Detecting trends in body size: empirical and statistical requirements for intraspecific analyses

Abstract Attributing biological explanations to observed ecogeographical and ecological patterns require eliminating potential statistical and sampling artifacts as alternative explanations of the observed patterns. Here, we assess the role of sample size, statistical power, and geographic inclusivity on the general validity and statistical significance of relationships between body size and latitude for 3 well-studied species of turtles. We extend those analyses to emphasize the importance of using statistically robust data in determining macroecological patterns. We examined intraspecific trends in body size with latitude in Chelydra serpentina, Chrysemys picta, and Trachemys scripta using Pearson’s correlations, diagnostic tests for influential points, and resampling. Existing data were insufficient to ascertain a latitudinal trend in body size for C. serpentina or T. scripta. There was a significant relationship for C. picta, however, resampling analyses show that, on average, 16 of the 23 available independent populations were needed to demonstrate a significant relationship and that at least 20 of 23 populations were required to obtain a statistically powerful correlation between body size and latitude. Furthermore, restricting the latitudes of populations resampled shows that body size trends of C. picta were largely due to leveraging effects of populations at the edge of the species range. Our results suggest that broad inferences regarding ecological trends in body size should be made with caution until underlying (intraspecific) patterns in body size can be statistically and conclusively demonstrated.

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Host and environmental correlates of body size in ticks (Acari: Argasidae and Ixodidae)

Canadian Journal of Zoology ◽

10.1139/z98-020 ◽

1998 ◽

Vol 76 (5) ◽

pp. 925-930 ◽

Cited By ~ 10

Author(s):

Robert Poulin

Keyword(s):

Body Size ◽

Significant Relationship ◽

Statistical Power ◽

Environmental Temperature ◽

Effect Of Temperature ◽

Tick Size ◽

Environmental Correlates ◽

Phylogenetically Independent Contrasts ◽

Using Data ◽

Host Body Mass

To evaluate the influence of host mass and environmental temperature on the evolution of body size in ticks, a comparative analysis was performed using data from 193 species. Using the 20 possible phylogenetically independent contrasts among tick species, no relationship was found between body size of female ticks and either host mass or temperature. The statistical power of these analyses was low. Within the two most speciose genera of soft ticks, however, separate cross-species analyses revealed a positive and highly significant relationship between female tick size and host mass. Also, within the two most speciose genera of hard ticks, cross-species analyses showed a positive and highly significant relationship between scutum size of female ticks and host mass. The latter correlation is based on measurements of tick body size that are independent of the level of blood engorgement. No effect of temperature was observed in the within-genera analyses. These within-genera trends may be artefacts of unknown phylogenetic relationships. Another explanation, however, is that host body mass may have influenced the evolution of tick body size.

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Effect of human galanin on the response of circulating catecholamines to hypoglycemia in man

Acta Endocrinologica ◽

10.1530/eje.0.1330723 ◽

1995 ◽

Vol 133 (6) ◽

pp. 723-728 ◽

Cited By ~ 4

Author(s):

Ettore C degli Uberti ◽

Maria R Ambrosio ◽

Marta Bondanelli ◽

Giorgio Transforini ◽

Alberto Valentini ◽

...

Keyword(s):

Heart Rate ◽

Healthy Subjects ◽

Sympathetic Nerve Activity ◽

Heart Rate Response ◽

Statistical Significance ◽

Inhibitory Effect ◽

Amino Acid Residues ◽

Nerve Activity ◽

Receptor Stimulation

degli Uberti EC, Ambrosio MR, Bondanelli M, Trasforini G, Valentini A, Rossi R, Margutti A, Campo M. Effect of human galanin on the response of circulating catecholamines to hypoglycemia in man. Eur J Endocrinol 1995;133:723–8. ISSN 0804–4643 Human galanin (hGAL) is a neuropeptide with 30 amino acid residues that has been found in the peripheral and central nervous system, where it often co-exists with catecholamines. In order to clarify the possible role of hGAL in the regulation of sympathoadrenomedullary function, the effect of a 60 min infusion of hGAL (80 pmol·kg−1 · min−1) on plasma epinephrine and norepinephrine responses to insulin-induced hypoglycemia in nine healthy subjects was investigated. Human GAL administration significantly reduced both the release of basal norepinephrine and the response to insulin-induced hypoglycemia, whereas it attenuated the epinephrine response by 26%, with the hGAL-induced decrease in epinephrine release failing to achieve statistical significance. Human GAL significantly increased the heart rate in resting conditions and clearly exaggerated the heart rate response to insulin-induced hypoglycemia, whereas it had no effect on the blood pressure. We conclude that GAL receptor stimulation exerts an inhibitory effect on basal and insulin-induced hypoglycemia-stimulated release of norepinephrine. These findings provide further evidence that GAL may modulate sympathetic nerve activity in man but that it does not play an important role in the regulation of adrenal medullary function. Ettore C degli Uberti, Chair of Endocrinology, University of Ferrara, Via Savonarola 9, I-44100 Ferrara, Italy

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Exploring power in response inhibition tasks using the bootstrap: The impact of number of participants, number of trials, effect magnitude, and study design

10.31234/osf.io/eb4jd ◽

2019 ◽

Cited By ~ 1

Author(s):

Curtis David Von Gunten ◽

Bruce D Bartholow

Keyword(s):

Study Design ◽

Effect Size ◽

Statistical Power ◽

Bootstrap Sampling ◽

Reliable Measure ◽

Internal Reliability ◽

The Impact ◽

Power Analyses ◽

Effect Magnitude

A primary psychometric concern with laboratory-based inhibition tasks has been their reliability. However, a reliable measure may not be necessary or sufficient for reliably detecting effects (statistical power). The current study used a bootstrap sampling approach to systematically examine how the number of participants, the number of trials, the magnitude of an effect, and study design (between- vs. within-subject) jointly contribute to power in five commonly used inhibition tasks. The results demonstrate the shortcomings of relying solely on measurement reliability when determining the number of trials to use in an inhibition task: high internal reliability can be accompanied with low power and low reliability can be accompanied with high power. For instance, adding additional trials once sufficient reliability has been reached can result in large gains in power. The dissociation between reliability and power was particularly apparent in between-subject designs where the number of participants contributed greatly to power but little to reliability, and where the number of trials contributed greatly to reliability but only modestly (depending on the task) to power. For between-subject designs, the probability of detecting small-to-medium-sized effects with 150 participants (total) was generally less than 55%. However, effect size was positively associated with number of trials. Thus, researchers have some control over effect size and this needs to be considered when conducting power analyses using analytic methods that take such effect sizes as an argument. Results are discussed in the context of recent claims regarding the role of inhibition tasks in experimental and individual difference designs.

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Highly sensitive adolescent benefits in positive school transitions: Evidence for vantage sensitivity in Japanese high-schoolers

10.31234/osf.io/kmxqs ◽

2020 ◽

Author(s):

Shuhei Iimura

Keyword(s):

High School ◽

Statistical Power ◽

Environmental Influences ◽

Differential Susceptibility ◽

School Transition ◽

Well Being ◽

Crossover Point ◽

Japanese Adolescents ◽

Highly Sensitive

Some researchers indicate that the transition to high school deflects adolescent developmental trajectories. Others assert it provides a new possibility for the promotion of adolescents’ socioemotional well-being. One critical view missing in such claims is that individual variabilities interact with environmental influences. We employed the framework of Differential Susceptibility Theory, which postulates that individual susceptibilities moderate external influences for better and for worse. In order to clarify the mechanism of adolescents’ differential adjustments, this paper investigated the role of sensory-processing sensitivity using the Japanese version of Highly Sensitive Child Scale for Adolescence (J-HSCS), and tested whether the diathesis-stress model or the differential susceptibility model best describes students’ socioemotional adjustment across their high school transition. The current paper used the two-wave data collected from Japanese adolescents aged from 14 to 15 years (n = 412, 50% girls). In Study 1, we investigated the replicability of psychometric properties of J-HSCS. The results supported previous findings, indicating its validity for the bifactor model. In Study 2, we utilized confirmatory competitive model testing, which maximizes statistical power by parameterizing the crossover point to allow a direct comparison of alternative models. The results indicated that neither the diathesis-stress nor the differential susceptibility models fitted the data. Rather, a strong vantage sensitivity model was revealed, suggesting that highly susceptible adolescents disproportionately benefitted from a positive school transition over their counterparts. This finding signified the role of adolescents’ sensitivity to environmental influences and the importance of considering its moderation under person x environment interactions.

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Effects of High Intensity Statin Therapy in the Treatment of Diabetic Dyslipidemia in Patients with Coronary Artery Disease

Current Pharmaceutical Design ◽

10.2174/1381612824666171227215708 ◽

2018 ◽

Vol 24 (4) ◽

pp. 427-441 ◽

Cited By ~ 2

Author(s):

Marija Vavlukis ◽

Sasko Kedev

Keyword(s):

Statin Therapy ◽

High Intensity ◽

Statistical Significance ◽

Incident Diabetes ◽

Moderate Intensity ◽

Protective Effects ◽

Pcsk9 Inhibitors ◽

Diabetic Dyslipidemia ◽

Patients With Diabetes

Background: Diabetic dyslipidemia has specifics that differ from dyslipidemia in patients without diabetes, which contributes to accelerated atherosclerosis equally as dysglycemia. The aim of this study was to deduce the interdependence of diabetic dyslipidemia and cardiovascular diseases (CVD), therapeutic strategies and the risk of diabetes development with statin therapy. Method: We conducted a literature review of English articles through PubMed, PubMed Central and Cochrane, on the role of diabetic dyslipidemia in atherosclerosis, the antilipemic treatment with statins, and the role of statin therapy in newly developed diabetes, by using key words: atherosclerosis, diabetes mellitus, diabetic dyslipidemia, CVD, statins, nicotinic acid, fibrates, PCSK9 inhibitors. Results: hyperglycemia and dyslipidemia cannot be treated separately in patients with diabetes. It seems that dyslipidemia plays one of the key roles in the development of atherosclerosis. High levels of TG, decreased levels of HDL-C and increased levels of small dense LDL- C particles in the systemic circulation are the most specific attributes of diabetic dyslipidemia, all of which originate from an inflated flux of free fatty acids occurring due to the preceding resistance to insulin, and exacerbated by elevated levels of inflammatory adipokines. Statins are a fundamental treatment for diabetic dyslipidemia, both for dyslipidemia and for CVD prevention. The use of statin treatment with high intensity is endorsed for all diabetes-and-CVD patients, while a moderate - intensity treatment can be applied to patients with diabetes, having additional risk factors for CVD. Statins alone are thought to possess a small, although of statistical significance, risk of incident diabetes, outweighed by their benefits. Conclusion: As important as hyperglycemia and glycoregulation are in CVD development in patients with diabetes, diabetic dyslipidemia plays an even more important role. Statins remain the cornerstone of antilipemic treatment in diabetic dyslipidemia, and their protective effects in CVD progression overcome the risk of statin- associated incident diabetes.

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Do we Need Maintenance Chemotherapy in Advanced NSCLC in the Era of Immune and Targeted Therapy?

Current Cancer Therapy Reviews ◽

10.2174/1573394714666180417160205 ◽

2019 ◽

Vol 15 (1) ◽

pp. 50-55

Author(s):

Ahmed Nagy ◽

Omar Abdel Rahman ◽

Heba Abdullah ◽

Ahmed Negida

Keyword(s):

Lung Cancer ◽

Maintenance Therapy ◽

Small Cell Lung Cancer ◽

Cell Lung Cancer ◽

Statistical Significance ◽

Small Cell ◽

Maintenance Chemotherapy ◽

Small Cell Lung ◽

The Impact

Background: Although well established for the effective management of hematologic cancers, maintenance chemotherapy has only been recently incorportated as a treatment paradigm for advanced non–small-cell lung cancer. Maintenance chemotherapy aims to prolong a clinically favorable response state achieved after finishing induction therapy which is usually predefined in number before startng treatment. There are 2 modalities for maintenance therapy; continuation maintenance (involving a non-platinum component which was a part of the induction protocol or a targeted agent) and switch maintenance therapy (utilizing a new agent which was not a part of the induction regimen). Methods: The purpose of this article is to review the role of maintenance therapy in the treatment of advanced Non-Small Cell Lung Cancer (NSCLC) and provide a brief overview about induction chemotherapy in NSCLC to address the basis of maintenance therapy as a treatment option. We will also compare the impact of maintenance chemotherapy with the now evolving role of immunotherapy in NSCLC. Results: There have been 4 maintenance studies to date showing prolonged PFS and OS with statistical significance. However, Three out of the four studies (ECOG4599, JMEN, and PARAMOUNT) did not report tumor molecular analysis. As regard Immunotherapy, current data is in favour of strongly an increasing role for immunotherapy in NSCLC. Conclusion: Maintenance therapy in NSCLC continues to be an important therapeutic line to improve outcome in patients with metastatic and recurrent disease.

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The Role of Family and Friends in Return Migration and Its Labor Market Outcomes

Population Research and Policy Review ◽

10.1007/s11113-021-09650-x ◽

2021 ◽

Author(s):

Brian Joseph Gillespie ◽

Clara H. Mulder ◽

Christiane von Reichert

Keyword(s):

Labor Market ◽

Survey Data ◽

Significant Relationship ◽

Return Migration ◽

Labor Market Outcomes ◽

Age Groups ◽

Market Outcomes ◽

Market Stability ◽

Onward Migration

AbstractDrawing on survey data on individuals’ motives for migration in Sweden (N = 2172), we examine the importance of family and friends for return versus onward migration, including their importance for different age groups and in different communities on the rural–urban spectrum. The results point to a significant relationship between the importance of family and return versus onward migration, with family importance decreasing with age among returning migrants. At the same time, the importance of friends for returning increases with age. The findings did not suggest a significant relationship between urbanicity and returning versus migration elsewhere. Based on a subset of respondents who were employed prior to migrating (n = 1056), we further examined labor market outcomes for onward versus returning migrants. The results broadly indicate that return migrations are linked to lower likelihoods of labor market deterioration and improvement, suggesting greater labor market stability for return vis-à-vis onward migrations. However, the importance of family for returning (versus moving elsewhere) is associated with higher likelihoods of labor market deterioration and improvement compared with staying the same, indicating greater volatility in labor market outcomes when the importance of family is considered.

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The role of developmental rate, body size, and positional behavior in the evolution of covariation and evolvability in the cranium of strepsirrhines and catarrhines

Journal of Human Evolution ◽

10.1016/j.jhevol.2020.102941 ◽

2021 ◽

Vol 151 ◽

pp. 102941

Author(s):

Catalina I. Villamil

Keyword(s):

Body Size ◽

Developmental Rate ◽

Positional Behavior

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Chemotherapy alone versus definitive concurrent chemoradiotherapy for cT4b esophageal squamous cell carcinoma: a population-based study

BMC Gastroenterology ◽

10.1186/s12876-021-01742-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Chia-Chin Li ◽

Chih-Yi Chen ◽

Ying-Hsiang Chou ◽

Chih-Jen Huang ◽

Hsiu-Ying Ku ◽

...

Keyword(s):

Squamous Cell Carcinoma ◽

Esophageal Squamous Cell Carcinoma ◽

Cell Carcinoma ◽

Squamous Cell ◽

Concurrent Chemoradiotherapy ◽

Statistical Significance ◽

Treatment Options ◽

Population Based ◽

Primary Analysis

Abstract Background The role of radiotherapy for cT4bNanyM0 esophageal squamous cell carcinoma (ESqCC) is relatively unclear, with both chemotherapy (C/T) alone and definitive concurrent chemoradiotherapy (dCCRT) being treatment options in the current guidelines. We aimed to compare the survival of dCCRT versus C/T for these patients via a population-based approach. Methods Eligible cT4b ESqCC patients diagnosed between 2011 and 2017 were identified via the Taiwan Cancer Registry. We used propensity score (PS) weighting to balance the observable potential confounders between groups. The hazard ratio (HR) of death and incidence of esophageal cancer mortality (IECM) were compared between dCCRT and C/T. We also evaluated OS in subgroups of either low or standard radiotherapy doses. Results Our primary analysis consisted of 247 patients in whom covariates were well balanced after PS weighing. The HR for death when dCCRT was compared with C/T was 0.36 (95% confidence interval 0.24–0.53, P < 0.001). Similar results were found for IECM. Statistical significance was only observed in the standard RT dose but not in the low dose in subgroup analyses. Conclusions In this population-based nonrandomized study of cT4bNanyM0 ESqCC patients from Asia (Taiwan), we found that the use of radiotherapy with chemotherapy was associated with better overall survival than chemotherapy alone. Further studies (especially RCTs) are needed to confirm our findings.

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