Sire effects on neonatal lamb vigour and following-behaviour

2014 ◽  
Vol 54 (6) ◽  
pp. 745 ◽  
Author(s):  
R. L. Hergenhan ◽  
G. N. Hinch ◽  
D. M. Ferguson

The ability of the lamb to maintain contact with the ewe as she moves away from the birth site is critical to the lamb’s subsequent survival. If this contact is compromised then lamb loss is likely to occur due to starvation/mismothering. This study uses sires from the Sheep CRC Information Nucleus Flock to compare the effect of selection of sires within the Merino breed for high or low losses due to starvation/mismothering on neonatal lamb vigour. Lamb vigour was measured using conventional measures of time to perform early neonatal behaviours, early physiological measures (rectal temperatures and blood glucose), and performance in a modified barrier test while under physiological stress from cold exposure. Lambs were exposed to cold at a time (4–6 h after birth) when the ewe is likely to be moving away from the birth site and therefore when losses due to starvation/mismothering are likely to begin. Progeny from the high-loss sires were significantly (P < 0.05) slower to attempt to stand, and to stand, than progeny from the no-loss sires and tended to be slower to reach the udder and suckle (P = 0.07). Lambs from the no-loss group also had a significantly (P < 0.01) higher vigour score than the high-loss group. There was no effect of sire group on the performance of lambs in the modified barrier test; however, cold-treated lambs performed poorly in the test compared with control lambs. It was concluded that sire can have an effect on lamb vigour, but it does not necessarily translate into effects on later following-behaviour while under stressful conditions.

Author(s):  
Chaochao Lin ◽  
Matteo Pozzi

Optimal exploration of engineering systems can be guided by the principle of Value of Information (VoI), which accounts for the topological important of components, their reliability and the management costs. For series systems, in most cases higher inspection priority should be given to unreliable components. For redundant systems such as parallel systems, analysis of one-shot decision problems shows that higher inspection priority should be given to more reliable components. This paper investigates the optimal exploration of redundant systems in long-term decision making with sequential inspection and repairing. When the expected, cumulated, discounted cost is considered, it may become more efficient to give higher inspection priority to less reliable components, in order to preserve system redundancy. To investigate this problem, we develop a Partially Observable Markov Decision Process (POMDP) framework for sequential inspection and maintenance of redundant systems, where the VoI analysis is embedded in the optimal selection of exploratory actions. We investigate the use of alternative approximate POMDP solvers for parallel and more general systems, compare their computation complexities and performance, and show how the inspection priorities depend on the economic discount factor, the degradation rate, the inspection precision, and the repair cost.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3066
Author(s):  
Michał Patyk ◽  
Przemysław Bodziony ◽  
Zbigniew Krysa

Selection and assessment of mining equipment used in open pit rock mines relies chiefly on estimates of overall exploitation cost. The rational arrangement of mining equipment and systems comprising loading machines, haul trucks and crushing plants should be preceded by a thorough analysis of technical and economic aspects, such as investment outlays and the costs of further exploitation, which largely determine the costs of mining operations and the deposit value. Additionally, the operational parameters of the mining equipment ought to be considered. In this study, a universal set of evaluation criteria has been developed, and an evaluation method has been applied for the selection of surface mining equipment and the processing system to be operated in specific mining conditions, defined by the user. The objective of this study is to develop and apply the new methodology of multi-criteria selection of open pit rock mining equipment based on multiple criteria decision-making (MCDM) procedures, to enable the optimization of loading, handling and crushing processes. The methodology, underpinned by the principles of MCDM, provides the dedicated ranking procedures, including the ELECTRE III. The applied methodology allows the alternative options (variants) to be ranked accordingly. Ultimately, a more universal methodology is developed, applicable in other surface mines where geological and mining conditions are similar. It may prove particularly useful in selection and performance assessment of mining equipment and process line configurations in mining of low-quality rock deposits. Therefore, we undertook to develop universal criteria and applications for the selection and performance assessment of process machines for surface mines, taking into account environmental aspects as well as deposit quality.


2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Sanjiv Ramachandran ◽  
George Lesieutre

Particle impact dampers (PIDs) have been shown to be effective in vibration damping. However, our understanding of such dampers is still limited, based on the theoretical models existing today. Predicting the performance of the PID is an important problem, which needs to be investigated more thoroughly. This research seeks to understand the dynamics of a PID as well as those parameters which govern its behavior. The system investigated is a particle impact damper with a ceiling, under the influence of gravity. The base is harmonically excited in the vertical direction. A two-dimensional discrete map is obtained, wherein the variables at one impact uniquely dictate the variables at the next impact. This map is solved using a numerical continuation procedure. Periodic impact motions and “irregular” motions are observed. The effects of various parameters such as the gap clearance, coefficient of restitution, and the base acceleration are analyzed. The dependence of the effective damping loss factor on these parameters is also studied. The loss factor results indicate peak damping for certain combinations of parameters. These combinations of parameters correspond to a region in parameter space where two-impacts-per-cycle motions are observed over a wide range of nondimensional base accelerations. The value of the nondimensional acceleration at which the onset of two-impacts-per-cycle solutions occurs depends on the nondimensional gap clearance and the coefficient of restitution. The range of nondimensional gap clearances over which two-impacts-per-cycle solutions are observed increases as the coefficient of restitution increases. In the regime of two-impacts-per-cycle solutions, the value of nondimensional base acceleration corresponding to onset of these solutions initially decreases and then increases with increasing nondimensional gap clearance. As the two-impacts-per-cycle solutions are associated with high loss factors that are relatively insensitive to changing conditions, they are of great interest to the designer.


2016 ◽  
Vol 29 (4) ◽  
pp. 841-849
Author(s):  
ADRIANA QUEIROZ DE ALMEIDA ◽  
SIMONE ALVES SILVA ◽  
VANESSA DE OLIVEIRA ALMEIDA ◽  
DEOCLIDES RICARDO DE SOUZA ◽  
GILMARA DE MELO ARAÚJO

ABSTRACT The knowledge about genetic diversity of jatropha crop is important for genetic conservation resources and breeding of this species. The aim of this study was to evaluate the genetic diversity and performance of jatropha clones through morphological characterization to selection of clonal varieties for biofuels production. The clones were obtained through shoot cuttings from previous selection in a population of half-sibs progenies. The morphoagronomic analyses of clones was carried out at 180 days after transplantation and were evaluated plant height, stem diameter, number of primary branches and number of secondary branches, number of bunches and number of fruits per plant. Evaluating clones performance, significant results were found for the number of secondary branches. About analysis of genetic diversity, the measures of dissimilarity genetic varied from 0.62 to 13.11, this way, the UFRBPR14 and UFRBPR15 clones were more divergent. The Tocher method was efficient to verify formation of four groups. The characteristics that most contributed to the divergence among clones were branches number, height and number of bunches, and, stem diameter had lower contribution. The jatropha clones differed only in the secondary branches number and multivariate analysis showed divergence among the jatropha clones with formation of four groups. Also, branches number, plant height and number of bunches were characteristic that contributed to genetic divergence.


2019 ◽  
Vol 3 (5) ◽  
pp. 815-826 ◽  
Author(s):  
James Day ◽  
Preya Patel ◽  
Julie Parkes ◽  
William Rosenberg

Abstract Introduction Noninvasive tests are increasingly used to assess liver fibrosis and determine prognosis but suggested test thresholds vary. We describe the selection of standardized thresholds for the Enhanced Liver Fibrosis (ELF) test for the detection of liver fibrosis and for prognostication in chronic liver disease. Methods A Delphi method was used to identify thresholds for the ELF test to predict histological liver fibrosis stages, including cirrhosis, using data derived from 921 patients in the EUROGOLF cohort. These thresholds were then used to determine the prognostic performance of ELF in a subset of 457 patients followed for a mean of 5 years. Results The Delphi panel selected sensitivity of 85% for the detection of fibrosis and &gt;95% specificity for cirrhosis. The corresponding thresholds were 7.7, 9.8, and 11.3. Eighty-five percent of patients with mild or worse fibrosis had an ELF score ≥7.7. The sensitivity for cirrhosis of ELF ≥9.8 was 76%. ELF ≥11.3 was 97% specific for cirrhosis. ELF scores show a near-linear relationship with Ishak fibrosis stages. Relative to the &lt;7.7 group, the hazard ratios for a liver-related outcome at 5 years were 21.00 (95% CI, 2.68–164.65) and 71.04 (95% CI, 9.4–536.7) in the 9.8 to &lt;11.3 and ≥11.3 subgroups, respectively. Conclusion The selection of standard thresholds for detection and prognosis of liver fibrosis is described and their performance reported. These thresholds should prove useful in both interpreting and explaining test results and when considering the relationship of ELF score to Ishak stage in the context of monitoring.


1999 ◽  
Vol 12 (1) ◽  
pp. 56-64
Author(s):  
Marcia Goby Cohen
Keyword(s):  

2018 ◽  
Vol 6 (2) ◽  
pp. 124-146 ◽  
Author(s):  
Emmanuel Lubem Asenge ◽  
Hembadoon Sarah Diaka ◽  
Alexander Terna Soom

Many studies indicates that entrepreneurial mindset is a critical factor in the accumulation, evaluation and selection of the knowledge which can lead an individual into potential business opportunities thereby enhancing entrepreneurial outcomes such as firm performance. This study examined the effect of entrepreneurial mindset on the performance of small and medium scale enterprises in Benue State. The focus of the research was to measure the entrepreneurs’ mindset exhibited through innovativeness, creativity, business alertness and risk taking and how these attributes contributed to the performance of SMEs. The research focused on a population of 650 small and medium scale enterprises based in Makurdi metropolis. A questionnaire was used to collect data from a sample of 250 SMEs in Makurdi metropolis which were selected through stratified random sampling method. Collected data were analyzed using descriptive and inferential statistics with the aid of Statistical Package for Social Sciences (SPSS). Correlation and multiple regression analysis were employed to analyse the data and test the hypotheses. The study revealed that innovativeness, creativity, business alertness and risk taking were significant in affecting performance of SMEs. The study concluded that entrepreneurial mindset or lack of it has a major effect on SMEs performance and if any economy is bended towards development and growth, it would have to embrace this concept. It recommended that all the policy makers and all stake holders should re-strategize and create forums that can promote entrepreneurial mindset among the existing and potential entrepreneurs.


2019 ◽  
Vol 26 (2) ◽  
pp. 85-92
Author(s):  
Michał Kuźniar ◽  
Marek Orkisz

Abstract The paper describes the selection of a distributed propulsion for the AOS H2 motor glider (selection of engines, their number, and propellers) and determination of its performance. This analysis is related to the research conducted on environment friendly and hybrid propulsions in various research centres. The main aim of the analyses conducted is to increase the performance of vehicles powered by electric motors. The batteries have a low density of energy, i.e. the ratio of mass to cumulated energy. Instead of a battery set, it is possible to apply a hybrid-electric system, where the combustion engine works as a generator or an electric-hydrogen generator, where the hydrogen cell supports a small set of batteries. One of such flying vehicles, fitting in this trend, is the AOS H2 motor glider built at the Rzeszow University of Technology in cooperation with other universities. It is a hybrid aircraft, equipped with a hydrogen cell, which together with a set of batteries is a source of electricity for the Emrax 268 electric motor. To increase the vehicle's performance (the range and flight duration), it is possible to use a distributed propulsion. This type of propulsion consists in placing many electric motors along the wingspan of the aircraft. Appropriate design of such a system (propeller diameters, engine power, number of engines) can improve the aerodynamic and performance parameters of the airframe. An analysis of the performance for the selected flight trajectory for this propulsion variant was conducted and compared to the performance of the AOS H2 motor glider equipped with traditional propulsion. The consumption of hydrogen was also determined for both systems. The results obtained were presented in the diagrams and discussed in the conclusions.


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