scholarly journals Residual action of insecticides to larvae of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) under greenhouse conditions

2003 ◽  
Vol 27 (4) ◽  
pp. 835-839 ◽  
Author(s):  
Denilson Bezerra Costa ◽  
Brígida Souza ◽  
Geraldo Andrade Carvalho ◽  
César Freire Carvalho
Keyword(s):  
Experimental Design ◽  
Cotton Plants ◽  
Residual Action

ABSTRACT - This work was designed to evaluate the residual action of the insecticides trichlorfon, triflumuron, endosulfan, fenpropathrin, chlorpirifos, tebufenozide and esfenvalerate, sprayed on cotton plants, to second-instar larvae of Chrysoperla externa (Hagen, 1861), under greenhouse conditions. The experimental design was completely randomized with ten replicates. Three larvae were released on each plant, in the 1st, 12th and 23rd day after pesticides spray. Tebufenozide and esfenvalerate were little persistent (class one), while trichlorfon, triflumuron and endosulfan were slightly persistent, decreasing the survival of C. externa larvae over 30%, up to 14 days after spray. Fenpropathrin and chlorpirifos caused mortality over 30%, up to 25 days after spray, being classified as fairly persistent.

scholarly journals Efeito de subdoses de 2,4-D sal colina na eficiência quântica do fotossistema II do algodoeiro

2020 ◽  
Vol 16 (2) ◽  
pp. 60-71
Keyword(s):  
Experimental Design ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Average Rate ◽  
Yield Potential ◽  
Phenological Stages ◽  
Cotton Plants ◽  
Randomized Experimental Design ◽  
Kinetics Of ◽  
Salt Formulation

Deleterious effects of herbicides on the photochemical apparatus of plants can be quantified by studying the quantum yield potential of photosystem II (Fv/Fm). Therefore, the objective of this work was to evaluate the effect of subdoses of the herbicide 2,4-D choline salt formulation on the quantum efficiency of the photosystem II of cotton plantsat different phenological stages. The study adopted a completely randomized experimental design with seven replications, and the treatments consisted of nine fractions of the average rate indicated on the 2,4-D choline salt herbicide label: 0 (control); 0.4275; 0.855; 1.71; 3.42; 8.55; 17.1; 34.2 and 68.4 g ae ha-1applied at phenological stages V4 or B4 of cotton plants. The plants were evaluated for the visual symptoms of injury and the emission kinetics of maximum chlorophyll a (Fv/Fm) fluorescence at 3, 7 and 14 days after application (DAA) of the herbicide. The values obtained were analyzed by the F test and the effects of the treatments were compared by the Scott-Knott test at 5% probability. The data obtained from visual injury and Fv/Fmwere also submitted to Pearson's correlation. The correlation between visual injury and Fv/Fmin the V4 and B4 stages is negative and significant for both years of conducting the experiment. The Fv/Fmvariable was not affected by the application of subdoses lower than 3.42 g aeha-1of 2,4-D saline choline in the V4 stage and below 1.71 g aeha-1in the B4 stage of the cotton plant.

scholarly journals PRODUCTION OF COTTON PLANTS USING DRIP IRRIGATION IN TWO DIFFERENT PLANTING YEARS

Agric ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 117-124
Author(s):  
Syahruni Thamrin ◽  
Junaedi Junaedi ◽  
H Baso Darwisah
Keyword(s):  
Experimental Design ◽  
Water Availability ◽  
Drip Irrigation ◽  
Field Experiments ◽  
Irrigation Systems ◽  
South Sulawesi ◽  
Cotton Plants ◽  
Dry Conditions ◽  
Number Of Leaves ◽  
Germination And Growth

Cotton plants require sufficient water availability, especially during germination and growth and dry conditions at harvest. In drip irrigation, irrigation can be adjusted to the water needs of each type of plant that varies depending on the growth phase and the type of plant. The study aims to determine the growth and production of cotton plants that use drip irrigation systems in two different planting seasons. The study was conducted for 2 (two) consecutive years, the first study: planting using drip irrigation was carried out in August 2017 and continued with the second planting in May 2018. The research was conducted in Turucinnae Village, Lamuru District, Bone Regency, South Sulawesi Province. The research was carried out in the form of field experiments in the form of a demonstration plot using an experimental design and analysis carried out to find out and explain the implementation of drip irrigation in two different planting seasons. Vegetative growth of cotton plants that use drip irrigation in 2017 provides better results than in 2018 seen from plant height and number of leaves, while the production of cotton plants using drip irrigation in 2017 is greater than that planted in 2018 in terms of the number of bolls. Formed and weight of cotton produced.

scholarly journals Boron-zinc interaction in the absorption of micronutrients by cotton

2018 ◽  
Vol 36 (1) ◽  
pp. 51-57
Author(s):  
Érica De Oliveira Araújo ◽  
Elcio Ferreira Dos Santos ◽  
Marcos Antonio Camacho
Keyword(s):  
Experimental Design ◽  
Nutrient Solution ◽  
Absorption Efficiency ◽  
Transport Efficiency ◽  
Cu Content ◽  
Fe Content ◽  
Cotton Plants ◽  
Fe And Mn ◽  
Randomized Experimental Design ◽  
Mn Content

B-Zn interaction modifies the nutritional dynamics of copper (Cu), iron (Fe) and manganese (Mn) in cotton. The main objective of this research was to evaluate the effect of B and Zn concentrations on the absorption of Cu, Fe and Mn in cotton plants grown in a nutrient solution. A completely randomized experimental design with three replicates was performed, in a 4×5 factorial scheme, corresponding to four concentrations of B (0, 20, 40 and 80 μM L-1) and five concentrations of Zn (0, 1, 2, 4 and 8 μM L-1). At 115 days after emergence, the plants were collected, divided into roots, shoots and fruits, and chemically analyzed. The results allowed to conclude that the Cu content and total Cu in the fruit, total Cu in the roots, Cu efficiency, Fe content in the roots, Fe absorption efficiency, Mn content in the fruit, and Mn absorption efficiency of cotton are influenced by the concentrations of B in the solution. The interaction between B and Zn affected the total Fe in the roots, Fe content and total Fe content in the fruit, Fe transport efficiency, total Mn in the shoots and Mn transport efficiency. In addition, Zn acts differently according to the supply of B and vice versa. 

Identifying suboptimalities with factorial model comparison

2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma
Keyword(s):  
Experimental Design ◽  
Model Comparison ◽  
Process Models ◽  
Multiple Forms ◽  
Factorial Experimental Design ◽  
Factorial Model ◽  
Multiple Components ◽  
The Many

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.

Combining integrated systems-biology approaches with intervention-based experimental design provides a higher-resolution path forward for microbiome research

2019 ◽  
Vol 42 ◽  
Author(s):  
J. Alfredo Blakeley-Ruiz ◽  
Carlee S. McClintock ◽  
Ralph Lydic ◽  
Helen A. Baghdoyan ◽  
James J. Choo ◽  
...  
Keyword(s):  
Systems Biology ◽  
High Resolution ◽  
Experimental Design ◽  
Integrated Systems ◽  
Microbiome Research ◽  
Constructive Criticism

Abstract The Hooks et al. review of microbiota-gut-brain (MGB) literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: (a) highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and (b) recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.

Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

Using Video Modeling Intervention and Speech Generating Devices To Teach Requesting Behaviors to Persons With Autism

2011 ◽  
Vol 20 (4) ◽  
pp. 109-113
Author(s):  
Karen Copple ◽  
Rajinder Koul ◽  
Devender Banda ◽  
Ellen Frye
Keyword(s):  
Developmental Disabilities ◽  
Experimental Design ◽  
Communication Skills ◽  
Observational Learning ◽  
Video Modeling ◽  
Single Subject ◽  
Design Studies ◽  
Communicative Behaviors ◽  
Speech Generating Device ◽  
Treatment Package

Abstract One of the instructional techniques reported in the literature to teach communication skills to persons with autism is video modeling (VM). VM is a form of observational learning that involves watching and imitating the desired target behavior(s) exhibited by the person on the videotape. VM has been used to teach a variety of social and communicative behaviors to persons with developmental disabilities such as autism. In this paper, we describe the VM technique and summarize the results of two single-subject experimental design studies that investigated the acquisition of spontaneous requesting skills using a speech generating device (SGD) by persons with autism following a VM intervention. The results of these two studies indicate that a VM treatment package that includes a SGD as one of its components can be effective in facilitating communication in individuals with autism who have little or no functional speech.

Nepotism in the Hiring of Leaders

2014 ◽  
Vol 73 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Annick Darioly ◽  
Ronald E. Riggio
Keyword(s):  
Experimental Design ◽  
Perceived Competence ◽  
Negative Evaluation ◽  
Leadership Position ◽  
Family Ties ◽  
Hiring Decision ◽  
Job Application ◽  
Career Progress

This study examines how applicants who are relatives of the company’s executives are perceived when they are being considered for a leadership position. In a 2 (Family ties: with vs. without) × 2 (Applicant qualifications: well-qualified vs. underqualified) experimental design, 165 Swiss employees read the applicant’s job application and evaluated the hiring decision, the perceived competence, and the perceived career progress of the target employee. This research showed that even a well-qualified potential employee received a more negative evaluation if the candidate had family ties to the company. Despite their negative evaluation of potential nepotistic hires, the participants nevertheless believed that family ties would boost the career progress of an underqualified applicant. Limitations and implications are discussed.

A Pilot Study on the Efficacy of Volunteer Mentorship for Young Adults With Self-Harm Behaviors Using a Quasi-Experimental Design

Crisis ◽  
2016 ◽  
Vol 37 (6) ◽  
pp. 415-426 ◽  
Author(s):  
Yik-Wa Law ◽  
Paul S. F. Yip ◽  
Carmen C. S. Lai ◽  
Chi Leung Kwok ◽  
Paul W. C. Wong ◽  
...  
Keyword(s):  
Experimental Design ◽  
Suicide Ideation ◽  
Intervention Group ◽  
Well Being ◽  
Control Group ◽  
Treatment As Usual ◽  
Prevention Services ◽  
Quasi Experimental ◽  
Self Harm ◽  
Volunteer Support

Abstract. Background: Studies have shown that postdischarge care for self-harm patients is effective in reducing repeated suicidal behaviors. Little is known about whether volunteer support can help reduce self-harm repetition and improve psychosocial well-being. Aim: This study investigated the efficacy of volunteer support in preventing repetition of self-harm. Method: This study used a quasi-experimental design by assigning self-harm patients admitted to the emergency departments to an intervention group with volunteer support and treatment as usual (TAU) for 9 months and to a control group of TAU. Outcome measures include repetition of self-harm, suicidal ideation, hopelessness, and level of depressive and anxiety symptoms. Results: A total of 74 cases were recruited (38 participants; 36 controls). There were no significant differences in age, gender, and clinical condition between the two groups at the baseline. The intervention group showed significant improvements in hopelessness and depressive symptoms. However, the number of cases of suicide ideation and of repetition of self-harm episodes was similar for both groups at the postintervention period. Conclusion: Postdischarge care provided by volunteers showed significant improvement in hopelessness and depression. Volunteers have been commonly involved in suicide prevention services. Further research using rigorous methods is recommended for improving service quality in the long term.

Everybody Follows the Crowd?

2017 ◽  
Vol 29 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Magdalena Obermaier ◽  
Thomas Koch ◽  
Christian Baden
Keyword(s):  
Experimental Design ◽  
News Coverage ◽  
Personal Characteristics ◽  
Election Campaigns ◽  
Bandwagon Effect ◽  
Political News ◽  
Election Results ◽  
Opinion Polls ◽  
Electoral Preferences

Abstract. Opinion polls are a well-established part of political news coverage, especially during election campaigns. At the same time, there has been controversial debate over the possible influences of such polls on voters’ electoral choices. The most prominent influence discussed is the bandwagon effect: It states that voters tend to support the expected winner of an upcoming election, and use polls to determine who the likely winner will be. This study investigated the mechanisms underlying the effect. In addition, we inquired into the role of past electoral performances of a candidate and analyzed how these (as well as polls) are used as heuristic cues for the assessment of a candidate’s personal characteristics. Using an experimental design, we found that both polls and past election results influence participants’ expectations regarding which candidate will succeed. Moreover, higher competence was attributed to a candidate, if recipients believe that the majority of voters favor that candidate. Through this attribution of competence, both information about prior elections and current polls shaped voters’ electoral preferences.

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