linear regression models
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2022 ◽  
Vol 8 ◽  
Sameh Mosaed ◽  
Andrew K. Smith ◽  
John H. K. Liu ◽  
Donald S. Minckler ◽  
Robert L. Fitzgerald ◽  

BackgroundΔ9-tetrahydrocannabinol (THC) has been shown to decreased intraocular pressure (IOP). This project aims to define the relationship between plasma THC levels and IOP in healthy adult subjects.MethodsEleven healthy subjects received a single dose of inhaled cannabis that was self-administered in negative pressure rooms. Measurements of IOP and plasma THC levels were taken at baseline and every 30 min for 1 h and afterwards every hour for 4 h. IOP reduction and percent change in IOP over time were calculated. Linear regression models were used to measure the relationship between IOP and plasma THC levels. Two line linear regression models with F-tests were used to detect change points in the regression. Then, Pearson correlations were computed based on the change point.ResultsTwenty-two eyes met inclusion criteria. The average peak percentage decrease in IOP was 16% at 60 min. Percent IOP reduction as well as total IOP reduction demonstrated a negative correlation with THC plasma levels showing r-values of −0.81 and −0.70, respectively. F-tests revealed a change point in the regression for plasma levels >20 ng/ml. For levels >20 ng/ml, the correlation coefficients changed significantly with r-values of 0.21 and 0.29 (p < 0.01).ConclusionPlasma THC levels are significantly correlated with IOP reduction up to plasma levels of 20 ng/ml. Plasma levels >20 ng/ml were not correlated with further decrease in IOP. More research is needed to determine the efficacy of THC in reducing IOP for eyes with ocular hypertension and glaucoma.

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Lateef Ayodele Agbetunde ◽  
Lukman Raimi ◽  
Olalekan Oladipo Akinrinola

Purpose This paper aims to investigate the moderating influence of religiosity on the effect of taxpaying attitudes on the tax compliance behaviour of entrepreneurial firms in Nigeria. Design/methodology/approach Using a cross-sectional survey design, we collected primary data from 368 owner managers of entrepreneurial firms in Southwest Nigeria using structured questionnaires. Respondents were purposefully selected based on the purposive sampling technique. The data collected with the structured questionnaires were analysed using descriptive and inferential statistics. Two linear regression models were compared. Findings Estimations in Models 1 and 2 suggest that taxpayers’ attitudes and religiosity (intra- and interreligiosity) have significant effects on the tax compliance behaviour of firms, but the influence of intrareligiosity is insignificant. Estimations in Model 3 suggest that taxpaying attitudes without the moderating influence of religiosity exerted a significant effect on tax compliance behaviour by 13%, while taxpaying attitudes with the moderating influence of religiosity exerted 17%. Estimations in Model 4 suggest that taxpaying attitudes with the moderating influence of the interreligiosity dimension had a more significant contribution to the changes in tax compliance behaviour than the intrareligious dimension. Research limitations/implications From the findings, the following policy implications can be deduced: (i) if taxpayers’ attitudes improved and religiosity was leveraged by the tax authorities, tax compliance behaviour of entrepreneurial firms would be induced in Nigeria; (ii) the consistent positive influence is a strong indication that religious values are critical elements of tax compliance interventions that should be considered by policymakers when designing public policies on tax evasion and avoidance in developing countries. Originality/value We bridge the gaps in the literature because our study affirmed that taxes are religiously driven. In addition, the study validates the applicability of theory of planned behaviour in investigating the moderating influence of religiosity on the causality between taxpaying attitude and tax compliance in the developing context.

Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 353
Lucia Alonso-Pedrero ◽  
Carolina Donat-Vargas ◽  
Maira Bes-Rastrollo ◽  
Ana Ojeda-Rodríguez ◽  
Guillermo Zalba ◽  

Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the “Seguimiento Universidad de Navarra” (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = −0.30 × 10−7; 95% CI, −0.55 × 10−7 to −0.06 × 10−7), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = −6.17 × 10−7; 95% CI, −11.30 × 10−7 to −1.03 × 10−7), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = −5.02 × 10−7; 95% CI, −9.44 × 10−7 to −0.61 × 10−7), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = −13.90 × 10−7; 95% CI, −37.70 × 10−7 to 9.79 × 10−7). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 123
María Jaenada ◽  
Leandro Pardo

Minimum Renyi’s pseudodistance estimators (MRPEs) enjoy good robustness properties without a significant loss of efficiency in general statistical models, and, in particular, for linear regression models (LRMs). In this line, Castilla et al. considered robust Wald-type test statistics in LRMs based on these MRPEs. In this paper, we extend the theory of MRPEs to Generalized Linear Models (GLMs) using independent and nonidentically distributed observations (INIDO). We derive asymptotic properties of the proposed estimators and analyze their influence function to asses their robustness properties. Additionally, we define robust Wald-type test statistics for testing linear hypothesis and theoretically study their asymptotic distribution, as well as their influence function. The performance of the proposed MRPEs and Wald-type test statistics are empirically examined for the Poisson Regression models through a simulation study, focusing on their robustness properties. We finally test the proposed methods in a real dataset related to the treatment of epilepsy, illustrating the superior performance of the robust MRPEs as well as Wald-type tests.

2022 ◽  
Vol 2 (1) ◽  
pp. 12-25
Francesca Zanasi ◽  
Gustavo De Santis ◽  
Elena Pirani

Frailty is a complex state of objective and subjective vulnerability. It tends to increase with age, but the process is influenced by previous life course, especially previous disadvantages. The aim of this paper is to examine how the disadvantages suffered in adulthood (25 to 59 years) in four domains (unemployment, financial hardship, stress, and bad health) affect frailty in late adulthood (60 to 79 years). Using linear regression models on data from the Survey of Health, Ageing, and Retirement in Europe (2004–2017), we estimate frailty levels for several age groups (60–64, 65–69, 70–74, 75–79) accounting for both the persistence of these disadvantages over time and their coexistence, i.e., the number of years when they were simultaneously experienced. Results show that while frailty increases with age, as expected, there is also evidence of an accumulation of risks: the longer the periods of adult life affected by unemployment, stress, financial hardship or, most importantly, bad health, the frailer individuals are in their late years. Furthermore, periods of coexisting disadvantages in adulthood translate into additional frailty in late life. Our findings highlight the importance of fighting disadvantages early in life: long-term improvements in terms of reduced frailty (a concept interrelated with health) may be substantial.

2022 ◽  
pp. 073346482110642
Claudia Venturini ◽  
Bruno de Souza Moreira ◽  
Eduardo Ferriolli ◽  
Anita Liberalesso Neri ◽  
Roberto Alves. Lourenço ◽  

The objective is to investigate the mediating roles of living alone and personal network in the relationship between physical frailty and activities of daily living (ADL) limitations among older adults. 2271 individuals were classified as vulnerable (pre-frail or frail) or robust. Mediating variables were living alone and personal network. Katz Index and Lawton-Brody scale were used to assess ADL. Mediating effects were analyzed with beta coefficients from linear regression models using the bootstrapping method. Mediation analysis showed significant mediating effects of living alone (β = .011; 95% CI = .004; .018) and personal network (β = .005; 95% CI = .001; .010) on the relationship between physical frailty and basic ADL limitations. Mediation effects of living alone and personal network on the relationship between physical frailty and instrumental ADL limitations were β = −.074 (95% CI=−.101; −.046) and β = −.044 (95% CI = −.076; −.020), respectively. Physically vulnerable older adults who lived alone or had poor personal network were more dependent on basic and instrumental ADL.

Ildikó Husz ◽  
Marianna Kopasz ◽  
Márton Medgyesi

AbstractSocial workers may play an important role in the implementation of welfare policies targeted at the poor. Their norms, beliefs, and attitudes form local anti-poverty programmes and affect discretionary practices with their clients. Despite this, we know little about how social workers’ exposure to poverty shapes their attitudes towards poverty and their causal attributions for poverty. This study investigates social workers’ poverty explanations and the extent to which they depend on the level of local poverty. Data from a survey conducted among Hungarian social workers were analysed using multilevel linear regression models. To measure local poverty, we used a composite index of poverty, as well as a subjective measure of exposure to poverty. Our analysis revealed that most social workers explained poverty with structural causes, but individual blame was also frequent. Contrary to our hypothesis, the level of local poverty did not significantly increase the adoption of structural explanations but did raise the occurrence of individualistic ones. However, the effect of local poverty was non-linear: social workers tended to blame the poor for their poverty in the poorest municipalities, where multiple disadvantages are concentrated, while moderate poverty did not lead to such opinions. Our results suggest that efforts should be made to improve the poverty indicator framework to better understand the phenomenon of spatial concentration of multiple disadvantages and its consequences for the poor.

Annie Jane Keeney ◽  
Amy Quandt ◽  
Mercy D. Villaseñor ◽  
Daniela Flores ◽  
Luis Flores

Hispanic/Latino and migrant workers experience high degrees of occupational stress, constitute most of California’s agricultural workforce, and were among the most impacted populations by the COVID-19 pandemic. However, relatively little is known about the occupational stress experienced by farmworkers who commute daily between the US and Mexico. Occupational stress is considered an imbalance between the demands at work and the capabilities to respond in the context of the workforce. The goal of this study is to determine the type and severity of stressors in daytime and resident farmworkers and how COVID-19 vaccination status contributes to these stressors. Interviews containing the Migrant Farmworker Stress Inventory (MSWSI) were administered to a sample of 199 Hispanic/Latino farmworkers in Imperial County, a multi-billion-dollar agriculture sector in the US. Principal factor analysis differentiated latent factors in the MFSWI. Simple linear regression models and correlations identified associations between MFWSI scores and sample characteristics. The MFWSI reduced to five stressor domains: Health and Well-Being Vulnerabilities, Inadequate Standards of Living/Unknown Conditions of Living, Working Conditions, Working Environment, and Language Barriers. Approximately 40 percent of the respondents reported significant stress levels, with foreign-born (p = 0.014) and older respondents (p = 0.0415) being more likely to experience elevated stress regardless of their nighttime residence. We found that Spanish-language COVID-19 outreach might have been particularly effective for workers who reported high stress from English-language communication (p = 0.001). Moreover, our findings point to the importance of worker and human rights to mitigate the high-stress foreign-born workers who live in Mexico and the US experience.

2022 ◽  
Thomas Laumon ◽  
Elie Courvalin ◽  
Geoffrey Dagod ◽  
Pauline Deras ◽  
Mehdi Girard ◽  

Abstract Background: Optimal decarboxylation dose under extracorporeal respiratory support to ensure sufficient reduction of mechanical ventilation stress remains unclear and understudied. The aim of this study was to assess the interdependence of blood flow (BF) and gas flow (GF) in predicting CO2 removal and mechanical ventilation reduction (MVR) under extracorporeal respiratory support. Methods: All patients who benefited from veno-venous ECMO (HLS-maquet 7.0, 1.8 m²) and high-flow ECCO2R (HLS-maquet 5.0, 1.3 m²) in our intensive care unit over a period of 18 months were included. CO2 removal was calculated from inlet/outlet blood gases performed in clinical practice during the first 7 days of oxygenator use. The relationship between the BF × GF product and CO2 removal or MVR was studied using linear regression models. Results: Eighteen patients were analysed, corresponding to 24 oxygenators and 261 datasets. CO2 removal was 393 mL/min (IQR, 310–526 mL/min) for 1.8 m2 oxygenators and 179 mL/min (IQR, 165–235 mL/min) for 1.3 m2 oxygenators. The decarboxylation index was associated linearly with CO2 removal (R2 = 0.62 and R2 = 0.77 for the two oxygenators, respectively) and MVR (R2 = 0.72 and R2 = 0.62, respectively). Values in the range 20−30L2/min2 were associated with an MVR ratio between 38% and 58% for 1.8 m2 oxygenators, and between 37% and 55% for 1.3 m2 oxygenators. Conclusion: The decarboxylation index is a simple parameter to predict CO2 removal and MVR under extracorporeal respiratory support. A BF of 2 L2/min2 or more may be necessary to obtain a significant reduction of mechanical convection.Trial Registration: Being a retrospective study, no trial registration was made.

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