scholarly journals Reliability of size-selectivity estimates from paired-trawl and covered-codend experiments

2009 ◽  
Vol 67 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Russell B. Millar
Keyword(s):  
Statistical Analysis ◽  
Standard Error ◽  
Statistical Error ◽  
Sampling Effort ◽  
Marine Science ◽  
Size Selectivity ◽  
Experimental Conditions ◽  
Complex Statistical Analysis ◽  
And Control ◽  
Statistical Variability

Abstract Millar, R. B. 2010. Reliability of size-selectivity estimates from paired-trawl and covered-codend experiments. – ICES Journal of Marine Science, 67: 530–536. To determine the size selectivity of a trawl codend from sea trials, the researcher must choose between using paired (experimental and control) and covered-codend gears. The paired-gear method has the advantage that the experimental codend can be deployed without modification, but has the disadvantage of a more complex statistical analysis. It has previously been claimed that this analysis is inherently biased regardless of sampling effort. This claim is shown to be erroneous, and it is seen that both methods produce estimators that have negligible bias under typical experimental conditions. However, paired-gear analyses were seen to produce estimators having greater statistical variability than the covered-codend analyses. Over the range of simulations employed herein, it was found that the paired-gear method generally had moderately higher (ratio of 1.3–1.9) statistical error for estimation of the length of 50% retention, when fished with equal sampling effort as the covered-codend gear. Paired-gear estimates of the selection range could have considerably higher standard error than covered-codend estimates (ratio of 1.6–4.2), with the highest ratio being for a scenario where the selection curve was asymmetric and sampling effort consisted of ten replicate deployments where the number of measured fish was restricted to 250.

Recidivism Reduction Research

2020 ◽  
pp. 15-23
Keyword(s):  
Statistical Analysis ◽  
20Th Century ◽  
Computer Software ◽  
Control Group ◽  
Probation And Parole ◽  
What Works ◽  
Research Designs ◽  
Complex Statistical Analysis ◽  
And Control ◽  
Second Chance

Since 2009, more than 840 Second Chance Act grant awards have been made to government and nonprofit agencies, and taxpayers have paid nearly 700 million dollars in Second Chance grants. Additionally, $154 million has been spent on probation and parole supervision agencies and staff through the Justice Reinvestment Initiative. Yet, our probation and parole population continue growing! Given the amount of money taxpayers have invested in programs, it seems nothing works. In the 20th century, it was assumed that the use of randomized and control-group research designs and complex statistical analysis and state-of-the-art computer software would be sufficient to find what “works.” But, we have not yet found what “works.” This chapter asks two questions: 1) Is it the case that “nothing works”? or 2) Is it the case that our research methods can't measure what “works”?

RISK FACTORS FOR THE DEVELOPMENT OF INITIAL MANIFESTATIONS OF ATHEROGENIC CARDIOVASCULAR DISEASES IN PERSONNEL OF CHEMICALLY HAZARDOUS FACILITIES

2017 ◽  
pp. 2-7 ◽  
Author(s):  
V. A. Gorichny ◽  
D. Yu. Serdukov ◽  
A. V. Yazenok ◽  
A. V. Nosov ◽  
G. G. Zagorodnikov ◽  
...  
Keyword(s):  
Risk Factors ◽  
Statistical Analysis ◽  
Cardiovascular Diseases ◽  
Organophosphorus Compounds ◽  
Atherogenic Dyslipidemia ◽  
Chemical Weapons ◽  
Analysis Methods ◽  
High Incidence ◽  
And Control ◽  
Statistical Analysis Methods

An outpatient examination of 530 employees engaged in work with chemical weapons related to organophosphorus compounds at chemically hazardous facilities was carried out. Risk factors for the development of cardiovascular diseases of atherogenic etiology among personnel of the facilities were studied in relation to the type of work performed using statistical analysis methods. When assessing the lipidogram, a high incidence of atherogenic dyslipidemia in a group of personnel involved in the storage of chemical weapons was found out in comparison with a group of people engaged in the destruction and control of chemical weapons (73.1 vs 61.2 vs 59.6%, p

scholarly journals Suitability of the Cyclic Voltammetry Measurements and DPPH• Spectrophotometric Assay to Determine the Antioxidant Capacity of Food-Grade Oenological Tannins

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2925 ◽  
Author(s):  
Arianna Ricci ◽  
Giuseppina Paola Parpinello ◽  
Nemanja Teslić ◽  
Paul Andrew Kilmartin ◽  
Andrea Versari
Keyword(s):  
Cyclic Voltammetry ◽  
Colorimetric Assay ◽  
Radical Scavenging ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Experimental Conditions ◽  
Fast Analysis ◽  
Cv Measurements ◽  
And Control ◽  
Analytical Approaches

Twenty commercially available oenological tannins (including hydrolysable and condensed) were assessed for their antiradical/reducing activity, comparing two analytical approaches: The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging spectrophotometric assay and the cyclic voltammetry (CV) electrochemical method. Electrochemical measurements were performed over a −200 mV–500 mV scan range, and integrated anodic currents to 500 mV were used to build a calibration graph with (+)-catechin as a reference standard (linear range: From 0.0078 to 1 mM, R2 = 0.9887). The CV results were compared with the DPPH• assay (expressed as % of radical scavenged in time), showing high correlation due to the similarity of the chemical mechanisms underlying both methods involving polyphenolic compounds as reductants. Improved correlation was observed by increasing the incubation time with DPPH• to 24 h (R2 = 0.925), demonstrating that the spectrophotometric method requires a long-term incubation to complete the scavenging reaction when high-molecular weight tannins are involved; this constraint has been overcome by using instant CV measurements. We concluded that the CV represents a valid alternative to the DPPH• colorimetric assay, taking advantage of fast analysis and control on the experimental conditions and, because of these properties, it can assist the quality control along the supply chain.

scholarly journals How Downward and Upward Comparisons on Facebook Influence Grandiose and Vulnerable Narcissists’ Self-Esteem—A Priming Study

2021 ◽  
Vol 11 (3) ◽  
pp. 39
Author(s):  
Phillip Ozimek ◽  
Hans-Werner Bierhoff ◽  
Elke Rohmann
Keyword(s):  
Social Networking Sites ◽  
Online Survey ◽  
Social Comparisons ◽  
Past Research ◽  
Self Esteem ◽  
Self Report ◽  
Control Group ◽  
Experimental Conditions ◽  
Vulnerable Narcissism ◽  
And Control

Past research showed that social networking sites represent perfect platforms to satisfy narcissistic needs. The present study aimed to investigate how grandiose (GN) and vulnerable narcissism (VN) as well as social comparisons are associated with Facebook activity, which was measured with a self-report on three activity dimensions: Acting, Impressing, and Watching. In addition, the state self-esteem (SSE) was measured with respect to performance, social behavior, and appearance. One hundred and ten participants completed an online survey containing measures of SSE and Facebook activity and a priming procedure with three experimental conditions embedded in a social media context (upward comparison, downward comparison, and control group). Results indicated, as expected, that high VN was negatively associated with SSE on each subscale and the overall score. In addition, it was found that VN, but not GN, displayed positive associations with frequency of Facebook activities. Finally, it was proposed and confirmed that VN in interaction with the priming of downward comparisons negatively affected SSE. The conclusion drawn is that VN represents a key variable for the prediction of self-esteem as well as for the frequency of Facebook activity.

scholarly journals Sonographic Signs of Adenomyosis in Women with Endometriosis Are Associated with Infertility

2021 ◽  
Vol 10 (11) ◽  
pp. 2355
Author(s):  
Dean Decter ◽  
Nissim Arbib ◽  
Hila Markovitz ◽  
Daniel S. Seidman ◽  
Vered H. Eisenberg
Keyword(s):  
Laparoscopic Surgery ◽  
Retrospective Study ◽  
Statistical Analysis ◽  
Conservative Management ◽  
Transvaginal Ultrasound ◽  
Control Group ◽  
Study Group ◽  
Control Groups ◽  
Increased Risk ◽  
And Control

We compared the prevalence of ultrasound signs of adenomyosis in women with endometriosis who underwent surgery to those who were managed conservatively. This was a retrospective study of women evaluated at a tertiary endometriosis referral center who underwent 2D/3D transvaginal ultrasound. Adenomyosis diagnosis was based on the presence of at least three sonographic signs. The study group subsequently underwent laparoscopic surgery while the control group continued conservative management. Statistical analysis compared the two groups for demographics, symptoms, clinical data, and sonographic findings. The study and control groups included 244 and 158 women, respectively. The presence of any, 3+, or 5+ sonographic signs of adenomyosis was significantly more prevalent in the study group (OR = 1.93–2.7, p < 0.004, 95% CI; 1.24–4.09). After controlling for age, for all findings but linear striations, the OR for having a specific feature was higher in the study group. Women in the study group with ≥ 5 sonographic signs of adenomyosis had more than twice the risk of experiencing infertility (OR = 2.31, p = 0.012, 95% CI; 1.20–4.45). Sonographic signs of adenomyosis are more prevalent in women with symptomatic endometriosis who underwent surgery compared with those who continued conservative management. Women with 5+ findings have a significantly increased risk of infertility. Adenomyosis on ultrasound should be considered in the management decisions regarding these patients.

scholarly journals A gradient field defeats the inherent repulsion between magnetic nanorods

2014 ◽  
Vol 1 (2) ◽  
pp. 140271 ◽  
Author(s):  
Yu Gu ◽  
Ruslan Burtovyy ◽  
John Custer ◽  
Igor Luzinov ◽  
Konstantin G. Kornev
Keyword(s):  
Phase Portrait ◽  
High Speed ◽  
Uniform Magnetic Field ◽  
Gradient Field ◽  
Physical Parameters ◽  
Uniform Field ◽  
Experimental Conditions ◽  
Magnetic Nanorods ◽  
Field Gradients ◽  
And Control

When controlling the assembly of magnetic nanorods and chains of magnetic nanoparticles, it is extremely challenging to bring them together side by side while keeping a desired spacing between their axes. We show that this challenge can be successfully resolved by using a non-uniform magnetic field that defeats an inherent repulsion between nanorods. Nickel nanorods were suspended in a viscous film and a non-uniform field was used to control their placement. The in-plane movement of nanorods was tracked with a high-speed camera and a detailed image analysis was conducted to quantitatively characterize the behaviour of the nanorods. The analysis focused on the behaviour of a pair of neighbour nanorods, and a corresponding dynamic model was formulated and investigated. The complex two-dimensional dynamics of a nanorod pair was analysed analytically and numerically, and a phase portrait was constructed. Using this phase portrait, we classified the nanorod behaviour and revealed the experimental conditions in which nanorods could be placed side by side. Dependence of the distance between a pair of neighbour nanorods on physical parameters was analysed. With the aid of the proposed theory, one can build different lattices and control their spacing by applying different field gradients.

scholarly journals Achieving equitable uptake of handwashing and sanitation by addressing both supply and demand-based constraints: findings from a randomized controlled trial in rural Bangladesh

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Sarker Masud Parvez ◽  
Musarrat Jabeen Rahman ◽  
Rashidul Azad ◽  
Mahbubur Rahman ◽  
Leanne Unicomb ◽  
...  
Keyword(s):  
Controlled Trial ◽  
Supply And Demand ◽  
Efficacy Trial ◽  
Experimental Conditions ◽  
Randomized Controlled ◽  
Link Type ◽  
Education Levels ◽  
Change Promotion ◽  
And Control ◽  
The Impact

Abstract Background Supply driven programs that are not closely connected to community demand and demand-driven programs that fail to ensure supply both risk worsening inequity. Understanding patterns of uptake of behaviors among the poorest under ideal experimental conditions, such as those of an efficacy trial, can help identify strategies that could be strengthened in routine programmatic conditions for more equitable uptake. WASH Benefits Bangladesh was a randomized controlled efficacy trial that provided free-of cost WASH hardware along with behavior change promotion. The current paper aimed to determine the impact of the removal of supply and demand constraints on the uptake of handwashing and sanitation behaviors across wealth and education levels. Methods The current analysis selected 4 indicators from the WASH Benefits trial— presence of water and soap in household handwashing stations, observed mother’s hand cleanliness, observed visible feces on latrine slab or floor and reported last child defecation in potty or toilet. A baseline assessment was conducted immediately after enrolment and endline assessment was conducted approximately 2 years later. We compared change in uptake of these indicators including wealth quintiles (Q) between intervention and control groups from baseline to endline. Results For hand cleanliness, the poorest mothers improved more [Q1 difference in difference, DID: 16% (7, 25%)] than the wealthiest mothers [Q5 DID: 7% (− 4, 17%)]. The poorest households had largest improvements for observed presence of water and soap in handwashing station [Q1 DID: 82% (75, 90%)] compared to the wealthiest households [Q5 DID: 39% (30, 50%)]. Similarly, poorer household demonstrated greater reductions in visible feces on latrine slab or floor [Q1DID, − 25% (− 35, − 15) Q2: − 34% (− 44, − 23%)] than the wealthiest household [Q5 DID: − 1% (− 11, 8%). For reported last child defecation in potty or toilet, the poorest mothers showed greater improvement [Q1–4 DID: 50–54% (44, 60%)] than the wealthier mothers [Q5 DID: 39% (31, 46%). Conclusion By simultaneously addressing supply and demand-constraints among the poorest, we observed substantial overall improvements in equity. Within scaled-up programs, a separate targeted strategy that relaxes constraints for the poorest can improve the equity of a program. Trial registration WASH Benefits Bangladesh: ClinicalTrials.gov, identifier: NCT01590095. Date of registration: April 30, 2012 ‘Retrospectively registered’.

A gel-membrane model of glomerular charge and size selectivity in series

2001 ◽  
Vol 280 (3) ◽  
pp. F396-F405 ◽  
Author(s):  
Maria Ohlson ◽  
Jenny Sörensson ◽  
Börje Haraldsson
Keyword(s):  
Negative Charge ◽  
Careful Analysis ◽  
Size Selectivity ◽  
Gel Structure ◽  
Experimental Conditions ◽  
Ion Interactions ◽  
In Series ◽  
A Charge ◽  
Glomerular Barrier

We have analyzed glomerular sieving data from humans, rats in vivo, and from isolated perfused rat kidneys (IPK) and present a unifying hypothesis that seems to resolve most of the conflicting results that exist in the literature. Particularly important are the data obtained in the cooled IPK, because they allow a variety of experimental conditions for careful analysis of the glomerular barrier; conditions that never can be obtained in vivo. The data strongly support the classic concept of a negative charge barrier, but separate components seem to be responsible for charge and size selectivity. The new model is composed of a dynamic gel and a more static membrane layer. First, the charged gel structure close to the blood compartment has a charge density of 35–45 meq/l, reducing the concentration of albumin to 5–10% of that in plasma, due to ion-ion interactions. Second, the size-selective structure has numerous functional small pores (radius 45–50 Å) and far less frequent large pores (radius 75–115 Å), the latter accounting for 1% of the total hydraulic conductance. Both structures are required for the maintenance of an intact glomerular barrier.

scholarly journals In vitro activity of zinc oxide-eugenol and glass ionomer cements on Candida albicans

2005 ◽  
Vol 19 (2) ◽  
pp. 134-138 ◽  
Author(s):  
Anna Carolina Aguiar Cassanho ◽  
Aletéia Massula Fernandes ◽  
Luciane Dias de Oliveira ◽  
Claudio Antonio Talge Carvalho ◽  
Antonio Olavo Cardoso Jorge ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Candida Albicans ◽  
Control Group ◽  
Glass Ionomer ◽  
Experimental Conditions ◽  
Mean Values ◽  
Zinc Oxide Eugenol ◽  
Colony Forming Units ◽  
And Control

The aim of this study was to evaluate in vitro the antimicrobial activity of glass ionomer (GIC) and zinc oxide-eugenol (ZOE) cements against Candida albicans. Standardized GIC and ZOE specimens were maintained in contact with C. albicans suspension (1 <FONT FACE=Symbol>´</FONT> 10(6) cells/ml) at 37°C for 24 h, 48 h or 7 days. A control group without any testing cement was included. After the incubation period, aliquots of 0.1 ml were plated on Sabouraud's agar, and then the number of colonies was counted. The results were expressed as values of logarithms of colony-forming units per milliliter (log CFU/mL) and were analyzed statistically by Kruskal-Wallis ANOVA. After 48 h of incubation, the ZOE group presented no growth of C. albicans. GIC and control groups presented similar mean values at all tested periods. According to the results obtained, it could be concluded that, under the experimental conditions, ZOE cement was more effective in vitro against C. albicans than GIC.

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