and poorer PS (p=0.001) than younger patients. Elderly were more frequently treated with single-agent therapy (p=0.001) and at lower initial dose (p<0.001). There was no age-dependent difference in 3-year disease-free survival (DFS; HR 1.09, 95% CI 0.80 to 1.47, p=0.59), in grade 3â5 toxicity (29% vs 28%, p=0.86) or in 10-year CRC mortality (28%, HR 1.07, p=0.71). In elderly patients, a reduction in chemotherapy dose intensity compared with full dose had no impact on DFS or CRC mortality. Elderly patients receiving <50% of planned cycles had shorter DFS (HR=1.78, p=0.020) and higher CRC mortality (HR=2.17, p=0.027) than elderly receiving all cycles. Poor PS in younger and elderly patients was related to shorter DFS (HR=1.95, p=0.002; HR=1.6, p=0.035, respectively) and overall survival (OS; HR=2.28, p<0.001; HR=2.03, p=0.002). Comorbidity in younger patients was significantly related to shorter DFS (HR 2.72, p<0.001), OS (HR 3.16, p<0.001) and higher CRC mortality (HR 2.70, p=0.001). CONCLUSIONS: Choice of regimen, primary dose reduction and given dose intensity in patients treated with adjuvant chemotherapy for CRC were highly dependent on age. However, age had no impact on DFS and CRC mortality. Comorbidity in younger patients and PS in all patients were associated with shorter DFS and higher CRC mortality
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