4,752 research outputs found
Comparison of parametric, orthogonal, and spline functions to model individual lactation curves for milk yield in Canadian Holsteins
Test day records for milk yield of 57,390 first lactation Canadian Holsteins were analyzed with a linear model that included the fixed effects of herd-test date and days in milk (DIM) interval nested within age and calving season.
Residuals from this model were analyzed as a new variable and fitted with a five parameter model, fourth-order Legendre polynomials, with linear, quadratic and cubic spline models with three knots. The fit of the models was
rather poor, with about 30%-40% of the curves showing an adjusted R-square lower than 0.20 across all models. Results underline a great difficulty in modelling individual deviations around the mean curve for milk yield. However, the Ali and Schaeffer (5 parameter) model and
the fourth-order Legendre polynomials were able to detect two basic shapes of individual deviations among the mean curve. Quadratic and, especially, cubic spline functions had better fitting performances but a poor predictive
ability due to their great flexibility that results
in an abrupt change of the estimated curve when data are missing. Parametric and orthogonal polynomials seem to be robust and affordable under this standpoint
Intangible Capital and Economic Growth
Published macroeconomic data traditionally exclude most intangible investment from measured GDP. This situation is beginning to change, but our estimates suggest that as much as 3 trillion of business intangible capital stock. To assess the importance of this omission, we add capital to the standard sources-of-growth framework used by the BLS, and find that the inclusion of our list of intangible assets makes a significant difference in the observed patterns of U.S. economic growth. The rate of change of output per worker increases more rapidly when intangibles are counted as capital, and capital deepening becomes the unambiguously dominant source of growth in labor productivity. The role of multifactor productivity is correspondingly diminished, and labor's income share is found to have decreased significantly over the last 50 years.
Torts - Negligence - California’s guest statute does not apply to accidents which occur off public highways. O’Donnell v. Mullaney (Cal. 1967).
This recent case discusses O\u27Donnell v. Mullaney (Cal. 1967)
The Policy Implications of Evaluation Research: Some Issues Raised by the Fishman Study of Rehabilitation and Diversion Services
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The social and economic bases of network multiplexity: Exploring the emergence of multiplex ties
The goal of this article is to shed light on the role of tie content in the evolution of multiplex ties – i.e., ties featuring both an economic and a social component – in interorganizational networks. The authors clarify and extend the theoretical framework on network multiplexity by testing the extent to which two distinct tie content-related logics – social interaction and economic exchange – and their underlying mechanisms lead to the emergence of multiplex ties. Results from a longitudinal network analysis of firms located in an Italian multimedia cluster support the authors’ hypotheses, confirming that both social and economic drivers contribute to the emergence of network multiplexity, and that social ties have a stronger impact than economic ties on this process, thus providing further insight into the microdynamics of network evolution
Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)
Cap rock characterization of geothermal systems is often neglected despite fracturing may reduce its efficiency and favours fluid migration. We investigated the siliciclastic cap rock of Rosario de La Frontera geothermal system (NW Argentina) in order to assess its quality as a function of fracture patterns and related thermal alteration. Paleothermal investigations (XRD on fine-grained fraction of sediments, organic matter optical analysis and fluid inclusions on veins) and 1D thermal modelling allowed us to distinguish the thermal fingerprint associated to sedimentary burial from that related to fluid migration. The geothermal system is hosted in a Neogene N-S anticline dissected by high angle NNW- and ENE-striking faults. Its cap rock can be grouped into two quality categories: • rocks acting as good insulators, deformed by NNW–SSE and E–W shear fractures, NNE-SSW gypsum- and N-S-striking calcite-filled veins that developed during the initial stage of anticline growth. Maximum paleo-temperatures (< 60 °C) were experienced during deposition to folding phases.• rocks acting as bad insulators, deformed by NNW-SSE fault planes and NNW- and WNW-striking sets of fractures associated to late transpressive kinematics. Maximum paleo-temperatures higher than about 115 °C are linked to fluid migration from the reservoir to surface (with a reservoir top at maximum depths of 2.5 km) along fault damage zones.This multi-method approach turned out to be particularly useful to trace the main pathways of hot fluids and can be applied in blind geothermal systems where either subsurface data are scarce or surface thermal anomalies are lacking.Fil: Maffucci, R.. Universita Degli Studi Della Tuscia; Italia. Universita Degli Studi Roma Tre; ItaliaFil: Corrado, Sveva. Universita Degli Studi Roma Tre; ItaliaFil: Aldega, L.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Bigi, S.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Chiodi, Agostina Laura. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Salta. Instituto de Investigaciones en EnergĂa no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de FĂsica. Instituto de Investigaciones en EnergĂa no Convencional; ArgentinaFil: Di Paolo, L.. Eni E&P Division; ItaliaFil: Giordano, G.. Universita Degli Studi Roma Tre; ItaliaFil: Invernizzi, C.. Universita Degli Di Camerino; Itali
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