Estimates of catchment area of pitfall traps for carabids

Relationships between beetle abundance in the field and data collected from pitfall traps has generated much interest from several generations of carabidologists. Despite the argument and controversy about this relationship, pitfall data remain the main source of knowledge about carabid populations and assemblages in nature. In order to estimate the relationship between pitfall catches of carabids and catchment area in a homogenous deciduous forest, we constructed circular field enclosures of three sizes (radii: 2.5m, 5m and 10m) and sampled carabids using single pitfall traps located in the centre of each enclosure over 3 seasons (2014-2016). We found that overall beetle catches increased linearly with enclosure area during all three years, and the linear models were nearly identical for the two years (2014 and 2016) in which the data were comparable. We then extrapolated the relationship to predict the catchment area using unenclosed traps run simultaneously. For data from both 2014 and 2016, the catchment area for the assemblage is predicted to be 620-640 m2, representing a radius of c. 14.3 m. Interestingly, this value is consistent with the published inter-trap distance required for independence of trap captures at the same site. Unfortunately, but as expected, calibration of pitfall data at the species level is challenging because the best linear model fits vary considerably among species. Trap catchment area also increased during breeding season. Clearly, pitfall traps need to be set at least c. 30 meters apart to ensure independence of samples in mixedwood boreal forest.

Download Full-text

Nutrient – sestonic chlorophyll relationships in northern Ozark streams

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-160 ◽

1999 ◽

Vol 56 (1) ◽

pp. 124-130

Author(s):

Kirk Lohman ◽

John R Jones

Keyword(s):

Catchment Area ◽

Linear Models ◽

Point Sources ◽

Curvilinear Relationship ◽

Running Waters ◽

Nutrient Additions ◽

Row Crop ◽

Catchment Size ◽

The Relationship

We investigated relationships between sestonic chlorophyll (Chl), total phosphorus (TP), and total nitrogen (TN) at 23 sites on 13 streams in the Missouri Ozarks. There was a strong curvilinear relationship between mean sestonic Chl and both mean TP (R2 = 0.78) and mean TN (R2 = 0.70). Both models were improved when catchment area was included with either TP (R2 = 0.90) or TN (R2 = 0.84). Limited to 17 sites without point source nutrient additions, the relationship between sestonic Chl and both TP and TN was linear. Including catchment area strengthened linear models with either TP (R2 = 0.94) or TN (R2 = 0.84). Land use (percent row crop or percent forest), together with catchment size, was also a good predictor of sestonic Chl in Ozark streams without point sources. When catchment area and TP or TN were used to predict sestonic Chl on specific dates following catastrophic flooding, models were less accurate than those based on long-term averages, but still explained 55-74% of the variance in sestonic Chl. Our results demonstrate that sestonic Chl is closely associated with nutrients and catchment area in Ozark streams and that nutrient - sestonic Chl models may have broad application in running waters.

Download Full-text

Analysis of Alaskan burn severity patterns using remotely sensed data

International Journal of Wildland Fire ◽

10.1071/wf06034 ◽

2007 ◽

Vol 16 (3) ◽

pp. 277 ◽

Cited By ~ 65

Author(s):

Paul A. Duffy ◽

Justin Epting ◽

Jonathan M. Graham ◽

T. Scott Rupp ◽

A. David McGuire

Keyword(s):

Boreal Forest ◽

Spatial Correlation ◽

Large Scale ◽

Linear Models ◽

Vegetation Type ◽

Burn Severity ◽

Remotely Sensed Data ◽

Large Scale Disturbance ◽

The Relationship ◽

Complex Landscapes

Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography.

Download Full-text

Assessing Wildfire Burn Severity and Its Relationship with Environmental Factors: A Case Study in Interior Alaska Boreal Forest

Remote Sensing ◽

10.3390/rs13101966 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1966

Author(s):

Christopher W Smith ◽

Santosh K Panda ◽

Uma S Bhatt ◽

Franz J Meyer ◽

Anushree Badola ◽

...

Keyword(s):

Boreal Forest ◽

Ground Truth ◽

Burn Severity ◽

Classification Methods ◽

Spectral Indices ◽

Ground Truth Data ◽

Burn Scar ◽

Interior Alaska ◽

Remote Sensing Methods ◽

The Relationship

In recent years, there have been rapid improvements in both remote sensing methods and satellite image availability that have the potential to massively improve burn severity assessments of the Alaskan boreal forest. In this study, we utilized recent pre- and post-fire Sentinel-2 satellite imagery of the 2019 Nugget Creek and Shovel Creek burn scars located in Interior Alaska to both assess burn severity across the burn scars and test the effectiveness of several remote sensing methods for generating accurate map products: Normalized Difference Vegetation Index (NDVI), Normalized Burn Ratio (NBR), and Random Forest (RF) and Support Vector Machine (SVM) supervised classification. We used 52 Composite Burn Index (CBI) plots from the Shovel Creek burn scar and 28 from the Nugget Creek burn scar for training classifiers and product validation. For the Shovel Creek burn scar, the RF and SVM machine learning (ML) classification methods outperformed the traditional spectral indices that use linear regression to separate burn severity classes (RF and SVM accuracy, 83.33%, versus NBR accuracy, 73.08%). However, for the Nugget Creek burn scar, the NDVI product (accuracy: 96%) outperformed the other indices and ML classifiers. In this study, we demonstrated that when sufficient ground truth data is available, the ML classifiers can be very effective for reliable mapping of burn severity in the Alaskan boreal forest. Since the performance of ML classifiers are dependent on the quantity of ground truth data, when sufficient ground truth data is available, the ML classification methods would be better at assessing burn severity, whereas with limited ground truth data the traditional spectral indices would be better suited. We also looked at the relationship between burn severity, fuel type, and topography (aspect and slope) and found that the relationship is site-dependent.

Download Full-text

The Relationships Between Serum DHEA-S and AMH Levels in Infertile Women: A Retrospective Cross-Sectional Study

Journal of Clinical Medicine ◽

10.3390/jcm10061211 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1211

Author(s):

Li-Te Lin ◽

Kuan-Hao Tsui

Keyword(s):

Generalized Linear Models ◽

Large Scale ◽

Linear Models ◽

Positive Association ◽

Cross Sectional Study ◽

Dehydroepiandrosterone Sulphate ◽

Sectional Study ◽

Cross Sectional ◽

Infertile Women ◽

The Relationship

The relationship between serum dehydroepiandrosterone sulphate (DHEA-S) and anti-Mullerian hormone (AMH) levels has not been fully established. Therefore, we performed a large-scale cross-sectional study to investigate the association between serum DHEA-S and AMH levels. The study included a total of 2155 infertile women aged 20 to 46 years who were divided into four quartile groups (Q1 to Q4) based on serum DHEA-S levels. We found that there was a weak positive association between serum DHEA-S and AMH levels in infertile women (r = 0.190, p < 0.001). After adjusting for potential confounders, serum DHEA-S levels positively correlated with serum AMH levels in infertile women (β = 0.103, p < 0.001). Infertile women in the highest DHEA-S quartile category (Q4) showed significantly higher serum AMH levels (p < 0.001) compared with women in the lowest DHEA-S quartile category (Q1). The serum AMH levels significantly increased across increasing DHEA-S quartile categories in infertile women (p = 0.014) using generalized linear models after adjustment for potential confounders. Our data show that serum DHEA-S levels are positively associated with serum AMH levels.

Download Full-text

Relationship between Cycling Infrastructure and Transportation Cycling in a Small Urban Area

Future Transportation ◽

10.3390/futuretransp1010007 ◽

2021 ◽

Vol 1 (1) ◽

pp. 99-112

Author(s):

Richard Larouche ◽

Nimesh Patel ◽

Jennifer L. Copeland

Keyword(s):

Generalized Linear Models ◽

Qualitative Data ◽

Linear Models ◽

The Other ◽

Small City ◽

The Road ◽

The Past ◽

Low Prevalence ◽

The Relationship

The role of infrastructure in encouraging transportation cycling in smaller cities with a low prevalence of cycling remains unclear. To investigate the relationship between the presence of infrastructure and transportation cycling in a small city (Lethbridge, AB, Canada), we interviewed 246 adults along a recently-constructed bicycle boulevard and two comparison streets with no recent changes in cycling infrastructure. One comparison street had a separate multi-use path and the other had no cycling infrastructure. Questions addressed time spent cycling in the past week and 2 years prior and potential socio-demographic and psychosocial correlates of cycling, including safety concerns. Finally, we asked participants what could be done to make cycling safer and more attractive. We examined predictors of cycling using gender-stratified generalized linear models. Women interviewed along the street with a separate path reported cycling more than women on the other streets. A more favorable attitude towards cycling and greater habit strength were associated with more cycling in both men and women. Qualitative data revealed generally positive views about the bicycle boulevard, a need for education about sharing the road and for better cycling infrastructure in general. Our results suggest that, even in smaller cities, cycling infrastructure may encourage cycling, especially among women.

Download Full-text

Predicting Rates of Inbreeding in Populations Undergoing Selection

Genetics ◽

10.1093/genetics/154.4.1851 ◽

2000 ◽

Vol 154 (4) ◽

pp. 1851-1864 ◽

Cited By ~ 5

Author(s):

John A Woolliams ◽

Piter Bijma

Keyword(s):

Overlapping Generations ◽

Linear Models ◽

Selection Process ◽

Correction Term ◽

Random Mating ◽

Nonrandom Mating ◽

Selection Processes ◽

Genetic Contributions ◽

The Relationship

AbstractTractable forms of predicting rates of inbreeding (ΔF) in selected populations with general indices, nonrandom mating, and overlapping generations were developed, with the principal results assuming a period of equilibrium in the selection process. An existing theorem concerning the relationship between squared long-term genetic contributions and rates of inbreeding was extended to nonrandom mating and to overlapping generations. ΔF was shown to be ~¼(1 − ω) times the expected sum of squared lifetime contributions, where ω is the deviation from Hardy-Weinberg proportions. This relationship cannot be used for prediction since it is based upon observed quantities. Therefore, the relationship was further developed to express ΔF in terms of expected long-term contributions that are conditional on a set of selective advantages that relate the selection processes in two consecutive generations and are predictable quantities. With random mating, if selected family sizes are assumed to be independent Poisson variables then the expected long-term contribution could be substituted for the observed, providing ¼ (since ω = 0) was increased to ½. Established theory was used to provide a correction term to account for deviations from the Poisson assumptions. The equations were successfully applied, using simple linear models, to the problem of predicting ΔF with sib indices in discrete generations since previously published solutions had proved complex.

Download Full-text

Bayonet-shaped language development in autism with regression: a retrospective study

Molecular Autism ◽

10.1186/s13229-021-00444-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

David Gagnon ◽

Abderrahim Zeribi ◽

Élise Douard ◽

Valérie Courchesne ◽

Borja Rodríguez-Herreros ◽

...

Keyword(s):

Language Development ◽

Linear Models ◽

Autism Spectrum ◽

Early Language ◽

Verbal Iq ◽

Logistic Regression Models ◽

Language Level ◽

Language Outcome ◽

Almost All ◽

The Relationship

Abstract Background Language delay is one of the major referral criteria for an autism evaluation. Once an autism spectrum diagnosis is established, the language prognosis is among the main parental concerns. Early language regression (ELR) is observed by 10–50% of parents but its relevance to late language level and socio-communicative ability is uncertain. This study aimed to establish the predictive value of ELR on the progression of language development and socio-communicative outcomes to guide clinicians in addressing parents’ concerns at the time of diagnosis. Methods We used socio-communicative, language, and cognitive data of 2,047 autism spectrum participants from the Simons Simplex Collection, aged 4–18 years (mean = 9 years; SD = 3.6). Cox proportional hazard and logistic regression models were used to evaluate the effect of ELR on language milestones and the probability of using complex and flexible language, as defined by the choice of ADOS module at enrollment. Linear models were then used to evaluate the relationship of ELR and non-verbal IQ with socio-communicative and language levels. Results ELR is associated with earlier language milestones but delayed attainment of fluent, complex, and flexible language. However, this language outcome can be expected for almost all autistic children without intellectual disability at 18 years of age. It is mostly influenced by non-verbal IQ, not ELR. The language and socio-communicative level of participants with flexible language, as measured by the Vineland and ADOS socio-communicative subscales, was not affected by ELR. Limitations This study is based on a relatively coarse measure of ultimate language level and relies on retrospective reporting of early language milestones and ELR. It does not prospectively document the age at which language catches up, the relationship between ELR and other behavioral areas of regression, nor the effects of intervention. Conclusions For autistic individuals with ELR and a normal level of non-verbal intelligence, language development follows a “bayonet shape” trajectory: early first words followed by regression, a plateau with limited progress, and then language catch up.

Download Full-text

Gender Differences in Phytoestrogens and the Relationship with Speed of Processing in Older Adults: A Cross-Sectional Analysis of NHANES, 1999–2002

Nutrients ◽

10.3390/nu11081780 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1780 ◽

Cited By ~ 1

Author(s):

Alwerdt ◽

Patterson ◽

Sliwinski

Keyword(s):

Older Adults ◽

Gender Differences ◽

Cognitive Aging ◽

Linear Models ◽

Speed Of Processing ◽

Cross Sectional ◽

Health And Nutrition ◽

Performance Results ◽

Sectional Analysis ◽

The Relationship

Sex hormone changes in adults are known to play a part in aging, including cognitive aging. Dietary intake of phytoestrogens can mimic estrogenic effects on brain function. Since sex hormones differ between genders, it is important to examine gender differences in the phytoestrogen–cognition association. Therefore, the goal of this study is to examine the relationship between urinary phytoestrogens and speed of processing (SOP) and the variation of the association between genders in older adults. Participants were drawn from the 1999–2002 National Health and Nutrition Examination Survey and included 354 individuals aged 65–85 years old. General linear models (GLMs) were used to test for significant gender differences in the relationship between phytoestrogens and SOP. Results from the GLMs showed significant gender differences in the relationship between genistein and SOP. Higher levels of genistein were associated with better SOP in women. This relationship was reversed in men: higher genistein levels were associated with worse performance. Results indicate that there are distinct gender differences in the relationship between genistein and SOP. These results emphasize the importance of considering gender differences when devising dietary and pharmacologic interventions that target phytoestrogens to improve brain health.

Download Full-text

Diagnostic grammar and assessment: translating criteria into questions

Psychological Medicine ◽

10.1017/s0033291700011028 ◽

1989 ◽

Vol 19 (1) ◽

pp. 57-68 ◽

Cited By ~ 35

Author(s):

Lee N. Robins

Keyword(s):

Diagnostic Criteria ◽

Catchment Area ◽

Predictive Ability ◽

Diagnostic Interview ◽

Good Prediction ◽

Interview Schedule ◽

Validity Data ◽

Validity Assessment ◽

Standardized Interview ◽

The Relationship

SynopsisThere has been concern about whether standardized psychiatric interviews make valid diagnoses. Agreements between the Diagnostic Interview Schedule (DIS), as an example of a standardized interview, with independent assessments by a clinician are reasonably high in most studies, but the clinical assessment is itself of uncertain validity. Using predictive ability is an alternative way of judging validity. Data are presented to show that the DIS is almost as good at prediction as a clinician's assessment, but here too there are problems. Because prediction is probabilistic (i.e. the same disorder can have multiple outcomes, and different disorders can share outcomes), it is not possible to say how good prediction has to be to demonstrate perfect validity.Across varied methods of validity assessment, some disorders are regularly found more validly diagnosed than others, suggesting that part of the source of invalidity lies in the diagnostic grammar of the systems whose criteria standardized interviews evaluate. Sources of invalidity inherent in the content and structure of a variety of diagnoses in DSM-III and its heir, DSM-III-R, are reviewed and illustrated, in part with results from the Epidemiological Catchment Area study.The relationship between diagnostic criteria and standardized interviews is symbiotic. While attempts to adhere closely to existing diagnostic criteria contribute to the diagnostic accuracy of standardized interviews, the exercise of translating official diagnostic criteria into standardized questions highlights problems in the system's diagnostic grammar, enabling standardized interviews to contribute to improvements in diagnostic nosology.

Download Full-text