Species Distribution Modeling of American Beech (Fagus Grandifolia) Distribution in Southwest Ohio

2017 ◽  
Vol 8 (3) ◽  
pp. 16-36 ◽  
Author(s):  
Brandon Flessner ◽  
Mary C. Henry ◽  
Jerry Green
Keyword(s):  
Linear Model ◽  
Species Distribution ◽  
Small Sample Size ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Small Sample ◽  
Environmental Data ◽  
Continuous Variables ◽  
American Beech ◽  
Boosted Regression Tree

The ability to predict American beech distribution (Fagus grandifolia Ehrh.) from environmental data was tested by using a geographic information system (GIS) in tandem with species distribution models (SDMs). The study was conducted in Butler and Preble counties in Ohio, USA. Topography, soils, and disturbance were approximated through 15 predictor variables with presence/absence and basal area serving as the response variables. Using a generalized linear model (GLM) and a boosted regression tree (BRT) model, curvature, elevation, and tasseled cap greenness were shown to be significant predictors of beech presence. Each of these variables was positively related to beech presence. A linear model using presence only data was not effective in predicting basal area due to a small sample size. This study demonstrates that SDMs can be used successfully to advance one's understanding of the relationship between tree species presence and environmental factors. Large sample sizes are needed to successfully model continuous variables.

Species Distribution Modeling of American Beech (Fagus Grandifolia) Distribution in Southwest Ohio

2019 ◽  
pp. 1298-1320
Author(s):  
Brandon Flessner ◽  
Mary C. Henry ◽  
Jerry Green
Keyword(s):  
Linear Model ◽  
Species Distribution ◽  
Small Sample Size ◽  
Regression Tree ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Environmental Data ◽  
Continuous Variables ◽  
Distribution Models ◽  
American Beech

The ability to predict American beech distribution (Fagus grandifolia Ehrh.) from environmental data was tested by using a geographic information system (GIS) in tandem with species distribution models (SDMs). The study was conducted in Butler and Preble counties in Ohio, USA. Topography, soils, and disturbance were approximated through 15 predictor variables with presence/absence and basal area serving as the response variables. Using a generalized linear model (GLM) and a boosted regression tree (BRT) model, curvature, elevation, and tasseled cap greenness were shown to be significant predictors of beech presence. Each of these variables was positively related to beech presence. A linear model using presence only data was not effective in predicting basal area due to a small sample size. This study demonstrates that SDMs can be used successfully to advance one's understanding of the relationship between tree species presence and environmental factors. Large sample sizes are needed to successfully model continuous variables.

Abstract W P224: Higher Pre-Hospital Blood Pressure Prolongs Door to Needle Thrombolysis Times

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Digvijaya Navalkele ◽  
Chunyan Cai ◽  
Mohammad Rahbar ◽  
Renganayaki Pandurengan ◽  
Tzu-Ching Wu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Small Sample Size ◽  
Heart Association ◽  
Small Sample ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Intravenous Tissue Plasminogen Activator ◽  
Number Of Patients

Background: Per American Heart Association guidelines, blood pressure (BP) should be < 185/110 to be eligible for intravenous tissue plasminogen activator (tPA). It is shown that door to needle (DTN) time is prolonged in patients who require anti-hypertensive medications prior to thrombolysis in the emergency department (ED). To our knowledge, no studies have focused on pre-hospital BP and its impact on DTN times. We hypothesize that DTN times are longer for patients with higher pre-hospital BP. Methods: We conducted a retrospective review of acute ischemic stroke patients who presented between 1/2010 and 12/2010 to our ED through Emergency Medical Services (EMS) within 3-hrs of symptom onset. Patients were identified from our registry and categorized into two groups: Pre-hospital BP ≥ 185/110 (Pre-hsp HBP) and < 185/110 (Pre-hsp LBP). BP records were abstracted from EMS sheets. Two groups were compared using two-sample t-test or Wilcoxon rank sum test for continuous variables and Chi-square test or Fisher’s exact test for categorical variables. Results: A total of 107 consecutive patients were identified. Out of these, 75 patients (70%) were treated with tPA. Among the patients who received thrombolysis, 35% had pre-hospital BP ≥ 185/110 (n= 26/75). Greater number of patients required anti-hypertensive medications in ED in high BP group compared to low BP group (Pre-hsp HBP n= 14/26, 54%; Pre-hsp LBP n= 13/49, 27%, p < 0.02). Mean door to needle times were significantly higher in Pre-hsp HBP group. (mean ± SD 87.5± 34.2 Vs. 59.7±18.3, p<0.0001). Analysis of patients only within the Pre-hsp HBP group (n= 26) revealed that DTN times were shorter if patients received pre-hsp BP medications compared to patients in the same group who did not receive pre-hsp BP medication (n= 10 vs 16; mean ± SD 76.5 ± 25.7 Vs. 94.3 ± 37.7, p = 0.20) Conclusion: Higher pre-hospital BP is associated with prolonged DTN times and it stays prolonged if pre-hospital high BP remains untreated. Although the later finding was not statistical significant due to small sample size, pre-hospital blood pressure control could be a potential area for improvement to reduce door to needle times in acute ischemic stroke.

Present-day expansion of American beech in northeastern hardwood forests: Does soil base status matter?

2009 ◽  
Vol 39 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Basal Area ◽  
Base Cation ◽  
Hardwood Forests ◽  
Fagus Grandifolia ◽  
Soil Base ◽  
Large Area ◽  
American Beech ◽  
Permanent Sample Plots

Recently, sugar maple ( Acer saccharum Marsh.) decline in northeastern North America has been regarded as a major factor structuring hardwood forests by favouring American beech ( Fagus grandifolia Ehrh.) in the understory of maple-dominated stands. To determine whether soil fertility differences associated with sugar maple decline may have promoted the expansion of American beech, we explored the relationships between the soil base status and the sapling and tree strata density and composition, using data from 426 permanent sample plots distributed throughout Quebec. Our results indicate that American beech is currently expanding in the sugar maple range of Quebec. The abundance and proportion of American beech in the sapling stratum are mainly associated with the proportion of American beech in the tree stratum, the relative basal area of dead sugar maple trees, and the base status of soils. In accordance with the many studies reporting on the high sensitivity of sugar maple to the acid–base status of soils and the decline of the sugar maple population, this study supports the hypothesis that soil base cation depletion, caused in part by atmospheric acid deposition, is among the main factors involved in the present-day expansion of American beech over a large area in Quebec.

scholarly journals New findings on protected and strictly protected species confirm the value of the prime hoverfly area network

2018 ◽  
pp. 63-71
Author(s):  
Marina Jankovic ◽  
Marija Milicic ◽  
Dimitrije Radisic ◽  
Dubravka Milic ◽  
Ante Vujic
Keyword(s):  
Protected Areas ◽  
Species Distribution ◽  
Species Distribution Models ◽  
Small Sample Size ◽  
Small Sample ◽  
Area Network ◽  
Distribution Models ◽  
Environmental Pressures ◽  
New Findings ◽  
Using Data

With environmental pressures on the rise, the establishment of pro?tected areas is a key strategy for preserving biodiversity. The fact that many species are losing their battle against extinction despite being within protected areas raises the question of their effectiveness. The aim of this study was to evaluate established Priority Hoverfly Areas (PHAs) and areas that are not yet but could potentially be included in the PHA network, using data from new field surveys. Additionally, species distribution models have been created for two new species recognized as important and added to the list of key hoverfly species. Maps of potential distribution of these species were superimposed on maps of protected areas and PHAs to quantify percentages of overlap. The results of this study are not statisti?cally significant, which could be influenced by a small sample size. However, the results of species distribution models and the extent of overlap with PHAs confirm the utility of these expert-generated designations.

Methylated DNA markers for monitoring palliative chemotherapy response in advanced colorectal cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15511-e15511
Author(s):  
Mojun Zhu ◽  
Douglas W. Mahoney ◽  
Kelli Burger ◽  
Patrick H. Foote ◽  
Karen A. Doering ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Treatment Response ◽  
Systemic Therapy ◽  
Small Sample Size ◽  
High Sensitivity ◽  
Response Assessment ◽  
Small Sample ◽  
Chemotherapy Response ◽  
Continuous Variables ◽  
Methylated Dna

e15511 Background: Aberrantly methylated DNA marker (MDM) candidates are strongly associated with primary colorectal cancer (CRC) before treatment and detect CRC recurrence with high sensitivity when assayed from plasma. The relationship of these MDMs in association to chemotherapy treatment response is unknown. Methods: In a prospective cohort of patients receiving systemic therapy for advanced CRC, peripheral blood was collected serially during restaging visits. 15 patients were retrospectively identified to have partial response (PR), stable disease (SD) and progressive disease (PD) to treatment (n=5 for each group) based on the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Using paired samples from each patient before and after response assessment, we analyzed 11 MDMs ( GRIN2D, ZNF671, ANKRD13B, QKI, VAV3, JAM3, SFMBT2, CHST2, ZNF568, FER1L4 and CNNM1) to assess correlation with treatment response. Cell-free DNA was extracted and bisulfite treated before MDMs were quantified by target enrichment long-probe quantitative-amplified signal assay and normalized to a methylated sequence of B3GALT6. Continuous variables are summarized as a median with corresponding interquartile ranges (IQR) and comparisons between subgroups were based on the Wilcox Rank Sums test. Results: The median interval between pre- and post-response assessment visits was 69 days (IQR: 63-83 days) and the level of tumor burden at pre-assessment was similar across all response types (Table 1). Patients with PD had higher levels of methylated GRIN2D, ZNF671 and ANKRD13B than those with PR or SD at baseline and may offer additional prognostic value over CEA which was similar in the PR and PD groups before treatment (Table 1). Elevation of pre-assessment MDMs preceded radiographic evidence of disease progression by 82 days (IQR 69-83 days). Conclusions: Three MDMs, GRIN2D, ZNF671 and ANKRD13B, were found to reflect treatment response (PD vs. PR + SD) as shown in the table. Although this pilot study was limited by a small sample size, it demonstrated the feasibility of using plasma-based MDMs in monitoring treatment response to systemic therapy for advanced CRC and should be compared to CEA in a larger study.[Table: see text]

Early progression (progr) in patients (pts) with metastatic pancreatic cancer (mPaC) and a germline BRCA mutation (gBRCAm): Phase III POLO trial of olaparib (O) versus placebo (P).

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 750-750
Author(s):  
Teresa Macarulla ◽  
Hedy L. Kindler ◽  
Pascal Hammel ◽  
Michele Reni ◽  
Eric Van Cutsem ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Brca Mutation ◽  
Standard Of Care ◽  
Complete Response ◽  
Small Sample ◽  
Phase Iii ◽  
Stepwise Logistic Regression ◽  
Continuous Variables ◽  
Platinum Based Chemotherapy ◽  
Stepwise Logistic Regression Model

750 Background: In POLO (NCT02184195), maintenance O was associated with significant progr-free survival benefit vs P in pts with a gBRCAm and mPaC (Golan NEJM 2019). Early progr or death (within 4 months [m]) occurs in ~35−45% of pts on standard-of-care first-line (1L) chemotherapy for mPaC (Conroy NEJM 2011; von Hoff NEJM 2013); however, predictive factors are currently unknown and early progr has not been addressed in the maintenance setting. We examined factors potentially associated with early progr in POLO. Methods: Following ≥16 weeks of 1L platinum-based chemotherapy (PBC) without progr, pts were randomized to maintenance O (tablets; 300 mg bd) or P until progr or unacceptable toxicity. Early progr was defined as progr (by blinded independent central review) or death within 4 m of randomization. A stepwise logistic regression model included baseline (BL) factors age, albumin, lactate dehydrogenase (LDH), global health status (GHS) and physical functioning (PhysF) as continuous variables, and discrete variables listed in the Table. Results: 62/154 randomized pts (40%) were defined as early progressors (EP; Table). Due to missing BL data, the multivariate analysis included 127 pts (56 EPs [44%]). Lower BL PhysF score (continuous) was significantly associated with early progr ( P= 0.02); no difference for partial/complete response (PR/CR) vs stable disease (SD). Conclusions: While small sample size limited analysis power, PhysF score was the only BL factor significantly associated with early progr in pts with a gBRCAm and mPaC in the POLO trial of maintenance O vs P. Clinical trial information: NCT02184195 . [Table: see text]

Beyond oak regeneration: modelling mesophytic sapling density drivers along topographic, edaphic, and stand-structural gradients in mature oak-dominated forests of Appalachian Ohio

2020 ◽  
Vol 50 (11) ◽  
pp. 1215-1227
Author(s):  
Don C. Radcliffe ◽  
Stephen N. Matthews ◽  
David M. Hix
Keyword(s):  
Sugar Maple ◽  
Acer Rubrum ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Active Management ◽  
Permanent Plots ◽  
Eastern United States ◽  
Red Maple ◽  
American Beech ◽  
Sapling Density

Shade-tolerant mesophytic tree species tend to dominate the understories of present-day oak–hickory and mixed-hardwood forests in the eastern United States. We quantified the sapling density associations with abiotic and biotic variables for three important mesophytic species: red maple (Acer rubrum L.), sugar maple (Acer saccharum Marsh.), and American beech (Fagus grandifolia Ehrh.) in southeastern Ohio. In this study, we sampled 165 permanent plots in oak-dominated, topographically diverse, mature (>90 years old), second-growth forests following a time span of 21–25 years (1993–1995 and 2016–2018) between samples on the Athens and Marietta units of the Wayne National Forest. Our models showed that sugar maple was strongly associated with high pH soils and red maple was strongly associated with low pH soils. Additionally, red maple was associated with upper slope positions and older stands, while American beech was associated with lower slopes, northeasterly aspects, and northeast-facing upper slopes. Basal area of competing species, solum depth, and management unit were not significantly related to sapling density for our focal species. American beech sapling density doubled between the two sampling periods, while densities of both maple species declined by half. Our results will help scientists and managers by providing insight into potential future composition of currently oak-dominated forests in areas without active management intervention.

scholarly journals Preharvest Manual Herbicide Treatments for Controlling American Beech in Central West Virginia

2004 ◽  
Vol 21 (1) ◽  
pp. 40-49 ◽  
Author(s):  
Jeffrey D. Kochenderfer ◽  
James N. Kochenderfer ◽  
David A. Warner ◽  
Gary W. Miller
Keyword(s):  
West Virginia ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Black Cherry ◽  
American Beech ◽  
Complete Control ◽  
Area Reduction ◽  
Herbicide Treatments ◽  
Application Methods ◽  
Four Levels

Abstract Application costs and efficacy were determined for manual preharvest herbicide treatments applied to control American beech (Fagus grandifolia Ehrh.) that was interfering with the establishment and development of black cherry (Prunus serotina Ehrh.) in central West Virginia. The treatments consisted of four levels of basal area reduction using combinations of two application methods: hack-and-squirt injection with Accord (41.5%) and basal spraying with Garlon 4 (61.6% butoxyethyl ester). The treatments were applied in late Aug. 2000 and evaluated 12 months after treatment. A numerical rating system ranging from 1 to 7 (0–100% crown affected), based on a visual estimation of top kill, was used to evaluate the efficacy of each treatment. Trees receiving a rating of 5 (75% crown control) or greater were considered controlled. After 12 months, almost complete control (99%) was achieved with both application methods. Injection of ≥6.0-in. dbh beech stems also controlled 52% and 21.6% of small untreated beech understory stems in the 2-ft tall to 0.9-in. dbh and 1.0- to 5.9-in. dbh classes, respectively. Average application costs (chemical and labor) ranged from $39.28/ac for injection of 159 stems/ac ≥6 in. dbh to $80.32/ac for basal spraying 396 stems/ac in the 1.0- to 5.9-in. dbh class and $230.09/ac for basal spraying 3,743 stems/ac in the 2-ft tall to 0.9-in. dbh class. Basal spraying the numerous small 2-ft tall to 0.9-in. dbh stems dramatically increased treatment costs. Black cherry occupied 30% of total stand basal area and accounted for 91% of total stand value ($6,288.10/ac). Application costs expressed as a percentage of total stand value ranged from <1% for the injection-only treatment up to 6.5% for combination basal spray and injection treatments. The individual stem herbicide application methods described here are applicable to the steep topography and small nonindustrial ownerships found in Appalachia.

Assessment of time from cytoreductive nephrectomy (CN) to initiation of targeted therapy (TT) in patients with metastatic renal cell carcinoma (mRCC).

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 540-540
Author(s):  
Winston Vuong ◽  
Mark Chang ◽  
Nora Ruel ◽  
Joann Hsu ◽  
Courtney Carmichael ◽  
...  
Keyword(s):  
De Novo ◽  
Small Sample Size ◽  
Demographic Data ◽  
Small Sample ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Cytoreductive Nephrectomy ◽  
Impaired Wound Healing ◽  
Estimated Blood Loss ◽  
Surgical Data

540 Background: For patients (pts) with de novo mRCC, the initiation of TT typically occurs at a window of 4-6 weeks following CN. Although this practice is thought to mitigate impaired wound healing, bleeding and other complications (cx) in the perioperative period potentially related to antiangiogenic TT, there is limited data to support this practice. Methods: An institutional database including over 670 pts with RCC was interrogated. Pts with de novo mRCC who had received CN and subsequent TT were identified. When available, demographic data, Charlson comorbidity index (CCI), body mass-index (BMI) and surgical data (estimated blood loss [EBL], intraoperative cx, etc.) were recorded. ICD-9 codes recorded up to 90 days following CN were evaluated; newly applied diagnoses with possible relationship to surgery were considered to be potential postoperative cx. For continuous variables, the Spearman correlation test was used to determine associations with time to TT. For categorical variables, Kaplan-Meier analyses were conducted to determine if time to TT varied across subgroups. Results: Of 270 pts with mRCC, 79 pts received cytoreductive nephrectomy. Of these, 36 pts received TT as an initial treatment strategy (others received IL-2, IFN or chemotherapy), and 30 pts had a documented date of TT initiation. Two pts were removed given receipt of preoperative TT, resulting in a total of 28 pts in the current analysis. Median time to TT was 46 days (range, 28-93). Median overall survival for the overall cohort was 17.2 months. No association was found between age, BMI, CCI, number of sites of metastasis and time to TT. Time to TT did not vary by race (Caucasian v other) or class of TT (VEGF-directed therapy v mTOR inhibitor). Furthermore, EBL and the frequency of intraoperative cx did not vary by time to TT. The most frequently encountered postoperative cx included pleural effusion, pain, fatigue and nausea. Conclusions: With the caveat of our small sample size, the lack of an association between operative cx and time to TT suggests that an abbreviated timeframe between CN and TT may be entertained. These findings warrant exploration in larger series and/or prospective validation.

scholarly journals 225. Risk Factors for Mortality in Stenotrophomonas Bacteremia: A Retrospective Study

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S220-S220
Author(s):  
Glen Huang ◽  
Matthew R Davis ◽  
Paul R Allyn
Keyword(s):  
Los Angeles ◽  
Small Sample Size ◽  
Small Sample ◽  
Categorical Variables ◽  
Common Source ◽  
High Dose ◽  
Continuous Variables ◽  
Hospital System ◽  
Optimal Therapy ◽  
The Impact

Abstract Background Stenotrophomonas is a gram-negative organism typically associated with nosocomial infections. It is an emerging multi-drug resistant pathogen associated with significant morbidity and mortality in hospitalized patients. Optimal therapy is unknown. In this study, we evaluated the impact of treatment agent, dosing regimen, and patient characteristics on 30-day mortality for Stenotrophomonas bacteremia in our hospital system. Methods Retrospective chart review from April 2013 to September 2019 at Ronald Reagan and Santa Monica UCLA Medical Centers in Los Angeles, California. Adult patients who were hospitalized and received active therapy for Stenotrophomonas bacteremia were included in the study. Chi-square or Fischer test was used for categorical variables, Student’s t-test or Mann-Whitney U test was used for continuous variables. Results Sixty-nine patients were included in the study. The median age was 53 and 31 patients (44.9%) were female. Central line associated infections were the most common source of infection (79.7%, n = 55). Two patients (3%) had a relapse of infection. The overall 30-day mortality was 30.4% (n=21). The patients who did not survive to 30 days tended to have a higher Pitt bacteremia score, a longer length of stay, and were more likely to have used other antibiotics in the 30 days prior to culture collection. Trimethoprim-sulfamethoxazole (TMP-SMX) was the most common antibiotic used for treatment (n = 45, 65.2%). Of the patients who were treated with TMP-SMX, 19 were treated with high-dose (defined as 15 mg/kg or equivalent) and 26 had an alternative dosage after adjusting for renal function. There was no difference in 30-day mortality in the TMP-SMX high dose vs alternative dose (42.1% vs 30.8%, p = 0.53). Conclusion Stenotrophomonas bacteremia was associated with high mortality. High-dose TMP-SMX did not impact survival in our study; however, this may be due to small sample size. More research is needed to determine optimal therapy. Disclosures All Authors: No reported disclosures

Sign in / Sign up

Export Citation Format

Share Document