Incentive Effect of Piece-Rate Contracts: Evidence from Two Small Field Experiments

2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Lan Shi
Keyword(s):  
Field Experiments ◽  
Control Group ◽  
Treatment Groups ◽  
Piece Rate ◽  
Productivity Increase ◽  
Tree Thinning ◽  
Randomized Control ◽  
The Difference ◽  
The Right ◽  
Piece Rates

Abstract We conducted two field experiments in a tree-thinning setting. In one experiment, we switched the pay of a randomly chosen half (the treatment group) from hourly wages to piece-rate pay. Workers in the control group were paid hourly wages throughout. In the second experiment, workers were switched from hourly to piece-rate pay all at once. The difference-in-difference and before-after estimates suggest that the productivity increase was on the order of 20-23 percent. Although the sample size is small, the estimates are statistically significant and robust. While the quality did not drop, the study highlights the measurement costs in setting up the right level of piece rates. We also discuss the strengths and weaknesses of using randomized control (and treatment) groups or not in conducting field experiments within firms.

scholarly journals The Effect of Aloe Vera Extract to Extensive Lesion and Expression of Transforming Growth Factor (TGF-β) on Alkaline Chemical Trauma Cornea Model

2018 ◽  
Vol 1 (2) ◽  
pp. 1-17
Author(s):  
Fahcreza ◽  
Elsa Iskandar ◽  
Rachmat Hidayat ◽  
Petty Purwanita ◽  
Anang Tribowo ◽  
...  
Keyword(s):  
Wound Healing ◽  
Growth Factor ◽  
Wistar Rats ◽  
Aloe Vera ◽  
Control Group ◽  
Treatment Groups ◽  
White Rats ◽  
Significant Difference ◽  
The Difference ◽  
In Cells

Abstract Background: Chemical trauma to the cornea is an emergency condition of the eye that requires early diagnosis and good treatment. Alkaline have ability to saponify fatty acids in cells and cell membranes which can make penetration into the stroma and destroy proteoglycans and collagen in cells. Aloe vera (AV) contains several active substances that are reported to have anti-inflammatory, immunomodulatory, and wound healing effects. AV has been reported to accelerate the healing process of corneal epithelial defects by increasing fibroblast proliferation, collagen production and growth factor production. This study aims to determine the difference between the effect of aloe vera extract with a concentration of 10%, 20%, 40% and BSS on the healing of extensive corneal lesions in white wistar rats alkaline trauma models. Method: This study was an experimental study with a pre and posttest only with control group design in vivo approach to 30 Wistar white rats which were divided into 5 treatment groups for 3 days. Comparative analysis of effectiveness using the ANNOVA test or the Kruskal Wallis test and continued by the post hoc test. Results: Based on the one way ANOVA test there was a statistically significant difference in effectiveness between the five treatment groups on the percentage of corneal wound healing area and TGF-β expression with an assessment of p = 0,000 each. The administration of alloevera (AV) concentration of 20% had a significant difference in percentage of healing of corneal lesions and TGF-β expression compared with other treatment groups with p = 0,000 each. Large differences in the area of corneal lesions in the 40% AV group were -0.45 in the BBS group, 0.146 in the 10% AV group, 0.493 in the 20% AV group. The difference in the AV group 10% was 0.30 in the BBS group, -064 in the AV group 20%, and -0.14 in the AV group 40%. However, TGFβ expression in the normal control group that did not receive treatment was 54.94 (53.21-56-12). TGFβ levels in the BSS group were 10.44, the 10% aloe vera group was 25.43, 47.99 for the 20% aloe vera group and 37.95 for the 40% aloe vera group. Conclusion: There is a difference between the effect of aloe vera extract with concentrations of 10%, 20%, 40% and BSS on the extensive healing of corneal lesions in white wistar rats with alkaline chemical trauma models.

scholarly journals Right-to-Choose Auctions: A Field Study of Water Markets in the Limari Valley of Chile

2010 ◽  
Vol 39 (2) ◽  
pp. 213-226 ◽  
Author(s):  
Jonathan E. Alevy ◽  
Oscar Cristi ◽  
Oscar Melo
Keyword(s):  
Field Study ◽  
Research Team ◽  
Field Experiments ◽  
Time Preferences ◽  
Water Markets ◽  
Risk Attitudes ◽  
Sequential Auction ◽  
The Difference ◽  
Water Volumes ◽  
The Right

Field experiments were conducted with farmers in the Limari Valley of Chile to test extant theory on right-to-choose auctions. Water volumes that differed by reservoir source and time of availability were offered for sale by the research team. The auctions were supplemented by protocols to elicit risk and time preferences of bidders. We find that the right-to-choose auctions raise significantly more revenue than the benchmark sequential auction. Risk attitudes explain a substantial amount of the difference in bidding between auction institutions, consonant with received theory. The auction bidding revealed distinct preferences for water types, which has implications for market re-design.

Evaluation of Biomechanically Corrected Intraocular Pressure Measurements in Keratoconus and Forme Fruste Keratoconus

2020 ◽  
Vol 63 (6) ◽  
pp. 541-549
Author(s):  
Tomoya Nishida ◽  
Takashi Kojima ◽  
Takahiro Kataoka ◽  
Naoki Isogai ◽  
Yoko Yoshida ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Biomechanical Properties ◽  
Control Group ◽  
Pressure Measurements ◽  
Altman Plot ◽  
Significant Difference ◽  
The Difference ◽  
The Right ◽  
Corneal Biomechanical Properties ◽  
Forme Fruste Keratoconus

<b><i>Introduction:</i></b> Although biomechanically corrected intraocular pressure (bIOP) is available, the effectiveness of intraocular pressure (IOP) correction in keratoconus and forme fruste keratoconus (FFK) eyes has not been investigated. <b><i>Objective:</i></b> Evaluation of bIOP measurements in eyes with keratoconus and FFK. <b><i>Methods:</i></b> Forty-two eyes in 21 patients with keratoconus in one eye and FFK in the fellow eye were examined (KC/FFK group; mean age 24.62 ± 8.6 years; 16 males and 5 females). The control group consisted of 62 eyes in 31 unaffected subjects (mean age 26.26 ± 3.64 years; 15 males and 16 females). The bIOP was determined using a Scheimpflug-based tonometer (Corvis Scheimpflug Technology [Corvis ST®]) after measuring the IOP with a conventional non-contact tonometer (NIOP). The agreement between NIOP and bIOP values was examined using the Bland-Altman plot. The difference between NIOP and bIOP (bIOP correction amount) was compared between keratoconus and FFK eyes. <b><i>Results:</i></b> In the control group, there were no significant differences between right and left eyes in both NIOP and bIOP values (<i>p</i> = 0.975 and <i>p</i> = 0.224, respectively). In the KC/FFK group, NIOP values were significantly lower in the keratoconus eyes (9.93 ± 1.96 mm Hg) than in the FFK eyes (12.23 ± 3.03 mm Hg; <i>p</i> = 0.0003). There was no significant difference in bIOP values between the right and left eyes of the KC/FFK group (<i>p</i> = 0.168). The bIOP correction amount was significantly increased in keratoconus eyes (3.58 ± 2.12 mm Hg) compared to in FFK eyes (1.80 ± 3.32 mm Hg; <i>p</i> = 0.011). <b><i>Conclusions:</i></b> For eyes with keratoconus and FFK, the bIOP method is effective to adjust IOP measurements based on corneal biomechanical properties.

scholarly journals Dietary Zinc Supplementation to Prevent Chronic Copper Poisoning in Sheep

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 227 ◽  
Author(s):  
Antonio Minervino ◽  
Marta López-Alonso ◽  
Raimundo Barrêto Júnior ◽  
Frederico Rodrigues ◽  
Carolina Araújo ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Control Group ◽  
Treatment Groups ◽  
Inductively Coupled ◽  
Hepatic Copper ◽  
Cu Accumulation ◽  
The Difference ◽  
Hepatic Metallothionein

The aim of this study was to evaluate whether zinc (Zn) supplementation protects against hepatic copper (Cu) accumulation in copper-loaded sheep. Forty cross-bred lambs were assigned to five experimental groups. These included the control group (C) and four treatment groups that received Cu and/or Zn supplementation (dry matter (DM) basis) over 14 weeks, as follows: Cu (450 mg Cu/kg); Zn-35 (450 mg Cu + 35 mg Zn/kg); Zn-150 (450 mg Cu + 150 mg Zn/kg); and Zn-300 (450 mg Cu + 300 mg Zn/kg). Blood, liver, and bile samples were obtained for mineral determination by inductively coupled plasma optical emission spectrometry (ICP–OES). The hepatic metallothionein (MT) concentrations were also determined. At the end of the experiment, hepatic Cu concentrations were higher in all Cu-supplemented groups than in C. Hepatic Cu accumulation was lower in the groups receiving the Zn supplementation than in the Cu group, although the difference was only statistically significant (66%) in the Zn-300 group. The MT concentrations tended to be higher (almost two-fold) in the Zn groups (but were not dose related) than in the C and Cu groups, and they were related to hepatic Zn concentrations. Zn supplementation at 300 mg/kg DM is useful for preventing excessive hepatic Cu accumulation in sheep exposed to high dietary concentrations of Cu.

scholarly journals THE INFLUENCE OF RED FRUIT (PANDANUS CONOIDEUS LAM.) OIL ON GLUTATHIONE PEROXIDASE LEVEL AT MAXIMUM PHYSICAL ACTIVITY

2018 ◽  
Vol 11 (13) ◽  
pp. 104 ◽  
Author(s):  
Fajar Apollo Sinaga ◽  
Nora Susanti
Keyword(s):  
Physical Activity ◽  
Glutathione Peroxidase ◽  
Experimental Research ◽  
T Test ◽  
Control Group ◽  
Male Mice ◽  
Treatment Groups ◽  
Randomized Control ◽  
Fruit Oil

Objectives: This study aims to see the effect of red fruit oil (RFO) on glutathione peroxidase (GPx) level at maximum physical activity.Methods: This study is an experimental research using the design of randomized control group pretest-posttest. This study was using 24 male mice divided into four groups, the control group was given aquadest, the treatment groups P1, P2, and P3 were given the RFO orally of 0.15 ml/kg BW, 0.3 ml/kg BW, and 0.6 ml/kg BW, respectively, for a month. The level of GPx was checked for all groups at the beginning of study and after the maximum physical activity. The obtained data were then tested statistically using t-test and ANOVA.Results: The result shows the RFO supplementation during exercise increased the GPx level in P1, P2, and P3 groups with p<0.05, and the higher RFO dosage resulted in higher GPx level at p<0.05.Conclusion: The conclusion of this study is the RFO could increase the level of GPx at maximum physical activity.

scholarly journals Tepung ulat sagu (Rhyinchophorus ferrugineus) imunomodulator Nitric Oxide (NO) sirkulasi mencit terapi antimalaria standar

2018 ◽  
Vol 6 (2) ◽  
pp. 131-138
Author(s):  
Ariani Ariani ◽  
Gemala Anjani ◽  
Muchlis Achsan Udji Sofro ◽  
Kis Djamiatun
Keyword(s):  
Control Group ◽  
Treatment Groups ◽  
Antimalarial Therapy ◽  
Post Test ◽  
The Mean ◽  
Randomized Control ◽  
Post Hoc ◽  
Group Post ◽  
One Way Anova

Background : Sago worm flour (Rhyinchophorus ferrugineus)is a coconut beetle larvae that is processed into flour.This flour contains antioxidants as well as arginine, both of which play a role in modulating oxidative stress including NO involved in immunopathology of cerebral malaria.Objectives : To prove the immunomodulator role of sago worm flour in decreasing circulation  NO level at mice  who received standard antimalarial therapy  Dihydroartemisinin Piperaquine (DHP)Methods : This study was randomized control group post test only design by using 23 Swiss mice which divided into 5 group consist of : K(-) normal mice; K(+) inoculated woth Plasmodium berghei ANKA (PbA); X1 received DHP; X2 received sago worm flour; X3 received both of sago worm flour and DHP. All treatment groups X1,X2 and X3 were inoculated by PbA before treatmen were given. Serum circulation NO level was assessed by ELISA. statistical analysis used was One Way ANOVA followed by Bonferroni post hoc test.Results : The mean  NO level in K(-), K(+), X1, X2, and X3 were 1.008 μmol/mL, K(+) 1.338 μmol/mL; while at treatment X1 1.143 μmol/mL, X2 1.410 μmol/mL, dan X3 0.886 μmol/mL. One way ANOVA showed that they were significantly different (p=0.001). Bonferroni post hoc test of X2 was  proportional to K(+) (p=1.000), whole had NO level lower than either K(+)(p=0.009) or X2 (p=0.002). Conclusion : The immunomodulatory effects of sago worm flour (Rhyinchophorus ferrugineus) reduced circulating NO levels in standard antimalarial therapy recipients.

scholarly journals Analysis of hard tissue facial symmetry after unilateral mandibular reconstruction

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Mohamad Saleh Khaghaninejad ◽  
Leila Khojastepour ◽  
Hanie Ahmadi ◽  
Saeid Tavanafar ◽  
Alireza Ebrahimi ◽  
...  
Keyword(s):  
Bilateral Symmetry ◽  
Asymmetry Index ◽  
Mandibular Reconstruction ◽  
Control Group ◽  
Study Group ◽  
The Mean ◽  
The Difference ◽  
Bilateral Differences ◽  
Mean Differences ◽  
The Right

Abstract Background This study aimed to determine how successful reconstruction of the mandible can recover the symmetry. Materials and methods All patients who underwent surgical treatment for unilateral mandibular reconstruction in 4 years were retrospectively examined. Bilateral differences of gonion (GO) positions were measured in 3 dimensions based on immediate postoperative computed tomography. The data collected was analyzed in 3 ways: First, the comparison of bilateral differences of GO in 3 dimensions. Second, the mean Asymmetry Index in control subjects was used to divide all cases into three groups: “Symmetry,” “Asymmetry,” and “Marked asymmetry.” Third, “maximum normal asymmetry” was calculated, and all cases were categorized as below and above maximum normal asymmetry. The difference between two gonial angles was used to determine the amount of asymmetry. Results Forty-seven patients and 47 normal adults were enrolled. The mean bilateral GO difference in the control group was higher than in the study group patients, but it was not statistically significant. The mean Asymmetry Index for the control group was not also significantly higher than the study cases. The study group was “Symmetric” in 78.7% of the cases whereas the control group in 91.4%, 19.1% of the study group and 8.5% of controls were “Asymmetric,” and 2.1% of study cases and 0% of controls were “Markedly Asymmetric.” Maximum normal asymmetry was 82.9% in the study group and 97.8% in the control group. The mean differences between the right and left gonial angles were higher in the study group, but it was not significant (P = 0.1). Conclusions Our study’s results showed that bilateral symmetry in mandibular reconstruction patients was satisfactory and similar to the normal individuals.

A Clinical Study of Acupuncture and SSP (Silver Spike Point) Electro-therapy for Dry Eye Syndrome

2006 ◽  
Vol 34 (02) ◽  
pp. 197-206 ◽  
Author(s):  
Kuo-Lieh Tseng ◽  
Hsu-Jan Liu ◽  
Kam-Yuen Tso ◽  
Lin-Chung Woung ◽  
Yi-Chang Su ◽  
...  
Keyword(s):  
Dry Eye ◽  
Dry Eye Syndrome ◽  
Control Group ◽  
Artificial Tears ◽  
Schirmer Test ◽  
Analog Scale ◽  
Treatment Groups ◽  
Significant Difference ◽  
Before And After ◽  
The Right

The present study was designed as a clinical trial to assess the efficacy of acupuncture and silver spike point (SSP) electro-therapy on dry eye syndrome. A total of 43 dry eye syndrome patients participated in the present study. Subjects were divided into control, acupuncture and SSP electro-therapy groups. The three groups were all given artificial tears treatment. Patients in the treatment groups were given two 20-minute treatments of either acupuncture or SSP. Assessment was carried out using the Basal Schirmer test, tear break-up time (BUT), visual analog scale (VAS) and an overall score of eye condition. After four weeks of treatment, both the acupuncture and SSP treatment groups showed improvements over the control group, in Schirmer tests of the left eye and average tearing of both eyes. After 8 weeks of treatment, both treatment groups showed improvements over the control group both in Schirmer tests and VAS. For the right eye, treatment groups showed significant improvements in Schirmer test and VAS versus the control group averages for both eyes. There was no significant difference in BUT at any time. Comparing scores before and after treatment, the acupuncture and SSP groups showed a significant improvement compared to the control group. The acupuncture group showed a greater 8-week improvement in Schirmer tests scores compared to the SSP group. However, the SSP group patients used fewer applications of artificial tears. Acupuncture and SSP electro-therapy were effective in increasing tear secretion in patients with dry eye syndrome. The SSP electro-therapy not only alleviated dry eye syndrome, but also reduced the number of applications of artificial tears necessary.

scholarly journals Comparative Effectiveness of Simulation versus Serious Game for Training Nursing Students in Cardiopulmonary Resuscitation: A Randomized Control Trial

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zahra Farsi ◽  
Mahdieh Yazdani ◽  
Samantha Butler ◽  
Maryam Nezamzadeh ◽  
Jila Mirlashari
Keyword(s):  
Nursing Students ◽  
Cardiopulmonary Resuscitation ◽  
Randomized Control Trial ◽  
Serious Game ◽  
Control Group ◽  
Training Groups ◽  
Significant Difference ◽  
Randomized Control ◽  
The Difference ◽  
Cpr Training

Background. The proper implementation of cardiopulmonary resuscitation (CPR) is crucial in saving patients. Purpose. This study was aimed at evaluating the difference in educating nursing students on CPR when using the traditional simulation training with a mannequin versus a more novel serious game training on the smartphone platform. Methods. This randomized control trial was conducted in 2018-2019. Through purposive sampling, 56 nursing students were selected and randomly assigned to three groups: a simulation-based CPR training, CPR training using a serious game on the smartphone platform, and a control group that received no CPR training. Each student was evaluated pre- and posttraining on CPR knowledge and skill. Results. Both the simulation and serious game training groups increased CPR abilities two weeks after training. The control group did not show improvement in skill or knowledge of CPR. The simulation and serious game intervention groups demonstrated better scores on the knowledge questionnaire and on the CPR skill demonstration in comparison to the control group. However, the simulation group and the serious game group showed no significant difference in knowledge ( 9.55 ± 2.81 vs. 7.77 ± 2.46 ; p = 0.065 ) or CPR skill demonstration ( 27.17 ± 2.81 vs. 25.72 ± 3.98 ; p = 0.988 ). The overall scores for CPR knowledge did not meet minimum expectations (70% score) in either the simulation (47.75%) or serious game (38.85%) group. However, both groups demonstrated adequate CPR skill on demonstration (simulation 87.64% and serious game 83.06%). Conclusions. Both the simulation and serious game training groups were found to increase CPR skill. CPR training would likely benefit from a multimodal approach to education.

scholarly journals THE EFFECTS OF NICOTINE EXPOSURE PER INHALATION TO THE CHANGE OF MOTILITY AND MORPHOLOGY OF THE RAT’S SPERM

2019 ◽  
Vol 26 (2) ◽  
Author(s):  
Puruhito Eko Nugroho ◽  
Fikri Rizaldi ◽  
Wahjoe Djati Soesanto
Keyword(s):  
Wistar Rats ◽  
Male Rats ◽  
Control Group ◽  
Nicotine Exposure ◽  
Motile Sperm ◽  
Normal Morphology ◽  
Sperm Analysis ◽  
Treatment Groups ◽  
Male Wistar Rats ◽  
The Difference

Objective: Smoking are known to have detrimental effect on sperm. The effects are suspiciously come from nicotine as its main pharmacologic component. This study is carried out to analyze the effect of nicotine exposure per inhalation to the difference of motile sperm percentage and normal morphology sperm percentage of male wistar rats. Material & Methods: Thirty male rats were used for this research. They were randomly divided into 5 groups and treated with nicotine inhalation 0.5 mg/kgBW,  1 mg/kgBW, 2 mg/kgBW and 4 mg/kgBW for 30 days while the control rats were not given any treatment. At the end of experiment, sperm analysis was carried out to measure the percentage of motile sperm and percentage of sperm with normal morphology. Results: Percentage of motile sperm significantly decreased (p<0.05) in all treatment groups compared to control group. Comparison between treatment groups revealed that the percentage of motile sperm significantly decreased in 0.5 mg/kgBW vs 2 mg/kgBW, 0.5 mg/kgBW vs 4 mg/kgBW, and 1 mg/kgBW vs 4 mg/kgBW. Percentage of normal morphology sperm decreased significantly (p<0.05) in 1 mg/kgBW, 2 mg/kgBW, and 4 mg/kgBW compared to control groups. Comparison between treatment groups revealed that there were no significant decreased between each treatment groups. Conclusion: This research conclude that nicotine exposure per inhalation can deteriorate the percentage of motile sperm and the percentage of normal morphology sperm of male wistar rats.

Sign in / Sign up

Export Citation Format

Share Document