2,437 research outputs found
ECONOMIC ANALYSIS OF PHOSPHORUS - REDUCING TECHNOLOGIES IN PORK PRODUCTION
Soil phosphorus levels have increased as pork production has become concentrated. Phosphorus-based manure management regulations for land application have been proposed by policy makers. The objective of this study is to determine benefits/costs of adopting two alternatives for reducing phosphorus: synthetic amino acids or phytase. An optimization model is constructed to determine optimal excreted nitrogen and phosphorus from alternative feed ingredients. Results are derived using different manure storage and application systems. While the two alternatives are not least-cost ingredients, they become profitable when producers are constrained by land. An important result is that the net cost of manure is negative.Livestock Production/Industries,
OPTIMAL HOG SLAUGHTER WEIGHTS UNDER ALTERNATIVE PRICING SYSTEMS
Three hog genotypes are simulated to determine how producer profits, economically optimal slaughter weights, and carcass component weights change under three pricing models. Live weight pricing pays more for the fatter barrows whereas a three component (separate payments for fat, lean, and byproducts) and six component (separate payments for major primal cuts, other lean, fat, and byproducts) pricing system pay more for the leaner gilts. Implications for selection of genetic stock and pricing system are presented.Swine production management, Hog pricing systems, Hog marketing, Livestock Production/Industries,
NUTRITION AND THE ECONOMICS OF SWINE MANAGEMENT
Current methods of formulating animal rations lead to excess nutrient excretion which can potentially lead to excess manure nutrients and an increase in economic costs. These methods do not recognize the impact of diminishing returns. The objective is to simultaneously optimize feed ration composition and replacement. The results, when compared against results from a survey of feed companies, indicate that using a profit maximization rather than live weight growth maximization criterion targets nutrients to an animal's actual needs and, hence, fewer nutrients are excreted and higher returns for producers are obtained.nonlinear growth modeling, pigs, replacement, swine, Livestock Production/Industries,
Predictors and trajectory of performance status in patients with advanced cancer: A secondary data analysis of the international European Palliative Care Cancer Symptom study.
Background: Performance status, a predictor of cancer survival, and ability to maintain independent living deteriorate in advanced disease. Understanding predictors of performance status trajectory could help identify those at risk of functional deterioration, target support for independent living and reduce service costs. The relationship between symptoms, analgesics and performance status is poorly delineated. Aim: The aim of this study is to determine whether demographics, analgesics, disease characteristics, quality-of-life domains and C-reactive protein predict the trajectory of Karnofsky Performance Status (KPS) in patients with advanced cancer. Design: The study design is the secondary data analysis of the international prospective, longitudinal European Palliative Care Cancer Symptom study (ClinicalTrials.gov: NCT01362816). A multivariable regression model was built for KPS area under the curve per day (AUC). Setting and participants: This included adults with advanced, incurable cancer receiving palliative care, without severe cognitive impairment and who were not imminently dying (n = 1739). Results: The mean daily KPS AUC (n = 1052) was 41.1 (standard deviation = 14.1). Opioids (p < 0.001), co-analgesics (p = 0.023), poorer physical functioning (p < 0.001) and appetite loss (p = 0.009) at baseline were explanatory factors for lower KPS AUC. A subgroup analysis of participants with C-reactive protein data (n = 240) showed that only C-reactive protein (p = 0.040) and physical function (p < 0.001) were associated with lower KPS AUC. Conclusion: This study is novel in determining explanatory factors for subsequent functional trajectories in an international dataset and identifying systemic inflammation as a candidate therapeutic target to improve functional performance. The effect of interventions targeting physical function, appetite and inflammation, such as those used for cachexia management, on maintaining functional status in patients with advanced cancer needs to be investigated
Impact of Natural Blind Spot Location on Perimetry.
We study the spatial distribution of natural blind spot location (NBSL) and its impact on perimetry. Pattern deviation (PD) values of 11,449 reliable visual fields (VFs) that are defined as clinically unaffected based on summary indices were extracted from 11,449 glaucoma patients. We modeled NBSL distribution using a two-dimensional non-linear regression approach and correlated NBSL with spherical equivalent (SE). Additionally, we compared PD values of groups with longer and shorter distances than median, and larger and smaller angles than median between NBSL and fixation. Mean and standard deviation of horizontal and vertical NBSL were 14.33° ± 1.37° and -2.06° ± 1.27°, respectively. SE decreased with increasing NBSL (correlation: r = -0.14, p \u3c 0.001). For NBSL distances longer than median distance (14.32°), average PD values decreased in the upper central (average difference for significant points (ADSP): -0.18 dB) and increased in the lower nasal VF region (ADSP: 0.14 dB). For angles in the direction of upper hemifield relative to the median angle (-8.13°), PD values decreased in lower nasal (ADSP: -0.11 dB) and increased in upper temporal VF areas (ADSP: 0.19 dB). In conclusion, we demonstrate that NBSL has a systematic effect on the spatial distribution of VF sensitivity
An H2CO 6cm Maser Pinpointing a Possible Circumstellar Torus in IRAS18566+0408
We report observations of 6cm, 3.6cm, 1.3cm, and 7mm radio continuum,
conducted with the Very Large Array towards IRAS18566+0408, one of the few
sources known to harbor H2CO 6cm maser emission. Our observations reveal that
the emission is dominated by an ionized jet at cm wavelengths. Spitzer/IRAC
images from GLIMPSE support this interpretation, given the presence of 4.5um
excess emission at approximately the same orientation as the cm continuum. The
7mm emission is dominated by thermal dust from a flattened structure almost
perpendicular to the ionized jet, thus, the 7mm emission appears to trace a
torus associated with a young massive stellar object. The H2CO 6cm maser is
coincident with the center of the torus-like structure. Our observations rule
out radiative pumping via radio continuum as the excitation mechanism for the
H2CO 6cm maser in IRAS18566+0408.Comment: 20 pages, 4 figures, ApJ (in press
Creation, doubling, and splitting, of vortices in intracavity second harmonic generation
We demonstrate generation and frequency doubling of unit charge vortices in a
linear astigmatic resonator. Topological instability of the double charge
harmonic vortices leads to well separated vortex cores that are shown to
rotate, and become anisotropic, as the resonator is tuned across resonance
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An Artificial Intelligence Approach to Detect Visual Field Progression in Glaucoma Based on Spatial Pattern Analysis.
Purpose: To detect visual field (VF) progression by analyzing spatial pattern changes.
Methods: We selected 12,217 eyes from 7360 patients with at least five reliable 24-2 VFs and 5 years of follow-up with an interval of at least 6 months. VFs were decomposed into 16 archetype patterns previously derived by artificial intelligence techniques. Linear regressions were applied to the 16 archetype weights of VF series over time. We defined progression as the decrease rate of the normal archetype or any increase rate of the 15 VF defect archetypes to be outside normal limits. The archetype method was compared with mean deviation (MD) slope, Advanced Glaucoma Intervention Study (AGIS) scoring, Collaborative Initial Glaucoma Treatment Study (CIGTS) scoring, and the permutation of pointwise linear regression (PoPLR), and was validated by a subset of VFs assessed by three glaucoma specialists.
Results: In the method development cohort of 11,817 eyes, the archetype method agreed more with MD slope (kappa: 0.37) and PoPLR (0.33) than AGIS (0.12) and CIGTS (0.22). The most frequently progressed patterns included decreased normal pattern (63.7%), and increased nasal steps (16.4%), altitudinal loss (15.9%), superior-peripheral defect (12.1%), paracentral/central defects (10.5%), and near total loss (10.4%). In the clinical validation cohort of 397 eyes with 27.5% of confirmed progression, the agreement (kappa) and accuracy (mean of hit rate and correct rejection rate) of the archetype method (0.51 and 0.77) significantly (P \u3c 0.001 for all) outperformed AGIS (0.06 and 0.52), CIGTS (0.24 and 0.59), MD slope (0.21 and 0.59), and PoPLR (0.26 and 0.60).
Conclusions: The archetype method can inform clinicians of VF progression patterns
Modulation of 1,25-dihydroxyvitamin D3-dependent Ca2+ uptake in skeletal muscle by protein kinase C
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