Estimating trembling aspen productivity in the boreal transition ecoregion of Saskatchewan using site and soil variables

Pinno, B. D. and Bélanger, N. 2011. Estimating trembling aspen productivity in the boreal transition ecoregion of Saskatchewan using site and soil variables. Can. J. Soil Sci. 91: 661–669. The productivity of trembling aspen, as expressed by site quality index (SQI), in natural stands growing on three different soil parent material types (fluvial, lacustrine and glacial till) in the boreal transition ecoregion of Saskatchewan was evaluated by using soil and site variables. The soil and site variables used were either general categorical variables, such as parent material and ecosite, or continuous variables, such as soil texture (percent sand or clay), pH, carbon, nitrogen, C:N ratios, and elemental composition. It was not possible to reliably estimate SQI using only categorical site variables or continuous soil variables when all plots were grouped together. However, when plots were grouped by parent material type, over 45% of the variability in trembling aspen productivity was explained using the common soil measurements of texture and pH. In estimating SQI, there was an interaction between both pH and soil texture with parent material. On fluvial and lacustrine parent materials, increased clay content was positively correlated with SQI, but was negatively correlated with SQI on till, while pH was positively correlated with SQI on fluvial parent material, but negatively on lacustrine. Including more sophisticated measures of soil nutrient availability in the forest floor and BC horizons did not improve the SQI prediction. This study indicates that it is possible to estimate trembling aspen productivity using simple site and soil variables, provided that differences in soil properties within parent material groupings are considered in the analysis.

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Prediction of soil nutrient regime based on a model of DEM-generated clay content for the province of Nova Scotia, Canada

Canadian Journal of Soil Science ◽

10.4141/cjss2012-016 ◽

2013 ◽

Vol 93 (2) ◽

pp. 193-203 ◽

Cited By ~ 3

Author(s):

Zhengyong Zhao ◽

M. Irfan Ashraf ◽

Kevin S. Keys ◽

Fan-Rui Meng

Keyword(s):

Nova Scotia ◽

High Resolution ◽

Soil Nutrient ◽

Clay Content ◽

Parent Material ◽

Forest Growth ◽

Soil Maps ◽

Large Area ◽

Nutrient Regime ◽

Coarse Resolution

Zhao, Z., Ashraf, M. I., Keys, K. S. and Meng, F-R. 2013. Prediction of soil nutrient regime based on a model of DEM-generated clay content for the province of Nova Scotia, Canada. Can. J. Soil Sci. 93: 193–203. Soil nutrient regime (SNR) maps are widely required by ecological studies as well as forest growth and yield assessment. Traditionally, SNR is assessed in the field using vegetation indicators, topography and soil properties. However, field assessments are expensive, time consuming and not suitable for producing high-resolution SNR maps over a large area. The objective of this research was to develop a new model for producing high-resolution SNR maps over a large area (in this case, the province of Nova Scotia). The model used 10-m resolution clay content maps generated from digital elevation model data to capture local SNR variability (associated with topography) along with coarse-resolution soil maps to capture regional SNR variability (associated with differences in landform/parent material types). Field data from 1385 forest plots were used to calibrate the model and another 125 independent plots were used for model validation. Results showed field-identified SNRs were positively correlated with predicted clay content, with some variability associated with different landform/parent material types. Accuracy assessment showed that 63.7% of model-predicted SNRs were the same as field assessment, with 96.5% within ±1 class compared with field-identified SNRs. The predicted high-resolution SNR map was also able to capture the influence of topography on SNR which was not possible when predicting SNR from coarse-resolution soil maps alone.

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Soil-Site Relations for Trembling Aspen in Northwest Ontario

Northern Journal of Applied Forestry ◽

10.1093/njaf/15.3.146 ◽

1998 ◽

Vol 15 (3) ◽

pp. 146-153 ◽

Cited By ~ 1

Author(s):

Willard H. Carmean ◽

Janjun Li

Keyword(s):

Clay Content ◽

Site Index ◽

Growth And Yield ◽

Site Quality ◽

Trembling Aspen ◽

Stem Analysis ◽

Drainage Class ◽

Soil Site ◽

Northwest Ontario ◽

Aspen Forest

Abstract Past harvesting in Northwest Ontario has produced increased regeneration and increased forest areas supporting trembling aspen stands, resulting in greatly increased utilization of aspen. Thus there is a critical need to accurately estimate site quality and growth and yield for trembling aspen and for identifying productive sites where more intensive aspen forest management can be practiced. Soil-site relations were studied using 95 plots located in mature, fully stocked, evenaged, undisturbed trembling aspen stands. On each plot site index (SIBH50) estimation was based on stem analysis of three to five dominant and codominant trees. Each plot also had soil profile descriptions and soil analyses for four major soil horizons (A, B, BC, C). Plots were located on morainal soils, glaciofluvial soils, and lacustrine soils. Multiple regression analyses showed: (a) for morainal soils site index was correlated (adj R² = 0.63) to depth to a root restricting layer, silt plus clay content of the A horizon, and coarse fragment content of the C horizon; (b) for glaciofluvial soils site index was correlated (adj R² = 0.64) to depth to a root restricting layer and to drainage class: and (c) for lacustrine soils site index was correlated (adj R² = 0.65) to depth to mottles and to clay content of the C horizon. Results are applicable only to medium and good sites where mature, fully stocked, merchantable trembling aspen stands commonly occur. North. J. Appl. For. 15(3):146-153.

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Relationship between color value and nitrogen in forest mineral soils

Canadian Journal of Soil Science ◽

10.4141/cjss93-006 ◽

1993 ◽

Vol 73 (1) ◽

pp. 61-72 ◽

Cited By ~ 5

Author(s):

H. Qian ◽

K. Klinka ◽

L. M. Lavkulich

Keyword(s):

Soil Moisture ◽

Soil Texture ◽

Mineral Soil ◽

Estimation Procedure ◽

Categorical Variables ◽

Soil Color ◽

Total N ◽

Soil Variables ◽

Color Value ◽

Mineral Soils

To assess the extent to which moist color value of forest mineral soils supports their differentiation according to concentrations of mineralizable and total N, 239 samples of 0–30-cm mineral-soil layers were examined for the relationship between nitrogen measures and selected categorical climatic and soil variables. The best regression models, using soil color value (SCV), climate, soil moisture and soil texture as categorical variables, explained nearly 70% of the variation in both mineralizable and total N, with climate accounting for most of the variation. The results provided support for the present usage of SCV in estimating mineralizable and total N in forest soils but suggested improvements for the development of a more effective estimation procedure. Key words: Forest soil color, soil nitrogen, climate, soil moisture, soil texture, regression analysis

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Preoperative MRI findings and prediction of diagnostic utility of foramen ovale electrodes

Journal of Neurosurgery ◽

10.3171/2018.12.jns182093 ◽

2020 ◽

Vol 132 (3) ◽

pp. 692-699 ◽

Cited By ~ 1

Author(s):

Sarah K. Bick ◽

Marjan S. Dolatshahi ◽

Benjamin L. Grannan ◽

Andrew J. Cole ◽

Daniel B. Hoch ◽

...

Keyword(s):

Minimally Invasive ◽

Treatment Decision ◽

Temporal Lobectomy ◽

Categorical Variables ◽

Continuous Variables ◽

Foramen Ovale ◽

Mri Findings ◽

Noninvasive Methods ◽

Diagnostic Modality ◽

Diagnostic Investigations

OBJECTIVEForamen ovale electrodes (FOEs) are a minimally invasive method to localize mesial temporal seizures in cases in which noninvasive methods are inconclusive. The objective of this study was to identify factors predicting the ability of FOEs to yield a diagnosis in order to determine optimal candidates for this procedure.METHODSAll cases of diagnostic investigations performed with FOEs at the authors’ institution between 2005 and 2017 were reviewed. FOE investigation was defined as diagnostic if it led to a treatment decision. Demographic and clinical variables for diagnostic and nondiagnostic investigations were compared using a Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables.RESULTSNinety-three patients underwent investigations performed with FOEs during the study period and were included in the study. FOE investigation was diagnostic in 75.3% of cases. Of patients who underwent anterior temporal lobectomy following diagnostic FOE evaluation, 75.9% were Engel class I at last follow-up (average 40.1 months). When the diagnostic and nondiagnostic FOE groups were compared, patients who had diagnostic investigations were more likely to be male (57.1% male vs 26.1% in the nondiagnostic group, p = 0.015). They were also more likely to have temporal lesions on preoperative MRI (p = 0.018).CONCLUSIONSFOEs are a useful, minimally invasive diagnostic modality resulting in a treatment decision in 75% of cases. Male patients and patients with temporal lesions on MRI may be most likely to benefit from FOE investigation.

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Small Choroidal Melanoma: Correlation of Growth Rate with Pathology

Ocular Oncology and Pathology ◽

10.1159/000517203 ◽

2021 ◽

pp. 1-10

Author(s):

Vishal Raval ◽

Shiming Luo ◽

Emily C. Zabor ◽

Arun D. Singh

Keyword(s):

Growth Rate ◽

Retinal Pigment ◽

Choroidal Melanoma ◽

Case Series ◽

Subretinal Fluid ◽

Categorical Variables ◽

Continuous Variables ◽

Basal Diameter ◽

Orange Pigment ◽

Rpe Atrophy

Purpose: The aim of the study was to evaluate equivalence of growth rate and pathologic confirmation in small choroidal melanoma (SCM). Design: This study is a case series. Subjects, Participants, and Controls: A total of 61 patients with a choroidal melanocytic tumor of size 5.0–16.0 mm in the largest basal diameter and 1.0–2.5 mm in thickness were classified into the pathology-confirmed group (n = 19), growth-confirmed group (n = 30), and with combined observations (n = 12). Methods: Distribution of clinical variables (age, gender, laterality, tumor dimensions, tumor location, and presence of orange pigment, subretinal fluid, drusen, and retinal pigment epithelial [RPE] atrophy) between the groups was analyzed. Patient and disease characteristics were summarized as the median and interquartile range for continuous variables and the frequency and percentage for categorical variables. Comparisons were made using the Wilcoxon rank sum test for continuous variables and either Fisher’s exact test or the χ2 test for categorical variables with a p value threshold of 0.05 for statistical significance. Growth rate (change in basal dimension/12 months) diagnostic of SCM was quantified. Main Outcome Measures: The primary aim of this study was to test the hypothesis that “growth” was diagnostic of SCM with the secondary aim of quantifying the malignant “growth rate” (growth rate of SCM). Results: The clinical characteristics among all 3 groups were similar except more patients with symptoms (68 vs. 20 vs. 42%, p = 0.004) and juxtapapillary location (p = 0.03) were in the pathology group than in the growth-confirmed group. Those in the combined and growth-confirmed groups had more patients with drusen (11 vs. 60 vs. 50%, p = 0.003) and RPE atrophy (11 vs. 23 vs. 67%, p = 0.003), respectively, than in the pathology group. The median time to detect growth was 9 months (range 3–26 months). The mean growth rate in basal dimension was 1.8 mm/12 months (range, 0.0–7.4 mm; [95% CI: 1.32–2.28]). Conclusions and Relevance: Choroidal melanocytic lesions exhibiting a defined growth rate can be clinically diagnosed as SCM without a need for biopsy.

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A22 PREVALENCE OF IRON DEFICIENCY AND SUPPLEMENTATION PRACTICES FOR PATIENTS ON HOME PARENTERAL NUTRITION

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwab002.021 ◽

2021 ◽

Vol 4 (Supplement_1) ◽

pp. 289-291

Author(s):

L Russell ◽

R Mangat ◽

J Plant ◽

S Hansen ◽

D Armstrong ◽

...

Keyword(s):

Iron Deficiency ◽

Parenteral Nutrition ◽

Serum Iron ◽

Iron Supplementation ◽

Deficiency Anemia ◽

Categorical Variables ◽

Continuous Variables ◽

Prescribing Practices ◽

Sex Diagnosis ◽

Funding Agencies

Abstract Background Iron deficiency (ID) is common in patients receiving parenteral nutrition (PN), likely due to a lack of iron in the PN formula. There is no clear consensus on how often serum iron should be tested or iron supplementation should be given, at which dose or route, in patients on long-term PN. Within the Hamilton Health Sciences (HHS) home PN (HPN) program, the prevalence of ID or iron deficiency anemia (IDA) is unknown. This knowledge will contribute to better iron prescribing practices with ultimate benefit on patient’s health. Aims To assess the prevalence of ID and IDA in patients enrolled in the HHS HPN Program. The secondary aim was to assess supplementation practices for patients enrolled in the HPN program according to gastrointestinal(GI) diagnosis and duration on PN. Methods We conducted a retrospective study including consecutive adult patients enrolled in the HHS-HPN program from January 2015 to November 2020. We collected data on demographics (age, sex, and GI diagnosis), iron supplementation (dose, duration, and route), and information related to iron-deficiency (hemoglobin, serum iron, ferritin, TIBC, and folate) at pre-set intervals (enrollment, 3, 6, 12, 18, 24, 30, 36, 48, 60 months) and last measured. ID was defined as ferritin ≤45μg/L or serum iron ≤9μmol/L. IDA was defined as hemoglobin <130g/L in men or <120g/L in women in the context of ID. Data were expressed as median (IQR) for continuous variables and n/N(%) for categorical variables. Chi2 was performed to assess differences between groups and logistic regression to assess predictors of ID and IDA. The analysis was conducted using SPSS software(v26). Results The analysis included 125 HPN patients (50 males, median age of 55 (40–65) years). Patients received PN for a median of 195 (83–521) days. The most common diagnoses were malignancy (36.8%) and inflammatory bowel disease (23.2%); the most common indications for HPN was short bowel (29.6%) and bowel obstruction (27.2%). Iron profiles were measured in 77% of patients. At enrollment, 42.2% of patients had ID and 38.9% had IDA. Only 13% of patients with ID and 22.8% with IDA had iron supplementation (Figure 1). A total of 38 patients received iron either oral or IV (oral=44.7% vs IV=55.3%; p=0.66). There was no correlation between low levels of serum iron or ferritin with iron supplementation (p=0.23, 0.45 respectively). Age, sex, diagnosis, or reason for PN did not correlate with ID or IDA at any time point. Conclusions Iron-deficiency and IDA are common in patients enrolled in the HHS HPN program independently of age, sex, diagnosis and reason for PN. Prospective studies are needed to implement the most effective way to ensure proper monitoring and treatment of iron deficiency in this population. Funding Agencies None

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1341. Blood Volume Collected for Blood Cultures in Infants with Suspected Neonatal Sepsis in the NICU

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1523 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S682-S682

Author(s):

Maria S Rueda Altez ◽

Lamia Soghier ◽

Joseph M Campos ◽

James Bost ◽

Jiaxiang Gai ◽

...

Keyword(s):

Bloodstream Infection ◽

Blood Volume ◽

Bloodstream Infections ◽

Blood Cultures ◽

Categorical Variables ◽

Continuous Variables ◽

Volume Calculation ◽

Culture Negative ◽

Time Of Collection ◽

Rule Out

Abstract Background Blood cultures have high sensitivity to detect bacteremia in septic neonates when >=1 ml of blood is collected. Neonatologists often cite low confidence in microbiologic sampling as rationale for continuing antibiotics without a focus of infection despite negative blood cultures, resulting in prolonged antimicrobial therapy. We aim to describe the blood culture sample volumes in NICU patients, to identify factors associated with sample volumes < 1ml, and to compare the sample volumes of patients treated for culture-negative sepsis with those with bloodstream infections and those treated for a ≤72-hour sepsis rule-out Methods Data from this observational cohort study were collected retrospectively and prospectively from NICU patients with blood cultures obtained from September 2018 to February 2019. Clinical data were collected through chart review. All inoculated culture bottles were weighed for volume calculation. We determined the association of age, weight, sample source, and time of collection with volume < 1mL. Continuous variables were analyzed using Wilcoxon-Mann-Whitney, and categorical variables using chi-squared test. For aim 3, the volumes of the groups were compared using analysis of variance. Results A total of 310 blood cultures were identified, corresponding to 159 patients. Of these, 49 (16%) were positive. Among the negative blood cultures, 86% were collected in patients who subsequently received antibiotics (Figure 1). Median inoculated volume was 0.6 ml (IQR: 0.1-2.4). Weight and age at time of culture collection, source of sample, and time of collection were not significantly associated with the inoculation of < 1ml of blood. Median volume of blood was 0.6ml (0.3-0.6) for sepsis rule-out, 0.6ml (0.2-0.6) for bloodstream infection, and 0.6ml (0.6-1.4) for culture-negative sepsis. No difference was found among the three groups (p=0.54) Figure 1. Classification of blood cultures identified during study period Conclusion The blood volume collected for cultures in the NICU is lower than recommended. Clinical and environmental characteristics are not significantly associated with the inoculated volume. The volume of blood sampled does not differ in patients with culture-negative sepsis, bloodstream infection and sepsis rule-out, and should not be a justification for longer duration of antibiotic therapy Disclosures All Authors: No reported disclosures

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Epilepsy as a Comorbidity in Polymyositis and Dermatomyositis—A Cross-Sectional Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18083983 ◽

2021 ◽

Vol 18 (8) ◽

pp. 3983

Author(s):

Ella Nissan ◽

Abdulla Watad ◽

Arnon D. Cohen ◽

Kassem Sharif ◽

Johnatan Nissan ◽

...

Keyword(s):

Proportional Hazards ◽

Cross Sectional Study ◽

Cox Proportional Hazards ◽

Categorical Variables ◽

Rank Test ◽

Control Group ◽

Multivariable Logistic Regression Analysis ◽

Positive Trend ◽

Continuous Variables ◽

Cross Sectional

Polymyositis (PM) and dermatomyositis (DM) are autoimmune-mediated multisystemic myopathies, characterized mainly by proximal muscle weakness. A connection between epilepsy and PM/DM has not been reported previously. Our study aim is to evaluate this association. A case–control study was conducted, enrolling a total of 12,278 patients with 2085 cases (17.0%) and 10,193 subjects in the control group (83.0%). Student’s t-test was used to evaluate continuous variables, while the chi-square test was applied for the distribution of categorical variables. Log-rank test, Kaplan–Meier curves and multivariate Cox proportional hazards method were performed for the analysis regarding survival. Of the studied 2085 cases, 1475 subjects (70.7%) were diagnosed with DM, and 610 patients (29.3%) with PM. Participants enrolled as cases had a significantly higher rate of epilepsy (n = 48 [2.3%]) as compared to controls (n = 141 [1.4%], p < 0.0005). Using multivariable logistic regression analysis, PM was found only to be significantly associated with epilepsy (OR 2.2 [95%CI 1.36 to 3.55], p = 0.0014), whereas a non-significant positive trend was noted in DM (OR 1.51 [95%CI 0.99 to 2.30], p = 0.0547). Our data suggest that PM is associated with a higher rate of epilepsy compared to controls. Physicians should be aware of this comorbidity in patients with immune-mediated myopathies.

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Association between Short Hours of Sleep and Overweight/Obesity in Mexican Adolescent Population: A School-Based Cross-Sectional Study

Healthcare ◽

10.3390/healthcare9080939 ◽

2021 ◽

Vol 9 (8) ◽

pp. 939

Author(s):

Ana Fresan ◽

Alma Delia Genis-Mendoza ◽

María Lilia López-Narváez ◽

Tania Guadalupe Gómez-Peralta ◽

Daniela Georgina Aguilar-Velázquez ◽

...

Keyword(s):

Cross Sectional Study ◽

The Body ◽

Categorical Variables ◽

Continuous Variables ◽

Sectional Study ◽

Cross Sectional ◽

Obese Adolescent ◽

School Based ◽

Prevalence Of Obesity ◽

Mexican Adolescents

Background/Aim: Obesity in adolescents is increasing; as such, the aim of this study was to determine the prevalence of obesity in Mexican adolescents and examine its possible association with hours of sleep. Methods: A school-based cross-sectional study was carried out. This study included 863 adolescents aged between 11 and 16 years. The prevalence of obesity was estimated using the body mass index (BMI). The duration of sleep (and other information) was assessed by a self-reported questionnaire. The Cochran–Mantel–Hansel test for categorical variables and a general linear model for continuous variables were used to evaluate the interaction effect of BMI and sex with respect to sleeping and assessed activity conditions. Results: It was found that 47.6% of the adolescents were overweight/obese. Men were more frequently overweight/obese than women (52.6% vs. 41.8%, p = 0.002). Moreover, overweight/obese adolescents were younger and spent fewer daily hours watching television (p < 0.05). Men practiced sports more hours per week than women (p = 0.04). However, women spent more daily time on the internet (p = 0.05), and overweight/obese adolescent women slept fewer hours than overweight/obese men and adolescents with normal weight (p = 0.008). Conclusions: The development of strategies for the prevention of overweight/obesity and the improvement of sleep duration should include a gender perspective to improve health habits in Mexican adolescents.

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Relationship of Hydroxychloroquine and Ophthalmic Complications in Patients with Type 2 Diabetes in Taiwan

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18158154 ◽

2021 ◽

Vol 18 (15) ◽

pp. 8154

Author(s):

Hung-Chih Chen ◽

Hung-Yu Lin ◽

Michael Chia-Yen Chou ◽

Yu-Hsun Wang ◽

Pui-Ying Leong ◽

...

Keyword(s):

Type 2 Diabetes ◽

Conditional Logistic Regression ◽

Categorical Variables ◽

Control Group ◽

Case Group ◽

Research Database ◽

Continuous Variables ◽

Chi Square ◽

Increased Risk

The purpose of this study is to evaluate the relationship between hydroxychloroquine (HCQ) and diabetic retinopathy (DR) via the national health insurance research database (NHIRD) of Taiwan. All patients with newly diagnosed type 2 diabetes (n = 47,353) in the NHIRD (2000–2012) were enrolled in the study. The case group consists of participants with diabetic ophthalmic complications; 1:1 matching by age (±1 year old), sex, and diagnosis year of diabetes was used to provide an index date for the control group that corresponded to the case group (n = 5550). Chi-square test for categorical variables and Student’s t-test for continuous variables were used. Conditional logistic regression was performed to estimate the adjusted odds ratio (aOR) of DR. The total number of HCQ user was 99 patients (1.8%) in the case group and 93 patients (1.7%) in the control group. Patients with hypertension (aOR = 1.21, 95% CI = 1.11–1.31) and hyperlipidemia (aOR = 1.65, 95% CI = 1.52–1.79) significantly increased the risk of diabetic ophthalmic complications (p < 0.001). Conversely, the use of HCQ and the presence of rheumatoid diseases did not show any significance in increased risk of DR. HCQ prescription can improve systemic glycemic profile, but it does not decrease the risk of diabetic ophthalmic complications.

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