scholarly journals Factors affecting the conditioned reinforcing strength of stimuli in differential reinforcement of other behavior and fixed-time schedules

1980 ◽  
Vol 16 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Alexander M. Myers ◽  
Edward K. Grossman
2021 ◽  
Vol 111 (1) ◽  
pp. 231-275
Author(s):  
Ufuk Akcigit ◽  
Harun Alp ◽  
Michael Peters

Delegating managerial tasks is essential for firm growth. Most firms in developing countries, however, do not hire outside managers but instead rely on family members. In this paper, we ask if this lack of managerial delegation can explain why firms in poor countries are small and whether it has important aggregate consequences. We construct a model of firm growth where entrepreneurs have a fixed time endowment to run their daily operations. As firms grow large, the need to hire outside managers increases. Firms’ willingness to expand therefore depends on the ease with which delegation can take place. We calibrate the model to plant-level data from the United States and India. We identify the key parameters of our theory by targeting the experimental evidence on the effect of managerial practices on firm performance from Bloom et al. (2013). We find that inefficiencies in the delegation environment account for 11 percent of the income per capita difference between the United States and India. They also contribute to the small size of Indian producers, but would cause substantially more harm for US firms. The reason is that US firms are larger on average and managerial delegation is especially valuable for large firms, thus making delegation efficiency and other factors affecting firm growth complements. (JEL D22, G32, L25, L26, O14)


2019 ◽  
Vol 7 (2) ◽  
pp. 248-256
Author(s):  
Navaraj Chapagain ◽  
Bhuminandan Devkota ◽  
Gokarna Gautam ◽  
Shyam Kishor Sah ◽  
Dinesh Bhattarai

This study was designed to determine the effects of age, parity, feeding practice, Body Condition Score (BCS), blood nutritional parameters, types of anoestrus, and length of anoestrus on pregnancy rate of anoestrus buffaloes after their treatment with ovsynch protocol followed by fixed time artificial insemination. Blood samples were collected on the day ovsynch protocol and analyzed. The mean values of the nutritional parameters between different groups were compared by Students t test and pregnancy rate was compared by Fisher’s exact test or Chi-square test. The overall pregnancy rate in buffaloes was 28.6%, when checked on day 41 and 64.3% on day 102 of FTAI. Blood glucose, cholesterol, calcium and phosphorus level was found to be significantly higher (p<0.05) in pregnant than in non-pregnant buffaloes. Pregnancy rate was higher in silent estrus buffaloes. Buffaloes with BCS ≥3 had higher pregnancy rate than those with BCS < 3. Similarly, pregnancy rate was higher in lactating than in non-lactating buffaloes. While young buffaloes of age <10 year responded better than old buffaloes of age ≥10 year. Buffaloes which were free from gastrointestinal parasitic infection had higher pregnancy rate. In conclusion, ovsynch protocol produces a good pregnancy in anoestrus buffaloes; however, state of true anoestrus, older age and poor BCS with poor nutritional management adversely affect the pregnancy outcome. The role of blood nutritional parameters requires further clarification. Int. J. Appl. Sci. Biotechnol. Vol 7(2): 248-256  


Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1122 ◽  
Author(s):  
Eduardo J. Fernandez

Shaping through differential reinforcement of successive approximations to a target response has been a cornerstone procedure for the training of novel behavior. However, much of how it has traditionally been implemented occurs through informal observation, rather than any direct, systematic measurement. In the present study, we examine the use of response-independent food schedules and shaping for increasing approach and contact behaviors in petting zoo sheep. In Experiment 1, a fixed-time (FT) 15 s food schedule was used to effectively increase approach and contact behaviors in one sheep. In Experiment 2, negative reinforcement in the form of removal of the presence of a trainer was made contingent on the successful completion of approximations within a shaping procedure and later switched to food rewards. A changing-criterion design was used to empirically examine the effects of the shaping procedure during each step of the program. The result is one of the first studies to demonstrate the utility of using negative reinforcement within a shaping procedure to successfully intervene on approach/avoidance behaviors in an applied animal setting.


2009 ◽  
Vol 72 (7) ◽  
pp. 949-958 ◽  
Author(s):  
L.G.B. Siqueira ◽  
C.A.A. Torres ◽  
E.D. Souza ◽  
P.L.J. Monteiro ◽  
E.K.N. Arashiro ◽  
...  

2013 ◽  
Vol 25 (3) ◽  
pp. 581 ◽  
Author(s):  
Miguel Mellado ◽  
Claudia G. Orta ◽  
Eloy A. Lozano ◽  
Jose E. García ◽  
Francisco G. Veliz ◽  
...  

The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007–2009; 271 services) in a game-hunting ranch in a hot–arid environment (26°4′ N, 101°25′ W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P&lt;0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique.


Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5757
Author(s):  
Arkadiusz Kampczyk ◽  
Katarzyna Dybeł

Improving railway safety depends heavily on the reliability of railway turnouts. The realization of effective, reliable and continuous observations for the spatial analysis and evaluation of the technical condition of railway turnouts is one of the factors affecting safety in railway traffic. The mode and scope of monitoring changes in geometric parameters of railway turnouts with associated indicators needs improvement. The application of digital twins to railway turnouts requires the inclusion of fundamental data indicating their condition along with innovative monitoring of weather conditions. This paper presents an innovative solution for monitoring the status of temperature and other atmospheric conditions. A UbiBot WS1 WIFI wireless temperature logger was used, with an external DS18B20 temperature sensor integrated into an S49 (49E1)-type rail as Tszyn WS1 WIFI. Measurements were made between January and May (winter/spring) at fixed time intervals and at the same measurement point. The aim of the research is to present elements of a fundamental approach of applying digital twins to railway turnouts requiring the consideration and demonstration of rail temperature conditions as a component in the data acquisition of railway turnout condition data and other constituent atmospheric conditions through an innovative solution. The research showed that the presented innovative solution is an effective support for the application of digital twins to railway turnouts and ongoing surveying and diagnostic work of other elements of rail transport infrastructure. The applicability of the TgCWRII second temperature difference indicator in the monitoring of railway turnouts was also confirmed.


2018 ◽  
Vol 15 (1) ◽  
pp. 6099-6115
Author(s):  
Saad A Alkahtania ◽  
Ashraf M Mahmoud ◽  
Samer S. Abu Al-Rubb

Novel analytical study was performed in order to develop and validate new high-throughput microwell-based spectrophotometric assays for determination of omeprazole (OMZ) in its pharmaceutical formulations. The proposed assays were based on the charge-transfer (CT) reaction of OMZ with 2,3-dichloronaphthoquinone (DCNQ) and 2,3,5,6-tetrabromo-1,4-benzo-quinone (BROM). In the present study, the CT reactions was carried out in microwell plates as reaction vessels in order to increase the automation of the assays and the efficiency of its use in quality control laboratories (QCLs). All factors affecting the CT reactions were carefully studied, and the conditions were optimized. Kinetics and stoichiometry of the CT reactions were investigated, and the mechanism was postulated. Activation energy of the CT reactions was determined and found to be 13.87 and 16.27 Kcal mol−1 for the reaction of OMZ with DCNQ and BROM, respectively. The initial rate and fixed time methods were applied for generating the calibration graphs for determination of OMZ concentrations. Under the optimum conditions, the linear range was 0.145 – 1.45 x 10-4 and 1.45 – 7.25 x 10-4 M with LOD of 0.6 and 6.0 microgram ml-1 for DCNQ and BROM, respectively. Analytical performance of the proposed methods, in terms of accuracy and precision, was statistically validated and the results were satisfactory; RSD was <2.8% for both repeatability and reproducibility. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms and the recovery results (98.64 – 100.6 ± 0.25 -2.74 %) were comparable with those of the reported method. The developed method may provide a safer and economic tool for the analysis of OMZ in QCLs.


1961 ◽  
Vol 12 (6) ◽  
pp. 1216 ◽  
Author(s):  
TJ Robinson ◽  
NG Cameron

Data are presented from a factorial experiment on the effects of a number of management practices on live measurements of young growing Aberdeen Angus cattle. Sire and dam influenced most measurements, as did supplementary feeding. Season of birth and sex were the two most important factors affecting all body measurements. Year of birth had a slight effect. Correlation coefficients are presented for corresponding measurements of dams and progeny, and for liveweights and measurements at successive ages. Birth weight was highly significantly correlated with weaning and slaughter weights (r = +0.432, +0.504; P<0.001), independent of the sex effect on growth rate. Body measurements at 6 weeks had a fair predictive value for corresponding measurements at 32 weeks (pre-weaning) and 84 weeks (pre-slaughter). The growth curves of heart girth and width of hooks closely paralleled that of liveweight (r = +0.985, -0.982). Length and height measurements were less close, followed by cannon measurements and depth of chest. Width of head and round measurements were least well correlated with weight.Under conditions of nutritional stress, bone growth may continue little impaired, despite loss of liveweight. Birth weights, or weights at a fixed time shortly after birth, could have a useful predictive value in selecting cattle for high weaning weight and post-weaning weight-for-age under southern Australian conditions of husbandry.


Sign in / Sign up

Export Citation Format

Share Document